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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 （613）   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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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 （321）   HTML （90）    PDF （47402KB）（336）       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

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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 （328）   HTML （15）    PDF （1140KB）（269）       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

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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 （231）   HTML （7）    PDF （4779KB）（223）       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

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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 （394）   HTML （21）    PDF （13593KB）（207）       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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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 （124）   HTML （4）    PDF （6139KB）（202）       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

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Cover and Contents The Chinese Journal of Process Engineering    2023, 23 (7): 0-.   Abstract （92）      PDF （2307KB）（182）       Knowledge map    Save Related Articles | Metrics

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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 （167）   HTML （17）    PDF （6063KB）（173）       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

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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 （199）   HTML （8）    PDF （4290KB）（159）       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

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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 （172）   HTML （2）    PDF （8891KB）（154）       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

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DEM modeling of resonant motion of particles inside moving bed Qinjian SHEN Shijie DONG Dancheng ZHANG Hui GUO Yinling SONG Xiaoxing LIU The Chinese Journal of Process Engineering    2023, 23 (6): 826-836.   DOI: 10.12034/j.issn.1009-606X.222161 Abstract （158）   HTML （5）    PDF （5476KB）（141）       Knowledge map    Save Moving beds are ubiquitous in various process industries. Thoroughly understanding and accurately characterizing the complex flow behavior of granular materials from the component particle scale is obviously of great significance for the design, scale-up, and optimization of moving beds. In this work, the flow behavior of granular assemblies in moving beds under both the funnel flow and semi-mass flow discharge regimes are investigated by performing three-dimensional discrete element method (DEM) simulations, with a focus on the possible similarities and differences between the fluctuating characteristics and also the corresponding underlying mechanisms of the transient motions of particles under these two discharging conditions. The reliability of the DEM simulation is verified by comparing the predicted evolutions of the boundary of the flowing zone and also its characteristic width with experimental results. The simulation results demonstrate that under both discharge conditions, the temporal variations of the spatially averaged axial velocity of particles in the upper part of the flowing zone present notable non-random fluctuating characteristics, manifested by the appearance of a clear peak in the Fourier spectrum of the time series of spatially averaged particle axial velocity. The spatial correlation analysis results show that the temporal fluctuations of the spatially averaged axial velocity of particles in different axial regions of the upper part of the flowing zone are closely correlated, suggesting the occurrences of resonance under both discharging types. The delayed correlation analyses of the time series of the spatially averaged axial velocities of particles in different axial zones indicate that such resonant behavior originates from a bottom zone right above the outlet. The delayed correlation analyses of the time series of the spatially averaged particle axial velocity and the spatially averaged particle contact force demonstrate that there exists a strong correlation between the temporal fluctuations of these two parameters, and the latter precedes the former, which hints that the observed resonance could be ascribed to the free-fall arch mechanism. In brief, the presented simulation results clearly demonstrate that resonance can occur during both funnel and semi-mass flow discharges and there is no intrinsic difference between the resonant features of particles under these two discharging conditions. Related Articles | Metrics

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Cover and Contents The Chinese Journal of Process Engineering    2023, 23 (9): 0-.   Abstract （69）      PDF （4613KB）（140）       Knowledge map    Save Related Articles | Metrics

