At present, most of the oilfields in China are in middle and late stages of development and it is necessary to improve the oil recovery by tertiary enhanced oil recovery technology. Deep and ultra-deep reservoirs, due to the high temperature and high salt characteristics, make it difficult for a single oil displacement system to meet the needs of current oilfield exploitation. Based on this phenomenon, the research progress and application status of various types of temperature and salt resistant oil displacement systems at home and abroad were reviewed in this paper, including surfactant flooding, polymer flooding, foam flooding and nanofluid flooding. By expounding the structure and performance of these oil displacement systems, analyzing the action mechanism and oil displacement effect, and combining with the actual application effect in the field, the temperature and salt resistant oil displacement systems in deep and ultra-deep reservoirs were summarized in detail, which laid the foundation for the key research direction in the future. The results showed that for deep and ultra-deep reservoirs, the research on temperature and salt-resistant oil displacement systems can effectively improve the oil recovery in the later stage of reservoir development and ensure the comprehensive production of residual oil. The future research directions for temperature and salt resistant oil displacement systems should focus on the following aspects. Firstly, it can reduce the interfacial tension to a greater extent. Secondly, it was to reduce the cost and use the lowest cost to achieve better production efficiency to the greatest extent. Thirdly, it was to study the synergistic performance between different types of oil displacement agents.

Carbon dioxide pipeline transportation is the key link of carbon capture, storage and utilization technology. Accelerating the development of carbon dioxide pipeline transportation technology and promoting the construction of carbon dioxide pipeline are very important to realize the "dual carbon" strategy. This paper discussed the development of carbon dioxide pipeline engineering, the present situation of carbon dioxide pipeline transportation technology and the development suggestions of carbon dioxide pipeline transportation technology. Firstly, the construction of carbon dioxide transportation pipelines at home and abroad was compared and analyzed. Then, the development status of carbon dioxide pipeline transportation technology was explored in terms of carbon dioxide flow components, pipeline transportation technology, pipeline materials, corrosion and protection, leakage and diffusion, and standards and specifications. Finally, on this basis, combined with the conditions of our country, future development suggestions of carbon dioxide pipeline transportation technology were put forward. The research results of this paper can provide support and reference for the development and application of carbon dioxide pipeline transportation technology in China.

The motion and deformation characteristics of discrete oil droplets in a pipe with variable cross-section was one of the core problems in revealing the mechanism of two-phase flow. The discrete oil droplets inside the sudden contraction and sudden expansion round pipe were taken as the research object, and numerical simulation and high-speed camera experiment were combined to study the motion and deformation characteristics of oil droplets inside the sudden contraction and sudden expansion round pipe under different inlet Reynolds numbers. The results showed that in the sudden contraction and sudden expansion round pipe, at conditions of the same Reynolds number, as the particle size of the discrete oil droplet increased, the pressure at the inlet end of the pipe and in the sudden construction zone increased, the pressure rose faster in the area of sudden expansion, and the largest deformation of oil droplets was in the thin pipe section. Simultaneously, when the particle size of oil droplets unchanged, the deformation of discrete oil droplets in the pipe increased with the increase of inlet Reynolds number, and the initial broken position of the oil droplets in the pipe was closer to the shoulder of the protruding axis and the degree of brokenness was more intense. What's more, when Re=6.3×10³, the deformation of oil droplets reached the maximum value of 0.84 and the initial crushing position was 33.2mm away from the shoulders of sudden expansion. In addition, the motion, deformation and fragmentation laws of discrete oil droplets in the sudden contraction and sudden expansion round pipe under different inlet Reynolds numbers and oil droplet sizes were obtained. Thus, this paper provided theoretical reference for strengthening oil-water two-phase flow mixed transport in surface crude oil gathering and transportation network.

The flow characteristics of the punched and four-pitched blade combined impellers in the stirred tank were simulated by using large eddy simulation based on computational fluid dynamics (CFD) and the simulation results were validated by the results of particle image velocimetry (PIV) experiments. The effects of different rotational speeds, installation height of impellers, and punched hole diameter on the flow field characteristics were investigated. The research results showed that the increasing of rotational speed can enhance the pumping effect of the lower blade and then promoted the mixing effect of the flow field. However, the excessive increasing of rotational speed can cause chaos in the flow pattern, and the simulation results showed that the optimal speed was N=100r/min. The increasing of the installation height of impellers would improve the velocity distribution in the top area of the tank. When the ratio of installation height of impellers to vessel diameter was 0.29, a vortex favorable for mixing was formed in the flow field, and the distribution of flow velocity in the top and lower areas was appropriate, indicating a better distance from the bottom. The connection flow between two blades was mainly affected by the punched hole diameter. When the punched hole diameter was 4mm, the connection flow in the mixing tank was more stable and the overall high-speed zone area distribution was more appropriate, which can promote the overall circulation effect in the mixing tank. The research results can provide a reference for the application of punched and four-pitched blade combined impeller in practical industrial processes.

"Liquid-vapor separation" was applied in plate condenser with zeotropic mixtures R134a/R245fa. The impact of refrigerant mass flows, bubble point temperatures and the compositions of mixtures (mass fractions) on the heat transfer performance of the liquid-vapor separation plate condenser were examined. A comparison with experimental data from a conventional plate condenser was conducted to highlight the thermodynamic performance of zeotropic mixtures. The results showed that a high proportion of low-boiling-point refrigerant improved liquid-vapor separation, achieving a maximum liquid separation efficiency of 99.74%."Liquid-vapor separation" effectively adjusted the compositions of the zeotropic mixtures, increasing the proportion of low-boiling-point refrigerant after separation. Compared with conventional plate condenser, the liquid-vapor separation plate condenser exhibited a 5.6%—46.9% increase in heat transfer coefficient. It was inversely proportional to refrigerant mass flows and directly proportional to bubble point temperatures. The pressure drop decreased by 12.6%—44.3%, less affected by refrigerant mass flows and bubble point temperatures, a higher proportion of low-boiling-point refrigerant in the zeotropic mixtures resulted in a smaller pressure drop.

A three-dimensional, transient gas-solid two-phase fixed bed microwave heating model was established according to the actual experimental setup. The microwave heating effects under four different catalyst particle stacking modes (simple, diamond, cubic, hexagonal) were simulated and calculated, considering the influence of different inlet gas velocities and microwave heating powers. The results indicate that the heat transfer efficiency of the fixed bed reactor is enhanced under microwave heating, with the diamond stacking mode exhibiting the best heat transfer effect among the four stacking modes. The microwave field has a certain directionality, with the highest electric field intensity along the z-axis, resulting in pronounced hotspot effects between particle contact points. In the horizontal direction, there is no strong electric field formed in the y-axis direction perpendicular to the microwave feeding inlet. Based on the diamond stacking model, the calculation results for inlet gas velocity and microwave power suggest that the inlet gas velocity can change the heating rate and the time required to reach equilibrium temperature, while the microwave power only affects the final temperature. As the inlet gas velocity increases, the temperature difference between particles decreases. These findings provide theoretical support for solving the problem of poor heat transfer efficiency in traditional fixed-bed reactors during strong endothermic reactions.

Phosphogypsum (PG) was used as raw material, Ca²⁺ was leached from PG by sodium D-gluconate, and then CO₂ was captured by the leaching solution to prepare calcium carbonate powder. The effects of liquid-solid mass ratio and reaction temperature on leaching rate of Ca²⁺, as well as the effects of ammonia addition and carbonization time on the conversion rate of Ca²⁺ were studied. The morphological characteristics and formation mechanism of carbonized products under different ammonia additions and carbonization times were analyzed by scanning electron microscope, X-ray diffraction and particle size analysis. The results showed that the Ca²⁺ leaching rate increased with the increase of liquid-solid mass ratio and the Ca²⁺ leaching rate of PG increased from 91% to 100% when the reaction temperature decreased from 85℃ to 25℃. Under the reaction temperature of 20℃ and CO₂ concentration of 20%, the calcium carbonate particle size distribution interval showed a decreasing trend with the increase of ammonia addition and carbonization time, and the Ca²⁺ conversion rate was increasing. When the amount of ammonia added was 20mL and the carbonization time was 150min, the conversion rate of CaCO₃ was up to 92.7% and the carbonization product was rounded rhombic calcite with the peak particle size as well as the median particle size of 1.5μm and 5μm, respectively. The increase of ammonia addition in the reaction solution was more conducive to the formation of calcite, and the increase of carbonation time promoted the formation of spherulite aragonite. However, the number of carbonization products decreased abruptly with the decrease of Ca²⁺ in the reaction solution. Due to the poor stability of the generated spherical chalcocite and the role of the organic solvent D-gluconate sodium solution, the reaction products would undergo dissolution and recrystallization, and form rounded rhombic calcite with a small and uniform particle size. This study provided a new process method for the comprehensive utilization of PG as well as the capture of CO₂ and preparation of calcium carbonate powder.

