ARTICLE | doi:10.20944/preprints201912.0214.v1
Subject: Materials Science, Other Keywords: geopolymers; metakaolin; biomass bottom ash; mechanical properties
Online: 16 December 2019 (11:15:41 CET)
In this research, the feasibility of using bottom ashes generated by the combustion of biomass (olive pruning and pine pruning) as a source of aluminosilicates (OPBA) has been studied, replacing the metakaolin precursor (MK) in different proportions (0, 25, 50, 75 and 100 wt. % substitution) for the synthesis of geopolymers. As alkaline activator an 8 M NaOH solution and a Na2SiO3 have been used. The geopolymers were cured 24 hours in a climatic chamber at 60 ° C in a water-saturated atmosphere, subsequently demoulded and cured at room temperature for 28 days. The results indicated that the incorporation of OPBA waste, which have 19.7 wt. % of Ca, modifies the characteristics of the products formed after alkaline activation. In general terms, the incorporation of increasing amounts of calcium-rich ashes results in geopolymers with higher bulk density. The compressive strength increases with the addition of up to 50 wt. % of OPBA with respect to the control geopolymers, contributing the composition of the residue to the acquisition of a better behaviour mechanical. The results indicate the potential use of these OPBA waste as raw material to produce unconventional cements with 28-day curing strengths greater than 10 MPa, and thermal conductivities less than 0.35 W/mK.
ARTICLE | doi:10.20944/preprints202008.0484.v1
Subject: Earth Sciences, Environmental Sciences Keywords: BECCS; bioenergy with carbon capture and sequestration; bioenergy; biopower; biomass resources; biomass logistics; biomass economics
Online: 21 August 2020 (11:15:15 CEST)
Bioenergy with carbon capture and sequestration (BECCS) is one strategy to remove CO2 from the atmosphere. To assess the potential scale and cost of CO2 sequestration from BECCS in the US, this analysis models carbon efficiencies and costs of biomass production, delivery, power generation, and CO2 capture and sequestration in saline formations. The analysis includes two biomass supply scenarios (near-term and long-term), two biomass logistics scenarios (conventional and pelletized), two generation technologies (pulverized combustion and integrated gasification combined cycle), and three cost accounting scenarios (gross cost, net cost after electricity revenues, and net cost after electricity revenues with avoided emissions from conventional power generation). Results show cost Mg-1 CO2 as a function of CO2 sequestered (simulating capture up to 90% of total CO2 sequestration potential) and associated spatial distribution of resources and generation locations for the array of scenario options. Under a near-term scenario using 222 million Mg yr-1 of biomass, up to 196 million Mg CO2 can be sequestered at scenario-average costs ranging from $60 to $158 Mg 1 CO2; under a long-term scenario using 823 million Mg yr-1 of biomass, up to 727 million Mg CO2 yr 1 can be sequestered at scenario-average costs ranging from $32 to $242 Mg-1 CO2. These costs are largely influenced by cost accounting scenario, and the CO2 sequestration potential may be reduced if future competing demand reduces resource availability. Results suggest there are multiple feedstock-logistics-generation pathways toward CO2 drawdown that could be incrementally trialed and monitored for environmental sustainability effects. Interactive visualization of results is available at [final link to be determined].
Subject: Biology, Forestry Keywords: aboveground biomass, Belowground biomass, Biteyu forest, Carbon stocks, disturbance
Online: 14 July 2021 (14:07:11 CEST)
The carbon stocks in the forests originated from the atmosphere and are accumulated in the organic matter of trees and soils. Forests play major roles in providing ecosystem services like climate change mitigation through carbon sequestration and nutrient flow dynamics. Therefore, the major objective of this study was to estimate carbon stocks of Biteyu forest by quantifying the aboveground biomass of trees, belowground carbon, soil carbon, and carbon stocks of litter pool. Systematic sampling technique was employed for vegetation and carbon data collection. The total of 10 line transects were laid along elevational gradients. The transects were 500 m apart and sampling plots were 300 m apart from each other. Each transect has comprised of a minimum of 4 plots to a maximum of six totaling 50 plots representing the forest for the investigation. A square sample plot of 900 m2 was used to collect vegetation data with a DBH ≥ 2.5 cm and a height of 2 m and above. To sample herbaceous vegetation in the forest floor, five smaller subplots of 1 m x 1 m = 1 m2 (four at the corner and one at the centre of the main plot) were established. The disturbance level was also determined using the cattle interference and selective cutting of trees. The appropriate allometric models were applied for both aboveground and belowground biomass estimations. The findings showed that cattle interference affects the forest understory from growing and recruitment. The mean of cattle interference was 4.77±2.12 per ha and the mean of wood stump was 26.67±9.37 per ha. The size class analysis showed that the smallest diameter class (2.5-10 cm) in the forests represented 37.05% of the total stem density. The diameter classes between 10 and 30 cm comprised a stem density of 41.08%. It was estimated that the total carbon stock of Biteyu forest was about 166.67 ± 16.4 ha-1. The carbon stock in AGB and BGB was estimated to be 87.13 ± 11.80 t ha-1 and 22.94 ± 2.84 t ha-1, respectively. Moreover, the contribution of soil and litter carbon pools to the total carbon in the forest ecosystem were 56.37 ± 1.73 and 0.26 ± 0.01 t ha-1 , respectively. From the present study it can be concluded that estimated mean carbon stock of the forest is smaller than that of other similar forests in the dry evergreen montane forest, which was attributed to the higher anthropogenic disturbances. Therefore, the interventions, which reduce the climate change effect, would be very important in the maintenance of forest ecosystem functioning.
ARTICLE | doi:10.20944/preprints201705.0178.v1
Subject: Biology, Forestry Keywords: aboveground biomass; GMM; allometry; biomass allocation; machine learning technique
Online: 24 May 2017 (10:28:21 CEST)
This paper presents new above-ground biomass (AGB) and biomass components equations for seventeen forest species in the temperate forests of northwestern Mexico. A data set corresponding to 1336 destructively sampled oak and pine trees was used to fit the models. Generalized method of moments was used to simultaneously fit systems of equations for biomass components and AGB, to ensure additivity. Additionally, the carbon content of each tree component was calculated by the dry combustion method, in a TOC analyser. The fitted equations accounted for on average 91, 83, 84 and 78% of the observed variance in stem wood and stem bark, branch and foliage biomass, respectively, whereas the total AGB equations explained on average 93% of the total observed variance in AGB. The inclusion of h or d2h as additional predictor in the d-only based equations systems slightly improved estimates of stem wood, stem bark and total above-ground biomass, and greatly improved the estimates produced by the branch and foliage biomass equations. The fitted equations were used to estimate AGB stocks at stand level from a database on growing stock from 429 permanent sampling plots. Three machine-learning techniques were used to model the estimated stand level AGB and carbon contents; the selected models were applied to map the AGB and carbon distributions in the study area, which yielded mean values of 129.84 Mg ha-1 and 63.80 Mg ha-1, respectively.
ARTICLE | doi:10.20944/preprints202012.0477.v1
Subject: Keywords: Above ground biomass; Anthropogenic; Below ground biomass; Carbon sequestration; Forest
Online: 18 December 2020 (15:18:24 CET)
Carbon sequestration is associated with plant biomass and soils. The amount of carbon sequestration in the Atewa Range Forest Reserve (ARFR) is affected by varied anthropogenic activities like logging, mining and farming. This study estimate the above and below ground carbon stock and assess human-induced stress impacts on the Highly Stressed Vegetation (HSV), Moderately Stressed Vegetation (MSV), and Non-Stressed Vegetation (NSV) in the ARFR. The above ground biomass of trees was determined using the allometric model of (Henry, et al., 2010) whereas plants root biomass was calculated using Cairns et al. (1997). Soil organic carbon was determined using the Walkley–Black method. We observed that carbon stock was higher in the above-ground than the below-ground component. The MSV, recorded the highest stock of carbon followed by the NSV and the HSV whilst sequestrated carbon stocks was generally high and varied across the three stress levels. Within the forest, the intensity of anthropogenic activities has negatively impacted the amounts of carbon sequestrated at various levels.
ARTICLE | doi:10.20944/preprints201905.0019.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: biochar; phytoextraction; corn; uptake; mine soils; heavy metals; root biomass; shoot biomass
Online: 5 May 2019 (12:11:59 CEST)
Mining activities could produce a large volume of spoils, waste rocks, and tailings, which are usually deposited at the surface and become sources of metal pollution. Phytostabilization of the mine spoils could limit the spread of these heavy metals. Phytostabilization can be enhanced by using soil amendments like manure-based biochar capable of immobilizing metal(loid)s when combined with plant species that are tolerant of high levels of contaminants while simultaneously improving properties of mine soils. However, the use of manure-based biochar and other organic amendments for mine spoil remediation are still unclear. In this greenhouse study, we evaluated the interactive effect of biochar application and compost on shoots biomass yield (SBY), roots biomass yield (RBY), uptake, and bioconcentration factor (BCF) of Zn and Cd in corn (Zea mays L.) grown in mine soil. Biochar sources (BS) consisted of beef cattle manure (BCM); poultry litter (PL); and lodge pole pine (LPP) were applied at 0, 2.5, and 5.0% (w/w) in combination with different rates (0, 2.5, and 5.0%, w/w) of cattle manure compost (CMC), respectively. Shoots and roots uptake of Cd and Zn were significantly affected by BS, CMC, and the interaction of BS and CMC. Corn plants that received 2.5% PL and 2.5% BCM had the greatest Cd and Zn shoot uptake, respectively. Corn plants with 5% BCM had the greatest Cd and Zn root uptake. When averaged across BS, the greatest BCF for Cd in the shoot of 92.3 was from the application BCM and the least BCF was from the application of PL (72.8). Our results suggest that incorporation of biochar enhanced phytostabilization of Cd and Zn with concentrations of water-soluble Cd and Zn lowest in soils amended with both manure-based biochars while improving biomass productivity of corn. Overall, phytostabilization technique and biochar application have the potential to be combined in the remediation of heavy metals polluted soils.
ARTICLE | doi:10.20944/preprints201904.0215.v1
Subject: Engineering, Energy & Fuel Technology Keywords: biomass; xylan; lignin; cellulose; pretreatment
Online: 19 April 2019 (09:52:04 CEST)
For the effective utilization of rice husk, organosolv fractionation was investigated to separate three main components (glucan, xylose, and lignin) with low acid concentration. Reaction temperatures of 170–190 °C, ethanol concentrations of 50–70% (v/v), and sulfuric acid concentrations of 0–0.7% (w/v) were investigated, with the reaction time and liquid-to-solid ratio kept constant at 60 min and 10, respectively. The fractionation conditions for the efficient separation into the three components of rice husk were determined to be 180 °C, 60% (v/v) of ethanol, and 0.25% (w/v) of sulfuric acid. Under these fractionation conditions, 86.8% of the xylan and 77.5% of the lignin were removed from the rice husk, and xylose and lignin were obtained from the liquid in 67.6% and 49.8% yields, respectively. The glucan digestibility of the fractionated rice husk was 85.2% with an enzyme loading of 15 FPU (filter paper unit) of cellulase per g-glucan.
CASE REPORT | doi:10.20944/preprints201806.0465.v1
Online: 28 June 2018 (11:12:33 CEST)
A E. Crassipes is considered a problem in different aquatic ecosystems, due to its abundance could become a solution to design and build economic and efficient treatment plants, and especially for the production of biofuels such as bioethanol. The objective of this research is to design and implement a sustainable development process between phytoremediation and bioethanol production with E. crassipes, evaluating the incidence of chromium adhered to the biomass of this plant in the production of bioethanol. Materials and methods: A system was installed to evaluate the phytoremediation with E crassipes with water loaded with chromium, determining the effectiveness of this plant to remove this heavy metal even if it is alive in a body of water. After this process, we proceeded to bring the biomass loaded with chromium to bioreactors to evaluate the production of bioethanol, assessing three types of biomass, one without chromium adhered and the other two with chromium adhered to its plant structure. There was an impact of the ethanol production of the E crassipes due to the presence of chromium, but this production can be taken into account for the assembly of an integral system of phytoremediation and bioethanol production, making the most of this biomass.
ARTICLE | doi:10.20944/preprints201712.0087.v1
Subject: Materials Science, Biomaterials Keywords: pyrolysis; biomass; biochar; Taguchi; optimization
Online: 14 December 2017 (08:03:42 CET)
This research demonstrates the optimization and production of biochar from barley husk (BH), corn cob (CC), and Agave salmiana leaves (AL) via pyrolysis in a muffle furnace. Taguchi experimental design (L9) was applied to conduct the experiments at different levels by altering four operating parameters. Carbonization temperature (300–500 ºC), carbonization time (30–90 min), precursor mass (2–5 g) and N2 flow rate (100–200 cc/min) were the variables examined in this study. The effect of the parameters on the biochar yield was investigated, and the important parameters were identified employing analysis of variance (ANOVA). The optimum conditions for maximum biochar yield were: carbonization temperature of 400 ºC, carbonization time of 30 min, precursor mass of 2 g, and N2 flow rate of 150 cc/min. The biochars produced under optimum conditions was characterized physically and chemically. Biochar yields of 19.75% for corn cob (CCB), 32.88% for barley husk (BHB), and 31.14% for agave leaves (ALB) were obtained.
ARTICLE | doi:10.20944/preprints201809.0393.v1
Subject: Engineering, Energy & Fuel Technology Keywords: exchange current; energy efficiency; heat generation; attached biomass; suspended biomass; single chamber air-cathode
Online: 20 September 2018 (04:10:40 CEST)
The model proposed in this study was based on the assumption that the biomass attached to the anode served as biocatalysts for MFC exoelectrogenesis, and this catalytic effect was quantified by the exchange current density of anode. By modifying the Freter model and combining it with the Butler-Volmer equation, this model could adequately describe the processes of electricity generation, substrate utilization, and the suspended and attached biomass concentrations, at both batch and continuous operating modes. MFC performance is affected by the operating variables such as initial substrate concentration, external resistor, influent substrate concentration, and dilution rate, and these variables were revealed to have complex interactions by data simulation. The external power generation and energy efficiency were considered as indices for MFC performance. The simulated results explained that an intermediate initial substrate concentration (about 100 mg/L under this reactor configuration) needed to be chosen to achieve maximum overall energy efficiency from substrate in the batch mode. An external resistor with the value about that of the internal resistance boosted the power generation, and a resistor with several times of that of the internal resistance achieved better overall energy efficiency. At continuous mode, dilution rate significantly impacted the steady-state substrate concentration level (thus substrate removal efficiency and rate), and attached biomass could be fully developed when the influent substrate concentration was equal to or higher than 100 mg/L at any dilution rate of the tested range. Overall, this relatively simple model provided a convenient way for evaluating and optimizing the performance of MFC reactors by regulating operating parameters.
ARTICLE | doi:10.20944/preprints202206.0154.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Above ground biomass; allometric equation; forest conservation; climate change mitigation; Biomass; carbon dioxide; carbon Sequestration
Online: 10 June 2022 (08:15:38 CEST)
Forests play an important role in reducing greenhouse gases in the atmosphere, thereby mitigating the impact of climate change. Estimating the accumulated biomass in a forest ecosystem is important for assessing the productivity and sustainability of the forest. Allometric models for above ground biomass (AGB) are linear regression equations based on the relationships between biomass and diameter at breast height (DBH), tree height (H), and/or wood density. This study estimates AGB in the Colo-I-Suva Forest Park by applying the allometry of Chave et al (2005) and the diameter: height ratio derived from Payton & Weaver (2011) for height estimation in a plot of 20
ARTICLE | doi:10.20944/preprints202104.0715.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: energy crops; land use; biomass; bioenergy
Online: 27 April 2021 (12:38:38 CEST)
Research Highlights: (1) Reed canary grass (RCG) is analysed in Sweden compared to willow and poplar for 2001-2020 (2) Each crop presents a different land-use and climatic profile (3) Average yield records of reed canary grass are similar to willow and poplar (4) There are divergences between trial-based and commercial yields (5) Existing LUC patterns suggest meadow>RCG and RCG>cereal (6) RCG land area is very sensitive to policy incentives. Background and objectives: RCG is an alternative crop for biomass-to-energy due to high yield and frost tolerance. We assess the cultivation in Sweden by using an extensive compilation of data, with emphasis on the extension of the cultivation, areas planted, climatic profile, land use patterns and yield levels. Material and methods: All RCG plantations are analysed for 2001-2020. A geostatistical analysis is performed to characterize where is cultivated and the land uses associated. Climatic, productivity and yield profiles are compared to willow and poplar plantations, from experiments and from commercial plantations. Results: The results show that the cultivation of reed canary grass expanded after 2005, with a maximum of 800 ha in 2009 to then decrease to the current levels of about 550 ha. It is mainly grown in colder climatic areas, with lower agricultural productivity than willow and poplar. Mean yields from trials are 6 odt ha-1 yr-1; commercial yields are 3.5 odt ha-1 yr-1. RCG replace meadow land and is replaced by cereals, when abandoned. Conclusions: Reed canary grass is an interesting alternative, growing on colder areas but on similar yield levels than other energy crops. The cultivation is more sensitive to policy incentives
ARTICLE | doi:10.20944/preprints201811.0298.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: degraded land; biodiesel; biomass; energy; Indonesia
Online: 13 November 2018 (05:17:34 CET)
This study spatially estimates degraded lands in Indonesia that have limited functions for food production, carbon storage, and conservation of biodiversity and native vegetation, and examines their suitability to grow biodiesel species (Calophyllum inophyllum, Pongamia pinnata and Reutealis trisperma) and biomass species (Calliandra calothyrsus and Gliricidia sepium). Results showed that Indonesia has ∼3.5 million ha of degraded lands potentially suitable for these species. With the all-five-species scenario, these lands had the potential to produce 1105 PJ yr−1 of biomass and 3 PJ yr−1 of biodiesel. With the biodiesel-only-species scenario, these lands showed the potential to produce 10 PJ yr−1 of biodiesel. Despite this energy potential, however, the land sizes were too small to support economies of scale for biofuel production. The study findings contribute to identifying lands with limited functions, modeling biofuel-species growth on regional lands and estimating carbon stocks of restored degraded lands in Indonesia.
