ARTICLE | doi:10.20944/preprints202210.0372.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: Keywords carbochlorination; spent lithium-ion batteries; circular economy; recycle; LiCl.
Online: 25 October 2022 (02:05:51 CEST)
The abundant use of lithium-ion batteries (LIBs) in a wide variety of electric devices and vehicles will generate a large number of depleted batteries, which contain several valuable metals such as Li, Co, Mn, and Ni present in the structure of the cathode material (LiMO2). The present work investigates chemical, technological, and environmental aspects in the treatment of such wastes, development of a methodology for the extraction of lithium, cobalt, nickel, manganese, and graphite by a carbochlorination pyrometallurgical process. Mixtures of cathode and anode materials (called black mass, mixed oxides of Li, Co, Ni, Mn, and graphite) from different LIBs, carbon black (as reducing agent), and CaCl2 (as chlorinating agent) were used. Non-isothermal thermogravimetric tests up to 850°C and isothermal tests at 700°C of the mixtures in an inert atmosphere were carried out. It was experimentally observed that the LiMO2-C-CaCl2 reaction takes place at 700°C. LiCl, Ni, and Co were obtained as final products, and to a lesser extent, CoO, NiO, and MnO2. CaCO3 was also obtained as a by-product. The obtained results show that carbochlorination is an efficient and effective alternative route for the extraction and recovery of metals from different LIBs, focused on the sustainability and circular economy
ARTICLE | doi:10.20944/preprints202203.0347.v1
Subject: Chemistry And Materials Science, Metals, Alloys And Metallurgy Keywords: Recycled graphite; high-quality graphite; spent batteries; acidic leaching
Online: 25 March 2022 (15:17:53 CET)
Spent batteries recycling is an important way to obtain low-cost graphite. Nevertheless, the obtaining of crystalline graphite with a rather low density of defects is required for many applications. In the present work, high-quality graphites have been obtained from different kinds of spent batteries. Black masses from spent alkaline batteries (batteries black masses, BBM), and lithium-ion batteries from smartphones (smartphone black masses, SBM) and electric and/or hybrid vehicles (lithium-ion black masses, LBM) were used as starting materials. A hydrometallurgical process was then used to obtain recycled graphites by acidic leaching. Different leaching conditions were used depending on the type of the initial black mass. The final solids were characterized by a wide set of complementary techniques.
ARTICLE | doi:10.20944/preprints202011.0182.v1
Subject: Physical Sciences, Acoustics Keywords: Spent Nuclear Fuel; Nuclear Fuel Cycle; Spent Fuel Storage; Spent Fuel Reprocessing; Modelling; Decay Heat; Isotopic Composition; Elemental Composition; Statistical Analysis; First Principles
Online: 4 November 2020 (09:57:42 CET)
Computational methods are essential to support and advance nuclear technologies due to the hazards of handling and analysing highly radioactive materials such as spent nuclear fuel (SNF). However, many such methods, including those thatcan predict SNF compositions and decay heat parameters, require expensive, proprietary software, alongside significant programming experience and computational power for utilisation, severely limiting availability of data and hampering research throughput. Although some datasets are available, many are incomplete or only cover certain fuel systems for older reactor types. Research investigating new methods for SNF recycling, for example, requires compositional and decay heat data for fuel systems not covered by extant data, though analogous source data may be available. With this in mind, we have developed a simple, accessible, and flexible method for extrapolation of isotopic, elemental, and decayheat compositions for SNF at discharge and following decay storage before recycling, based on an extant dataset. This semi-empirical method uses physical and mathematical first principles and can be performed using software accessible to all researchers. This provides outputs accurate to within 1% of reference values interpolated within the range of available data for isotopic compositions, with sensible extrapolations at higher burnups beyond those reported, withoverall elemental outputs accurate to within 0.1%of expected totals. In this publication, we present the developmental methodology, some sample data, the present limitations, and options for future development and expansion of functionality.
REVIEW | doi:10.20944/preprints202012.0790.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Spent Pot Lining; SPL; Aluminum; Recycle; Toxicity
Online: 31 December 2020 (11:38:02 CET)
In this study, a summary of the processes performed on the SPL for recycling, reduction in toxicity and treatment were examined on an industrial and laboratory scale. In writing this research, an attempt has been made to address the useful processes that have taken place in this field. Spent pot lining or SPL is a type of solid waste that is produced in the aluminum production process. After 3 to 8 years, the cathode blocks become problematic and can no longer be used, and need to be replaced due to adverse effects on cell function. SPL is known to be a hazardous waste to nature due to its fluoride and cyanide content. Research has shown that SPL ingredients have destructive and very dangerous effects on human DNA, which is why they are so important to maintain and recycle.