Ethyl acetate, ethanol and water can form a system with three binary and one ternary azeotropes. The aim of this study is to use ionic liquid (IL) as the extractant to break these azeotropes for effectively separating the ternary system. Based on the COSMO-RS model and the viscosity prediction model, selectivities, capacities and viscosities of 65 ILs were calculated. It was found that 1-butyl-3-methylimidazolium acetate ([BMIM][Ac]) was barged to the forefront as the extractant among 65 ILs. The vapor liquid equilibrium (VLE) experiments of ethyl acetate (1)+ethanol (2)+water (3)+selected IL (4) system were conducted. It was confirmed that the [BMIM][Ac] can effectively influence and break all the azeotropes in this system, proving the screening result. Correlation accuracies of the VLE data by the NRTL and UNIQUAC models were 1.69% and 2.20% of RMSDs, respectively. The slight errors emphasized the reliability of correlation results. The mechanism of separation for this ternary system with IL was qualitatively and quantitatively analyzed by quantum chemical calculations. It was showed that the [BMIM][Ac] formed weak hydrogen bond interactions with ethyl acetate (-8.22kcal/mol, 1kcal≈4.186kJ) and strong hydrogen bond interactions with ethanol and water (-15.83kcal/mol and -16.14kcal/mol, respectively). Based on the correlated model parameters, an extraction distillation process was simulated and optimized for separating the ethyl acetate+ethanol+water system with the selected IL as the extractant. It was achieved that the mass fractions of ethyl acetate, ethanol and water can all reach 0.999. The research result demonstrated the industrial feasibility of separating this ternary azeotropic system with [BMIM][Ac] as the extractant.

Based on the field synergy principle, a pin-fin multi inclined jet microchannel heat sink for efficient cooling of electronic components was proposed. The impacts of inclined jet angle (θ), relative pin fin height (α), and crossflow on the flow and heat transfer characteristics of the heat sink are investigated through numerical simulations. The results showed that, pumping power firstly decreased and then increased with the increase of jet angle, and thermal resistance monotonically decreased with the increase of jet angle and reached the minimum value at θ=150°. The pin fin can destroy the helical flow caused by the jet and strengthen the heat transfer in the crossflow region, and the combination of the pin fin and the inclined jet can achieve better heat transfer performance. To comprehensively study the overall performance of the pin-fin inclined jet impingement microchannel, radial basis function neural networks and the NSGA-Ⅱ genetic algorithm were employed for multi-objective optimization of thermal resistance and pumping power. Under the same pumping power, the optimized thermal resistance decreases by 26.0% compared to that of the smooth multi vertical jet microchannel, while under the same thermal resistance, the optimized pumping power decreases by 94.6%. Furthermore, the thermal resistance and pump power of the optimal compromise solution selected by TOPSIS combined with the entropy weighting method are 0.055 K/W and 0.56W, respectively.

In the methanol to olefins (MTO) process, the defects of the original design leads aromatic hydrocarbons and heavy components in the process water cannot to be proposed by steam, resulting in a certain amount of suspended and colloidal pollutants in the purified water at the bottom of the sewage stripper. The high content of chemical oxygen demand (COD) has become an obstacle to the reuse of wastewater. In view of the shortcomings of the current MTO wastewater treatment technology, this paper proposed a new type of cyclone regeneration microchannel separator series process based on field experiments, which was used to classify and treat MTO purified water. The primary separator was used to remove non-dissolved pollutants in purified water and reduce some COD content, and the secondary separator was used to deeply remove COD. The first-stage adsorbent MC-1 and the second-stage adsorbent MC-4 had the best adsorption efficiency, and the cross-sectional flow rate of the bed was most suitable to be controlled at 2.5mm/s. The average turbidity of the purified water after treatment was reduced from 18.3NTU to 2NTU, the suspended solids content was reduced from 18mg/L to 2.79mg/L, the separation efficiency was basically higher than 80%, and the chemical oxygen demand COD content was reduced by 318mg/L on average. The separation and purification effect was obvious. The purified water after treatment can replace the turbine condensate for olefin separation water washing tower or reuse to other water units. The process had the characteristics of low cost, high removal efficiency of suspended particles, colloidal particles and small molecular organic matter, and complete regeneration of separation media. It effectively solved the problem of difficult reuse of wastewater in the process of methanol to olefins (MTO). It was of great significance to reduce environmental pollution and save water resources.

A novel multistage series gas separation system was proposed according to the molecular exchange flow effect. Meanwhile, a mathematical model describing the separation performance and energy consumption of the proposed system was established using the "pipenet method" and the effective energy (exergy) analysis. Moreover, it was studied that the impact of operating parameters (i.e., temperature difference, Knudsen number and production rate) and the structural parameter (i.e., number of separation units in series) on the evaluation indices of the system performance (i.e., molar concentration and recovery rate of the target component in the final product gas) and energy consumption (i.e., minimum separation work and total energy consumption) when separating Ne-Ar mixtures with the proposed system. The results indicated that the molar concentration and recovery rate of the target component, minimum separation work, and total energy consumption increase with the rise of the temperature difference, and first increased and then decreased with the rise of the Knudsen number. The molar concentration and recovery rate of the target component, minimum separation work and total energy consumption reach the peaks at the Knudsen number approximately equaled to 1.5. With the rise of the production rate and the number of separation units in series, the molar concentration of the target component decreased while the recovery rate increased. The minimum separation work and total energy consumption increased with the rise of the number of separation units in series but decreased with the rise of the production rate. The molar concentration of the target component up to 98.55% can be achieved at the temperature difference of 60K. Just 5 separation units were required to obtain a target component recovery rate of 90.29% at the production rate of 0.1, with the corresponding minimum separation work of 1.56GJ/t Ne and the total energy consumption of 1.62GJ/t Ne. The proposed system was applicable to various gas separation scenarios owing to its modular structure. Additionally, it can directly utilize low-grade thermal energy for cascaded energy utilization, representing an innovative gas separation technology that aligned with the current requirements for green development.

Mass exchange network is an important way to recover pollutants or impurities efficiently and economically in process systems, the small-scale characteristics of which have certain limitations on their solution domain and global optimization performance. Based on the theory of mass transfer and energy transfer comparison, this paper assumed the tray mass providing an effective mass transfer of per unit height tray, established the comparison relationship between tray column tower and heat exchanger. On this basis, the small-scale mass exchange network was analogized to the generalized heat exchanger network. Furthermore, the node-based non-structural model and the random walk algorithm with compulsive evolution were used to globally optimize the generalized heat exchanger network. Finally, the optimal generalized heat exchanger network was regressed to mass exchanger network to make it satisfy the mass transfer feasibilities. The example analysis showed that the method can effectively expand the search space of mass exchanger network, thus to improve the diversity of stream matching and global optimization performance. Meanwhile, flexibly adjusting the analogy scale and coordination coefficient can further enrich the optimization path of MEN, and improve the quality of the optimal solutions. The obtained optimal solutions for the R2S3 and R2S2 examples were both superior to the best solutions in the literature.

Short-circuit flow is a crucial factor that affects the separation efficiency of hydrocyclones. However, there is limited research on the form and calculation methods of short-circuit flow in dynamic hydrocyclones. In this study, a numerical simulation method was proposed to analyze the radial velocity variations and streamline at the overflow pipe outlet of dynamic hydrocyclone. Taking the dimensionless high sensitivity structural parameters of the dynamic hydrocyclone as input indicators and the short-circuit flow rate ratio obtained from numerical simulation as the response target, the calculation model between the dimensionless structural parameters and the short-circuit flow rate ratio were established by the response surface method. Based on the established model, structural improvements were made to a dynamic hydrocyclone with a single tube processing capacity of 120m³/h. The improved design resulted in a 59.6% reduction in short-circuit flow rate, a 10.4% increase in separation efficiency. Subsequently, a prototype of the improved dynamic hydrocyclone with a single tube processing capacity of 120m³/h passed the experimental verification on an offshore oil platform. The average error between the experimental separation performance and the simulated predicted separation efficiency was only 4.9%.

