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Thermal Decomposition of Glucose and Sucrose by Kinetics Analysis CHEN Ying-qin HE Han-bing LIU Chang LU Xiao-hua;    2010, 10 (4): 720-725.   Abstract （2274）      PDF （238KB）（4674）       Knowledge map    Save Thermal decomposition process of glucose and sucrose was studied by TG-DTA. The Kissinger, Friedman and non-linear regression methods were used to obtain the reaction decomposition mechanism and kinetic parameters. The results showed that the decomposition of glucose was much easier than that of sucrose. The orders of decomposition reaction for glucose in two stages were 2 and 1 respectively. However, for sucrose, the order of decomposition reaction in two stages was n and 1 respectively. Non-linear fitting of glucose and sucrose was given a complete thermal decomposition reaction pathways and kinetic parameters. The activation energy of glucose in three stages was respectively 132, 150 and 253 kJ/mol, and pre-exponential factor 11.6, 11.1 and 19.6 s-1, and activation energy of sucrose in two stages was 105 and 229 kJ/mol, and pre-exponential factor 8.2 and 18.6 s-1. Related Articles | Metrics

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Research review in regulating interfacial interaction on MOF-based mixed matrix membranes for gas separation Lili GONG Ju BAI Can WANG Wei LAI Linglong SHAN Shuangjiang LUO Zhichang LIU The Chinese Journal of Process Engineering    2023, 23 (4): 489-500.   DOI: 10.12034/j.issn.1009-606X.223054 Abstract （1129）   HTML （38）    PDF （7406KB）（4025）       Knowledge map    Save Mixed matrix membranes (MMMs) have attracted substantial attention for gas separation, combining the advantages of organic polymers and inorganic fillers, which are expected to solve the Trade-off effect. Metal organic frameworks (MOF), as a kind of innovative filler, provided promising development opportunities for MMMs, thanks to high surface area and porosity, adjustable pores, and low density, etc. These unique physical and chemical properties promoted the application in gas adsorption, separation, and storage. MOF is regarded as good compatibility with the polymer matrix because the organic linkers in MOF are more similar to the organic chain of the polymer compared with traditional inorganic materials (molecular sieve or metal oxide, etc.). Gas separation performance is improved by incorporating MOF into the polymer matrix, which is expected to balance the Trade-off effect. However, the separation performance of MMMs is not simply the sum of the two phases and is far below the predicted theoretical value by the material simulation in most cases. One of the key reasons for these non-ideal morphologies resulting from poor interfacial compatibility, including the non-selective interfacial voids, polymer rigidified, and pore blockage, which reduce the separation performance of MMMs. Therefore, good interfacial compatibility plays a key role in MMMs. Constructing effective interface interactions is a feasible strategy to improve interface compatibility. Thus, in this review, a comprehensive overview of the main technical challenges in developing MOF-based MMMs and a detailed description of the interface issues are provided. And constructing different interface interactions, including hydrogen bonds, covalent bonds, coordination bonds and others, has been expounded through various methods and strategies in the last five years. Finally, it aims to summarize the positive effects on the properties of MMMs through effective and strong interface interactions, guiding the future development of MOF-based MMMs. Related Articles | Metrics

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Kinetics on Chlorination Process of La2O3 and CeO2 by Ammonium Chloride SHI Wen-zhong;ZHANG Xin;ZHAO Yong-he;WANG Jing-yan;ZHU Guo-cai    2005, 5 (1): 23-28.   Abstract （3072）      PDF （101KB）（3264）       Knowledge map    Save Using ammonium chloride (NH4Cl) as a chlorinating agent, the effects of chlorinating temperature, time and NH4Cl dosage on chlorination of La2O3 and CeO2, and the thermal decomposition of LaCl3 7H2O and CeCl3 7H2O were examined. The results show that NH4Cl directly participates the chlorination reaction, and HCl from pyrolysis of NH4Cl also contributes to the chlorination reaction. CeCl3 and LaCl3 can cause gas phase hydrosols formation or oxidation reaction which generates LaOCl, CeOCl and CeO2. The apparent activation energies of La2O3 and CeO2 chlorination reactions, Ea, are 43.73 and 140.67 kJ/mol respectively. The process is mainly controlled by the interfacial chemical reaction. Related Articles | Metrics

