Most Download articles

Published in last 1 year | In last 2 years| In last 3 years| All| Most Downloaded in Recent Month | Most Downloaded in Recent Year|

In last 2 years

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

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 （1389）   HTML （75）    PDF （3494KB）（1399）       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

Select

Advances in biosynthesis of diamine as core monomers of new nylon materials Kun LIN Zhuang LI Kun WANG Ying BI Xiuling JI Zhigang ZHANG Yuhong HUANG The Chinese Journal of Process Engineering    2023, 23 (7): 958-971.   DOI: 10.12034/j.issn.1009-606X.223147 Abstract （761）   HTML （25）    PDF （1140KB）（598）       Knowledge map    Save In the context of carbon neutrality, bio-diamine synthesis is an effective way to achieve the low-carbon production and sustainable development. Using synthetic biology, metabolic engineering, protein engineering strategies, we are able to design and construct efficient key enzymes and pathways for the biosynthesis of diamines. In this work, the progress of diamine synthesis is reviewed around two synthetic strategies: microbial de novo fermentation and whole-cell catalysis. The main diamines include 1,4-butanediamine, 1,5-pentanediamine, and 1,6-hexamethylenediamine. The biosynthesis of butanediamine mainly includes ornithine decarboxylation and lysine decarboxylation pathways, and butanediamine is mainly produced by fermentation. However, the current yield of butanediamine is low and cannot meet the requirments of industrial production. The biosynthesis of pentanediamine depends on the decarbosylation of L-lysine, mainly by de novo fermentation and whole-cell catalysis. The whole-cell catalysis for pentanediamine is more efficient, which has been widely used in large-scale production with the maturity of the technology. Hexamethylenediamine is currently synthesized by constructing artificial pathways. In addition, to address the challenges encountered in the biosynthesis of diamines, such as many by-products, poor strain activity, low yield, difficult separation, and purification, we proposed methods to improve the biosynthesis of diamines by combining metabolic engineering and protein engineering to optimize key enzyme catalysis, exploring the mechanism of cell damage caused by diamine accumulation, enhancing the specificity and activity of enzyme catalysis to improve production intensity, and optimizing the fermentation system to simplify the subsequent separation and purification steps. Finally, we foresee the future direction and development prospect of diamine biosynthesis. Related Articles | Metrics

Select

Research progress in modification of layered oxide cathode materials for sodium-ion batteries Miaomiao LI Xiangyun QIU Yanxin YIN Tao ZHANG Zuoqiang DAI The Chinese Journal of Process Engineering    2023, 23 (6): 799-813.   DOI: 10.12034/j.issn.1009-606X.222296 Abstract （776）   HTML （110）    PDF （47402KB）（553）       Knowledge map    Save Sodium-ion batteries (SIBs) have been regarded as the major candidate technologies for large-scale energy storage applications due to the rich abundance of Na sources, low cost and safety. And the development of cathode materials also determines the final performances and commercialization. Layered oxide cathode materials have the advantages of high specific capacity, simple structure and good stability. It is one of the most promising sodium cathode materials at present. However, such materials are still faced with irreversible changes in the electrochemical process, unstable storage in air and poor interface stability, which seriously restricts the development of commercialization of SIBs. In order to solve these problems of materials, researchers modified and optimized them. Accordingly, the modification measures of ion doping, surface coating, nanostructure design and P/O mixing and other related modification measures of sodium electric layered oxide cathode materials, which provides a basis for the modification research of sodium electric layered oxide cathode materials are reviewed in this review. Besides, the future development trend of layered oxides is prospected. Related Articles | Metrics

Select

Study on curing arsenic-containing compounds and solid wastes by iron-based silicate gel Boyu DU Chao LIU Xing ZHU The Chinese Journal of Process Engineering    2023, 23 (12): 1714-1724.   DOI: 10.12034/j.issn.1009-606X.223085 Abstract （227）   HTML （6）    PDF （2442KB）（491）       Knowledge map    Save During the mining and metallurgy of non-ferrous heavy metals, a large number of arsenic-containing compounds are exposed to the environment, posing great environmental risks to the surrounding water and soil. Due to their good arsenate affinity, iron ions and their compounds are the main components of commonly used chemical arsenic fixation agents. Whether in arsenic pollutant solidification or arsenic-contaminated site remediation, silicate and hydration processes are important physical barriers to arsenic. Based on this, we synthesized an iron-based silicate gel and evaluated its performance for the solidification/stabilization of typical arsenic compounds [Na3AsO4, Ca3(AsO4)2, AlAsO4, and FeAsO4·2H2O] and arsenic-containing sludge from non-ferrous metallurgy, and explored the arsenic fixation mechanism. The results showed that the iron-based silicate gel with a Fe/Si molar ratio of 1:4 could effectively immobilize the arsenic-containing compounds (Na3AsO4 and FeAsO4·2H2O). However, in the process of curing Ca3(AsO4)2 and AlAsO4, due to the competitive reaction between arsenate and silicate, the toxic leaching of arsenic was higher than that in the process of uncaring. The introduction of CaO could inhibit the competitive reaction, improve the arsenic fixation rate of Ca3(AsO4)2 and AlAsO4, and reach more than 98% of the arsenic fixation efficiency. The synergistic effect of Fe and Ca co-precipitation and physical immobilization is responsible for the immobilization/stabilization of arsenic-containing compounds. The core-shell structure with arsenic-containing compounds as the core and iron-based silicate gel/C-S-H gel as the shell separated arsenic species and reduced toxic leaching when in contact with the surrounding environment. The long-term stability showed that the iron-based silicate gel-cured arsenic-containing waste remained highly stable at pH=8 for 30 days. The CaO-assisted iron-based silicate gel proposed in this work showed great potential for the immobilization of arsenic-containing wastes and arsenic-contaminated land and provided a new way to solidify arsenic-containing pollutants. Related Articles | Metrics

