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A review on the approaches to the production of vanadium metal Weiliang LU Ying ZHANG Pei SUN Shili ZHENG Shan QIAO Yang ZHANG Ping LI Yi ZHANG The Chinese Journal of Process Engineering    2021, 21 (10): 1117-1131.   DOI: 10.12034/j.issn.1009-606X.220294 Abstract （1417）      PDF （4507KB）（331）       Knowledge map    Save Vanadium metal, known as "industrial monosodium glutamate", is widely used in the fields of metallurgy, chemical engineering, aviation, energy, atomic energy, etc. Vanadium belongs to the rare reactive metals with a high melting point, and its production is difficult and costly. Currently, the main route for the production of high-purity V is the combination of the aluminothermic reduction of vanadium oxide and the vacuum melting purification of the crude V; however, this route is energy-intensive and low-yield. In order to reduce the production cost of metallic vanadium, many approaches to the production of crude vanadium have been proposed based on the thermodynamic stability of vanadium oxides and vanadium chlorides, including calciothermic reduction, magnesiothermic reduction, vacuum carbothermic reduction, silicothermic reduction, carbothermic reduction-nitridation-nitride thermal decomposition, molten salt electrolytic deoxidation, etc. The developed refining approaches includes molten salt electrolytic refining, iodide thermal decomposition, solid-state electro-transport purification, etc. This paper reviews the above methods comprehensively in terms of principles, technical features, effectiveness, and drawbacks. It is expected that this review will provide important guidance for the development and upgrading of the approaches for the production of high-purity V metal. It is believed that the application of vanadium will continue to expand with the achievement of high-end materials, which no doubt promotes the development of high-purity metallic vanadium production industry. Related Articles | Metrics

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Study on sulfur removal from ferric phosphate by high-temperature calcination Wenbo LOU Ying ZHANG Yang ZHANG Xiaojian WANG Jianzhong LI Shan QIAO Shili ZHENG Yi ZHANG The Chinese Journal of Process Engineering    2022, 22 (2): 268-275.   DOI: 10.12034/j.issn.1009-606X.221043 Abstract （1183）      PDF （1247KB）（205）       Knowledge map    Save Iron phosphate is the main material for the synthesis of lithium iron phosphate battery cathode material, which is mainly produced by co-precipitation method of using ferrous sulfate and phosphate salt. The sulfur content in the iron phosphate prepared by the co-precipitation process in the sulfate system is high, which has to be removed by washing with large amount of water of around 60~100 tons per ton of iron phosphate, bringing a huge burden of sulfate-bearing wastewater treatment. To reduce the amount of wastewater from the source, this research proposed an alternative way for desulfurization by high-temperature calcination based on the feature of sulfate decomposition at high temperatures. The thermodynamic feasibility and kinetics of the desulfurization were studied. The results showed that the sulfur in ferric phosphate existed in the form of sulfate, which can be effectively removed by high-temperature calcination. A higher temperature was preferred for a more satisfactory desulfurization efficiency. Kinetic study uncovered that the desulfurization reaction order was 2, and the activation energy was 88.075 kJ/mol, indicating a chemical reaction control mode. The sulfur content in iron phosphate can be reduced to less than 0.01wt% by calcining at 1173 K for 10 min. Related Articles | Metrics

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Research progress on reactive oxygen species and its detection methods Yaoyu HE Zhi JIANG Wenfeng SHANGGUAN Yunfa CHEN The Chinese Journal of Process Engineering    2021, 21 (12): 1403-1418.   DOI: 10.12034/j.issn.1009-606X.220423 Abstract （958）      PDF （1040KB）（202）       Knowledge map    Save Reactive oxygen species are kinds of highly reactive substances, including superoxide radicals, hydrogen peroxide, singlet oxygen, and hydroxyl radicals. Oxygen molecules, as oxidants, are more stable and need to be converted to highly reactive species before they can further react with other substances. In chemical reactions, especially catalytic oxidation reactions, the type of reactive oxygen species, its formation, and its diffusion behavior determine the direction and rate of the reaction. In the field of life sciences, reactive oxygen is involved in energy conversion, oxygen balance and other important physiological processes, which are closely related to aging and disease. However, due to its short half-life and strong reactivity, qualitative and quantitative testing of reactive oxygen species is difficult. Choosing suitable detection methods and improving the temporal and spatial accuracy of the detection is important for environmental chemistry and life science research. This work introduces and compares the basic principles, research advances, and applications of reactive oxygen detection methods in environmental and life fields, and compares the advantages, disadvantages, and applicability of various methods. The theoretical calculation and detection of oxygen species in heterogeneous catalysis are also introduced, and the future research direction of reactive oxygen species in catalytic oxidation and other fields is discussed. Related Articles | Metrics

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Evaluation of safety performance and thermal stability of hard carbon anode for sodium?ion battery Xinrong YANG Haiying CHE Ke YANG Chaoliang PAN Xiaozhen LIAO Zifeng MA The Chinese Journal of Process Engineering    2022, 22 (4): 552-560.   DOI: 10.12034/j.issn.1009-606X.220420 Abstract （800）      PDF （2636KB）（196）       Knowledge map    Save As a promising energy storage system, the sodium-ion battery has attracted wide attention due to its rich sodium resources and cost advantages in energy storage and low-speed electronic vehicle application. With the development of the sodium-ion battery industry, battery safety is one of the key issues which is often caused by the heat loss of battery cells. In this work, the safety factors of sodium-ion batteries were studied, including thermal stability of hard carbon materials, over-discharge test, safety test (extrusion and acupuncture, etc.), and thermal runaway test. According to the first cycle discharge curve of a hard carbon coin cell, the solid electrolyte interphase (SEI) of hard carbon in different discharge potentials with differential scanning calorimetry (DSC) at 0.9, 0.5, 0.15 and 0.01 V, respectively were studied. The results showed that with the increase of sodium embedded in the hard carbon, the position of the exothermic peak appeared earlier and became more obvious and the presence of electrolytes reduces the stability of hard carbon embedded with sodium. The safety performance of full sodium-ion batteries can be evaluated by calorimetric analysis of the thermal runaway process of batteries. 1 Ah soft package batteries were prepared to study the over-discharge test and safety test. Compared with the non-over-discharge cells, cells over-discharge to 0 V had little difference in cycle performance after 500 cycles. The current density (0.1 or 1 C) had no significant influence on capacity recovery and cycle performance of the battery. The extrusion and acupuncture tests showed that the sodium-ion battery had good safety performance as the batteries were no fire and no explode. In addition, the thermal runaway test as calorimetric analysis was generally carried out by an accelerating rate calorimeter (ARC). The ARC test showed that the onset temperature of detectable self-heating were 136.6, 131.6, 136.3, 128.2, 166.6 and 138.6℃ at 80% state of charge (SOC), 60% SOC, 50% SOC, 40% SOC, 30% SOC and 0% SOC, respectively. Moreover, the thermal runaway occurred at 240.9℃ only at 80% SOC. It proved that the safety performance of the sodium-ion battery was good and the sodium-ion battery had the best safety performance at 30% SOC. Related Articles | Metrics

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Research progress on synthesis and industrialization of fatty primary amines Jiasheng PAN Yaofeng WANG Shuangshuang MA Rui SUN Yuting TONG Qida DING Rui ZHANG The Chinese Journal of Process Engineering    2021, 21 (8): 905-917.   DOI: 10.12034/j.issn.1009-606X.220235 Abstract （718）   HTML （16）    PDF （1360KB）（337）       Knowledge map    Save Organic amines have a wide range of applications in chemical, pharmaceutical, life science and other fields. They can be used as raw materials for dyes, daily necessities, antibiotics, alkaloids, and clinical medicines. Among different amine compounds, primary amine is the most basic structural unit. Its application is also the most widely used in amine compounds. With the rapid development of economic and social as well as the improvement of people's quality of life, the market demand for primary amines, especially fatty primary amines, is increasing day by day. The synthesis and industrial preparation of fatty primary amines has become an important field. After decades of development, though the production technology of fatty primary amines has achieved great results, there are still some problems such as harsh reaction conditions, insufficient catalyst performance, serious pollution, complicated processes, etc. This work takes the industrial production and hot preparation methods of fatty primary amines as the research object, summarizes the process of preparing fatty primary amines in industry (including alkylation of organic halides with ammonia, reductive amination of alcohol, hydrogenation reduction of nitrile, direct amination of olefin, amination of carboxylic acid, etc.) and illustrates the practical application of each preparation method in industry production. It also analyzes and compares the advantages and disadvantages of each production method. Inferior, the current research hotspot-the method of preparing fatty primary amines by reductive amination of carbonyl compounds is described, and the potential and challenges of the preparation method in future industrial applications are pointed out. Related Articles | Metrics

