最新刊期
期 5 ， 2023
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摘要：As an important chemical raw material, linear α-olefins (LAOs) are usually used for the copolymerization of monomers and the synthesis of lubricants, plasticizers and oil additives. It is of great significance to use carbon dioxide (CO2) and hydrogen (H2) as raw materials to produce LAOs through CO2 hydrogenation reaction, which can alleviate the greenhouse effect and realize high value utilization of CO2. CO2 hydrogenation to LAOs generally consists of two steps: Reverse water gas shift (RWGS) and Fischer-Tropsch synthesis (FTS). Ferroferric oxide (Fe3O4) and iron carbide (χ-Fe5C2 et al.) can catalyze RWGS and FTS reactions, respectively, so Fe-based catalysts are currently the focus of research. The phase evolution process and deactivation mechanism of Fe-based catalysts were discussed. The effects of supports, promoters and surface modification on promoting the generation of χ-Fe5C2 active phase, regulating the ratio of Fe3O4/χ-Fe5C2 (mole fraction), and maintaining the stability of χ-Fe5C2 phase were emphatically analyzed. The main problems and future research directions of CO2 hydrogenation to LAOs on Fe-based catalysts were summarized.关键词：linear α-olefins;CO2 hydrogenation;Fe-based catalysts;active phases- 23
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发布时间：2023-10-26 -
摘要：The selective oxidation of methane to oxygenated compounds is considered a novel approach for the efficient utilization of natural gas resources. Recent advancements in both domestic and international research were reviewed, focusing on the selective oxidation of methane to methanol, formaldehyde, formic acid, and acetic acid. The active centers of catalysts, the active intermediates formed during the reaction, the reaction mechanism, and the structure-activity relationship of catalysts were analyzed. Furthermore, the future prospects for the selective oxidation of methane to oxygenated compounds were outlined. It can offer theoretical guidance for the design and development of highly active and selective catalysts for selective oxidation of methane.关键词：methane;selective oxidation;active intermediate;reaction mechanism;catalysts- 12
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发布时间：2023-10-26 -
摘要：Compared with the traditional methanol carbonylation to acetic acid in liquid phase, the green synthesis of acetic acid from syngas has the advantages of environmental friendeness and low cost, which have broad development prospects. The routes and catalysts research progress in green synthesis of acetic acid from syngas were reviewed. The design and optimization strategies of catalysts were expounded, and the influences of the properties of molecular sieve such as acidity and diffusibility on the reaction performance were discussed. Then, the influences of key conditions such as H2O content, n(H2)/n(CO) of feed gas, contact distance of active components, reaction temperature, and reaction pressure on reaction performance in the system were summarized. It is concluded that the key process for the green synthesis of acetic acid from syngas is the methanol carbonylation to acetic acid catalyzed by mordenite (MOR) molecular sieve. Increasing the number of acidic sites of MOR eight-membered ring and reducing the particle size of MOR to improve the spatiotemporal yield of acetic acid and the stability of catalyst are the key points of this process. This study provides some reference for the development of green synthesis of acetic acid from syngas with high selectivity, mild application conditions and cheap and easy available catalysts.关键词：syngas;acetic acid;methanol;green synthesis;carbonylation- 9
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发布时间：2023-10-26 -
摘要：The excessive release of carbon dioxide (CO2), a major greenhouse gas, has a severe impact on the environment and the world's climate. As a highly effective solvent and a significant chemical intermediate, N,N-dimethylformamide (DMF) is produced annually in quantities of up to one million tons. The utilization of catalytic technology in the synthesis of high value-added DMF from CO2 with dimethylamine (NH(CH3)2) offers a promising approach to reducing CO2 emissions, thereby contributing significantly to the sustainable development of society. Achieving efficient catalytic processes for the aforementioned reactions highly relies on the utilization of reactors. Three commonly used reactors (high-pressure reactors, fixed bed reactors, and slurry bed reactors) in the catalytic hydrogenation of CO2 to DMF were introduced, as well as their current application status. With its stainless-steel casing and inner liner that can withstand high temperatures and corrosion, the high-pressure reactor is suitable for the hydrogenation of CO2 to amide