Select

Study on the mechanism of Ni2+ and Mg2+ loss and enhanced separation in sulfuric acid leachate of laterite nickel ore during iron removal using neutralization process Hao JIANG Xin TENG Jun LUO Changye MANG Xinran LI Wenhao SUN The Chinese Journal of Process Engineering    2023, 23 (11): 1558-1567.   DOI: 10.12034/j.issn.1009-606X.223055 Abstract （327）   HTML （9）    PDF （8323KB）（451）       Knowledge map    Save Neutralization precipitation process is often used to remove impurities such as iron, aluminum and chromium from the nickel laterite acid leach solution, however, it accompanied with the loss of nickel and magnesium metal ions. The precipitation behaviors of Ni2+ and Mg2+ ions in nickel laterite acid leach solution during the neutralization precipitation iron removal process was deeply discussed in this work. Furthermore, a novel precipitation mechanism of Ni2+ and Mg2+ with SO42- during the neutralization precipitation iron removal process was proposed. The results showed that under the condition of fixed Ni2+ and Mg2+ concentrations in simulated leachate, the loss rate of Ni2+ and Mg2+ during neutralization and precipitation respectively were 9.13%~23.23% and 9.79%~15.68% with the increase of Fe3+ concentration in simulated leachate. Under the condition of fixed Fe3+ concentrations, the loss rate of Ni2+ and Mg2+ decreased with the increase of the concentration of Ni2+ and Mg2+. According to the results of solution chemical calculation and the characterization of iron hydroxide precipitation by infrared spectroscopy and scanning electron microscopy, both SO42- ions and Fe(OH)3 colloids could co-precipitate in the form of monovalent or binary complex during the neutralization process, in which the lone pair electrons of SO42- in the monovalent complexes bond with Ni2+ and Mg2+ and adsorb, resulting Ni2+ and Mg2+ in the leachate were co-adsorbed with SO42- by Fe(OH)3 colloid and the loss was caused. In addition, it was found that the surfactant such as cetyl trimethylammonium bromide (CTAB), polyethylene glycol (PEG), sodium dodecyl benzenesulfonatecan (SDBS) was added during the neutralization precipitation process can effectively compete for adsorption with neutralizing precipitated products or impede the combination of SO〖_4^(2-)〗 with Ni2+ and Mg2+ ions, which could enhance the selective precipitation of Fe3+ ions during neutralization process. When the dosage of three surfactants was 2×10-5 mol/L, the retention rates of Ni2+ in the process of neutralization and precipitation of iron could reach about 95%, and Mg2+ could reach 100%. Related Articles | Metrics

Select

Research progress on liquid bridge fracture in field of micro-nano technology Zhaofei ZHU Yalong CHU Xianming GAO The Chinese Journal of Process Engineering    2023, 23 (6): 814-825.   DOI: 10.12034/j.issn.1009-606X.222287 Abstract （409）   HTML （16）    PDF （4290KB）（442）       Knowledge map    Save Affected by the scale effect, the morphological characteristics of liquid bridges at the microscale determine the changes in liquid bridge forces that are area-related. Liquid bridge forces have an important impact on the formation and fracture of liquid bridges. The liquid bridge fracture mechanism based on liquid bridge morphology is the theoretical basis of biology, chemistry, materials, micro-nano technology, and many other research fields. At present, the study of liquid bridge fracture is an interdisciplinary discipline involving mathematics, fluid mechanics, interface chemistry, materials science, and other disciplines, however there is few review of the research progress focusing on liquid bridge fracture based on liquid bridge morphology. This review mainly summarizes the fracture theoretical models and experimental methods of axisymmetric liquid bridges, non-axisymmetric liquid bridges, and non-Newtonian liquid bridges. It mainly introduces the weak nonlinear behavior of the fluid generated during the tensile and rupture of the liquid bridge under equilibrium or steady state caused by the forced hydraulic bridge. The influences of key factors such as liquid volume, viscosity, surface tension, wettability, roughness of the solid surface, fracture speed, and liquid bridge morphology on the fracture location or liquid distribution rate of the liquid bridge are systematically described. The experimental methods for quantitatively studying the use of different key parameters affecting liquid bridge fracture are analyzed. The structural characteristics of different experimental apparatus and their advantages and disadvantages are compared and discussed. Furthermore, the innovative and high-value research direction of the research is summarized and proposed, which may be used in future research. Finally, the research frontier trends of liquid bridge fracture in the field of micro-nano technology prospected, and it is pointed out that the future research focused on issues including a more comprehensive hydraulic bridge fracture model, the fracture mechanism, and multi-parameter control method of the liquid bridge. Related Articles | Metrics

Select

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 （1017）   HTML （44）    PDF （13593KB）（428）       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

Select

Gas-liquid flow simulation of a distillation tray based on OpenFOAM Xiaoqing ZHOU Yunpeng JIAO Tianbo FAN Xianfeng HE Jianhua CHEN The Chinese Journal of Process Engineering    2023, 23 (6): 858-869.   DOI: 10.12034/j.issn.1009-606X.222258 Abstract （398）   HTML （13）    PDF （8891KB）（424）       Knowledge map    Save Distillation column with sieve tray is an important separation equipment and widely used in the process industry. The complex behavior of the gas-liquid two-phase flow in distillation columns, especially on the tray, significantly affects the separation performance. With increasing applications of the CFD simulation in multiphase flow, it is interesting to adopt the CFD tools in distillation design and optimization. Traditionally, commercial CFD software has been applied in this field, while they face the problems of black-box feature, limited and expensive license, inflexibility of developing tailored models, etc. Therefore, this work turns to the open source platform of OpenFOAM. By using the Eulerian solver in OpenFOAM, an experimental sieve tray column is studied. The two-phase flow characteristics under different operating conditions are explored, including the height of the clear liquid layer, the gas and liquid velocity, the pressure drop, etc. The predicted trends are consistent with the experimental results. The simulated clear liquid height decreases with increasing gas flow rate and increases with liquid flow rate, and its deviation from the experiments is attributed to the empirical drag correlations which need further study. The influences of sieve holes and liquid inlet conditions on the liquid velocity distribution have been studied. It is found that the number of sieve holes has little impact, and simulations with non-uniform liquid inlet conditions agree with the experiments better. This study verifies the feasibility of using OpenFOAM to simulate distillation columns. The next step is to apply the mesoscale approach to gas-liquid crossing flow systems, construct a new interphase drag model to improve the accuracy of the simulation, and consider the influence of heat and mass transfer on the flow field. This work lays a foundation for the next-step coupling simulations, which is promising for the design and optimization of distillation columns. Related Articles | Metrics

Select

Research progress in the preparation of porous biomass carbon materials and their applications in supercapacitors Xuemin ZHANG Guanyu HE Shaoqi YIN Tingting HUANG Jinping LI Jian ZHENG The Chinese Journal of Process Engineering    2024, 24 (2): 127-138.   DOI: 10.12034/j.issn.1009-606X.223036 Abstract （504）   HTML （42）    PDF （1013KB）（404）       Knowledge map    Save The biomass carbon material is a kind of green and renewable energy material. Its efficient utilization is of great significance for the sustainable development of the energy environment and the green and low-carbon transition of energy. Biomass carbon materials are widely used in energy storage and conversion, catalysis, adsorption, and many other fields due to their porous nature, abundant functional groups, large specific surface area, excellent electrochemical performance, low cost, and renewable. However, the properties of biomass carbon materials are not only closely related to the microstructure, but also the heteroatom doping has an important impact on the structure and electrochemical properties of biomass carbon materials. The accurate structure regulation of biomass carbon materials is an effective way to improve their electrochemical performance. In this work, the preparation methods of biomass carbon materials and their applications in supercapacitors are comprehensively reviewed, and the relationship between the structure and properties of porous carbon materials is discussed. On this basis, the influence mechanism and rules of different conditions, and different preparation processes (such as material selection, material treatment, and activation mode) on the structure characteristics of biomass carbon materials are analyzed. In this review, the mechanism and rules of the influence of the structure characteristics on the electrochemical properties of porous biomass carbon materials are described in detail, and the preparation process and performance regulation of porous biomass carbon materials need to be perfected and improved. Finally, the main development directions of preparation technology and electrochemical properties of porous biomass carbon materials in the future are pointed out. Related Articles | Metrics

