Abstract: Liquid fuels obtained from CO₂ and green hydrogen (i.e. e-fuels) are powerful tools for decarbonization of the economy. Improvements provided by Process Intensification in the existing conventional reactors aim toward a decrease in energy consumption, higher yield and more compact and sure processes. This review describes the advances in the production of methanol, dimethyl ether and hydrocarbons by Fischer-Tropsch using different tools of Process Intensification, mainly membrane reactors, sorption enhanced reactors and structured reactors. Due to the environmental interest, the review on methanol and dimethyl ether synthesis is mainly devoted to systems based in a feed with CO₂+H₂, while for Fischer-Tropsch the use of syngas (CO+H₂) is also considered. Both mathematical models and experimental results are discussed. Achievements in the improvement of catalytic reactor performance are described.

Abstract: This study systematically investigates the combustion behavior and kinetic characteristics of oil shale semi-coke. Thermogravimetric analysis (TGA) experiments, combined with both model-free and model-based methods, were used to explore the thermal characteristics, kinetic parameters, and reaction mechanisms of the combustion process. The results show that the combustion process of oil shale semi-coke can be divided into three stages: a low-temperature stage (50-310 °C), a mid-temperature stage (310-670 °C), and a high-temperature stage (670-950 °C). The mid-temperature stage is the core of the combustion process, accounting for approximately 28%-37% of the total mass loss, with the released energy concentrated and exhibiting significant thermal chemical activity. Kinetic parameters calculated using the model-free methods (OFW and KAS) and the model-based Coats-Redfern method reveal that the activation energy gradually increases with the conversion rate, indicating a multi-step reaction characteristic of the combustion process. The F2-R3-F2 model, with its segmented mechanism (boundary layer + second-order reaction), better fits the physicochemical changes during semi-coke combustion, and the analysis of mineral phase transformations is more reasonable. Therefore, the F2-R3-F2 model is identified as the optimal model in this study and provides a scientific basis for the optimization of oil shale semi-coke combustion processes. Furthermore, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were conducted on oil shale semi-coke samples before and after combustion to study the changes in the combustion residues. SEM images show that after combustion, the surface of the semi-coke sample exhibits a large number of irregular holes, with increased pore size and a honeycomb-like structure, indicating that the carbonaceous components were oxidized and decomposed during combustion, forming a porous structure. XRD analysis shows that the characteristic peaks of quartz (Q) are enhanced after combustion, while those of calcite (C) and pyrite (P) are weakened, suggesting that the mineral components underwent decomposition and transformation during combustion, particularly the decomposition of calcite into CO₂ at high temperatures. Infrared spectroscopy (IR) analysis reveals that after combustion, the amount of hydrocarbons in the semi-coke decreases, while aromatic compounds and incompletely decomposed organic materials are retained, further confirming the changes in organic matter during pyrolysis.

Abstract: In this study, a 5 m×1 m×0.04 m sand filling model was constructed to simulate Lukqin thick oil reservoir, and the development rules of water flooding and foam flooding were systematically analyzed. The results show that the recovery rate of water flooding is only 30% due to the imbalance of mobility ratio and gas channeling. By integrating electrical resistivity tomography (ERT) with HSV (Hue-Saturation-Value) color mapping, this study pioneers the first visualization of foam migration in meter-scale heterogeneous reservoirs (5 m × 1 m × 0.04 m) with a spatial resolution of ≤0.5 cm. This surpasses the limitations of conventional CT scanning (typical resolution ≥2 cm) and X-ray tomography (cost: 500–800 per scan), offering a 30% reduction in monitoring costs. The proposed 5 m × 1 m × 0.04 m sandpack model reveals that foam flooding enhances oil recovery by 15–20% via synergistic mechanisms of dynamic high-permeability channel plugging (governed by S=0.7C0.6kr−0.28) and mobility ratio optimization, surpassing the 30% recovery limit of conventional water flooding. The main controlling factors of gas channeling (injection speed, foam quality, permeability heterogeneity) are revealed, and the optimization of injection parameters, improvement of foam formulation, combined with numerical simulation and other synergistic techniques are proposed. The proposed large-scale physical simulation methods advance the understanding of foam flooding mechanisms in meter-scale heterogeneous reservoirs, directly guiding the optimization of air foam flooding operations in the Lukqin oilfield.