ARTICLE | doi:10.20944/preprints201908.0076.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: dysprosium; activated carbon; spent coffee ground; adsorption
Online: 6 August 2019 (12:23:23 CEST)
This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.
ARTICLE | doi:10.20944/preprints201801.0228.v2
Subject: Chemistry And Materials Science, Metals, Alloys And Metallurgy Keywords: sustainable development, recycling, spent catalysts, zinc, copper
Online: 22 February 2018 (15:46:53 CET)
CuO-ZnO-Al2O3 catalysts are designed for the low-temperature shift conversion in the process of hydrogen and ammonia synthesis gas production. The paper presents the results of research on recovery of copper and zinc from spent catalysts using pyrometallurgical and hydrometallurgical methods. Under reducing conditions, at high temperature, having appropriately selected the composition of the slag, more than 66% of copper in metallic form and about 70% of zinc in the form of ZnO can be extracted from this material. Hydrometallurgical processing of the catalysts was carried out using two leaching solutions: alkaline and acidic. Almost 62% of the zinc contained in the catalysts has been leached to the alkaline solution and about 98% of copper has been leached to the acidic solution. After the hydrometallurgical treatment of the catalysts, insoluble residue was also obtained in the form of pure ZnAl2O4. This compound can be reused to produce catalysts, or it can be processed under reducing conditions at high temperature to recover zinc. The recovery of zinc and copper from such a material is consistent with the policy of sustainable development and helps to reduce the environmental load of stored wastes.
ARTICLE | doi:10.20944/preprints201703.0004.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: fumaric acid; purification; spent sulfite liquor; biorefineries
Online: 1 March 2017 (09:41:31 CET)
Fumaric acid is a chemical building block with many applications, namely in the polymer industry. The fermentative production of fumaric acid from renewable feedstock is a promising and sustainable alternative to petroleum-based chemical synthesis. The use of existing industrial side-streams as raw-material within biorefineries potentially enable production costs competitive against current chemical processes, while preventing the use of refined sugars competing with food and feed uses and avoiding purposely grow crops requiring large areas of arable land. However, most industrial side streams contain a diversity of molecules that will add complexity to the purification of fumaric acid from the fermentation broth. A process for the recovery and purification of fumaric acid from complex fermentation medium containing spent sulfite liquor (SSL) as carbon source was developed and is herein described. A simple two-stage precipitation procedure involving separation unit operations, pH and temperature manipulation and polishing through the removal of contaminants with activated carbon allowed the recovery of fumaric acid with 68.3% recovery yield with specifications meeting the requirements of the polymer industry. Further, process integration opportunities were implemented that allowed minimizing the generation of waste streams containing fumaric acid which enabled increasing the yield to 81.4% while keeping the product specifications.
ARTICLE | doi:10.20944/preprints202207.0129.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: recycled electrode; spent battery; spectroscopic method; cyclic voltammetry
Online: 8 July 2022 (03:31:38 CEST)
The novelty of this study consists in: i) synthesis and characterization of electrode materials recycled from a spent car battery and doped with MnO2 and CuO by the analysis of X-ray diffraction (XRD), Infrared (IR) and Electron Paramagnetic Resonance (EPR) data and ii) the investigation of electrochemical properties of prepared materials in view of new applications as electrode materials for battery. Electron Paramagnetic Resonance (EPR) data indicate that the intensity of the resonance line corresponding to the Cu+2 ion was modified with the increase of the dopant content. The analysis of X-ray Absorption Spectroscopy (XAS) data indicates that by increasing the dopant content there is a process of ordering the oxygen atoms around the lead similar to the PbO2 theoretical model. The electrochemical performances of the recycled and manganese-copper-doped materials are optimized for applications as new anodic electrode for the car battery.