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Preparation methods of g-C 3N 4 and its photocatalytic performance improvement approaches—a review Hanxiao DU Juan JI Chenwei QIN Ze ZHANG Fengfeng LI Yi SHEN The Chinese Journal of Process Engineering    2022, 22 (2): 162-175.   DOI: 10.12034/j.issn.1009-606X.221054 Abstract （698）      PDF （15934KB）（190）       Knowledge map    Save The polymer semiconductor g-C3N4 has attracted widespread attention in fields such as pollutant degradation and clean energy production due to its features such as narrow band gap, high stability, low cost, etc. However, there are some drawbacks of g-C3N4 that it has low charge separation rate, high charge recombination rate, etc., which lead to its unsatisfactory photocatalytic ability. Therefore, improving the photocatalytic performance of g-C3N4 has become a research hotspot in the field of photocatalysis. The g-C3N4-based photocatalysts prepared by heterojunction construction, elemental doping and other modification methods can enhance the absorption of visible light and have strong photocatalytic ability, which have wide industrial application prospects. In this work, firstly, the research actuality of g-C3N4-based photocatalysts was briefly introduced. Secondly, this work discussed the research status of preparation methods and introduced several preparation methods for g-C3N4. It also explained the problems that should be paid attention to when applying different preparation processes. In addition, various mechanisms of the approaches to improve its photocatalytic performance were illustrated, and the development directions were pointed out, summarized and prospected. In the follow-up research, if the advantages of material science and environmental science can be effectively combined to prepare g-C3N4-based photocatalyst composites with stable structure and excellent photocatalytic performance, it will be of great significance to improve practical value of g-C3N4. Related Articles | Metrics

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CO2 methanation: recent advances in catalyst development and reaction mechanistic study Junbo TIAN Fangna GU Fabing SU Zhanguo ZHANG Guangwen XU The Chinese Journal of Process Engineering    2023, 23 (3): 375-395.   DOI: 10.12034/j.issn.1009-606X.222027 Abstract （659）   HTML （28）    PDF （12772KB）（349）       Knowledge map    Save Choosing a suitable approach for CO2 utilization is crucial to achieving carbon neutrality and carbon peak goals as early as possible. Synthesis of synthetic natural gas (SNG) by methanation of CO2 using hydrogen produced from renewable energy is widely regarded as an efficient and promising carbon capture and utilization technology, which is expected to realize carbon recycling. Considering the importance of CO2 methanation, we provide a systematic review of the latest studies. Firstly, the effect of different reaction conditions on CO2 methanation is introduced from the perspective of thermodynamics. Secondly, the research progress of CO2 methanation catalysts is reviewed from four aspects: active metal, support, preparation method, and assistive technology. In detail, the active components are classified into cheap metal-based (Ni, Fe, Co, and Mo) and noble metal-based (Ru, Rh, Pt, and Pd) materials, and the supports are divided into the conventional oxides (Al2O3, SiO2, TiO2, ZrO2, and CeO2) and the supports with novel structures (e.g., metal-organic frameworks and carbon-based materials), which are all discussed and evaluated in depth. The preparation methods of catalyst are classified as the conventional ones (such as impregnation, coprecipitation, hydrothermal, sol-gel, and solid-phase synthesis) and unconventional ones. The latter includes three technologies such as ultrasound, microwave, and plasma, which can speed up the synthesis and reaction process and facilitate the high dispersion of the active components on the supports. Subsequently, two reaction mechanisms in CO2 methanation (the formate and CO pathways) are discussed. The specific reaction pathway for CO2 methanation is related to the properties of the catalyst surface (e.g., hydroxyl abundance, adsorbed O2- sites) and the reaction conditions (e.g., reaction temperature and pressure). Finally, current research challenges are put forward, and the prospects for future research in this area are made. Related Articles | Metrics

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Progress on catalysts for hydrogen production by low temperature methanol water reforming Zhan SHEN Zhidong JIANG Pengfei ZHANG Ziyu ZHANG Haiying CHE Zifeng MA The Chinese Journal of Process Engineering    2022, 22 (5): 573-585.   DOI: 10.12034/j.issn.1009-606X.221147 Abstract （640）      PDF （1690KB）（216）       Knowledge map    Save Methanol is a promising energy carrier owing to its simple structure, high hydrogen content and huge production capacity. Methanol steam reforming (MSR) is an energy-saving and efficient on-site hydrogen production method. Combined with fuel cells, MSR can be applied in many fields. However, due to the high reaction temperature (250~300℃), there are some problems such as slow start-up, high CO content and low thermal efficiency. Low temperature methanol water reforming (LT-MWR), including LT-MSR and aqueous-phase reforming of methanol (APRM), means that the reaction proceeds below 200℃, and maintains high reaction activity, which can reduce the preheating time and the side reactions, and achieve stronger thermal coupling with fuel cells. In this review, the performance and defects of commercial catalysts are firstly introduced based on characterization results. The research of LT-MWR catalysts for hydrogen production is reviewed, including Cu-based catalysts, noble metal catalysts and photo-synergistic catalysts. The modification strategies for low temperature Cu-based catalysts are summarized, including synthesis methods, structure design and element doping. The commercial CuZnAlOx catalyst at home and abroad has the characteristics of high methanol conversion and good stability, despite its relatively high price and low activity below 200℃. Because the activity of Cu-based catalysts is greatly affected by temperature, the catalytic activity decreases sharply at low temperature. By appropriate modification, Cu-based catalysts can perform high activity at low temperature. Noble metal catalysts have high activity at low temperature, but they are expensive and the synthesis process is complex. Photo-synergistic catalysts are functional under the condition of light, which is still in the research stage. The synthesis method can strengthen the micromixing degree and reproducibility. Appropriate structure design can increase the specific surface area and thermal stability of the catalyst. Element doping enables better dispersion of active components and modifies the surface structure. Three modification strategies can effectively improve the performance of Cu-based catalyst for LT-MSR, reducing the content of CO content while maintaining high activity. Finally, the prospect and challenges of LT-MSR catalysts for hydrogen production are prospected. Related Articles | Metrics

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Review of additives for electrolyte of sodium-ion battery Yuyue GUO Xiaoying ZHAI Ningbo ZHANG The Chinese Journal of Process Engineering    2023, 23 (8): 1089-1101.   DOI: 10.12034/j.issn.1009-606X.223104 Abstract （619）   HTML （33）    PDF （3494KB）（511）       Knowledge map    Save With the upsurge of the energy revolution, secondary battery as a new way of energy storage has been widely concerned owing to their efficient energy conversion. As we all know, lithium-ion batteries (LIBs) have high operating voltage and high energy density, they can be used in various application scenarios, such as electrical vehicles (EV), portable electronic devices, and large-scale energy storage systems. However, due to the shortage of lithium resources and rising prices of raw materials, many battery companies are observed to undergo cost pressure and bankruptcy risk. Given this, sodium-ion batteries (SIBs) work similarly to lithium-ion batteries, but they have great advantages in terms of resource reserve, low cost, low temperature, rate performance, and safety, thus have received strong attention from researchers and engineers. In the sodium-ion battery system, it is also composed of the positive electrode, negative electrode, electrolyte, separator, and other key components. The electrolyte, as the intermediate bridge connecting the positive and negative electrode material system, plays a vital role to undertake the transport of sodium ions, which mainly consists of organic solvent, sodium salt, and additives. The introduction of a small number of functional additives can significantly improve the overall performance of the battery because it constructs a solid electrolyte interface (SEI) between electrolyte and electrode. Different kinds of additives can exhibit specific properties to meet different conditions. This review focuses on the use of electrolyte additives, including unsaturated carbonates, sulfur compounds, phosphorus compounds, silicon compounds, inorganic sodium salts, and other types of components. Meanwhile, the research progress and related mechanisms of this addition agent in the electrolyte of sodium-ion batteries in recent years were summarized as a reference for subsequent research. Finally, the future study of electrolyte additives prospects from the science idea and practical application, for example, density functional theory, AI for science, and in-situ analysis method for SIBs. Related Articles | Metrics

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Review on progress of 5 V spinel Co-free LiNi 0.5Mn 1.5O 4 cathode material Jia JIN Jinping WEI Zhen ZHOU The Chinese Journal of Process Engineering    2022, 22 (4): 421-437.   DOI: 10.12034/j.issn.1009-606X.221115 Abstract （560）      PDF （11182KB）（434）       Knowledge map    Save As a candidate cathode material for next-generation Li-ion batteries or solid state batteries, the spinel LiNi0.5Mn1.5O4 is appealing researchers' interest. The 5 V spinel material of LiNi0.5Mn1.5O4 had ordered and disordered phases, and crystal structure, synthetic method and electrochemical reaction mechanism of which were discussed. Also, its electronic conductivity and lithium ion diffusion coefficient were highlighted compared with other cathode materials. The advantages of LiNi0.5Mn1.5O4, such as high discharge plateau, good rate performance, high thermal stability, abundant manganese resources and low cost, were introduced. Then technical obstacles hindering the industrialization of LiNi0.5Mn1.5O4 were discussed, including poor cycle performance at high temperature, low cycling coulombic efficiency, metal dissolution and phase transition, electrolyte decomposition at high voltages, gas generation in full cells. The main reason negatively affected the electrochemical performance of Li-ion batteries was electrochemical oxidation of carbonate esters at the LiNi0.5Mn1.5O4/electrolyte interface which resulted in Ni/Mn dissolution, crystal structural transformation and surface film formation, and eventually led to lower electronic conductivity and Li+ transport kinetics in Li-ion batteries. Some solution ideas were summarized at the material level, such as microscopic morphology control, new binder slurry strategy, doping, coating, high voltage matching electrolytes, synthetic control, and these material solution ideas should be coordinated with full cell design. In addition, this review speculated a few possible application scenarios on basis of its merits, for instance, start-and-stop power supply, low-temperature application, power tools and so on. Commercialization of LiNi0.5Mn1.5O4 relies on elaborate construction design at the battery level beside the materials design. More wide and thorough application research needs to be done to push the industrialization of LiNi0.5Mn1.5O4. Related Articles | Metrics