Select

Research progress of lithium polysulfide capture in lithium-sulfur batteries Tingting HU Haijian LIU Yunyi CHEN Lingli LIU Chun'ai DAI Yongsheng HAN The Chinese Journal of Process Engineering    2023, 23 (9): 1231-1243.   DOI: 10.12034/j.issn.1009-606X.222413 Abstract （415）   HTML （26）    PDF （6063KB）（386）       Knowledge map    Save Lithium-sulfur battery has an ultra-high theoretical specific capacity (1675 mAh/g) and theoretical specific energy (2600 Wh/kg), which is far higher than commercial secondary batteries. In addition, the sulfur element is rich in the earth, and its price is cheap, the extraction process is environmentally friendly. Therefore, a lithium-sulfur battery is considered as an ideal energy storage unit for the future energy storage system. However, the lithium polysulfide intermediates generated in the charging and discharging process are easily soluble in the electrolyte, resulting in a loss of active materials and an increase in the electrolyte viscosity. In addition, the dissolved lithium polysulfide is inclined to migrate between positive and negative electrodes, and reacts with the lithium negative electrode, causing irreversible loss of active substance sulfur, greatly reducing the battery life and safety. This phenomenon is called the shuttle effect, which hinders the commercialization process of lithium-sulfur batteries. In recent years, researchers have attempted to solve this problem through physical adsorption, chemical action, and external field constraint, and achieved impressive progress. This work summarizes the research progress of capturing lithium polysulfide, and compares the characteristics of each approach and its impact on the electrochemical performance of lithium-sulfur batteries. Whether it is the physical constraint of the porous structure of carbon materials, the chemical interaction between the carrier materials and lithium polysulfide, or the adsorption of electric and magnetic fields on lithium polysulfide, lithium polysulfide is fixed on the positive side and to inhibit its dissolution and diffusion to the negative electrode. Capturing lithium polysulfide by external magnetic field, internal magnetic field induced by magnetic particles, and internal electric field generated by spontaneous polarization of ferroelectric materials is also highlighted. Finally, the challenges in capturing lithium polysulfide and the possible solution are prospected. Related Articles | Metrics

Select

Theoretical design of new energy solid-state battery materials and development of battery technology under the background of carbon peaking and carbon neutrality Hongjie XU Guanghui WANG Yujie SU Zhigao ZHANG Haitong LI Zhongzheng YANG Yuchen WANG Linyue HU Guoqin CAO The Chinese Journal of Process Engineering    2023, 23 (7): 943-957.   DOI: 10.12034/j.issn.1009-606X.223113 Abstract （477）   HTML （14）    PDF （4779KB）（342）       Knowledge map    Save Rechargeable lithium metal batteries (LMBs) have attracted wide attention due to their high theoretical energy density and important applications in portable electronic devices, electric vehicles, and smart grids. However, the implementation of LMBs in practice still faces many challenges, such as low Coulombic efficiency, poor cycle performance, and complex interfacial reactions. An in-depth analysis of the physical basis and chemical science of solid-state batteries is of great significance for battery development. To confirm and supplement the experimental research mechanism, theoretical calculation provides strong support for exploring the thermodynamic and kinetic behavior of battery materials and their interfaces and lays a theoretical foundation for designing batteries with better comprehensive performance. In this review, the theoretical and structural design ideas of the Li10GeP2S12 system and argyrodite system in sulfide solid electrolytes are reviewed, including the transport mechanism and diffusion path of lithium ions. The theoretical design ideas of new anti-perovskite Li3OCl and double anti-perovskite Li6OSI2 electrolyte systems are analyzed. The transport mechanism of Li+ in oxide solid electrolyte systems under defect regulation is reviewed. In addition, the theoretical design of new halide electrolyte systems, and the role of computational materials science in the study of battery material properties are also introduced. The key issues such as ion transport mechanism, phase stability, voltage platform, chemical and electrochemical stability, the interface buffer layer, and electrode/electrolyte interface are analyzed by theoretical methods. Understanding the charge-discharge mechanism at the atomic scale and providing reasonable design strategies for electrode materials and electrolytes. Related Articles | Metrics

Select

Large eddy simulation for single particle wake characteristics in concave-wall tangential jet Jing ZHANG Wenhao HOU Chenghao ZHOU Zhiguo TIAN Bin GONG The Chinese Journal of Process Engineering    2023, 23 (11): 1497-1505.   DOI: 10.12034/j.issn.1009-606X.223019 Abstract （259）   HTML （4）    PDF （6139KB）（331）       Knowledge map    Save Large eddy simulation was used to simulate the influence of spherical particles near the wall on fluid flow characteristics under the action of tangential jets on the concave-wall. The simulated wake vortex results were in good agreement with the experimental tracer image. The vortex structure and its evolution process of particle wake with particle diameter dp=4 mm and radius of curvature of concave wall R=200 mm were studied. The changes of velocity, vorticity, and streamline around the particle were investigated at Reynolds number Re=700~10 000. The results showed that the vorticity in the influence area of particles increased, the peak value of vorticity always appeared on the upstream surface of particles, and the recirculation zone behind the particles shrank significantly with the increase of Reynolds number. When Re=700, there was only one wake vortex behind the particle along the concave wall jet spanwise. When Re≥2000, there were two wake vortices behind particles along the concave wall jet spanwise, and the tangential velocity and vorticity of the fluid fluctuated periodically. The particle lift and resistance were monitored. There was the vortex shedding frequency at Strouhal number St=0.000 854 when Re=2000, and the peak value of the lift power spectrum occurred at St=0.001 52. The frequency peak corresponding to the boundary layer and wake instability was not found in the drag power spectrum when Re=10 000, and the peak of the lift power spectrum occurred at St=0.008 74. The particle wake had a great influence on the flow field. The analysis of the particle wake characteristics in the tangential jet on the concave wall was an in-depth study of the liquid-solid two phase separation mechanism. It provided the theory for the characteristics of single particle wake vortex in the process of heterogeneous separation of the tangential jet from concave wall. Related Articles | Metrics

