最新刊期
卷 50 ， 期 1 ， 2025
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摘要：In heterogeneous catalytic reactions, the size effect of metal catalysts has a significant impact on their catalytic activity, product selectivity and stability. Reducing the size of metal catalysts from nanoparticles to sub-nanoclusters, or even to atomic-scale, can effectively increase the utilization of active sites, thereby greatly enhancing catalytic activity. Cobalt (Co)-based catalysts have attracted attention in many reactions due to their unique electronic structure and excellent catalytic activity. Based on the current research status of Co-based catalysts, the structures and characteristics of Co-based catalysts of different sizes (nanoparticles, clusters, single atoms, and diatomic species) were introduced. Strategies for improving the stability of Co-based catalysts with different sizes, including spatial confinement, metal-support interactions, and metal-metal interactions were elaborated. The impacts of these strategies on the performance of different catalytic reactions, as well as their advantages and disadvantages, were analyzed. Prospects for future research on Co-based catalysts were discussed.关键词：Co-based catalysts;agglomeration;stabilization strategies;confinement;interactions80|0|0发布时间：2025-01-24 -
摘要：Fischer-Tropsch synthesis (FTS) can directly convert syngas derived from biomass into jet fuel, making it one of the most promising technologies for producing bio-based jet fuel. However, the selectivity of jet fuel in direct FTS is limited by the Anderson-Schulz-Flory (ASF) distribution law, posing a significant challenge in improving selectivity of jet fuel. Bifunctional catalysts, which couple FTS active centers with zeolite acid centers, enable the relay of CO hydrogenation with secondary reactions such as hydrocracking and isomerization, effectively controlling the selectivity for specific fractions. The mechanisms of bifunctional catalysts were introduced, and the reaction performances reported in existing studies were compared. The synthetic strategy and structure-performance relationship in different catalytic systems were emphasized, including the size effect, pore structure and acidity control of zeolites, as well as promoter effect. An outlook on the application of bifunctional catalysts for direct synthesis of jet fuel from FTS was provided.关键词：Fischer-Tropsch synthesis;jet fuel;bifunctional catalysts84|0|0发布时间：2025-01-24 -
摘要：The cycloaddition reaction of carbon dioxide (CO2) and epoxides is an effective method to synthesize cyclic carbonates. Catalysts are important for the activation of CO2 and epoxides in the reaction. A series of bifunctional Mn-based catalysts LnMn(CO)3Br (n = 1~6) were prepared by 2,2’-bipyridine with its derivatives as the ligands, Mn(CO)5Br as the metal source and ethyl ether as the solvent. The chemical structures, molecular weights and chemical groups of LnMn(CO)3Br were characterized by 1H NMR, 13C NMR, HR-MS and FT-IR, etc. The catalytic performances of LnMn(CO)3Br in the cycloaddition reaction of CO2 and epichlorohydrin and the adaptability of L1Mn(CO)3Br to a series of epoxide substrates were studied. The results show that the electron donating properties of electron donating groups (methoxy group, tertiary butyl and methyl group) in LnMn(CO)3Br and the positions of methyl group on the pyridine ring have influences on their catalytic performances. For the cycloaddition reaction of CO2 and epiglorohydrin, under the conditions of L1Mn(CO)3Br dosage (mole fraction) of 0.05%, reaction temperature of 125 ℃ and reaction pressure of 3.0 MPa for 1 h, the epiglorohydrin conversion rate and catalyst turnover frequency of L1Mn(CO)3Br are 42% and 840 h-1, respectively. L1Mn(CO)3Br has adaptability to the cycloaddition reaction of several epoxides. And the steric hindrance effects of the substrates have great influences on catalytic performance of L1Mn(CO3)Br.关键词：cyclic carbonates;bifunctional Mn-based catalysts;carbon dioxide;epoxides;cycloaddition reaction79|0|0发布时间：2025-01-24 -
摘要：Tailoring of the metal-support interaction is one of the important ways to improve the CO2 methanation performances on the supported Ni-based catalysts. A series of Ni/USY-X (X = 1, 3 or 5) catalysts were prepared by impregnation by adjusting the pH value of the solution. And CO2 methanation performances of catalysts were investigated. Ni/USY-3 catalyst showes excellent CO2 methanation performance with CO2 conversion rate of 84.5% and CH4 selectivity of 95.7% in stability test at the condition of 450 ℃ and 20 h. XRD, H2-TPR, SEM and TEM were used to characterize the structure and morphology of the catalyst, and the effects of impregnating solution pH value on the structure and CO2 methanation performances of the catalysts were systematically investigated at the microscopic level. The results show that under appropriate pH value control, the metal-support interaction is enhanced, the particle size of the active metal Ni particles is reduced, and the dispersion is enhanced. Furthermore, the reaction paths of catalyst were analyzed by in situ FT-IR. The results indicate that the Ni/USY-3 catalyst follows the formate pathway. The highly dispersed and small particle size of the active metal Ni particles provide abundant active sites for the timely hydrogenation of bicarbonate into the key intermediate monodontate, leading to achieving efficient conversion of CO2.关键词：CO2 methanation;metal-support interaction;acidity58|0|0发布时间：2025-01-24 -