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Research progress on kinetic models of ethane pyrolysis Juan WANG, Haohan XU, Kai XIE, Haiyan YU The Chinese Journal of Process Engineering    2021, 21 (7): 752-761.   DOI: 10.12034/j.issn.1009-606X.220208 Abstract （545）   HTML （10）    PDF （904KB）（236）       Knowledge map    Save As the basic raw material for the production of various petrochemical products, ethylene plays an important role in the petrochemical field. With the global energy structure adjustment brought about by the shale gas revolution, ethane has gradually become the preferred raw material for ethylene production. Ethane pyrolysis technology has the advantages of high yield, low cost and low energy consumption. As the core content of cracking furnace mathematical model, the establishment of reaction kinetics model is the basis of simulation, control and optimization of cracking process. Therefore, under the current energy environment, it is of great significance for the development of domestic ethylene industry to study and summarize the kinetic model of ethane pyrolysis. In this work, the research status of ethane cracking process, pyrolysis reaction kinetic model and coking reaction kinetic model are summarized. The kinetic models of pyrolysis reaction are divided into empirical model, mechanism model and molecular reaction dynamics model. The kinetic models of coking reaction are divided into catalytic coking and free radical coking. This work not only introduces the basic models, but also compares and summarizes the process of gradual optimization of the models. In addition, this work puts forward new prospects for the future research direction. In the future, the combinations of the empirical model with the automatic control technology of cracking furnace and the reaction kinetics model with CFD technology are of great necessity. The co-cracking process of ethane and propane and optimization the product distribution needs to be further researched. The establishment of reaction kinetics model which can accurately predict the coking process need to be explored. In conclusion, ethane pyrolysis not only brings opportunities for industrial production, but also provides a new direction for researchers. Table and Figures | Reference | Related Articles | Metrics

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Peptide-drug conjugates improve the efficacy and safety of anticancer medicines Xue LIU Jing ZHANG Bo LIANG Yao ZHANG Weiying WANG Chun ZHANG Yongdong LIU The Chinese Journal of Process Engineering    2021, 21 (11): 1245-1258.   DOI: 10.12034/j.issn.1009-606X.220303 Abstract （541）      PDF （972KB）（177）       Knowledge map    Save Cancer has become the biggest threat to human health in the world. Small-molecule chemotherapeutic drugs are widely used in clinical practice in cancer treatment, but systemic toxicity and drug resistance are common due to the lack of tumor targeting. One of the main challenges for the chemotherapeutic drug is how to directly transport sufficient drugs to tumor but not normal tissues. To solve this problem, antibody-drug conjugate (ADC) was proposed and has been the hot spot in tumor drug research for decades. Guided by the specific monoclonal antibodies, ADC can selectively deliver highly cytotoxic drugs to tumor sites therefore overcome the above shortcomings of small molecules. However, the molecule weight of antibodies is generally large that makes ADC low permeability in the tumor and seriously limits its therapeutic effect. In recent years, peptide-drug conjugate (PDC), using peptides with tumor targeting ability to replace antibodies, is emerging as another novel targeted delivery route of tumor drugs. A great number of tumor targeting penetration peptides have been investigated in PDC design and shown great potential in cancer treatment. Peptides could be easily prepared through chemical synthesis or expressed by prokaryotic systems. Therefore, compared with ADC, PDC has the advantages of higher drug loading, enhanced penetration capacity in solid tumors, easier multifunctional modification through chemical or genetic techniques, and lower production cost. With the deep study of intracellular transport pathway and drug release mechanism, PDC will be expected to be put into clinical application as soon as possible. In this review, the latest advances of PDC are summarized. Types and characteristics of different targeting peptides, cytotoxic molecules and linkers in PDC and their applications in cancer treatment are discussed. The advantages and disadvantages of current researches on PDC are reviewed, and future development prospected. Related Articles | Metrics

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Synthesis and application of viologen-based electrochromic material Gaofeng ZHAO Weizhen ZHAO Xiaomin LIU The Chinese Journal of Process Engineering    2022, 22 (3): 304-317.   DOI: 10.12034/j.issn.1009-606X.221132 Abstract （515）      PDF （1614KB）（128）       Knowledge map    Save Viologen is a kind of compound with remarkable optical contrast, high coloring efficiency, unique redox stability. It's easy to be used for molecular design and large-area fabrication of devices. Due to its unique properties, viologen electrochromic materials have been widely used in military camouflage, screen display, information storage, intelligent dimming windows and other fields, and become one of the research hotspots. With the rapid development of smart materials, scientific researchers have gradually deepened their research on viologen-based electrochromic materials (including small molecule viologen derivatives, conjugated polymer functional viologen and viologen-based organic/inorganic composite material). In this review, the progresses of viologen electrochromic materials in recent years are reviewed, focusing on the synthesis and application of viologen, the application of ionic liquids or polyionic liquids in the field of viologen electrochromic, as well as the research status of enterprises and research institutions at home and abroad. The existing problems and potential applications of viologen electrochromic materials in the future are discussed from the perspective of industrial application. Related Articles | Metrics

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First-principles calculation of adsorption mechanism of hydrochloric acid on chalcopyrite surface Xiaoliang LI, Guocai TIAN The Chinese Journal of Process Engineering    2021, 21 (7): 836-846.   DOI: 10.12034/j.issn.1009-606X.220175 Abstract （502）   HTML （2）    PDF （1478KB）（151）       Knowledge map    Save The leaching of chalcopyrite has always been the core of copper sulfide hydrometallurgy, but chalcopyrite is a sulfide mineral that is difficult to be oxidized and decomposed. At present, a large number of macroscopic phenomena are obtained by focusing on experimental research, and the mechanism is mostly inferred. However, the lack of information on atomic or molecular level hinders the clear and effective explanation to these macroscopic phenomena. Therefore, it is necessary to study the surface interaction between liquid medium and chalcopyrite and the influence of medium on the formation of surface products by means of atomic or molecular level calculation and analysis, which are of great significance to reveal the reaction mechanism of leaching process and improve or develop a green hydrometallurgical technology of chalcopyrite. As a common leaching agent, hydrochloric acid can be used in the leaching of chalcopyrite, and it has been widely studied because of its advantages of recyclable leaching agent, high solubility of metal ions, good oxidation reduction performance and fast leaching rate. In this work, the adsorption and reaction mechanism of hydrochloric acid on different sites of chalcopyrite surface were studied with first-principles calculation. It was shown that the reconstructed sulfur terminated chalcopyrite (001) surface [labeled as (001)-S surface] led to the formation of disulphide S22-. Hydrochloric acid was adsorbed on the sulfur terminated surface (001)-S of chalcopyrite in the form of dissociation. In the process of leaching, the adsorption of H+ on sulfur terminated surface (001)-S of chalcopyrite destroyed the S22- formed on the surface. The surface structure of chalcopyrite (001)-S was destroyed by adsorption of chloride ion Cl-. During the adsorption process, the chemical reactions between H+ and Cl- with the surface of chalcopyrite produce the FeCl2 and H2S, which were both beneficial to the leaching of chalcopyrite. The results can provide a theoretical basis and guidance for future research. Table and Figures | Reference | Related Articles | Metrics

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Preparation of MgMn 2O 4 cathode material for aqueous magnesium ion batteries Wanquan LI Doudou ZHANG Shuqing DENG Mengting YUAN Yunlan CHANG Bing QIAN Yaxin SUN The Chinese Journal of Process Engineering    2021, 21 (9): 1091-1098.   DOI: 10.12034/j.issn.1009-606X.220218 Abstract （495）      PDF （1936KB）（172）       Knowledge map    Save Rechargeable magnesium ion batteries (MIB) as next-generation secondary battery systems have attracted increasing attention due to the high theoretical volumetric capacities, low cost and safety of Mg metal anodes. One of the key challenges in MIB is to develop cathode materials with higher specific capacity. Tetragonal spinel structure MgMn2O4 can be as MIB cathode material in aqueous electrolyte environments. However,the strong polarization and low kinetics diffusion of Mg2+ ion results a sluggish Mg migration in MgMn2O4. Herein, nanostructured MgMn2O4 samples were prepared via a simple sol-gel route followed by annealing using magnesium nitrate, manganese nitrate and critic acid as raw materials. The crystal structures and the morphologies of the products were analyzed by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). Electrochemical measurements of the products were carried out in a three-electrode breaker cell. The results showed that the samples annealed at 550℃ (MMO550) exhibited the maximum discharge specific capacity of 54.0 mAh/g at a current density of 40 mA/g, which was almost twice that of 750℃ samples (MMO750). The average grain size of MMO550 was about 30 nm analyzed by XRD and TEM, respectively. The MMO550 samples comprise microaggregated with channels and pores on the surface observed by FESEM, which were favorable for the effective contact between the electrolyte and particles. Further, nanocomposites of MgMn2O4 and carbon nanotube (MMO/CNT) obtained by annealing MMO550 with adding 5wt% CNT at a temperature of 400℃ for 2 h, exhibited the first discharge specific capacity of 118.0 mAh/g and capacity retention of 75% after 30 cycles. The Coulombic efficiency of MMO/CNT was very stable and above 95%. This outcome could be attributed to the improvement of conductivity provided by CNTs. FESEM and TEM results confirmed that CNTs can be acted as conductive grid connecting the MgMn2O4 particles effectively. Related Articles | Metrics