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Synthesis of Y2O3:Eu3+ Microrods by Hydrothermal Method and Their Fluorescent Properties SONG Jin-ling SUN Qian LIANG Jia-bao LI Xia CAI Ying ZHANG Yin    2010, 10 (5): 950-955.   Abstract （2116）      PDF （669KB）（2938）       Knowledge map    Save Y2O3 and Y2O3:Eu3+ were synthesized by hydrothermal method, and the factors affecting product crystalline structure examined, such as reaction temperature, reaction time and NaOH solution concentration. The results showed that the reaction conditions for better crystal formation were with the temperature of 180℃, reaction time of 24 h and NaOH concentration of 2 mol/L. Additionally, the influence of the molar ratio of Y3+ to Eu3+ on their fluorescence properties was studied. When the ratio of n(Y3+) to n(Eu3+) was 100 to 5, the fluorescence intensity of Y2O3:Eu3+ exhibited best. TEM analysis showed that the morphology of Y2O3:Eu3+ particles demonstrated mainly microrods with the diameters of 0.2~0.6 μm and lengths of several micrometers. Related Articles | Metrics

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Process Simulation and Techno-economic Analysis on Hydration and Hydrogenation Technology of Acrolein for 1,3-Propanediol Production ZENG Hong FANG Bai-shan QU Yin-di    2013, 13 (4): 626-632.   Abstract （1493）      PDF （274KB）（2841）       Knowledge map    Save Based on laboratory and pilot experiments of hydration and hydrogenation of acrolein for production of 1,3-propanediol (PDO), the Superpro Designer? emluator was applied to simulate the scale-up process for 10000 t/a PDO production, coupling with costing and economic evaluation on the flowsheet. Simulation results show that the process design is reasonable with main process data complying with experimental results. The economic analysis indicates that raw material cost shares 49% of operating cost, equipment purchase cost is about 22.42 million yuan and the total investment is of approximately 150.88 million yuan. The expected returns on investment reach 28.21% as the after-tax profit is about 42.56 million yuan annually. Related Articles | Metrics

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Leaching Kinetics of Silver from Sintering Dust with Thiourea CHANG Jun ZHANG Er-dong ZHOU Jun-wen ZHANG Li-bo PENG Jin-hui REN Xiao-peng Chin. J. Process Eng.    2015, 15 (4): 567-573.   DOI: 10.12034/j.issn.1009-606X.215177 Abstract （1177）      PDF （290KB）（2715）       Knowledge map    Save Using the sintering dust containing Ag from iron and steel metallurgical process as raw material, on the basis of phase analysis, an efficient leaching process of silver with thiourea from the dust was proposed. The effects of particle size, temperature, concentration of thiourea, leaching time and stirring speed on leaching rate of silver were examined. The results showed that silver leaching rate from water washed sintering dust could reach 90% under the conditions of ratio of liquid volume to solid mass 8 mL/g, 22 g/L thiourea and stirring speed at 400 r/min for 120 min. The leaching of silver conformed well to the shrinking core model with internal diffusion control. The apparent activation energy of silver reaction was calculated as 29.7 kJ/mol and the reaction order in acidic thiourea solution was approximately 1. Related Articles | Metrics

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Progress of the Study on Bacillus thuringiensis as Biopesticides ZHU Wei;ZHAO Bing;WANG Xiao-dong;WANG Yu-chun    2004, 4 (3): 282-288.   Abstract （2912）      PDF （93KB）（2666）       Knowledge map    Save Bacillus thuringiensis is one of the most effective and the most widely used microbial insecticides at present. The genetic bacterial strains, the fermentation process and the formulation of Bacillus thuringiensis as biopesticides are reviewed in this paper. The optimization of culture medium, operating conditions and type of fermentors are also addressed. Moreover, the existing problems and suggestions are discussed. Related Articles | Metrics