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Research status and prospect of key installations and flow characteristics of pneumatic conveying Jiawei ZHOU Xiangyu YAN Zebing ZHENG Qinghui WANG Linjian SHANGGUAN The Chinese Journal of Process Engineering    2023, 23 (5): 649-661.   DOI: 10.12034/j.issn.1009-606X.222192 Abstract （161）   HTML （1065）    PDF （3837KB）（124）       Knowledge map    Save Pneumatic conveying has the characteristics of environmentally friendly, operational safety, spatial intensification, flexible configuration, and easy to automate. In addition, this bulk material handling method also has the advantages of quantitative conveying, conveniently dispersing or centralized conveying, and inert gas protection conveying for unstable materials. The aforementioned characteristics pneumatic conveying to a commonly clean conveying technology for bulk materials. At the same time, pneumatic conveying has been widely applied in chemical, food, pharmaceutical, energy industries, and other fields. However, this method also has a few problems, such as high energy consumption, particle degradation, and pipe erosion. The fundamental cause of the disadvantages lies in the complex conveying process, transient state of particle conveying, and difficulty in accurate prediction. Therefore, the multi-means characterization and prediction of material conveying characteristics in different conveying processes have always been the hot points of this technology. It is well known that the equipment composition is the foundation of pneumatic conveying system performance. In addition, the feeding device is one of the most important factors for conveying processes. In this meaning, this work first summarized the structure of the pneumatic conveying system and the structural characteristics of commonly used feeding devices. Then, this work reviews the application and research of the numerical simulation methods including the two-fluid model in the computational fluid dynamics and the coupling simulation of the computational fluid dynamic discrete element method (CFD-DEM). The application conditions, merits, and demerits of the common numerical method are discussed. What is more, the research and application status of measuring devices commonly used in pneumatic conveying are summarized, including electrical capacitance tomography (ECT), pressure determination, and acoustic emission. Meanwhile, the study mainly focuses on flow pattern evolution and pressure loss in the conveying system, as well as some interesting study points of pneumatic conveying, which are well explored. Finally, several thinking points for future research on this technology are discussed. Related Articles | Metrics

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Catalytic conversion of the by-product bromoethanol in the process of CO 2 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 （129）   HTML （0）    PDF （1824KB）（124）       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

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Numerical study on CO 2 bubble rise process coupled with mass transfer Donghao PEI Lexiang ZENG Mengdie GAO Jincheng RUAN Jun CAO The Chinese Journal of Process Engineering    2023, 23 (9): 1244-1255.   DOI: 10.12034/j.issn.1009-606X.222385 Abstract （150）   HTML （5）    PDF （15818KB）（118）       Knowledge map    Save Gas-liquid two-phase flow and mass transfer phenomena widely exist in nature and daily life. Studying the mass transfer process of bubbles in water is of great significance for understanding the mass transfer mechanism and exploring the enhancement of the mass transfer process. The volume of fluid (VOF) method was used to simulate the rising process of CO2 bubble in still water, and the mass transfer process was considered by a user defined function program. The instantaneous velocity, mass transfer coefficient, CO2 dissolved amount, and mass transfer wake changes of bubbles with different initial diameters during the rising process were studied. In the process of bubble rising, the transverse velocity changed periodically and the oscillation amplitude decreased with the increase of bubble initial diameter, while the longitudinal velocity increased with the increase of the bubble initial diameter. Between 3.5 mm and 6 mm, with the increase of the bubble diameter, the CO2 dissolved amount increased, and the wake stream showed three states: symmetrical state, transitional state, and periodic shedding. The critical Re number of 3.5~6 mm bubble wake transition increased with the increase of bubble initial diameter, the frequency of wake periodic shedding was 17~22 Hz, and the departure frequency decreased with the increase of bubble initial diameter. The bubble wake was consistent with the mass transfer wake. With the increase of the bubble initial diameter, the influence range of the bubble mass transfer wake increased. Related Articles | Metrics