ARTICLE | doi:10.20944/preprints201809.0419.v1
Subject: Life Sciences, Biotechnology Keywords: Lignocellulosic biomass; cellulose; hemicellulose; lignin; biofuel
Online: 20 September 2018 (16:16:47 CEST)
Carbohydrate composition of lignocellulosic biomass is one of the main factors for production of biofuel from the plant biomass. Various methods like Thermogravimetric analysis (TGA), near infrared spectroscopy (NIR) often used in determination of polysaccharide component of the plant biomass. However, used of such tools is based on the prediction and very costly. This paper discussed about the determination of carbohydrate composition (cellulose, hemicellulose and lignin) using the automatic fibre estimation system. The protocol was developed for the estimation of cellulose, hemicellulose and lignin component of lignocellulosic biomass. This protocol explains a simple method to estimate the polysaccharide component of lignocellulosic biomass. This protocol can be used not only lignocellulosic biomass but also for other hardwood biomass. The advantages and techniques, procedures are presented below.
ARTICLE | doi:10.20944/preprints201807.0114.v1
Subject: Materials Science, Biomaterials Keywords: biomass; briquette; combustion; density; energy source
Online: 6 July 2018 (09:48:02 CEST)
This study investigated the physical and combustion properties of briquettes produced from agricultural wastes (groundnut shells and corn cobs), wood residues (Anogeissus leiocarpus) and admixtures of the particles at 15%, 20% and 25% starch levels (binder). A 6 x 3 factorial experiments in a Completely Randomized Design (CRD) was adopted for the study. The briquettes produced were analyzed for density, volatile matter, ash content, fixed carbon and specific heat of combustion. The result revealed that the density ranged from 0.44g/cm3 to 0.53g/cm3, while briquettes produced from groundnut shells had the highest (0.53g/cm3) significant mean density. Mean volatile matter and ash content of the briquettes ranged from 24.35% to 34.95% and 3.37% to 4.91%. A. leiocarpus and corn cobs particles had the lowest and highest ash content respectively. The briquette fixed carbon and specific heat of combustion ranged from 61.68% to 68.97% and 7362kca/kg to 8222kca/kg respectively. Briquette produced from A. leiocarpus particles had the highest specific heat of combustion. In general, briquettes produced from A. leiocarpus particles and admixture of groundnut shell and A. leiocarpus particles at 25% starch level had better quality in terms of density and combustion properties and thus suitable as environmentally friendly alternative energy source.
ARTICLE | doi:10.20944/preprints201807.0084.v1
Online: 5 July 2018 (08:09:35 CEST)
The case for demand-driven research and development has received important considerations among governments, donors and programme implementing partners in development planning and implementation. Addressing demand is believed to be a bottom-top approach for designing and responding to development priorities and is good for achieving development outcomes. In this paper, we discuss the concept and application of demand driven research for development (DDRD) in Africa. We use evidence of six projects implemented under the BiomassWeb Project in Africa. We focus on parameters on level of engagement of stakeholders - whose demand is being articulated, the processes for demand articulation, capacity building and implementation processes, innovativeness of the project, reporting and sustainability of the project. We find that the nature of the institutions involved in articulation and implementation of demand-driven research and development projects and their partnerships influence the impact and reporting of demand-driven projects.
ARTICLE | doi:10.20944/preprints202211.0284.v1
Subject: Life Sciences, Biotechnology Keywords: microalgae; biomass; photosynthesis; mixotrophic; LC-MS/MS
Online: 15 November 2022 (09:54:52 CET)
NH4Cl is one of the nitrogen sources for microalgal cultivation. However, excessive amounts of NH4Cl affects microalgal physiology and biomass contents. In this study, the effects of ammonium on microalgal growth and TAG content in the green microalga (Chlamydomonas reinhardtii) was investigated. Microalgal growth and TAG content under photoautotrophic conditions were found to be unchanged with 17 mM of ammonium, while this compound interfered with microalgal growth and induced TAG content under mixotrophic conditions with acetate supplementation. This suggested that ammonium could induce TAG production when acetate occurred in microalgal cultivation. Further, the effects of two different concentrations of NH4Cl (17 mM and 60 mM) on the cells under mixotrophic conditions were investigated. The results showed that both concentrations reduced microalgal growth, but induced total lipid and TAG content, especially after a 4-day cultivation. The oxygen evolution and Fv/Fm ratio showed that both concentrations completely inhibited the oxygen evolution on Day 4. The 60 mM NH4Cl reduced the Fv/Fm ratio from 0.7 to 0.48 indicating that ammonium supplementation directly affects the microalgae photosynthesis performance. A total of 1782 proteins were successfully identified using proteomics analysis. Among them, there were nine overexpressed proteins and four proteins were underexpressed. Using the protein–ligand interaction analysis, nitrogen metabolism is involved under NH4Cl conditions. This information can provide biochemical knowledge for microalgae development for sustainable energy usage.
ARTICLE | doi:10.20944/preprints202201.0201.v1
Subject: Earth Sciences, Environmental Sciences Keywords: wastewater; valuable algal biomass; nitrogen; phosphorus; jellyfish
Online: 14 January 2022 (11:18:16 CET)
The introduction of organic and inorganic substances to the environment is a result of human activities such as agriculture, domestic and industrial wastewater which leads to pollution. Treatment processes of these wastewaters are being conducted globally to eliminate easily settled materials and recover nutrients in an attempt to release clear and apparently clean effluent into natural waters. Lack of removing inorganic nitrogen and phosphorus nutrients is the greatest cause of eutrophication in water bodies which inhibits the life of other organisms as well as pose a threat to human life and loss of the economy. Different technologies have been applied and are being developed to recover nutrients as well as heavy metals from wastewater to meet the permissible limits before discharging effluents. Wastewater treatment using microalgae offers an opportunity to provide tertiary bio-treatment and production of valuable biomass. Microalgae use the available inorganic nitrogen and phosphorus for their growth which are then harvested for various uses. Additionally, they have the ability to remove heavy metals and some toxic compounds. The main specific microalgae species in this study is the Chlorella sorokiniana with the Aequorea victoria jellyfish This paper reviews some of the wastewater treatment processes and focus on the use of microalgae and some of the shortcomings of the technologies and how they can be improved to achieve maximum nutrient recovery economically with low energy demand.
ARTICLE | doi:10.20944/preprints201908.0030.v1
Subject: Chemistry, Physical Chemistry Keywords: biomass pyrolysis; alcohol dehydration; zeolite; DFT; ONIOM
Online: 2 August 2019 (10:50:24 CEST)
In the upgrading of biomass pyrolysis vapors to hydrocarbons, dehydration accomplishes a primary objective of removing oxygen and acidic zeolites represent promising catalysts for dehydration reaction. Here, we utilize density functional theory calculations to estimate adsorption energetics and intrinsic kinetics of alcohol dehydration over H-ZSM-5, H-BEA, and H-AEL zeolites. ONIOM calculations of adsorption energies were observed to be inconsistent when benchmarked against QM/Hartree-Fock and periodic boundary condition calculations. However, reaction coordinate calculations of adsorbed species and transition states were consistent across all levels considered. Comparison of ethanol, iso-propanol (IPA), and tert-amyl alcohol (TAA) over these three zeolites allowed for a detailed examination of how confinement impacts reaction mechanisms and kinetics. TAA, seen to proceed via a carbocationic mechanism, was found to have the lowest activation barrier, followed by IPA and then ethanol, both of which dehydrate via a concerted mechanism. Barriers in H-BEA were consistently found to be lower than in H-ZSM-5 and H-AEL, attributed to late transition states and either elevated strain or inaccurately estimating long-range electrostatic interactions in H-AEL, respectively. Molecular dynamics simulations revealed that the diffusivity of these three alcohols in H-ZSM-5 are significantly overestimated by Knudsen diffusion, which will complicate experimental efforts to develop a kinetic model for catalytic fast pyrolysis.
ARTICLE | doi:10.20944/preprints201904.0231.v1
Subject: Engineering, Energy & Fuel Technology Keywords: bioethanol; biomass; buckwheat straw; ionic liquid; pretreatment
Online: 22 April 2019 (10:50:32 CEST)
Common buckwheat (Fagopyrum esculentum Moench) is an annual spring-emerging crop that is classified among dicotyledons, yet due to the manner of its cultivation, use, and chemical composition of seeds. The use of buckwheat straw for energy purposes, for example, for the production of second generation bioethanol might enable its wider application and increase the cost-effectiveness of tillage. In this study, we examined the usability of buckwheat straw for the production of bioethanol. We pretreated the raw material with using ionic liquids and subsequently performed enzymatic hydrolysis and alcoholic fermentation. The obtained chemometric data was analyzed using the Partial Least Squares (PLS) regression model. PLS regression in combination with the spectral analysis within near-infrared (NIR) spectrum allowed for the rapid determination of amount of cellulose in the raw material and also provided information on the changes taking place in its structure. According to our results, we obtained good results for the combination of 1-ethyl-3-methylimidazolium acetate as the ionic liquid and Cellic CTec2 and the enzymatic preparation for the pretreatment of buckwheat straw. The highest concentration of glucose following 72 hours of enzymatic hydrolysis was found to be around 5.5 g/dm3. The highest concentration of ethanol (3.31 g/dm3) was obtained with the combination of 1-butyl-3-methylimidazolium acetate for the pretreatment and the cellulase from Trichoderma reesei for enzymatic hydrolysis. In summary, the efficiency of the fermentation process is strictly associated with the pool of available fermenting sugars, and it depends on the type of ionic liquid used during the pretreatment and on the enzymatic preparation. It is possible to obtain bioethanol from buckwheat straw using ionic liquid for the pretreatment of the raw material prior to the enzymatic hydrolysis and alcoholic fermentation of the material.
REVIEW | doi:10.20944/preprints201809.0336.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Adsorption; Emerging contaminants; Biomass; Biochar; Activated carbon
Online: 18 September 2018 (09:06:00 CEST)
This review analyzes the synthesis and characterization of biomass-derived carbons for adsorption of emerging contaminants from water. The study begins with the definition and different types of emerging contaminants more often founded in water streams and the different technologies available for their removal including adsorption. It also describes the biomass sources that could be used for the synthesis of biochars and activated carbons. The characterization of the adsorbents and the different approaches that could be employed for the study of the adsorption processes are also detailed. Finally, the work reviews in detail some studies of the literature focused on the adsorption of emerging contaminants on biochars and activated carbons synthesized from biomass precursors.
ARTICLE | doi:10.20944/preprints201807.0489.v1
Subject: Chemistry, Physical Chemistry Keywords: CO2 adsorption, CH4 adsorption, biomass, activated carbon.
Online: 25 July 2018 (15:29:22 CEST)
The aim of the present study is to provide new insights into the CO2 and CH4 adsorption using a set of biomass-based activated carbons obtained by physical and chemical activation of olive-stones. The adsorption behavior is analyzed by means of pure gas adsorption isotherms up to 3.2 MPa at two temperatures (303.15 and 323.15 K).The influence of the activation method on the adsorption uptake is studied in terms of both textural properties and surface chemistry. For three activated carbons the CO2 adsorption was more important than that of CH4. The chemically activation resulted in higher BET surface area and micropore volume that lead to higher adsorption for both CO2 and CH4. For methane the presence of mesopores seems to facilitate the access of the gas molecules into the micropores while for carbon dioxide, the presence of oxygen groups enhanced the adsorption capacity.
ARTICLE | doi:10.20944/preprints201804.0042.v1
Subject: Life Sciences, Other Keywords: geospatial economic supply; biomass; risk assessment; vulnerability
Online: 4 April 2018 (04:17:33 CEST)
Assessing the economic supply of biomass in a geospatial context while accounting for risk from natural disasters was studied. Risk levels were estimated from a component of factors which included: population density, road density, federal ownership, U.S. Environmental Protection Agency ecoregions, and Presidential Disaster Declarations. The Presidential Disaster Declarations included risks due to: coastal storm, drought, fire, flood, freezing, hurricane, mud land slide, severe ices, severe storms, snow, tornado, and tropical storm. Presidential Disaster Declarations included summaries based on a short-term time period from 2000-2011, and on a long-term time period from 1964-2011. Risk categories were developed as a function of the number of disaster declarations, agricultural-to-forest land ratio, average road density, and average population density. A significant contribution of the research was the allocation of spatially explicit data using GIS technology at the 5-digit zip code tabulation area. The average area for 5-digit ZCTAs in the Eastern U.S. study region was approximately 169 kilometers2. Long-term risk (1964-2011) from disaster declarations had a greater impact on the economic availability of biomass supply relative to short-term declarations (2000-2011). The greatest risk to biomass supply came from population density relative to the other risk factors studies. Of the 25,044 total ZCTAs, 12,256 ZCTAs were in locations that did not include population density ≥ 150/km2, road density ≥ 14 km/km2, federal ownership, and US Environmental Protection Agency Level III ecoregions. Of the remaining 12,256 ZCTAs, 26.8% were considered to be moderate-to-high risk based on short-term declarations (2000-2011) and 29.4% were considered to be moderate-to-high risk based on long-term declarations (1964-2011). Lower risk locations for procuring biomass supply for both short-term and long-term declarations, across all risk factors, were in southern Georgia, South Carolina, and Texas.
ARTICLE | doi:10.20944/preprints201802.0158.v1
Subject: Engineering, Energy & Fuel Technology Keywords: biomass; functions; innovation systems; renewable energy; Malaysia
Online: 26 February 2018 (09:41:32 CET)
Malaysia generates significant quantities of Oil Palm Wastes (OPW) which can be potentially valorised into sustainable bioenergy as envisaged by the National Biomass Strategy (NBS-2020). Despite significant investments, policy directives and government support, the valorisation of OPW into bioenergy has remained low exacerbating waste management challenges. Therefore, the strategies and impediments to the rapid bioenergy development and bioelectricity generation from OPW require practical assessment. Therefore, this paper examines the level of development and diffusion of the biomass innovation system in Malaysia based on the Functions of Innovations Systems (FIS) approach developed by Dutch and Swedish researchers. Furthermore, the key factors hindering biomass energy technologies implementation in Malaysia and potential solutions were identified, highlighted and examined. Based on the FIS analysis the functions; entrepreneurial activities, knowledge development, and resources mobilization functions are well established in the Malaysian biomass innovation system (BIS). However, the functions of guidance of search; creation of legitimacy; knowledge diffusion and market formation are underdeveloped resulting in the low penetration of bioenergy in Malaysia. Other factors include; fossil fuel subsidies, numerous or conflicting energy policies and weak collaboration between academia and the industry. The outlined challenges can be addressed by revising fuel subsidies, Feed-in tariffs, RETs implementation, roles of supervisory agencies, and bureaucratic procedures for access to funds for research and development of bioenergy in Malaysia.
ARTICLE | doi:10.20944/preprints201705.0179.v1
Subject: Engineering, Energy & Fuel Technology Keywords: WEEE; ASR; briquette; physical properties; biomass blend
Online: 24 May 2017 (17:14:42 CEST)
In this study, the physical properties of briquettes produced from two different biomass feedstocks (sawdust and date palm trunk) and different plastic wastes were investigated, without using any external binding agent. The biomass feedstocks were blended with different ratios of two WEEE plastics (halogen-free wire and print circuit boards (PCB)) and automotive shredder residues (ASR). The briquettes production is studied at different waste proportions (10-30%), pressures (22-67 MPa) and temperatures (room-130 ˚C). Physical properties as density and durability rating were measured, usually increasing with temperature. Palm trunk gave better results than sawdust in most cases, due to its moisture content and the extremely fine particles that are easily obtained.
ARTICLE | doi:10.20944/preprints201704.0020.v1
Subject: Earth Sciences, Environmental Sciences Keywords: biomass, carbon stock, wetland, spectral radiance, SWIR
Online: 4 April 2017 (10:02:56 CEST)
The assessment of biomass carbon stocks was conducted at plot scale as a sample to estimate for all vegetation areas by using destructive sampling and or allometric equation method. Remote sensing is one of the techniques can be used to estimate and mapping biomass carbon stock for the entire areas. The objectives of the study are the identification and determine the range of electromagnetic wave of Landsat 8 satellite data that most suitable for assessing and mapping biomass carbon stock distribution. This research analyses exponential regression equation between spectral radiance values (Lλi) for with biomass measurement results on the field to find the best correlation based on the coefficient of determination value (R2). It also analyses the relationship between field biomass and NDVI value (Normal Differences Vegetation Index) from satellite data. The study area consists of 54.9% bush (Bs), 24.5% scrub (Sc), 16.8% secondary forest (Sf), while the rest (3.8%) is a water body. The with average biomass carbon stock value 4.11 tons.ha-1, 64.43 tons.ha-1, and 85.36 tons.ha-1, for strata Sc, Bs, and Sf respectively. Spectral radiance of SWIR (Shortwave Infra-Red) band 6 is determined as a spectral characteristic that can be used to estimating carbon stock with following the equation Y= 12657(EXP(-0.642(Lλband6)) with r2 = 0.75. Correlation NDVI and field biomass showed the low r2 value (0.08), so in this study, NDVI cannot be used to estimate the biomass carbon stock.
ARTICLE | doi:10.20944/preprints202212.0158.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: U-Net; Carbon Storage; Above-Ground Biomass; Remote Sensing; Deep Learning; CNN; Sentinel-2; ESA CCI Biomass Project
Online: 8 December 2022 (10:26:17 CET)
United Nations Framework Convention on Climate Change (UNFCCC) has recently established the Reducing Emissions from Deforestation and forest Degradation (REDD+) program that requires countries to report their carbon emissions and sink estimates through national greenhouse gas inventories (NGHGI). Thus, developing automatic systems capable of estimating the carbon absorbed by forests without in-situ observation becomes essential. To support this important need, in this work we introduce ReUse, a simple but effective deep-learning approach to estimate the carbon absorbed by forest areas based on remote sensing. The novelty of the proposed method is in the use of the public above-ground biomass (AGB) data from the European Space Agency's Climate Change Initiative Biomass project as ground truth to estimate the carbon sequestration capacity of any portion of land on Earth using Sentinel-2 images and a pixel-wise Regressive UNet. The approach has been compared to two literature proposals, using a private dataset and human-engineered features. The results show a greater generalization ability of the proposed approach, with a decrease in Mean Absolute Error and Root Mean Squared Error, respectively, of 16.9 and 14.3 in the area of Vietnam and 4.7 and 5.1 in the area of Myanmar over the runner-up. Finally, as a case study, we reported an analysis made for the Astroni area, a nature reserve located near the metropolitan area of Naples in southern Italy, struck by a large fire, producing predictions consistent with values found by experts in the field. These results further support the use of such an approach for the early detection of AGB variations, both in urban and rural areas.
