The ejector is a widely used mechanical device with advantages such as simple structure, low initial cost, easy maintenance, and reliable operation. It is widely applied in fields such as refrigeration, desalination, chemical engineering, fuel cells, aerospace, etc. The ejector does not directly consume mechanical energy, which allows for energy-saving purposes, making it more important and attractive with the national goals of“carbon peaking and carbon neutrality”in China. Machine learning methods, as a data-driven automated analysis approach, can be used for analyzing the internal flow characteristics of ejectors and optimizing ejector performance. In recent years, a small number of scholars have already applied machine learning methods to the study of ejectors in various applications, aiming at improving the ejector performance and the system performance. But the research in the open literature is currently scattered, and the state of the art is not yet clear. The present work comprehensively reviewed the literature on the application of machine learning methods in the study of ejectors for different applications, analyzed the current research status, summarized the machine learning methods utilized in the open literature, and pointed out that in the future machine learning methods can be applied to the study of internal flow characteristics of ejectors, providing a basis and guidance for improving the efficiency and performance of ejectors. Machine learning methods can be applied to the study of ejector performance under variable operating conditions, constructing a pathway from automated design to real-world application of ejectors. Constructing more suitable algorithms and proposing a series of targeted solutions.

The multi-level geometric structures within a fluidized bed influence the dynamics, thermodynamics, and chemical reactions of the internal fluids. Numerical simulation studies of the flow field inside fluidized beds contribute to understanding their complex flow characteristics, establishing a theoretical basis for optimizing the geometric structure and operating conditions of the fluidized beds, thereby enhancing their mass transfer efficiency and performance. Based on computational fluid dynamics theory, a method for the numerical simulation of the flow field within gas-solid fluidized beds was developed. The study investigated the effects of the geometry of the distributor, the diameter of the bed, and the length of the distributor's brim on the flow field within the industrial gas-solid fluidized bed. On this basis, by integrating the Quadrature Method of Moments, a CFD-PBM coupled model was constructed. Utilizing this model, a numerical simulation method for the fluidization state and agglomeration behavior of nanoparticles in the industrial gas-solid fluidized bed was developed, further validating the influence of barrel diameter on the fluidization state of nanoparticles within the fluidized bed. The study indicated that when the diameter was 260mm, the gas velocity distribution around the distributor was uniform, and the dead zone of airflow at the bottom of the distributor was minimized. When the brim length was half the size of the distributor's outlet, the gas velocity distribution within the fluidized bed was more uniform.

The batch distillation process is an important separation and purification process, and its operating condition prediction plays an important role in ensuring the smooth operation of the batch distillation process, optimizing the production quality and yield of batch distillation. This article conducted in-depth research on the model establishment, operating condition prediction algorithm, and simulation software design of the fine chemical D1 batch distillation process. Firstly, a data-driven model for the D1 batch distillation process was established using operation data of historical production, combined with the characteristics of long short term memory (LSTM) and back propagation (BP) neural networks, to predict the rising vapor temperature, distillate temperature, distillation endpoint time, and final product purity. Then, the above work was combined through Matlab's graphical user interface (GUI) to develop a simulation GUI for the D1 batch distillation process, which achieved the prediction of operating parameters and control simulation from data processing to final results. The simulation test results showed that the prediction of batch distillation conditions was fast and accurate, and had important reference value for guiding actual process operations.

In the process of coal pyrolysis, the gas-solid flow and heat transfer behavior in the downer bed with side nozzle play a crucial role in its reaction performance. A heat transfer model considering three heat transfer mechanisms: gas-coal, gas-char convective heat transfer, and coal-char collision heat conduction, was constructed using char as the heat carrier through computational fluid dynamics CFD simulation. A detailed investigation was conducted on the effects of operating parameters such as char density, particle size, and gas velocity on the flow behavior and heat transfer characteristics in a downer bed, in order to provide some qualitative guidance for the promotion and optimization of downer beds. The results indicated that reducing the char density, particle diameter, and gas velocity was beneficial for improving the solids holdup of coal particles. The influence sensitivity to coal heating process from high to low was: char density>gas velocity>particle diameter. In the process of heat transfer, a char density of 900kg/m³, particle diameter of 0.4mm, and gas velocity of 10m/s, were most favorable operating conditions for gas-solid phase convective heat transfer and coal-char collision heat conduction. Among them, gas-char convection heat transfer was dominant, followed by gas-coal convection heat transfer, and collision conduction of coal-char accounts for a relatively small proportion.

According to the characteristics of the methanol to olefins (MTO) process, about 56% (wt) of the reaction products are water, which is an important link in the water balance of the entire plant and the main source of the sewage treatment unit. At present, the water produced by domestic MTO units is discharged to the sewage treatment unit for treatment. If this part of water can be recycled and reused, it can greatly reduce the water consumption per unit product of coal chemical industry. The traditional single separation technology cannot meet the synergistic removal of inorganic catalyst particles and reaction by-products in water. With the increasing demand for environmental protection, multi physics separation technology is increasingly being applied in the wastewater treatment. This work was based on on-site experiments and proposed a microchannel coupled reverse osmosis membrane series treatment process for methanol to olefin wastewater, achieving deep treatment and reuse of the wastewater. Long term experiments showed that the average turbidity of MTO purified water samples after treatment decreased from 24.55NTU to 0.57NTU, and the average COD decreased from the imported 521mg/L to 58.7mg/L. The separation and purification effect was significant. After using a series process to treat the purified water discharged by MTO, a single MTO unit was expected to reduce wastewater emissions by 1.115 million tons per year, save energy consumption of 1.79 × 10⁵kW·h, and save production costs of 17.064 million yuan. This process had the characteristics of low investment, low energy consumption, high treatment efficiency, easy operation, reversible regeneration of adsorption medium and membrane, and stable operation. It effectively solved the problems of difficult reuse and discharge of purified water in methanol to olefin process, and was of great significance for improving water resources and achieving green chemical industry.

The development process of extruder at home and abroad was reviewed, and the important components and process flow of extruder granulation unit were introduced. Through the investigation and technical exchange of the domestic polypropylene extrusion pelletizing unit, as well as the process technology analysis during the test, it was stated that there were shortcomings in the manufacture and design of the extrusion pelletizing unit's pelletizing water driving screen, centrifugal dryer large piece complementor, pelletizing water pipeline, the time of main motor no-load interlocking and three simultaneous sets of values. The cutter pressure and the speed of pelletizing machine, melt index and cylinder temperature were simulated and analyzed. The experience of plant construction, commissioning and operation in the same industry were studied, the pelleting water driving screen was optimized the particle shape observation pipe, the gap between centrifugal dryer large piece complementor and material door was optimized baffle plate, pelleting water pipeline was optimized the branch pipeline for breaking vacuum, main motor no-load interlock was optimized no-load interlock trigger time. The delay time of receiving the cutting through valve in “three simultaneous” was optimized. The cutter pressure and pelletizing machine speed, melt index and barrel temperature were fitted by software, the fitted data were applied to the actual operation of the extruder. Through the above process optimizations, the domestic large extrusion granulation unit realized long-term safe and stable operation, the polypropylene pellet shape was very good. The results showed that the implementation of the above processes optimization solved the problems in manufacturing, installation and operation of Huating extruder, and promoted the development of domestic extrusion granulation unit technology.

Hydrogen is a reliable clean energy, and the hydrogen doping of natural gas with a volume concentration of 10%—20% is currently a hot spot in the research on the economical and efficient transportation of hydrogen at home and abroad. However, the density, calorific value, resistance, etc. of natural gas change after hydrogen doping, breaking the dynamic balance of the pipeline network. Different hydrogen doping ratios have an impact on the compatibility, safety accidents and integrity of pipelines, which will increase the risk of pipeline failure. Therefore, this paper analyzed the failure risk of the dynamic process of hydrogen doping in natural gas pipelines, identified various risk factors that might occur in the process of hydrogen doping, established an ^{accident tree with the failure of natural gas hydrogen doping pipelines as the top event, and then transformed it into the corresponding Bayesian network according to the mapping relationship between the accident tree and the Bayesian network. The time factor was incorporated into the analysis, and the dynamic Bayesian network analysis of natural gas hydrogen doped pipeline failure was carried out to obtain the key factors leading to pipeline failure and the change trend over time. Considering that different hydrogen doping ratios would have an impact on the prior probability of some basic events of pipelines, the failure probability was updated under the condition of 5%—30% hydrogen doping ratio, and the change trend of pipeline failure probability with hydrogen doping ratio was obtained, which provided new ideas and methods for the risk management and control of natural gas pipeline hydrogen doping technology.}

Accurate prediction of reconstructed molecular fractions provides foundational data for constructing reaction kinetics models and simulating actual refining processes. And this contributes to enhance raw material utilization and product quality. Available molecular reconstruction models have paid more attention to the simulation accuracy of bulk properties rather than molecular composition. The reconstructed molecular library was moderately complex and well-organized by superposing core structures and homologous sequences. The molecular structural distribution patterns were studied. Constrains on molecular compositions were added and the molecular reconstruction model of oil composition based on molecular structural distribution was proposed. Vacuum gas oil molecular library was reconstructed with the reference of models that only focused on bulk properties. The reconstructed molecular structures and fractions were closer to actual oil, and the relative error of bulk properties was 1.08%.The results showed that the constrains of molecular structural distribution patterns could improve the simulation accuracy of molecular composition with little bulk properties error.