Select

Preparation of nano-calcium carbonate intensified by CO2 micro bubble and transfer-reaction analysis Liheng WANG Xiaoping GUAN Ning YANG Zuze MU The Chinese Journal of Process Engineering    2023, 23 (9): 1313-1324.   DOI: 10.12034/j.issn.1009-606X.222450 Abstract （500）   HTML （7）    PDF （2491KB）（330）       Knowledge map    Save Carbonization is one of the common methods to prepare nano calcium carbonate. Controlling the particle size and particle size distribution of calcium carbonate is the key to the preparation of high-quality nano-calcium carbonate by carbonization. Different operating conditions have different effects on the reaction products. The particle size and size distribution of calcium carbonate can be effectively controlled by controlling different reaction conditions to improve the mass transfer and reaction conditions in the slurry. In batch-operated bubble column reactor, gas flow rate and bubble size are factors affecting mass transfer. This study investigates the influences of operation condition (gas flow rate, initial slurry condition), bubble type (ordinary bubble, micro bubble) on carbonation reaction rate and particle size distribution of calcium carbonate. Furthermore, the effects of bubble type on the stable region and abrupt change region in carbonation reaction process are analyzed. The experimental results show that when using ordinary bubble, the increase of CO2 flow rate accelerates the reaction process and reduces the particle size of calcium carbonate, but it does not affect the time of abrupt change region. With increasing the slurry concentration, the particle size first decreases and then increases in small-diameter column with ordinary bubble. However, when using micro bubble, the particle size of calcium carbonate is significantly reduced, and the time of abrupt change region decreases with the increase of gas flow rate. Moreover, the CO2 flow rate is no longer an influential factor on calcium carbonate particle size, which means that the gas-liquid mass transfer process is not the rate controlling step of carbonation reaction. This study provides some references for studying the application of micro bubbles in calcium carbonate crystallization. Related Articles | Metrics

Select

Progress on resource utilization and second utilization of chloride removal products from Friedel's salt precipitation method Yun GU Peng CHU Dongdong GE Shouqiang HUANG Min JIANG Hongying LÜ Wenxin ZHANG Yangyang LÜ Yang LÜ Yaheng ZHANG The Chinese Journal of Process Engineering    2024, 24 (2): 151-161.   DOI: 10.12034/j.issn.1009-606X.223122 Abstract （513）   HTML （15）    PDF （1474KB）（322）       Knowledge map    Save The high concentration of Cl- in wastewater can seriously corrode industrial equipment, and also pollute the water environment. A series of technologies for removing Cl- from wastewater have been reported, such as membrane separation, concentration, evaporation crystallization, chemical precipitation, adsorption, ion exchange, electrolysis, oxidation, and solvent extraction. Among them, chemical precipitation has significant advantages in equipment investment and operability, Friedel's salt precipitation method of Cl- removal has been intensively studied because of the wide source and low price of raw materials, compared with other methods using silver, copper, or bismuth. After the Cl- removal, a large quantity of chemical sludge is produced, which mainly contains Friedel's salt (3CaO?Al2O3?CaCl2?10H2O), katoite [Ca3Al2(OH)12], and calcium hydroxide, etc. Due to the complex components and the tight binding of Cl- in the interlayer spacing of Friedel's salt, the resultant sludge is difficult to recycle. To promote the application of Friedel's salt precipitation method, it is very important to utilize its Cl- removal products, especially Friedel's salt, as a resource. Based on the introduction of the compositional and structural characteristics of Friedel's salt, this work highlights the advantages of Friedel's salt precipitation method, which cannot only remove Cl-, but also obtain Friedel's salt, by comparing other preparation methods. According to the aluminum and calcium components of Friedel's salt and its layered bimetallic hydroxide structure, effective resource utilization can be carried out, including the removal of various heavy metal cations (i.e., Cu2+, Cd2+, Co2+, Zn2+, and Pb2+) and oxygenated anion complexes [i.e., Sb(OH)6-, AsO43-, SeO42-, and CrO42-], and the preparation of polyaluminum chloride coagulants and as sludge dewatering regulators, etc. These uses have broad application prospects, providing reference and exploration direction for the further development of Friedel's salt precipitation method. Related Articles | Metrics

Select

Forced oxidation of calcium sulfite and the influence of impurities in wet desulfurization by calcium carbide slag Yuewu ZHENG Ziheng MENG Lingxian LIAN Jiliang HAN Liwen ZHAO Xingguo WANG Gang XING Ganyu ZHU Huiquan LI The Chinese Journal of Process Engineering    2023, 23 (12): 1725-1738.   DOI: 10.12034/j.issn.1009-606X.223048 Abstract （346）   HTML （5）    PDF （9117KB）（296）       Knowledge map    Save The main component of calcium carbide slag (CCS) is calcium hydroxide [Ca(OH)2], which can replace limestone ore for wet flue gas desulfurization, but the desulfurization byproducts of calcium sulfite particles are small because of the strong alkalinity of CCS, which may affect the oxidation of calcium sulfite and the crystallization of calcium sulfate (CaSO4). The effects of different process conditions on particle size, oxidation rate, water content, and microcosmic appearance in the process of calcium sulfate oxidation and gypsum crystallization were systematically investigated, and the optimal process condition (calcium sulfate content of 5 g/L, aeration rate of 400 mL/min, initial pH value of 5.5, reaction temperature of 40℃, and reaction time of 4 h) was obtained. The byproduct of desulfurization gypsum (mainly calcium sulfate dihydrate) with large particle size, low water content, high purity, and uniform appearance was obtained under the optimal condition, which is conducive to the subsequent resource utilization of desulfurization gypsum. The leaching sequence of each element in the CCS under the actual operating pH conditions of the CCS slurry (acidic conditions) is Na>Ca>Mg>Si>Fe>Al. The effects of impurities of Na, Mg, Si, Fe, and Al in the CCS on the oxidation process of calcium sulfate and the crystallization of calcium sulfate were investigated under the above optimal reaction condition. The results indicated that Mg, Si, and Fe in the CCS had a significant promotion effect on the oxidation rate of calcium sulfate, while Al and Na in the CCS inhibited the oxidation of calcium sulfate. At the same time, the addition of Si impurity had almost no effect on the crystallization of calcium sulfate, the addition of the impurities of Mg, Fe, and Na had less effect on the crystallization of calcium sulfate, and the addition of Al impurity had a significant adverse effect on the crystallization of calcium sulfate. In this study, the CCS-based calcium sulfate was used as the raw material, and the study of calcium sulfate oxidation and gypsum crystallization was carried out, providing theoretical guidance for the forced oxidation process in the actual industrial desulfurization. Related Articles | Metrics

Select

Cover and Contents The Chinese Journal of Process Engineering    2023, 23 (9): 0-.   Abstract （121）      PDF （4613KB）（268）       Knowledge map    Save Related Articles | Metrics