In order to make the oxygen thermal entrained-flow calcium carbide reactor meet the design requirements of high calcium carbide yield and low energy consumption, the burner layout parameters and operating parameters of the designed calcium carbide reactor were optimized by Fluent software. Firstly, only the non-premixed combustion model of pulverized coal was added to the reactor to study the uniformity of temperature field in the reactor. Under the condition that the number of nozzles was 4 and the particle size of pulverized coal was 120 μm, the orthogonal experiment of three factors and three levels was designed with the highest uniformity of temperature field as the goal. The response surface method was used to optimize the layout parameters of the nozzle (nozzle axial angle, nozzle tangential angle and nozzle height). The result showed that changing the layout parameters will have a greater impact on the uniformity of the temperature field. The optimal layout parameters were the axial angle of 46°, the tangential angle of 32°, and the nozzle height of 0.56m. The calculated temperature field uniformity was 61.25%, which was 28.79% higher than the original model, and the optimization effect was obvious. Then, in the reactor with the optimal structure, a double reaction model of pulverized coal non-premixed combustion and calcium carbide synthesis was added. With the highest yield of calcium carbide as the goal, a three-factor three-level orthogonal experiment was designed. The response surface method was used to optimize the operating parameters of the reactor (feed particle size, feed temperature and oxygen temperature). The optimized operating parameters were beneficial to the improvement of the yield. The optimized operating parameters were: feed particle size 138μm, feed temperature 1432K, oxygen temperature 769K, and calcium carbide yield 58.36%, which was 16.68% higher than that before optimization.

With the rapid development of green renewable energy, proton exchange membrane (PEM) hydroelectrolysis technology has attracted much attention as a key link between renewable energy and hydrogen energy. In this paper, the working principle and technical status of anodes in PEM electrolyzers and the research progress of low iridium catalysts are reviewed. Even though PEM electrolysis technology has broad prospects, but the scarcity and the high price of iridium using in anode catalyst restrict the popularization of PEM electrolysis technology. The research of low iridium oxygen evolution (OER) catalysts with high activity and stability becomes much more important for the development of PEM electrolysis technology. At present, the low iridium catalysts mainly focus on the doped and supported catalysts. These two types of low iridium catalysts show higher catalytic activity than iridium oxides. Several low iridium catalysts reported recently, such as double perovskite, GD-doped IrO₂, IrNiO _x with core-shell structure, IrO _x /ATO etc., are described in this paper. The main challenges for increasing the activity and stability of low iridium catalysts are summarized, such as the crystal phase instability of doped catalysts and the utilization of Ir in supported catalysts. Finally, some suggestions and prospects are summarized in order to promote the activity and stability of low iridium catalysts supporting the future development of PEM electrolysis technology

Distributed cogeneration of heat and electricity using solid oxide fuel cells (SOFC) is an important method in building a “clean, low-carbon, safe, and efficient” modern energy system to improve energy supply and ensure energy consumption security. Hydrogen is the most important and most suitable fuel for SOFC. However, the application of SOFC in distributed cogeneration scenario is limited by the challenges in hydrogen storage and transportation technology, which has high cost and significant safety hazards. Using liquid methanol as a hydrogen storage carrier for on-site reforming to produce hydrogen is expected to achieve a breakthrough in the hydrogen supply of SOFC in distributed cogeneration scenario. In this paper, the progress of methanol steam reforming reactor for SOFC at home and abroad are introduced. The hydrogen source supply mode is outlined. And the structure, function and heating mode of methanol steam reforming reactor, which is the core equipment for on-site hydrogen production through reforming, have been summarized. The operation parameters and structural parameters affecting the reforming performance of the reactor are analyzed. And the characteristics of the integrated system of reactor and SOFC are introduced. The future development directions of methanol steam reforming reactor for SOFC include the design of high-power methanol steam reforming reactor, the study of hydrogen production mechanism and the heat and mass transfer characteristics of high-power methanol steam reforming reactor, and the performance of using methanol steam reforming reactor to directly supply hydrogen for medium temperature solid oxide fuel cells to generate power.

Mercaptans are hazardous components commonly found in natural gas. Compared to hydrogen sulfide (H₂S) and carbon dioxide (CO₂), mercaptans exhibit lower removal efficiency in the conventional amine-based absorption processes because of their lower acidity and reactivity. Herein, the solubility prediction methods based on COSMO-RS theory were employed to identify a kind of alternative solvents with promising dissolving performance. The removal efficiency of these solvents for methyl mercaptan was evaluated on a custom-made absorption apparatus using simulated high-acid natural gas as the feedstock. Furthermore, we employed quantum chemistry calculation to elucidate the mechanisms for dissolution of methyl mercaptan into these solvents. Present study demonstrates that the alkoxypropylamine solvents have effective solubility for methyl mercaptan, and the contents of hydrogen sulfide and organic sulfide can be reduced from 5% and 933mg S/m³(standard condition) in the raw gas to 0 and less than 20mg S/m³(standard condition) in the purified gas, respectively, by using alkoxypropylamine solutions with a concentration of no less than 20%(mass fraction) under the gas-to-liquid ratio of less than 250. The sulfur content of purified gas can meet the specification for Chinese first-grade commercial 《Natural Gas》 (GB17820—2018). Analyses on intermolecular interactions between the solvent and solute indicate that methyl mercaptan molecules can be captured in alkoxypropylamines via strong hydrogen bonding and big-area van der Waals interaction.

The advantage of separation gas mixture via hydrate method includes clean, efficient and safe. We examined the synergistic effect of sII hydrate promoters, semi-cage hydrate promoters and amino acids on hydrate formation of 30% CH₄/70% N₂ mixture with magnetic stirring to solve the problem of gas storage capacity, involving four thermodynamic promoters [tetrahydrofuran (THF), cyclopentane (CP), tetrabutylammonium bromide (TBAB) and tetrabutylammonium fluoride (TBAF)], with a 0.06% Tryptophan (Trp) as kinetic promotor added in every experiments system of hydrate formation. The results of the study showed that THF-TBAF, CP-TBAB and CP-TBAF systems continued the growth of hydrate and enhanced the gas uptake comparing the THF or CP as the single thermodynamic promotor system. However, the hydrate growth rate was decreased for adding semi-cage thermodynamic promoters. The average gas consumption in CP-TBAF system was the highest among the mixed promotors systems and increased by 1.33 times within 3 hours. Meanwhile, the normalized gas uptake rate was decreased by more 3 times. The N₂ entering the hydrate phase in THF-TBAB-Trp and THF-TBAF-Trp system was so more that separation effect was lower than THF-Trp system. CP and TBAB/TBAF mixture had the synergistic effect on the process of separation CH₄/N₂via hydrate technology for CH₄ of stronger selectivity. The improving effect on hydration separation mixed gas in CP-TBAF system was optimal. The gas consumption, separation factor and CH₄ recovery rate in CP system were boosted for adding TBAF. The average CH₄ recovery rate was up to 68.5%. The CP-TBAF combination provided a reference for improving the efficiency of coal mine gas hydration separation.

Mo₂C/Mo₃P heterojunction was successfully anchored on porous defect-rich carbon substrate by using ZIF-8 as substrate and introducing metal Mo in situ into its framework structure and undergoing a high-temperature calcination treatment. Mo₂C/Mo₃P@NC exhibited a large specific surface area and sufficient active sites, and more important, it induced the transition of Mo to the low-valence state (Mo ^δ+, 0<δ<4), and the enhanced localized charge sites Mo ^δ+ significantly increased the defects and active sites. Moreover, the bivalent Mo ^δ+-Mo⁶⁺ sites constructed a favorable pathway for CO₂ adsorption-desorption, and lithium-ion and electron migration, stabilized the two-electron product Li₂C₂O₄ and prevented the disproportionation to four-electron product Li₂CO₃ during CORR process. The excellent catalytic properties of Mo₂C/Mo₃P@NC drive the lithium-carbon dioxide batteries to follow the two-electron reaction pathway (2Li⁺+2CO₂+2e^-→Li₂C₂O₄), greatly reducing the charging potential and the battery polarization. Li-CO₂ battery assembled with Mo₂C/Mo₃P@NC cathode achieved a full discharge capacity up to 10538mAh/g, a reversible charge capacity of 10521mAh/g, and an improved coulombic efficiency of 99.8%; and the potential difference between charge and discharge at a current density of 100mA/g is only 0.7V, with a small potential gap in a 1100h cycle.

Under the goal of “dual carbon”, liquid hydrogen is rapidly penetrating from the aerospace field to the civilian sector. To accurately grasp the research dynamics and development trends in the field of liquid hydrogen in China, a bibliometric study was conducted using the literature visualization and analysis tool CiteSpace. With “liquid-hydrogen” as the research topic, a dataset of papers published by Chinese scholars from 1994 to 2023 was retrieved from the core databases of China National Knowledge Infrastructure (CNKI) and Web of Science (WoS). The study focused on conducting bibliometric and visualization analyses of the number of publications, research teams and institutions, research hotspots, and frontier analysis. The results reveals that the number of publications has increased rapidly since 2020, indicating a shift in liquid hydrogen research towards civilian applications, with a surge in research outputs. The annual number of English papers has gradually exceeded that of Chinese papers. High-yielding authors are clustered significantly, yet there is still considerable potential for collaboration among research institutions. Research hotspots exhibit significant migration and aggregation patterns, with liquid hydrogen propellants for on-orbit thermal management, efficient insulation technology for storage tanks, and hydrogen liquefaction technology as the main focuses in recent years. Additionally, the safety of liquid hydrogen is gaining increasing attention. Over the past 30 years, most research frontiers have been in the aerospace field, but since 2019, civilian sectors such as “hydrogen energy”, “hydrogen production”, “hydrogen liquefaction” and “hydrogen storage” have emerged as research frontiers in liquid hydrogen. This study’s findings have a positive impact on further promoting the vigorous development of liquid hydrogen research in China.