Biogas is a kind of gas transformed by biomass fermentation. At present, the biogas burners are mainly diffused burners and atmospheric burners, which generally have low thermal strength and are easy to blow out. Based on fully premixed water-cooled combustion technology, a kind of water-cooled biogas burner was designed. Then, the effects of CO₂ content, excess air coefficient, heat load and cooling water temperature in simulated biogas on combustion characteristics of burners were explored. The results showed that the designed burner had good adaptability for biogas with methane concentration from 55%—80%. As the CO₂ content increased, the combustion temperature decreased, the NO _x and CO content at the outlet decreased, but the flame length increased. As the excess air coefficient decreased, the combustion heat intensity improved, however, the NO _x and CO content in the flue gas increased. The result showed that the heat load of burner had a great influence on the maximum combustion temperature. The burner could still operate stably under the minimum load of 35%.

Heat exchangers, as vital energy conversion devices in chemical engineering, face significant challenges due to flow-induced vibrations (FIV) of tube bundles, which are a crucial factor in inducing vibration fractures. The safety and reliability of these systems become particularly critical. In engineering calculations of the vibrational response caused by FIV, it is necessary first to determine the power spectral density (PSD) of the fluid excitation forces, which requires extensive testing data of the fluid excitation forces. This paper designed a special structure heat exchanger tube and conducted experiments in a two-phase flow water tunnel using an electronic pressure scanning valve, validated by reliable accelerometer testing methods. The results demonstrated that the testing method proposed in this paper could accurately measure the fluid pressure exerted on the tube bundles under two-phase flow conditions without affecting the surrounding flow field. At lower gas content, vortex shedding occurred, and both lift and drag increased with rising gas content. An increase in gas content disrupted vortex formation, exacerbating vibration damage during turbulent flutter of the tube bundles. The dimensionless reference equivalent power spectral densities obtained using two conversion methods were highly consistent. The experimentally obtained PSDs were compared with the dimensionless reference equivalent PSDs determined by other researchers, showing overlapping data sets and similar overall trends, thus validating the rationality of the testing method described in this paper. This testing method could provide foundational data support for the design, operation, maintenance, structural improvement, and safety assessment of steam generators.

Medium-temperature heat pipes have potential applications in the fields of secondary heat exchange in nuclear reactors, medium-temperature constant temperature control and thermal protection of aircraft, etc. It is of great significance to carry out the study of precious metal heat pipes using numerical simulation and optimize their full-parameter design. First, a porous reflux model was added to the adaptive phase change model by UDF, and the accuracy of the model was verified by comparing the experimental data and the conclusion of the base model. Secondly, the orthogonal test method was introduced to study the order of importance of the influence of each factor on the performance of the heat pipe under the interaction of all factors, and the result proved that the order of significance of the influence of the factors within the range of the selected working conditions was inclination angle>aspect ratio>liquid filling ratio>mesh number, and the optimal design conditions were 17.18 aspect ratio, 15% liquid filling ratio, inclination angle δ=45°, and 50-mesh screens. And under this condition, the overall thermal resistance was only 15.6% of the worse working conditions, and the heat transfer performance was significantly enhanced. Finally, by comparing and analyzing the phase distribution, temperature distribution and dry burning phenomenon inside the heat pipe and porous structure from the beginning of the complete startup to the quasi-steady state process, it was proved that the distribution of condensate inside the porous structure of the heat pipe wall under the optimal design parameters could be maintained uniformly and continuously, which effectively avoided local overheating of the wall and significantly improved the temperature uniformity of the heat pipe. At the same time, the matching of the parameters such as length-to-diameter ratio and liquid filling rate made the effective heat transfer length of heat pipe up to 100%.

Particulate matter, a by-product of the municipal solid waste incineration (MSWI) process, can cause air pollution and contribute to haze formation. Exploring the formation mechanism of particulate matter in incinerators and the influencing factors from the generation source is very important for pollution reduction. In this article, the modeling and analysis of particle concentration in incinerator under benchmark conditions based on coupled numerical simulation was proposed. Firstly, the process flow for particulate matter generation was analyzed to determine the main factors affecting the concentration of particulate matter. Then, a numerical simulation model of particulate matter in incinerator coupled with fluid dynamic incinerator code (FLIC) and Fluent software was constructed for the real benchmark conditions. Then, the influence of the above main factors on the concentration of particulate matter was analyzed by single factor method. Finally, the optimal parameter combination of multiple factors (particle injecting velocityis 0.15m/s, 60μm, wall-jet) was obtained based on orthogonal experiment and range analysis. The effectiveness of the proposed method was verified by the actual data provided by an MSWI plant in Beijing. The results indicated that when the particle size was between 35—55μm, the concentration of particulate matter gradually increased with the increase of particle size, which can provide data support for reducing the concentration of particulate matter from the perspective of process improvement and optimal control.

Under dry friction conditions, the mechanical seals of kettle equipment experience poor heat dissipation and lubrication, leading to significant thermal deformation and wear problems on their seal faces. Strengthening the seal end face by deposition of diamond-like carbon, DLC coating can effectively decrease the coefficient of friction and prevent thermal deformation, thereby extending the seal's lifespan. Based on the seal structure of the reactor and considering the basic material of the seal ring and the characteristics of DLC, friction coefficients and wear rates of the frictional pairs formed by different thicknesses of DLC coatings and resin-impregnated graphite were tested by using a friction and wear testing machine under various working conditions. The friction coefficients obtained from the experiments were utilized to establish a thermal-structural integrated model of mechanical seals using finite element software. The temperature field and deformation field of the end face with typical DLC coating thicknesses were analyzed in conjunction with the experimental results. The wear reduction effect of DLC coating was also analyzed based on the experimental results. The analysis results indicated that the DLC coating had a significant wear reduction effect compared with the friction pair without DLC coating. At different pcv values, the DLC coating could decrease the friction coefficient by 43.9%, the wear rate by 67.53%, and the steady-state temperature and deformation by approximately 18% and 25% on average, respectively. The frictional pair formed by the 6μm DLC coating had a better performance than that formed by the 2μm coating, with the peak temperature and deformation were further reduced by 2.23% and 2.52% at the maximum. The DLC coating could reduce the wear rate of the end face, steady-state temperature and deformation, offering reference for prolonging the life of reactor mechanical seals under dry friction conditions and enhancing seal stability.

Global warming is becoming increasingly serious, new environmentally friendly refrigerant research is imminent. The refrigeration industry also needs to replace existing refrigerants and further enhance the heat transfer efficiency of heat exchangers. Experimental research on the flow boiling heat transfer of R513A in different structures of tubes was conducted to explore the mechanism of different enhanced structures, mass flow rates [300—500kg/(m²·s)], and evaporating temperatures (5—10℃) on the heat transfer coefficient and pressure drop. The results showed that the heat transfer coefficient of R513A in microfin tubes was 23%—120% higher than that in smooth tube, while the pressure drop was higher than that in smooth tube. Larger helix angles exacerbated the generation of secondary flow in the tube; a larger number of teeth can increase the effective heat transfer area of boiling heat transfer, enhancing heat transfer. The boiling heat transfer coefficient and pressure drop of R513A increased with increasing mass flow rate; as the evaporating temperature rose, the heat transfer coefficient increased while the pressure drop decreased. By comparing the unit pressure drop heat transfer coefficient, it can be concluded that the 4# microfin tube had the best heat transfer performance. The differences in thread parameters mainly affected the comprehensive performance of microfin tubes in the low and medium vapor quality, with less impact in the high vapor quality. Under the present experimental conditions, the Kaew-on correlation and Chisholm correlation had the highest accuracy in predicting the heat transfer coefficient and pressure drop inside the smooth tube for R513A, with a mean relative error of -4.74% and 7%, respectively; and the Yu correlation and Miller-Steinhagen correlation were better in predicting the heat transfer coefficient and pressure drop inside the microfin tube, with a mean relative error of 14.16% and 3.66%, respectively.