reactions containing amine raw materials, which requiring high-pressure conditions. The fixed-bed reactor can facilitate continuous reactions, but it is prone to hot spots leading to catalyst sintering, and it has no advantages in mass transfer. The slurry bed reactor boasts exceptional mass and heat transfer capabilities, akin to those of a high-pressure reactor, while also enabling continuous reaction over extended periods of time. High-pressure reactors remain the primary choice for the production of DMF from CO2 due to their ease of use, low cost, and versatility in application. As industrialization becomes increasingly relevant, the prospect of employing continuous evaluation devices, such as fixed bed reactors and slurry bed reactors, may emerge as the prevailing trend for future development.关键词：catalytic hydrogenation of CO2;DMF;high-pressure reactor;fixed-bed reactor;slurry bed reactor- 24
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发布时间：2023-10-26 -
摘要：Using zeolite-encapsulated strategy, the Ni-based catalysts with controllable structure was synthesized for the hydrogenation of CO2 to selectively obtain CH4 or CO. SiO2 nanospheres and silicalite-1 (S-1) zeolite molecular sieves were used as carriers to synthesize a series of Ni/X@S-1 catalysts with various Ni loadings by impregnation-recrystallization method (X is SiO2 or S-1 zeolite molecular). SEM results show that S-1 molecular sieves as the carrier is conducive to the subsequent crystallization to form the S-1 cladding layer, and when the amount of template agent tetra-propylammonium hydroxide (TPAOH) added is low (n(TPAOH)/n(SiO2) = 0.1), the Ni-species could be encapsulated by S-1 zeolite molecular sieves, and the outer surface of encapsulated metal catalysts is flat, exhibiting a regular hexagonal plate morphology. Experimental results of macromolecules liquid phase hydrogenation and energy spectrum analysis reveal that the Ni species are mainly distributed inside S-1 zeolite molecular sieves. The results of in situ XRD and H2-TPR indicate that the encapsulation of S-1 zeolite molecular sieves effectively enhances the interaction between NiO and carriers, inhibit the reduction of NiO towards metallic Ni (Ni0), which is beneficial to stable NiO phases. The results of CO2 hydrogenation indicate that without H2 pre-reduction, the CO selectivity of the main active phase of NiO (N-5.0% Ni/S-1@S-1) is 96.4%. After 400 ℃ H2 pre-reduction, the CH4 selectivity of the main active phase of Ni0 (R-5.0% Ni/S-1@S-1) is over 98.0%. NiO is the active phase for the formation of CO, while Ni0 is the active phase for the formation of CH4. The valence composition of active Ni species can be well controlled by tuning pre-reduction temperature to realize the selective generation of hydrogenation products CO and CH4.关键词：CO2 hydrogenation;Ni-based catalyst;zeolite encapsulation;in situ XRD;active structure- 24
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发布时间：2023-10-26 -
摘要：Ru promoter can improve the dispersion and reduction of Co species, inhibit sintering and carbon deposition, thus improve the structure of Co-based catalyst and its catalytic performance in Fischer Tropsch reaction. Co-based catalysts (Co/MgO, Co/MnO2, Co/NaY, Co/SiO2 and Co/ZnO, the loading amount (mass fraction, the same below) of Co is 30%) supported on different supports were prepared by coprecipitation method. Then RuCl3•xH2O was used as Ru promoter to modify the above Co-based catalysts and supported Co-based Fischer Tropsch catalysts modified by Ru were obtained by equal volume impregnation method with the loading amount of Ru is 0.5% and 1.0%, respctively. The structure of the catalysts were characterized by N2 adsorption, XRD and H2-TPR, and the catalytic performance of the catalyst in Fischer Tropsch synthesis were evaluated in a fixed bed reactor. The results show that different loading amounts of Ru promoter have different effects on Co-based catalysts on various supports. For all the catalysts, the specific surface area and pore volume decrease after impregnation with Ru promoter. H2-TPR characterization shows that Ru promoter can promote the reduction of Co species, lower the reduction temperature and inhibit the formation of refractory species between Co and the support. Co/MnO2 series catalysts show their activities at the temperature as high as 270 ℃, and 0.5%Ru-Co/MnO2 has the lowest methane selectivity (5.45%) and the highest C5+ selectivity (72.83%).关键词：Fischer Tropsch synthesis;Co based catalyst;oxide support;Ru promoter- 15
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发布时间：2023-10-26 -