Diols (including ethylene glycol, propylene glycol, butanediol, et al.) are widely used in various fields, such as the chemical industry, medical treatment, biology, and agriculture, and the market demand is enormous. Currently, diols are mainly prepared from fossil resources, but there are limited reserves of fossil resources and environmental pollution in the process of use. Therefore, seeking a sustainable and green route for diols production has attracted significant attention. Biomass resources are the only renewable organic carbon resources in nature, and utilizing biomass-derived polyols for diols production is expected to overcome the shortage of fossil resources and achieve green and sustainable development. This review comprehensively summarizes the recent advances in the catalytic transformation of biomass-derived polyols (such as glycerol, erythritol, xylitol, and sorbitol) to diols. The catalytic types (exogenous hydrogenation and in-situ hydrogen source), catalytic efficiency, reaction solvents, reaction pathways, catalytic mechanisms, and catalyst stability for transforming polyols to diols are discussed in-depth. Based on the above discussion, future development for transforming biomass-derived polyols to diols is prospected, which could provide valuable references and theoretical guidance for researchers in this field.

Higher alcohols (HA) are important basic raw materials of energy and chemical industry. Higher alcohols synthesis via CO₂ hydrogenation (CO₂-HAS) possesses the characteristics of short process, high efficiency, and easy operation, which exhibits the great significance for both emission reduction and high value-added utilization of CO₂. Fe-based catalysts show great potential for industrial application due to their low cost and high activity, but they still faces some problems such as complex reaction network, difficult control of C—C bond formation and unsatisfactory yield of HA. Herein, the inherent limitation and suitable process conditions of CO₂-HAS were analyzed from the thermodynamic point of view, and the transformation path of HA and the evolution of Fe species were described. The effects of reaction conditions, promoters, preparation methods and supports on the performance of Fe-based catalysts were further discussed. The construction strategy of Fe-based multifunction catalytic reaction-coupling and its promoting mechanism were also revealed. The directed conversion of intermediate species and the precise regulation of C—C coupling are the key considerations in the design of Fe-based catalysts. 3D printing self-catalytic technology is expected to accelerate the large-scale preparation of Fe-based catalysts. Integration of various technologies may be one of the feasible ways for the industrial exploration of CO₂-HAS. The breakthrough of cheap green hydrogen production technology and its coupling with CO₂ capture technology will promote high quality development of CO₂-HAS and will be the mainstream trend in the future.

In order to improve the resistance of Ce-V-W/Ti catalysts to alkali (earth) metal poisoning, TiO₂ supports were prepared by sol-gel method and then modified by SiO₂ doping, and Ce-V-W/Ti-Si catalysts were prepared by impregnation method. The impregnation method was employed to simulate the poisoning effect on alkali species such as CaCO₃ and K₂O. The influence of SiO₂-modified support on the denitration activity and resistance against alkali metal poisoning of the catalyst was investigated. Characterization techniques including X-ray photoelectron spectroscopy, N₂ adsorption-desorption, H₂-temperature programmed reduction, and NH₃-temperature programmed desorption were employed to analyze the catalysts. Experimental results indicated that the SiO₂ modification of the Ce-V-W/Ti catalyst support reduced its denitration activity at low temperatures but significantly enhanced the catalyst's tolerance against alkali species. Overall, Ce₁V₁W₇/Ti-Si₄ exhibited the best resistance against alkali species, with the poisoning severity of various alkali species ranked as K₂O>Na₂O>CaCO₃>CaO>CaSO₄. The characterization results showed that SiO₂ modification weakened the activity of Ce oxide on the surface of the catalyst, but significantly increased the specific surface area and the number of acidic sites of the catalyst, and protected the reducibility of the active metal oxide during alkalosis.

The conversion of CO₂ into the high-value ethanol using renewable electrical energy is an important way to address the fuel storage challenge and reduce carbon emissions. The synthesis of Cu-based dual active site electrocatalysts to achieve catalytic CO₂ reduction to C₂ products is a research hotspot. Au nanoparticles were loaded on sea urchin-like CuO/Cu₂O to prepare Au _x -CuO/Cu₂O catalysts with different Au loads to improve the selectivity of electrocatalytic CO₂ reduction to ethanol. The reduction performance was evaluated in a flow cell with 1mol/L KOH as the electrolyte, and the total Faraday efficiency of the dicarbon products (C₂) reached 73.4% for Au₅-CuO/Cu₂O at a current density of 150mA/cm², with the ethanol Faraday efficiency reaching 40.0%, which was 4.2 times and 2.2 times higher than that of Au₂-CuO/Cu₂O and Au₈-CuO/Cu₂O, respectively, and the Faraday efficiency ratio of ethylene to ethanol was 1.35, which was 1.6 times and 3.46 times higher than that of the other two catalysts. The significant improvements of C₂ and ethanol selectivity by Au₅-CuO/Cu₂O were attributed to the suitable Au loading on the surface of CuO/Cu₂O, which realized an effective tandem catalytic process, i.e. The Au active sites promoted the generation of CO intermediates, and the Cu active sites accelerated the C—C coupling reaction of CO molecules to generate the C₂ product. This work could provide an important reference for the design and preparation of catalysts for electrocatalytic CO₂ reduction reaction with high ethanol selectivity.

Tetracycline residue in the environment will have chronic effects on aquatic organisms. Tetracycline is discharged into scenic water along with living water, affecting the water quality of scenic water. In this study, graphene-like (GBO) was prepared from orange peel powder as raw material and the electron transfer rate was increased by nitrogen doping optimization of GBO (NGBO). Using NGBO as solid state electron medium, Z-type ternary photocatalyst was constructed at g-C₃N₄/BIVO₄ interface. H₂O₂ oxide was introduced as oxidant on the basis of photocatalysis and the Z catalyst/photo-Fenton catalyst system was established. The photocatalytic degradation of TC over Z-type catalyst was studied by adding 10mg catalyst and 5mmol/L H₂O₂ into 50mL of 10mg/L tetracycline solution. The results indicated that the CN/NGBO/BV composite had the strongest photo-Fenton-like catalytic degradation ability of TC. Catalytic degradation of TC was enhanced as light and H₂O₂ contribute to the formation of more ·OH and ·O₂^- during catalytic degradation of TC systems, while experimental results showed synergy between photocatalysis and fenton-like catalysis.

Water electrolysis has been regarded as the most promising green hydrogen production technology. The development of highly efficient hydrogen evolution reaction (HER) catalysts is of great significance for its large-scale application. In this study, a series of NiS(x)@NF transition metal sulfide nanosheet catalysts (x represents the amount of thiourea) were prepared by in-situ growth of Ni₃S₄ on nickel foam (NF) with thiourea as sulfur source. The structure, morphology and metal valence of the catalysts were characterized. The HER properties of the catalyst were studied in 1mol/L KOH electrolyte and simulated seawater respectively. The catalyst preparation was by a simple hydrothermal method and directly used the Ni on NF without adding Ni. The method was simple and low-cost, and the active phase of the catalyst was firmly attached onto the NF substrate presenting high stability. Compared with unvulcanized NF, the NiS(x)@NF catalysts presented a significantly improved HER performance in alkaline electrolytes. This could be attributed to the in-situ growth of Ni₃S₄ nanosheets on NF. Among them, the NiS(0.14)@NF catalyst possessed the smallest overpotential (η₁₀=0.091V, η₁₀₀=0.102V) and the highest intrinsic catalytic activity with a Tafel slope of only 105.23mV/dec. The HER activity of the catalyst significantly decreased in the simulated seawater, indicating that the interfering components in the seawater had a significant impact on HER activity. However, it was worth noting that the NiS(0.14)@NF catalyst exhibited high stability in both alkaline solution and simulated seawater under different current loads (10mA/cm², 40mA/cm², and 100mA/cm²). This could also be ascribed to the in-situ growth of Ni₃S₄ nanosheets on NF, which made the active phase NiS(x) firmly attach onto the NF substrate.