Select

Research progress on preparation of magnetic activated carbon and its application in water treatment Qianyu WANG Yuming ZHANG Yanbin CUI The Chinese Journal of Process Engineering    2024, 24 (3): 259-272.   DOI: 10.12034/j.issn.1009-606X.223228 Abstract （376）   HTML （21）    PDF （2257KB）（268）       Knowledge map    Save Activated carbon (AC) has the characteristics of high specific surface area, porosity, abundant surface functional groups and chemical stability, and these advantages make it a widely used adsorbent in water treatment. After being exhausted (saturated adsorption contaminants), the spent AC needs to be separated from aquatic systems and regenerated which is conductive to materials recycling. However, it is difficult to efficiently separate the powder AC saturated adsorption contaminants from aquatic systems by traditional separation methods (gravitational sedimentation, centrifugation, filtration, and flotation), and the disadvantages for these methods root in many aspects including time-consuming, high-cost, and low separation efficiency. These limit the wide application of activated carbon in the field of water treatment to some extent. Magnetic modification treatment on AC can provide a magnetic activated carbon (MAC) which possesses better performances reflecting in higher adsorption capacity, and can be easier, rapid and efficient separation through external magnetic fields. At the same time, MAC has good catalytic activity, which is useful for enhancing the capability of advanced oxidation process to efficiently degrade organic pollutants in aquatic systems. Therefore, MAC has broad application prospects in the field of water treatment. This work mainly introduces the preparation methods (co-precipitation method, thermochemical method, and mechanical milling method), microstructure and physicochemical properties (specific surface area, pore structure, magnetism, crystal and chemical structure, surface charge) of MAC. The research progress of MAC in wastewater treatment in recent years is reviewed, consisting of organic pollutant removal, heavy metal removal and other applications. The adsorption characteristics (adsorption isotherms and adsorption dynamics) and corresponding influencing factors (adsorption temperature, solution pH, and coexisting ions) are summarized in details. And the regeneration methods of AC are investigated comprehensively. In the end, the development and prospect of the application of MAC in water treatment are also discussed. Related Articles | Metrics

Select

Experiment and DEM numerical simulation of mixing power of ultrafine powder based on similarity theory Hui CHEN Xuedong LIU Wenming LIU Weiwen ZHENG Honghong ZHANG Kaixin LÜ The Chinese Journal of Process Engineering    2023, 23 (11): 1506-1517.   DOI: 10.12034/j.issn.1009-606X.222421 Abstract （280）   HTML （5）    PDF （2454KB）（264）       Knowledge map    Save In order to study the correlation between the stirring power characteristics of ultrafine powder and the operating parameters and the calculation expression of stirring power, the problems of difficult calculation and lengthy calculation time in ultrafine powder stirring simulation were solved. The method of combining experimental research and numerical simulation was used to study the variation law of stirring power and torque of the ultrafine powder mixing process in the mechanical powder mixer. The stirring experiment of light calcium carbonate powder with an average particle size of 10.56 μm was carried out, and the operating parameters in the mechanical powder mixer, including the effects of rotational speed, blade position, and material surface height on the stirring power and torque of ultrafine powder were studied, and the expression of power calculation was obtained. Using the similar principle, the fine particles of the powder were enlarged, and the virtual experiments were carried out on the enlarged coarse particles to obtain the contact parameters. The DEM numerical simulation of the coarse particle stirring process was carried out, and the results of the simulated stirring power and torque were compared with the experimental results. The results showed that the mixing power consumption of ultrafine powder in the mechanical powder mixer was closely related to the parameters of the rotational speed, blade position, material surface height and so on. At the same time, the torque value and power value were positively correlated with rotational speed and material surface height, and negatively correlated with the blade position. The ratios of simulated torque value and power value to experimental torque value and power value were basically consistent with the particle amplification factor, which verified the accuracy of the similar principle applied to study the influence of blade position and material surface height on the stirring power characteristics. Related Articles | Metrics

Select

A review on current status and carbon accounting of recycling and reusing of spent power batteries Zhiying LAI Wenbin LAI Chuyuan LIN Lingjun HE Hui LIN Fuyu XIAO Qingrong QIAN Jixiang ZHANG Qinghua CHEN Lingxing ZENG The Chinese Journal of Process Engineering    2024, 24 (2): 139-150.   DOI: 10.12034/j.issn.1009-606X.223195 Abstract （449）   HTML （13）    PDF （3821KB）（264）       Knowledge map    Save The booming development of the new energy vehicle industry has ed a significant rise in the amount of end-of-life power batteries, which in turn generates a huge amount of solid waste. Reuse of retired power batteries through laddering utilization and recycling can not only realize the resourceful reuse of valuable metals but also reduce carbon emissions and production costs. As an important part of developing the circular economy and promoting the intensive use of resources, the recycling and the resource utilization of power batteries are of great significance to the implementation of the carbon peaking and carbon neutrality strategy and the promotion of the construction of ecological civilization. Currently, a substantial body of literature and information pertaining to retired batteries has been extensively disseminated across the pertinent domains. Consequently, it is imperative to consolidate the pivotal insights within the industry to furnish industry professionals with a comprehensive point of reference. Overall, based on the current situation of the industry, the main purpose of this review is to discuss the environmental and economic impacts of the different recycling and reusing methods for retired batteries from the perspectives of the recycling process. By analyzing the current situation of recycling and summarizing the progress of research, an accounting method for carbon emissions from decommissioned power batteries is proposed, and then it is pointed out the necessity and feasibility of recycling. The aim of this review is to provide new insights into building waste-free cities and achieving carbon peaking and carbon neutrality target. It is hoped that the battery recycling industry will be able to realize healthy and orderly development in the future under the macro-control of the country, combined with efficient and eco-friendly retired battery recycling technology and relevant standards and norms. Related Articles | Metrics

Select

Research process of multivesicular liposomes Xing FAN Hua YUE Xiaojun WANG The Chinese Journal of Process Engineering    2023, 23 (10): 1371-1380.   DOI: 10.12034/j.issn.1009-606X.222431 Abstract （467）   HTML （16）    PDF （2032KB）（259）       Knowledge map    Save Since 1983, multivesicular liposomes (MVLs), as a member of the liposome family, have been of interest in the biomaterials and medical fields. MVLs have multiple aqueous compartments separated by phospholipid bilayers and an internal aqueous phase of up to 90%. They also have the advantages of reducing the number of injections, extending the duration of drug action, and improving patient compliance. So far, most of the MVLs reported in the literature are above 10 μm in size and have made good progress mainly in the encapsulation of analgesic drugs. This review provides an overview of the preparation methods, characterization methods, and drug release mechanisms of MVLs that have been reported in the literature in the last decade. There are relatively several methods for preparing MVLs, including the double emulsification method, spray atomization technique, and electroforming method. Currently, the main characterization methods used for MVLs are optical/fluorescent confocal imaging, scanning electron microscopy imaging, determination of particle size distribution, entrapment efficiency, and determination of zeta potential. Because of the large volume of the internal aqueous phase of MVLs and the high hydrophilic drug encapsulation rate of the internal vesicles, the individual vesicles gradually rupture and the hydrophilic drug gradually gets released during in vitro release, with a three-phase release pattern of sustained release. This review also summarizes the current status of clinical studies and types of commercialized products. At present, the application of MVLs regarding analgesics has reached stages II-IV, and three commercialized formulations have entered the clinic with satisfactory results. Moreover, this review summarizes the current progress in applied research, mainly in the delivery of anticancer drugs, analgesic drugs, and protein peptides. Last but not least, the challenge and prospects regarding small-sized MVLs, diverse biomedical applications, and scale-up strategies are proposed. Related Articles | Metrics