In response to the current demand for miniaturized and high-performance heat dissipation in electronic devices, the study of fluid flow heat transfer within nanochannels has garnered significant attention. In this paper, the molecular dynamics simulation method was used to investigate the heat transfer characteristics of water molecules flowing through asymmetric channels under varying heat source temperatures. The results indicated that the fluid flow and heat transfer process were affected by the increase of the groove structure in the bottom part and the change of the heat source temperature. The increase of groove structure enhanced the gathering ability of water molecules at the structure, while higher heat source temperature dispersed the high-density region formed. However, increasing the groove structure weakened the overall flow velocity in the channel, reduced the velocity slip at the bottom wall surface, and increased the flow resistance coefficient. Conversely, increasing the heat source temperature had the opposite effect, improving the process of the water molecule flow. Under the same heat source temperature, the temperature of water molecules near the bottom rough wall surface was higher than that near the top wall surface. Increasing the groove structure will increase the heat transfer area between the solid-liquid, reduce the temperature jump length of the solid-liquid interface, and increase the Nusselt number. However, increasing the temperature of the heat source will enhance the temperature jump length of the interface, weaken the heat transfer between the solid-liquid, widen the temperature difference between the fluid and the heating wall, and decrease the Nusselt number.

Micromixing technology has a broad application prospect in the fields of microchemistry, biomedicine, and new energy due to its features of small sample size, low consumption, high mixing efficiency, and ease of integration. The micro-mixer design used in current research usually fails to take into account the design complexity and mixing efficiency, and lacks the related mechanism research based on the application-oriented. The use of numerical simulation can refine the mixing process and help to mechanistically analyze the results. In this work, a mutualistic-rotational inwardly oriented composite phyllotaxy microchannel model was developed. Through the simulation results of the flow velocity field, pressure field and particle distribution in the microchannel, the diversion and obstruction effects of the structural elements were analyzed, and the influences of their angle, spacing and circulation density on the fluid flow pattern and mixing effect in the microchannel were discussed. The results showed that the fluid velocity vector played a key role in the flow pattern and mutual diffusion of different fluids, and was the decisive criterion of mixing effect. Among them, the component angle mainly affected the directional difference of the fluid velocity vector, the component spacing determines the degree of fluid-field coupling in neighboring regions of action, and the component circulating density mainly affected the change magnitude in the direction of the fluid velocity vector, it was finally concluded that the mixing effect was able to reach 98% when the angle was 45°, the spacing was 2mm, and the circulation density was 4.

Based on the epoxidation of fatty acid methyl ester catalyzed by peroxyformic acid, a novel liquid-liquid impinging stream cyclone reactor was proposed. The cold mixing performance of fatty acid methyl ester and peroxyformic acid in the reactor was investigated using the Eulerian-Eulerian model and RSM turbulence model. Besides, the dispersion uniformity of the dispersed phase was used to quantify the mixing performance in the liquid-liquid impinging stream cyclone reactor. Moreover, the effects of the two-phase inlet angle, inlet rising angle and relative position of inlet on mixing efficiency were studied. The results showed that the two-phase liquid in the impinging stream contact cavity was gradually mixed evenly under the action of impinging stream. Characterized by dispersion uniformity, when the two-phase inlet angle was 60°, the inlet rising angle was 10° and the relative position of the inlet was 5mm, the mixing effect of the reactor was the best.

Gas is an efficient, stable, and low-carbon clean energy. In the context of achieving carbon peak and carbon neutrality goals, vigorously promoting the development of urban gas can effectively improve energy utilization efficiency. It is not only an effective path to meet the high-quality energy demand of cities, but also an important measure to promote energy conservation and carbon reduction, and achieve green and low-carbon transformation in cities. Due to the characteristics of flammable, explosive, and easily diffusible nature of gas, with the rapid development of urban gas, gas safety issues have become increasingly prominent, and related accidents have occurred from time to time. In order to effectively prevent and resolve gas safety risks and hidden dangers, resolutely curb the occurrence of major accidents, and better promote the high-quality development of the gas industry, this article adhered to the five guiding principles of goal, systematicity, feasibility, scientificity, and localization. For the first time, the methodology of resilience assessment was combined with gas safety assessment. The Analytic Hierarchy Process was applied to establish a quantitative evaluation system for urban gas safety resilience, which sorted out, formulated, and evaluated indicators related to urban gas safety, providing strong support for promoting the intrinsic safety of urban gas.

With the rapid development of renewable energy technologies, ammonia synthesis with hydrogen produced via water electrolysis have received increasing attention. Since 1920s, this process has evolved from hydroelectric powered to the current wind/solar powered in over a century. This article comprehensively reviewed the history of ammonia industry, introduced the technological evolution and characteristics of diverse ammonia synthesis routes, e.g. via fossil energy, wind/solar power and grid electricity produced hydrogen. In addition, the current technical situation of ammonia synthesis with hydrogen produced via water electrolysis in China was deeply analyzed, and the future industrial scale of this route was also predicted. It was expected that the output value of the domestic synthetic ammonia industry would reach 317.3 billion CNY by 2030 and 790 billion CNY by 2050. Thoughts on the development of the domestic synthetic ammonia industry were proposed and two viable paths were outlined. Firstly, in regions with abundant and cheap renewable electricity, ammonia can serve as an effective means of power storage and consumption; Secondly, the green transformation of existing ammonia synthesis plants can be achieved by partially substituting fossil feedstocks with green hydrogen, thereby gradually unleashing and expanding the production capacity and environmental benefits of ammonia synthesis.

Liquid organic hydrogen carrier (LOHC) technology is a promising liquid hydrogen storage technology, but slow kinetics during LOHC dehydrogenation process has restricted the development of LOHC. The reactor design based on heat transfer, mass transfer and kinetics enhancement is an inevitable choice. This paper analyzed the mechanism of LOHC dehydrogenation kinetics enhancement, and pointed out that high concentration of reactants and high temperature on the catalyst surface were the key to high reaction rate, and the byproducts and catalyst deactivation should be reduced. It proposed heat transfer and mass transfer enhancement strategies and introduced the objectives and measures of heat transfer enhancement of fixed bed reactor as an example. It pointed out that mass transfer enhancement should increase the external diffusion rate and avoid the influence of internal diffusion. The research summarized progress and intensification strategies of various types of LOHC“gas-liquid-solid”three-phase reactors. Finally, it summarized the characteristics of these reactors and put forward the possible new reactor design direction. It could provide theoretical ideas and reference for developing new reactors for LOHC dehydrogenation process.

The application of metal-rare earth doped ceria anode is one of the most important strategies for the moderate and low temperature solid oxide fuel cells (SOFC). The mixed ionic and electronic conductor (MIEC) characteristic of doped ceria expands the reaction interface and complicates the reaction mechanism. This article reviewed the electrochemical oxidation mechanism of H₂ and CO in metal and doped ceria system. It was pointed out that the Ni/YSZ-like H spillover mechanism was dominant in the H₂ electrochemistry. For the CO electrochemistry, combined with the predominant Marse-van Krevelen (MvK) type mechanism in the CO catalytic reaction and the reverse process of the CO₂ electrochemical reduction reaction, it was predicted that the charge transfer step mainly occurred in the oxygen vacancy formation and the CO₂ formation reactions. In the MIEC type reaction mechanism, the main difference in the H₂ oxidation reaction pathways was the difference of H₂ dissociation adsorption site. The CO oxidation reaction pathway can be categorized into two modes based on the adsorption site: directly reacting with CeO₂ lattice oxygen to generate CO₂ or generating carbonate intermediates, and the charge transfer step involved carbonate formation and CO₂ formation reactions. In summary, H₂ electrochemical oxidation was dominated by H spillover, while the dominant reaction mechanism of CO electrochemical oxidation was still unclear and required further study. This article was instructive for clarifying the reaction mechanisms of Ni/YSZ and MIEC types in H₂ and CO, as well as H₂/CO hybrid fuel systems.

Alkyl-based bio-liquid fuels play an important role in biomass applications. The first generation of biodiesel (fatty acid methyl ester) has high oxygen content, low calorific value, and limited mixing ratio with fossil fuels, so the second generation of hydrocarbon-based biodiesel,which is mainly prepared by thermal catalytic hydrogenation and deoxygenation isomerization process, has attracted much attention, and the study of catalysts is crucial. The composition of catalysts mainly includes metal active components and carriers. Due to the high cost of precious metal catalysts, they are not easily applied on a large scale in industrial production. Therefore, in the production and research of second-generation hydrocarbon-based biodiesel, emphasis is placed on developing non-precious metal catalysts with high conversion rates, high selectivity, good stability, and low cost. This paper expounds on the catalytic hydrogenation and deoxygenation process, focusing on the catalytic activity, catalytic conversion mechanism, catalyst deactivation reasons, and other catalytic characteristics of non-precious metal (Ni, Mo, W, Co, etc.) catalysts in the preparation of hydrocarbon fuels from biomass. At the same time, prospects for future research on non-precious metal catalysts in oil and fat hydrogenation and deoxygenation catalysis are proposed.