Abstract: Agro-waste-derived biochar is a valuable material suitable in various applications, offering benefits in green chemistry, circular economy, and sustainability. This study provides an overview of its suitability and efficiency in addressing wastewater challenges. This review stands out for its comprehensive evaluation of biochar's potential within the context of green chemistry principles, circular economy practices, and sustainable development goals. Agro-waste-derived biochar possesses desirable properties such as a high surface area, porous structure, and abundant moieties, effective adsorption of various pollutants. Adsorption mechanisms involving physical adsorption/ion exchange, surface complexation, and electrostatic interactions were also reviewed. Moreover, using agro-waste for biochar production aligns with circular economy principles by converting waste into a valuable resource. Furthermore, it offers a sustainable alternative to conventional adsorbents while reducing environmental impacts associated with waste disposal. Besides, applying biochar in wastewater treatment contributes to green chemistry by promoting environmentally friendly materials and processes. Overall, the use of agro-waste-derived biochar in wastewater treatments has significant potential for achieving multiple sustainability goals, including pollution control, resource recovery, and the advancement of green and circular economy principles. However, further research is necessary to explore optimization strategies, scale-up challenges, and the long-term performance of agro-waste derived biochar in diverse wastewater treatment scenarios.

Abstract: The transition of the chemical industry towards the utilization of feedstocks based on renewable energies results in a more dynamic process behavior. Advanced mathematical methods are a key factor to handle this complexity. In this contribution, methanol synthesis from hydrogen, carbon dioxide and carbon monoxide is investigated as promising power-2-X technology. Optimal experimental design is used to recalibrate an existing mechanistic kinetic model. Subsequently, the most uncertain sub-model, namely the reversible catalyst dynamics, is partially replaced by neural networks. Several architectures were evaluated, and optimal experimental design was applied to enhance the performance of a chosen architecture. All experiments were realized in an experimental setup able to acquire time-resolved data. A commercial CuO/ZnO/Al₂O₃ catalyst was used in a well-mixed Berty type reactor. The combination of optimal experimental design with hybrid modeling led to an improved quality of the kinetic model needed for process control and optimization.

Abstract: Novel aspects in drive train lubrication are coming into the focus of future technologies covering new materials, accompagnied by digital and ecological aspects. Cradle to cradle (C2C) and waste to cradle (W2C) are offering broad sources of chemicals derived from greens out of the bio-cycle, obtained by decentralized farming. This leads to the fact, that valuable raw materials are accessible from everywhere. Chemicals derived from the bio-life cycle are in tendence rich in oxygen (nitrogen) and as such polar with a general affinity to water with high degree of sustainability and superior CO2 footprint. Lubricants as been used today in contrast are derivatives of fossils with low oxygen content and low affinity to water, poor in sustainability and CO2 footprint. As all life cycle assessments are based on the current lubrication technology, the efforts are high (low technical readiness level) for assessing bio-life cycle based lubricants with respect to their suitability in the technical life cycle, based on test rigs. However, machine learning (ML) techniques could reveal the relevant chemical predictors that are needed to pass a life cycle test rig. Such predictors are available from numerous test rig results assessing traditional lubricants and could be taken for the prediction of the novel bio-life based chemicals. Such concepts have been published recently (Literature). Novel sensor concepts could assist by early predicting failures. As such, the use of ML is inevitable to predict their usefulness in drive train. Coatings may serve as adjuvants for novel C2C (W2C) based lubrication. So far, to open the gate for bio-life based C2C (W2C) chemistry brings up a stringent need for novel sensor concepts in junction with ML. The upcoming EV drive train technology is reaching out for non water based fluids with high heat capacity and thermal conductivity for the electrical segment on one side and low viscous lubricants for the mechanical part on the other. Novel, ML based technologies in C2C (W2C) chemistry could couple both parts into one, as a vision for decentralized sustainable and low CO2 footprint technologies.