Carbon dots hybrid hydrogel is a gel material with comprehensive properties of each component based on carbon dots and auxiliary materials. Inserting carbon dots into hydrogels can not only solve the fluorescence quenching effect caused by their aggregation, but also improve the performance of hydrogels and give them more abundant characteristics. At present, there is no detailed review of the structural characteristics of carbon dots, the performance enhancement mechanism, application fields and existing problems of carbon dots hybrid hydrogels. Therefore, this paper introduced the structural characteristics of carbon dots and common surface modification technologies, briefly described the preparation methods of carbon dots hybrid hydrogels, focused on the analysis of the performance enhancement mechanism of carbon dots on hydrogels, comprehensively summarized the applications of carbon dots hybrid hydrogels in wastewater treatment, bionic intelligent devices and other fields, and put forward the research trends of their applications in different fields. It was pointed out that in the face of broad space for composite hydrogel material design, the new material development strategy of computational simulation and theoretical prediction, followed by experimental verification, should be preferred to further enhance the application value of carbon dots hybrid hydrogel.

In view of the potential risk of runaway reaction heat in the engineering application of current polyurethane grouting materials for mining, it is of great practical significance to explore innovative and efficient polyurethane material modification technology. In this work, the causes of runaway reaction heat of polyurethane grouting materials were analyzed with a focus on the intrinsic performance defects of polyurethane materials, such as high exothermic heat, strong heat storage and poor flame retardancy, which were mainly explained as the internal causes of the runaway reaction heat, and the external causes such as environment, system and personnel were also introduced. Focusing on the internal causes of runaway reaction heat, the research progresses of polyurethane modification both domestically and internationally in recent years were reviewed from the perspective of the control of reaction heat release and heat storage temperature as well as the modification of flame-retardant property. Finally, in terms of the innovation of polyurethane material modification methods and the management of product safety access systems combining with the existing technical problems in material modification research, the reasonable outlooks were made on deepening the safety and green environmental protection application of polyurethane grouting materials in mines.

Due to the toxicity and corrosiveness of sulfides in industrial raw materials, which can adversely affect industrial production and ecological health, it is of great significance to use optimal desulfurization technology to achieve deep removal of sulfides. This paper took the adsorptive removal of complex organic sulfides as the research scope. Firstly, it described the advantages of adsorption desulfurization and the physical and chemical adsorption processes involved. Subsequently, it took zeolites with abundant pore structure and large specific surface area as the research object, and reviewed the application status of the microporous (FAU, MFI, Beta), mesoporous (MCM-41, SBA-15, KIT-6, MCM-48) and hierarchical zeolites in the adsorptive removal of organic sulfides in accordance with their different pore sizes. The factors affecting the desulfurization performance of zeolites, including the type, content and dispersion of active components, the micromorphology, pore structure and acid sites of zeolites were further analyzed. The analysis indicated that the desulfurization performance of zeolite desulfurizers was closely related to the microstructure of zeolite supports and the surface property. Through precise design and controlled synthesis to obtain the desulfurizers with large sulfur capacity, high desulfurization accuracy, high selectivity, stable pore structure, long service life, renewable use and other excellent qualities would be the important direction of future research.

Titanium dioxide (TiO₂) is a kind of typical semiconductor material and widely used in photocatalysis, however, its wide energy band gap limits its practical application. Black TiO₂ (B-TiO₂) nanomaterials can effectively improve their visible light-response performance and quantum efficiency through constructing structural defects on TiO₂ surface to reduce the band gap, which has attracted great attention. This paper introduced the basic properties of B-TiO₂ such as optical property, crystal types, defects and microstructures, and systematically summarized the methods of preparation and defect construction of black TiO₂ in recent years, including calcination, sol-gel and chemical reduction etc. It was also summarized the improvement strategy of performance for black TiO₂ and its application in water purification, medical treatment, energy conversion and other fields. Finally, the future research of B-TiO₂ needed to focus on the following aspects. The building of structure-activity relationship in depth from theory and experiment was basic for reasonable design of surface defects and development of efficient synthesis methods for B-TiO₂, which called for more advanced characterization and analysis tools. Besides, it was an important prerequisite to further enhance the structural stability of B-TiO₂ with high activity for practical application. The development of interdisciplinary disciplines should promote the applications of B-TiO₂ to various fields.

For the removal of radioactive elements by traditional adsorbents, there are shortcomings such as long adsorption time and unsatisfactory adsorption effect. The new porous adsorbent materials such as covalent organic frameworks (COF), metal-organic frameworks (MOF) and conjugated microporous polymers (CMP) have higher separation efficiencies for radionuclide separation due to the excellent physicochemical properties, high specific surface area, high porosity, fast charge-carrier mobility and tunable functionality. This paper focused on the removal of radioactive elements by various new porous adsorption materials, such as covalent organic frameworks (COF), metal organic frameworks (MOF) and highly crosslinked polymers (HCP) by summarizing the latest research progress on the use of new porous adsorption materials for the adsorption and separation of radioactive nuclides. The design and preparation of new porous adsorption materials, the removal performance of radioactive elements and the removal mechanism of radioactive elements were emphasized. Finally, based on the above analysis, the current problems of new porous adsorbent materials for radionuclide adsorption and separation, such as the difficulty of dealing with new porous adsorbent materials in powder form and the problem of structural instability under extreme chemical conditions, were proposed. The future directions of the research were also envisioned, such as expanding the research from purely basic research to more practical aspects and vigorously development of effective synthesis methods to obtain products with high yields and no by-products.

The development of formation pores, micro-fractures and fractures leads to frequent collapse of the wellbore, which seriously hinders safe and efficient drilling. The maturity of the plugging theory is an important guarantee for the development of high-performance plugging agents. Efficient plugging of pores, micro-cracks and fractures through plugging agents is the key to stabilizing the borehole. In this paper, the research status of different plugging theories (rigid plugging theory, flexible plugging theory, film-forming plugging theory) and various plugging materials (asphalt, polymeric alcohols, silicates, nanomaterials) was reviewed. The shortcomings of the existing plugging theories and plugging materials were pointed out. The current plugging theories and the difficulties faced by the research and development of plugging materials were summarized. It was proposed that the size distribution law of reservoir pore throat and reservoir morphology and structure should be studied in depth through the numerical simulations. The development trend of high-efficiency plugging materials was carried out in the aspects of dendritic polymers, rigid shell and flexible core composites, biomass-based nanomaterials modified asphalt, and nanomaterial dispersion stability.

In this work, nitrogen doped carbon nanofibers (NCNF) were prepared by electrospinning and high-temperature carbonization treatment, and nickel cobalt layered double hydroxide (NiCo-LDH) nanosheets were in-situ grown on the surface of NCNF through two step solvothermal reaction to produce NCNF/NiCo-LDH/NiCo-LDH composite electrode. The morphology and structure of composite electrode were observed and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and raman spectroscopy (Raman). Cyclic voltammetry (CV), constant current charge and discharge (GCD) and AC impedance (EIS) were used to investigate the electrochemical properties of composite electrode. As a result, the nanosheet array composed of large and small sheet could be formed on NCNF, the loading of active substances could be increased effectively, the agglomeration of NiCo-LDH could be inhibited, and the dispersion and electrochemical active area of NiCo-LDH on NCNF could be enhanced through the two-step solvothermal reaction. The NCNF/NiCo-LDH/NiCo-LDH composite electrode demonstrated the superior electrochemical properties. The specific capacitance can reach 2898.7F/g at 1A/g, the capacitance retention rate was 78.4% at 10A/g, and after 6000 charge-discharge cycles, the capacitance retention was as high as 92.3%. An asymmetric supercapacitor (ASC) assembled using NCNF/NiCo-LDH/NiCo-LDH and activated carbon (AC) had a high energy density of up to 69.1W·h/kg with a power density of 743.6W/kg, and the capacitance retention was 93.4% after 6000 charge-discharge cycles at 10A/g. Therefore, the NCNF/NiCo-LDH/NiCo-LDH composite could be as promising electrode material for supercapacitor.

In this paper, a binary eutectic mixture of lauric acid-paraffin (LA-PS) was prepared from lauric acid (LA) and paraffin (PS), and the binary eutectic mixture was adsorbed into nano-SiO₂ aerogel by vacuum adsorption method to form a composite phase change material lauric acid-paraffin/nano-SiO₂ aerogel. Leakage experiments showed that the maximum adsorption rate of the nano-SiO₂ aerogel to LA-PS was 70%. The results of Fourier infrared spectroscopy that the LA-PS/nano-SiO₂ aerogel had excellent chemical compatibility. The results of the DSC test showed that the phase transition temperature of the LA-PS/nano-SiO₂ aerogel was 35.19℃ and the latent heat of the phase transition was 115.89J/g. In addition, the LA-PS/nanosized SiO₂ aerogel had an energy storage efficiency of 98.99%, indicating that LA-PS/nanosized SiO₂ aerogel had good thermal storage properties. Therefore, the prepared composite phase change materials had suitable phase change temperature, high latent heat of phase change and good thermal stability and durability for the utilization of transparent enclosure for glass windows, and thus having a good application prospect.