The phase-change heat storage and energy storage system was designed, and the regular hexagonal brick and composite phase change materials (CPCM) were innovatively adopted. The characteristics of the heat storage and release process of the phase-change heat storage and energy storage system were numerically simulated by ANSYS Fluent, and the heat storage and release process was studied. The influence of the shape, material and heating power of the phase-change thermal storage brick on the heat storage process of the designed phase-change thermal storage system, as well as the influence of CPCM thermal storage temperature, air inlet flow rate and air inlet temperature on the heat release process were investigated. The simulation results showed that under the heating power of each heating rod of 0.7kW, the charging time required for the heat storage process was about 7.7h, and the average temperature of the heat storage body could reach 870℃. The simulation results met the design requirements. The regular hexagonal brick showed better heating uniformity, the heat accumulator with CPCM had better heat storage performance, and the increase of heating power could greatly accelerate the heat storage process. In the heat release process, 1m/s air inlet flow rate was more appropriate, and the required discharge time was 14.6h. The faster the air inlet flow rate, the lower the temperature and the lower the CPCM heat storage temperature, the higher the heat release rate of the system. The total heat storage and release time of the system was about 22.3h, which could realize the utilization of peak and valley electricity well.

At the early stage of oilfield development, the water content of wellhead extractive fluid is low, and the tubing flow is very easy to form water-in-oil(W/O) emulsion in the process of gathering and transporting. When the temperature of oil gathering is lowered, the wax molecules are precipitated, and a large amount of condensate adheres and accumulates on the inner wall of the tubing, resulting in the increase of back pressure at the wellhead. And in serious case, accidents such as plugging of the tubing may occur, which are a great obstacle to the cooling down and transporting. Therefore, it is of great significance to study the lower limit of unheated oil gathering temperature for waxy crude oil in the low water content stage and put forward the method of determining the boundary condition of unheated gathering temperature for the unheated gathering process in the early stage of oilfield development. The indoor pressure simulation tank device was used to carry out wall-sticking experiment of waxy crude oil in the low water content stage, wall-sticking law of waxy crude oil in the low water content stage was analyzed, and it was determined that the freezing point, water content, and shear rate was the main factors affecting the sticking wall temperature. An wall-sticking temperature prediction model for waxy crude oil in the low water content stage unheated gathering and transportation was established, which was verified by the oilfield field ring road test device, and the error was within 2℃, which met the requirements of engineering application.

The gas pressure environment of in situ pyrolysis of tar-rich coal under different pressures was simulated by means of pressure reaction apparatus and molecular dynamics. In the laboratory, tar-rich coal with particle size of 1mm was selected as raw material, pressurized thermogravimeter and high pressurized reactor were used to simulate the in situ pyrolysis of tar-rich coal, and the pyrolysis activation energy of tar-rich coal under different pressures was calculated by sectioning method. ReaxFF numerical simulation was used to analyze the pyrolysis process of tar-rich coal molecules under different pressures. The relationships among different pressure, temperature, tar yield and tar composition characteristics were discussed. It is found that the change of pyrolysis pressure has a limited effect on the pyrolysis activation energy, but has a significant effect on the product characteristics. The activation energy of tar-rich coal pyrolysis to form semi-coke is slightly lower with the increase of pyrolysis pressure at first stage of pyrolysis, and at second stage of pyrolysis the activation energy modestly increases with the increase of pressure. The maximum oil yield is 9.54% at 600℃ under simulated in situ pyrolysis conditions of tar-rich coal. At 2MPa, the maximum oil yield decreases to 5.42% with the increase of pressure, and the content of PAHs in tar increases with the increase of pressure. Through molecular dynamics simulation of tar-rich coal under different temperature and pressure, the pyrolysis trend similar to the experiment is obtained. In the molecular dynamics simulation, the total amount of tar increases with the increase of temperature within 2000K, and the tar production at each temperature point shows a downward trend with the increase of pressure. The tar production reaches a maximum of 23.67% at 2000K and 3MPa, corresponding to the maximum tar output at 600℃ and atmospheric pressure under experimental conditions. ReaxFF numerical simulation results show that higher temperature leads more obvious influence of pressure. At 2300K, the amount of gas produced is inversely proportional to the pressure, and the amount of tar begins to decline compared with that at 2000K. In this study, experiments related to pyrolysis of tar-rich coal under pressure were completed, and the results of pyrolysis of tar-rich coal under pressure were supported by molecular dynamics simulation, which can provide data support for the research on in situ pyrolysis of tar-rich coal.

Regenerator is widely used in gas waste heat recovery and its structure determines the efficiency of waste heat recovery. Therefore, the aim of this study was to propose an improved design scheme of multi-layer plate regenerator by comparing the numerical simulation analysis, and systematically discuss its structural optimization and performance characteristics. The heat transfer process of regenerator was simulated by the method of fluid-solid-heat coupling. The different opening forms (such as through hole, double hole and double half hole), the influence on gas flow, temperature distribution and pressure distribution in regenerator were mainly analyzed. The results showed that reasonable increase of the opening could not only improve the uniformity of the internal temperature of the regenerator, but also enhance the overall thermal performance. The design of double-hole structure had prominent advantages in reducing pressure loss, improving heat storage efficiency and enhancing heat transfer capability. In addition, this paper also provided an efficient and feasible technical path for the optimal design of the new-type regenerator structure.

Homogeneous catalysts suffer from difficult separation and regeneration, which seriously limits its application in industry. To solve these problems, supported Pt heterogeneous catalyst has been prepared by impregnation, co-precipitation and ion exchange. Introducing disparate heterogeneous catalyst supports can change the coordination environment of Pt particles, and thus presents an effective approach to improve the selectivity. Here in the review, the preparations and applications in oxidation, hydrogenation and hydrosilylation of the heterogeneous platinum catalyst supported by inorganic materials (zeolite molecular sieve, carbon nanomaterials, silica and metal oxide) and polymers have been summarized, and the advantages and disadvantages of different supports have been analyzed. The results indicate that the prospective development trends of improving the activity, selectivity and stability of Pt-based heterogeneous catalysts are adjusting preparing process, changing the size and spatial structure of the support, and introducing composite or multiple active centers into support.

Support is one of the important components of supported catalyst, playing a crucial role in maintaining the stability and performance of catalyst. This paper systematically introduces the research progress of carbon materials used in hydrodesulfurization catalysts, focusing on two aspects: pure carbon-based support catalysts and carbon-inorganic oxide composite support catalysts. The types, properties and applications of carbon-based support were summarized, and the promoting effects of different carbon-based support on the active phase and catalytic activity were elaborated. Finally, based on the current research status of carbon-based support hydrodesulfurization catalysts, the future research direction of carbon-based support is prospected. On one hand, it can focus on the design and development of new carbon-based supports. It is important to diversify the types of carbon-based supports that can be used to prepare composite supports, and fully take the morphological and structural advantages of carbon materials. On the other hand, it is necessary to thoroughly investigate the effects of pore structure and morphology of carbon-based supports on the active components and catalytic performance of catalysts, and clarify the hydrodesulfurization mechanism of the catalysts with different types of carbon-based supports.

Biomass is a potential alternative resource for fossil fuels, and lignin is the second largest abundant reserves of biomass resource in nature. The catalytic conversion of lignin into high value-added chemicals is of great significance for the implementation of the national dual carbon strategy. Catalysts and solvents are key factors affecting the catalytic conversion of lignin. This article outlines the mechanisms and performance control laws of commonly used metals, molecular sieves, and metal oxide catalysts in the process of catalytic hydrogenation of lignin. Different solvent dispersion and hydrogen supply are compared and analyzed. Through in-situ characterization of solvent effects and simulation of solvent reaction pathways, the structure-activity relationship between catalyst structure and performance is explored, clarifying the synergistic mechanism of catalysts and solvents on lignin catalytic hydrogenation, providing a theoretical basis for the resource utilization and high-value utilization of lignin.

The direct epoxidation of 3-chloropropene for synthesizing epichlorohydrin is a green chemical process, but highly relies on efficient epoxidation catalysts. The currently developed catalysts for epoxidation are predominantly homogeneous catalysts, such as phosphotungstate and metal complexes, and heterogeneous catalysts typified by titanium silicate molecular sieves. Among those homogeneous catalysts, phosphotungstate demonstrate superior reactivity due to their phase-transfer characteristics. This paper offers an overview on the synthesis of phosphotungstate catalysts and their current application in epoxidation processes. Regarding heterogeneous catalysts, the paper summarizes the reaction mechanism and progress in catalyst modification of titanium silicate molecular sieves for the epoxidation of 3-chloropropene. The application status of this catalyst in the epoxidation process is analyzed, and recommendations are given for further catalyst research in an industrial context. Additionally, a direct epoxidation scheme for 3-chloropropene employing molecular oxygen as the oxidant is discussed. Dual-functional catalysts suitable for this reaction should be developed to reduce the production costs of the direct epoxidation process for 3-chloropropene.