摘要：Methyl levulinate is an important chemical product with broad application prospects in alternative fuels, pharmaceuticals and solvents. Four preparation methods of methyl levulinate were analyzed in detail, among which the direct catalytic alcoholysis of biomass has more development potential. Based on the biomass direct catalytic alcoholysis method and the types of catalysts, the research status and trend of the preparation of biomass-based methyl levulinate at home and abroad in recent years were summarized. The optimized reaction conditions and performances were summarized, and the application characteristics of each catalyst were analyzed. Finally, the existing problems in the preparation of biomass-based methyl levulinate were pointed out, and the future research was prospected: Focusing on the study of biomass alcoholysis mechanism, applying non-grain biomass, and developing green catalysts which are easy to industrialize.关键词：methyl levulinate;biomass;catalytic alcoholysis;acidic catalysts52|0|0发布时间：2025-01-24 -
摘要：Ethanol gas phase carbonylation is a non-petroleum route for the production of propionic acid, and Ni-based catalysts supported on activated carbon are widely used in this reaction. In order to enhance the catalytic activity, a series of Ni-X (X = Fe, Cu or Ce) bimetallic catalysts were prepared by further doping Fe, Cu or Ce on the basis of Ni-based catalysts. The effects of metal dispersion and Ni0 relative content n(Ni0)/n(Ni0 + Ni2+ + Ni3+) on the reaction performances were investigated by N2 physical adsorption/desorption, XRD, XPS, etc. The activity of Ni-X bimetallic catalysts for ethanol gas phase carbonylation was evaluated under the conditions of 250 ℃, 0.1 MPa and the feedstock (n(CO):n(C2H5OH):n(C2H5I) = 40:20:1) space velocity of 1.2 h-1. The results show that there exists a synergistic interaction between Ni species and CeO2 on the surface of the Ni-Ce bimetallic catalyst, which promotes the reduction of Ni2+ to Ni0 and the appearance of more active sites on the catalyst surface, as well as inhibits the surface accumulation of Ni metal and promotes the dispersion of Ni metal. Compared with Ni-Fe and Ni-Cu bimetallic catalysts, the Ni-Ce bimetallic catalysts have the highest catalytic activity, and the ethanol conversion rate, combined selectivity of propionic acid and ethyl propionate and combined space-time yield of the catalyst at 6 h are 70.9%, 28.0% and 220.4 mg/(g·h), respectively.关键词：bimetallic catalysts;ethanol;gas-phase carbonylation;dispersibility;active site;activated carbon64|0|0发布时间：2025-01-24 -
摘要：To address the shortages of traditional fossil fuel reserves and energy, it is necessary to further develop the utilization methods of renewable energy. Kitchen waste, as common organic solid waste in residential life, belongs to the category of renewable energy. Due to its high organic matter content and susceptibility to spoilage and bacterial growth, human have focused more on energy utilization of kitchen waste. Thermal conversion technologies are suitable as resource utilization methods for kitchen waste due to their short cycle and high efficiency, including incineration power generation technology, hydrothermal liquefaction technology, hydrothermal carbonization technology, traditional gasification technology and supercritical water gasification technology. Incineration power generation technology can quickly reduce kitchen waste and achieve the conversion and utilization of organic waste to generate power. Hydrothermal liquefaction technology and hydrothermal carbonization technology are environmentally friendly and have significant advantages in preparing high-quality fuels, respectively achieving efficient conversion of kitchen waste to bio oil and hydrothermal carbon. Traditional gasification technology and supercritical water gasification technology can convert kitchen waste to combustible synthesis gas, and they are relatively mature. Especially, supercritical water gasification technology has great advantages in the preparation of clean energy hydrogen from kitchen waste. Combined with the current status of technological development, the limitations of various thermal conversion technologies were pointed out and relevant suggestions were put forward. The future development directions of various technologies were discussed, to provide references for achieving energy utilization of large-scale kitchen waste.关键词：kitchen waste;thermal conversion technologies;incineration power generation;hydrothermal liquefaction;hydrothermal carbonization;gasification technologies43|0|0发布时间：2025-01-24 -