ARTICLE | doi:10.20944/preprints202306.0568.v1
Subject: Chemistry And Materials Science, Electrochemistry Keywords: Corrosion; copper; spent coffee grounds; voltammetry around OCP; EIS
Online: 8 June 2023 (02:25:06 CEST)
This work aims to follow the corrosion behavior of copper in 3 wt% NaCl solution in the presence of a bio-oily extract. Spent coffee grounds (SCG), a highly recyclable and usable biomass - often thrown away and becoming a serious threat to the environment - , has a fraction of oils (12%) that we have opted to use as a corrosion inhibitor for copper. The extraction was carried out using n-hexane as the solvent for the decoction. The oily fraction was analyzed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Potentiodynamic polarization measurements have revealed SCG extract acts as a cathode-type inhibitor for copper in saline media, mainly preventing the diffusion of oxygen molecules toward the substrate. As the extract concentration increased, the inhibition efficiency has improved as well, reaching 95.78 % with 0.6 g/L of SCG extract. The obtained results by electrochemical impedance spectroscopy (EIS) are in accordance with the order of inhibitory efficiency obtained by potentiodynamic polarization. We have found that the SCG extract adsorption process on copper surface is spontaneous and complies with Langmuir isotherm.
REVIEW | doi:10.20944/preprints202212.0043.v1
Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: adsorption; GBV; heavy metals; secondary pollution; spent adsorbent reuse
Online: 2 December 2022 (08:43:18 CET)
Water contamination has intensified over the year as the world's population and industrial activities have grown. Heavy metals (HMs) are amongst the environmental contaminants commonly found in water and wastewater. These include Lead, Manganese, Chromium, Mercury, etc. Various techniques have been used to remediate this environmental challenge and adsorption has proven to be more effective because it is simple to use, excellent efficiency, low cost, possibility to operate in several experimental conditions. Regrettably, this method yields waste materials, which represents a scaling restriction. Furthermore, after the HM has been removed and loaded onto the adsorbent, there is still a question of the fate of the metal-loaded adsorbent. Most of the time these metal loaded adsorbents are discarded in the environment and constitute a secondary pollution. New applications for heavy metals laden have been investigated. This review article presents the various applications that had been investigated to reuse the loaded metal adsorbent. A case study on developing tools for combatting gender-based violence (GBV) has also been discussed.
REVIEW | doi:10.20944/preprints202107.0603.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: brewer’s spent grains; brewing; fungal biovalorization; food waste; malt
Online: 27 July 2021 (11:47:31 CEST)
The beer industry is a major producer of solid waste globally, primarily in the form of brewer’s spent grains (BSG), which due to its low value has historically been diverted to livestock as feed or to landfills as waste. Its high moisture content and chemical composition positions BSG as an ideal candidate for further processing with microbial fermentation, and recent research has focused on filamentous fungi and the ability of some species therein to degrade the predominant recalcitrant cellulolignin components of BSG to produce valuable compounds. Many species have been investigated to biovalorize this waste stream, including those in the genuses Aspergillus, Pennicillium, Rhyzopus, and Trichoderma, which have been used to produce a wide array of highly valuable enzymes and other functional compounds, and to increase the nutritional value of BSG as an animal feed. This review of recent developments in the application of filamentous fungi for the valorization of BSG will discuss the biochemical makeup of BSG, the biological mechanisms underlying fungi’s primacy to this application, and the current applications of fungi in this realm. As the majority of these studies are at lab-scale, the challenges to scale-up and more widespread application and will be discussed as well.
REVIEW | doi:10.20944/preprints202305.2255.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: recycling of spent coffee grounds; lactic acid production; polylactic acid
Online: 31 May 2023 (13:19:57 CEST)
Coffee is one of the most popular beverages in the world. Annual coffee consumption continues to increase, but at the same time, it generates a large amount of spent coffee grounds from the brewing process, that arises environmental problems. An appropriate solution to manage these spent coffee grounds becomes crucial. Our project aims to discuss the feasibility of utilizing the spent coffee ground to synthesize polylactic acid as a recycling application for spent coffee ground. This paper will discuss the properties and potential recycling applications of spent coffee grounds, the brief production process of polylactic acid, and the potential process for converting spent coffee ground to lactic acid. From our review, it is feasible to utilize spend coffee ground as the primary sources for lactic acid production by bacteria fermentation, and further produce bioplastics, polylactic acids by ring-opening polymerization. Possible ways to improve the yield and corresponding cost analysis are also discussed.