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Electrochemical Behavior of Mo and W Ions in Acidic Solutions LI Jin-hui XIE Fang-hao QIAO Shan YANG You-ming    2013, 13 (1): 73-77.   Abstract （1150）      PDF （458KB）（2616）       Knowledge map    Save To increase the difference of electrochemical character of tungsten and molybdenum and separate them, molybdophosphate heteropoly acid and tungstophosphoric heteropoly acid solutions were prepared. Electrochemical behaviors of tungsten, molybdenum, molybdophosphate heteropoly acid and tungstophosphoric heteropoly acid in the acidic solution were studied, and some cyclic voltammetry diagrams were obtained. The results showed that the reduction potential of tungsten ion was higher than that of molybdenum ion, and the difference was less than 0.1 V, which means that tungsten could not be separated from molybdenum at this potential difference. Once tungsten and molybdenum reacted with phosphoric acid, the potential values of reduction peaks of molybdophosphate heteropoly acid and tungstophosphoric heteropoly acid were 0.401 and 0.1949 V, respectively, indicating that phosphoric acid increased the potential difference between tungsten and molybdenum. Related Articles | Metrics

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Preparation process of high-quality LiPF6 crystals Yongfeng ZHAO Haitao ZHANG Chin. J. Process Eng.    2018, 18 (6): 1160-1166.   DOI: 10.12034/j.issn.1009-606X.217428 Abstract （2013）      PDF （815KB）（2450）       Knowledge map    Save Much more attentions are being devoted to high performance energy storage and conversion devices to conquer global warming issue and energy crisis. Lithium-ion battery, the most promsing device, is composed of anode, cathode, separator and electrolyte. Note should be highlighted that the performance of battery is determinded by electrolyte, espcially the safety issue. The demand of lithium-ion batteries and their electrolytes is growing rapidly with the rapid development of new energy vehicles recently. Lithium hexafluorophosphate (LiPF6) crystal is a white crystal with trigonal crystallographic structure. It is the key electrolyte material for Li-ion batteries. LiPF6 is combustible, corrosive and of poor thermal stability. Therefore, some toxic and corrosive precursors are employed, and their synthesis is required to be conducted within an anhydrous and anaerobic environment. Furthermore, many high temperature and low temperature treatments are involved in the synthetic procedure. Therefore, it is a huge challenge to produce high-purity LiPF6 crystals with an electronic grade in an industrial-scale. Fortunately, some industrial processes have been developed successfully by domestic enterprises even there is still some room for improving them. Here, the synthetic methods of LiPF6 and the domestic large-scale production processes are reviewed with the hope of providing some knowledge for future upgrade of the industrialized LiPF6 processes and a guideline for developing new synthetic routes. This review will concentrate on the development and intrinsic correlation among market demand of lithium-ion battery, role of electrolyte in lithium-ion battery, LiPF6 industrialized production procedures, and planned incremental capacity. In addition, the perspectives of potential electrolyte are summarized on basis of the progress of high-capacity and high-voltage electrode materials. There is no doubt that the future emphasis should be paid to the optimization of process, true demand of market, novel lithium salt, fluoridized solvents, and green techniques. Reference | Related Articles | Metrics

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Knowledge on Particle Swarm: The Important Basis for Multi-scale Numerical Simulation of Multiphase Flows MAO Zai-sha    2008, 8 (4): 645-659.   Abstract （1893）      PDF （563KB）（2284）       Knowledge map    Save Numerical simulation of multiphase flows in processing equipment in process industry with two-fluid model and Eulerian-Lagrangian approach requires the constitutive equations describing the interactions between the dispersed phase of high concentration and the continuous phase. The status of research on the forces on solid and fluid particles and the topics remaining to be tackled are reviewed. As compared with the knowledge on drag of single solid particles, study on particle swarms and on other forces is not sufficient to meet the needs of numerical simulation of multiphase flows. Thus, thorough study on the particle swarms and clusters becomes the key to accurate multi-scale simulation of multiphase flows. Besides, the development of efficient algorithm dealing with the simultaneous non-uniformity on equipment and mesoscopic scales is recognized as an important issue to be resolved. Related Articles | Metrics