摘要：The carbon dioxide-methane dry reforming (DRM) reaction for the synthesis of syngas (H2 + CO) is an important research direction for the resourceful utilization of carbon dioxide (CO2), with a key focus on carbon deposition control. Using FactSage software and employing the Gibbs free energy minimization method, a thermodynamic computational analysis of the DRM reaction and its carbon deposition control was conducted. The results indicate that under single-factor conditions such as high temperature (600 °C to 1200 °C), a feed ratio (n(CH4)/n(CO2)) of 1.00, and atmospheric pressure, favorable conditions for the DRM reaction can be achieved, leading to improved reaction conversion rates. By setting a carbon residue threshold at 0.01% (mole fraction), the critical conditions distinguishing between the carbon deposition and non-deposition zones are determined: a reaction pressure of 0.10 MPa, a reaction temperature of 900 °C, and the reaction falling within the non-carbon deposition zone when the feed molar ratio is less than or equal to 0.95. The research outcomes hold significant guidance for optimizing the operational parameters of DRM reactions and catalyst design.关键词：carbon dioxide;dry reforming of methane;carbon deposition control;thermodynamic analysis- 9
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发布时间：2023-10-26 -
摘要：In order to alleviate a series of serious environmental problems caused by greenhouse effect, it is urgent to reduce the main greenhouse gas, carbon dioxide (CO2) emissions. CO2 capture, utilization and storage (CCUS) technology has been widely used as an effective method to reduce carbon emissions. Among CO2 capture technologies, physical adsorption separation technology has the advantages of low energy consumption, stable product gas quality and strong adaptability, and can be extended to different industrial application scenarios. Three CO2 capture scenarios for adsorption and separation technologies: post-combustion flue gas capture, natural gas purification and direct air capture, and four kinds of CO2 adsorbent materials: porous carbon materials, zeolite molecular sieves, silicon-based materials and metal-organic framework materials were introduced. The applicable conditions and scenarios of the above materials were summarized, and the future development direction of CO2 adsorbents was prospected.关键词：CO2 capture;porous material;physical adsorption;pressure swing adsorption- 12
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发布时间：2023-10-26 -
摘要：Microencapsulated carbon dioxide (CO2) solid absorbents (MECS) is a novel CO2 absorption with considerable development potential. Compared with traditional chemical absorbent, MECS has many advantages including larger specific surface area, fast CO2 absorption rate, less loss of absorption, compact equipment and weak corrosiveness. The basic principles of CO2 capture process based on MECS were introduced, and the types and preparation methods of MECS were summarized from two aspects of core and shell materials. The important parameters such as CO2 absorption capacity, absorption rate, selectivity and regeneration performance of MECS in carbon capture research and the evaluation of its large-scale application were emphasized. According to the analysis, it is believed that the current research on MECS is still in the experimental stage, and to achieve large-scale application, future work should focus on material design, intelligent and controllable preparation method construction, carbon capture process optimization and so on.关键词：solid absorbent;CO2 chemical absorption method;microcapsule;CO2 capture- 4
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发布时间：2023-10-26 -
摘要：The excessive emission of carbon dioxide (CO2) has caused a series of serious problems such as climate change, ecological unbalance, ocean acidification and so on. CO2 capture and storage (CCS) technology is an effective means to alleviate the excessive emission of CO2 at present. Among CCS technologies, CO2 capture requires the highest cost. In order to effectively promote and apply CCS technology, emphasis should be placed on CO2 capture technology and materials to reduce the cost of this process. Among the three CO2 capture technologies, compared with pre-combustion capture technology and oxy-combustion technology, post-combustion capture technology has been widely used because of its mature technology and low requirements for equipment transformation. The research progress of CO2 capture materials after combustion was reviewed, including liquid absorbent (organic amine, ammonia solution and ionic liquid), solid adsorbent (biochar, zeolite, metal-organic frame materials, etc.) and membrane materials, and advantages and disadvantages of each materials were compared and analyzed. Finally, it was proposed that dry water can be used as a solid-liquid composite CO2 capture material because of its unique “solid-liquid” structure, which is expected to overcome the shortcomings of a single material and improve the CO2 capture efficiency.关键词：CO2 capture;liquid absorbent;solid adsorbent;membrane separation;dry water- 14