ARTICLE | doi:10.20944/preprints202305.1210.v1
Subject: Chemistry And Materials Science, Electrochemistry Keywords: recycled plates from spent car battery: electrodes; spectroscopic method; cyclic voltammetry
Online: 17 May 2023 (08:34:21 CEST)
This paper proposes the recycling of plates from spent car batteries by the melt quenching method and the incorporation of NiO or Co3O4 contents in order to improve the electrochemical performance of new materials for applications as electrodes on batteries. The analysis of X - ray diffractograms indicates the gradual decrease of the sulfated crystalline phases, respectively 4PbO•PbSO4 and PbO•PbSO4 phases until their disappearance for higher dopant concentrations. IR data show a decreasing trend in the intensity of the bands assigned to sulfate ions and a conversion of [PbO3] pyramidal units into [PbO4] tetrahedral units by doping with high dopant levels yielding to the formation of the PbO2 crystalline phase. The EPR data indicate three resonance lines centered on the gyromagnetic factor, g ~ 2, 2.2 and 8, which are dependent on the NiO level. The first two resonance lines are assigned to nickel ions in higher oxidation states and the last signal centered at g ~ 8 corresponds to nickel metal nanoparticles. This compositional evolution can be explained by considering a process of drastic reduction of nickel ions in oxidation states superior to metallic nickel. The linewidth and the intensity of resonance lines situated at about g ~ 2, 2.17, 4.22 and 7.8 corresponding to the Co+2 ions from EPR spectra depend very strongly on the Co3O4 concentration. The best reversibility of the cyclic voltammograms was highlighted for the samples with x = 8 mol% NiO and 10 mol% Co3O4, which are recommended as suitable in applications as electrode for renewable batteries.
ARTICLE | doi:10.20944/preprints201704.0050.v1
Subject: Engineering, Energy And Fuel Technology Keywords: nuclear; reactor; spent fuel; P&T; innovation strategy; molten salt reactor
Online: 10 April 2017 (06:20:11 CEST)
The current generation of nuclear reactors are evolutionary in design, mostly based on the technology originally designed to power submarines, and dominated by Light Water Reactors. The aims of the GenIV consortium are driven by sustainability, safety and reliability, economics, and proliferation resistance. The aims are extended here to encompass the ultimate and universal vision for strategic development of energy production, the ‘perpetuum mobile’ – at least as close as possible. We propose to rethink nuclear reactor design with the mission to develop a system which uses no fresh resources and produces no fresh waste during operation as well as generates power safe and reliably in economic way. The results of the innovative simulations presented here demonstrate that, from a theoretical perspective, it is feasible to fulfil the mission through the reuse of spent nuclear fuel from currently operating reactors as the fuel for a new reactor. The produced waste is less burdensome than current spent nuclear fuel which is used as feed to the system. However, safety, reliability and operational economics will need to be demonstrated to create the basis for the long term success of nuclear reactors as a major carbon free, sustainable, and applied highly reliable energy source.
ARTICLE | doi:10.20944/preprints201908.0093.v2
Subject: Chemistry And Materials Science, Food Chemistry Keywords: spent coffee grounds; polyphenols; extraction; subcritical fluid; activated carbon; methylene blue; adsorption.
Online: 20 September 2019 (10:23:51 CEST)
A valorization process of spent coffee grounds (SCG) was studied. Thus, a two-stage process, a stage of extraction of the polyphenols and a stage of obtaining activated carbon (AC) by a carbonization process, was performed. The extraction was carried out with a hydro-alcoholic solution in a pressure reactor, modifying time and temperature. To optimize the extraction of polyphenols, a two-level factorial design with three replications at the central values was used. The best results were obtained by performing the extraction at 80 °C during 30 min, using a mixture of EtOH:H2O 1:1 (v/v) as extraction solution. Caffeine and chlorogenic acid were the most abundant compounds in the analyzed extracts, ranging from 0.09 to 4.8 mg∙g-1 and 0.06 to 9.7 mg∙g-1, respectively. The precursor obtained in the extraction stage were transformed into AC. An experimental design was realized in order to analyze the influence of different variables in the AC obtained process (reaction time and amount of potassium hydroxide used). Actived carbons with BET specific surface (SBET) comprised between 1600 m2∙g-1 and 2330 m2∙g-1 had a microporous surface. Under the optimum conditions, the obtained AC presented a maximum adsorption capacity of methylene blue (qm) between 411 mg∙g-1 and 813 mg∙g-1.