The polyamic acid (PAA) was synthesized by pyromellitic dianhydride (PMDA) and 4,4'-diaminodiphenyl ether (ODA), followed by polymerization with a polyurethane prepolymer constructed by isophorone diisocyanate (IPDI), polytetramethylene tetramethylene ether glycol (PTMG) and 1,4'-butanediol (BDO) to prepare a block copolymer poly(amide-urethane) (PAA-PU). Subsequently, the PAA-PU evolved to final poly(imide-urethane) (PI-PU) by thermal imidization by a plate vulcanizer. The chemical structure and performance of aforementioned copolymers were characterized by infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), mechanical property testing, dynamic thermomechanical analysis (DMA), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). As a result, the tensile strength was enhanced to 63.7MPa for PAA-PU and 86.4MPa for PI-PU, compared to 28.3MPa for polyurethane (PU). Besides, the temperature of maximum degradation rate of copolymer reached to 352.6℃ and the residual retention was increased. In addition, the glass transformation temperature of copolymer was improved from 37.2℃ to 91.6℃ as polyimide segments incorporated and further elevated to 128.5℃ due to additional content of polyimide segments. Meanwhile, the increases of storage modulus, reduction of loss modulus and widened rubber platform of PI-PU copolymer were also displayed in respect to PU.

Mixed matrix membranes (MMMs) serve as an effective strategy to enhance the separation performance of polymeric membranes with zeolitic imidazolate frameworks (ZIFs) materials being considered as ideal filler particles. In pursuit of high-performance pervaporation membranes, this study aimed to fabricate MMMs by incorporating ZIFs particles into the poly-dimethyldiethoxysilane (PDMDES) polymer. Initially, ZIF-8, ZIF-90 and ZIF-8-90 particles were synthesized and their successful synthesis was confirmed by FTIR characterization. These ZIFs particles were then incorporated into the PDMDES polymer to create three distinct ZIFs/PDMDES MMMs. The morphologies, surface hydrophobic properties and pervaporation performance of these MMMs were investigated. The incorporation of ZIFs particles not only increased the membrane thickness but also significantly enhanced surface hydrophobicity, leading to marked improvements in pervaporation performance, as compared to the pure PDMDES membrane. Among these, the ZIF-8-90/PDMDES MMM demonstrated the best overall performance. Specifically, in the separation of a 5% (mass) ethanol aqueous solution at 60℃, it achieved outstanding separation performance, yielding a permeation flux of 8651.7g/(m²∙h) and a separation factor of 8.87.

Magnetorheological media in service are subjected to multi-field coupling of temperature rise, magnetic field and sustained shear, whose action induces an unknown and difficult to accurately predict rheological behavior. Due to the problem that back propagation (BP) neural networks tended to converge to local extremes, the prediction model of the rheological properties of magnetorheological grease with high-temperature thermal effect was optimized by establishing the sparrow search algorithm (SSA) optimized BP neural network, which was used for the characterization and prediction of the relationship between experimental temperatures, magnetic fields, thermal effect time, shear rate and the rheological properties of magnetorheological grease. The results showed that at high magnetic fields, the large aggregation of magnetic chains was less impeded by the soap fibers and the magnetorheological grease shear stress increased substantially. The high-temperature thermal effect caused some damage to the magnetorheological grease composite structure, as evidenced by the overall lower shear rate profile of MRG-24h under all experimental conditions. The BP prediction model indicated low generalization performance with negative R² when evaluating data with large local discretization, whereas the SSA-BP prediction model still had high prediction accuracy when evaluating the prediction performance for overall different datasets and data with small and large local discretization. The SSA-BP prediction model can provide a prediction of the rheological properties of magnetorheological grease and data support for the design and development of magnetorheological devices.

Graphene oxide (GO) was modified with L-glutamic acid (L-Glu) to improve the dispersibility of GO, and the modified graphene oxide (L-GO) was used as a filler doped into epoxy resin (EP) to prepare L-GO/EP coating. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze the morphology and surface properties of GO before and after the modification. The hardness and adhesion of the coatings were identified, and the physical properties of the coatings were evaluated. The thermal stability and anticorrosion properties of L-GO/EP were investigated by using thermogravimetric analyzer (TG), electrochemical alternating impedance (EIS) and polarization curve (Tafel). The results showed that compared with GO, the modified L-GO nanosheet layer spacing increased by 0.115nm, the I_D/I_G value increased from 0.98 to 1.01 and L-GO had a higher level of disorder. L-Glu attached to the surface of GO, which increased the dispersion of GO in the epoxy resin. The agglomeration problem of GO was solved and the stability of the coating was improved. Compared with EP and GO/EP coatings, L-GO/EP coating offered the highest hardness (5 H), abrasion resistance (0.9L/μm), flexibility (3mm), impact strength (50cm) and adhesion (Class 1). Compared with EP, the corrosion current density of L-GO/EP coating decreased from 2.85×10^-6A/cm² to 7.65×10^-8A/cm² and the polarization resistance increased from 2.06×10⁴Ω·cm² to 5.79×10⁵Ω·cm², respectively. The improvement of anticorrosive properties of L-GO/EP coating were closely related to the increase of dispersion and physical barrier properties of L-GO.

Inspissated oil is usually exploited under high temperature and high pressure condition, and the resulted effluent emulsion is considered as an oil-in-water type, which is hard to be demulsified using traditional demulsifiers. In this study, CuFe₂O₄ magnetic nano-demulsifier prepared by chemical coprecipitation method were combined with multi-wall carbon nanotubes (MWCNT) to prepare a new type of reusable magnetic nano-heavy oil demulsifier (WD-03), whose properties were furthermore studied. The demulsification test showed that WD-03 exhibited a nearly 0° contact angle with water, demonstrating high hydrophilicity. The demulsification could reach the optimal effect with the dosage of WD-03 of 2g/L and the reaction time for 30 minutes. The influence of pH and temperature (20—80℃) on demulsification was not remarkable. For the emulsion with the oil content of 2000mg/L and the moisture content of 90%—98% produced in Xinjiang Karamay Oilfield, the moisture content in the upper inspissated oil decreased to less than 5% and the petroleum hydrocarbons in the lower oily wastewater were less than 5mg/L after WD-03 demulsification treatment for inspissated oil. The moisture content of the upper heavy oil was less than 10% and the oily wastewater in the lower layer was less than 50mg/L after the magnetic nano-demulsifier being reused for 3 times. The demulsification rate for oil-in-water inspissated oil emulsion could still reach 95% after 5 times recycling and reusing, indicating that WD-03 can be recycled and reused. WD-03 was characterized by modern analytical methods such as scanning electron microscopy, X-ray diffraction, infrared spectroscopy, etc. The demulsification mechanism of WD-03 for oil-in-water heavy oil emulsions was speculated. The highly hydrophilic WD-03 tended to react with the asphalt and resin π-bonds in oil due to the extensive π-bond system formed on the surface of carbon nanotube material MWCNT. The polymerization of oil droplets and the separation from water was promoted. It was easily separated from water under the condition of an external magnetic field due to the magnetic material properties of WD-03, which indicated high recycling efficiency. At the same time, WD-03 also exhibited strong adsorption properties, which could absorb tiny emulsion oil particles and aggregate into large oil droplets. This study had extremely high theoretical and market development value for efficient demulsification during exploiting inspissated oil mining in China.

Human industrial activities cause the gradual increase of CO₂ content in the atmosphere, forming the greenhouse effect and leading to global climate anomalies. Carbon capture, utilization and storage (CCUS) technology, especially CO₂ chemical absorption process, is one of the most effective ways to achieve large-scale CO₂ emission reduction and curb global climate change. However, due to the high energy consumption and high cost of CO₂ capture technology, CCUS technology cannot be promoted and commercialized on a large scale. In recent years, catalytic absorbent regeneration, as a new class of technology for low temperature energy-efficient CO₂ desorption with great potential for large-scale application, has attracted extensive attention from researchers. This review focused on the recent research progresses and developments of the catalyst-assisted solvent regeneration technology. The characteristics and performance of heterogeneous catalysts was discussed in detail and the advantages, disadvantages and challenge of various catalysts were identified and commented upon. The enhancement mechanism of catalytic CO₂ desorption and the role of Lewis acids, Brønsted acids and basic active sites were summarized. The main factors that affected the desorption and regeneration performances of heterogeneous catalysts were also addressed. Finally, the status of catalytic solvent regeneration for post-combustion CO₂ capture was comprehensively analyzed and the future development direction and prospect of catalyst-aided solvent regeneration technology were also proposed.