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Efficient catalytic synthesis of cyclic carbonates from carbon dioxide by phosphine-based composite catalysts Heming ZHANG Chan MENG Li DONG Qian SU Weiguo CHENG The Chinese Journal of Process Engineering    2023, 23 (7): 987-994.   DOI: 10.12034/j.issn.1009-606X.223098 Abstract （110）   HTML （3）    PDF （5200KB）（117）       Knowledge map    Save Carbon dioxide (CO2) is both a major contributor to the greenhouse effect and an important C1 resource. The synthesis of cyclic carbonates from CO2 and epoxides is an important way of high efficiency and high value utilization. The development of high efficiency catalyst is the focus of research for this reaction. In the past, there were some problems such as poor stability, low catalytic activity and complex preparation of catalyst. Therefore, the aim of this study was to develop phosphine-based catalysts with high catalytic activity, low price and good stability. In this study, a binary composite catalytic system was formed between phosphine oxide compound and metal salt with high stability. By regulating different proportions of metal salts and phosphine oxide compounds, the binary composite catalytic system with different proportions was formed, and the optimal transition metal salts and the optimal ratio were selected (Bu3PO:ZnBr2=2:1, namely [2Bu3PO-ZnBr2]). The influence of catalyst dosage, CO2 pressure, reaction time, and reaction temperature on propylene oxide (PO) conversion and the selectivity of propylene carbonate (PC) was investigated. The results showed that under optimum reaction conditions (130℃, 3 h, 3 MPa), the PO conversion was 92%, the PC selectivity was 99% and the catalyst maintained high catalytic activity after five cycles. Finally, the interactions between the phosphine-based binary composite catalytic system and the reactants were revealed through relevant characterization, and the Lewis acid co-catalytic mechanism was proposed. The phosphine-based binary composite catalytic system proposed in this study provides a new idea for efficient and inexpensive catalyst utilization. Related Articles | Metrics

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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 （168）   HTML （8）    PDF （1011KB）（116）       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

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Flow characteristics of gas-liquid two-phase flow in microchannel with obstacles Yuanhao HUO Gang YANG Huichen ZHANG The Chinese Journal of Process Engineering    2023, 23 (12): 1617-1626.   DOI: 10.12034/j.issn.1009-606X.222454 Abstract （112）   HTML （9）    PDF （5399KB）（114）       Knowledge map    Save The obstacles in the microchannel have a significant impact on the pressure drop and bubble shape of gas-liquid two-phase flow. In this work, experimental and numerical simulation methods are used to explore the effect of obstacles in the channel on the movement characteristics of nitrogen/water gas-liquid two-phase flow in the microchannel. The variations of pressure drop and bubble length under different gas and liquid flow rates in microchannel with obstacles are analyzed. The results show that the pressure drop in the obstacle microchannel is higher than that in the barrier free microchannel, and the maximum pressure drop occurs with the obstacle in the center. Through numerical simulation analysis, this is due to the vortex generated after the obstacle, and the pressure drop is positively related to the vortex length. The bubble length of the obstacle microchannel changes within 25% compared to the barrier free channel, and the bubble length becomes shorter as the obstacle approaches the center. Under different flowing conditions, there are three phenomena when bubbles pass through obstacles, including retraction without rupture, retraction with rupture, and direct rupture without retraction. The retraction lengths increase with capillary number increasing in retraction without rupture. The retraction lengths reduce with capillary number increasing in retraction with rupture. When the retraction length decreases to 0, it become a direct fracture without retraction. The variation range of retraction length gradually increases as the obstacle approaches the center. When passing through all obstacles, different breaking and merging laws are displayed under different working conditions. By numerical simulation, different vortex lengths after the obstacle result in different pressure drops, and there exists sever change at the moment of bubble rupture. When passing through the obstacle, the change of bubble shape is affected by the change of liquid phase velocity around it, different velocities in the sub channels on both sides of the obstacle determine the different rules of the two sub bubbles after passing through the obstacle. Related Articles | Metrics

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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 （106）   HTML （2）    PDF （2454KB）（111）       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

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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 （100）   HTML （4）    PDF （36544KB）（111）       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