Photocatalytic conversion of carbon dioxide (CO₂) into value-added chemicals and fuels is one of the promising strategies for mitigating global warming and achieving the goal of carbon neutrality. In order to promote the development of this field, the design and synthesis of efficient photocatalysts is critical. Compared with previous studies, low-concentration CO₂ photoreduction received intensive research in the past five years. Hence, this review explores the latest advancements in structure design of photocatalyst for diluted CO₂ reduction. Firstly, the mechanism and pathways of CO₂ photoreduction as well as their influencing factors are briefly introduced. Secondly, the structural characteristics and regulation strategies are reviewed in term of four types of photocatalyst, including metal-organic framework, covalent organic framework, metal oxides, and single atom photocatalysts. The effects of CO₂ adsorption and enrichment, electron-hole separation and migration and surface site activity on the efficiency and selectivity were deeply investigated. Finally, in response to the opportunities and challenges of photocatalyst for efficient diluted CO₂ reduction, including product selectivity, conversion efficiency and the synthesis of high-value C₂ products, we proposed relevant solutions and strategies regarding catalyst structure design.

Compared with petrochemical diesel, green diesel produced by oil hydrodeoxidation has advantages of biodegradability, environmental protection and low toxicity. In the research of green diesel, the development of catalyst is very important. In this paper, the mechanism of oil hydrodeoxidation to green diesel oil, various hydrodeoxidation catalysts, catalyst deactivation and regeneration are introduced. Noble metal reserves are scarce, so the price is high, which limits their industrial applications. The hydrogenation of metal sulfide catalyst may lead to sulfur leaching, which deactivates the catalyst and leads to product contamination. Reduced non-noble metal, metal carbide, nitride and phosphide catalysts are widely concerned because of their high cost-effectiveness and pollution-free, but the preparation process is complicated and the catalyst life is short. Therefore, the use of additive modification and different carriers for non-noble metal catalyst, and the development of cheap, efficient, environmentally friendly catalyst are the future development directions.

A series of Ca-ZSM-5 catalysts with different loading amounts were prepared by ion exchange method. The catalytic performance of the catalysts for the preparation of cyanamide from urea dehydration was investigated in a fixed bed reactor. X-ray diffraction (XRD), N₂ physical adsorption, scanning electron microscopy (SEM), ammonia temperature desorption (NH₃-TPD) and pyridine infrared (Py-IR) were used to analyze the changes in the physical structure, microstructure and acidity of the catalysts before and after modification. The results showed that the physical structure of the modified catalyst was basically unchanged, but the specific surface area decreased with the increase of calcium load. After modification, the strength of weak acid and medium strong acid sites did not change significantly, but the strength of strong acid sites diminished, and the acid content of weak acid and medium strong acid increased significantly. In addition, the proportion of L-acid in the catalyst increased significantly, while the amount of B-acid decreased slightly, and thus the value of B/L decreased. When the reaction temperature was 550℃, urea feed rate was 0.2g/min, NH₃ velocity was 3000h^-1, condensate temperature was 0℃, and “0.1Ca-ZSM-5” was used for a 30 min reaction, the urea conversion was 91.1%, the selectivity and yield of cyanamide were 40.5% and 36.9%, respectively.

HY molecular sieves were dealuminized with nitric acid of different concentrations. The dealuminized HY molecular sieves had different specific surface areas and pore sizes. The Sn-doped bifunctional catalyst for the conversion of glucose to 5-HMF was prepared by impregnation method using the dealuminized molecular sieve as the carrier. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N₂ adsorption/desorption, X-ray photoelectron spectroscopy (XPS) and acid-base titration. The results showed that the synthesized 0.5mol/L-10% Sn-HY had mesoporous structure, octahedral morphology and suitable B/L acid site ratio. In the reaction system of methyl isobutyl ketone (MIBK) and NaCl-H₂O, the yield of 5-hydroxymethylfurfural was 67.3% under the optimized conditions of 0.2g catalyst, 165℃ and 60min. After five cycles, the 5-HMF yield could still reach 49%, indicating that the catalyst had good stability. Meanwhile, the reaction mechanism for the conversion of glucose to 5-HMF was preliminarily investigated. Overall, this work established an efficient multiphase catalytic system that demonstrated the great potential of converting biomass into platform compounds.

A series of Ru-K-NaY catalysts with different Ru contents were prepared by using the method of excess impregnation which used NaY molecular sieves as carriers and pretreated by KNO₃ solution. The catalysts were used for the first time in the reaction of decarbonylation of dimethyl oxalate(DMO) to prepare dimethyl carbonate(DMC). The effects of Ru loading and catalyst base on the reaction were investigated. The surface and structural properties as well as the alkaline properties of the Ru-K-NaY catalysts were characterized using XPS, BET and CO₂-TPD, and it was determined that increasing the number of weak alkaline active sites as well as the number of Ru⁰ species of the catalysts could improve their catalytic activity and promote the generation of dimethyl carbonate. The reaction using Ru-K-NaY catalyst was optimized, yielding the DMO conversion and DMC selectivity were 83% and 69%, respectively. Finally, the stability test showed that the catalytic activity of the Ru-K-NaY catalyst was almost unchanged after 5 cycles.

Polymerized small molecular acceptors (PSMAs) have received increasing attention as they preserve the merits of fused ring small molecule acceptors (SMAs) and the good film-forming properties and light-irradiation stability of polymers. However, most of the PSMAs are regiorandom at present, which would not only negatively affect the batch-to-batch reproducibility of PSMAs, but also would disturbs the molecular configuration and electronic structure, and affect the intermolecular π-stacking, resulting in a significant decrease in its mobility. In recent years, researchers have designed and synthesized many regioregular PSMAs through strategies such as core engineering, terminal group engineering, linkage unit modulation and side chain engineering, and the power conversion efficiencies (PCEs) have been significantly improved. In this paper, the research progresses of regioregular PSMAs in high-performance all-polymer solar cells (all-PSCs) in recent years were reviewed. It was believed that in the future, higher PCE can be achieved through synthesis of new PSMAs with reasonable molecular structure design by strategies of core engineering, terminal group engineering, linkage unit modulation and side chain engineering together with appropriate donor materials and device process optimization.

The ZIF-8 membrane represents a novel class of metal-organic framework (MOF) materials characterized by nanoporous structure. Due to its distinctive honeycomb-like porous structure and remarkable thermal and chemical stability, ZIF-8 membranes have gained significant traction in the field of gas separation in recent years. The pore size of ZIF-8 membranes lies between the kinetic diameters of hydrogen and other gases (e.g., N₂, CH₄, etc.), rendering them particularly suited for the separation of hydrogen. This paper reviewed the preparation methods of continuous ZIF-8 membranes with a focus on the in-situ growth method, the secondary crystal seeding method, the surface modification method and some special preparation methods that were represented in the last decade. This review presented a comparative analysis of the hydrogen separation performance of continuous ZIF-8 membranes prepared by the aforementioned methods along with an evaluation of the advantages and disadvantages associated with each method. In parallel, the synthesis mechanisms of the in-situ growth method, the secondary crystal seeding method and the surface modification method were presented in detail. Furthermore, prospective avenues for future research and the associated challenges are briefly outlined.

Asphalt pavement will produce high-temperature rutting, low-temperature cracking and other diseases in the extreme temperature environment, and the development of composite phase change materials is of great significance to improve the temperature regulation performance of asphalt, to further advance the development of thermoregulation technology for asphalt pavements and to improve the life cycle of phase change materials in asphalt. First, the composition of composite phase change materials for road use was introduced. Second, the preparation process of composite phase change materials was compared. On this basis, the discussion was mainly based on the temperature-regulating performance of asphalt pavement and the influence caused by the blending of composite phase change materials on asphalt pavement. It was sorted out that the carrier was a key factor in determining the thermal conductivity and durability of composite phase change materials. Therefore, after determining the composite phase change materials carrier, it was crucial to choose the appropriate preparation method for different carrier materials. The use of carbon-based materials with high thermal conductivity in the carrier can not only improve the leakage resistance of composite phase change materials, but also improve the thermal conductivity of composite phase change materials. At present, although composite phase change materials had certain temperature regulation performance in asphalt, they still had the shortcomings of low heat storage capacity and insufficient leakage resistance. In the future, on the basis of clarifying the compatibility of composite phase change materials with asphalt, more targeted composite phase change materials for road use can be developed, and then a unified phase transformation evaluation standard and method can be formulated.

Zeolitic imidazolate frameworks (ZIFs) are considered to be one of the best materials for breaking through the upper limit of membrane materials due to their structure being adjustable, easy preparation and excellent stability. In this study, a high-performance dye desalination mixed matrix loose nanofiltration membrane was obtained by the in-situ growth of ZIF-L particles on a polyethyleneimine (PEI) based coating and followed by interfacial polymerization with trimesoyl chloride (TMC). Using the coordination action between PEI and Zn²⁺, the uniform distribution of Zn(Ⅱ) ions was ensured and also established an in-situ generation of ZIF-L nanoparticles with the polyamide interface, avoiding the formation of interface defects. The in-situ generation of ZIF-L particles increased the roughness of the membrane surface and improved the surface hydrophilicity, providing a water channel for the separation layer and shortening the water transport path. For the Congo red/salt mixed solution, compared with the PEI/TMC membrane without ZIF particle loading, the PEI(ZIF)/TMC membrane maintained the rejection rate unchanged, while the permeability was increased by nearly 17 times, reaching 68.1—71.7L/(m²·h·bar). The Congo red (CR) rejection rate was 98%. The Na₂SO₄ and NaCl rejection rates were 12.4% and 2.7%, and the separation selectivity coefficients were 7.8 and 36.1, respectively.