Abstract: With the rapid development of renewable energy, efficient and stable energy storage technologies have become a research focus in the energy sector. Aqueous zinc-ion batteries (AZIBs) hold great promise for electrochemical energy storage due to their high safety, abundant zinc resources, high theoretical specific capacity, and low redox potential. However, AZIBs still face challenges such as low electronic conductivity, sluggish ion migration kinetics, zinc dendrite growth, and side reactions, which severely limit their practical applications. To address the issues of the large zinc-ion radius and the restricted interlayer spacing of vanadium oxides, this study proposes an innovative in-situ intercalation polyaniline (PANI) molecular modification strategy. A flower-like organic-inorganic hybrid material, PANI-V2O5 , is successfully synthesized via a synchronous oxidative polymerization method. This strategy effectively regulates the interlayer spacing of vanadium oxides without introducing inert cations, significantly enhancing the material's conductivity and structural stability while accelerating zinc-ion diffusion kinetics. Electrochemical tests demonstrate that PANI-V2O5 exhibits a high specific capacity of up to 450 mAh·g⁻¹ at a current density of 0.1 A·g⁻¹ and retains 96.7% of its capacity after 300 cycles at 1 A·g⁻¹, showcasing excellent cycling stability and rate performance. This study provides new insights into the design of high-performance cathode materials for zinc-ion batteries and lays a theoretical and experimental foundation for the development of efficient and stable energy storage systems in the future.

Abstract: Although bioleaching of secondary copper sulfides has been industrialized for decades, application of bioleaching to chalcopyrite is still under development due to low leaching rate. The effect of contact microbes on chalcopyrite leaching remains unclear due to the technical challenges in separating the contact (sessile micro-organisms) and the non-contact (planktonic micro-organisms) processes. Chalcopyrite bioleaching experiments were conducted using a novel device which stabilized the redox potential and distinguished between the microbial contact and non-contact effects. The contribution of the microbial “contact mechanism” in chalcopyrite leaching was quantified considering different redox potentials, compared to the “non-contact mechanism”. Based on the copper leaching kinetics and morphology of the leaching residue, it was demonstrated that the leaching rate of chalcopyrite was significantly influenced by the redox potential (850 mV > 650 mV > 750 mV). At each redox potential, the chalcopyrite leaching rate was higher with the presence of sessile microbes than without sessile microbes. Analysis of the leached chalcopyrite surface using time of flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectrometer (XPS) revealed the formation of polysulfide and elemental sulfur at the surface. However, the elemental sulfur content at the leach residue surface with the contact microorganisms was less than one-third of the surface elemental sulfur content in the absence of microorganisms. The sulfur-oxidizing microbes preferred sessile acidophiles at the chalcopyrite surface, thus played an important role in degrading the sulfur passivation layer. In chalcopyrite bioleaching, the “contact mechanism” was primarily explained by sulfur-oxidizing bacteria promoting chalcopyrite oxidation through the removal of sulfur intermediates, while the “non-contact mechanism” was explained by ferrous-oxidizing microbes influencing the redox potential.

Abstract:

The increasing demand for bio-based chemicals and sustainable materials has placed biomass-derived lactic acid in the spotlight as a key building block for biodegradable polylactic acid (PLA). Perennial ryegrass (Lolium perenne) is a promising feedstock due to its high dry matter (DM) yield, adaptability, and widespread agricultural use. This study investigates an integrated lactic acid–silage cascade process, focusing on how pH regulation, harvest timing, and biomass characteristics influence lactic acid production while maintaining agronomic efficiency. The results highlighted the crucial role of pH management and silage duration in optimizing lactic acid production. A silage period of 21 days was found to be optimal, as peak lactic acid yields were consistently observed at this stage. Maintaining a pH range of 4.5 to 6 proved essential for stabilizing fermentation, with citrate buffering at pH 6 leading to the highest lactic acid yields and minimizing undesirable by-products. Harvest timing also significantly affected lactic acid yield per hectare. While later harvesting increased total DM yield, it led to a decline in lactic acid concentration per kg DM. Tetraploid ryegrass (Explosion) maintained stable lactic acid yields due to higher biomass accumulation, whereas diploid varieties (Honroso) experienced a net reduction. From an agronomic perspective, optimizing harvest timing and variety selection is key to balancing biomass yield and fermentation efficiency. While tetraploid varieties offer greater flexibility, diploid varieties require precise harvest timing to avoid losses. These findings contribute to sustainable forage management, improving lactic acid production, silage efficiency, and agricultural resource use.