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Progress on biomethane production via biogas cleaning and upgrading Gama YANG Tingzhen MU Maohua YANG Delu MIAO Xuhao ZHAO Bin TANG Jianmin XING The Chinese Journal of Process Engineering    2021, 21 (6): 617-628.   DOI: 10.12034/j.issn.1009-606X.220154 Abstract （474）      PDF （556KB）（224）       Knowledge map    Save Biomethane is a kind of renewable fuel produced after the biogas is purified by desulfurization, decarbonization and dehydration. Its composition and calorific value are almost same as natural gas which means biomethane is a promising renewable energy to be used as vehicle fuel or injected to the natural gas grid. To enable the efficient use of biomethane in these applications the biogas must be cleaned and upgraded. Removal of H2S and CO2 are necessary processes for the commercial utilization of biogas and a number of techniques for transformation of biogas to biomethane have been developed. In this review, the main desulfurization and decarbonization technologies for the production of biomethane were systematically reviewed with their upgrading efficiency, methane (CH4) loss, energy requirement, environmental effect, development and industrialization. The technologies for the removal of H2S discussed in this work including absorption (physical and chemical), adsorption and biodesulfurization. And the technologies for the removal of CO2 including absorption (physical and chemical), pressure swing adsorption (PSA), membrane separation, cryogenic separation and the emerging biological methanation processes were discussed. Process flow and mechanism of each technology, as well as commercialization examples were introduced in detail with emphasizing their critical points and analyzing their advantages and deficiencies. Particularly, the review emphasized that biodesulfurization and biological methanation possess significant advantages over conventional physical/chemical technologies for biogas upgrading. Main advantages were that biotechnologies operated at normal temperatures and pressures, without the use of toxic complex chemicals, especially the biological removal of H2S in biogas had undergone a rapid development over the past 20 years and was nowadays commercially available and implemented in full scale facilities. The current challenges and future perspectives of biogas desulfurization and decarbonization processes were also discussed. Finally, the aim of the review was to provide process references for the research and industrial development of biomethane. Related Articles | Metrics

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Recent advances in catalysts for direct synthesis of cyclic carbonates from olefins and CO 2 Qilu HU, Guoying ZHAO, Caihong YU The Chinese Journal of Process Engineering    2021, 21 (7): 762-773.   DOI: 10.12034/j.issn.1009-606X.220195 Abstract （472）   HTML （7）    PDF （1153KB）（185）       Knowledge map    Save The valorization of CO 2  into value-added chemical compounds via economically viable process could be one of effective strategies to reduce CO 2  emission and therefore the climate change impact. The cyclic carbonates are industrially produced by cycloadditions between CO 2  and epoxides. However, there are safety risks in this technology due to the need to handle the flammable and explosive epoxides. Direct synthesis of cyclic carbonates from olefins and CO 2  could provide a safer, more economic and environment-friendly alternative technology. Herein, the latest research progress in catalysts for synthesis of cyclic carbonates via one-step oxidative carboxylation, sequential oxidative carboxylation and hydroxyl bromide carboxylation of olefins is summarized. The reported catalysts for oxidative carboxylation approach are mainly multi-component composite catalysts, of which include at least both catalytic components for epoxidation of olefins and carboxylation with CO 2 . Single component catalysts with catalytic active function or site for both epoxidation of olefins and carboxylation with CO 2 , have been rarely reported in the literature and are also described here. The catalysts for hydroxyl bromide carboxylation of olefins typically consist of a halogenating reagent and an inorganic/organic base deprotonating reagent. The effects of reaction approach, catalyst structure/components, catalytic mechanism and reaction conditions on the yields and selectivity of CC are also systematically summarized and explored. In the view of green chemistry, oxidation carboxylation of olefin is of higher atom-economy and environmental benefits while hydroxyl bromide carboxylation is always accompanied by the formation of a large number of side-products. An efficient heterogeneous single component catalyst with integrated cooperative catalytic active sites for epoxidation, carboxylation, CO 2  adsorption concentration, etc., which simplity the separation and recovery of catalysts and products, will be the future research trend of catalyst development for oxidative carboxylation of olefin with CO 2  to produce cyclic carbonates. Table and Figures | Reference | Related Articles | Metrics

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Research progress in preparation of large pore pseudoboehmite and γ-Al2O3 carrier Yongjia YANG Xinsheng ZHANG Jin LI Chunguang ZHANG Yuansheng ZHAO Shili ZHENG Ping LI The Chinese Journal of Process Engineering    2021, 21 (10): 1156-1166.   DOI: 10.12034/j.issn.1009-606X.220368 Abstract （462）      PDF （4364KB）（204）       Knowledge map    Save γ?Al2O3 is widely used as catalyst carrier in petroleum processing realm, owing to its porosity, high dispersibility, adjustable surface acid/base characteristics, attractive mechanical properties and good thermal stability. As the quality of crude oil is increasingly heavy and inferior, more and more attention has been paid on the preparation of macro-mesostructured γ?Al2O3 since the γ?Al2O3 as the catalysts carrier, that used in the heavy oil processing, such as fixed-bed residue hydrotreating or RFCC, need more meso-and macroporous structures to reduce the internal diffusion resistance of large molecules and improve the catalytic activity. Commonly, pseudoboehmite as the raw materials turns decisive significance for the physiochemical properties of γ?Al2O3. For instance, the pore properties of γ?Al2O3 are greatly in?uenced by the size and morphology of pseudoboehmite crystallites and their aggregation. This manuscript thus reviewed the representative preparation methods of pseudoboehmite including precipitation method and aluminium alkoxide hydrolysis method. The advances of Al2(SO4)3?NaAlO2 method and carbonization method, as two main industrial technologies, were emphatically introduced. New reactors and technologies for the precipitation were developed in order to provide su?cient mixing intensity and recirculation of different reactants, which could bring about a homogeneous supersaturation distribution in the instantaneous neutralization reaction, and then lead to uniform crystallites size, thereby pseudoboehmite with large pore volume and narrow pore size distribution. Besides, the relative meso??and macroporous structures control technologies were also highlighted, such as pH swing method, pore-enlarging additives method, and hydrothermal treatment method, etc. The advantages and disadvantages of these methods were also briefly analyzed. At last, the development trend was introduced and some suggestions were proposed. Related Articles | Metrics

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Preparation and electrochemical performance investigation of molybdenum dioxide nanorods Zengli GAO Shouzhi YI Haiyan TANG Hongbin XU The Chinese Journal of Process Engineering    2021, 21 (11): 1338-1345.   DOI: 10.12034/j.issn.1009-606X.220355 Abstract （462）      PDF （986KB）（315）       Knowledge map    Save With high conductivity, high melting point and large specific capacity, molybdenum dioxide (MoO2) nanorods have a wide application prospect in the field of electrode materials for supercapacitors. Although there are many methods to prepare MoO2 nanorods, most of them have disadvantages of a complicated process, low yield, high production cost and easy to introduce impurities. Moreover, the prepared MoO2 products have the characteristics of non-uniform morphology, poor dispersibility and inferior electrochemical performances. In this work, the precursor of peroxymolybdic acid prepared by hydrogen peroxide and molybdenum powder was used as the source of molybdenum, and PEG (8000) was used as the template. The molybdenum-containing hybrid with a band structure was prepared by mixing the precursor and template with stirring and thermal insulation. The nano-rod-shaped MoO2 was prepared through a two-stage hydrometallurgical process using the hybrid compound as raw material. X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), X-ray energy spectrometer (EDS) and scanning electron microscope (SEM) were used to analyze the phase, surface composition and morphology of the obtained MoO2 nanorods. The electrochemical capacitance behavior of MoO2 nanorods was studied using a three-electrode system and two-electrode system, and the performance of MoO2 nanorods as electrode assembly capacitors was also investigated. The results showed that the prepared MoO2 had a rod-like structure with 500 to 800 nm in length and with 100 to 200 nm in width. The MoO2 had uniform morphology and size with good dispersion and high purity. The specific capacitance of MoO2 nanorods was 366.7 F/g for the three-electrode system at the current density of 1 A/g, and the specific capacitance for the two-electrode system was 290.4 F/g, and the capacitance retention rate was higher than 72% after 2000 cycles of charging and discharging at 5 A/g current density, both showing the good electrochemical performance of MoO2 nanorods. The research results of this study can provide a new method for the preparation of other nano metal oxides. Related Articles | Metrics

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Research progress on synergistic extraction of typical organophosphorus extractant in solvent extraction Hao ZHANG, Guohua YE, Ziyang CHEN, Yu XIE, Qi ZUO The Chinese Journal of Process Engineering    2021, 21 (7): 741-751.   DOI: 10.12034/j.issn.1009-606X.220179 Abstract （453）   HTML （201）    PDF （1048KB）（183）       Knowledge map    Save As a branch of solvent extraction, synergistic extraction has been widely studied. In order to explore the mechanism of synergistic extraction, it is necessary to clarify the internal reasons of the extraction system and give the relationship between the micro and macro properties. Therefore, it is important to understand the synergistic extraction system and the influencing factors from the microscopic structure and internal movement of molecules. In this owrk, the mechanism of synergistic action between extractant, extractant and metal ions and the influencing factors were reviewed. It pointed out that the essence of synergistic extraction was the formation of hydrogen bonds, which led to the change of the structure and energy of extractant, thus improving the extraction effect. Synergistic extraction mainly includes two aspects: one is easier to generate stable extraction complex to improve the extraction efficiency; the other is to improve the separation performance by using the difference between extractant. The pH of the extraction system, the combination and proportion of different extractant, the concentration of extractant and the addition of neutral phosphorus extractant significantly affect the synergistic extraction process, and there are interactions among various factors. It will be one of the effective methods in the field of chemical research in the future to carry out theoretical prediction by simulation calculation, verify by experimental means, and characterize with modern analytical chemistry method. The theory is popularized to practice, so as to better guide the production. Table and Figures | Reference | Related Articles | Metrics