Due to graphite's advantages such as abundant resources, high specific capacity and low lithium intercalation voltage, it is considered an important commercial anode for lithium-ion batteries (LIBs). However, the lower theoretical specific capacity of graphite limits further improvement in the energy density of LIBs. Therefore, in this study, a graphite/SiO composite anode was obtained by adding a small amount of silicon oxide (SiO) to graphite, which was then dispersed into a small amount of O,S co-doped double-walled carbon nanotube (O,S-DCNTs) aqueous conductive additive. The O,S-DCNTs were prepared by pre-oxidizing double-walled carbon nanotubes (DCNTs) in air and then mixing and calcining them with MgSO₄, possessing abundant nanoscale pore structures, high sulfur content and strong hydrophilicity. Battery performance tests revealed that the introduction of \mathrm{O},\mathrm{S}-\mathrm{D}\mathrm{C}\mathrm{N}\mathrm{T}\mathrm{s} significantly improved the specific capacity, rate capability and cycling stability of the graphite/SiO composite anodes. Additionally, its cycling stability was four times that of graphite/SiO anodes containing pure sulfur-doped carbon nanotubes (S-DCNTs). This improvement was mainly attributed to the highly dispersed \mathrm{O},\mathrm{S}-DCNTs, which can construct numerous conductive networks, provide abundant Li⁺ storage space and active sites, and address the issues of poor conductivity and large volume expansion coefficient of SiO, thereby significantly enhancing the electrochemical performance of the graphite anode. This work provided new insights and directions for the preparation and energy storage applications of high-performance anode materials.

In order to enhance the toughness of polylactic acid (PLA) melt electrospun fiber, a blend of polycaprolactone (PCL) and PLA was used as the electrospun material. PLA/PCL ultrafine fiber membranes were prepared using melt differential electrospinning. The effects of PCL and PLA ratios, electrospinning temperatures, voltages and rotational speeds of the roller on the fineness, mechanical properties, and hydrophilicity and porosity of the PLA/PCL melt electrospun fiber were investigated. It was found that under the condition of a 7∶3 ratio between PLA and PCL, a temperature of 230℃, voltage of 40kV and rotational speed of 2200r/min, PLA/PCL electrospun fiber achieved a minimum average diameter of (2.049±0.438)μm. The tensile strength increased by 115% to reach 13.68MPa while elongation increased by 21.5% to reach 175% compared to pure PLA melt electrospun membranes. Additionally, it was observed that porosity initially increased but subsequently decreased with an increase in collector roll speed for the PLA/PCL ultrafine fiber membranes. At a roller speed of 1400r/min, these membranes exhibited strong hydrophobic properties with a water contact angle measuring at approximately 144.3°along with remarkable porosity reaching up to 74.42%. This study was significant in efficiently fabricating ultrafine fiber membranes tailored to diverse requirements using environmentally-friendly techniques.

2,2-Dimethyl-1,3-propylene glycol (neopentyl glycol) shows a unique structure and excellent chemical properties and is widely used in medicine, textiles, coatings, petroleum and other fields. In this paper, the methods for the preparation of neopentyl glycol were briefly described, including the halogenated alcohol process, the formaldehyde disproportionation and the condensation hydrogenation of iso-butyraldehyde, and the catalyst and process system for the synthesis of the intermediate hydroxy-pivalaldehyde and neopentyl glycol in the condensation hydrogenation of iso-butyraldehyde were described in detail. By comparison of the performance of different catalysts and the catalytic hydrogenation process, the development direction of the neopentyl glycol synthesis process was proposed. Firstly, a solid basic catalyst with appropriate alkalinity, phase transfer function and reusability was required in the aldol condensation. Secondly, the hydrogenation of hydroxy-pivalaldehyde to neopentyl glycol required a pollution-free solid catalyst that could tolerate impurities and water and showed the ability to hydrogenate 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropionate. Thirdly, the intensified device should be designed in the catalytic hydrogenation process to improve the mass and heat transfer rate of the reaction and the total yield of neopentyl glycol. Fourthly, a formate recovery device was installed to improve economic benefits.

Pyrolysis has been recommended for the rapid treatment and disposal of typical organic solid waste by many ministries and commissions in China because of its high treatment efficiency, variety of resourcing products, lack of susceptibility to dioxin generation, and high effective carbon conversion rate. Addressing the issue of increasing carbon emissions caused by unstable process, poor product quality and inefficient heat utilization in treating organic solid waste by traditional pyrolysis system, this paper reviewed the novel low-carbon pyrolysis technologies and the preparation methods of high added value carbon-based materials. And it emphasized that carbon emissions from pyrolysis systems can be reduced by improving heat and mass transfer processes, regulating product generation, and producing high value-added products. In addition, the cases of combining pyrolysis technology with other organic solid waste treatment technologies were summarized, and methods for reducing carbon emissions in coupled systems were analyzed. Specifically, one was that carbon waste was reduced through cross utilization of products, resulting in the reduction of direct carbon emissions. The other was the energy utilization efficiency in combining pyrolysis system was improved by the optimization of energy flow paths, thereby reducing indirect carbon emissions caused by primary energy consumption. Finally, the application of life cycle assessment, process simulation technology and machine learning methods in optimizing carbon emissions of pyrolysis systems were explored. The overall optimization approach of pyrolysis systems with complex reaction processes and difficult real-time monitoring using computer simulation and artificial intelligence was sorted out, which provided new insights for reducing carbon emissions in pyrolysis system.

Microbial electrosynthesis system is a sustainable technology that uses microorganisms as biocatalysts to reduce carbon dioxide (CO₂) to organic compounds using renewable energy sources, which can help to mitigate atmospheric greenhouse gases and realize a low-carbon recycling bio-economy and industrial CO₂ bioconversion process. This paper describes the electron transfer mechanisms between the cathode and microorganisms in microbial electrosynthesis system, including direct and indirect electron transfer, of which hydrogen (H₂) mediated indirect electron transfer is the most studied electron transfer process. This paper also introduces the occurrence mechanisms of cathodic pure electrochemical hydrogen evolution reaction and biological hydrogen production in microbial electrosynthesis system, and elaborates on the interdependence and collaboration mechanisms between different microorganisms in the process of H₂ production and utilization and CO₂ reduction. The paper also focuses on the H₂ mediated indirect electron transfer process and proposes enhanced measures such as promoting the cathodic hydrogen evolution reaction, adding exogenous media and optimizing the reactor design in order to promote hydrogen production and CO₂ reduction process. This review provides theoretical basis and technological support for improving the electron transfer efficiency and target product yield of microbial electrosynthesis system.

Aromatic hydrocarbons (AHCs) are important raw materials of organic chemicals and blending components of gasoline, which are traditionally derived from petroleum route. Obtaining AHCs from renewable biomass resources is demanded due to the growing consumption of petroleum. Lignin, one of the components of biomass with rich aromatics, is a potential raw material for the production of AHCs. Efficient transformation of lignin to AHCs by catalyzed pyrolysis over HZSM-5 molecular sieve has attracted increasing attention, although this process faces low selectivity of target products, easy coke deposition on HZSM-5, and so on. The influences of HZSM-5 physicochemical properties and reaction conditions on the distribution of aromatic products were analyzed. Regulating the acidity, porosity, and mass transfer/diffusion of the catalysts, by metal addition, desilication, combining mesoporous catalysts, and assisted catalysis, enhanced the distribution of mono-aromatic hydrocarbons in bio-oils and the catalytic stability. Future development directions for this catalytic pyrolysis transformation were proposed including rational selection of the HZSM-5 modification strategy according to the target aromatic products, in-depth understanding of the catalysis and the carbon-accumulation mechanism.

Antibiotic resistance genes (ARGs) have been identified by the World Health Organization (WHO) as one of the serious health problems, and the contamination of ARGs in the environment can lead to the emergence of“superbugs”, which poses a great threat to the health of human beings and organisms. Therefore, this paper systematically described the hazards of ARGs and their diffusion mechanism in the environment, and summarized the contamination of ARGs in surface water, groundwater, soil and the current situation of wastewater treatment. The analysis showed that horizontal gene transfer played a key role in the spreading mechanism of ARGs. The pollution of ARGs in surface water was more serious than that of other water resources, and further caused the pollution of ARGs in soil and jeopardized the health of human beings. The current status of wastewater treatment system was analyzed, and although the advanced oxidation process is the best process for the removal of ARGs, the membrane bio-reactor (MBR) is more effective for removing the ARGs by virtue of its lower cost and good economic effect. Although the best removal effect of ARGs is the advanced oxidation process, the MBR has a better application prospect by virtue of its lower cost, good economic effect, and better treatment effect than the traditional activated sludge process. Therefore, combining the existing process and constructing a combined process has become the direction of future upgrading of wastewater treatment plants.