ARTICLE | doi:10.20944/preprints202307.1215.v1
Subject: Biology And Life Sciences, Horticulture Keywords: spent mushroom compost (SMC) substrate; cultivation years; physicochemical properties; enzyme activities; microbial community
Online: 18 July 2023 (11:04:11 CEST)
Spent mushroom compost (SMC) substrates are commonly used as growth media for greenhouse crops and horticulture production. This study aimed to investigate the responses of physiochemical soil properties, enzyme activities, and microbial community compositions to different cultivation durations and SMC soil treatments on tomatoes (Solanum lycopersicum L.) grown in plastic greenhouses on the Loess Plateau, China. The experiment included treatments: Two control treatments of non-planting SMC substrates (Sub CK) and continuous mono-cropping soil (Soil CK), and SMC substrate and the surrounding soil after planting at 1, 3, and 7 years. The results revealed that the SMC substrates had higher contents of major nutrients (e.g., total N and total P) than the surrounding soil treatments. The physicochemical soil properties and soil enzyme activities of the SMC substrates were significantly decreased with longer cultivation duration. Microbial alpha-diversity was higher in the SMC substrates regardless of cultivation duration than the control treatment (soil CK and substrate CK). Interestingly, following several years of tomato cultivation, the compositions of bacterial communities had more similarities with fungal communities in both the SMC substrates and surrounding soils. It was observed that many beneficial microbes, such as bacteria of the Deinococcus-Thermus, Halanaerobiaeota, and Nitrospirae phyla, and the fungi of the Basidiomycota, Mortierellomycota, and Chytridiomycota phyla were enriched in the SMC substrates. The pathogenic bacterial genus Sphingomonas and fungal genus Fusarium were abundant in the Soil CK treatment, while the potentially beneficial bacterial genera Saccharimonadales, Gaiella, Bacillus, and fungal genera Thermomyces, Kernia, and Mortierella were abundant in both the SMC substrate and surrounding soil. This study demonstrated that agro-based SMC substrates were a suitable growth media for a new grooved cultivation system.
ARTICLE | doi:10.20944/preprints202305.1800.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: Brewers’ spent grain; biomass conversion technologies; prospective study; technology implementation.; waste to energy
Online: 25 May 2023 (10:31:18 CEST)
Brewers’ spent grain (BSG) is an important waste produced in beer companies with a high po-tential to be transformed into commercial by-products. The present paper reports a forecasting technology study with the aid of bibliographic review and patent analysis tools aiming to in-vestigate the maturity of certain technologies, considering the use of BSG on a closed-loop bio-refinery and circular bioeconomy concept integrated into a brewery. To evaluate the possibili-ties of production of high-added value products in Brazil, it was presented an overview of BSG’s scientific, technological, and marketing products and applications. The comparison between numbers of articles versus patents shows that the solutions proposed by research articles are not being transformed into maturated viable technologies. The results suggest that there is a gap between the scientific research in the institutions and their applications in industry, which lead to the destination of the BSG for more economically attractive investments when compared to research in Brazil. Ultimately, from the carried-out analysis, it was possible to propose a brew-ing process connected to the biorefinery system, showing the possibility to the newly arising brewery industries.
REVIEW | doi:10.20944/preprints202212.0138.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Spent coffee grounds; SCG Briquettes; SCG Biodiesel; Caffeine; Residual Oil; Irregular Particle Size
Online: 8 December 2022 (01:42:06 CET)
Coffee is regarded as the highly consumed beverage throughout the world and has established a key spot in the world economy as an important commodity for trading. In general, they are produced by brewing their roasted and ground beans, which release aromatic coffee; as well as produce an equivalent amount of spent coffee grounds (SCG). Previously, they were discarded as wastes or used as natural pest repellent or garden fertilizer; however, in recent times, are valorized into biofuels owing to their high calorific value. In fact, SCG briquettes have gained wide attention for supplying energy renewably, especially to the rising energy demand; and also have been identified as an effective measure to reduce their pollution. With this in mind, this present chapter focuses on reviewing the availability and chemistry involved in these SCG wastes, pre-treatments and preparations required for their briquetting, compacting techniques followed, and fuel characteristics of their briquettes, from various available works of literature. Here, their availability showcases the amount of SCG wastes generated with respect to time and consumption, wherein understanding their chemistry helps in deciding the pre-treatments necessary for their briquetting. Meanwhile, preparation techniques briefs about the necessary pre-treatments undertaken before compaction by different researchers; and the fuel characteristics define the physicochemical and mechanical properties of their briquettes, developed using various compaction methods. Besides, combustion behaviors of these briquettes are explained in terms of their burning characteristics and emission levels, as reported in literatures; which help in deciding their suitability as a replacement for existing fossil coal. Eventually, all the reported data were in accordance with their permissible standards and suggested these SCG as a highly renewable solid biofuel.