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Biosynthesis of Polyhydroxyalkanoates by Ralstonia eutropha with Short-chain-length Organic Acids YAN Qun; DU Guo-cheng; CHEN Jian    2003, 3 (5): 0-0.   Abstract （4093）      PDF （257KB）（2255）       Knowledge map    Save Separation of dimethyl carbonate (DMC) and methanol (MeOH) is very difficult due to the azeotrope of DMC and MeOH, the pressure swing method is an effective method for separation of DMC and MeOH azeotrope. In this paper, a joint process of high-pressure distillation and atmospheric distillation was investigated. Binary interaction parameters of the UNQUAC model between MeOH and DMC were regressed against experimental data of vapor liquid equilibria of MeOH and DMC, the applicable range of the model is: pressure 0.1~1.5 MPa, temperature 337~440 K. Based on the thermodynamic model, the separation flowsheet, inclnding a high-pressure distillation column and an atmospheric distillation column in series, was simulated and analyzed. Sensitivity of operation factors was discussed and the optimum operation parameters were proposed. The optimal parameters of the high-pressure distillation column were as follows: stage number 40, feed stage 29, reflux ratio 7~10, operation pressure 1.0~1.5 MPa. Related Articles | Metrics

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Research Progress on Extracting Potassium and Preparing Compound Fertilizer from Potassium Feldspar Yihan SONG Hongmei LI Shuhua MA Xiaohui WANG Xiaozhan MU Shili ZHENG Chin. J. Process Eng.    2018, 18 (2): 241-257.   DOI: 10.12034/j.issn.1009-606X.217285 Abstract （1393）      PDF （779KB）（2098）       Knowledge map    Save A variety of potassium extracting technologies from potassium feldspar have been developed at home and abroad. According to the reaction principle and technological process, these technologies are classified and introduced. The characteristics of various technologies are analyzed, and suggestions for improvement are given. In view of the problems of long process, high cost, poor economic benefits of these potassium extracting technologies from potassium feldspar, it is pointed out that the preparation of potassium feldspar as a multi-element compound fertilizer or soil conditioner should be carried out in the future. The research progress in this direction is introduced. By analyzing the fine characteristics of multi-element fertilizer prepared by hydrothermal method, it is indicated that hydrothermal method has extensive application prospect. Reference | Related Articles | Metrics

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Microrganism Metabolic Engineering in Lactic Acid Production WANG Hai-yan;LIU Ming;WANG Hua-jun;CAO Zhu-an    2006, 6 (3): 512-516.   Abstract （2588）      PDF （209KB）（2085）       Knowledge map    Save Metabolic engineering can regulate the metabolic networks of the microbial cells. It plays an important role in selecting microorganisms and optimizing the process to enhance metabolites production. The progress of the metabolic engineering research in lactic acid production was reviewed. Metabolic pathways in homo-fermentation and hetero-fermentation for lactic acid production were compared. The metabolic model of lactic acid bacteria, the application of lactate dehydrogenase and the production of lactic acid with Rhizopus oryzae fermentation were summarized. The gene regulatory knockout of ethanol metabolic pathway for improving the lactic acid production was introduced. The influences of bioinformatics and stress response on the metabolism of lactic acid were discussed. And the trends in microbial production of lactic acid were also predicted. Related Articles | Metrics