In order to explore the removal efficiency of coagulation-ozone oxidation technology on organic micro pollution in biotreated leachate, the biotreated leachate in Qingdao was taken as the experimental object, and the impact factors such as coagulant type, dosage and pH on organic matter on pollutant removal were analyzed. The enhancement effect of O₃, GAC/O₃ and UV/O₃ ozone oxidation systems on the removal effect of coagulant effluent were investigated. Further, the efficiency of coagulation-ozonation technology on the removal of antibiotic organic micropollutants from biotreated leachate was systematically evaluated. The results showed that with the dosage of polyferric sulfate (PFS) of 4g/L, pH=7, ozone flow rate of 80mg/min, and the reaction time of 30min, the removal efficiencies of COD and chroma (CN) of PFS-UV/O₃ are 86.27% and 99.06%, respectively, which are significantly better than PFS-O₃ and PFS-GAC/O₃. Under optimal conditions, coagulation-ozonation on antibiotics removal had good performance, removal rates of ofloxacin, enrofloxacin, sulfaguanidine and chlortetracycline during PFS-UV/O₃ process were 100%, 95.06%, 100% and 100%, respectively. Three-dimensional fluorescence parallel factor analysis showed that the characteristic peaks of humus fluorescent substances in biotreated leachate disappeared and decomposed effectively after PFS-UV/O₃ treatment. According to the technical and economic analysis, the energy consumption and cost of PFS-UV/O₃ treatment technology were 75.34kW·h/kg COD and 53.00CNY/kg COD, respectively. On the whole, PFS-UV/O₃ treatment technology was economically feasible and had potential application prospects.

The design lifespan of wind turbines is 20—25 years. The wind turbines put into operation around the year 2000 are about to be retired in China. With the increasing installed capacity of wind turbines year by year, the demand for resource utilization of retired turbines will surge in subsequent years. Due to the long length, light weight, and high strength characteristics, suitable scale recycle methods have not been found for wind turbine blades. Based on the assumptions of the current installed capacity of 440 million kilowatts and a composite material consumption of 16kg per kilowatt, the national wind turbine blade composite material market is approximately 7.04 million tons. The stacking density of wind turbine blades broken to the centimeter level is relatively small, only 39% of that of coal powder, and the transportation cost is relatively high. Based on a transportation distance of 200 kilometers, the transportation cost per ton of blades has reached 1200—1500CNY (excluding costs such as dismantling, cutting, and crushing). From an economic perspective, coupling with coal-fired boilers for co-firing is a promising large-scale recycle route. Wind turbine blades have good ignition and burn out characteristics. Starting at 224℃, weight loss occurs, and the characteristic temperatures during the ignition and burnout stages are 264℃ and 504℃, respectively. The ignition and burnout performance are better than those of coal. The residue of the burned blades is mainly glass fiber, and the elemental composition is mainly silicon, aluminum, calcium, and magnesium in the form of oxides. Wind turbine blades have the characteristics of high nitrogen, and low calorific value. A typical wind turbine blade has a dry nitrogen content of 0.82%, and an air-dry calorific value of 1849kcal/kg. There is a significant difference in the nitrogen structure between coal and wind turbine blades. Coal nitrogen mainly exists in the form of pyrrole nitrogen, accounting for 85%, while wind turbine blade nitrogen is mainly composed of amide structure, accounting for 90.6%. After being heated, amide structure nitrogen is more easily released into gas-phase nitrogen. The results of the co-firing experiment show that there is no significant change in pollutant NO emissions within a 10% co-firing ratio (weight ratio). According to a 10% co-firing ratio, a 300MW coal-fired boiler can tackle with the blade composite materials produced by 3052MW retired wind turbines annually. This means that the current coal-fired boiler can fully tackle with the solid waste generated by future retired wind turbines.

The cellulose based copolymer polycarboxylic acid water reducer (HEPCEs) was prepared from natural fiber by grafting etherification, nucleophilic substitution and free polymerization. The molecular structure of synthetic HEPCEs was analyzed by infrared spectrum and gel permeation chromatography. The performance of HEPCEs was tested from the aspects of paste fluidity and time varying fluidity. The mechanism of action of HEPCEs on cement slurry by testing molecular particle size, zeta potential and adsorption layer thickness was further investigated. The results showed that the suitable substitution amount of modified cellulose polyether DBHECs in HEPCEs was 5%—10%. Excessive substitution of DBHECs would lead to branch chain entanglement and hindering the anchoring of carboxylic acid groups, causing a decrease in the performance of the water reducing agent. The introduction of appropriate substitution of cellulose structure can effectively further improve the performance of water reducing agents while maintaining good adsorption performance. From experiments with time variation, HEPCEs-5 indicated good performance and exhibited a certain degree of sustained release effect.

To understand the effect of salt on the performance and mechanism of electrocatalytic degradation, the performance test of electrocatalytic oxidation of an industrial wastewater was carried out. The effect of salt on the electrocatalytic oxidation was analyzed by investigating the COD (chemical oxygen demand) removal efficiency under different salt contents (0.1%—2.0%), current densities (5—20mA/cm²), plate spacing (0.5—1.5cm) and pH (4—10). The production of active species in different salt-containing systems was analyzed by electron paramagnetic resonance (EPR/ESR) technique. In addition, the service life of the electrode was evaluated by a rapid test method. The results showed that the maximum COD removal efficiency of the electrocatalytic system without salt and with the addition of NaCl and Na₂SO₄ were 58.4%, 84.7% and 63.3%, respectively, and the corresponding current efficiencies were 15.4%, 19.6% and 16.7%. A quadruple peak intensity of 1∶2∶2∶1 was found in the original electrocatalytic system, which was consistent with the characteristic peak of \bullet \mathrm{O}\mathrm{H}. The characteristic peaks of \bullet \mathrm{O}\mathrm{H}、¹O₂和·{\mathrm{O}}_{\mathrm{2}}^{-} were found in the electrocatalytic system with Na₂SO₄, while similar characteristic peak of chlorine-containing free radicals were additionally found in the electrocatalytic system with NaCl. Under the enhanced test conditions, the electrode lifetime was 11460s. NaCl was beneficial to increasing the maximum COD removal rate with high current efficiency and enriching the types of active species.

The capture of CO₂ from flue gas is commonly achieved using chemical absorption processes. The process requires optimization to enhance CO₂ removal efficiency while minimizing energy consumption. This paper used Aspen Plus simulation to model both the typical amine-based CO₂ capture process and an optimized low-energy, high-efficiency CO₂ capture process. The effects of MEA + H₂O and MEA + MDEA + H₂O absorbent circulation and absorption temperature on CO₂ removal rate and energy consumption of lean solution regeneration were investigated. The results revealed that both the typical amine-based process and the low-energy, high-efficiency process met the design requirements of capturing CO₂ with a purity of ≥90% and a removal efficiency of >90%, while keeping energy consumption below 3.0GJ/tCO₂. The optimal solvent circulation rates were 60m³/h for MEA+H₂O and 65m³/h for MEA+MDEA+H₂O. The absorption temperature range was 40—45℃. Under the same absorption agent and circulation rate, both processes achieved similar CO₂ removal rates and recovery efficiencies. The low-energy, high-efficiency CO₂ capture process reduced the energy consumption for lean liquid regeneration by 0.13GJ/tCO₂. After the optimization of CO₂ capture process, equipment investment and utility consumption costs could be significantly reduced.

The current energy development strategy of developing simultaneously oil and gas, as well as conventional and unconventional energy sources, effectively promotes the development process of shale oil, and the attention to its efficient and safe gathering and transportation process technology has been significantly increased. In this paper, the basic physical properties of JH shale oil were determined by indoor experiments, and its characteristics of low freezing point, low density, high wax content, high number of light components, no asphaltene, few colloids and weak wax crystal structure were identified. The wax crystal structure is easy to be destroyed during the gathering and transportation process, which will lead to the rapid decrease of dynamic viscosity near the freezing point. When the temperature of oil gathering is lower than the freezing point, the dynamic yield stress is significantly lower than the static value after stopping the transportation. After stopping the transportation, more wax crystals are precipitated during the static cooling process, which leads to the rapid recovery of condensate structural strength; under the condition of no temperature drop, the structural strength recovery is very slow, and the dynamic yield stress obtained after stopping the transportation for 12h at 9℃ below the freezing point is only 8.5% of the static value. In order to ensure the transportation safety, it is necessary to avoid the restart operation under the condition of low ground temperature or large temperature drop after stopping the transportation, and if necessary, intermittent startup can be used to reduce the yield stress of condensate, so as to ensure the restart safety.