ARTICLE | doi:10.20944/preprints201801.0275.v1
Subject: Earth Sciences, Environmental Sciences Keywords: forest biomass; aboveground biomass; airborne lidar; monitoring; regional forest inventory; variable selection; Bayesian model averaging; multiple linear regression
Online: 30 January 2018 (04:05:36 CET)
Historical forest management practices in the southwestern US have left forests prone to high intensity, stand-replacement fires. Effective management to reduce the cost and impact of forest-fire management and allow fires to burn freely without negative impact depends on detailed knowledge of stand composition, in particular, above-ground biomass (AGB). Lidar-based modeling techniques provide opportunities to reduce costs and increase ability of managers to monitor AGB and other forest metrics. Using Bayesian Model Averaging (BMA), we develop a regionally applicable lidar-based statistical model for Ponderosa pine and mixed conifer forest systems of the southwestern USA, using previously collected field data. The selected regional model includes a mid and low canopy height metric, a canopy cover, and height distribution term. It explains 72% of the variability in field estimates of AGB, and the RMSE of the two independent validation data sets are 23.25 and 32.82 Mg/ha. The regional model developed is structured in accordance with previously described models fit to local data, and performs equivalently to models designed for smaller scale application. Developing regional models for broad scale application provides a cost-effective, robust approach for managers to monitor and plan adaptively at the landscape scale.
REVIEW | doi:10.20944/preprints202202.0361.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Hydropower; Wind, Solar; Geothermal; Firewood; Nuclear; Petroleum; Peat; Non-solid biomass; Solid biomass; Energy systems; Human energy; Animal energy
Online: 28 February 2022 (12:25:14 CET)
We live in the world that is completely entangled on energy and thus, Humankind can no longer do without it, power. With electricity being the main form of energy today, this has increased the complexity of our life today. In Uganda, electricity generation is mainly through hydropower which put the country in the bottleneck of over dependence on one source of energy. Yet, there are many energy systems out there that country can diversify its electricity generation. Therefore, the need to understand, the level of development and utilization of various energy systems has been the underlying question for this present study. Comprehensive literature survey was conducted from the electronic databases including ScienceDirect, Wiley, Sage, Scopus, Taylor & Francis, and Google Scholar. The publications in form of reports, conference papers, working papers, discussion papers, journal articles, book sections and textbooks were considered in this study. In total, 11 energy systems including human and animal energy, solid biomass (firewood), hydropower, wind, geothermal, solar, nuclear, peat, coal, petroleum, and non-solid biomass (methanol, hydrogen, ethanol, biodiesel, and biogas) are described. The current and the future development and utilization of these energy systems has been described. The challenges with their development and utilization were elaborated and the solution the challenges were presented. The hydropower with River Nile being the main river for large hydropower plant construction is the dominance energy system in Uganda. Nuclear energy will be the salvation for the country’s electric energy supply in the near future. Therefore, Uganda needs to bet big on nuclear energy.
REVIEW | doi:10.20944/preprints202210.0149.v1
Subject: Life Sciences, Biotechnology Keywords: Biogas; anaerobic digestion; gene mutation; bioengineering; lignocellulose biomass
Online: 11 October 2022 (10:33:29 CEST)
The demand for an efficient utilization of abundant biomasses is growing for the production of biogas and valuable bioproducts. Lignocellulose biomass is a cheap and most abundant carbon source for the production of biofuels such as bioethanol, biobutanediol, and other bio-based chemicals. Due to its complex heterogeneity, its hydrolysis gives rise to a mixture of sugars, mainly glucose; a hexose and xylose; a pentose. Glucose is the most abundant carbohydrate monomer. Most microorganisms have evolved the ability to utilize it preferably due to carbon catabolite repression regulatory mechanism at the detriment of the pentoses. Some microbes even lack the ability to utilize them. This has led to the sequential use of these sugars and accompanying reduced productivity due to inadequate utilization of the pentoses. Also, this sequential utilization of the sugars takes time and makes the overall processes economically costly. Since lignocellulose hydrolysates comprise both hexoses and pentoses, the catabolism of these sugar mixtures to biofuels will require an efficient microbial strain capable of simultaneous utilization. The use of CCR negative mutants can achieve this. CCR negative mutants simultaneously utilize pentoses and hexoses, ensuring an improved fermentation efficacy and greater productivity, thus, making the overall bioprocess economically feasible. This article reviewed several approaches employed in creating these mutant microorganisms. A brief insight on carbon catabolite repression and phosphostransferase system were made. It also highlighted the biogas production processes, factors affecting anaerobic digestion, lignocellulosic biomass structure, challenges with their use and solutions to overcoming the challenges.
ARTICLE | doi:10.20944/preprints202210.0035.v1
Subject: Earth Sciences, Atmospheric Science Keywords: PM0.1; ultrafine particles; carbon; biomass burning; vehicle exhaust
Online: 5 October 2022 (10:59:03 CEST)
Seasonal variations in atmospheric ultrafine particulate matter (PM0.1) were monitored in Bangkok, Thailand, from 2016 to 2017. PM0.1 bound organic carbon (OC), and elemental carbon (EC) were collected by a cascade air sampler that can collect PM0.1 and estimated by a thermal-optical carbon analyzer following the IMPROVE-TOR protocol. The annual average PM0.1 in Bangkok was 14.5 ± 4.7 µg/m3, higher than in large Asian cities like Shanghai and Hanoi. Biomass burning from neighboring areas was shown to increase the particle concentration. Apparent risings in carbon species as OC, EC, and OC/EC ratios in the wet and dry seasons were observed, and Char-EC/Soot-EC displayed that the PM0.1 in the Bangkok atmosphere was influenced mainly by the vehicle exhaust, even though the influence of biomass burning was more sensitive during the dry season. The effective carbon ratio (ECR) displays that carbonaceous aerosol is light-absorbing; the dry season increase contributed to climate and air quality. The finding of this work is of great importance to air pollutants control policies in urban areas.
ARTICLE | doi:10.20944/preprints202204.0066.v2
Subject: Engineering, Energy & Fuel Technology Keywords: greenhouse; biomass; carbon dioxide; capture carbon dioxide; gasification
Online: 16 May 2022 (04:50:47 CEST)
The gasification of sugarcane cutting residues (RAC) is a process that occurs in a gasifier where the transformation of this raw material into a solid-state and a gasifying agent with a moderate calorific value occurs, thanks to the application of heat. And under restricted oxygen levels, we can say that there are several styles of gasifiers for air, steam, oxygen, and hydrogen, all of which have a performance that can be analyzed and categorized by their performance to avoid damage to the environment. (1) The objective of this article is based on the mathematical development using simulation of the gasification of cane cutting residues. (2) In the methodology, the simulation of the gasification and CO2 capture process was developed from the biomass residues of the sugarcane cutting residues; it was carried out as a transformation of the primary fuel into a gas stream whose main components are CO2 and H2, which can be separated relatively easily by their concentrations, available pressures and in some cases, their temperatures; (3) According to the kinetic data obtained, the second-order reaction in the transformation and improvement of the process was identified; applying to the optimization of development in the capture of CO2, contributing to the reduction of greenhouse gases. (4) The gasification simulation process results in a biomass conversion corresponding to 93% of its feed and the formation of volatiles whose molar fraction corresponds to 37% H2, 12% CH4, 37% CO and 12 % CO2.
ARTICLE | doi:10.20944/preprints202203.0049.v1
Subject: Biology, Plant Sciences Keywords: Cotton; Fiber initiation; Cell differentiation; CYP78A; Endoreduplication; Biomass
Online: 2 March 2022 (12:32:00 CET)
Cytochrome P450 (CYPs) is a functionally diversified third-largest gene family that exploded in the plant kingdom. Their role in different organ development has been illustrated by the intervention of phytohormone. Cotton is a model organism for cell differentiation and cell elongation. To decipher the participation of CYPs in different cotton fiber developmental stages, we identified and characterized 2460 CYPs in three diploids and two allotetraploid cottons. Furthermore, In-silico expression and cluster analysis of cotton CYPs was conducted to distinguish the fiber stage-specific clusters that have the determining role in different stages of fiber development. The subgenome expression of two conserved Gossypium hirsutum CYPs, namely, GhCYP78A197 and GhCYP78A198 contributed to fiber initiation at an early stage of fiber development, governed by the co-occurrence of TATA and MYB TFs binding sites. Coexpression network partners of these two GhCYP78A annotated as auxin, kinases, chromatin remodeler, epigenetic regulator and cyclin-related genes that possibly induce the endoreduplication and cell proliferation for fiber cell initiation to define the high yield and biomass.
ARTICLE | doi:10.20944/preprints202106.0517.v1
Subject: Biology, Anatomy & Morphology Keywords: Harvest index; total biomass; fruit number; fruit length
Online: 21 June 2021 (14:22:35 CEST)
Pollination is the process by which pollen grains are exchanged in plant flowers to allow for fertilisation and production to take place. However, challenges occur when crops are grown under protected structures where there are minimal activities of natural pollination agents such as wind and animals which are responsible for transferring pollen grains from the anther to the stigma. Therefore, the study objective was to determine the effect on hand pollination on the yield of African horned cucumber grown under greenhouse and shade net environment. A factorial experiment with two factors (hand pollinated and non-hand pollinated/control) was conducted under two different growing environments (greenhouse and shade net). African horned cucumber plants were hand self-pollinated in the morning. Pollen were manually transferred with a hand using the new earbud from the male to the female flowers on the same plant (selfing). Results showed that hand pollinated African horned cucumber plants increased total biomass from 0.93 to 2.23 kg under greenhouse environment. Hand pollinated plants increased harvest index from 0.07 to 0.35 under shade net environment. It can thus, be deduced that hand pollination increases African horned cucumber yield in the greenhouse and shade net environments.
ARTICLE | doi:10.20944/preprints202101.0012.v1
Subject: Biology, Anatomy & Morphology Keywords: urban forestry; work analysis; residual biomass; pruning costs
Online: 4 January 2021 (11:24:12 CET)
The Italian Stone Pine (Pinus pinea L.) is one of the most employed ornamental trees in towns with Mediterranean climates. For example, in the city of Rome, Pinus is the most common genus, with more than 51,000 trees. This study investigates technical and economic features of maintenance operations of Stone Pines and evaluates the productivity and costs of the observed yards. Pruning and felling are the most frequent management operations of trees in towns and this study analyzes the features of these operations carried out in 14 work sites. The operations were carried out either with aerial platforms (19 trees) or ascending the crown by tree-climbing (6 trees). The operations were sampled with time studies (12 trees for pruning and 13 for felling). Work time was measured from the beginning of operations to the transport of the residual biomass to the collection and loading point, using centesimal stopwatches and video recording. The total residual biomass was weighed or assessed. Total observation time amounted to 63.1 hours. The evaluation of the costs of each work site considered the fixed and the variable costs and the costs for the labor force. A Multiple Linear Regression model (statistics: determination coefficient R2: 0.74, adjusted R2: 0.67, p-value < 0.001) which utilizes four regressors easily evaluable before the work, was adopted to predict the gross time of the operations. This paper can contribute to optimize trees maintenance methods in urban sites and to assess the potential residual wood biomass attainable from urban forestry maintenance in the city of Rome.
Subject: Earth Sciences, Atmospheric Science Keywords: biomass; biorefinery; permanent grasslands; Intensification; integral emission assessment
Online: 25 September 2020 (11:56:19 CEST)
Agricultural intensification is considered essential for meeting growing demand for food and biomass for energy and material purposes. Intensifying grasslands is a so-far under-represented although promising option, given their large land area and relatively low management levels. This study quantifies the bioenergy potential from intensifying temporary grasslands in Europe and the integral greenhouse gas emission effects in 2030. We first conduct a literature review of intensification options for European grasslands and then apply the environmental impact assessment model MITERRA-Europe to implement the key intensification option of using multi-species grass mixtures. The results show that 853 kha (or 8%) of temporary grassland could be made sustainably available for additional biomass production. This can be translated into a bioethanol potential of 23 PJ/yr and an emission mitigation potential of 5.8 Mt CO2-eq/yr (if conventional grass mixture from surplus temporary grassland is used for energy) or 72 PJ/yr and 4.0 Mt CO2-eq/yr (if surplus temporary grassland is used for grassy energy crops). Although the bioenergy potential is limited, the intensification measure’s key advantage is that it results in a better environmental performance of temporary grasslands. This makes it a key option for sustainably producing bioenergy in areas with high shares of temporary grasslands.
ARTICLE | doi:10.20944/preprints201910.0140.v1
Subject: Chemistry, Other Keywords: biomass; green chemistry; biopolymers; humins; epoxy resins; thermosets.
Online: 12 October 2019 (06:00:19 CEST)
The combination of eco-respectful epoxy compounds with the humins, a by-product of biomass chemical conversion technologies, allow the obtention of materials with high added value. In this work, we propose the chemical connection study of humins with two aliphatic diepoxides through the copolymerization reactions to synthesize sustainable bio-based thermosets. The mechanism insights for the crosslinking between the epoxides and humins was proposed considering the different functionalities of the humins structure. FT-IR spectroscopy, 1 D and 2 D NMR spectroscopy techniques were used to build the proposed mechanism. By these techniques, the principal chain connections and the reactivity of all the components were highlighted in the synthesized networks.
REVIEW | doi:10.20944/preprints201804.0204.v2
Subject: Life Sciences, Biotechnology Keywords: lignocellulosic biomass; laccases; peroxidases; green biochemical; acidophilic microbes
Online: 15 June 2018 (05:51:17 CEST)
The processing of fossil fuels is the major environmental issue today which should be lessen. Biomass is gaining much interest these days as an alternate to energy generation. Lignocellulosic biomass (cellulose, hemicellulose and lignin) is abundant and has been used for a variety of purposes. Among them, the lignin polymer having phenyl-propanoid subunits linked together through C-C bonds or ether linkages, can produce numerous chemicals. It can be depolymerized by microbial activity together with certain enzymes (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Natural organic acids production by fungi has many key roles in nature that are strictly dependent upon organic acid producing fungus type. Fungal enzymatic conversion of lignocellulosic is beneficial over other physiochemical processes. Laccases, the copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), the heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H2O2. Lignin depolymerization yields value-added compounds, the important ones are BTX (Benzene, Xylene and Toluene) and phenols as well as certain polymers like polyurethane and carbon fibers. Thus, this review will provide a concept that biological modifications of lignin using acidophilic microbes can generate certain value added and environment friendly chemicals.
ARTICLE | doi:10.20944/preprints201806.0043.v1
Subject: Earth Sciences, Atmospheric Science Keywords: saccharides; biomass burning; haze; source apportionment; bio-aerosol
Online: 4 June 2018 (12:47:58 CEST)
The characteristics of biogenic aerosols in urban area were explored by determining the composition, temporal distribution of saccharides in PM2.5 in Shanghai. The total saccharides showed a wide range of 15.2 ng/m3 to 1752.8 ng/m3, with the averaged concentrations were 169.8 ng/m3，300.5 ng/m3，288.4 ng/m3，688 ng/m3 in spring, summer, autumn, and winter, respectively. The concerned saccharides include anhydrosaccharides (levoglucosan and mannosan), which were higher in cold seasons due to the increased biomass burning, saccharide alcohols (mannitol, arabitol, sorbitol) and monosaccharides (fructose, glucose), which showed more abundant in warm seasons attributed to the biological emissions. By PMF analysis, four emission sources of saccharides were demonstrated, including biomass burning, fungal spores, soil suspension and plant pollens. Resolution of backward trajectory and fire points showed a process of high concentrations of levoglucosan. We found that concentrations of anhydrosaccharides showed relatively stable under different pollution levels while saccharide alcohols exhibited an obvious decrease, indicated that biomass burning was not the core reason of the heavy haze pollution, however, and high level PM2.5 pollution might inhibit effects of biological activities.
ARTICLE | doi:10.20944/preprints201801.0241.v1
Subject: Engineering, Energy & Fuel Technology Keywords: biomass; deacetylation; pretreatment; xylose; Pichia stipites; acetic acid
Online: 25 January 2018 (11:23:53 CET)
In order to produce bioethanol from yellow poplar sawdust without detoxification, deacetylation (mild alkali treatment) was performed with aqueous ammonia solution. To select the optimal conditions, deacetylation process was carried out using different conditions: NH4OH loading (2–10% (w/v)) and solid-to-liquid ratio (1:4–10) at 121 °C for 60 min. In order to assess the effectiveness of deacetylation, fractionation of deacetylated yellow poplar sawdust was performed using dilute acid (H2SO4, 0.5–2.0% (w/v)), reaction temperature (130–150 °C) and time (10–80 min). The toxicity-reduced hemicellulosic hydrolysates that were obtained through a two-step treatment at optimized conditions were fermented using Pichia stipitis for ethanol production, without any further detoxification. The maximum ethanol production was 4.84 g/L, corresponding to a theoretical ethanol yield of 82.52%, which is comparable to those of intentionally made hydrolyzates as controls.
ARTICLE | doi:10.20944/preprints201610.0088.v1
Online: 21 October 2016 (06:05:11 CEST)
Ecosystem physical structure, defined by the quantity and spatial distribution of biomass, influences a range of ecosystem functions. Remote sensing tools permit the non-destructive characterization of canopy and root features, potentially providing opportunities to link above- and belowground structure at fine spatial resolution in functionally meaningful ways. To test this possibility, we employed ground-based portable canopy lidar (PCL) and ground penetrating radar (GPR) along co-located transects in forested sites spanning multiple stages of ecosystem development and, consequently, of structural complexity. We examined canopy and root structural data for coherence at multiple spatial scales ≤ 10 m within each site using wavelet analysis. Forest sites varied substantially in vertical canopy and root structure, with leaf area index and root mass more evenly distributed by height and depth, respectively, as forests aged. In all sites, above- and belowground structure, characterized as mean maximum canopy height and root mass, exhibited significant coherence at a scale of 3.5-4 meters, and results suggest that the scale of coherence may increase with stand age. Our findings demonstrate that canopy and root structure are linked at characteristic spatial scales, which provides the basis to optimize scales of observation. Our study highlights the potential, and limitations, for fusing lidar and radar technologies to quantitatively couple above- and belowground ecosystem structure.