ARTICLE | doi:10.20944/preprints202112.0064.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: spent fluid catalytic cracking catalyst; waste slag; leaching; lanthanum oxide; rare earths recovery
Online: 6 December 2021 (12:04:43 CET)
An laboratory procedure has been developed to obtain lanthanum oxide from spent fluid catalytic cracking catalyst, commonly used in the cracking the heavy crude oil process. Two different spent fluid catalytic cracking catalysts, which are mainly formed by silica and alumina, and a certain amount of rare earths were leached under several conditions to recover the rare earth from the solids waste. Subsequently, liquid phases were subjected to a liquid-liquid extraction process, and lanthanum was quantitatively stripped using oxalic acid to obtain the corresponding lanthanum oxalates. After the corresponding thermal treatment, these solids were transformed into lanthanum oxide. Both, lanthanum oxalates and oxides solids have been characterized by wide techniques in order to investigate the purity of the phases.
ARTICLE | doi:10.20944/preprints202308.0791.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: hydrogen sulphide; adsorption; fixed-bed column; modelling; spent alkaline batteries; Zn-Mn-oxides mixture
Online: 9 August 2023 (16:23:15 CEST)
Breakthrough curves for the adsorption of H2S using a metal-oxides mixture were predicted using the Bohart-Adams model of fixed bed adsorption. This mixture (ZnMn2O4+ZnO+Mn2O3) came from the processing of an urban waste as spent alkaline batteries were. The H2S adsorption experiments were carried out in a fixed-bed column at 20º C, and under various experimental conditions: gas flow rate, inlet H2S concentration and adsorbent dosage. Curves predicted by the model matched well with experimental data, providing data for the possible scale-up of the system. At the various experimental variables, the efficiency of the column, were also provided in the work. This investigation demonstrated the usefulness of a waste material, like spent alkaline batteries, to provide an adsorbent material to mitigate the problem of the presence of this harmful gas.
ARTICLE | doi:10.20944/preprints202310.0308.v1
Subject: Chemistry And Materials Science, Chemical Engineering Keywords: activated carbon; biomass; carbon composites; spent coffee; Aloe-Vera; corncob; zinc oxide, H2S, hydrogen sulfide, adsorption
Online: 6 October 2023 (05:05:45 CEST)
Biomass exploitation is a global trend due to the circular economy and the environmentally friendly spirit. Numerous applications are now based on the use of biomass derived products. Hydrogen sulfide (H2S) is a highly toxic and environmentally hazardous gas, which emitted from various processes. Thus, the efficient removal of this toxic hazardous gas following cost effective processes is an essential requirement. In this study, we present the synthesis and characterization of biomass-derived activated-carbon/zinc-oxide (ZnO@AC) composites from different biomass sources as potential candidates for H2S sorption. The synthesis involved a facile method for activated carbon production via pyrolysis and chemical activation of biomass precursors (spent coffee, Aloe-Vera waste leaves, and corncob). Activated carbon production was followed by the incorporation of zinc oxide nanoparticles into the porous carbon matrix using a simple melt impregnation method. The synthesized ZnO@AC composites were characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and nitrogen porosimetry. The H2S removal performance of the ZnO@AC composites was evaluated through sorption experiments using a handmade apparatus. Our findings demonstrate that the Aloe-Vera, Spent-coffee, and Corncob derived composites exhibit superior H2S sorption capacity up to 106 mgH2S/gads., 66 mgH2S/gads., and 47 mgH2S/gads. respectively.
DATA DESCRIPTOR | doi:10.20944/preprints201906.0189.v1
Subject: Engineering, Energy And Fuel Technology Keywords: mushrooms; mushroom spent compost; renewable energy; biochar; biomass valorization; torrefaction; fuel properties; proximate analysis; carbon sequestration
Online: 20 June 2019 (03:40:36 CEST)
Mushroom production in Poland is an important and dynamically developing element of diverse agriculture. Mushroom spent compost (MSC) is major waste generated during production, i.e., MSC: mushrooms is ~5:1. To date, the main use of MSC is soil application as organic fertilizer. To date, several methods of MSC treatment have been researched and developed including production of compost, bioethanol, biogas, enzyme lactase, xylo-saccharides, and hydrogen. Torrefaction may be considered a novel approach for biomass valorization. Thus, we are pioneering the potential use of MSC valorization via torrefaction. We explored valorizing the waste biomass of MSC via thermal treatment – torrefaction (‘roasting’) to produce biochar with improved fuel properties. Here for the first time, we examined and summarized the MSC torrefaction thermogravimetric analyses, fuel properties data of raw biomass of MSC and biochars generated from MSC via torrefaction. The effects of torrefaction temperature (200~300 °C), process time (20~60 min), on fuel properties of the resulting biochars were summarized. The dataset contains results of thermogravimetric analysis (TGA) as well as proximate analyses of MSC and generated biochars. The presented data are useful in determining MSC torrefaction reaction kinetics, activation energy and to further techno-economical modeling of the feasibility of MSC valorization via torrefaction. MSC torrefaction could be exploited as part of valorization resulting from a synergy between an intensive mushroom production with the efficient production of high-quality renewable fuel.