摘要：Utility optimization plays a crucial role in energy conservation and emission reduction. To effectively enhance the economic and environmental performance of the biomass gasification process for α-olefin production, a multi-objective optimization model for the life cycle utility system was constructed using the Non-dominated Sorting Genetic Algorithm II (NSGA-II), targeting minimal economic cost and environmental impact. Coal, natural gas, and non-condensable gas were selected as system fuels, with desulfurization and denitrification processes introduced to meet SO2 and NOx emission standards. The life cycle assessment results before and after optimization were compared to verify the effectiveness of the optimization method. The results indicate that, under cost-prioritized conditions, selecting coal and non-condensable gas as system fuels provides a more optimal solution, with an economic cost of 115.56 CNY/h. Under environment-prioritized conditions, selecting natural gas and non-condensable gas as system fuels is more advantageous, with an environmental impact assessment of 3.92 × 10-12 h-1. After multi-objective optimization (optimized scheme 2B), the global warming potential of the entire process, acidification potential, eutrophication potential and particulate matter are reduced by 24.54%, 30.55%, 4.20% and 71.03%, respectively, and improvements also observe in the assessments of other environmental impact categories. This validates the potential application of the optimization method in promoting the sustainable development transition of the α-olefin production process.关键词：life cycle assessment;biomass gasification;α-olefin production process;utility system;multi-objective optimization40|0|0发布时间：2025-01-24 -
摘要：The removal of oxygenated compounds is one of the critical challenges for the high-value utilization of Fischer-Tropsch (F-T) synthetic oil. The research progress on the extraction-based removal of oxygenated compounds from F-T synthetic oil was summarized. Firstly, the extraction performance and potential issues of various extractants were discussed, including traditional solvents such as sulfone, alcohol, amine, and ester compounds, as well as novel solvents such as ionic liquids and deep eutectic solvents. Subsequently, process flows suitable for removing oxygenated compounds from F-T synthetic oil, such as liquid-liquid extraction and extractive distillation, were briefly introduced. Finally, a summary and outlook on the extraction-based removal of oxygenated compounds from F-T synthetic oil were provided, aiming to offer insights for research and industrial applications in related technologies.关键词：Fischer-Tropsch synthetic oil;oxygenated compounds;extraction;ionic liquids;deep eutectic solvents2|0|0发布时间：2025-01-24 -
摘要：When the supported metal catalyst is used to catalyze the hydrogenation of sulfur-containing substrates, the activity of the catalyst can be deteriorated or even completely deactivated due to the strong adsorption of sulfur on the metal surface. Ru-based catalysts (Ru/α-MoC and Ru/β-Mo2C) supported by molybdenum carbide with different crystalline phases were prepared by over volume impregnation method and used to catalyze 5-nitrobenzothiazole (5-NBT) hydrogenation. The catalysts were characterized by SEM, XRD, HR-TEM and XPS, etc. The results show that the Ru loaded on α-MoC is atomically dispersed, while the Ru loaded on β-Mo2C is dispersed in the form of nanoparticles. Under the conditions of 80 ℃, 2.0 MPa H2, 3 mL ethanol, 10 mg substrate and 10 mg catalyst, the 5-NBT hydrogenation rate of Ru/α-MoC is 9113 μmol/(g·h) when the 5-NBT conversion rate is lower than 30%. After reaction for 40 min, the 5-NBT conversion rate of Ru/α-MoC is 100%. The result of hydrogen-deium exchange experiment confirms that α-MoC plays an important role in the activation (adsorption activation) of 5-NBT nitro group, while Ru promotes H2 dissociation. The synergistic effect of these two effects makes Ru/α-MoC show relatively higher catalytic performance in 5-NBT hydrogenation.关键词：catalytic hydrogenation;Ru-based catalysts;molybdenum carbide;5-nitrobenzothiazole hydrogenation67|0|0发布时间：2025-01-24 -