ARTICLE | doi:10.20944/preprints202206.0334.v1
Subject: Medicine & Pharmacology, Allergology Keywords: non-smoking COPD; phenotypes; air pollution; biomass; occupational exposure
Online: 24 June 2022 (08:18:34 CEST)
Chronic obstructive pulmonary disease (COPD) is strongly associated with tobacco smoking and it is the increasing cause of morbidity and mortality worldwide. The prevalence of COPD among never smokers varies widely across regions, areas, and nations. COPD in smokers has been extensively explored worldwide, however, COPD in non-smokers is under-explored and there is limited data available on non-smoking COPD. We determined the role of environmental pollution and biomass fuel exposure in COPD patients who were non-smokers. We evaluated the clinical profile of non-smokers with COPD in a retrospective observational study. 180 non-smoker COPD patients were selected from the year 2016-to 2018. We found that many patients with COPD are non-smokers and the incidence is higher among the rural population, suggesting that non-smoking COPD is evolving rapidly due to biomass smoke and other environmental pollutant exposures.
REVIEW | doi:10.20944/preprints202108.0463.v1
Online: 24 August 2021 (10:33:03 CEST)
This review reports the available technologies for the flexible utilization of biomass towards negative CO2 emissions and addresses the possibility to couple biogas production plants with the electrical grid converting excess electrical energy into storable chemical molecules. This changed mind-set towards biomass utilization can lead readily to the implementation of negative CO2 emission along the entire bioenergy supply chain without limiting the potential for Power-to-X applications. First, the technologies for direct conversion of waste and wood into gaseous energy carriers are screened, to highlight the potential for the production of renewable fuels. Second, the processes for the removal of CO2 from biogenic gas streams are analysed in terms of technological performance, cost and further potential for the CO2 recovered. These technologies are the key to pre-combustion CO2 capture and negative emissions. Third, the possibility of coupling biomass conversion and synthetic fuels production is explored, providing an overview on the technical maturity of the various energy storage processes. The flexible use of biomass can be an essential part of the future CO2-free energy systems, as it can directly provide energy carriers all around the year and also large quantities of climate-neutral carbon for the production of synthetic fuels with renewable energy. In turn, when no additional renewable electricity is available, the CO2 by-product from biofuel synthesis can be used for the negative emissions. This opens the way to an efficient strategy for the seasonal storage of electrical energy, realizing a carbon-neutral energy system coupled with the development of carbon-negative energy strategy.
ARTICLE | doi:10.20944/preprints202102.0568.v1
Subject: Materials Science, Biomaterials Keywords: Biomass fractionation; formic acid; levulinic acid; lignin; maritime pine
Online: 25 February 2021 (09:56:17 CET)
Lignocellulosic biomass fractionation is typically performed using methods that are somehow harsh to the environment, such as in the case of the kraft pulping. In recent years, the development of new sustainable and environmentally friendly alternatives has grown significantly. Among the developed systems, bio-based solvents emerge as promising alternatives for biomass processing. Therefore, in the present work, the bio-based and renewable chemicals, levulinic acid (LA) and formic acid (FA), were combined to fractionate lignocellulosic waste (i.e., Maritime pine sawdust) and isolate lignin. Different parameters, such as LA/FA ratio, temperature, and extraction time, were optimized to boost the yield and purity of extracted lignin. The LA/FA ratio was found to be crucial regarding the superior lignin extraction from the waste biomass. Moreover, the increase in temperature and extraction time enhances the amount of extracted residue but compromises the lignin purity and reduces its molecular weight. The electron microscopy images revealed that biomass samples suffer significant structural and morphological changes, which further suggests the suitability of the new developed bio-fractionation process. Same was concluded by the FTIR analysis, in which no remaining lignin was detected in the cellulose-rich fraction. Overall, the novel combination of bio-sourced FA and LA has shown to be a very promising system for lignin extraction of high purity from biomass waste, thus contributing to extend the opportunities of lignin manipulation and valorisation into novel added-value biomaterials.
ARTICLE | doi:10.20944/preprints202101.0419.v1
Subject: Engineering, Automotive Engineering Keywords: Hydrolysate; Chlorella sorokiniana; lipid; biomass productivity; nutrient amended media.
Online: 21 January 2021 (12:39:53 CET)
Hydrolysate prepared from water hyacinth biomass, containing a considerable amount of solubilised carbohydrate and nutrients, was utilised as a medium for the cultivation of two strains of Chlorella sorokiniana. These strains were isolated from an oxidation pond using two different media, i.e., BG-11 and Knop's media maintained at pH-9. Different light intensities, light-dark cycles, and various concentrations of external carbon sources (monosaccharides and inorganic carbon) were used to optimise the microalgal growth. It was observed that in the presence of organic carbon (glucose), biomass productivity increased significantly (~300 mgL-1day-1) as compared to that in the presence of only inorganic carbon (~100 mgL-1day-1). For the accumulation of stress products (lipids and carbohydrates), the microalgal strains were transferred to nutrient-amended media (N-amended and P-amended). The combined effects of glucose, inorganic carbon, and a 12h:12h light-dark cycle proved to be optimum for biomass productivity. For Chlorella sp. isolated from BG-11, maximum carbohydrate content (22%) was found in the P-amended medium, whereas high lipid content (17.3%) was estimated in the N-amended medium. However, for Chlorella sp. isolated from Knop's medium, both the lipid (17%) and carbohydrate accumulation (12.3%) were found maximum in the N- amended medium. Kinetic modelling of the lipid profile revealed that kinetic coefficients obtained for strain isolated from BG-11 media were statistically significant from each other.
ARTICLE | doi:10.20944/preprints202008.0224.v1
Subject: Life Sciences, Other Keywords: biomass allocation; drought; irrigation; leaf anatomy; mRNA level; proline
Online: 9 August 2020 (21:53:38 CEST)
Recent climatic changes have resulted in an increased frequency and prolonged periods of drought and strained water resources affecting plant production. We explored the possibility of reducing irrigation in a container nursery and studied the growth response of seedlings of economically important forest trees: broadleaf deciduous angiosperms Fagus sylvatica, Quercus petraea and evergreen conifers Abies alba and Pinus sylvestris. We also studied markers of water stress including modifications of biomass allocation, leaf anatomy, proline accumulation and expression of selected genes. Growth of the broadleaved deciduous species was more sensitive to the reduced water supply than that of conifers. Remarkably, growth of the shade tolerant Abies was not affected. Adjustment of biomass allocations was strongest in P. sylvestris, with a remarkable increase in allocation to roots. In response to water deficit both deciduous species accumulated proline in leaves and produced leaves with shorter palisade cells, reduced vascular tissues and smaller conduit diameters, but not conifers. Relative transcript abundance of a gene encoding a Zn-finger protein in Q. petraea and a gene encoding a pore calcium channel protein 1 in A. alba increased as water deficit increased. These findings suggest that in container nursery, the genetic selection can be initiated by water deficit. Our study shows major differences between functional groups in response to irrigation, with seedlings of evergreen conifers having higher tolerance than the deciduous species. This suggests that major water savings could be achieved by adjusting irrigation regime to functional group or species requirements.
ARTICLE | doi:10.20944/preprints202007.0750.v1
Subject: Earth Sciences, Geoinformatics Keywords: Amazon; recovery time; aboveground biomass; climate change; 3-PG
Online: 31 July 2020 (13:51:03 CEST)
In the last decades droughts, deforestation and wildfires have become recurring phenomena that have affected both human activities and natural ecosystems in Amazonia. The time an ecosystem requires to recover from carbon losses is a crucial metric to evaluate disturbance impacts on forests. However, the factors influencing and controlling the recovery time and its spatiotemporal patterns at the regional scale are still poorly understood. In this study, we combined forest growth model, remote sensing and field plots, to map Amazonia-wide (300-ha resolution) impact and recovery time of aboveground biomass (AGB) after drought, fire and a combination of logging and fire. Our simulated results indicate that AGB decreases by 4%, 19% and 46% in forests disturbed by drought, fire and logging + fire, respectively, with an average AGB recovery time of 27 years for drought, 44 years for burned and 63 years for logged + burned areas and with maximum values reaching 184 years in areas of high fire intensity. Our findings provide two major insights in the spatial and temporal patterns of drought and wildfire in the Amazon: 1) the recovery time of the forests takes longer in the southeastern part of the basin, and, 2) as droughts and wildfires become more frequent – since the intervals between the disturbances is getting shorter than forest regeneration – potentially causing a long-lasting damage in these fragile ecosystems and a permanent degradation.
Subject: Biology, Agricultural Sciences & Agronomy Keywords: wheat; UAV image; color index; texture feature index; biomass
Online: 26 December 2019 (12:27:49 CET)
In order to realize rapid and nondestructive monitoring of wheat biomass in field, field experiments based on different densities, nitrogen fertilizer and variety treatments were studied. RGB images of wheat in the main growth stage were obtained by UAV, and wheat color and texture feature indices were obtained by image processing, and wheat biomass was obtained by field sampling in the same period. Then the relationship between different color and texture feature indices and wheat biomass was analyzed to select the color and texture feature index suitable for wheat biomass estimation. The results showed that there was a high correlation between image color index and wheat biomass in different stages, and most of them reached a very significant correlation level. However, the correlation between image texture feature index and wheat biomass was poor, only a few indexes reached significant or extremely significant correlation level. Based on the above results, the color indices with the highest correlation to wheat biomass or the combining indices of color and texture feature in different growth stage were used to construct estimation model of wheat biomass. The models were validated using independently measured biomass data, and the correlation between simulated and measured values reached the significant level, RMSE were smaller. This indicated that the estimated results by the models were reliable and accurate. It also showed that the estimation models of wheat biomass combined with color and texture feature indices of UAV image were better than the single color index models. The results would provide a new method for real-time monitoring of wheat field growth and biomass estimation.
ARTICLE | doi:10.20944/preprints201911.0108.v1
Subject: Earth Sciences, Environmental Sciences Keywords: microalgae; cyanobacteria; biomass composition; culture optimization; growth on wastewaters
Online: 10 November 2019 (10:56:59 CET)
The purpose of this work is to define optimal growth conditions for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on algae growth: i.e., inoculum:culture medium ratio, light:darkness photoperiod and type of culture medium, including both synthetic media and wastewaters. The results showed that the initial inoculum volume did not affect the amount of biomass at the end of the growth (14 days), whereas an excess (18 h) or defect (6 h) in the number of hours of light is determinant for its development. The contribution of nutrients from different culture media modified the growth of the different species. A. maxima was favoured in seawater enriched with Guillard's F/2 as well as C. vulgaris and N. gaditana but in fresh water medium. I. galbana had the greatest growth in the marine environment enriched with Walne’s media. Nitrate was the limiting growth reagent at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalgae species.
ARTICLE | doi:10.20944/preprints201909.0108.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: biomass, Fusarium head blight, real-time PCR, trichothecenes, zearalenone
Online: 10 September 2019 (11:24:51 CEST)
The aim of the study was to determine the presence Fusarium species and mycotoxins in winter wheat grain in Poland. Grain samples from different locations in Poland in 2009 and 2010 were analysed for the content of biomass of Fusarium species and mycotoxins. In 2009 biomass of F. graminearum and F. poae was present in all samples, F. culmorum in 82% of samples, F. avenaceum in 55% of samples. F. sporotrichioides, F. tricinctum and F. equiseti were found only in individual samples. F. langsethiae was not detected. In 2010, five Fusarium species were detected with the exception of F. sporotrichioides. The highest content of biomass was found for F. graminearum followed by F. avenaceum, F. poae and F. langsethiae. The amount of F. culmorum biomass was very low. The most frequently occurring species was F. poae and F. graminearum. In 2009, deoxynivalenol was detected in all samples. In 2010, the average content of deoxynivalenol was lower than in 2009. Nivalenol was detected at very low concentration in both years. Significant correlations between content of F. graminearum biomass and deoxynivalenol concentration in grain and between content of F. poae biomass and nivalenol concentration in grain in 2009 were found. The most important finding of this study was that main Fusarium species infecting wheat kernels in Poland in both years was F. graminearum. The amount of biomass of F. graminearum was the highest in both years. It was present in the most samples. The other frequently detected species was F. poae, which in 2010 appeared in more samples than F. graminearum. However, the amount of F. poae biomass was lower. F. culmorum, species that was previously dominating as wheat pathogen in Poland, was found less frequently than F. graminearum. The amount of biomass of this species was the lowest in 2010.
ARTICLE | doi:10.20944/preprints201907.0292.v1
Subject: Earth Sciences, Space Science Keywords: nitrate; Mars; Atacama Desert; sedimentation rates; biomass preservation; extremophiles
Online: 25 July 2019 (11:52:52 CEST)
Nitrate is rich in Mars sediments owing to long-term atmospheric photolysis, oxidation, and deposition coupled with a lack of leaching via rainfall. The Atacama Desert in Chile, which is similarly dry and rich in nitrate deposits, is used as a Mars analog in this study to explore the potential effects of high nitrate levels on microbial growth. Seven study sites sampled across an aridity gradient in the Atacama Desert were categorized into 3 clusters – hyperarid, intermediate, and arid sites, as defined by major elements in the regolith, associated biomass, and precipitation. Intriguingly, the distribution of nitrate concentrations in the shallow subsurface suggests that the buildup of nitrate is not solely controlled by precipitation. Correlations of nitrate with SiO2/Al2O3 and grain sizes suggest that sedimentation rates are also important in controlling nitrate distribution. At arid sites receiving more than 10 mm/yr precipitation, rainfall shows a stronger impact on biomass than nitrate does. However, high nitrate to organic carbon ratios are generally beneficial to N assimilation as evidenced both by soil geochemistry and enriched culturing experiments. This study suggests that even in the absence of precipitation on contemporary Mars, the nitrate levels are sufficiently high to benefit potentially extant Martian microorganisms.
ARTICLE | doi:10.20944/preprints201902.0037.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Biomass, valorisation, ionic liquid, crystallinity, enzymatic hydrolysis, pre-treatment
Online: 4 February 2019 (13:57:18 CET)
Ionic liquids have been recognised as interesting solvents applicable in the efficient lignocellulosic biomass valorisation, especially in the biomass fractionation into individual polymeric components or direct hydrolysis some of biomass fractions. Considering the chemical character of ionic liquids, two different approaches, paved the way for a fractionation of biomass. The first strategy integrated a pre-treatment, hydrolysis and conversion of biomass through the employment of hydrogen-bond acidic 1-ethyl-3-methyimidazolim hydrogen sulfate ionic liquid. The second one relied on the use of a three-step fractionation process with hydrogen-bond basic 1-ethyl-3-methylimidazolium acetate to produce high purity cellulose, hemicellulose and lignin fractions. The proposed approaches were scrutinised for wheat straw and eucalyptus residues. Those different biomasses allowed understanding that enzymatic hydrolysis yields are dependent on the crystallinity of pre-treated biomass. The use of acetate based ionic liquid allowed to change crystalline cellulose I to cellulose II and consequently enhanced glucan to glucose yield to 93.14.1 mol% and 82.91.2 mol% for wheat straw and eucalyptus, respectively. Whereas for hydrogen sulfate ionic liquid, the same enzymatic hydrolysis yields were 61.6 0.2 mol% for wheat straw and only 7.90.3 mol% for eucalyptus residues. These results demonstrate the importance of either ionic liquid character or biomass type on the efficient biomass processing.
COMMUNICATION | doi:10.20944/preprints201811.0380.v1
Subject: Engineering, Energy & Fuel Technology Keywords: bio-oil; biomass conversion; carbide catalyst; ketonization; doped carbides
Online: 16 November 2018 (07:10:50 CET)
Carboxylic acids such as acetic acid and propionic acid have been investigated as representative components for fast pyrolysis (FP) bio-oil upgrading. Selective catalytic conversion of carboxylic acids can enhance bio-refinery processing economics through catalyst preservation and process intensification. Various metal-doped molybdenum carbide bead catalysts have been synthesized and developed in this work. Our aim is to enable selective conversion of carboxylic acids. In the case of acetic acid conversion, calcium doped Mo2C beads offer the highest yield of acetone ~96% at 450 °C among undoped and Ca or Ni doped catalysts. By comparing hot gas filter with and without Ca-Mo2C catalyst tested with real FP vapors, the former showed a 36.7% reduction of acetic acid, a 37.5% reduction of small ketones in aqueous phase, and a ~50% reduction of methoxies (methoxy phenols and methoxy aromatics) in organic phase. The conversion resulted in the formation of more long chain chemicals in the organic phase, which are more amendable for downstream upgrading.
ARTICLE | doi:10.20944/preprints201810.0426.v1
Subject: Biology, Forestry Keywords: acacia species; allometric equation; above ground biomass; carbon stock
Online: 18 October 2018 (15:58:15 CEST)
Allometric equations are used to estimate accurate biomass and carbon stock of forests. However, in Ethiopia only few allometric equations as compared to its floral diversity and species-specific allometric equations for Acacia species are still not developed in Ethiopia. The numbers of tree marked for sampling are Fifty-four (54) using preferential sampling. Diameter at breast height, wood density and tree height were collected as independent variables to predict species specific dry biomass of Acacia species. The new species-specific allometric models have been performed using linear regression analysis in the R software. The Above ground biomass (AGB) have been validated using quantitative statically using the pantropic model. Six candidate models have been developed for each species and four best models for each species of dry biomass was selected based on goodness-of-fit statistics and equation performance analysis of the candidate models. The best model for predicting above ground biomass for Acacia seyal is 0.20636*((DBH2)Hρ) 0.53167, for Acacia polyacantha is 7.26982((DBH)2Hρ)0.21750, for Acacia ethibcia is 29.01898*((DBH)2Hρ)0.21518 and for Acacia toritolis is 3.82427*((DBH)2Hρ)0.16748. The selected models are the best performing (P> 0.01) and higher adjusted R2 (>80%) and has lower Akaike’s Information Criteria (AIC) and residual standard error (RSE) values as comparing the rest of the model. The validation of new developed biomass model using Tukey test indicated that significant variation of mean biomass (P<0.05) between the new developed model and the generalized model. The statistics model performance analysis of Nash-Sutcliffe efficiency (NSE) value is approaching to one, indicating that the new developed model has better performance model as compared with generalized model. Moreover, the percent bias of the new developed models is close to zero which indicates that the site-specific biomass models have more accurate estimator and the generalized biomass models have overestimated biomass for the four Acacia species.