Abstract: In the process of acidizing operation, especially in ultra-high temperature wells, metal components such as wellbore tubing and surface equipment are severely corroded by acid fluids, leading to operational challenges in oilfield production. At present, the ad-dition of corrosion inhibitors is one of the most effective methods to mitigate metal corrosion. Pyridine residues, quinoline quaternary ammonium salts, aldehyde ketone amine condensates, acetylenic methyl ammonia and imidazoline corrosion inhibitors have been widely studied in the industry. Among them quaternary ammonium salts are widely used in oilfield production due to their excellent corrosion resistance, low toxicity and good water solubility. However, their limited heat resistance makes them unsuitable for ultra-deep exploration wells or scientific research wells. This study fo-cuses on N-heterocyclic quaternary ammonium salt-based corrosion inhibitors (alkyl quinolinium quaternary ammonium salts), which can withstand temperatures up to 200°C, meeting the requirements of ultra-high temperature wells.

Abstract: To investigate the specific performance enhancement of oilfield surfactants by using sodium p-aminobenzenesulfonate as a connecting group, cationic surfactant N,N-dimethyl-N-(oxiran-2-ylmethyl)dodecan-1-aminium (DDPA) and zwitterionic gemini surfactant 4-[bis(3-(dodecyldimethylamino)-2-hydroxypropyl)amino]benzenesulfonate sodium (DDBS) were synthesized. The oil recovery performance of these surfactants was compared, revealing that DDBS outperforms DDPA in thermal stability, wettability, adsorption, and resistance to temperature and salinity variations, as well as surface/interface activity, except for emulsification. Core flooding experiments, simulating the conditions of the Xinjiang oilfield, demonstrated that DDBS can achieve the same enhanced oil recovery effect at a concentration that is 1/15 of that of DDPA. DDBS and DDPA can incrementally improve recovery rates by 7.9% and 8.5%. Furthermore, the synergistic formulation of DDBS with sodium dodecylbenzenesulfonate (SDS) significantly optimized performance, achieving a reduction in interfacial tension to 0.0301 mN m^(-1). This study provides a research and data foundation for the application of new surfactants in petroleum extraction.

Abstract: The production of hydrocarbon-based biofuels has been the target of intense research worldwide. In this context, the core goal of the present work was to investigate the use of mesopore-rich activated carbons (ACs) as support for sulfided Mo-based catalysts intended for the hydroprocessing of lipidic feedstocks. Key issues of the work were that: unlike traditional inorganic supports, ACs are highly resistant to hydrolysis, which is a very important aspect in the hydroprocessing of lipidic feedstocks because water is abundantly produced during the process; the porosity of ACs can be tailored to give rise to a high mesopore content, which are important for improving the access of bulky triglyceride molecules to metallic active sites located inside the pores network. A systematic study on the effects of the preparation conditions on the properties and performance of the obtained catalysts was carried out. The highest hydrodeoxygenation (HDO) activity was verified for the catalyst prepared through sequential deposition of Mo and Ni by wet impregnation. The prepared catalyst presented better performance for coconut oil HDO than an industrial sulfided NiMo/Al2O3 catalyst. Furthermore, the prepared catalysts presented good stability, provided the sulfidation degree was kept high. The obtained results evidenced that ACs have great potential to replace inorganic supports in sulfided Mo-based catalysts.

Abstract:

Water adsorbent to dehydrate water ethanol mixture was synthesized from spent bleaching earth (SBE) using modified fusion method. The SBE was regenerated by heat at 750C. Alumina (Al2O3) was added to SBE with 80 g alumina per 100 g SBE. Potassium hydroxide (KOH) was added to SBE with stoichiometry ratio of KOH: SBE of 1.1 then mixed and fused at temperature 650C and 550C for 12 hours in a furnace. The fused mixture was grounded and mixed with water at 65 g H2O per 100 g SBE. This mixture was aged at 60C and 80C in an oven before crystallization took place in 5 parts by weight 5% KOH for 48 hours. The product obtained was washed 3 times with distilled water using filtration set and dried in oven at 220C for 20 hours. Full multilevel factorial experiments were carried out. Analysis of the results by using Minitab Release 14 Statistical software revealed that the main effect of fusion temperature and aging time was significant. The analysis also showed that there was significant interaction effect of fusion temperature to aging time and aging temperature. The best conditions to synthesize the water adsorbent were: 550°C of fusion temperature, 80°C of aging temperature and 3 days of aging time with water uptake of 0.0353 g H2O / g water adsorbent, approximately to 84% of commercialized of zeolite 3A.