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Research progress of ammonia adsorption materials Junli WANG Shaojuan ZENG Neng CHEN Dawei SHANG Xiangping ZHANG Jianwei LI Chin. J. Process Eng.    2019, 19 (1): 14-24.   DOI: 10.12034/j.issn.1009-606X.218171 Abstract （3247）      PDF （1034KB）（2083）       Knowledge map    Save Ammonia is a typical toxic pollutant and also one of the main causes of the formation of PM2.5. The emission of industrial tail gases containing a large amount of ammonia not only seriously affects the environment and health of human beings, but also results in serious waste of ammonia sources if directly discharged into the atmosphere. Because of their abundant pore structures and large specific surface areas, good adsorption characteristics and mechanical stability, porous materials have attracted a lot of attention in gas adsorption, especially in ammonia removal. Different porous materials can effectively absorb ammonia through the physical or chemical interaction between ammonia and their special pore structures or action sites. The adsorption method for ammonia removal has the several advantages, such as high selectivity, easy recovery and low energy consumption, so it is widely used in many industrial processes. In this review, the recent research status and progress of ammonia removal using different porous materials were reviewed, mainly focused on the research around the ammonia adsorption performances of zeolite, silica gel, activated carbon, graphene oxide, porous organic polymer, covalent organic frameworks (COFs), metal?organic frameworks (MOFs) materials before and after modification, and the research progress of supported ionic liquids materials for ammonia separation in recent years was also introduced. Ionic liquids, as a class of green medium, have several unique advantages for ammonia removal, such as low vapor pressure, high gas selectivity, high thermal stability, tunable structures and properties. Supported ionic liquids materials can combine the characteristics of both ionic liquids and porous materials, which can break the traditional restriction of ionic liquids in industrial applications and providing a novel pathway for ammonia removal applications. Finally, given the main problems of the current development on ammonia removal and recovery using porous materials, the future research directions and solutions had been put forward. Reference | Related Articles | Metrics

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Phase Transition and Transition Temperature Hysteresis of VO2 Thin Film HU Zai-yong; XU Chu-shao; YANG Shao-li; CHEN Guang-bi    2003, 3 (5): 0-0.   Abstract （4266）      PDF （49KB）（2077）       Knowledge map    Save The VO2 thin film was prepared by the colloid method with industrial V2O5 as raw material. The properties of the VO2 film such as resistance abrupt drop temperature, phase transotion temperature hysteresis are examined. The results show that the VO2 thin film phase transition temperature is 35oC. Preparation method and substrate show greater effect on resistance abrupt change order, which can reach 2~3 order if common glass or quartz glass were employed in underlay by H2 reduction process, while it can reach 1.5~2 order of magnitude by N2 thermal decomposition. The resistance abrupt change order of magnitude is larger for VO2 film with quartz glass as substrate, the transition temperature hysteresis is 1~6oC, and closely related with the resistance abrupt change order, underlay, substrate and preparation method. Related Articles | Metrics

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Progress in Preparation of High-purity Anhydrous Magnesium Chloride ZHOU Huan;YUAN Jian-jun    2004, 4 (3): 276-281.   Abstract （2905）      PDF （57KB）（2018）       Knowledge map    Save Anhydrous magnesium chloride is the raw material of electrolyzed metal magnesium and an important intermediate of some catalyzers or medicines. Anhydrous magnesium chloride may be prepared from materials containing magnesium chloride such as magnesium chloride hydrate, carnallite or bittern by different dehydrating methods of organic solvent distillation or molecular sieve absorption, gas protective heating, discomposing the MgCl2-NH3 complex that can be composed from high boiling-point polar-solvent system, water-ammonia system, low boiling-point mixed-solvent system. On the other hand, anhydrous magnesium chloride may also be prepared by chloridizing magnesium oxide, which converted from magnesite, brucite, or Mg(OH)2, in gaseous medium, or molten salt medium. For several decade innovation, some progress has been made for the anhydrous magnesium chloride preparation. However it still needs more deep study to change the traditional technology from complex process, high cost, serious pollution and grievous eroding, into the green technology with simple process, low cost, non-pollution and non-eroding. Related Articles | Metrics

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Formate Dehydrogenase and Its Application in Cofactor NADH Regeneration HUANG Zhi-hua;LIU Ming;WANG Bao-guang;ZHANG Yan-ping;CAO Zhu-an    2006, 6 (6): 1011-1016.   Abstract （2154）      PDF （204KB）（1979）       Knowledge map    Save NADH-dependent oxidoreductases are valuable tools for the biological synthesis of fine chemicals and chiral compounds. As the reducing equivalent, cofactor NADH plays a critical role in those reactions. Due to the high cost of the NADH cofactors, in situ NADH regeneration is required for preparative applications. NAD+-dependent formate dehydrogenase (FDH) is an abundant enzyme that plays an important role in energy supply of methylotrophic microorganisms. FDH captures increasing attention in recent years, and is widely used in enzymatic syntheses of chemical compounds as a versatile biocatalyst for NADH regeneration consumed in the main reactions. This review covers the latest developments in cloning genes of FDH from various sources, studies of its catalytic mechanism and physiological role, and its application for NADH regeneration from the following aspects: chemical stability, thermal stability and cost. Future development of FDH used as NADH regeneration platform is also illustrated. Related Articles | Metrics