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Preparation of styrene acrylic resin composite with high thermal conductivity Fuhua JIA Bin GONG Qianyu WANG Duoyin ZHU Yanbin CUI The Chinese Journal of Process Engineering    2021, 21 (9): 1082-1090.   DOI: 10.12034/j.issn.1009-606X.220263 Abstract （451）      PDF （11921KB）（120）       Knowledge map    Save Styrene acrylic resin is the main component of toner. The thermal conductivity of toner could be improved significantly by increasing the thermal conductivity of styrene acrylic resin. Then, the life of printer and copier could be extended. By adding single or hybrid high thermal conductivity fillers of carbon nanotubes and graphene into styrene acrylic resin, a connected thermal conductivity network was constructed in styrene acrylic resin to improve the thermal conductivity. When 0.75wt% multi-walled carbon nanotubes (MWCNTs) were added into styrene acrylic resin, the thermal conductivity of styrene acrylic resin composite was increased from 0.1252 W/(m?K) to 0.1644 W/(m?K) with an increasing of 31.31%. When 1.0wt% MWCNTs-COOH was added into styrene acrylic resin, the thermal conductivity of styrene acrylic resin composites was increased to 0.1751 W/(m?K) with an increasing of 39.86%. When MWCNTs-COOH and graphene were added into styrene acrylic resin, the thermal conductivity of styrene acrylic resin composites was increased to 0.2093 W/(m?K) with increasing of 67.17%, which indicated the hybrid fillers (MWCNTs-COOH and graphene) formed connected thermal conductivity network in styrene acrylic resin. Thus, the thermal conductivity of styrene acrylic resin composite was improved significantly. Related Articles | Metrics

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Progress in boron recovery from salt lake brines by solvent extraction Zhenya XU Hui SU Jian ZHANG Wensen LIU Zhaowu ZHU Jinggang WANG The Chinese Journal of Process Engineering    2021, 21 (11): 1259-1268.   DOI: 10.12034/j.issn.1009-606X.220366 Abstract （451）      PDF （790KB）（226）       Knowledge map    Save In this work, four types of solvent systems for boron recovery from salt lake brines including aliphatic alcohol (monohydric alcohol, diol, mixed alcohol), aromatic polyhydroxy compound, amine compound containing hydroxyl group and ionic liquid were systematically reviewed, focusing on the recent research and application progress. The extraction mechanism of boron by various extractant systems were highly summarized to clearly explain the effect of extractant structures on the extraction performance. The extraction performance of different extractants and the influence of coexisting ions on the extraction process were analyzed, and the future research and development direction of boron extraction from salt lake brines were discussed. The monohydric alcohol was suitable for extracting boric acid under the conditions of high salting-out and acidity. But it also had serious disadvantages including low extraction rate, and severe equipment corrosion. Diol had higher extraction efficiency than monohydric alcohol, but it was difficult to realize large-scale industrial production due to high viscosity, high solution loss and difficult stripping from the loaded organic phase. Therefore, the recycling performance of diol extractant was relatively poor. The mixed alcohol system was suitable for industrial application of boron extraction from acid salt lake brines because of its synergistic extraction effect and low cost, and can also reduce viscosity and solution loss. Other systems, such as hydroxyl-containing aromatic and amine compounds, had good extraction effects on boron from alkaline salt lake brines, but they were generally expensive and difficult for industrial application. Ionic liquid can be used for boron extraction and diluent because of its advantages such as low volatility, good chemical stability and designable structure, which had a certain application prospect. Related Articles | Metrics

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Research progress of adsorption method to remove tetracycline from wastewater Xiong LAN Qin LIU Xintao ZHOU Zhongqiu LUO Xiaoteng ZHAO Yan LU The Chinese Journal of Process Engineering    2022, 22 (8): 989-1000.   DOI: 10.12034/j.issn.1009-606X.221261 Abstract （435）   HTML （16）    PDF （6695KB）（147）       Knowledge map    Save Tetracycline (TC) is a broad-spectrum antibiotic with large production and application at present. Its chemical properties are relatively stable and difficult to metabolize, so it is easy to accumulate in soil and water. The abuse of antibiotics not only increases the drug resistance of bacteria, but also produces resistance genes and induces the production of super-bacteria. Therefore, the harmless treatment of wastewater containing TC is urgent. Adsorption method has the advantages of easy operation, high removal rate, economy, and environmental protection. It is widely considered as an efficient method to remove antibiotics. The adsorption materials used to remove tetracycline from wastewater are different and various. This work mainly summarizes three kinds of common adsorbents: carbon materials, metal organic framework materials, and mineral materials. The adsorption capacity of the above materials for TC is listed, and the effects of pH value, temperature, ionic strength and other factors on the adsorption process of TC are analyzed. On this basis, the fitting of different adsorption kinetics and thermodynamic models when these three kinds of materials adsorb TC is analyzed. It is found that the adsorption kinetics of most materials meets with the quasi-second-order kinetic model, and the adsorption thermodynamics of the Freundlich thermodynamic model are better to describe the adsorption process. In addition, the mechanism involved in the removal of TC is also described. Finally, the advantages and disadvantages of these three kinds of materials in the study of TC adsorption are compared, and the future research focus is prospected, which provides a reference for accelerating the preparation of more economical, efficient and renewable TC removal adsorption materials. Related Articles | Metrics

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Ketopantoate production from glucose by combining biological and chemical steps Yao YAO Xiyang LU Lin SHU Qinghui WANG Shaoqi SUN Jian HAO The Chinese Journal of Process Engineering    2022, 22 (1): 97-107.   DOI: 10.12034/j.issn.1009-606X.221036 Abstract （433）      PDF （1822KB）（64）       Knowledge map    Save D-pantothenic acid (vitamin B5) is an essential vitamin to animals and has large markets in the feed, cosmetics, and pharmaceutical industries. The biochemical role of D-pantothenic acid in all organisms is to form the core of the structure of coenzyme A. Biosynthesis of coenzyme A from pantothenate occurs in all organisms, while the synthesis of D-pantothenic acid is absent from animals. Thus D-pantothenic acid is an essential nutrient to animals. Ketopantoate is an intermediate of pantothenate biosynthesis pathway. Ketopantoate can be stereoselectivity converted to D-pantoic acid and further used for D-pantothenic acid production. However, the economic production of ketopantoate is a bottleneck of D-pantothenic acid production from ketopantoate. Hence, this study provided a novel method for synthesis of ketopantoate by aldol reaction of α-ketoisovalerate and formaldehyde, and α-ketoisovalerate was produced from fermentation with glucose as the raw material. 25.2 g/L α-ketoisovalerate was produced by an engineering Klebsiella pneumoniae strain with glucose as the main carbon source. 19.9 g/L Ketopantoate was synthesized from formaldehyde and α-ketoisovalerate by an aldol reaction at basic conditions. The reaction parameters of reaction were optimized and a conversion ratio of 83.5% was obtained at reaction conditions of pH 13 and 45℃. The ketopantoate in the solution was converted to ketopantoyl lactone at acidic conditions of pH<3. Ketopantoyl lactone was extracted to isobutanol with an extraction rate of 50.9%. The organic phase was decolourized, and ketopantoyl lactone crystal was obtained after concentration. Ketopantoyl lactone was converted back to ketopantoate in an aqueous solution in the pH range of 7~10, and ketopantoate crystal was obtained after concentration. Ketopantoate production from glucose via α-ketoisovalerate as an intermediate was set up, which suggested a novel and competitive technical route to produce ketopantoate. The whole processes were combinated biological fermentation and chemical reactions and had a high conversion ratio. This method adopted renewable and cheap original materials rather than highly toxic raw materials. The optimal temperature of the reaction was 45℃, which was in mild conditions. Overall, a novel and promising method for ketopantoate and ketopantoyl lactone production was provided. Related Articles | Metrics

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Preparation of UiO-66 based catalyst and its performance for CO methanation Yong YANG Yong XU Guangjin ZHANG The Chinese Journal of Process Engineering    2021, 21 (9): 1074-1081.   DOI: 10.12034/j.issn.1009-606X.220314 Abstract （431）      PDF （2432KB）（138）       Knowledge map    Save Converting coal-based gas to natural gas has great economic and environmental benefits. As coal gasification technology matures, the CO methanation process acts as an important role. MOFs materials have shown excellent performance in many fields and have attracted more and more attention. Compared with conventional catalysts, UiO-66 is a Zr-based MOFs material with high specific surface area and good thermal and chemical stability, the active metal Ni has low cost and is equivalent to the catalytic hydrogenation ability of precious metals. In present study, a series of UiO-66 catalysts with Ni loading were prepared via ultrasonic impregnation method. Plenty of characterizations including XRD, BET, TG, SEM, TEM and XPS were used to study the structure, textual properties, thermal stability and morphology of the UiO-66 supported Ni-based catalysts. The catalytic performance of different catalysts was also evaluated in the fixed-bed reactor. The results showed that the Ni was reduced to metallic state in the prepared catalyst, the Ni metal was highly dispersed on the UiO-66 support and exhibited no significant effect on the framework structure and crystal morphology of the MOF material. The structure of the carrier did not change below 400℃. In the CO methanation reaction, the activation temperature of the Ni/UiO-66 catalysts gradually decreased with the increase of Ni loading content. At the same reaction temperature (320℃), the Ni content on different catalysts increased from 10% to 30%, the CO conversion increased from 10.7% to 89.7%.When the Ni content was 20%, the catalyst showed good stability during the reaction process. Meanwhile, the CO conversion on the Ni-based catalyst was much higher than that of the Fe-based and Co-based catalysts with the same metal content, indicating that Ni as an active metal had excellent catalytic performance in the synthesis gas to methane reaction process. Related Articles | Metrics