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发布时间：2023-10-26 -
摘要：Due to the rapid development of the social economy and industrialization, CO2 emissions are increasing day by day, leading to an increasingly serious greenhouse effect. Carbon emission reduction has become a global environmental problem demanding prompt solutions. Biological carbon sequestration technology has the advantages of economic sustainability and minimal side effects among the common CO2 removal methods. Microalgae carbon fixation technology achieves the purpose of carbon fixation through the photosynthesis mechanism of microalgae itself. CO2 is converted into cellular components like lipids and proteins, and each component can be further separated and extracted to make high-value-added chemical products. The whole process is safe and stable, which is of great significance in alleviating the greenhouse effect. The principles and advantages of microalgae photosynthetic carbon fixation technology and the application of biomass resources in various fields were expounded, and the influencing factors of microalgae carbon fixation efficiency were analyzed. Finally, the research status of photoreactors was summarized, and suggestions for the design optimization and development of photoreactors were proposed.关键词：microalgae;photosynthetic carbon fixation;CO2 concentrating mechanism;photobioreactor- 10
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发布时间：2023-10-26 -
摘要：Carbon capture technology is an innovative and directly effective carbon emissions reduction measure, holding significant importance for the steel industry's pursuit of “carbon neutrality”. An overview of four major carbon capture methods is provided, such as chemical absorption, physical absorption, physical adsorption and membrane separation. Their principles, advantages, disadvantages, domestic application cases, and common absorbents, adsorbents, and membrane materials are discussed. A summary of the development and application status of typical carbon capture technologies in the steel industry is also provided, including the chemical absorption methods such as the ESCAP process developed by Nippon Steel & Sumitomo Metal Corporation, the ammonia water chemical absorption process by Pohang Iron & Steel Company, and the alkanolamine chemical absorption process by Xinjiang BAYI Iron & Steel Co., Ltd., and physical absorption methods such as the pressure swing adsorption (PSA) process by JFE Steel Corporation and the temperature swing adsorption (TSA) + PSA process by Shougang Jingtang Iron and Steel Integrated Co., Ltd.. The steel industry has made certain progress in developing low-temperature regenerative absorbents and low-corrosive absorbents, improving the efficiency of physical adsorption methods, and reducing capture costs. However, the application of carbon capture technology in the steel industry is still at the early stage. To better promote the large-scale commercial application of carbon capture technology, several recommendations are proposed based on the unique characteristics of the steel industry.关键词：steel industry;carbon capture;chemical absorption;physical adsorption;development and application- 4
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发布时间：2023-10-26 -
摘要：The gas hydrate-based technology has been recognized as a promising technology for CO2 capture. It has the advantages of large gas storage capacity, mild formation conditions, and so on. Increasing hydrate formation rate and CO2 gas consumption are critical issues that need to be solved. The formation characteristics of CO2 hydrate in the activated carbon + THF solution system were studied. The effects of THF solution concentration (mole fraction, the same below) and THF solution saturation on CO2 gas consumption were explored. In addition, the growth morphology of CO2 hydrate formation in the activated carbon + THF solution system was investigated through the visual microscopic experiment. The results show that, compared with the system with the THF solution concentration of 5.56%, CO2 gas consumption obtained in the activated carbon + THF solution system (THF solution concentration is 5.56%, THF solution saturation is 100%) is increased by 59%. When the THF solution saturation is 100%, hydrate growth is found to be promoted with the increase of THF solution concentration. The time required for CO2 gas consumption to reach 90% of the total CO2 gas consumption (t90) is the shortest (106.67 min) with THF solution concentration is 5.56%. CO2 hydrate formation in the activated carbon + THF solution system is composed of the two stages of CO2 adsorption and CO2 hydrate formation. CO2 hydrate initially forms form at the interface of activated carbons particles and solution, and then gradually fills the interstitial spaces of the activated carbon particles. When the THF concentration is 5.56%, CO2 gas consumption decreased with the increase of THF solution saturation. The CO2 gas consumption is the largest under the condition of THF solution saturation 40%, and the corresponding t90 is the shortest (23.5 min).关键词：gas hydrates;CO2 capture;adsorption-hydration coupling method;THF solution;activated carbons- 13