Abstract: In the chemical industry, one of the promising areas is the development of effective technologies for obtaining high-quality mineral fertilizers and feed mineral fertilizers from unconditional phosphate raw materials and improving their technical and economic indicators and agrochemical properties of products. Moreover, the solution to these problems should be carried out on the basis of low-grade raw materials poor in phosphorus content. Such low-grade ores include phosphorites of the Chilisay mine. Phosphorites of this deposit have a number of specific features that create certain difficulties and contain a large number of carbonates, in terms of carbon dioxide reaching 4.56-6.34%, as well as glauconites. When decomposing such phosphorites, large volumes of very stable foam are formed, which complicates the decomposition of phosphorus raw materials and reduces the useful volume of the decomposition chamber by 60-80%, increases the loading time of phosphorite and, accordingly, increases the total time of the process. The objective of the work is to research the process of obtaining high-quality monocalcium phosphate, as well as to determine the optimal decomposition parameters of low-grade phosphate raw materials and to increase the product yield. Based on the conducted research of the Chilisayphosphorite decomposition, monocalcium phosphate was obtained.

Abstract: In this study the kinetics of stibnite dissolution in (Na2S+NaOH) aqueous media has been investigated. The dependence of controlling mechanism and antimony dissolution rate have been studied with respect to Na2S to NaOH ratio, solution temperature, stibnite powder size and solid to liquid ratio. All results (based on f(X)-t curves) have illustrated that the ash layer diffusion could be the rate controlling mechanism of stibnite dissolution via using shrinking core model. Also, XRF and SEM analysis confirms that the ash layer is nonmetallic and could be possibly Silica. In addition to, dissolution reaction was of order 2 and based on the numerical analysis the apparent activation energy of dissolution was obtained as about 18.13 kJ that is acceptably consistent with the results either in f(x)-t diagrams or tables. The accuracy of Shrinking core model has been evaluated through Bischoff criteria and this method has established that the pseudo steady state solution had good accuracy for developing the model. Besides the effect of main leaching parameters (as mentioned above) on antimony recovery has been determined. Results have shown that the leachant concentration ratio (0.75/0.75) has strongly increased the antimony recovery up to 98 percents among other parameters.

Abstract: The huge unconventional resources of natural gas in the earth's crust make it in the future not only the main source of raw materials for global energy, but also the cheapest and most abundant raw material for the production of many basic petrochemical products. However, technological complexity and high energy consumption for multistage processes of converting methane into thermodynamically less stable products remain the main problem constraining development of gas chemistry. A promising solution may be a matrix technology for the autothermal reforming of natural gas into syngas or hydrogen. This technology is based on internal recuperation of heat of conversion products, which is implemented in the surface combustion mode. The review presents the basic principles of matrix reforming, the results achieved so far and the most promising areas of its application.