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Effects of hole distribution on flow field and noise for multi-hole plates Qian LI Hua JI Donglin FENG Ziyang ZHANG Zongxing DUAN The Chinese Journal of Process Engineering    2022, 22 (5): 601-611.   DOI: 10.12034/j.issn.1009-606X.221131 Abstract （430）      PDF （1788KB）（105）       Knowledge map    Save At present, the multi-hole plates with uniform hole distribution structure are widely used in the process industry to limit the flow and reduce the pressure, vibration and noise because of low manufacturing cost, simple structure, easy processing, easy installation and maintenance. In order to further improve the flow stability and reduce the flow noise, multi-hole plates of non-uniform hole distribution with different hole spacing, hole number, and hole diameter are designed with the equivalent opening diameter unchanged. Based on the numerical results, the velocity, pressure, reflux characteristics, jet convergence and flow development in the pipeline with different multi-hole plates are compared in detail to analyze the flow field characteristics. Moreover, the noise of multi-hole plates is numerically calculated by the acoustic analogy model. The observation points are set on the centerline and the section perpendicular to the flow direction to compare the spectrum characteristics and the overall sound pressure level. The numerical results show that the decrease of hole spacing with equal difference, the increase of hole number on the plate edge, and the increase of hole diameter without reducing the hole number can all effectively improve the flow stability and reduce the noise level of multi-hole plates without influencing the pressure drop ability compared with the general multi-hole plate with uniform hole distribution, and the maximum decrease of noise level is 5.62, 6.10 and 7.00 dB respectively. Related Articles | Metrics

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Review of heat treatment process for spent lithium-ion batteries: from the perspective of pollutant migration and transformation Hanlin HUANG Chunwei LIU Shaojie YAO Zhi SUN The Chinese Journal of Process Engineering    2022, 22 (3): 285-303.   DOI: 10.12034/j.issn.1009-606X.221070 Abstract （420）      PDF （2565KB）（137）       Knowledge map    Save Spent lithium-ion batteries have the dual properties of mineral resources and environmental pollution, they are not only rich in key metals with high external dependence in China, but also contain toxic and harmful substances such as heavy metals and organic pollutants. Efficient recycling of spent lithium-ion batteries is the key to ensure the sustainable development of strategic emerging industries such as electric vehicles. Lithium-ion batteries have various categories associated with complex structures and different organic compounds. Conventional pyrometallurgical and hydrometallurgical processes are likely to produce secondary environmental hazards, which affects the subsequent efficient recycling of metals. Heat treatment has attracted extensive attention in the industry in recent years, since it helps effective recovery of valuable metal resources. Heat treatment technology enjoys many advantages, such as little secondary pollution, attainable equipment, readily scaling up and low costs. Associated with the heat treatment method, the pollution control at the very beginning of recycling spent lithium-ion batteries can not only realize clean production, but also strengthen the subsequent in-depth treatment. Based on the current situation and strategic needs of the industry, this work focused on the generation, migration and transformation of pollutants in the pretreatment of spent lithium-ion batteries. The technical advantages of heat treatment were compared and summarized in the aspects of impurity removal and pollution prevention and control. Meanwhile, the heat treatment processes of spent lithium-ion batteries were systematically classified, and the material transformation mechanism under different heat treatment conditions was summarized. Related Articles | Metrics

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Simulation and experimental study of fluid flow in the bed of columnar particles in a tubular fixed bed reactor Zirui ZHU Xuedong LIU Liangxiong JIANG Yutong GU Tao PENG Junjie YIN Meihua LIU Wei JIANG The Chinese Journal of Process Engineering    2021, 21 (9): 1022-1032.   DOI: 10.12034/j.issn.1009-606X.220288 Abstract （416）      PDF （4564KB）（239）       Knowledge map    Save In view of the large number and large scale of tube bundles in the tubular fixed bed reactor, a single tube bundle was selected as the characteristic structure of the study. For the tube bundles filled with columnar particles of different diameters, the method of program coordinate positioning was adopted and the physical model of the columnar particle bed was established. DEM and CFD numerical simulation methods were used to explore the influence of the ratio of the inner diameter of the reaction tube to the equivalent surface area spherical equivalent diameter of columnar particles (Di/dp) on the fluid flow in the cylindrical particle bed. A single-tube fixed-bed reactor test device was established, and the differential pressure test method was used for experimental research. The results showed that when Di/dp increased from 5.37 to 12.75, the porosity of the bed and the uniformity of fluid distribution were improved, and the influence of the wall effect was weakened from the center of the bed to the tube wall. Based on the numerical simulation and experimental results, the bed pressure drop Ergun formula was corrected with constant coefficients for the columnar particle bed with Di/dp=12.75. The CFD simulation calculation results were in good agreement with the fitting formula. The research results provided guidance value for the design and application of fixed bed reactor. Related Articles | Metrics

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Research progress and application of heat transfer enhancement of twisted oval tubes Xiuzhen LI Yingying TAN Junfei YUAN Zhanwei WANG Lin WANG The Chinese Journal of Process Engineering    2022, 22 (5): 561-572.   DOI: 10.12034/j.issn.1009-606X.221153 Abstract （409）      PDF （6683KB）（229）       Knowledge map    Save The twisted oval tube has simple structure, excellent heat transfer enhancement and anti-fouling performance, and has become one of the research hotspots in the field of passive heat transfer enhancement. In recent years, researchers have carried out a lot of research on the heat transfer performance of twisted elliptical tubes (bundles) through experiments and numerical simulations. The mechanism of heat transfer enhancement is explained.Although there are reviews on the technology of twisted oval tube exchangers, there are deficiencies in the induction of the heat transfer enhancement characteristics of twisted oval tubes and the analysis of the research clues of the engineering application. This review focuses on the internal and external heat transfer and flow resistance performance of the twisted oval tube, and summarizes the influence of the structure of the twisted oval tube (bundle), working fluid and flow state on the heat transfer performance and flow resistance characteristics. The review also reviews the engineering application cases of twisted oval tube heat exchangers, and outlines the contents to be perfected in the researches on twisted oval tubes, and prospects the development trend of the research on heat transfer intensification of twisted oval tubes. This review is expected to provide guidance and reference for deepening the theoretical research and engineering practice of twisted oval tubes. Related Articles | Metrics

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Current application and development of microneedle Sibo ZHAO Yiru BAO Min XIE The Chinese Journal of Process Engineering    2023, 23 (2): 163-172.   DOI: 10.12034/j.issn.1009-606X.222114 Abstract （409）   HTML （160）    PDF （2905KB）（154）       Knowledge map    Save Microneedles are micrometer sized single needles or needle arrays that are produced by microfabricating techniques. Microneedles could penetrate the stratum corneum layer of the skin to reach the dermal layer which is favorable for percutaneous drug delivery. Microneedles have a number of advantages in drug delivery, compared with oral administration, microneedles circumvent the metabolic effects of the digestive system on drugs, compared with injection needles, microneedles are able to reduce pain and improve adherence compliance in patients. Due to their special transdermal pathway and precise, convenient application methods, microneedle has also become a hot studies area in biomedicine at present and their applications in vaccination, tissue fluid extraction and biomarker detection, etc. have been well investigated. According to working mechanisms for percutaneous drug delivery, microneedles can be classified as five kinds, including solid, coated, dissolving, hollow, and hydrogel microneedles. This review, combined with relevant articles in the field of microneedle technology in recent years, provides a brief overview of the types and fabricating materials of microneedles, mainly introduces the current applications of microneedles in the field of drug delivery (such as insulin injection for diabetes treatment, local drug delivery for cancer treatment, vaccination, tissue fluid extraction and biomarker detection, etc.) Besides, if the microneedles would be widely applied in the marker for medical application, some factors including mechanic strength, biological safety, sterilization process and biological stability of biomolecules on the micrneedles should be well considered which are also discussed in the review. At last, outlooks on microneedles' future development are prospected, such as developing microneedles based drug delivery system for heart attack treatment, improving biological stability of the biological molecules on the microneedles for convenient vaccination, and combining of microneedles with other techniques, such as sensitive biomarker detection method, microfluidic chip and wearable device, which will open a new prospect for the development of microneedles techniques. Related Articles | Metrics