ARTICLE | doi:10.20944/preprints201805.0402.v1
Subject: Chemistry, Applied Chemistry Keywords: heterogeneous catalysis; transfer hydrogenation; biomass conversion; biofuels; catalytic materials
Online: 28 May 2018 (12:27:29 CEST)
Catalytic upgrading of bio-based platform molecules is one of promising approaches for biomass valorization. However, most solid catalysts are thermally and/or chemically unstable and difficult to prepare. In this study, a stable organic phosphonate-hafnium solid catalyst (PPOA-Hf) was synthesized, and acid-base bifunctional sites were found to play a cooperative role in the cascade transfer hydrogenation and cyclization of ethyl levulinate (EL) to γ-valerolactone (GVL). Under relatively mild reaction conditions of 160 ºC for 6 h, EL was completely converted to GVL in a good yield of 85%. The apparent activation energy was calculated to be 53 kJ/mol, which was lower than other solid catalysts for the same reaction. In addition, the PPOA-Hf solid catalyst did not significantly decrease its activity after five recycles, and no evident leaching of Hf was observed, indicating its high stability and potential practical application.
ARTICLE | doi:10.20944/preprints201804.0270.v1
Subject: Materials Science, Polymers & Plastics Keywords: Renewable resources; Lignocellulosic Biomass; Polymerization; Reaction mechanisms; Furfuryl alcohol
Online: 20 April 2018 (14:19:30 CEST)
Furfuryl alcohol (FA) is a biobased monomer derived from lignocellulosic biomass. The present work describes its polymerization in presence of protic polar solvents, i.e. water or isopropyl alcohol (IPA), using maleic anhydride (MA) as acidic initiator. The polymerization was followed from the liquid to the rubbery state by combining DSC and DMA data. In the liquid state, IPA disrupts the expected reactions during all the FA polymerization due to a stabilization of the furfuryl carbenium center. This causes the initiation of the polymerization at higher temperature, which is also reflected by higher activation energy. In water system, the MA opening allows to start the reaction at lower temperature. A higher pre-exponential factor value is obtained in that case. The DMA study of final branching reaction occurring in the rubbery state has highlighted continuous increase of elastic modulus until 290 °C. This increasing tendency of modulus was exploited to obtain activation energy dependences (Eα) of FA polymerization in the rubbery state.
ARTICLE | doi:10.20944/preprints201712.0177.v1
Subject: Materials Science, Polymers & Plastics Keywords: bamboo biomass; biodegradable composites; pull-out; surface treatments; mercerization
Online: 25 December 2017 (10:12:19 CET)
In this work, the apparent shear strength at the interface between a bamboo fiber and the surrounding poly(lactic acid) (PLA) matrix is quantified. A method for processing pull-out test samples within a controlled embedded length is proposed and the details of the test procedure are presented, along with a critical discussion of the results. Two series of samples are considered: untreated and mercerized bamboo fibers from the same batch, embedded in the same polyester matrix. Electron and optical microscopy are used to observe the fiber-matrix interface before and after the test, and to identify the failure mode of each sample, especially as regards the occurrence of fibrillation in the fiber bundles. The values of apparent interfacial shear strength are calculated only for regular fibers successfully pulled out from the matrix, and reported with their statistical variations. Mercerization, whose efficiency was proven by Fourier Transform InfraRed (FTIR) spectroscopy, did not appear though to improve the quality of the interface (τapp = 7.0 ± 3.1 MPa for untreated fibers and τapp = 5.3 ± 2.4 MPa for treated fibers).
ARTICLE | doi:10.20944/preprints201707.0058.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Albedo; Biomass; Land cover; Regional heat capacity; Surface Temperature
Online: 20 July 2017 (13:35:01 CEST)
Regional heat capacity change is calculated from the ratio between the addition or subtraction of heat (ΔQ) with the increase or decrease in temperature (ΔT) region. The purpose of this study is to calculate the regional heat capacity change due to the changes of land cover composition with forest, shrubs, oil palm plantation and bare soil using Landsat-5 TM satellite data on 1994, 2000 and 2010. Total area that used on this study is 12971 ha. In 1994-2000, 4 % of forest area and 2% shrubs were increased, followed by additional of biomass forest 4.01 tons/ha and 2.83 tons/ha for shrubs. The increased of forest area and biomass (tons/ha) caused by forest and shrubs growth processing towards climax that added the canopy volume. So that, the regional heat capacity in 1994 amounted 19384 MJCo-1 increased to 19929 MJCo-1 in 2000. Data observation for 2000-2010 showed that forest area decreased by 66% due to forest’s clearing into oil palm plantations (47%), shrubs (8%) and bare soil (11%). But, plant’s biomass continue to increased, i.e 1.48 ton/ha for forest, 2.73 tons/ha for shrubs and 4.63 tons/ha for bare soil. Before 2000, there was no land cover by oil palm plantations, so the increasing rate from this land was the biggest than the three other lands, amounting to 122.29 tons/ha. Decreasing in the percentage of forest area does not cause a decrease in the heat capacity of the region. Intensive maintenance on oil plam plantation such as water management, fertilizer and planting space made it biomass productivity and ability to save the heat is greater than the forest. As the result, in 2010 regional heat capacity increased to 22508 MJCo-1.
ARTICLE | doi:10.20944/preprints201702.0035.v1
Subject: Earth Sciences, Environmental Sciences Keywords: sewage sludge; biomass fraction; sewage sludge incinerator; GHG emission
Online: 13 February 2017 (09:11:27 CET)
According to the IPCC guidelines, CO2 emissions from biomass should be excluded from the entire amount of CO2 emissions when calculating CO2 emissions and should be separately reported due to the “carbon neutrality.” Sewage sludge is one of the representative biomass fuels. And it is mixed with fossil fuels in terms of greenhouse gas reduction or is used as fuel to replace fossil fuels by itself. According to the results of this study, biomass contents of both the sewage sludge and the sewage sludge incineration exhaust gases did not amount to 100%. At present, in many countries(South Korea, Japan, and Germany), when calculating greenhouse gas emissions from sewage sludge incinerator, all CO2 emissions from sewage sludge are judged to be biomass and only those greenhouse gas emissions that correspond to Non-CO2 gases are calculated as greenhouse gas emissions. However, since, according our results, the content of sewage sludge is not 100% biomass, if CO2 emissions are excluded according to the existing greenhouse gas emission calculation method, the amount of emissions may be underestimated. Therefore, to accurately calculate greenhouse gas emissions from sewage sludge incinerator, CO2 emissions should be calculated in consideration of the fossil carbon contents of sewage sludge.
REVIEW | doi:10.20944/preprints202301.0361.v1
Subject: Biology, Other Keywords: Biomass valorization; Microalgae; Nutrient recovery; Purple phototrophic bacteria; Swine manure
Online: 19 January 2023 (12:20:24 CET)
Piggery wastewater (PWW) is characterized by its high concentrations of organic matter and ammonium, and by their odour nuisance. Traditionally, PWW has been treated in open anaerobic lagoons, anaerobic digesters and activated sludge systems, which exhibit high greenhouse gas emissions, a limited nutrients removal and a high energy consumption, respectively. Photosyn-thetic microorganisms can support a sustainable PWW treatment in engineered photobioreactors at low operating costs and with an efficient recovery of carbon, nitrogen and phosphorous. These microorganisms are capable of absorbing solar irradiation through the photosynthesis process to obtain energy, which is used for their growth and associated carbon and nutrients assimilation. Purple phototrophic bacteria (PPB) represent the photosynthetic microorganisms with the most versatile metabolism in nature, while microalgae are the most studied photosynthetic microor-ganisms in recent years. This review describes the fundamentals, symmetry and asymmetry of PWW treatment using photosynthetic microorganisms such as PPB and microalgae. The main photobioreactor configurations along with the potential of PPB and microalgae biomass valori-zation strategies are also discussed.
ARTICLE | doi:10.20944/preprints202203.0158.v1
Subject: Earth Sciences, Atmospheric Science Keywords: air quality management; biomass burning; carbon; PCA; PM0.1; trace elements
Online: 11 March 2022 (03:02:33 CET)
The concentration of total suspended particles (TSP) and nanoparticles (PM0.1) over Hat Yai city, Songkhla province, southern Thailand was measured in 2019. Organic carbon (OC) and elemental carbon (EC) were evaluated by carbon aerosol analyzer (IMPROVE-TOR) method. Thirteen trace elements including Al, Ba, K, Cu, Cr, Fe, Mg, Mn, Na, Ni, Ti, Pb, and Zn were evaluated by ICP-OES. Annual average TSP and PM0.1 mass concentrations were determined to be 58.3 ± 7.8 and 10.4 ± 1.2 µg/m3, respectively. The highest levels of PM occurred in the wet season with the corresponding values for the dry seasons being lower. The annual average OC/EC ratio ranged from 3.8 - 4.2 (TSP) and 2.5 - 2.7 (PM0.1). The char to soot ratios were constantly less than 1.0 for both TSP and PM0.1, indicating that land transportation is the main emission source. A principal component analysis (PCA) revealed that road transportation, industry, and biomass burning are the key sources of these particles. However, PM arising from Indonesian peatland fires causes an increase in the carbon and trace element concentrations in southern Thailand. The findings make useful information for air quality management and strategies for controlling this problem, based on a source apportionment analysis.
REVIEW | doi:10.20944/preprints202108.0575.v1
Subject: Earth Sciences, Atmospheric Science Keywords: Health Risk; Ultrafine Particles; Nanoparticles; South East Asia; Biomass burning
Online: 31 August 2021 (12:57:15 CEST)
PM0.1 (particles diameter ≤ 0.1 µm), nanoparticles (NPs), and ultrafine particles (UFPs), were interchangeably used in the scientific communities. PM0.1 originated from both natural and human sources. However, investigations of PM0.1 and its effects on the environment, visibility, and human health risk to understand the levels of air pollution, sources, and impacts in South East Asia (SEA) countries continue to be lacking. The concentration of PM0.1 in most SEA countries are much worse than those in western countries environment. A further motivation of this reviewed article is to provide a critical synthesis of the current knowledge and study of ambient PM0.1 in SEA cities. The main influence of characteristics of PM0.1 appears to be local sources including biomass burning and motor vehicles. Continuous monitoring of PM0.1 in terms of both mass and number concentration should be further understood. A critical review is of great importance to facilitating air pollution control policies and predicting the behavior of PM0.1 in SEA.
ARTICLE | doi:10.20944/preprints202105.0542.v1
Subject: Engineering, Automotive Engineering Keywords: hybridization; single-flash; geothermal; biomass; sCO2 cycle; olive residue; flexibility
Online: 24 May 2021 (08:48:56 CEST)
This study investigates the hybridization scenario of a single flash geothermal power plant with a biomass driven sCO2-steam Rankine combined cycle where a solid local biomass source, olive residue, is used as a fuel. The hybrid power plant is modeled using the simulation software EB-SILON®Professional. A topping sCO2 cycle is specifically chosen for its potential for flexible elec-tricity generation. A synergy between the topping sCO2 and bottoming steam Rankine cycles is achieved by a good temperature match between the coupling heat exchanger where the waste heat from the topping cycle is utilized in the bottoming cycle. The high temperature heat addition problem common sCO2 cycles is also eliminated by utilizing the heat in the flue gas in the bottoming cycle. Combined cycle thermal efficiency and biomass to electricity conversion efficiency of 24.9% and 22.4% are achieved, respectively. The corresponding fuel consumption of the hybridized plant is found as 2.2 kg/s.
ARTICLE | doi:10.20944/preprints202012.0444.v1
Subject: Biology, Anatomy & Morphology Keywords: novel rumen yeast; screening; isolation; biomass of yeast; cellulase enzyme
Online: 18 December 2020 (07:26:28 CET)
We hypothesized that rumen fluid with yeast producing cellulase enzyme can occur and also produces a high biomass compared to S. cerevisiae. Therefore, the aim of this study was to screen and isolate yeast from rumen fluids with an experimental design method. We optimized a fermentation medium containing sugarcane molasses as a carbon source and urea as a nitrogen source to measure the efficiency of biomass production and cellulase activity. Two fistulated-crossbred Holstein Friesian steers, averaging 350 ± 20 kg body weight, were used to screen and isolate ruminal yeast. The two experiments were designed. A 12 × 3 × 3 factorial was used in a completely randomized design to determine biomass and carboxymethyl cellulase activity. Factor A was isolated yeasts and S. cerevisiae. Factor B was sugarcane molasses (M) concentration. Factor C was urea (U) concentration. Potential yeast was selected for identified and analyzed as a 4 × 3 factorial use in a completely randomized design including. Factor A was incubation times. Factor B was isolated yeast strains including code H-KKU20 (as P. kudriavzevii-KKU20), I-KKU20 (C. tropicalis-KKU20), and C-KKU20 (as Galactomyces sp.-KKU20). Isolation was under aerobic conditions, resulting in a total of 11 different colonies. We noted two appearances of colonies including, asymmetric colonies of isolated yeast (indicated as A, B, C, E, and J) and ovoid colonies (coded as D, F, G, H, I, and K). The highest biomass was observed in three yeasts including codes H, I, and C-KKU20 when inoculated in 25% molasses with 1% urea (M25+U1) (p <0.01). The highest CMCase activity was observed in yeast code H-KKU20 when inoculated in all media solutions (p <0.01). Ruminal yeasts strains H-KKU20, I-KKU20, and C-KKU20 were selected for their ability to produce biomass and their CMCase enzyme synthesis. Identification of isolates H-KKU20 and I-KKU20 revealed that those isolates belonged to Pichia kudriavzevii-KKU20 and Candida tropicalis-KKU20, while C-KKU20 was identified as Galactomyces sp.-KKU20. Two strains provided maximum cell growth: P. kudriavzevii-KKU20 (9.78 and 10.02 Log cell/ml) and C. tropicalis-KKU20 (9.53 and 9.6 Log cells/ml) at 60 and 72 h of incubation time, respectively. The highest ethanol production was observed in S. cerevisiae: 76.4, 77.8, 78.5, and 78.6 g/L at 36, 48, 60, and 72 h of incubation time, respectively (p <0.01). The P. kudriavzevii-KKU20 yielded the least reducing sugar about 30.6 and 29.8 g/L at 60 and 72 h of incubation time, respectively. It could be concluded that screening and isolating yeast from rumen fluids resulted in 11 different characteristics of yeasts. The first novel yeasts discovered in the rumen fluid of cattle were Pichia kudriavzevii-KKU20, Candida tropicalis-KKU20, and Galactomyces sp.- KKU20. P. kudriavzevii-KKU20 had higher results than the other yeasts in terms of biomass production, cellulase enzyme activity, and cell number.
REVIEW | doi:10.20944/preprints202011.0019.v1
Subject: Biology, Anatomy & Morphology Keywords: aging; biomass conversion; C. elegans; reproductive death; semelparity; senescent pathology
Online: 2 November 2020 (10:45:56 CET)
In some species of salmon, reproductive maturity triggers the development of massive pathology resulting from reproductive effort, leading to rapid post-reproductive death. Such reproductive death, which occurs in many semelparous organisms (with a single bout of reproduction), can be prevented by blocking reproductive maturation, and this can increase lifespan dramatically. Reproductive death is often viewed as distinct from senescence in iteroparous organisms (with multiple bouts of reproduction) such as humans. Here we review the evidence that reproductive death occurs in C. elegans and discuss what this means for its use as a model organism to study aging. Inhibiting insulin/IGF-1 signaling and germline removal suppresses reproductive death and greatly extends lifespan in C. elegans, but can also extend lifespan to a small extent in iteroparous organisms. We argue that mechanisms of senescence operative in reproductive death exist in a less catastrophic form in iteroparous organisms, particularly those involving costly resource reallocation, and exhibiting endocrine-regulated plasticity. Thus, mechanisms of senescence in semelparous organisms (including plants) and iteroparous ones form an etiological continuum. Therefore understanding mechanisms of reproductive death in C. elegans can teach us about some mechanisms of senescence that are operative in iteroparous organisms.
ARTICLE | doi:10.20944/preprints201906.0126.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Biorenewable energy; pruning biomass; torrefaction; biochar; fuel properties; Oxytree; model
Online: 13 June 2019 (13:34:42 CEST)
Biowaste generated in the process of Oxytree cultivation and logging represents a potential source of energy. Torrefaction (a.k.a. low-temperature pyrolysis) is one of the methods proposed for the valorization of woody biomass. Still, energy is required for the torrefaction process during which the raw biomass becomes biochar with fuel properties similar to lignite coal. In this work, models describing the influence of torrefaction temperature and residence time on the resulting fuel properties (mass and energy yields, energy densification ratio, organic matter and ash content, combustible parts, lower and higher heating values, CHONS content, H:C and O:C ratios) were proposed according to the Akaike criterion. The degree of the models’ parameters matching the raw data expressed as the determination coefficient (R2) ranged from 0.52 to 0.92. Each model parameter was statistically significant (p<0.05). Estimations of the value and quantity of the produced biochar from 1 Mg of biomass residues were made based on two models and a set of simple assumptions. The value of torrefied biochar (€123.4·Mg-1) was estimated based on the price of commercially available coal fuel and its lower heating value (LHV) for biomass moisture content of 50%, torrefaction for 20 min at 200 °C. This research could be useful to inform techno-economic analyses and decision-making process pertaining to the valorization of pruned biomass residues.
ARTICLE | doi:10.20944/preprints201810.0112.v1
Subject: Social Sciences, Economics Keywords: woody biomass; Northern Great Plains; farmers and ranchers; focus groups
Online: 6 October 2018 (08:56:18 CEST)
Bioenergy produced from perennial feedstocks such as woody biomass could serve as an opportunity to strengthen local and regional economies and also jointly produce various environmental services. In order to assess the potential for biomass- based bioenergy, it’s essential to characterize the interest that potential biomass suppliers have in such an endeavor. In the U.S. Great Plains region, this largely means assessing relevant perceptions of farmers and ranchers. We conducted a series of farmer and rancher oriented focus groups in North Dakota, South Dakota, Nebraska and Kansas to qualitatively explore opinions about the role that trees can play in agriculture and interest in woody biomass systems within existing Northern Great Plains (NGP) farms and ranches. Our findings suggest that farmer and ranchers generally value the role that trees, or tree-based practices like windbreaks can play in agriculture particularly on marginal farmland in terms of conservation or crop protection. Yet relative to the potential of trees as a biomass crop there is a distinct lack of knowledge and skepticism. Farmers and ranchers also noted variable degrees of risk concern and uncertainty regarding investing in tree-based systems, as well as a number of perceived external market related constraints to integrating trees within their managed systems. Most of the participants recognized that if biomass production or an increase in tree planting and management in general were to expand in the NGP region, government programs would likely be required to provide much needed technical guidance and financial incentives. As the NGP regional bioeconomy continues to emerge and expand, private and public investment relative to niche bioenergy feedstocks such as woody biomass should address the type of information needs that farmers and ranchers have relative to integrating biomass production into existing farm and ranch systems.