Select

Preparation and electrochemical properties of Li0.98Ca0.02Mn2O4 Mingsi SHEN Haibo YUAN Doudou ZHANG Jing WANG Gaotian NIU Yangzhou MA Yaxin SUN The Chinese Journal of Process Engineering    2024, 24 (6): 746-752.   DOI: 10.12034/j.issn.1009-606X.223075 Abstract （167）   HTML （7）    PDF （3274KB）（258）       Knowledge map    Save Many research focus on improving the electrochemical properties of LiMn2O4 by chemical doping method. In cubic spinel structure LiMn2O4, the diversity of doping elements and doping positions provides a wide space for improving performance. Doping at the 16d octahedral position occupied by Mn can effectively suppress the Jahn-Teller effect and maintain the stability of the structure. By comparison, using elements with large ion radius to dope at the 8a tetragonal position occupied by Li can enlarge the Li+ diffusion channel and enhance the kinetics diffusion coefficient. In this work, pure phase of Li0.98Ca0.02Mn2O4 was successfully synthesized using the hydrothermal method followed by annealing at 750℃ for 5 h. The crystal structures and the morphologies of the products were analyzed by powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The electrochemical properties were characterized by galvanostatic charge/discharge experiments and electrochemical impedance spectroscope (EIS) tests. XRD analysis showed that the lattice constant increased by 0.12% in Ca-doped LiMn2O4 and the expansion of the crystal cell was beneficial to improving the diffusion of Li+. The small aggregates with porous channels formed by stacking nanoparticles were observed by FESEM. The results showed that Li0.98Ca0.02Mn2O4 exhibited the excellent rate capability with the larger discharge capacity at the relatively current rate range of 0.5 C~5 C. Especially, at 0.5 C, Li0.98Ca0.02Mn2O4 delivered the first discharge capacity of 126 mAh/g, which was 17.8% higher than that of undoped LiMn2O4 samples. The capacity retention of both samples was maintained at about 88.8% after 50 cycles. At 1 C, Li0.98Ca0.02Mn2O4 still holded its high discharge capacity of 117.5 mAh/g and capacity retention of 90% after 50 cycles, 80% after 150 cycles, and 60% after 1000 cycles. Undoped LiMn2O4 sample had low capacity of 57.0 mAh/g, but the capacity retention reacheed 67% after 1000 cycles, indicating good cycle stability. The calculated kinetics diffusion coefficient of Li0.98Ca0.02Mn2O4 was 2.5×10-11 cm2/s, which was about 1.6 times of undoped sample. Related Articles | Metrics

Select

Numerical simulation of blending effectiveness of forcing mixer based on EDEM Xu GAO Jie LEI Zhanxia DI Shanping LIU Yunfeng SONG Hongming LONG The Chinese Journal of Process Engineering    2023, 23 (11): 1530-1540.   DOI: 10.12034/j.issn.1009-606X.222459 Abstract （278）   HTML （8）    PDF （36544KB）（257）       Knowledge map    Save The mixing effect of raw materials is an important factor affecting the quality and production efficiency of pellets. The forcing mixer is the core mixing equipment, and the appropriate operating parameters can make the mixed materials achieve the best mixing effect. In industry, the basic performance indicators of pellets are generally used to replace the mixing effect of materials, such as falling strength and compressive strength, resulting in long detection process, large error, and inability to visually obtain material trajectory and dispersion effect. In this study, SOLIDWORKS software is used to establish a forcing mixer model, and EDEM discrete element software is used to simulate the movement behavior of materials in the reactor. The effects of the rotating motion of the rotor, the bottom and the wall of the mixer and the filling rate of the materials on the mixing effect are studied. The results show that increasing the rotor speed can significantly improve the mixing effect, but when the rotation speed reaches ±48 r/min, the improvement of the mixing effect is not obvious. The rotation of the bottom can break through the speed threshold of the double rotor rotation, and the bottom can greatly improve the mixing effect at a lower rotation speed of +30 r/min. On the contrary, the rotation of the wall produces a stacking effect, which inhibits the dispersion of the particles, thereby reducing the mixing effect. The high filling rate is not conducive to the dispersion of materials above the rotor blade position, and the mixing effect is the best when the filling rate is 60%. Considering the enterprise pellet production and mixing equipment running performance requirements, the reasonable operating parameters are rotor rotation speed of ±30 r/min, the bottom rotation speed of +30 r/min, the wall rotation speed of 0 r/min, and filling rate of 60%. Related Articles | Metrics

Select

Surface modification and catalytic performance study of Cu-based carbon dioxide to methanol hydrogenation catalyst Qiang YANG Gang WANG Chunshan LI The Chinese Journal of Process Engineering    2024, 24 (10): 1166-1176.   DOI: 10.12034/j.issn.1009-606X.224059 Abstract （449）   HTML （17）    PDF （3618KB）（254）       Knowledge map    Save Development of effective copper-based catalyst for CO2 hydrogenation to methanol is of great significance, considering the utilization of this greenhouse gas. In this work, a series of surface promoter-modified (Mn, In, Mo, Mg, Zr) catalyst were synthesized by coprecipitation-post impregnation method and evaluated for CO2 hydrogenation to methanol in fixed-bed reactor. The role of metal modifier on the physicochemical properties of Cu/ZnO/Al2O3 (CZA) were investigated through CO2-TPD, XRD, XPS and H2-TPR. In addition, the catalytic mechanism for CO2-to-methanol hydrogenation was revealed by employing in situ IR. The results showed that the Mn-modified CZA with good reduction behavior, excellent CO2 adsorption capacity and suitable Cu+/Cu0 ratio exhibited the best performance. The metal element loaded on catalyst strengthened the interactions between the copper and support, suppressing the growth of Cu. The appropriate Cu+/Cu0 ratio facilitates the stabilization and conversion of methoxy, resulting in increased methanol production. Compared to the untreated CZA catalyst, the Mn-modified catalyst has more medium strong base sites on the surface, which helps to adsorb more CO2 for further hydrogenation to form formate, methoxyl and other intermediates. The incorporation of metal component in CZA facilitated the catalyst reduction ability. The catalytic mechanism follows the formate pathway and the methoxyl species is the crucial intermediate. The Cu nanoparticles on the catalyst surface showed an increased capacity for H2 dissociation when using Mn-modified CZA catalysts. This is due to stronger metal-carrier interactions. The presence of interstitial H in the carriers contributed to the generation of formate species. The dissociated H atoms from the surface Cu nanoparticles replenished the consumed interstitial H. The modified catalyst's interstitial H presence and enhanced H2 dissociation ability accelerated the formation and conversion of intermediate species, promoting methanol generation. Related Articles | Metrics