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Research progress of continuous generation of microbubbles by microdispersion Bingqi XIE Caijin ZHOU Xiaoting HUANG Xiangdong MA Jisong ZHANG The Chinese Journal of Process Engineering    2021, 21 (8): 865-876.   DOI: 10.12034/j.issn.1009-606X.220341 Abstract （406）   HTML （179）    PDF （9216KB）（210）       Knowledge map    Save Microbubbles have been drawn more attentions due to their widely applications. At present, the preparation methods of microbubbles mainly include ultrasonic, electrolytic process, dissolved air flotation and microdispersion. Compared with traditional methods of microbubble generation, the microchannel technology has the advantages of high production efficiency, good controllability, excellent flexibility, which has been applied to produce the monodisperse microbubbles and drops. And the microchannels devices with different structures, such as co-flowing microfluidic, flow focusing, T-microchannel and venturi devices are an all-around introduced in this paper. In the process of gas-liquid membrane dispersion, the microbubbles size is affected by many factors, such as liquid flow velocity, liquid surface tension, liquid viscosity, the pore size, porosity, pore structure of membrane and gas flow velocity. So far, the mechanism of microbubbles formation is complicated, which is still not clear. Moreover, it is also critical important to rapidly and accurately measure the size and distribution of microbubbles due to the wide application of microbubbles. Traditionally, the size and distribution of microbubbles are measured by probes and laser particle analyzer, which is efficient and easy accessibility. However, the insertion of probes will affect the flow filed and the mechanism of lase particle analyzer is not clear. With the rapid development of digital image recognition technology, combination of high-speed camera and digital image recognition technology provides an effective, visual and accurate online microbubbles recognition method to measure microbubbles size. Furthermore, the application of deep learning technology in the recognition of microbubbles has drawn more attentions. In this work, the commonly characterization methods of microbubble size are summarized. In addition, the advantages and disadvantages of different methods of preparation microbubbles are also expounded and the current research status of microchannel method and gas-liquid membrane dispersion method are mainly introduced. On this basis, the future research directions of microbubbles prepared by microdispersion are prospected. Related Articles | Metrics

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Separation of low-concentration copper ions via the joint effect of electro-sorption and electrodeposition Meiqing HU Wei JIN The Chinese Journal of Process Engineering    2021, 21 (8): 976-984.   DOI: 10.12034/j.issn.1009-606X.220188 Abstract （403）   HTML （7）    PDF （1628KB）（154）       Knowledge map    Save Due to the significant importance in modern electronic devices and chemical products manufacture, considerable copper ions have been discharged into the global environment, which requires an effective way to remove and recover. Many conventional techniques have been explored, such as solvent extraction, ion exchange and precipitation. It has been demonstrated that electrodeposition is a promising way to recover copper ions as metallic products, however, it is difficult to directly use electrodeposition for copper recovery in acidic low-concentration copper-containing wastewater due to the performance of inefficient and time-consuming with low-quality products. To achieve efficient separation in the dilute wastewater system, a new stepwise method of electro-sorption and electrodeposition was proposed in this study. Initially, the ACF/CoS had been readily prepared as the low-cost and stable electrode, presenting excellent properties of a larger specific surface area of 33.2 m2/g and specific capacitance of 141.2 F/g at 5 mV/s. It can effectively recovery copper ions by electro-sorption method within 90 min, and the copper ion was concentrated from 30 mg/L to 500 mg/L after desorption and concentration process. Subsequently, it was connected to the turbulent reactor for enhanced electrodeposition, to overcome the bottlenecks of concentration polarization. The results showed that under the voltage of 0.25 V and the current density of 150 A/cm2, the recovery of copper ion can reach 99%, and the energy consumption was only 1.35×10?2 kW/h, which was 50% and 15% lower than the traditional electrodeposition and enhanced electrodeposition under the voltage of 0.40 V. Consequently, with the efforts of the effective electrode and improved mass transfer, the joint method of electro-sorption and electrodeposition exhibits a good prospect for the efficient treatment of low concentration metal wastewater and the recovery of low concentration metal ions. Related Articles | Metrics

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Numerical simulation of hollow catalyst with pores in gas-solid reaction system Qiuying WU, Lingkai KONG, Ji XU, Wei GE, Shaojun YUAN The Chinese Journal of Process Engineering    2021, 21 (7): 774-785.   DOI: 10.12034/j.issn.1009-606X.220229 Abstract （403）   HTML （14）    PDF （1654KB）（283）       Knowledge map    Save In the gas-solid flow, fluid and particle usually aggregate to form dense-phase and dilute-phase respectively, resulting in unbalanced mass transfer and reaction rates between the dense- and dilute-phase. The unbalance of dilute- and dense-phase reduces the overall efficiency of the reactor. To solve this problem, a hollow catalyst particle with pores structure is designed. It is aimed to enhance the overall efficiency of fluidized reactors by improving the mass transfer rate between the dense- and dilute-phase. Dense- and dilute-phase are widely distributed during fluidization processes, which can be respectively described by the cluster system and single particle system. In these two phases, the flow, reaction process and mass transfer process of hollow porous particles are studied by numerical simulation, and compared with the solid spherical particle system at the same fluidization condition. Then, the frequency of particle clusters formation and breakage is studied under various fluidization conditions. The time scale is analyzed to measure the possibility of gas transport in the fluidization process. It is found that the time-scales of the mass transfer, the reaction, and the movements of particles between the dilute- and dense-phase could be at the same order for some fluidization conditions. Thus, hollow porous catalyst particle can store the reacting material in the dilute-phase efficiently. When moving to the dense phase, the particle would release the reacting material to provide additional material for the dense-phase reaction. When the reaction is faster than the mass transfer, the overall reaction rate of the hollow porous catalyst system is 26.92%~29.55% higher than that of the solid spherical catalyst system at the studied conditions. It could be predicted that this hollow porous catalyst would be capable to improve the overall reaction efficiency of large gas-solid fluidized bed reactors due to wider distributions of the dilute- and dense-phase. Table and Figures | Reference | Related Articles | Metrics

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Research progress on sodium storage mechanism and performance of anode materials for sodium-ion batteries Cheng HAN Shaojie WU Chaoyang WU Mingyang LI Hongming LONG Xiangpeng GAO The Chinese Journal of Process Engineering    2023, 23 (2): 173-187.   DOI: 10.12034/j.issn.1009-606X.222083 Abstract （402）   HTML （13）    PDF （1833KB）（198）       Knowledge map    Save The massive use of fossil fuels is bound to cause irreversible damage to the global ecological environment. New energy sources such as solar, wind, and tidal have the advantages of being clean, non-hazardous, and renewable, and can be used to replace fossil fuels to alleviate the environmental crisis. The development and utilization of green energy have led to the rapid development of electrochemical energy storage and conversion technologies to store clean and renewable energy in the grid. Lithium-ion batteries, one of the most successful secondary ion batteries in energy storage, have been used in various electronic products, but expensive and scarce raw material resources limit their applications in the field of large-scale energy storage equipment. Therefore, the search for inexpensive secondary ion batteries with excellent performance is one of the hot research topics nowadays. As a new type of secondary ion battery, sodium-ion battery not only has a similar working principle as a lithium-ion battery but also features low cost, high resource abundance, and high reversible capacity. The extensive exploration by researchers is expected to make it a successful alternative to lithium-ion batteries for commercial production. This work mainly reviews the progress of the research on the performance of sodium-ion battery anode materials, firstly, the three mechanisms of sodium storage in the anode materials, namely the intercalation reaction, alloying reaction, and conversion reaction, are analyzed and summarized according to the different ways of sodium ion storage in the anode materials. Then, according to the performance of sodium-ion battery anode materials, three common modifications of anode materials are summarized: structural modification, elemental doping, and material compounding, and the electrochemical properties of anode materials before and after modification are compared. Then, the research status and problems faced by several key anode materials for sodium-ion batteries, such as carbon-based materials, titanium-based materials, alloy-based materials, conversion-based materials, and organic materials, are highlighted. Finally, the research directions of sodium-ion battery anode materials are prospected based on the actual production and industrial applications. Related Articles | Metrics

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Research progress of bubble separation behavior on electrodes and its strengthening technology Wei LIN Zhangwei WANG Wei WANG Jimin LI Zixin GUO Jin XIANG Xinyuan QIU Hongyang ZHAN Jiuyang YU The Chinese Journal of Process Engineering    2022, 22 (9): 1147-1158.   DOI: 10.12034/j.issn.1009-606X.221283 Abstract （401）   HTML （14）    PDF （3257KB）（166）       Knowledge map    Save The rapid development of the global economy inevitably caused the rapid consumption of fossil resources and serious environmental pollution problems. Hydrogen plays an increasingly important role in energy supply and environmental protection as a clean energy, water electrolysis is a way to produce hydrogen on a large scale, so it is very important to enhance the efficiency of water electrolysis for hydrogen energy production. How to improve the electrolysis efficiency of water electrolysis technology has been widely concerned. During electrolysis, the gas produced at both ends of the electrode can go in one of three directions: out of the cell, dissolved in the electrolyte, or attached to the electrode. However, in the electrolysis process, the bubbles attached to the electrode will seriously affect the contact area between the electrode and electrolyte, which directly reduces the electrolysis efficiency. Therefore, reducing the residence time of bubbles on the electrode can effectively increase the contact time between electrolyte and electrode and improve the efficiency of hydrogen production. In this work, the recent progress in promoting the separation of hydrogen and oxygen bubbles from the plate during electrolysis is reviewed. The nucleation, growth, coalescence and separation of bubbles are studied from the aspects of plate properties, current, solution concentration, and external physical field, and the characteristics of various methods to enhance bubble separation are discussed and summarized. The electrolytic efficiency can be improved and the energy consumption of electrolysis can be reduced by promoting the bubble separation on the electrode. The future development direction and route are prospected, this provides fundamental insight and direction for the future design of the bubble separation technology in water electrolysis. Related Articles | Metrics