ARTICLE | doi:10.20944/preprints201712.0086.v1
Subject: Materials Science, Biomaterials Keywords: activated carbon; barley husk; corn cob; agave leaves; biomass; thermogravimetry
Online: 14 December 2017 (07:46:00 CET)
Biomass is a promising alternative and renewable energy source that can be transformed into other value-added products such as activated carbon. In this research, barley husk, corn cob and Agave salmiana leaves were characterized to determine their chemical composition and morphology to evaluate their potentiality as precursors of activated carbons. Based on the main composition results obtained, the biomass samples have suitable chemical and physical characteristics to be considered as good precursors of activated carbons, such as carbon contents greater than 40%, ash content less than 10%, moisture content less than 30%, high volatile contents with values from 75 to 80% and a porous and fibrous morphology. The results indicate that the main compositions in the biomass were cellulose and lignin. The cellulose content was more than lignin (15–26%) for the residues selected. Specifically, a-cellulose contents with values from 52% to 79%, β-cellulose contents of 13–44%, γ-cellulose contents less than 11%, and holocellulose contents of 82–83% were determined. The thermal decomposition for the biomass samples proceeded with five stages attributed to the evaporation of some volatile compounds (70–150 ºC), to the degradation of hemicellulose (180–230 ºC), to the cellulose volatilization (250–350 ºC), to the lignin decomposition (380–550 ºC), and to the degradation of complex polymers and inorganic salts, respectively. The stage corresponding to the cellulose decomposition showed rapid mass decreased in the three residues. This results show that the cellulose and lignin content is another important parameter to evaluate the pyrolysis characteristics of a good precursor of activated carbon.
ARTICLE | doi:10.20944/preprints202211.0110.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: drip irrigation; maize; irrigation quotas; biomass; yield; irrigation water use efficiency
Online: 7 November 2022 (06:43:26 CET)
Drip irrigation systems are becoming more and more mature and are present extensively applied to increase crop yield and water use efficiency in Xinjiang, northwest China. To investigate the effects of irrigation quota on maize growth, the grain yield, and the irrigation water use efficiency (IWUE), a field experiment with four irrigation quotas (T1 4200m3·hm-2, T2 4800m3·hm-2, T3 5400m3·hm-2 and T4 6000m3·hm-2.) were conducted from 2013 to 2021 in Xinjiang China. The re-sults showed significant changes in maize growth, yield, and irrigation water use efficiency in response to different irrigation quotas. The plant height, leaf area index, SPAD, biomass, yield and harvest index of maize at different irrigation quotas all showed a “single peak curve”, and its change was closely related to the irrigation level. The growth index, dry matter accumulation, yield and irrigation water use efficiency with T3 were the highest. The dry matter transfer effi-ciency, contribution of dry matter translocation to grain and the harvest index with T3 showed significant increase of 13.86%, 26.06%, 29.93% and 7.62% compared to T1, respectively. In com-parison to T1, T2 and T4, the yield of T3 increased by 32.17%, 13.54% and 11.27% respectively, and the irrigation water use efficiency (IWUE) increased by 2.80%, 0.93% and 23.63% respectively. The significant correlations established between the maize yield and irrigation quotas could be sim-ulated by kuznets-style relation. The maize yield was negative correlated with irrigation quotas, When the irrigation quota (x) was 5376.73m3·hm-2, the maize yield (y) was 15841.00m3·hm-2. These results demonstrate that the optimized irrigation quota (5400m3·hm-2 treatment) can effectively improve the growth, yield and irrigation water use efficiency of drip irrigation maize in North-west China. In the meanwhile, it can provide theoretical reference and data support for the op-timal irrigation amount of drip irrigation maize in Northwest Xinjiang.
ARTICLE | doi:10.20944/preprints202210.0190.v1
Subject: Earth Sciences, Geoinformatics Keywords: Above-ground biomass; mangroves; pneumatophores; terrestrial LiDAR; machine learning; random forest
Online: 13 October 2022 (08:14:07 CEST)
Accurately quantifying the above-ground volume (AGV) and thus above-ground biomass (AGB) of forest stands is an important aspect in the conservation of mangrove ecosystem owing to their ecological and economic benefits. However, the number of studies focusing on quantifying mangrove forests’ biomass has been relatively low due to their marshy terrain, making exploratory studies challenging. In recent times, the use of LiDAR technologies in forest inventory studies has become increasingly popular, due to the reliability of LiDAR as a highly accurate means of 3D spatial data acquisition. In this study, we propose an end-to-end methodology for estimating AGV of mangrove forest stands from terrestrial LiDAR data. Many of the recent studies on this topic effectively employ machine learning algorithms such as multi layer perceptron, random forests, etc. for filtering foliage in the point cloud data of single trees. This study further extends that approach by incorporating the impact of class imbalance of forest point cloud data in a weighted random forest classifier. For the task of segmentation of wood/foliage points in a single tree point cloud, this approach yielded an average increase of 2.737% in the balanced accuracy score, 0.007 in the Cohen’s kappa score, 2.745% in the ROC AUC score and 0.857% in the F1 score. For the task of AGV estimation of a single tree, this approach resulted in an average coefficient of determination of 0.93 with respect to the ground truth volumes. For the task of counting pneumatophores in a plot-level point cloud, the proposed breadth-first searching method yielded an average coefficient of determination of 0.9391. Also, the machine learning classifier and geometric features used in this study were invariant to tree species and hence could be generalised for the classification of point clouds of other tree species as well. Finally, a breadth-first graph-search segmentation based approach is also proposed as part of this pipeline to estimate the contribution of pneumatophores to the AGB of mangrove forest stands. Since pneumatophores are a special adaptation of mangrove forests for gaseous exchange in marshy environments, this study aims to incorporate the detection and AGB estimation of pneumatophores in the inventory of mangrove forest stands. Studying the contribution of pneumatophores to the AGB of mangrove forest plots could also aid future mangrove forest inventory studies in modeling the underlying root network and estimating the below-ground biomass of mangrove trees.
ARTICLE | doi:10.20944/preprints202203.0299.v1
Subject: Life Sciences, Other Keywords: Biomass; Carbon pool; Indigenous agroforestry system; Coffee; Enset; South-eastern Ethiopia
Online: 22 March 2022 (10:51:01 CET)
The role of agroforestry systems in providing ecosystem services is very crucial. The most significant increase in carbon (C) storage is often achieved by moving from lower biomass land-use systems to tree-based systems like agroforestry (AF). However, estimation of carbon stocks in indigenous agroforestry systems of South-eastern Rift- valley landscapes, Ethiopia the data are scarce. The study was aimed to investigate the biomass, biomass carbon (BC), and soil organic carbon (SOC) stock of Enset based, Enset-Coffee based, and Coffee-Fruit tree-Enset based agroforestry systems. Comparison of SOC stock of agroforestry systems against their adjacent monocropping farms was also investigated. The study was conducted in three selected sites of the Dilla Zuria district of Gedeo zone. Twenty farms (total of 60) representative of each AF system were randomly selected, inventoried and biomass C stocks estimated. Ten adjacent mono-cropping farms which were related to each AF system were selected in a purposive manner for comparison of SOC stock. Inventory and soil sampling were employed in the 10×10 m farm plot. The mean aboveground biomass ranged from 81.1 t ha-1 to 255.9 t ha-1 and for belowground biomass from 26.9 t ha-1 to 72.2 t ha-1. The highest C stock was found in Coffee-Fruit tree-Enset based (233.3±81.0 t ha-1), and the lowest was in Coffee-Enset based agroforestry system (190.1±29.8 t ha-1). The result showed that SOC stocks were not statistically significant between the three AF systems, although they showed a significant difference in their BC stock. The AF systems' C stocks are substantially higher than those reported for tropical forests and other AF systems. The SOC of AF systems was significantly higher than the ones for the adjacent monocropped farms. Therefore, it is possible to deduce that AF systems are storing significant amount of C and contributing to climate change mitigation.
ARTICLE | doi:10.20944/preprints202201.0112.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: Life Cycle Assessment; hydrogen production; natural gas steam reforming; biomass gasification
Online: 10 January 2022 (12:41:26 CET)
CONTEXT– Energy is widely involved in human activity and corresponding emissions of SOX, NOX and CO2 from energy generation processes affect global climate change. Clean fuels are desired by society because of their reduced greenhouse gas emissions. Hydrogen is once such candidate fuel. Much hydrogen is produced from fossil fuel, with biomass being an alternative process. OBJECTIVE– The project compared the environmental impact of hydrogen production by natural gas steam reforming vs. biomass gasification. METHOD–Environmental impact was calculated from the input and output data from life cycle inventory analysis. The impact assessment was focused on greenhouse gas emission, acidification, and eutrophication. Models of the two processes were developed and analysed in OpenLCA. The agribalyse database was used to connect inventory flow data to environmental impacts. FINDINGS– For all three metrics, biomass gasification had lower impacts than natural gas steam reforming, sometimes by large margins. For biomass gasification the silica sand production contributes most to all three impact categories, whereas for natural gas steam reforming it is the LPG extraction.
ARTICLE | doi:10.20944/preprints202105.0209.v1
Subject: Materials Science, Biomaterials Keywords: biomass; fly ashes; X-ray diffraction; chemical analysis; multi-methodic analysis
Online: 10 May 2021 (15:12:28 CEST)
A multi-methodic analysis was performed on 5 samples of fly ashes coming from different biomasses. The aim of the study was to evaluate their possible re-use and their dangerousness for men and environment. Optical granulometric analyses indicate that the average diameter of the studied fly ashes is around 20 µm, whereas only ~1 vol% has diameter lower that 2.5 µm. The chemical composition, investigated with electron probe microanalysis, indicates that all the samples have a prevalent Ca composition, followed by Si and Al. A large content in K and P was observed in some samples, whereas the content in potentially toxic elements is always below the Italian law thresholds. Polycyclic aromatic hydrocarbons are completely absent in all the samples coming from combustion plants, whereas they are present in the fly ashes from the gasification center. Quantitative mineralogical content, determined by Rietveld analysis of X-ray powder diffraction data, indicates that all the samples have a large amorphous content, likely enriched in Ca, and several K and P minerals, such as sylvite and apatite. The results obtained from the performed chemo-mineralogical study allowed to point out that the biomass fly ashes could be interesting materials (1) as amending in clayey soils, in substitution to lime, to stimulating pozzolanic reaction and improve their geotechnical properties, on the one hand, avoiding to mine raw materials and, on the other hand, re-cycling wastes; (2) as agricultural fertilizes made by a new and ecological source of K and P.
ARTICLE | doi:10.20944/preprints202011.0564.v1
Subject: Life Sciences, Biochemistry Keywords: Chromium; Oxidative stress; Sorghum; Biomass; Toxicity; Adversely; Nutritive; Heavy metal; Tolerant
Online: 23 November 2020 (08:57:45 CET)
Sorghum is a multipurpose crop, but Cr(VI) toxicity influenced the production of the crop and have established highlighted courtesy, due to robust toxicity and a comparatively less known mode of action. Many reports approve the negative impact of Cr(VI) on plants. Yet, it is not clear that, at what concentrations, Cr(VI) inhibits the growth and nutrient quality of Sorghum. In the present research, toxic effects appeared after 1ppm of Cr treatment. The plant growth decreased 15 – 20% and nutritional quality decreased 30 – 40% significantly with increasing concentration of Cr(VI). Toxic components increased 14 – 16% with increasing concentration of Cr(VI) in both the varieties (HJ 541 and SSG 59-3). Chromium was accumulated more in roots followed by shoots with increasing Cr(VI) treatments (0-4 ppm). Chromium at 4ppm level was becoming lethal to Sorghum. Sorghum cultivar SSG 59-3 was more tolerable to Cr toxicity than HJ 541. Chromium accumulated in Sorghum and increased HCN content and at higher doses adversely affects the nutritive values and growth making it toxic for animal consumption. These findings may be useful for scheming a mitigation strategy for chromium toxicity.
ARTICLE | doi:10.20944/preprints202010.0565.v1
Subject: Biology, Anatomy & Morphology Keywords: ARIMA, CPUE, Fish biomass landings, Forecasting, Lake Malombe, Time series approach
Online: 27 October 2020 (21:04:35 CET)
Lake Malombe fish stocks have been depleted by chronic overfishing. Various management approaches (co-management, command control, and ecosystem-based management to fisheries) have been used to manage the fishery. However, the lack of an accurate predictive model has hampered their success. Therefore, we developed and tested a time series model for Lake Malombe fishery. The seasonal fish biomass and CPUE trends were first observed and both were non-stationary. The second-order differencing was applied to transform the non-stationary data into stationary. Autocorrelation functions (AC), partial autocorrelation function (PAC), and Akaike information criterion (AIC) were estimated, which led to the identification and construction of autoregressive integrated moving average (ARIMA) models, suitable in explaining the time series and forecasting. The results showed that ARIMA (1,2,1) provided a better prediction than its counterparts. The model satisfactorily predicted that by 2032, both fish biomass and CPUE will decrease to 3204.6 tons and 59.672 respectively, signifying the potential threat to Lake Malombe fishery. The model justified the necessity of taking precautionary measures to avoid the total collapse of the fishery.
ARTICLE | doi:10.20944/preprints202010.0157.v1
Subject: Earth Sciences, Atmospheric Science Keywords: PM2.5; biomass burning; long-range transport of PM2.5; Source of PM2.5
Online: 7 October 2020 (11:23:14 CEST)
This paper aims to investigate the airflow that can transport emission sources of PM2.5 from neighboring countries to contribute to air pollution in northern Thailand. We applied the coupled atmospheric and air pollution model which is based on the Weather Research and Forecasting Model (WRF) and a Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT). The model output was compared to the ground-based measurement from the Pollution Control Department (PCD) to examine model performance. As a result of model evaluation, the meteorological variables fairly agreed well compared to observation with Index of Agreement (IOA) in ranges of 0.57 to 0.79 for temperature and 0.32 to 0.54 for wind speed, while the fractional bias of temperature and wind speed were 1.3 to 2.5 °C and 1.2 to 2.1 m/s. Burma was a country that contributed much of hotpot locations by 37% of the entire hotspot locations of Southeast Asia in March. The influence of the Asian Monsoon can bring pollutants from neighboring countries such as Burma and Laos toward northern Thailand in March that likely contribute to high concentrations of PM2.5 in northern Thailand.
ARTICLE | doi:10.20944/preprints202008.0335.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Biomass burning; SMOKE; NCO; GFASv1.3; Black carbon; Organic carbon; Southern Hemisphere
Online: 15 August 2020 (04:19:14 CEST)
Wildfires generate large amounts of atmospheric pollutants yearly. The development of an emissions inventory for this activity is a challenge today, mainly to perform modeling of air quality. There are free available databases with historical information about this source. The main goal of this study was to process the results of biomass burning emissions for the year 2014 from the Global Fire Assimilation System (GFAS). The pollutants studied were the black carbon, the organic carbon, fine and coarse particulate matter, respectively. The inputs were pre-formatted to enter to the simulation software of the emission inventory. In this case, the Sparse Matrix Operator Kernel Emissions (SMOKE) was used and the values obtained in various cities were analyzed. As a result, the spatial distribution of the forest fire emissions in the Southern Hemisphere was achieved, with the polar stereographic projection. The highest emissions were located in the African continent, followed by the northern region of Australia. Future air quality modeling at a local level could apply the results and the methodology of this study. The biomass burning emissions could add a better performance of the results and more knowledge on the effect of this source.
ARTICLE | doi:10.20944/preprints202007.0576.v4
Subject: Earth Sciences, Atmospheric Science Keywords: carbon dioxide; global warming; sequestration; carbon cycle; biomass sequestration, carbon sequestration, CO2
Online: 15 January 2021 (12:34:52 CET)
Many corporations aspire to become Net Zero Carbon Dioxide by 2030-2050. This paper examines what it will take. It requires understanding where energy is produced and consumed, the magnitude of CO2 generation, and the Carbon Cycle. Reviews are provided for prior technologies for reducing CO2 emissions from fossil to focus on their limitations and to show that none offer a complete solution. Both biofuels and CO2 sequestration reduce future CO2 emissions from fossil fuels. They will not remove CO2 already in the atmosphere. Planting trees has been proposed as one solution. Trees are a temporary solution. When they die, they decompose and release their carbon as CO2 to the atmosphere. The only way to permanently remove CO2 already in the atmosphere is to break the Carbon Cycle by growing biomass from atmospheric CO2 and sequestering biomass carbon. Permanent sequestration of leaves is proposed as a solution. Leaves have a short Carbon Cycle time constant. They renew and decompose every year. Theoretically, sequestrating a fraction of the world’s tree leaves can get the world to Net Zero without disturbing the underlying forests. This would be CO2 capture in its simplest and most natural form. Permanent sequestration may be achieved by redesigning landfills to discourage decomposition. In traditional landfills, waste undergoes several stages of decomposition, including rapid initial aerobic decomposition to CO2, followed by slow anaerobic decomposition to methane and CO2. The latter can take hundreds to thousands of years. Understanding landfill chemistry provides clues to disrupting decomposition at each phase.