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Research progress of core monomer separation and purification technology for bio-based materials Kun WANG Xiuling JI Kun LIN Yuhong HUANG The Chinese Journal of Process Engineering    2023, 23 (8): 1137-1149.   DOI: 10.12034/j.issn.1009-606X.222314 Abstract （189）   HTML （8）    PDF （2738KB）（109）       Knowledge map    Save The production of petrochemical-based materials consumes large amounts of non-renewable resources and cause a certain degree of pollution to the environment. The performance of bio-based materials produced by renewable resources can be comparable to that of petrochemical based materials, which is in line with the development concept of green, low-carbon and environmental protection, and provides strong technical support for the realization of the goal of carbon peaking and carbon neutrality. In recent years, with the domestic and international policies tilted to the bio-based materials industry, bio-based materials have become a new material for domestic and international development, providing a good opportunity for the development of bio-based materials industry. The core monomer of bio-based materials produced by biological method has the advantages of mild production conditions, low price, and green environmental protection. But the complex composition within the fermentation broth as well as the low concentration of monomers and the difficulty of separation have seriously restricted the development of the whole industry of bio-based materials. The production of bio-based materials requires high-purity monomers, and a small amount of impurities affect the appearance and performance of bio-based materials. The existing research and application of separation of core monomers of bio-based materials has developed the process of obtaining high purity separation and purification of core monomers of bio-based materials by taking full advantage of chemical separation technology. This review briefly introduces the current status of the production of bio-based materials, reviews the research progress of several widely used separation and purification technologies for core monomers of bio-based materials in recent years, analyzes the advantages and disadvantages of current separation technologies. Finally providing an outlook on the development trend of separation and purification technologies for core monomers of bio-based materials. Related Articles | Metrics

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Study on purification of human serum albumin by novel electrostatic coupled affinity chromatography Sidong WANG Liuyang WANG Xue FENG Songping ZHANG Wanzhong ZHANG Jian LUO The Chinese Journal of Process Engineering    2023, 23 (11): 1599-1607.   DOI: 10.12034/j.issn.1009-606X.223062 Abstract （86）   HTML （1）    PDF （15419KB）（105）       Knowledge map    Save Human serum albumin (HSA), the most abundant protein in human serum, accounting for about 40%~60% of the total serum protein content. When purified by commercialized albumin affinity medium (Cibacron Blue F3GA), the yield of albumin is low, meanwhile, the ligand of Cibacron Blue F3GA had disadvantages of high toxicity and easily to fall off. In this study, a novel electrostatic coupling affinity medium was prepared and used to purify albumin from human serum by one-step chromatography. New electrostatic coupling affinity medium DASA-Sepharose (3,5-diaminobenzoic acid n-octyl succinic anhydride-Sepharose) was prepared with n-octyl succinic anhydride as affinity ligand coupled to agarose microsphere with 3,5-diaminobenzoic acid as spacer arm. The carboxyl functional group on the DASA-Sepharose spacer arm adsorbed albumin through electrostatic interaction, and then cooperated with the n-octyl succinic anhydride affinity ligand to achieve electrostatic coupling affinity adsorption, which greatly improved the adsorption capacity and maintained the high specificity of affinity adsorption. The effects of different NaCl concentrations and pH values on adsorption equilibrium were investigated with BSA as model protein. When NaCl concentration was 0.025~0.06 mol/L, the saturated adsorption capacity (Qm) was almost unaffected. When NaCl concentration was 0.1 mol/L or above, Qm decreased significantly. The Qm for BSA reached 75.43 mg/mL medium in 20 mmol/L PBS at pH=5.00. Compared with the Qm (20 mg/mL medium) of the commercialized albumin affinity medium Cibacron Blue F3GA, the Qm of DASA-Sepharose increased by about 2.7 times. The HSA could be directly extracted from human serum using the novel electrostatically coupled affinity chromatography medium with high purity (98.20%) and high yield (94.34%).The secondary structure and small molecule drug binding activity of purified albumin were determined by circular dichroism spectrum and warfarin sodium method, which were basically consistent with the standard human serum albumin. The results demonstrated that the electrostatic coupling affinity chromatography can be efficiently used for HSA purification from human serum, which provided a new approach for the HSA separation from plasma. Related Articles | Metrics