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Research progress of thermal management technology for lithium-ion batteries Jiaxin LI Pengzhao LI Miao WANG Chun CHEN Liangyu YAN Yue GAO Shengchen YANG Manman CHEN Cai ZHAO Jing MAO The Chinese Journal of Process Engineering    2023, 23 (8): 1102-1117.   DOI: 10.12034/j.issn.1009-606X.223094 Abstract （396）   HTML （21）    PDF （13593KB）（209）       Knowledge map    Save Efficient battery thermal management technology is critical to the safe operation, long cycle life, and overall cost reduction of lithium-ion batteries and is important in promoting the large-scale application of lithium-ion batteries. In this review, several mainstream battery thermal management technologies are discussed in detail, including air cooling, liquid cooling, new phase change material cooling, and thermoelectric cooling technology. The battery heat generation model is briefly described. Finally, the development direction of battery cooling technology is prospected. Air cooling technology is simple in structure, but it is difficult to ensure temperature uniformity of the cells within the battery pack and is not suitable for cooling large lithium-ion battery packs, but is more suitable for small flying electric devices and low-end electric vehicles. Cooling plate liquid cooling technology is more effective, but there is a risk of coolant leakage and the temperature uniformity needs to be further improved. Immersion liquid cooling technology offers significant cooling and temperature uniformity but is expensive and is likely to be used more often in the future in energy storage plants with high cooling requirements, while for most lithium-ion electric vehicles the lower-cost cooling plate liquid cooling technology is more suitable. Phase change material cooling and thermoelectric cooling technologies without moving parts have achieved initial commercial application in electronic equipment and small power plants, but the cooling efficiency is low and needs further refinement. It is worth noting that it is critical to choose the right cooling technology for the user's needs. While there is no perfect cooling solution, a combination of cooling technologies can be used to meet the thermal management needs of a wider range of application scenarios. Related Articles | Metrics

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Study on oxyfuel combustion behavior and the intrinsic kinetics of typically sized coal particles Haolong BAI Liangliang FU Guangwen XU Dingrong BAI The Chinese Journal of Process Engineering    2022, 22 (8): 1115-1123.   DOI: 10.12034/j.issn.1009-606X.221256 Abstract （390）   HTML （5）    PDF （1151KB）（42）       Knowledge map    Save Oxyfuel combustion is a promising technology to facilitate carbon capture from combustion-generated flue gases. Circulating fluidized beds (CFBs), the major commercial-scale boilers, will play a significant role in the energy industry's transition from today's carbon-intensive to carbon neutral in the future. The types of boilers combust coals of wide screening particle sizes of 0~10 mm. The difference in coal particle size inevitably leads to a considerable variation in combustion characteristics, which has not yet been fully understood. In particular, little is known about the dynamic evolution behavior of combustion gas products and the intrinsic kinetics of the in-situ produced nascent char particles when these typically sized coal particles are combusted in fluidized beds. For this reason, an advanced micro fluidized bed reaction analyzer (MFBRA), integrated with a fast-responding process mass spectrometry, was employed to investigate the oxyfuel combustion behavior of two typically sized coal particles (i.e., 1.7~3.35 mm and 0.12~0.23 mm), typical of those in dense region and dilute region in CFBs, at 790~900℃. The use of MFBRA enabled the successful detection and characterization of the dynamic combustion process-sequentially occurring devolatilization and combustions of the in-situ produced volatiles and the nascent char particles. The results demonstrated that the combustions of volatiles and nascent char particles can have similar or different rates depending on the coal particle size. The two major successively occurring dynamic processes were distinctively identified and characterized for the coarse particles but not for the fine particles, which were featured with similar reaction rates for the two processes. The combustion of coarse char particles was rate-controlled by kinetics at low temperatures and changed to interparticle diffusion control at high temperatures. The combustion kinetics of the volatiles and nascent char were analyzed, and the corresponding values of activation energy were 107.2 and 143.9 kJ/mol, respectively. Related Articles | Metrics

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Extraction of vanadium and zinc by sulfuric acid leaching from descloizite Kelun ZHANG Bo LI Yonggang WEI Hongao XU The Chinese Journal of Process Engineering    2021, 21 (11): 1297-1303.   DOI: 10.12034/j.issn.1009-606X.220376 Abstract （389）      PDF （1180KB）（153）       Knowledge map    Save Vanadium lead zinc ore contains a variety of valuable metals with high V grade and high economic value. In this work, vanadium and zinc were extracted from the mine by sulfuric acid leaching method, and the thermodynamics of the leaching process was analyzed. The effects of sulfuric acid concentration, liquid-solid ratio, leaching time, stirring rate and leaching temperature on the leaching rate of vanadium, lead and zinc were studied through conditional experiments. The results showed that the hydrolysis of V in the leaching solution and hydrolysis products containing V remained in the leaching residue at high pH and higher temperatures, which affected the leaching rate of V. The optimum leaching conditions were as follows: sulfuric acid concentration 200 g/L, liquid-solid ratio 3:1, leaching time 30 min, stirring rate 200 r/min and leaching temperature 30℃. Under the optimum conditions, the V leaching rate was 97.90%, the Zn leaching rate was 97.11%, the Fe leaching rate was less than 1%, and the Pb leaching rate was less than 0.01%. The results of kinetic analysis showed that the reaction rate of leaching process was controlled by diffusion process. In the acid leaching process, V and Zn entered the leaching solution, and Pb and Fe remained in the leaching residue. The resulting leaching solution can be separated by ion exchange or extraction. The leaching residue contained 0.41wt% vanadium, 0.61wt% zinc, 15.50wt% iron and 47.70wt% lead. The main components were PbSO 4 and FeO(OH), which can be returned to the pyrometallurgical lead smelting system. Related Articles | Metrics

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Comparative study of fluid residence time distribution and flow pattern in baffle equipment Zhangfan GAO Muyi FAN Shaobei LIU Xiong ZOU Weixing HUANG The Chinese Journal of Process Engineering    2021, 21 (11): 1269-1276.   DOI: 10.12034/j.issn.1009-606X.220363 Abstract （389）      PDF （1447KB）（308）       Knowledge map    Save The flow pattern in the equipment can be the main performance index for its internal structure. Innovation of process equipment is to optimize its internal structure for desired flow pattern. Numerical simulation, as a primary research approach of fluid flow pattern, is not easy and economical to perform in large-scale or complex equipment, but the residence time distribution (RTD) experiment has the advantages of simplicity and convenience. In order to estimate the flow pattern with RTD experiments, taking the typical baffle structure as an example, several groups of structures were designed to compare and analyze the residence time distribution and the flow patterns corresponding to the structures, which can provide clues for short circuits judgement and determination of reasonable structures. The results showed that the short circuit and dead zone in the equipment were relativistic. The peak time and tailing of the RTD density function curve can be used to judge the short circuit and dead zone in the equipment. This conclusion can provide a theoretical basis for equipment design. The number of tanks in the multi-tank series model and the peak time and variance of the RTD curve were used to analyze the influence of flow rate, baffle gap area and plate spacing on the fluid flow pattern in the equipment. With the study of the pressure drop and the comprehensive consideration of the energy consumption and performance of the equipment, the most suitable tanks number, peak time and variance were put forward based on RTD experiments to determine the reasonable structure of the equipment, which provided a reference for the structural design of industrial baffle equipment. Related Articles | Metrics

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Theory of chemical reaction engineering on catalytic decomposition of propellant in packed bed for monopropellant thruster Baolin HOU Xue LI Wentao WANG Ting LU Weimin CONG Haolong WANG Deyang GAO Chuande HUANG Jihong SHAN Liangen XIA Xiaodong WANG Tao ZHANG The Chinese Journal of Process Engineering    2021, 21 (10): 1142-1155.   DOI: 10.12034/j.issn.1009-606X.220304 Abstract （379）      PDF （2128KB）（188）       Knowledge map    Save In 1960s, after the hydrazine based chemical monopropellant was developed, the liquid monopropellant technology has been widely applied in controlling the trajectory of satellite, adjusting the attitude of rocket and the emergency power supply. It is critical for chemical monopropellant to catalytically decompose the high energy liquid chemical propellant in the packed bed of particles. However, up to now, the kind of propellant technology had still been developed by performing a great deal of experiments under the direction of theoretical basement of thermal energy and air dynamics engineering and without considering from the viewpoint of chemical reaction engineering. In this work, from the viewpoint of chemical reaction engineering, the chemical engineering thermodynamics, the catalytic reaction kinetics, the diffusion-reaction in a single catalyst particle, the flow-reaction in the pore of porous catalyst, the flow-transport phenomena-reaction in the macroscopic porous media of packed bed and the meso-scale complicated geometry structure formed by the catalyst particles randomly stacking to be used in designing the component of propellant, optimizing the catalyst structure and the decomposition packed bed of monopropellant thruster were discussed. The review provides the fundamental theory of catalytic reaction engineering for designing, which is hoped as the theoretical direction for designing the propellant component, synthesizing the catalyst structure and the decomposition packed bed in developing the new green chemical monopropellant technology. Related Articles | Metrics