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发布时间：2023-10-26 -
摘要：N-methyldiethanolamine (MDEA)/n-butanol/water phase change absorbent has good phase separation performance and has the potential to significantly reduce renewable energy consumption. Since n-butanol replaces part of the water in the phase change absorbent, and phase separation occurs during the absorption process of the phase change absorbent, the CO2 absorption performance and reaction mechanism of the solution are affected to a certain extent, and the transfer of the rich and lean interphase substances also has a certain impact on its kinetic performance. Therefore, the absorption properties of MDEA/n-butanol/water phase change absorbent were studied, and the material composition of the solution under different CO2 loads was tested by 13C NMR characterization, and the mass transfer-reaction mechanism was analyzed. On this basis, the kinetic characteristics were explored. The results show that the addition of n-butanol in the solution increases the initial CO2 absorption rate in the first 9 min of the solution. With the increase of n-butanol content, the CO2 absorption rate of the solution increases first and then decreases, and the CO2 absorption load gradually decreases. The physical solvent n-butanol does not participate in the reaction, and the reaction of MDEA with CO2 in the phase change absorbent follows the reaction mechanism of alkali catalyzed water. After phase separation, the lean phase solution is mainly MDEA, n-butanol and water, and the rich phase solution is mainly the reaction products of MDEA and CO2. At low CO2 absorption load (less than 1.12 mol/L), n-butanol improves the physical solubility of CO2 in solution, promotes the rapid reaction of MDEA with CO2 in the lean phase, and then promotes the dissolution of CO2 in the gas phase. The process of dissolution promoting reaction and reaction promoting dissolution makes the initial CO2 absorption rate of MDEA/n-butanol/water phase change absorbent higher than that of MDEA aqueous solution. At high CO2 absorption load (more than 1.45 mol/L), the phase separation degree of the solution is close to the ideal phase separation state, the water content in the lean phase is less, the concentration of MDEA in the rich phase is lower, and the concentration of reaction products is higher, which reduces the reaction rate of CO2 and the solution.关键词：phase change absorbent;CO2 absorptive property;reaction mechanism;kinetics- 2
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发布时间：2023-10-26 -
摘要：To address the problem of desorption and sequestration of CO2-rich absorption solution in the alcoholamine absorption method, the potential of absorption-mineralization of CO2 from mixed solution of ethanolamine (MEA) and N,N-dimethylethanolamine (DMEA) which coupled with purified dusts from calcium carbide furnace was investigated in detail. And the CO2 mineralization performance of this purified dust was compared with that of CaO and Ca(OH)2 at an equal adding proportion (n(CO2):n(Ca) = 1.0:1.0). The experimental results show that the CO2 absorption loads and desorption rate are the largest with the 1.5 mol/L MEA + 1.5 mol/L DMEA mixed solution, which are respectively 1.807 mol/L and 82.78%. The CO2 absorption performance decreases after four absorption-desorption cycles, but still has the CO2 absorption loads of 0.950 mol/L. The CO2 absorbed by MEA/DMEA mixed solution can be effectively desorbed and stored by purified dusts from calcium carbide furnace. The desorption performance of purified dusts from calcium carbide furnace for CO2 rich solution is similar to that of CaO but better than that of Ca(OH)2. The mineralization products consist three types of calcium carbonate which are aragonite, sphalerite and calcite. This is mainly due to the fact that the active calcium-containing components can release Ca2+ and OH- into the CO2 rich solution, and then they react with CO- 4
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发布时间：2023-10-26 -