摘要：SF6 is a potent greenhouse gas, and its recovery from mixed insulating gases (SF6 volume fraction of 15% and N2 volume fraction of 85%) by adsorption separation offer both environmental and economic benefits. The recovery of SF6 using temperature swing adsorption (TSA) cycle was investigated. Adsorption data for SF6 on zeolite 13X from the literature were used, and the Langmuir model was applied to fit the data, and a TSA cycle model was established. A genetic algorithm was employed for multi-objective optimization of performance indices, and the TOPSIS was used to make decisions on the Pareto optimal solution set. The results show that the Langmuir model can accurately predict adsorption data, with a coefficient of determination (R2) greater than 0.98. In the Pareto optimal solution set, recovery rate and purity of SF6 exhibit a trade-off with exergy efficiency of cycle. When the decision weights of recovery rate, purity, and exergy efficiency in the objective function are assigned as 1:1:1, the optimal adsorption temperature is 293.00 K, and the optimal desorption temperature is 382.24 K. Under these conditions, the recovery rate, purity and exergy efficiency are 87.00%, 32.08% and 2.68%, respectively. The TSA cycle shows potential for application in the capture and recovery of SF6.关键词：SF6 recovery;zeolite 13X;TSA cycle;multi-objective optimization;Pareto optimal solution set;TOPSIS69|0|0发布时间：2025-01-24 -
摘要：The utilization of solid waste resources is of important significance. Waste clay brick was used as the raw material to synthesize high CO2 adsorption performance type A zeolite and A/X eutectic zeolite through the hydrothermal method. The effects of alkali to ash ratio (mass ratio), calcination temperature, crystallization temperature and crystallization time on the synthesis of zeolite from waste clay brick were investigated. The synthesized zeolites were characterized using XRD, XRF, SEM, N2 adsorption/desorption and FTIR. The results show that, with a fixed Si to Al ratio (mole ratio) of 1, the optimal morphology of type A zeolite and A/X eutectic zeolite is obtained under the conditions of an alkali to ash ratio of 0.6 and 1.6, respectively, calcination temperature of 750 ℃, crystallization temperature of 90 ℃ and crystallization time of 24 h. Testing reveals that their specific surface areas are 61.3 m²/g and 326.7 m²/g, and their CO2 adsorption capacities are 2.96 mmol/g and 3.22 mmol/g at 30 ℃ under a CO2 atmosphere (CO2 volume fraction of 10%), respectively. After five regeneration cycles, their adsorption capacities remain above 88% of the initial adsorption capacity. The CO2 adsorption mechanism of the two zeolites was studied through adsorption kinetics and rate-limiting diffusion models. It is found that CO2 molecules are adsorbed on the zeolites due to internal/external pore diffusion and intermolecular Coulomb forces, mainly through physical adsorption. This study can provide a reference for the synthesis and application of zeolites from waste clay brick.关键词：waste clay brick;type A zeolite;A/X eutectic zeolite;CO2 adsorption48|0|0发布时间：2025-01-24 -
摘要：In the spontaneous liquid-gas imbibition experiment, powdered porous materials tend to float on the liquid surface due to their low density and poor wettability, which restricts the liquid probe from entering their pores, making it impossible to characterize their microporous structure. By molding the powdered material using a binder, the spontaneous liquid-gas imbibition characterization of its microporous structure can be achieved. Two types of activated carbon (AC1 and AC2) with different pore structures were selected as raw materials. A solution of polyvinylidene fluoride (PVDF) in N,N-dimethylacetamide was used as the binder solution. The raw materials were crushed and then molded using a process that involved mixing, solvent removal, tableting and heat treatment. A particle strength tester, nitrogen adsorption analyzer, scanning electron microscope and self-made spontaneous liquid-gas imbibition device were used to investigate the effects of binder dosage and post-treatment temperature on the strength, pore structure, behavior of spontaneous liquid-gas imbibition, and microstructure of the molded activated carbons and their particles. The results show that the distribution of the binder within the pores of the powder can be regulated by adjusting the binder dosage and post-treatment temperature. Under optimized conditions, the binder dosages for molding AC1 and AC2 powders are 0.08 g/g and 0.10 g/g, respectively, and the post-treatment temperatures are 260 °C and 245 °C, respectively. At this point, the strength of the molded activated carbons exceeds 55.0 N/cm, meeting the requirements for spontaneous liquid-gas imbibition experiments. The microporous structure of the molded activated carbon particles is inherited from the powdered activated carbon, and their microstructure is similar to that of the raw activated carbon. The molded activated carbon particles’ equilibrium volumes of gas displaced by liquid reach the same level of that of the raw activated carbon. Due to a small amount of binder entering the larger pores of the powder, the initial rate of the spontaneous liquid-gas imbibition in the molded activated carbon particles shows a slight difference compared to that of the raw activated carbon particles.关键词：spontaneous liquid-gas imbibition;powdered activated carbon;molding with binder;microporous structure54|0|0发布时间：2025-01-24 -