Subject: Life Sciences, Biotechnology Keywords: single cell oil; biomass; PUFA; docosahexaenoic acid (DHA); fish byproducts; biodiesel
Online: 5 August 2019 (04:13:54 CEST)
The following study reports on the first thraustochytrid isolates identified from Iceland. They were collected from three different locations off the northern coast of the country (Location A, Skagaströnd; Location B, Hveravík; and Location C, Eyjafjörður). Using 18S rDNA sequence analysis, isolates from Locations A and B were identified within the Thraustochytrium kinnei species while other isolates within the Sicyoidochytrium minutum species when compared to other known strains. Cells isolated from Locations A (2.10 ± 0.70 g/L) and B (1.54 ± 0.17 g/L) produced more biomass than the ones isolated from Location C (0.43 ± 0.02 g/L). This study offers the first-time examination of the utility of byproducts from fisheries as a nitrogen source in media formulation for thraustochytrids. Experiments showed that isolates produced more biomass (per unit of substrate) when cultured on nitrogen of marine (2.55 ± 0.74 g/L) as compared to of commercial origin (1.06 ± 0.57 g/L). Glycerol (2.43 ± 0.56 g/L) was a better carbon source than glucose (1.84 ± 0.57 g/L) in growth studies. Fatty acid (FA) profiles showed that the isolates from Location C (S. minutum) had low ratios of monounsaturated (4.21 ± 2.96%) and omega-6 (0.68 ± 0.59%) FAs. However, the isolates also had high ratios of docosahexaenoic acid (DHA; 35.65 ± 1.73%) and total omega-3 FAs (40.39 ± 2.39%), indicating that they could serve as a source of marine oils for human consumption and in aquaculture feeds. The T. kinnei isolates from Location A could be used in biodiesel production due to their high ratios of monounsaturated (18.38 ± 6.27%) long chain (57.43 ± 8.27%) FAs.
ARTICLE | doi:10.20944/preprints201906.0176.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: root biomass; wheat; field crops; black-grass; high-throughput; variety trials
Online: 18 June 2019 (12:51:51 CEST)
Root research on field grown crops is hindered by the difficulty of estimating root biomass in soil. Root washing, the current standard method is laborious and expensive. Biochemical methods to quantify root biomass in soil, targeting species-specific DNA, have potential as a more efficient assay. We combined an efficient DNA extraction method, designed specifically to extract DNA from soil, with well-established quantitative PCR methods to estimate the root biomass of twenty-two wheat varieties grown in field trials over two seasons. We also developed an assay for estimating root biomass for black-grass, a common weed of wheat cultivation. Two robust qPCR assays were developed to estimate the quantity of plant root DNA in soil samples, one specific to wheat and barley, and a second specific to black-grass. The DNA qPCR method was comparable, with high correlations, with the results of root washing from soil cores taken from winter wheat field trials. The DNA qPCR assay showed both variety and depth as significant factors in the distribution of root biomass in replicated field trials. The results suggest that these DNA qPCR assays are a useful, high throughput tool for investigating the genetic basis of wheat root biomass distribution in field grown crops, and the impact of black-grass root systems on crop production.
ARTICLE | doi:10.20944/preprints201810.0449.v1
Subject: Life Sciences, Biotechnology Keywords: green algae; biomass; fatty acids; Tetraselmis straiata; lipids; carotenoids; raceway ponds
Online: 19 October 2018 (11:09:56 CEST)
In the process of modernization and development, a human being always needed energy, which increased the dependency on the available sources of fossil fuel. Tetraselmis, a green algal genus belong to the order Chlorodendrales, are described by their strong green coloured chloroplast, flagellated cell bodies, and the occurrence of a pyrenoid within the chloroplast. In this study, four different strains of Tetraselmis species were successfully isolated from the saltpans Kovelong, Chennai, Tamil Nadu, India. The isolated strains were cultured in the normal basal medium and their morphological features were subsequently studied. The species of Tetraselmis straiata (T. straiata) Butcher BBRR1 was confirmed using molecular identification of 18S rRNA gene analysis and its observed systematic position. Among the four different isolates, T. straiata Butcher BBRR1 recorded a highest biomass concentration of 0.58 ± 0.021 g L-1, 15% lipids, 19% proteins and 17% carbohydrates when it grown under laboratory condition. Whereas, in open raceway ponds, T. straiata BBRR1 produced 0.95 ± 0.06 g L-1 biomass, 19% lipids, 28% proteins and 21% carbohydrates in an modified CFTRI I medium. The fatty acids profile of T. straiata Butcher BBRR1showed the presence of 33.14 % Palmitic acid, 22.64% 11- Octadecenoic acid and 21.94% Heptadecanoic acid. Since T. straiata BBRR1 can be cultivated in open ponds without a major contaminations, this species can be used as novel biomass feedstock to produce biofuels. This study may suggest the potential of T. straiata BBRR1 for biofuel production and could compete the energy demand in the future. In addition, this species contains healthful components of carotenoids, lipids and proteins, all these may provide a health benefits beyond basic nutrition.
REVIEW | doi:10.20944/preprints201806.0170.v1
Subject: Engineering, Other Keywords: forest biomass; timber harvest residue; supply chain; trucking; delivery; logging residue
Online: 12 June 2018 (07:53:15 CEST)
Secondary transportation of raw and comminuted forest products is a major component in forest harvesting operations in terms of economics, public perception, and safety. Consequently, there is a substantial amount of literature on this topic. The existing literature has dealt with many of the technical aspects of transportation with a majority of them focusing on improving supply chain issues; However, there are only few specific to secondary transportation issues in general. This annotated bibliography will help practitioners, researchers, and stakeholders gain a better understanding of the existing literature from 2000 to 2015. To this end, we began by classifying the selected literature into six themes: cost, roads and routes, trucking, efficiency & safety, other modes of transportation, and supply chain & optimization. Woody biomass for bioenergy production was the most researched forest product with respect to transportation. About one-third of the articles were presented in the context of supply chain modeling and optimization. More than half of the studies originated from Europe while the United States had the most publications for any given country. The most articles (16) were published in 2013. Biomass and Bioenergy published the highest number of articles (29) during the timeframe.
ARTICLE | doi:10.20944/preprints201612.0020.v1
Subject: Biology, Forestry Keywords: natural secondary forest; planted forest; vegetation biomass carbon; soil organic carbon
Online: 3 December 2016 (09:25:48 CET)
Forest ecosystems make a greater contribution to carbon (C) stocks than any other terrestrial ecosystem. To understand the role of regional forest ecosystems in global climate change and carbon exchange, forest C stock and its spatial distribution within the small (2,300 km2) Liuxihe River basin were analyzed to determine the different contributors to the C stock. Forest C stocks were quantified by measuring the biomass of trees, understory vegetation, litter and roots, as well as soil organic C, using data from field samples and laboratory experiments. The results showed that forests stored 38.04 Tg C in the entire basin, with secondary and planted forests accounting for 89.82% and 10.18%, respectively, of the stored C. Five types of forests, a subtropical evergreen broad-leaved forest, a subtropical coniferous and broad-leaved mixed forest, a subtropical coniferous forest, a timber forest, and a non-wood forest, stored 257.55 ± 15.01, 218.92 ± 9.59, 195.24 ± 18.29, 177.42 ± 17.55, and 117.86 ± 6.04 Mg C ha−1, respectively. In the forest ecosystem C stocks of the basin, soils averagely contribute about 73.78%, not including root underground biomass. It provides a comprehensive method for forest ecosystem carbon investigation and forest management in small basin scale.
REVIEW | doi:10.20944/preprints202211.0567.v1
Subject: Life Sciences, Biotechnology Keywords: Keywords: Integrated biorefinery; Circular economy; Lignocellulosic biomass; Pretreatment; Valorization; Enzymes; Biofuels; Biochemicals
Online: 30 November 2022 (08:50:21 CET)
An upsurge in global population over the years and rapid urbanization have accelerated huge dependence on petroleum-derived fuels and consequent environment concerns owing to green-house gas emissions in the atmosphere. An integrated biorefinery uses lignocellulosic feedstock as raw material for the production of renewable biofuels, and other fine chemicals. The sustain-able bio-economy and the biorefinery industry would benefit greatly from the effective use of lignocellulosic biomass obtained from agricultural feedstocks to replace petrochemical products. Lignin, cellulose, hemicellulose, and other extractives, which are essential components of ligno-cellulosic biomass, must be separated or upgraded into useful forms in order to fully realize the potential of biorefinery. The development of low-cost and green pretreatment technologies with effective biomass deconstruction potential is imperative for an efficient bioprocess. The abun-dance of microorganisms along with their continuous production of various degradative en-zymes makes them suited for the environmentally friendly bioconversion of agro-industrial wastes into viable bioproducts. The present review highlights the concept of biorefinery, ligno-cellulosic biomass and its valorization by green pretreatment strategies into biofuels and other biochemicals. The major barriers and challenges in bioconversion technologies, environmental sustainability of the bioproducts and promising solutions to alleviate those bottlenecks are also summarized.
ARTICLE | doi:10.20944/preprints202211.0560.v1
Subject: Life Sciences, Other Keywords: airways obstruction; biomass smoke; COPD; cytokines; eosinophils; impulse oscillome-try; tobacco smoking
Online: 30 November 2022 (03:40:46 CET)
COPD is a chronic inflammatory disease characterized by progressive airflow obstruction. Tobacco smoking is the main cause of COPD (COPD-TS), but chronic exposure to biomass smoke (COPD-BS), mainly wood smoke, is the second risk factor; both are considered to cause different phenotypes of COPD. COPD-BS is more eosinophilic than COPD-TS. The objective of the present study was to evaluate the serum level of interleukins involved in eosinophil maturation, recruitment, and survival, and their association with small airway obstruction, measuring cytokines by multiplex test (Bio-Plex) and evaluating the central airway resistance with impulse oscillometry (IOS), comparatively in patients with COPD due to biomass and smoking. The results showed that IL-1ra, IL-2, IL-4, IL-8, IL-9, IL-13, IL-17, and eotaxin were increased in COPD-BS related to COPD-TS. Resistance parameters showed that R5, X5, AX (area reactance), and R5-R20 were significantly higher in COPD-BS than in the COPD-TS group (p < 0.05). R20 was not different between the groups. These data suggest that the cytokines involved in the effect of eosinophils on airway inflammation in COPD-BS were increased compared with COPD-TS, which appears to be related to a predominance of peripheral airway obstruction in patients with COPD-BS more than in COPD-TS
ARTICLE | doi:10.20944/preprints202106.0212.v4
Subject: Earth Sciences, Atmospheric Science Keywords: Carbon Dioxide; Net Zero; Sequestration; Biomass; Direct Capture; Global Warming; Landfills; Forestry
Online: 2 November 2021 (10:53:39 CET)
Many corporations and governments aspire to become Net Zero Carbon Dioxide by 2030-2050. Achieving this goal requires understanding where energy is produced and consumed, the magnitude of CO2 generation, and the Carbon Cycle. Many prior proposed solutions focus on reducing future CO2 emissions from continued use of fossil fuels. Examination of these technologies exposes their limitations and shows that none offer a complete solution. For example, bioethanol is shown to be both carbon and energy inefficient. Direct Air Capture technologies are needed to reduce CO2 already in the air. The most natural form of Direct Air Capture involves letting nature do the work of creating biomass via photosynthesis. However, it is necessary to break the Carbon Cycle by permanently sequestering that biomass carbon in “landfills” modified to discourage decomposition to CO2 and methane. Tree leaves and biomass grown on-purpose, such as high yield switchgrass, are proposed as good biomass sources for this purpose. Left unsequestered, leaves decompose with a short Carbon Cycle time constant releasing CO2 back to the atmosphere. While in any given year, leaves represent a small fraction of a tree’s above ground biomass, leaves can represent a substantial fraction of the total biomass generated by a tree when integrated over a tree’s lifetime. Understanding the chemistry of the distinct phases landfills undergo is the key to minimizing or eliminating decomposition. First, the compact cross-linked structure of cellulose and keeping water out will make it difficult for initial depolymerization to release sugars. Air ingress should be minimized to minimize Phase I aerobic decomposition. pH manipulation can discourage acid formation during Phase II. Lignocellulose is low in nutrients needed for anaerobic decomposition. Inhibitors can be added if needed. The goal is to move quickly to the dormant phase where decomposition stops. The cost for Carbon Capture and Storage (CCS) for growing and sequestering high yield switchgrass is estimated to be lower than CCS for steam reforming of methane hydrogen plants (SRM) and supercritical or combined cycle coal power plants. Thus, sequestration of biomass is a natural, carbon efficient, and low-cost method of Direct Capture. Biomass sequestration can provide CO2 removal on giga tonnes per year scale and can be implemented in the needed timeframe (2030-2050).
ARTICLE | doi:10.20944/preprints202104.0594.v1
Subject: Engineering, Automotive Engineering Keywords: lignocellulosic biomass; wheat straw; anaerobic digestion; chemical pretreatment; ultrasound pretreatment; biogas enhancement.
Online: 22 April 2021 (09:10:33 CEST)
Biomass is an attractive energy source that can be used for production of heat, power, and transport fuels, and when produced and used on a sustainable basis, can make a large contribution to reducing greenhouse gas (GHG) emissions. Anaerobic digestion (AD) is a suitable technology for reducing organic matter and generating bioenergy in the form of biogas. This study investigates the factors allowing the optimization of the process of biogas production from the co-digestion of wheat straw (WS) and bovine manure. The statistical analysis of the experiments carried out show that ultrasonic processing plays a fundamental role by sonication density and solids concentration leading to improved characteristics of WS by reducing particle size and increasing concentration of soluble chemical oxygen demand. The higher the sonicating power used, the more the waste particles are disrupted. The optimality obtained under mesophilic conditions for WS pretreated with 4% w/w (weight by weight) H2O2 at temperature 36 °C under 10 minutes of ultrasonication at 25 kHz improves the methane yield by 64%.
REVIEW | doi:10.20944/preprints202009.0674.v1
Subject: Engineering, Automotive Engineering Keywords: microalgal biomass; thermochemical conversion; catalytic upgrading; liquid fuels; hydrothermal liquefaction; pyrolysis; gasification
Online: 27 September 2020 (10:35:33 CEST)
Over the last decades, microalgal biomass has gained a significant role in the development of different high-end (nutraceuticals, colorants, food supplements, and pharmaceuticals) and low-end products (biodiesel, bioethanol, and biogas) due to rapid growth and high carbon fixing efficiency. Therefore, microalgae are considered a useful and sustainable resource to attain energy security while reducing our current reliance on fossil fuels. From the technologies available for obtaining biofuels using microalgae biomass, thermochemical processes (pyrolysis, HTL, gasification) have proven to be processed with higher viability, because they use all biomass. However, because of the complexity of the biomass (lipids, carbohydrates , and proteins), the obtained biofuels from direct thermochemical conversion have large amounts of heteroatoms (oxygen, nitrogen , and sulfur). As a solution, catalyst-based processes have emerged as a sustainable solution for the increase in biocrude production. This paper's objective is to present a comprehensive review of recent developments on catalyst mediated conversion of algal biomass. Special attention will be given to operating conditions, strains evaluated, and challenges for the optimal yield of algal-based biofuels through pyrolysis and HTL.
ARTICLE | doi:10.20944/preprints202007.0539.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Total organic carbon; Total nitrogen; Soil microbial biomass; Vegetation types; Hongqipao reservoir
Online: 23 July 2020 (08:13:39 CEST)
This study investigated the spatial variability of soil organic carbon (SOC), total nitrogen (TN), soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN) in Hongqipao reservoir dominated by different vegetation types and the possible relationships with other soil properties. Top 0–50cm soil samples were collected in sites dominated by different vegetation types within the reservoir littoral zone. There was high spatial variability for SOC, TN, SMBC and SMBN in the Hongqipao reservoir. In addition, the SOC, TN, SMBC and SMBN contents decreased with increasing soil depth. This could be attributed by the fact that when plants detritus decompose, most of their organic matter is mineralized and a new soil layer which contains a greater amount of organic carbon is formed at the top. According to Pearson's correlation values and redundancy analysis (RDA) results, SOC was significantly and positively correlated with TN likely because the vegetation organic matter and liter could be the main nitrogen sources. Similarly, soil moisture content (MC) was significant positive correlated with SOC and TN. Conversely, BD was significant negative correlated with SOC and TN contents in the 0-50 cm soil profiles. However, no significant correlations were observed between SOC, TN, SMBC and SMBN contents and soil pH values. SMBN was significantly and positive correlated with C:N ratio and BD and negative related with MC. Multiple linear regression model revealed that all measures soil properties in this study could explain higher significant variability of the response variables (SOC, TN, SMBC and SMBN contents). This implies that all the measured soil variables within the different vegetation types in the reservoir played a crucial role in determining the contents of SOC, TN, SMBC and SMBN. This study further suggests that vegetation types play a major role in determining the spatial characteristics of SOC and TN. Any changes in the vegetation types in the reservoir may influence the distribution of SOC and TN. This may affect the global carbon budget and the atmospheric greenhouse gas concentration significantly.
ARTICLE | doi:10.20944/preprints202004.0205.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: hydrothermal carbonization; lignocellulosic biomass; reaction kinetic; nonlinear regression model; waste-to-energy
Online: 13 April 2020 (03:32:24 CEST)
This study presents a new kinetic scheme for the mass yield prediction of waste lignocellulosic biomasses treated by Hydrothermal Carbonization (HTC). The proposed reactions are based on the decomposition, solubilization, and polymerization of each main fraction of the biomass: cellulose, hemicellulose, and lignin. The ash content was assumed to be inert. The kinetic parameters have been obtained by non-linear adjustment using a data set with 220 experimental runs collected from the literature. The results indicate that the pre-exponential factors range was from 7.33 x101 to 1.412x105 min-1, and activation energies were between 33.75 y 225.3 kJ/mol. A good fit is achieved between the observed and predicted data with an R2 of 0.81 and an RMSE of 7.7 %. The proposed scheme was validated with the experimental data obtained by the HTC of sawdust (Pinus radiata) and rapeseed (Brassica napus). The experiments were carried out at temperatures of 190, 220, and 250 ºC and reaction times of 0, 30, 60, 90, and 120 min. The predicted values showed an average error of 2.3 and 3.5 %, respectively. Therefore, the kinetic scheme is a useful tool in the conversion analysis of waste biomass treated by HTC.