摘要：Hydrogen sulfide (H2S) is a highly toxic and corrosive gas, even at low concentration levels, will have negative effects on industrial production, ecological environment and human health. Therefore, the removal of H2S from industrial gases is of great significance. In recent years, catalytic oxidation of H2S at room temperature (referred to as “catalytic oxidation of H2S”, the same below) have attracted extensive attention of researchers because of its low cost, high sulfur removal efficiency and the possibility of sulfur recovery. Porous carbon materials have the advantages of high specific surface area and large pore volume, and are suitable for catalytic oxidation of H2S. The mechanisms for catalytic oxidation of H2S by porous carbon materials were first discussed, and then the research progress of porous carbon materials that can be used for catalytic oxidation of H2S was reviewed. It is pointed out that the catalytic oxidation performance of porous carbon materials can be significantly improved by using different modification methods, such as heteroatom doping, alkaline solution impregnation and metal oxide loading. Finally, the key research points and the key scientific problems to be solved in catalytic oxidation of H2S by porous carbon materials were prospected, which can provide a reference for the future research of this field.关键词：hydrogen sulfide;porous carbon materials;catalytic oxidation;room temperature- 6
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发布时间：2023-10-26 -
摘要：In the context of “carbon peak” and “carbon neutral”, methane emission without restriction has received significant attention from countries around the world. Methane catalytic combustion can completely convert methane to carbon dioxide at a low temperature, which is an efficient and environmentally friendly purification technology. Pd-based catalysts are used in methane catalytic combustion due to the excellent catalytic performances, but their catalytic lifetime is still not satisfied with the requirement of industrial implication. Based on current research on methane catalytic combustion reactions, combined with papers published from 2019 to 2023 with the keyword “methane-combustion”, the active Pd species (Pd, Pdδ+, PdO and PdO-Pd), support types (Al2O3, CeO2 and molecular sieves) and catalytic stability (sintering resistance, water vapor resistance and SOx and H2S resistance) were reviewed, and the research prospects of methane catalytic combustion were prospected, which helps to promote sustainable environmental development of environment and the goal of energy conservation and emission reduction.关键词：methane catalytic combustion;palladium;active centers;support;catalyst stability- 27
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发布时间：2023-10-26 -
摘要：CH4/N2 separation is a key technology for the efficient utilization of natural gas, coal-bed gas, oilfield gas, biogas, and landfill gas. Existing research has mostly focused on the separation and purification of low-concentration CH4 (from 10% to 50%, volume fraction, the same below) in gas mixtures. In the case of CH4/N2 mixtures with high CH4 concentration (75%), the main objective is to enhance the CH4 purification effect of carbon molecular sieves. The preparation and modification of carbon molecular sieves, as well as the process conditions for pressure swing adsorption testing, were investigated. The results show that carbon molecular sieves prepared with benzene as the deposition agent under optimal deposition conditions (deposition temperature of 645 °C, deposition time of 60 min) exhibit the N2 adsorption capacity of 5.980 mL/g, and the corresponding N2/CH4 separation factor reach 6.970. Using the carbon molecular sieves prepared under the aforementioned optimal conditions as the adsorbent, the best single-tower pressure swing adsorption process conditions for adsorption pressure of 0.3 MPa, adsorption time of 60 s, and operation with normal releasing pressure to the set pressure then inverse releasing and vacuum, result in an increase of the CH4 concentration in the product gas to around 90% and a CH4 recovery rate of over 80%.关键词：carbon molecular sieve;pressure swing adsorption;carbon deposition;CH4/N2 separation- 46
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发布时间：2023-10-26 -
摘要：Coal bed methane is rich in methane (CH4), but it is mixed with a lot of air during underground mining, resulting in low CH4 concentration and difficult utilization. Therefore, the key to enrichment and efficient utilization of low concentrate coal bed methane is efficient separation of CH4 and nitrogen (N2). Activated carbon/metal organic frameworks (AC/MOFs) composite adsorbent materials were prepared from copper nitrate trihydrate (Cu(NO3)2•3H2O) and isonicotinic acid (HINA) by stepwise synthesis and characterised by X-ray diffraction, thermogravimetric analysis and scanning electron microscopy, and the gas adsorption properties, selectivity and heat of adsorption were investigated. The results show that the prepared AC/Cu(INA)2 composite material has characteristic diffraction peaks of AC and Cu(INA)2, and Cu(INA)2 growth on AC is observed. AC/Cu(INA)2 composite material has a CH4 adsorption capacity of 12.6 cm3/g at 100 kPa and 298 K, and a CH4/N2 selectivity of 5.5 (17.3% increase compared to the raw material AC). Additionally, the adsorption heat of CH4 (14.9 kJ/mol) is higher than that of N2 (11.9 kJ/mol).关键词：methane;nitrogen;activated carbon;metal-organic frameworks;composite materials;stepwise synthesis- 16