ARTICLE | doi:10.20944/preprints202307.1934.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: shelf life; biomass valorization; spent coffee; activated carbon; thymol; chitosan; poly-vinyl-alcohol; nanohybrids; control release; active coatings; bananas preservation
Online: 27 July 2023 (12:12:30 CEST)
Food waste disposal to landfills practice contributes to greenhouse problem due to the emission of gases such as methane to the atmosphere. Shelf-life extension of food products and further valorization of food wastes such as the conversion to activated carbon are tested nowadays as alternative techniques. The development and use of biobased active coatings against food oxidation/bacterial deterioration is an environmentally friendly technique. In this study, a novel food active coating was successfully developed based on a chitosan (CS)/poly-vinyl alcohol (PVOH) matrix activated with a nanohybrid of natural thymol (TO) adsorbed in activated carbon (AC) derived from spent coffee. The results shown that, compared to the pure CS/PVOH polymeric matrix, the coating with 15% wt. TO@AC nanohybrid concentration achieved +23.5 % Young’s modulus value, +20.1% ultimate strength value, increased barrier of +50.2% for water and +74.0 % for oxygen, +69.0% antioxidant activity, increased antibacterial activity of +5.5% against Escherichia coli, +17.8% against Salmonella enterica, +42.5% against Staphylococcus aureus, and +2.5% against Listeria monocytogenes. A visual evaluation of this coating shown a delay to fresh bananas enzymatic browning and significantly decrease their weight loss. This indicates that it could be potentially used to extend the shelf-life of fresh fruits.
ARTICLE | doi:10.20944/preprints202306.1043.v1
Subject: Engineering, Other Keywords: brewers’ spent grain; biomethane production kinetics; methane fermentation; biogas; anaerobic digestion; iron powder; Fe; lime; Ca(OH)2; porous ceramic.
Online: 14 June 2023 (10:13:34 CEST)
The process of anaerobic digestion used for methane production can be enhanced by incorporating stimulating materials. The effects of these materials are dependent on various factors including the processed substrate, process conditions, and the type and amount of the stimulating material used. As part of the study, three different stimulating materials - iron powder, lime, and milled porous ceramic - were added to the 30-day anaerobic digestion of the brewer's spent grain to improve its performance. Different doses ranging from 0.2 to 2.3 gTS×L-1 were tested, and methane production kinetics were determined using the first-order model. The results showed that the methane yield ranged from 281.4±8.0 to 326.1±9.3 ml×gVS-1, while substrate biodegradation ranged from 56.0±1.6 to 68.1±0.7%. The addition of lime reduced methane yield at almost all doses by -6.7% to -3.3%, while the addition of iron powder increased methane yield from 0.8% to 9.8%. The addition of ceramic powder resulted in a methane yield change ranging from -2.6% to 4.6%. These findings suggest that the use of stimulating materials should be approached with caution, as even slight changes in the amount used can impact methane production.