Abstract: The coffee industry and landfill leachate treatment generate residual waste streams, known as spent coffee grounds (SCG) and landfill leachate membrane concentrate (LLMC). Current practices for managing these residues, including open burning, incineration, and landfilling as a final disposal method, represent a waste of resources and pose a challenge to sustainability. Due to the high pollution potential of solid waste SCG and LLMC, cost-effective management solutions are urgently needed. The present research investigates the slow pyrolysis of SCG using potassium hydroxide (KOH) (weight ratio of 1:1) and LLMC residue (weight ratio of 1:1) as activating agents. The high content of alkali and alkaline earth metals in LLMC could promote the activation of the resulting char and improve the quality of the carbon-based material produced in pyrolysis. The use of LLMC as an activating agent could be a sustainable alternative for valorizing SCG and landfill wastes, potentially replacing ingredients such as steam, CO₂, and chemical additives used on an industrial scale. The SCG had a low specific surface area (4.5 m² g^-1), contrasting with the notable surface areas observed in both activated chars. In particular, the KOH-activated char exhibited a higher surface area than the LLMC-activated char, measuring 1,960 m² g^-1 compared to 1,138 m² g^-1 – a difference of about 72%. On the other hand, the combustion enthalpy of the LLMC-activated material was estimated at 22.04 MJ kg^-1. The combustion enthalpy of LLMC-activated char was about 21.7% and 19.8% higher than that of SCG and KOH-activated chars, which had values of 18.11 and 18.40 MJ kg^-1, respectively. Our findings confirm that pyrolysis of SCG with KOH produces a microporous material with a high specific surface area. In contrast, the resulting LLMC-activated char demonstrates a higher value of combustion enthalpy. This work showed that both activated chars had superior energetic and morphological properties compared to the non-activated char made from SCG biomass. Among the activating agents, KOH led to better performance in terms of char yield and morphological properties. Meanwhile, utilizing LLMC residue as an activating agent highlights its potential for converting landfill waste into high-value material.

Abstract: In this paper we briefly discuss the main points of salinity gradient energy (SGE). First we discuss the sources of SGE and the methods to harvest it. Then we calculate, using the laws of physical chemistry, the amount of energy that can be harvested with three selected methods based on the diffusion of ions, of liquid water and of water vapor respectively. Then we give an overview of the applications, highlighting a number of new developments such as assisted reverse electrodialysis (ARED) and energy storage. It turns out that reverse electrodialysis offers unexpected possibilities such as energy storage, utilizing waste heat and the administration of transdermal drug delivery; a technique that has been launched very recently.

Abstract:

Despite the development of nuclear and alternative energy, thermal power plants operating by burning fossil fuels (coal, petroleum products or natural gas) will retain a significant share in the energy balance for a long time. In this regard, it is of particular interest to reduce CO2 emissions from the combustion of organic fuels through its capture and subsequent use or burial. In our work, mathematical modeling of the two-stage process of membrane extraction of CO2 from the flue gases of a thermal power plant was carried out, taking into account the presence of water vapor and various operating modes of the membrane module. We used commercially available polymer membranes for gas separation in our simulations. The calculations showed: Taking into account the presence of water vapor makes it possible to reduce the required membrane area by 1.6 times; For the degree of CO2 extraction < 80% in one stage, cross-flow and counter-current modes provide equal indicators for the required membrane area, and the co-current mode turns out to be less advantageous already with a degree of CO2 extraction > 60%. In this regard, in the area of low CO2 extraction values at the first stage, any flow organization mode in the membrane module can be selected, and in the high area, a counter-current has a slight advantage over the cross-flow mode; An optimal combination of membrane areas in the first and second stages is shown to achieve the maximum CO2 concentration in the product stream; Polaris Gen-2 membranes provide the best performance after two-stage separation: the CO2 content in the product stream was > 85 mol% and > 90 mol% with a total recovery rate of 80 and 50%, respectively; PolyActive and PPO membranes provide equal indicators for the CO2 content in the product stream, but in the use of PolyActive, the required membrane area is 2.3 times less.

Abstract: The interactions between cellulose nanocrystals and six different polymers (three anionic, two non-ionic, and one cationic) were investigated using rheological measurements of aqueous solutions of nanocrystals and polymer. The experimental viscosity data could be described adequately by a power-law model. The variations of power-law parameters (consistency index and flow behavior index) with concentrations of nanocrystals and polymers were determined for different combinations of nanocrystals and polymers. The interactions between nanocrystals and the following polymers: anionic sodium carboxymethyl cellulose and non-ionic guar gum, were found to be strong in that the consistency index increased substantially with the addition of nanocrystals to polymer solutions. The interaction between nanocrystals and non-ionic polymer polyethylene oxide was moderate. Depending on the concentrations of nanocrystals and polymer, the consistency index both increased and decreased upon the addition of nanocrystals to polymer solution. The interactions between nanocrystals and the following polymers: anionic xanthan gum, anionic polyacrylamide, and cationic quaternary ammonium salt of hydroxyethyl cellulose, were found to be weak. The changes in rheological properties with nanocrystal addition to these polymer solutions were found to be small or negligible.