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发布时间：2023-10-26 -
摘要：The main processes for hydrogen purification via pressure swing adsorption of coke oven gas were presented, including hydrogen purification with reciprocating compressors, hydrogen purification with screw compressors, hydrogen and SNG (Substitute natural gas) co-production from coke oven gas, and steam reforming hydrogen production. The technical characteristics, process configuration, power equipment configuration, operational challenges, and maintenance difficulties of different processes were compared. The operating costs of various hydrogen purification processes were calculated. The results show that when the price of coke oven gas is 0.6 CNY/m3 and the electricity price is 0.5 CNY/(kW·h), the operating costs of hydrogen purification for the mentioned processes are all below 0.7 CNY/m3, making them relatively inexpensive sources of hydrogen. Among them, the processes using reciprocating compressors and screw compressors are characterized by simplicity, ease of operation, and low maintenance difficulty, making them more widely applicable.关键词：coke oven gas;hydrogen;pressure swing adsorption;process configuration;operating costs- 8
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发布时间：2023-10-26 -
摘要：In the industrial production of purified terephthalic acid, a significant amount of methyl acetate is generated as a byproduct. To efficiently utilize methyl acetate, a process utilizing transesterification and reactive distillation technologies has been proposed to convert methyl acetate and n-propanol into high-value n-propyl acetate and methanol, with rigorous steady-state modeling. To reduce utility consumptions during the separation process, pressure swing distillation and heat integration technologies were further employed to optimize the process with a feedstock of 50 kmol/h of methyl acetate. A comparative analysis of the process before and after optimization was conducted from both technical (systematic energy consumptions and CO2 emissions) and economic (total annual costs) perspectives. The results show that prior to optimization, the systematic energy consumptions of the process are 7.85 MW, CO2 emissions amount to 1.33 × 104 t/a, and the total annual cost is 4.71 × 106 CNY/a. However, following optimization, systematic energy consumptions decrease to 4.44 MW, CO2 emissions are reduced to 0.75 × 104 t/a, and the total annual cost decrease to 3.29 × 106 CNY/a. This study serves as a reference for the efficient utilization of methyl acetate and the industrial production of n-propyl acetate.关键词：transesterification;n-propyl acetate;reactive distillation;pressure swing distillation;techno-economic analysis- 5
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发布时间：2023-10-26 -
摘要：Using Xishan coking coal as the experimental material, a two-stage coal coking and dry distillation gas continuous thermal reforming experimental apparatus at a laboratory scale was employed to investigate the transformation behavior of dry distillation gas under high-temperature conditions. The primary focus was on the impact of varying oxygen (O2) flow rates on the composition and yield of effective components in the reformed crude gas. Simultaneously, the reaction conditions were optimized, proposing a staged oxygen feeding mode corresponding to changes in dry distillation temperature (The temperatures are below 400 ℃, between 400 ℃ and 700 ℃, between 700 ℃ and 900 ℃, and above 900 ℃, with O2 flow rates of 100 mL/min, 125 mL/min, 100 mL/min, and 50 mL/min, respectively). The results demonstrate that under staged oxygen feeding in thermal reforming, precise control of O2 supply during the reforming process is achieved, preventing the overoxidation reaction of effective gas (CO + H2) and carbon deposition. While reducing the consumption of O2 in thermal reforming, the yield of effective gas increases from 51.24 L to 98.42 L, representing a 92% increase in efficiency. Using a 500 × 104 t coke oven modification project as an example, the application of non-catalytic continuous thermal reforming for upgrading coke oven raw gas can yield additional benefits of up to 1362 × 104 CNY/a.关键词：coke oven raw gas;non-catalytic;continuous thermal reforming;experimental research;process verification- 2
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发布时间：2023-10-26
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