Select

Metabolic engineering of Escherichia coli to produce glutaric acid Zhilan ZHANG Cong GAO Liang GUO Xiulai CHEN Wanqing WEI Jing WU Wei SONG Liming LIU The Chinese Journal of Process Engineering    2023, 23 (9): 1340-1350.   DOI: 10.12034/j.issn.1009-606X.222453 Abstract （294）   HTML （9）    PDF （2028KB）（242）       Knowledge map    Save Glutaric acid is an important intermediate, which is widely used in chemical industry, agriculture, medicine and other fields. At present, there are some problems in the biosynthesis pathway of glutaric acid, such as long synthesis path, high consumption of cofactors and low yield. In order to develop an efficient method for the synthesis of glutaric acid, a new way to produce glutaric acid using glucose as substrate was constructed by combining enzyme engineering with metabolic engineering. Firstly, a novel catalytic pathway composed of lysine α-oxidase (LO), monoamine oxidase (MAO), α-ketoacid decarboxylase (KDC) and aldehyde dehydrogenase (ALDH) was designed by database mining. AB initio synthesis of glutaric acid was realized by introducing lysine producing strain E. coli CCTCC M2019435. In order to further improve the synthesis efficiency of this pathway, rational analysis and protein modification were carried out for the rate-limiting enzyme KpALDH of the pathway, and the catalytic efficiency of the enzyme was increased by 66.5 times. On this basis, the yield of glutaric acid was increased by 2.0 times through metabolic engineering to enhance the expression of rate-limiting enzyme KpALDH and block the by-product acetic acid metabolic branch. Finally, the glutaric acid fermentation conditions were optimized, the glutaric acid yield increased to 62.0 g/L at the end of fermentation, and the production intensity and yield reached 1.6 (g/L)/h and 0.3 g/g glucose, respectively. Related Articles | Metrics

Select

Recent progress of heterogeneous catalysts towards selective catalytic reduction of NO by CO under oxygen-rich conditions Yaqi LIU Yan LIU Ke WU Liwen XING Dianxing LIAN Mohaoyang CHEN Jianjun JI Yongjun JI The Chinese Journal of Process Engineering    2024, 24 (3): 284-296.   DOI: 10.12034/j.issn.1009-606X.223136 Abstract （357）   HTML （9）    PDF （3784KB）（241）       Knowledge map    Save Nitrogen oxides (NOx), as one of the predominant atmospheric pollutants mainly derived from automobile exhaust and industrial waste gas, have played the role of an inevitable precursor that led to acid rain, photochemical smog, and other environmental contamination issues. In addition to atmospheric pollution, the growing emissions of NOx pollutants also give rise to a serious threat to agricultural production and human health. Thus, it is of urgent need to develop feasible NOx abatement strategies. Selective catalytic reduction of NO by CO (CO-SCR) is a very promising denitrification technology that can simultaneously remove harmful gases of NO and CO, making it one of the most ideal solutions for flue gas treatment. To promote its industrial applications, CO-SCR should have a low operating temperature ranging from 150℃ to 250℃ and superior resistance to oxygen poison. Therefore, there is an urgent need to develop efficient CO-SCR catalysts used under oxygen-rich conditions for abating severe environmental pollution problems. This work provides a comprehensive review of the research progress and latest research findings of CO-SCR under oxygen-containing conditions. The research advances of Pd, Ir, Rh, Mn, and Co-based heterogeneous catalysts were introduced, and the effects of active components, promoters, and supports on the catalytic performance of CO-SCR are described in detail. In this section, the preparation method, doping modification, and reaction conditions are analyzed. Meanwhile, the impact of O2, H2O, and SO2 on the catalytic activity of CO-SCR is discussed, in which the inhibition mechanism of O2 is summarized. Finally, the challenges and future developments of CO-SCR under oxygen-rich conditions are summarized and the corresponding coping solutions are proposed. We hope this review can provide an in-depth understanding and useful guidance for the rational design of efficient heterogeneous catalysts for the CO-SCR reaction in practical applications. Related Articles | Metrics

Select

Heat and mass transfer simulation of gas-liquid two-phase flow in a distillation column based on OpenFOAM Yunpeng JIAO Xiaoqing ZHOU Jianhua CHEN The Chinese Journal of Process Engineering    2024, 24 (4): 391-402.   DOI: 10.12034/j.issn.1009-606X.223180 Abstract （430）   HTML （12）    PDF （4117KB）（240）       Knowledge map    Save For multiphase mass transfer processes in distillation columns, computational fluid dynamics can be used not only to simulate the flow phenomena, but also to study the heat and mass transfer processes and their interactions with the flow. Based on previous work on gas-liquid flow simulation in distillation trays, this work applied the multiphase flow solver of the OpenFOAM platform. The energy and species transport equations were considered to construct the heat and mass transfer models for the distillation system. The ideal system of cyclohexane-n-heptane and the non-ideal system of ethanol-water distillation were simulated respectively. The distribution of the gas-liquid two-phase flow, component and temperature on the column trays were analyzed. For the ideal system, the ideal solution mass transfer model can provide accurate predictions for the temperature and concentration fields on the trays. However, for non-ideal systems, it was necessary to introduce the activity coefficient model on the basis of the ideal model. To this end, the effects of two activity coefficient models, UNIQUAC and NRTL, were introduced and compared. In the current simulation framework, the activity coefficient models were able to improve the simulation accuracy of temperature and concentration field. The overall trends predicted by the two models were generally consistent with the results in the literature, and the UNIQUAC model agreed better with the literature. In addition, the comparative analysis of gas-liquid two-phase flow field and concentration field distribution showed that the circulating flow of liquid phase can enhance the local mass transfer efficiency of the column tray, resulting in higher efficiency at the liquid inlet and the weir than the tray center. However, the gas-liquid renewal in the circulating region renewed ly, which led to a reduction in the overall mass transfer efficiency of the column tray. This study can be used for the design and optimization of distillation columns, and it is also valuable for simulations of heat and mass transfer in other gas-liquid two-phase flow systems. Related Articles | Metrics

Select

Numerical simulation on influencing factors of pulverized coal combustion in rotary kiln Yanpeng WANG Yilun LIU Heping LI Mingfei LI Xiuzhen GUO Sichao ZHANG The Chinese Journal of Process Engineering    2023, 23 (11): 1587-1598.   DOI: 10.12034/j.issn.1009-606X.222400 Abstract （255）   HTML （1）    PDF （9523KB）（235）       Knowledge map    Save Rotary kiln is a high-energy consumption equipment widely used in metallurgy, chemical industry, environmental protection and other fields. As the main energy source of the thermal process of the rotary kiln, the efficiency of fuel combustion is directly related to the energy-saving operation of the rotary kiln. In order to improve the pulverized coal combustion efficiency in the rotary kiln, the pulverized coal combustion process in the rotary kiln was numerically simulated by ANSYS Fluent 19.0 software. By controlling a single variable and designing a multi index orthogonal test condition, the influence and significance of air excess coefficient, pulverized coal particle size, swirl angle, ratio between internal and external air volume on the pulverized coal combustion in the rotary kiln were analyzed. The influence rules of each factor on pulverized coal combustion and optimal working condition were obtained. The results showed that the increase of air excess coefficient and pulverized coal particle size increased the flame length, reduced the flame diameter and make the flame slender. The increase of swirl angle shortened and thickened the flame shape. With the increase of the ratio of internal and external air volume, the flame length first increased and then decreased, and the flame diameter first decreased and then increased. The four factors ranking in a decreasing order of in?uence were the pulverized coal particle size, ratio between internal and external air volume, air excess coefficient, and swirl angle. The optimal operating parameter combination of pulverized coal combustion in rotary kiln were air excess coefficient of 1.1, pulverized coal particle size of 40 μm, swirl angle of 25°, ratio of internal and external air volume of 0.9. Compared with the original working condition, the flame length and flame diameter of the optimized working condition increased respectively by 8.9% and 13.9%. Related Articles | Metrics