The biological nutrients removal (BNR) process is inevitably affected by salinity changes. Understanding how bacteria adapt to high-salinity environments and regulating the operation mode of the system are crucial essential to maintain the stability of the system economically and efficiently. This study summarizes current research findings, demonstrating that salt-tolerant microorganisms are capable of quickly exchanging water, small molecules of amino acids, glycerol, polysaccharides and inorganic substances such as potassium and sodium ions with the environment to coordinate osmotic pressure with the change of environmental salinity. Extremophilic bacteria have developed unique cellular structures that take advantage of various types of energy sources, including light, electricity, and electron donors with lower chemical potentials than fatty acids, to achieve the energy-enriched-biopolymers accumulation (e.g. polysaccharides, polyphosphates, polyhydroxyalkanoates and polysulfides). Employing alternating anaerobic/anoxic/aerobic biofilm processes, along with cyclic accumulation and uptake of various energetic substances, introducing saline-adapted biomass, and feeding the reactor with seawater to acclimate biofilm communities, can enhance the efficiency of simultaneous nitrification and denitrification (phosphorus removal) in hypersaline environments. Finally, the study points out that how to configure a reasonable process with good stability, and to enhance microorganisms salt tolerance by appropriate external energy amendments are of urgent importance in the future research as well as in the BNR engineering practices.

Pharmaceutical process residues (PPRs) are the byproducts from pharmaceutical industry that is popular and developed rapidly nowadays, involving two typical categories: Chinese herb residues (CHRs) and antibiotic fermentation residues (AFRs). Due to the dual attributes of renewable resource and hazardous waste of PPRs, to realize their safe and value-added utilization is of great significance to the society, the industry and the enterprise for environment protection and resource saving. In this study, focusing on the most accessible thermo-chemical conversion strategies, the research progress on the characteristics and influential factors, the evolution mechanisms of elements or components, and the properties of PPR-derived biofuels (solid, liquid and gas) are reviewed. Results demonstrate that the defective components (high moisture, rich nitrogen and abundant oxygen) are big obstacles to the conversion of PPRs into desirable biofuels, impeding their clean and efficient thermal utilization. On one hand, some pretreatments like dehydration and torrefaction can acquire enhanced performance of solid biofuels by the capabilities of upgrading and denitrogenating PPRs focusing on the evolution regulation of moisture, carbon and nitrogen fractions, while the enhancement effect is still limited together with the proper disposal of secondary byproducts. On the other hand, thermo-chemical conversion (pyrolysis, gasification or hydrothermal liquefaction) strategies on PPRs can produce favorable gaseous or liquid biofuels with higher energy density, nevertheless, the quality or the yield of resultant biofuels (pyrolytic gas, gasified gas, biogas and bio-oil) would be all inhibited in varying degrees due to the evolution and conversion of unfavorable/useless components (such as nitrogen, oxygen and ash) in PPRs. To fulfill stringent emission standards and high-efficient thermal utilization, more efforts should be made to develop satisfying strategies on the valorization of PPRs into biofuels in a more eco-friendly and profitable way. Furthermore, by comparing the properties and uses of various PPR-derived biofuels, hydrothermal integrated with subsequent thermo-chemical approaches seems to be a preferred option when focusing on the clean and efficient valorization of PPRs.

The chemical absorption method using organic amine as absorbent has the advantages of large absorption capacity, fast absorption rate, high CO₂ capture efficiency, etc., but its higher regeneration thermal energy consumption and other problems seriously affect its development. The traditional thermal desorption regeneration faces problems such as low energy utilization, ammonia escape, oxidative degradation of absorber, etc. It is necessary to improve and optimize the current research on organic amine-rich liquid desorption and regeneration process in order to reduce energy consumption and loss. This paper introduced the catalytic desorption and regeneration and membrane desorption and regeneration processes based on thermal desorption, and summarized the basic principles and current research status of the emerging microwave desorption and regeneration, mineralization regeneration and electrochemistry-mediated amine desorption and regeneration processes, and compared and analyzed the advantages and disadvantages of the various processes and the types of organic amines to which they were applicable. The selection of suitable organic amine rich liquid desorption process was conducive to reducing the energy consumption of desorption. The catalytic desorption was suitable for most organic amine absorbents, the membrane desorption was suitable for monoamine absorbents, the microwave desorption and regeneration was suitable for organic amines with more polar groups and large dielectric constants, while the mineralization regeneration was suitable for tertiary amine absorbents, and electrochemically-mediated amine desorption and regeneration was suitable for polyamine absorbents.

Reductive materials hold significant applicative value in the halogenated solvents contaminated groundwater remediation, yet their practical application faces hurdles such as limited migration, low efficacy, and high costs. This review summarizes the current status of halogenated solvent contaminations and advancements in research on reductive remediation materials, as well as their applications in the remediation of halogenated solvent pollution. Describing the potential and challenges these materials pose in terms of improving repair efficiency and cost reduction, this review aims to scrutinize the pros and cons of existing technologies and simultaneously explore possible directions for future advancements. To further enhance the efficacy of halogenated solvent pollution remediation, there should be a deeper investigation into modified reductive agents to augment their reactivity and migration capabilities. Additionally, there is a need to strengthen coupling studies between material technologies and optimize construction processes to reduce remediation costs and improve the feasibility of engineering implementation. Moreover, attention must be directed towards the environmental impact during the remediation process to ensure the green and sustainable development of the technology. Through these comprehensive measures, it is anticipated that halogenated solvent pollution remediation technology will progress toward a more efficient and environmentally friendly phase.

Adsorbent injection demercuration is an independent mercury removal technology besides the synergistic removal of mercury by existing equipment. This paper mainly reviewed the problems and advantages of two kinds of adsorbents of activated carbon and magnetic metals in the actual application, compared the characteristics and performance of the two types of materials, elaborated the difference on the injection position and concluded the recovery of elemental mercury and the disposal of mercury compounds. The development of theoretical and experimental research on mercury removal on activated carbon-based adsorbents and the stability analysis of mercury compounds were highlighted, meanwhile, the development on magnetic metal-based adsorbents, their practical applications and the process and operation parameters of mercury recovery by magnetic separation were described in detail. The discussion indicated that the sulfur and selenide-based adsorbents were very promising adsorbents with superior ability, high stability and low leachability on mercury compounds. Finally, an outlook on the problems and prospects for the application of individual mercury removal technologies was presented.

The excessive accumulation of excavated waste in landfills can lead to environmental pollution of the surrounding soil, groundwater, and air. Due to the similarity in composition between excavated waste and municipal solid waste, co-gasification is an efficient method for the clean disposal of excavated waste. The product distribution and syngas component characteristics of the co-gasification process were explored under different gasification temperatures and blending ratios, and the synergistic effect of co-gasification was analyzed. Through gasification evaluation index calculation and response surface simulation, the blending ratios and gasification temperatures were optimized. The results indicated that increasing the gasification temperature promoted the decomposition of solid residue into gas and improved gas production rates. Experimental values of the solid residue of the blends at a gasification temperature range of 700—1000℃ were lower than the linear additive values of the gasification of a single raw material, demonstrating a positive synergistic effect on promoting the transformation of solid coke through the co-gasification of blends. The high content of H₂ and CH₄ in syngas suggested that excavated waste had positive gasification characteristics. Experimental yields for each component in syngas were higher than calculated values at 900℃ and 1000℃, indicating that higher gasification temperatures promoted syngas generation. The gasification evaluation index as well as carbon conversion rate significantly increased with the increase of blending ratio of excavated waste and gasification temperature. Under the gasification temperature of 1000℃, the calorific value and gasification efficiency of syngas reached the maximum value when the blending ratio of excavated waste was 60% and 80%, respectively. The maximum H₂ (188.44mL/g) and CH₄ (104.22mL/g) yields were obtained for single gasification of excavated waste at 1000℃, but CO yields also reached the maximum value within this condition. When the blending ratio of excavated waste was in the range of 60%—89% and the gasification temperature was close to 1000℃, the content of H₂ and CH₄ in syngas product of blends was higher, and meanwhile higher calorific value, carbon conversion rate and gasification efficiency of syngas could be obtained. This study provides the basis for the research and application of the co-gasification technology of excavated waste and municipal solid waste.