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Research progress of flotation activator for complex copper oxide minerals Haoxiang WANG Peilun SHEN Jinpeng CAI Xiaodong JIA Rong PENG Dianwen LIU The Chinese Journal of Process Engineering    2023, 23 (10): 1381-1389.   DOI: 10.12034/j.issn.1009-606X.222336 Abstract （136）   HTML （10）    PDF （5380KB）（104）       Knowledge map    Save Copper is widely used in industry because of its excellent physical and chemical properties.At present, with the depletion of copper sulfide resources, the development and utilization of copper oxide resources has gradually become the focus of research. As an important source of copper metal extraction, the key to efficient recovery of copper oxide ore is the activation process. However, the existing copper oxide resources have the characteristics of high oxidation rate, complex mineral composition and easy sludge, which makes the beneficiation more difficult. The classical sulfidization-xanthate flotation method can't meet the current requirements of complex copper oxide ore resource separation. In addition, the mechanism of activator acting on mineral surface and the unclear explanation of crystal structure of activated products restrict the development of the theory and method of copper oxide ore separation to some extent. In recent years, a variety of new activators or combination activators have been reported in reference for the complex and difficult-to-beneficiated copper oxide resources. Scholars have made a deeper research and elaboration on the activation mechanism of copper oxide ore based on the existing activation theory, and put forward a variety of effective and practical new theories and methods, which have solved the problem of complex copper oxide ore beneficiation to some extent. In this review, by combing the development of activator for copper oxide ore in recent years, the application and activation mechanism of new activator and new activation method are summarized, aiming at enriching the theoretical system of efficient flotation of copper oxide ore and providing reference for production practice. Related Articles | Metrics

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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 （99）   HTML （1）    PDF （9523KB）（103）       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

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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 （169）   HTML （3）    PDF （9117KB）（101）       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

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Numerical simulation of non-oxidative methane dehydroaromatization reactor based on CPFD method Jinfeng SI Ming GONG Xiaojiao JI Xing LIU Xiaoxun MA The Chinese Journal of Process Engineering    2024, 24 (1): 17-26.   DOI: 10.12034/j.issn.1009-606X.223144 Abstract （103）   HTML （6）    PDF （1924KB）（100）       Knowledge map    Save Non-oxidative methane dehydroaromatization (MDA) is a promising technology for converting methane into high value-added products such as benzene, naphthalene, and hydrogen. The fluidized bed has good mass and heat transfer characteristics and is easy to realize the continuous regeneration of the catalyst, so it is an ideal MDA reactor. The basic research on fluidization in MDA fluidized bed reactors is one of the important links to realize the industrialization of MDA technology. In this work, the coupling model of reactions and hydrodynamics was established, and the fluidized bed reactor of the methane dehydroaromatization catalytic reaction/catalyst regeneration system, which has been constructed by our laboratory, was numerically simulated based on the computational particle fluid dynamics (CPFD) method. Then, the simulated values were compared with the corresponding experimental results, which validated the feasibility of CPFD simulation. Through simulation, the overall gas-solid flow state, the concentration distribution of each component in the gas phase and the catalyst carbon deposition content distribution were predicted. Finally, the effects of different operating conditions such as methane feed flow and catalyst retention in the reactor on the gas-solid two-phase flow and methane dehydroaromatization reaction performance were investigated. The results showed that the increase of methane feed flow rate reduced the methane conversion and improve the selectivity of aromatic products. Increasing the catalyst retention in the reactor can improve the methane conversion, meanwhile, it also made the axial and radial non-uniformity of the gas-solid two-phase distribution in the gas-solid reactor more significant, resulting in increased gas backmixing and lower the aromatic selectivity. This work would deepen the understanding of the gas-solid flow patterns inside the MDA fluidized bed reactor and provide some valuable data support for the industrial reactor scale-up of this technology. Related Articles | Metrics