ARTICLE | doi:10.20944/preprints201907.0212.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: waste to energy; mushroom spent compost, renewable energy; biochar; biomass valorization; torrefaction; activation energy; fuel properties; proximate analysis; carbon sequestration
Online: 18 July 2019 (10:00:34 CEST)
Poland is the 3rdproducer of mushrooms in the world. Mushroom production in Poland accounts for nearly 25% of the total production in the EU, and it is still growing. One type of waste generated during mushroom production is mushroom spent compost (MSC), with a 5:1 (MSC: mushrooms) production rate. We investigated valorizing the MSC to produce fuel via torrefaction (‘roasting’, a.k.a. low-temperature pyrolysis). Specifically, we developed models for the MSC torrefaction kinetics using thermogravimetric analyses (TGA) and the effects of torrefaction temperature (200~300 °C) and process duration time (20~60 min) on the resulting biochar (fuel) properties. The estimated activation energy value of MSC torrefaction was 22.3 kJ.mol-1. The highest higher heating value(HHV) = 17.9 MJ.kg-1d.m. was found for 280 °C (60 min torrefaction time). The temperature of torrefaction significantly (p<0.05) increased the HHVfor constant process duration. The torrefaction duration time significantly (p<0.05) increased the HHVfor 220 °C and decreased HHVfor 300 °C. The highest mass yield 98.5% was found for 220 °C (60 min), while the highest energy yield was found for 280 °C (60 min). In addition, estimations of the value (€132.3·Mg-1d.m. or 27.7 €·Mg-1w.m) and quantity of resulting biochar (from torrefied MSC with 65.3% moisture content) were made based on the 280°C (60 min) torrefaction variant, assuming the price of commercially available coal fuel. We have shown a concept for an alternative utilization of abundant biowaste (MSC). The initial economic evaluation showed that MSC torrefaction might be profitable. This research provides a basis for alternative use of an abundant biowaste and can help charting improved, sustainable mushroom production.
ARTICLE | doi:10.20944/preprints201904.0153.v1
Subject: Engineering, Energy And Fuel Technology Keywords: nuclear waste isolation; horizontal disposal drillholes; directional drilling; engineered barrier system, spent nuclear fuel, waste repository, geologic disposal; high level waste
Online: 13 April 2019 (05:11:28 CEST)
Spent nuclear fuel and high-level radioactive waste can be disposed in deep horizontal drillholes in sedimentary, metamorphic, or igneous rocks. Horizontal drillhole disposal has safety, operational, and economic benefits: The repository is deep in the brine-saturated zone far below aquifers in a reducing environment of formations that can be shown to have been isolated from the surface for millions of years; its depth provides safety against inadvertent intrusion, earth¬quakes, and near-surface perturbations; it can be placed close to the reactors and interim storage facilities, minimizing transportation; disposal costs per ton of waste can be kept substantially lower than for mined repositories by its smaller size, reduced infrastructure needs, and staged imple¬mentation; and, if desired, the waste could be retrieved using “fishing” technology. In the proposed disposal concept, corrosion-resistant canisters containing unmodified fuel assemblies from commercial reactors would be placed end-to-end in up to 50 cm diameter horizontal drill¬holes, a configuration that reduces mechanical stresses and keeps the temperatures below the boiling point of the brine. Other high-level wastes, such as capsules containing 137Cs and 90Sr, can be disposed in small-diameter drillholes. We provide an overview of this novel disposal concept and its technology, discuss some of its safety aspects, and compare it to mined repositories and the deep vertical borehole disposal concept.
ARTICLE | doi:10.20944/preprints202306.0763.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Mycogone perniciosa; Bacillus subtilis; industrial Bacillus strains; microbiocontrol; antifungal activity; producer strains; biological efficacy; multirecycled spent mushroom substrates; multirecycled SMS aqueous extracts; submerged multibiorecycled biologics
Online: 12 June 2023 (04:56:57 CEST)
Microbiocontrol of Mycogone perniciosa is focused on casing soil antagonists use. Since no industrial producer strains of polyfunctional biologics were used in previous studies, research goal was to characterize Bacillus subtilis B-10 and M-22 effect on mycopathogen and reveal its control possibilities. Interactions between producer strains and M. perniciosa were evaluated using well method and spraying. Mycoparasite colony area and its lysis zone were determined. Biological efficacy was characterized by lysis zone proportion in total area occupied by the micromycete mycelium. Statistical processing included W-test, ANOVA, means (M) and standard errors (±SEM) calculation. The significance was assessed by t-test. M. perniciosa development suppressing by producer strains was established, indicates a prolonged B-10 and M-22 effect on mycopathogen. High biological efficacy of both strains at the early stages of mycopathogen development by introducing into the wells and spraying was shown: B-10 – 50.9–99.6 % and M-22 – 57.5–99.2 % respectively (p ≤ 0.05). Significant differences between producer strains were not revealed, although during the first exposure day to developed M. perniciosa colonies M-22 has shown greater activity. Preventive treatment high efficiency when producer strains completely suppressed mycoparasite development, permit recommending them both to introduce when preparing casing for M. perniciosa control.