Vanadium slag, derived from converter vanadium slag, contains a large amount of iron, and its secondary utilization has significant economic value and practical significance. In this paper, H₂SO₄ was used as the acid leaching solution, and the response surface method was used to optimize the acid leaching process parameters. Subsequently, the α-Fe₂O₃/Bi₂WO₆ composite photocatalyst was successfully prepared by the calcination-hydrothermal method for the photodegradation of methyl orange (MO), a dye wastewater, under simulated visible light. The results showed that the optimal process parameters for acid leaching were as follows: H₂SO₄ concentration of 2.8mol/L, acid leaching temperature of 98℃, acid leaching time of 138min and solid-liquid ratio of 1∶4.2. Under these optimal parameters, the iron leaching efficiency from vanadium slag was 71.0%. After preparing α-Fe₂O₃ from vanadium slag using a precipitation-calcination method, the photodegradation performance of the VS-Fe₂O₃/Bi₂WO₆ composite synthesized via hydrothermal treatment was found to be significantly superior to that of the commercial Fe₂O₃/Bi₂WO_6. The optimal doping amount of VS-Fe₂O₃ was 10%. When the H₂O₂ dosage was 19.58mmol/L, pH was 6.5, catalyst dosage was 0.4g/L, initial concentration of wastewater was 10mg/L and photoreaction was carried out for 6h, the removal rate of MO was 96% and the COD removal rate was 88.4%. The effluent COD concentration of 13.34mg/L met the requirements of the “Integrated Wastewater Emission Standard” level A standard and the rate constant ofthe photoreaction was 4.8 times that of the pure Bi₂WO₆ phase. The degradation mechanism of MO was primarily due to the photo-Fenton reaction under the action of H₂O₂ synergistic VS-Fe₂O₃/Bi₂WO₆. This paper can provide a reference for the efficient and clean resource utilization of vanadium slag and its resource utilization in photocatalysis.

Hydrogen sulfide removal by catalytic oxidative method with chelated iron has the advantages of high efficiency, simple operation, and recyclable sulfur resources. At the same time, there are also problems such as slow regeneration of desulfurization liquid, ligand degradation, and difficult separation of sulfur products. In this study, ethylene diamine tetraacetic acid (EDTA) was used as the organic ligand to complex Fe³⁺ for the absorption and oxidation of hydrogen sulfide while oxygen was used in the regeneration of ferrous ion to ferric ion. The effects of different factors on the desulfurization were investigated and the system was optimized. The results showed that the system achieved a maximum hydrogen sulfide removal efficiency of 99.99% when the Fe(Ⅲ) was 0.09mol/L and the molar ratio of EDTA to Fe(Ⅲ) ([L ^n-]/[Fe³⁺]) was 1.4 at pH=9. X-ray diffraction, X-ray photoelectron spectroscopy and energy dispersive spectroscopy detection confirmed that the solid product was mainly elemental sulfur. The scanning electron microscope and particle size analysis exhibited that the PEG600 was beneficial to particle growth and agglomeration, causing the size distribution increasing from 10—100nm to 100—1000nm. Meanwhile, the addition of PEG600 improved the production of elemental sulfur over 90%. PEG600 also reduced the degradation efficiency of EDTA which was less than 10% after six cycling experiments. Ni(Ⅱ) in the desulfurization solution facilitated the regeneration of Fe(Ⅲ). The regeneration time was shortened from 60min to 20min when the molar concentration of Ni(Ⅱ) was 5% of Fe(Ⅲ) which promoted the oxygen utilization.

Coal gasification fine slag (FS) and aluminum ash (AA), being industrial wastes, were used as raw materials to prepare the mesoporous adsorbents by one-step alkali fusion treatment. The adsorption performance of the above mesoporous materials on methylene blue in water was investigated. The results showed that the optimal treatment conditions for FS were m_FS∶m_NaOH=5∶10, calcination temperature of 450℃ and treatment time of 5h. The optimal treatment conditions for AA were m_AA∶m_NaOH=5∶8, calcination temperature of 550℃ and treatment time of 3h. The adsorption capacity for methylene blue increased from 1.16mg/g (FS-0) to 67.85mg/g (FS-2), an increase of nearly 58 times. The adsorption capacity for methylene blue increased from 1.4mg/g (AA-0) to 23.95mg/g (AA-2), an increase of nearly 17 times. The characterizations of X-ray diffraction, Scanning electron microscope, BET and Fourier transform infrared spectrometer indicated that the formation of mesoporous structure, Si—O— groups with oxygen defect sites and a large number of Al—OH and Si—OH bonds was responsible for the greatly improved adsorption performance of theadsorbents. This study indicated that FS and AA could be used as cheap adsorbents for methylene blue in water, which provided a potential method for their resource utilization and treatment of dyeing wastewater.

A cathode material was prepared by coating, compaction and calcination using nickel foam as a carrier, acetylene black powder, and nano Fe₃O₄ as a catalyst. This material is capable of achieving in-situ generation of H₂O₂ and activation of H₂O₂ to generate hydroxyl radicals (·OH) in the presence of Fe(Ⅱ). X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterise the lattice and morphological structures of the samples. The cathode materials prepared were applied to the electro-Fenton system to treat simulated wastewater containing 2,4,6-trichlorophenol, and the electrocatalytic performance of acetylene black/Fe₃O₄ materials was investigated. Under the optimal experimental conditions of a Fe₃O₄/C ratio of 3∶7, a current intensity of 50mA and an initial pH of 3 in the electro-Fenton system, the removal rate of 2,4,6-trichlorophenol was 70.8% after 120min of electrolysis. The acetylene black/Fe₃O₄ electrodes effectively broadened the pH range (3—11) of the electro-Fenton system. The polyhedral structure of Fe₃O₄ was embedded in the surface of acetylene black, providing a material foundation for the in-situ generation and activation of H₂O₂.

Using residual sludge as raw material, original biochar (BC), ball-milled sludge biochar (FBC), phosphomolybdic acid-modified biochar (PBC), and phosphomolybdic acid-Fe₃O₄ ball-milled co-modified biochar (PFBC) were prepared at a pyrolysis temperature of 200℃ through phosphomolybdic acid (PMA) modification and ball milling method for Fe₃O₄ loading. These adsorbents were employed for the adsorption of tetracycline (TC) from water. The results demonstrated that PFBC exhibited a larger specific surface area and pore volume, and smaller particle size. The co-modification can significantly enhance the surface oxygen functional groups. The spectra of XRD and XPS both indicated that PFBC was successfully loaded with Fe₃O₄. The PFBC achieved a TC removal efficiency of up to 88.7% under optimum conditions with an initial TC concentration of 30mg/L, a PFBC dosage of 0.25g/L, and a pH of 7. The adsorption of TC onto PFBC fitted well with the Langmuir adsorption isotherm and pseudo-second-order kinetic models, which indicated that the adsorption process was a mono molecular layer chemisorption. The saturation adsorption capacity reached 500.0mg/g at 25℃. Even after five recycle run, a removal efficiency of over 63.3% for TC could still be achieved by PFBC from the solution. Its saturation magnetization intensity reached 18.1emu/g, allowing for effective recovery by means of a magnetic apparatus. The mechanisms involved in TC adsorption onto PFBC include pore filling, π-π interactions, electrostatic attraction, and chelation. In conclusion, this study provides a new strategy for the application of modified sludge biochar in antibiotic wastewater treatment.

CoW-LDH/ATP composites with notable micro- and nanocluster sheet structures were created by employing a one-step hydrothermal process to fix the sheet CoW-LDH on the attapulgite (ATP) rod-shape structure. The microscopic morphology and the physical phases composition were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). A systematic study was conducted to explore the adsorption properties and the mechanism of Pb²⁺ adsorption in lead-containing wastewater under laboratory conditions. The experimental results of Pb²⁺ adsorption treatment in wastewater showed that at the initial Pb²⁺ concentration of 5.0mg/L and solution pH of 6, the Pb²⁺ removal efficiency reached approximately 99% after 20min adsorption. The Pb²⁺ adsorption selectivity of CoW-LDH/ATP composites was significant, with a partition coefficient K_d value of 938.51L/g, and nearly no interference from coexisting anions. CoW-LDH/ATP composite had a saturation adsorption capacity for Pb²⁺ of 872.07mg/g, which was significantly greater than the concave clay-based materials that had been described in the literature. Furthermore, following eight cycles of adsorption-desorption, the Pb²⁺ removal efficiency held steady at over 94%, suggesting the CoW-LDH/ATP composites had strong cyclic stability. The study on the adsorption mechanism of Pb²⁺ showed that the removal of Pb²⁺ by CoW-LDH/ATP composites was predominantly through the metal-oxygen bonding complexation and ligand retention between oxygen-containing groups and Pb²⁺. The prepared CoW-LDH/ATP composites had the advantages of quick adsorption rate, high adsorption capacity and strong selectivity. The results of this work might offer a theoretical foundation and technical assistance for the extensive treatment of Pb²⁺ contamination wastewater.

The review summarizes the National Natural Science Foundation of China (NSFC)’s fund applications, grants and success rates, regarding the discipline of chemical engineering & industrial chemistry (B08) in 2024. Fund applications and grants under the 16 secondary application codes/sub-directions of B08 were outlined, and statistics for typical funded programs were specified, so as to provide suggestions for proposal applications in the next year.