摘要：The wide range of industrial applications of organic amine CO2 capture technology is limited due to its high renewable energy consumption, while organic amine CO2 absorption liquids catalytic desorption technology can achieve efficient organic amine regeneration and high purity CO2 desorption at low temperature by reducing sensible heat, vaporization heat and reaction heat. The research progress on technology of catalytic desorption of organic amine CO2 absorption liquids was reviewed.The characteristics of catalysts for desorption of organic amine CO2 absorption liquids and the mechanism of catalytic desorption of organic amine CO2 absorption liquids under the action of catalysts were analyzed, and the future development of catalytic desorption of organic amine CO2 absorption liquids was prospected.关键词：CO2 capture;organic amine;regeneration;catalytic desorption34|0|0发布时间：2025-01-24 -
摘要：Carbon capture, utilization and storage (CCUS) technology is the most straightforward and efficient end-of-pipe carbon reduction method. CCUS technology is essential to achieve “carbon peak and carbon neutrality” targets of iron and steel industry. Although CCUS technology has several demonstration projects in petrochemical and power industries, its application in the iron and steel industry is still nascent. CCUS technology principles, carbon emission characteristics of iron and steel enterprises and CCUS technology applications in the iron and steel industry were summarized and analyzed. The fundamentals of carbon capture, transport, utilization and storage technology in the CCUS process were outlined. The characteristics of carbon emission sources and the gas composition, conditions, and impurity content were analyzed. The key problems and development trends of CCUS technology in the iron and steel industry were summarized by analyzing the CCUS industrial application projects and tests conducted both domestically and abroad. Based on the overview of current state of CCUS technology applications and carbon emission source characteristics in iron and steel enterprises, the key technologies that should be prioritized for the promotion and implementation of CCUS projects in iron and steel industry were prospected, in order to further promote the development of CCUS technology in iron and steel industry.关键词：iron and steel industry;CCUS;carbon emission source characteristics66|0|0发布时间：2025-01-24 -
摘要：Different from crude oil and natural gas pipelines, it is necessary to pay attention to CO2 phase change under the combined effect of temperature and pressure during the shutdown process of supercritical CO2 pipelines. It is of great significance to master the temperature-pressure change relationship, initial gasification pressure and temperature and gasification degree during shutdown process, in order to predict pipeline safety status. Based on the KB CO2 pipeline of PetroChina Xinjiang Oilfield Company’s million-ton supercritical CO2 pipeline demonstration project, the pipeline hydrothermal model was established and solved to obtain the change of pressure, temperature, density, liquid-holding rate and phase state in whole pipeline after shutdown, and it is found that there is a positive correlation between density of fluid and pressure drop corresponding to unit temperature drop. Based on the Peng-Robinson equation of state, the functional expressions of pressure, temperature and density changes before fluid gasification were obtained, and this temperature-pressure relationship can be expressed as the slope value of phase migration path line in CO2 phase diagram. This value is mainly affected by fluid density, and the slope values corresponding to fluid densities of 500 kg/m3, 650 kg/m3 and 800 kg/m3 are 0.213, 0.325 and 0.473, respectively. At the same time, the equations for temperature and pressure during initial gasification of fluid and the prediction equations for change of liquid-holding rate after gasification were given. The intersection point of phase migration path line and gas-liquid equilibrium line in CO2 phase diagram is the initial gasification pressure and temperature points of fluid. After the gasification of CO2 fluid, the pressure and temperature state points will be shifted along the gas-liquid equilibrium line until the temperature is reduced to temperature of soil around pipeline. The derived formulas were verified using the industry-recognised OLGA software, and the errors between calculation values and simulation values are within ±4.00%. Finally, the formula was applied to predict the safety state of demonstration project’s during shutdown process. It is found that the pressure at the starting point of pipeline when gasification occurs is the highest. In order to avoid gasification at any point of pipeline, the pipeline needs to be restarted before the pressure drops to 7.0 MPa.关键词：supercritical CO2;pipeline transport;shutdown process;phase transition52|0|0发布时间：2025-01-24
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