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Effect of conical distribution plate with slit hole on flow characteristics in fluidized reactor Tiancheng WANG Gong CHEN Dexi WANG Lixin SHAO The Chinese Journal of Process Engineering    2023, 23 (10): 1390-1400.   DOI: 10.12034/j.issn.1009-606X.222472 Abstract （134）   HTML （5）    PDF （1471KB）（100）       Knowledge map    Save Water pollution has gradually become one of the prominent problems restricting the harmonious development of urban ecosystem. At present, the development of efficient wastewater treatment technology has important practical significance to alleviate this problem. Wastewater treatment reactor is the core equipment of wastewater treatment, and the internal flow characteristics affected by its structure have an important impact on water treatment efficiency. Fluidization reactor has become a common sewage treatment equipment because of its high heat and mass transfer rate. In view of the liquid phase back mixing and uneven liquid-solid mixing still exist in fluidized reactor for wastewater treatment. Based on the mobile biofilm wastewater treatment technology and the concept of maximizing the space utilization of integrated wastewater treatment equipment, a rectangular fluidized reactor with slit hole conical distribution plate was designed. The orifice area of the distribution plate gradually increased from the center of the reactor to the outside, and the Euler-Euler multiphase flow model and RNG k-ε turbulence model were used for numerical simulation of the fluidized reactor with a conical distribution plate with slit holes. The effect of the distribution plate structure on the distribution of particles in the reactor was studied by the arrangement of the holes and the cone angle of the slit hole conical distribution plate. The results showed that the conical distribution plate with slit holes can solve the problems of liquid-phase backmixing and uneven liquid-solid mixing, form multiple ring core flows in the reactor, improve the uniformity of particle distribution, and strengthen the liquid-solid mixing. Based on the comprehensive evaluation of particle volume fraction, flow rate, and bed density standard difference, the optimal hole distribution mode of the slit conical distribution plate was determined to be perpendicular to the central axis, and the optimal fluidization effect of the reactor appeared under the cone angle of 120°. Related Articles | Metrics

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Cover and Contents The Chinese Journal of Process Engineering    2023, 23 (8): 0-.   Abstract （88）      PDF （5090KB）（100）       Knowledge map    Save Related Articles | Metrics

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Research progress on multi-objective comprehensive evaluation of urban wastewater treatment processes Han CUI Yuting WANG Huajie LI Di ZHANG Longyi LÜ Zhijun REN Zhi SUN Pengfei WANG Xiaoyang LIU Li SUN Guangming ZHANG Wenfang GAO The Chinese Journal of Process Engineering    2024, 24 (1): 1-16.   DOI: 10.12034/j.issn.1009-606X.223037 Abstract （87）   HTML （6）    PDF （4095KB）（99）       Knowledge map    Save With the rapid development of the wastewater treatment industry, various treatment technologies emerge in endlessly, which have largely solved the pollution problem and caused environmental impacts. In order to select more efficient wastewater treatment technologies, various evaluation methods have been applied in the wastewater treatment industry under the background of carbon peaking and carbon neutralization. This review summarizes the current research situation of environmental and economic impact evaluation which are widely used in urban wastewater treatment plant (WWTP) and proposes the "5E" assessment system based on the existing research. At present, the assessment system mainly focuses on the environmental impact assessment based on life cycle assessment, focusing on the impact of eutrophication potential, global warming potential, and energy consumption on traditional and unconventional wastewater treatment technologies in WWTP. Economic evaluation is mainly divided into cost and benefit evaluation. Through the analysis of cost and profit in economic evaluation, the energy cost is very important in each treatment process, where the recovery and utilization of biogas can effectively improve the profit. In addition, carbon footprint assessment and organic contaminants toxicity evaluation have gradually become the research hotspot. In each part of this article, the evaluation of technology in wastewater treatment process is mentioned. At last, the "5E" assessment system (i. e., comprehensive environmental impact assessment, economic evaluation, carbon footprint evaluation, organic contaminants toxicity evaluation, and technology evaluation) is proposed to effectively solve the multi-objective comprehensive assessment problem of the urban WWTP. This research can support the sustainable development of the wastewater treatment industry and the realization of carbon peaking and carbon neutralization targets. Related Articles | Metrics

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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 （160）   HTML （14）    PDF （1013KB）（99）       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