This study investigated the feasibility of butyric acid production from kitchen waste using butyric acid fermenting bacteria, Clostridium tyrobutyricum. The extraction of fermentable sugars from kitchen waste was controlled through various pretreatment methods involving acid, alkali, and temperature adjustments to optimize the hydrolysis of polysaccharides. Under the optimized conditions of 1.5% (mass concentration) sulfuric acid, 121℃, and 1h, the polysaccharide conversion efficiency reached 62.8%. Following acid pretreatment, the cellulose content in the kitchen waste was enzymatically hydrolyzed more effectively, leading to an enhanced conversion efficiency of polysaccharides. The potential of butyric acid production viaClostridium tyrobutyricum fermentation, augmented by carbon dots, was assessed using the acid-pretreated effluent from kitchen waste as a substrate. Results indicated a 12% increase in butyric acid yield with the addition of carbon dots compared to the control group without them, while the acetic acid content decreased by 27%. Electrochemical analyses demonstrated a 11% increment in the capacitance of Clostridium tyrobutyricum and a 12.6% reduction in resistance upon the introduction of carbon dots. This observation suggested that the inclusion of carbon dots enhanced the electroactivity of the bacterium, potentially accelerating the electron transfer rate within the intracellular Rhodobacter nitrogen fixation (Rnf) complex and elevating the intracellular NADH/NAD⁺ coenzyme ratio. Consequently, this enhancement could facilitate the conversion of acetic acid to butyric acid. This study is anticipated to offer practical methodologies and theoretical foundations for the effective utilization of kitchen waste resources.

As an important means of carbon capture in flue gas, chemical absorption has been widely used in various demonstration projects. Among them, the sodium alkali method has the advantages of low volatility, low toxicity and low cost compared to the current mainstream absorption method. In this paper, to deal with the acidic gas CO₂ in flue gas and the desulfurization wastewater containing Na₂SO₄ after dry desulfurization and SO₂ removal, electrolytic Na₂SO₄ and CO₂ capture by NaOH aqueous solution were coupled to analyze the electrolytic efficiency and NaOH yield under different conditions, explore the absorption effect of CO₂ capture in absorption equilibrium experiment and spray tower, and compare the crystallization amount of NaHCO₃ under different conditions. The electrolysis efficiency and NaOH yield under various conditions were analyzed. The CO₂ absorption equilibrium experiment showed that the electrolytic product NaOH had a higher absorption amount and absorption rate than Na₂CO₃, and MEA could further enhance the CO₂ absorption effect of NaOH. When the temperature was 50℃ and the liquid-gas ratio was 167, the CO₂ capture effect in the spray tower was optimal with an absorption rate of 98.67%. Fine crystalline rod-shaped NaHCO₃ powder can be obtained and the maximum crystallization amount can reach 22.447g.

In order to clarify the treatment target for high-risk and pungent odor substances, the odor threshold (OT) and the lowest concentration of interest (LCI) data were measured and collected, and the odor activity value (OAV) and risk value (R) were calculated and evaluated, based on the systematic analysis of odor substances in fiberboards. The results showed that benzene series, terpenes, acetic acid, hexaldehydes and other small molecules were the most odor substances released in fiberboards. Although acetic acid (strong, pungent, similar smell to vinegar ), propionic acid ( spicy vinegar odor), styrene (pungent, similar smell to rubber), p-, m-xylene ( irritating aromatic odor ), 1-butanol ( alcohol spicy odor ), o-xylene ( irritating aromatic odor ), benzaldehyde ( bitter almond odor ), and furfural (similar smell to benzaldehyde ) had irritating odor, the main odor substances (OAV>1) werealdehydes such as hexanal, nonanal, pentanal, and heptanal, and terpenes such as longifolene and \alpha-\mathrm{p}\mathrm{i}\mathrm{n}\mathrm{e}\mathrm{n}\mathrm{e}. The reduction of aldehydes and terpenes was the main way to reduce the pungent odor of fiberboards. The risk value of odor substances was related to both the amount of release and the LCI value. Although fiberboards contained low and medium toxic substances such as 2-methylnaphthalene and xylene, the risk values of these substances were far less than 1.

The further extraction of lithium ions from waste lithium-ion battery recycling solutions offers both economic and environmental benefits. β-diketone solvent extraction systems have garnered extensive attention due to their excellent lithium extraction capabilities. However, the limited variety of β-diketone extractants currently available results in certain selection constraints. This study conducted theoretical calculations of the molecular surface electrostatic potential of the extractant and the Gibbs free energy change of the lithium extraction reaction using Gaussian 16 and Multiwfn software. The results indicate that substituents such as —NO₂, —CF₃, and —CN can enhance lithium extraction performance by altering the electrostatic potential extrema of the β-diketone's van der Waals surface. Based on this theoretical foundation, a selective lithium extraction agent, IPE-23, was developed. The impact of operational factors such as extractant concentration, temperature, phase ratio, and base addition was investigated using lithium extraction efficiency, separation ratio, extraction phase separation, and the loss of extractant in the aqueous phase(measured by the chemical oxygen demand in the aqueous phase) as evaluation metrics. Through a process of three-stage countercurrent extraction, three-stage countercurrent washing, and CO₂ acidification stripping, the lithium extraction rate reached 97%, with a distribution ratio D_Li of 21.90 and a lithium-sodium separation factor of 423.85. The pH of the remaining liquid was 11.3, with a COD of 675.2mg/L, and the lithium concentration in the stripping solution reached 6.66g/L. This study provides technical reference and theoretical support for the efficient recycling and reuse of lithium resources from lithium-containing wastewater.

Aluminum-based catalyst is the most demanding and widely used catalyst in petroleum refining industry. The comprehensive economic benefits of industrial catalytic process can be greatly improved by recycling the discarded aluminum-based spent catalyst support that can not be used any more. In this study, the aluminum support from spent Pt-Sn/Al₂O₃ catalyst was recovered by“sodium roasting-weak alkaline leaching”to obtain NaAlO₂ solution, and NaAlO₂ was prepared into mesoporous alumina with high specific surface area and large pore volume by reverse precipitation. By changing the parameters such as roasting temperature, mass ratio of raw materials and leaching pH, the leaching rate of aluminum was optimized. Under the conditions of roasting temperature of 450℃, mass ratio of 1.2 and leaching pH of 8.5, the leaching rate of aluminum could reach 99.9%. Mesoporous alumina was prepared from recovered NaAlO₂ solution, and prepared samples were characterized by X-ray diffraction (XRD), Brunner-Emmet-Teller (BET) and particle size analyzer. The results show that under the conditions of calcination temperature of 500℃, aging time of 12h and reaction pH of 10, the specific surface area of mesoporous alumina synthesized is 284.19m²/g, the pore volume is 0.47cm³/g, and the average pore diameter is 6.65nm. The pore size distribution is uniform and the particle uniformity is good. The specific surface area and particle size of the regenerated alumina meet the national standard of alumina (GB/T24487—2022).

The structure-function relationship between the type and structure of the oil shale ash-based zeolite and its ability to adsorb dyes is unclear. NaP1, NaX and NaA zeolites were prepared from Beipiao oil shale ash (BPA) and used to adsorb methylene blue (MB). The effects of zeolite dosage, initial MB concentration, pH, adsorption temperature and time on the MB adsorption performance were investigated, and the adsorption mechanism was revealed. The structure-function relationship between the type of zeolite and its ability to adsorb MB was explored. The results showed that the specific surface area and pore structure of the zeolite have great effects on its adsorption capacity. Under the optimal adsorption conditions, the MB removal percentages by NaP1, NaX and NaA zeolites are 99.7%, 94.5% and 96.5%, respectively. The synthesized zeolites have excellent recyclability. The adsorption processes conform to the pseudo-second-order kinetic and the Langmuir isothermal adsorption models. The adsorption thermodynamics results show that the MB adsorption on the NaP1 zeolite is a spontaneous endothermic process of increased entropy while that on the NaX and NaA zeolites is a spontaneous exothermic process of decreased entropy. The study of adsorption mechanism showed that electrostatic attraction, hydrogen bond and pore diffusion are the main driving forces during the MB adsorption on the zeolites. This work can provide valuable practical and theoretical reference for the efficient utilization of oil shale ash and low-cost treatment of dyeing wastewater by adsorption method.

Biotechnology, especially in the field of biomanufacturing, has become an important competitive highland for technological innovation between China and the United States. The United States has clearly identified biomanufacturing as its main strategy for the next 20 years. Developing biomanufacturing and bioeconomy has become an important strategy for promoting sustainable development globally, addressing a series of issues such as environmental protection and carbon emissions. This article compared the clear goals of biotechnology and biomanufacturing in the United States and relevant policies in the field of biomanufacturing in China. From the upstream, industry and manufacturing fields of biomanufacturing as well as the market and application fields, it analyzed the competitive focus of China and the United States in the field of biomanufacturing as well as the competitive advantages and disadvantages of China in the field of biomanufacturing compared to the United States. Possible countermeasures were proposed for some issues. Through analysis, it was beneficial to deepen the profound understanding of the opportunities and challenges faced by researchers in this field in China's biomanufacturing field, and it also had reference value for understanding and innovating the cultivation of future related scientific research and industrial talents.