Select

Research progress on desulfurization technology for blast furnace gas Xindong WANG Tingyu ZHU Yuran LI The Chinese Journal of Process Engineering    2023, 23 (7): 1003-1012.   DOI: 10.12034/j.issn.1009-606X.222334 Abstract （429）   HTML （18）    PDF （1011KB）（235）       Knowledge map    Save The desulfurization technology for blast furnace gas as a source of emission reduction technology is of great significance to promoting ultra-low emission for the whole process in the iron-steel industry. The sulfur-containing components in the blast furnace gas are mainly organic sulfur, coexisting with other complex components. This work discusses the emission limits of sulfur-containing components in various occurrence forms (SO2, H2S, and S), and analyzes their transformation relationship through the mass balance of sulfur. The bottleneck of desulfurization technology for blast furnace gas is to remove the carbonyl sulfur (COS). The aluminum-based catalyst and carbon-based catalyst used for COS catalytic hydrolysis are analyzed in detail, in which γ-Al2O3 is both a carrier and an active component, and activated carbon has the functions of catalyst and adsorbent. The effect mechanism of the complex components O2, and Cl- on the deactivation of hydrolysis catalyst is further elucidated due to the formation of deposition products. For the gaseous H2S formed after the COS hydrolysis, the two kinds of wet removal technology, mainly including the chemical absorption method and catalytic oxidation method, are compared in the reaction mechanism, desulfurizer and product. The difference among the zinc oxide, iron oxide, and activated carbon adsorbent used in the dry removal technology is also concretely elaborated in the reaction mechanism, sulfur capacity, and temperature adaptability. In view of the integrated adsorption of organic sulfur and inorganic sulfur, molecular sieve adsorbent is briefly described in the selective adsorption principle and regeneration process. The "hydrolysis+wet", "hydrolysis+dry", and integrated removal processes have been explored and applied currently, which are preliminarily evaluated. Finally, it is pointed out that the research and development of desulfurization technology focus on how to improve the activity of the hydrolysis catalyst and reduce the influence of complex components in blast furnace gas on catalyst activity and improve the applicability of the technology. Related Articles | Metrics

Select

Catalytic conversion of the by-product bromoethanol in the process of CO2 cycloaddition Ruibin GAO Lixin YI Zifeng YANG Li DONG Yifan LIU Hongfan GUO Yunong LI The Chinese Journal of Process Engineering    2023, 23 (11): 1518-1529.   DOI: 10.12034/j.issn.1009-606X.222468 Abstract （285）   HTML （0）    PDF （1824KB）（232）       Knowledge map    Save The rapid and massive accumulation of greenhouse gas CO2 in the atmosphere directly leads to global warming, ecological damage, and other environmental problems. From the perspective of renewable carbon resource utilization, CO2 is a widespread, inexpensive, and easily available C1 resource. The synthesis of ethylene carbonate employing CO2 as raw material provides a feasible industrial scheme for CO2 utilization with the atomic economy. The traditional efficient catalyst for this cycloaddition is halogen ionic liquid. However, the loss of halogen ions in the cycloaddition process leads to the additional consumption of epoxide and the generation of halogenated alcohol, thus decreasing the selectivity and yield of the main product, resulting in separation difficulty and improving equipment requirements. Therefore, it is necessary to develop an ideal catalytic system to inhibit and transform the by-product of halogenated alcohols. In this work, a series of alkalescent ionic liquids had been designed and developed to realize the in?situ conversion of bromoethanol under the condition of cycloaddition (temperature of 130℃, CO2 pressure of 3 MPa, reaction time of 3 h). The effects of different reaction conditions and different alkaline ionic liquids on the conversion of bromoethanol were investigated, including ionic liquid type, reaction temperature, different pressure environment, reaction time, etc. The reaction law of bromoethanol conversion was revealed, among which [Bu4P][HCO3] showed optimal performance. Using gas atmosphere and solvent microenvironment to regulate different reaction paths, the conversion rate of bromoethanol reached 20%~50%. After ethylene carbonate (EC) addition, the by-products with bromine-containing covalent bonds were reduced, which was more conducive to the formation of bromine ions. The conversion of halogen covalent bonds to halogen ions restored part of the catalytic activity of the cycloaddition reaction system. This was a simple versatile approach, which can realize the in?situ regulation of bromoethanol conversion pathways in the CO2 cycloaddition system, and promote the optimization of the CO2 utilization system and the circulation of halogen ions, hence possessing important scientific significance and application value. Related Articles | Metrics

Select

Key technologies and advances of positron emission particle tracking Kun LI Liyun WU Ping CHEN Yan HAN The Chinese Journal of Process Engineering    2024, 24 (4): 381-390.   DOI: 10.12034/j.issn.1009-606X.223266 Abstract （400）   HTML （17）    PDF （2513KB）（226）       Knowledge map    Save Measuring multiphase flow parameters and the understanding of multiphase flow mechanisms are of great importance value for the design, operation, and optimization of industrial process devices. Due to the inherent multiscale nature of multiphase flow, its flow field often has great complexity, which makes our understanding of its flow process relatively limited. There are still many key issues that need to be explored in the mechanism of multiphase flow. Positron emission particle tracing (PEPT) is a new undisturbed and non-destructive imaging method for complex multiphase flows in industrial processes. γ photon detection is used to perform 3D dynamic imaging of radioactive labeled tracer particles. Due to γ photons have high penetration and are not affected by electromagnetic fields, making PEPT a unique advantage in detecting non-transparent and complex industrial multiphase flows. Currently, it is mainly used for measuring multiphase flow phenomena and extracting system physical parameters in industrial fields such as chemical, food, and pharmaceutical industries. However, the difficulties in preparing miniaturized tracer particles and the poor localization effect of multiple tracer particles at the same time seriously hinder the further application and promotion of PEPT technology. In this work, basic principles of PEPT technology are firstly briefly introduced, then the key technologies and research progress of PEPT are discussed from the aspects of tracer particles, algorithms, hardware systems and data processing in applications. The existing problems and potential development directions are pointed out. Finally, the development and application of PEPT is summarized and prospected. Related Articles | Metrics