ARTICLE | doi:10.20944/preprints201911.0145.v1
Subject: Earth Sciences, Atmospheric Science Keywords: biomass burning; residential wood combustion; aerosol mass spectrometry; potassium; chemical transport model
Online: 13 November 2019 (11:34:33 CET)
Alkali-containing submicron particles were measured continuously during three months, including late winter and spring seasons in Gothenburg, Sweden. The overall aims were to characterize the ambient concentrations of combustion-related aerosol particles and to address the importance of local emissions and long-range transport for the atmospheric concentrations in the urban background environment. K and Na concentrations in the PM1 size range were measured by an alkali aerosol mass spectrometer (Alkali-AMS) and a cluster analysis was conducted. Local meteorological conditions and some other data sets were obtained, and back trajectory analyses and chemical transport model (CTM) simulations were included for the evaluation. The Alkali-AMS cluster analysis indicated three major clusters: 1) biomass burning origin, 2) mixture of other combustion sources, and 3) marine origin. Low temperatures and low wind speed conditions correlated with high concentrations of K-containing particles, mainly due to regional emissions from residential biomass combustion; transport of air masses from continental Europe also contribute to cluster 1. The CTM results indicate that open biomass burning in the eastern parts of Europe may have contributed substantially to high PM2.5 concentrations (and to cluster 1) during an episode in late March. According to the CTM results the mixed cluster (2) is likely to include particles emitted from different source types and no single geographical source region seems to dominate for this cluster. The back trajectory analysis and meteorological conditions indicated that the marine origin cluster was correlated with westerly winds and high wind speed; this cluster had high concentrations of Na-containing particles, as expected for sea salt particles.
ARTICLE | doi:10.20944/preprints201904.0020.v1
Subject: Chemistry, Chemical Engineering Keywords: Hydrotreating, mesoporous sulfide materials, waste Jatropha biomass, drop-in biofuels, upgrading technology
Online: 1 April 2019 (13:51:53 CEST)
The bio-oil was largely produced by thermal pyrolysis of Jatropha-derived biomass wastes (denoted as Jatropha bio-oil) using a Pilot Plant with a capacity of 20 kg h-1 at Thailand Institute of Scientific and Technological Research (TISTR), Thailand. Jatropha bio-oil is an unconventional type of bio-oil, which is mostly composed of fatty acids, fatty acid methyl esters, fatty acid amides and derivatives, and consequently it contained large amounts of heteroatoms (oxygen ~ 20 wt.%, nitrogen ~ 5 wt.%, sulfur ~ 1000 ppm.). The heteroatoms, nitrogen especially, are highly poisonous to the metal or sulfide catalysts for upgrading of Jatropha bio-oil. To overcome this technical problem, we reported a stepwise strategy for hydrotreating of 100 wt% Jatropha bio-oil over mesoporous sulfide catalysts of CoMo/γ-Al2O3 and NiMo/γ-Al2O3 to produce drop-in transport fuels, such as gasoline- and diesel-like fuels. This study is very different from our recent work on co-processing of Jatropha bio-oil (ca. 10 wt%) with petroleum distillates to produce a hydrotreated oil as a diesel-like fuel (Chen et al., Catalysts 2018, 8, 59; http://dx.doi.org/10.3390/catal8020059). Jatropha bio-oil was pre-treated through a slurry-type high pressure reactor under severe condition, resulting in a pre-treated Jatropha bio-oil with relatively low amounts of heteroatoms (oxygen < 20 wt.%, nitrogen < 2 wt.%, sulfur < 500 ppm.). The light and middle distillates of pre-hydrotreated Jatropha bio oil was then separated by distillation at temperature below 240 oC, and the temperature of 240-360 oC. Deep hydrotreating of light distillates over sulfide CoMo/γ-Al2O3 catalyst was performed on a batch-type high pressure reactor at 350 oC and 7 MPa of H2 gas for 5 h. The hydrotreated oil was a gasoline-like fuel, which contained 29.5 vol.% of n-paraffins, 14.4 vol.% of iso-paraffins, 4.5 vol.% of olefins, 21.4 vol. % of naphthene compounds and 29.6 wt.% of aromatic compounds, and little amounts of heteroatoms (nearly no oxygen and sulfur, and less than 50 ppm of nitrogen), corresponding to an octane number of 44, and it would be suitable for blending with petro-gasoline. The hydrotreating of middle distillates over sulfide NiMo/γ-Al2O3 catalyst using the same reaction condition produced a hydrotreating oil with diesel-like composition, low amounts of heteroatoms (no oxygen and less than 50 ppm of sulfur and nitrogen), and a cetane number of 60, which would be suitable for use in drop-in diesel fuel.
ARTICLE | doi:10.20944/preprints201812.0227.v1
Subject: Earth Sciences, Other Keywords: digital aerial photogrammetry; SAR; model-assisted; biomass estimation; Copernicus; unmanned aerial vehicles
Online: 19 December 2018 (02:56:20 CET)
Due to the increasing importance of mangroves in climate change mitigation projects, more accurate and cost-effective aboveground biomass (AGB) monitoring methods are required. However, field measurement of AGB may be a challenge because of its remote location and the difficulty to walk in these areas. This study is based on the Livelihoods Fund’ Oceanium project of 10,000 hectare mangrove plantations monitoring. In a first step, the possibility of replacing traditional field measurements of sample plots in a young mangrove plantation by a semiautomatic processing of UAV-based photogrammetric point clouds was assessed. In a second step, Sentinel-1 radar and Sentinel-2 optical imagery were used as auxiliary information to estimate AGB and its variance for the entire study area under a model-assisted framework. AGB was measured using UAV imagery in a total of 95 sample plots. UAV plot data was used in combination with non-parametric Support Vector Regression (SVR) models for the estimation of the study area AGB using model-assisted estimators. Purely UAV-based AGB estimates and their associated standard error (SE) were compared with model-assisted estimates using (1) Sentinel-1, (2) Sentinel-2 and (3) a combination of Sentinel-1 and Sentinel-2 data as auxiliary information. The validation of the UAV-based individual tree height and crown diameter measurements showed a root mean square error (RMSE) of 0.21 m and 0.32 m respectively. Relative efficiency of the three model-assisted scenarios ranged between 1.61 and 2.15. Although all SVR models improved the efficiency of the monitoring over UAV-based estimates, the best results were achieved when a combination of Sentinel-1 and Sentinel-2 data was used. Results indicated that the methodology used in this research can provide accurate and cost-effective estimates of AGB in mangrove young plantations.
ARTICLE | doi:10.20944/preprints201806.0128.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: biogas purification; coconut shells; biomass valorization; textural characterization; adsorption isotherms; breakthrough curves.
Online: 7 June 2018 (16:27:12 CEST)
Biomass is a widely distributed and renewable source of carbon. The main objective of this work is to produce an activated carbon from coconut shells with suitable characteristics to separate CO2 from biogas. The textural characterization of the adsorbent has been determined. Pure component adsorption isotherms of CO2 and CH4 at 30, 50 and 70 °C have been measured. Moreover, the performance of the produced activated carbon, as potential adsorbent for CO2 capture from a CO2/CH4 gas mixture has been evaluated under dynamic conditions in a purpose-built fixed-bed setup.
ARTICLE | doi:10.20944/preprints201805.0066.v1
Subject: Biology, Forestry Keywords: biomass yield; carbon storage; growth pattern; poplar; short-rotation coppices; seasonal trends
Online: 3 May 2018 (11:10:21 CEST)
It is required to manage sustainable Short-Rotation Coppices (SRCs) as an important role on carbon sink and bioenergy output, because most of SRCs were established in reclaimed land in South Korea. However, during the last three years, growth pattern of the SRCs was remarkably changed with soil condition. This study aimed to identify the sustainability of SRCs on carbon storage, biomass and fuel pellet production, monitoring the neighboring vegetation of SRCs by land-use exchange, physiological change of poplar on seasonal trend, and to evaluate whether poplar is suitable for making wood pellets. The calculated biomass yield per area of poplar grown was 103.07 Mg per total area (55.6 ha), and volumes of carbon dioxide absorption was estimated to be 330 Mg CO2. Wood pellet quality based on the criteria scored third grade, indicating that poplar is suitable for manufacturing fuel pellets. Moreover, monitoring of the flora distribution in SRCs revealed changes in species composition. As halophyte was increased during drought, soil organic matter, net growth and total chlorophyll of poplar were significantly decreased. These findings indicated that photosynthesis and growth pattern of SRCs may be negatively affected by microclimate and will provide valuable information for effective management of SRCs.
ARTICLE | doi:10.20944/preprints201803.0024.v1
Subject: Engineering, Energy & Fuel Technology Keywords: by-products; biogas; Biogasdoneright; citrus pulp; olive pomace; GIS; indicators; biomass availability
Online: 2 March 2018 (13:11:14 CET)
The necessity to investigate suitable alternatives to conventional fossil fuels has developed the interests in many renewable energy alternatives, especially biomass resources which are widely available and allow to reach both environmental and socio-economic improvements. Among the bioenergy solutions the anaerobic digestion technology makes it possible to produce biogas by reusing and valorising agricultural residues and by-products. In Southern Italy, to date, the development of biogas sector is still very limited, despite the importance of the agricultural sector, especially of citrus and olive cultivation. For this reason, in previous studies the availability of two by-products, i.e., citrus pulp and olive pomace, was analysed in order to choose the most suitable area for a sustainable development of new biogas plants according to the new Biogasdoneright concept. In this paper, after a resume of the multi-step methodology which allowed the computation of biogas production, it was demonstrated that 15.9 GWh-e electricity and 24.5 GWh-e heat per year could be generate by reusing only these two kind of by-products, and could satisfy approximate 17% of the total electricity demand of the agricultural sector (90.2 GWh-e/year) in Catania.
ARTICLE | doi:10.20944/preprints201706.0091.v1
Subject: Earth Sciences, Atmospheric Science Keywords: tropospheric emissions; CTM; tropospheric ozone; industrial emissions; biomass buring; vegetation emissions; simulation
Online: 20 June 2017 (04:28:19 CEST)
In this work, we examined the effect of tropospheric emissions on tropospheric ozone (O3) by conducting three-dimensional (3D) chemistry transport model (CTM) simulations. For the control run, the CTM model simulates tropospheric O3 levels with a complete set of anthropogenic, biomass burning, and vegetation emissions . For the no-emission simulation, all anthropogenic, biomass burning, and vegetation emissions were turned off. Comparisons of results from these two simulations exhibit the emission impacts on the tropospheric O3. In the no-emission simulation, distinctive low surface O3 with concentrations less than 5 ppbv prevail over the Amazon basin, tropical South America, tropical South Africa, Southeast Asia. Transport of air from these land areas downwind contributes to the low O3 over the remote marine boundary layer. In contrast, elevated O3 levels over the extra-tropical remote marine boundary layer are less supported by the anthropogenic and biomass burning emissions but more sustained by the downward transport of O3 from the stratosphere. These results demonstrate that the northern hemisphere continental areas (north of 30◦N ), polar regions, and tropical continental regions are more sensitive to the tropospheric emissions. The northern hemisphere winter is mostly dominated by the stratospheric processes, while the tropospheric emissions dominate over the southern hemisphere tropical continental areas from tropics to 30◦S latitudinal bands. The northern hemisphere continental regions are increasingly dominated by tropospheric emissions from spring, to reach maxima in summer, and started to reduce in autumn months.
ARTICLE | doi:10.20944/preprints201704.0122.v1
Subject: Earth Sciences, Environmental Sciences Keywords: crust type; soil depth; physicochemical properties; enzyme; microbial biomass carbon and nitrogen
Online: 19 April 2017 (11:23:58 CEST)
This study investigated the effects of soil crust development on the underlying soil properties. The field sampling work was conducted in June 2016 in the Hobq Desert in Inner Mongolia, North China. Soil crust samples and 0–6, 6–12, 12–18, 18–24, 24–30 cm deep underlying soil samples were taken from five representative areas of different soil crust development stages. All samples were analyzed for physicochemical properties including water content, bulk density, aggregate content, organic matter content, enzyme activities, and microbial biomass carbon and nitrogen. The results showed that the thickness, water content, macroaggregate (>250 μm) content, organic matter content, microbial biomass and enzyme activities of the soil crusts gradually increased along the soil crust development gradient, while the bulk density of the soil crusts decreased. Meanwhile, the physicochemical and biological properties of the soils below the algal and moss crusts were significantly ameliorated when compared with the physical crust. Moreover, the amelioration effects were significant in the upper horizons (approx. 0–12 cm deep) and diminished quickly in the deeper soil layers.
ARTICLE | doi:10.20944/preprints202208.0116.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Biomass partitioning; Digital root phenotyping; Image analysis; Rhizotron; Root architecture; Root phenes; RootSnap
Online: 5 August 2022 (04:23:44 CEST)
Citron watermelon (Citrullus lanatus var. citroides) is an extremely drought-tolerant cucurbit crop widely grown in sub-Saharan Africa in arid and semi-arid environments characterized by drought. The species is a C3 xerophyte used for multiple purposes, including intercropping with maize and has a deep taproot system. The deep taproot system plays a key role in the species’ adaptation to dry conditions. Understanding root system development of this crop could be useful in identifying traits for breeding water-use efficient and drought-tolerant varieties. This study compared root system architecture of citron watermelon accessions under water-stress conditions. Nine selected and drought-tolerant citron watermelon accessions were grown under non-stress (NS) and water stress (WS) conditions using the root rhizotron procedure in a glasshouse. The following root system architecture (RSA) traits were measured, namely: root system width (RSW), root system depth (RSD), convex hull area (CHA), total root length (TRL), root branch count (RBC), total root volume (TRV), leaf area (LA), leaf number (LN), first seminal root length (FSRL), seminal root angle (SRA), root dry mass (RDM), shoot dry mass (SDM), root–shoot mass ratio (RSM), root mass ratio (RMR), shoot mass ratio (SMR) and root tissue density (RTD). The data collected on RSA traits were subjected to the analysis of variance (ANOVA), correlation and principal component analyses. ANOVA revealed a significant (p < 0.05) accession × water stress interaction effect for studied RSA traits. Under WS, RDM exhibited significant and positive correlations with RSM (r = 0.65), RMR (r = 0.66), RSD (r = 0.66), TRL (r = 0.60), RBC (r = 0.72), FSRL (r = 0.73) and LN (r = 0.70). Principal component analysis revealed high loading scores for the following RSA traits: RSW (0.89), RSD (0.97), TRL (0.99), TRV (0.90), TRL (0.99), RMR (0.96) and RDM (0.76). In conclusion, the study has shown that the identified RSA traits could be useful in crop improvement programmes for citron watermelon genotypes with enhanced drought adaptation for improved yield performance under drought-prone environments.
ARTICLE | doi:10.20944/preprints202112.0388.v1
Subject: Earth Sciences, Environmental Sciences Keywords: organic soil carbon; seasonal dynamics; biomass of microorganisms; organic nitrogen; tillage; microbial index
Online: 23 December 2021 (11:51:57 CET)
The main purpose of this study was to determine the size and direction of the seasonal dynamics of organic carbon (Сmicro) and nitrogen (Nmicro) biomass of microorganisms and microbial index (Cmicro : Corg) of natural and agrocenoses with their different uses. Field research methods involved taking of soil samples in 0-10-, 10-20- and 20-40 сm layers. Under laboratory conditions, the content of total soil carbon was determined by dry oxygen combustion on a Vario EL III analyzer (Elementar Analyzensysteme, Hanau, Germany). The carbon content of microbial biomass (Сmicro) was determined by chloroform fumigation extraction method (CFE). To freshly taken soil samples (2 hours) and soil samples after their 24-hour fumigation with chloroform vapors, 0.5 M K2SO4 was added to extract biomass lysis products of soil microorganisms. The content of organic carbon and nitrogen in the biomass of microorganisms in the obtained filtrates was determined on the Elementar Liqui TOC II, Analyzensysteme GmbH, Germany. The carbon content of microbial biomass was calculated from the difference between carbon in fumigated and control samples using a factor of 0,45 - for carbon and 0,54 – for nitrogen. The microbial index of soils was determined by the ratio between the carbon of microorganisms and the total organic carbon of the soil – Cmicro : Corg • 100 (%). Average values and confidence intervals were determined for each defined indicator. The Bonferoni method was used to correct the errors of multiple comparative samples of a one-way ANOVA analyze. K. Pearson’s linear correlation analysis was used to establish the relationships between the dynamics of carbon biomass of microorganisms and organic carbon of the soil during the growing season. Our research has shown the dynamics of Сmicro, Nmicro, Сmicro : Nmicro and Cmicro : Corg during the growing season. Analysis of the box plot showed the largest amplitude of Сmicro changes in the upper 0-10 cm layer of izogumusol. The smallest difference in the quartile range (IQR0,25-0,75) was for no-till and overhang (Ab) in the upper 0-10-, no-till (NT) and fallow (F) - in the layer 10-20- and plowing (CT) - in a layer of 20-40 cm. The content of organic carbon biomass of microorganisms in the upper layer of izogumusol at the beginning of the growing season had the highest values of Ab (577,79 1,64 mg/kg), NT (485,43 1,97 mg/kg) and CT (470,43 0,77 mg/kg), the smallest - for F (370,15 2,18 mg/kg). The content of Nmicro during this period decreased from Ab to Comb (combined tillage), NT, CT, Rot (rotary tillage), RT (reduced (ridge) tillage) and F, respectively. In the 20-40 cm layer, the highest values of Сmicro and Nmicro were observed in mid-July. The lowest values of Сmicro and Nmicro and the largest – Сmicro : Nmicro were found in late August for all variants and layers of the study. The dynamics of the microbial index resembled the trends of Сmicro and Nmicro. The largest share of Smicro in Sorghum during the growing season, on average was: - Ab (1,82 1,85 %) and NT (1,66 1,52 %) - in the layer 0-10-, - Ab (1,23 1,27 %) and NT (1,29 1,32 %) - in the layer 10-20- and - Ab (1,19 1,09 %) and F (1,11 1,077 %) - in a layer of 20-40 cm. Different use of izogumusol affected the amplitude of seasonal changes of Сmicro and Nmicro and did not affect on their direction. The maximum content of Сmicro and Nmicro was observed at the beginning of the growing season - in a layer of 0-10 cm and in mid-July - in a layer of 20-40 cm, the minimum - at the end of the summer period. During this period, the widest ratio of Сmicro : Nmicro was for F and CT - in the layer 0-20 cm and CT and Rot - in the layer 20-40 cm. The Pearson’s correlation coefficient between Сmicro and Corg increased from the upper 0-10- to the lower 20-40 cm layer of izogumusol. "Strong" and "high" negative correlations have been established between Сmicro and Corg, but no pattern has been found between the correlation coefficient and tillage technologies.