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Research Advances in Acidity Characterization of Acid Catalysts Liuyang WANG Guoying ZHAO Baozeng REN Suojiang ZHANG Chin. J. Process Eng.    2017, 17 (6): 1119-1126.   DOI: 10.12034/j.issn.1009-606X.217148 Abstract （1501）      PDF （446KB）（1959）       Knowledge map    Save Acid catalyst has been widely used and well-studied in chemical process and their catalytic activities are normally dictated by their acidities. Determination of acidity of acid catalyst, such as type, amount (concentration), and strength, are the great significance for achieving desired results of catalytic reactions. In this mini review, the characterization methods for acid type, acid amount, acid strength and their recent progresses were summarized, and the merits and disadvantages of each method were also reviewed with specific focus on the progress of the three characterization methods in acid type, structure and application of the catalysts. It is of great significance to help readers fully understand the mechanism of acid catalysis and select suitable catalysts. Reference | Related Articles | Metrics

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Pyrolysis of Straw Obtained from Stagewise Treatment YANG Chang-yan;YANG Xue-min;LV Xue-song;YAO Jian-zhong;LIN Wei-gang    2005, 5 (4): 379-383.   Abstract （2821）      PDF （236KB）（1955）       Knowledge map    Save The pyrolysis characteristics of wheat straw with steam-explosion and solid fermentation treatment were investigated by the thermogravimetry coupled with the Fourier infrared spectroscopy to analyze the evolved gasses. The pyrolysis process with the increase of temperature from TG can be divided into four stages, including drying stage (30~150℃), transitional stage (150~200℃), pyrolysis stage (200~600℃), and carbonization stage (600~900℃). The results of pyrolysis from TG-FTIR show that the process can be divided into two steps: (1) splitting of hydroxide radicals, chain scissions and depolymerization, accompanied by evolution of water, acids, aldehydes, compounds containing C?O?C groups and CO, CO2, CH4, etc.; (2) aromatization and formation of graphite layers, accompanied in turn by evolution of CH4, CO2 and CO. The yields of uncondensable gases and carboxyl compounds decrease after steam explosion/solid fermentation treatment, but the yield of pyrolysis liquid increases by the stagewise treatment. Related Articles | Metrics

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Characteristics of Water Quenched Copper-containing Slag and Separation of Iron and Silicon from It ZHAO Kai CHENG Xiang-li QI Yuan-hong ZHEN Chang-liang SHI Xue-feng    2012, 12 (1): 38-43.   Abstract （1190）      PDF （492KB）（1900）       Knowledge map    Save A mineralogical study of water quenched copper-containing slag was carried out with XRD, SEM, chemical analysis, etc. Fayalite is the major phase and copper exists in matte in the slag. The slag is amorphous, and its structure compact. The matte phase is not fully crystallized, its particle size is below 5 mm, iron and silicon exist mainly in fayalite, beneficiating method can not separate Fe and Si effectively. A new technology of rapid solid-phase reduction and high temperature smelting was proposed, and experiments were carried out. The experimental results show that the high copper and iron recovery rates can be achieved under the conditions of basity at 0.5, final smelting temperature of slag above 1300℃, smelting and separation temperature above 1350℃, and addition of additive, they are 93% and 87%, respectively. The iron and copper left in slag is less than 5% and 0.10% respectively. It means that the slag can be used as construction material, and the process can separate iron and copper, and the comprehensive utilization of copper slag can be achieved. Related Articles | Metrics

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Leaching of a Low-grade Refractory Tantalum–Niobium Ore by KOH Sub-molten Salt ZHOU Hong-ming; ZHENG Shi-li; ZHANG Yi    2003, 3 (5): 0-0.   Abstract （3503）      PDF （197KB）（1871）       Knowledge map    Save Production of lignin peroxidase (LiP) and manganese peroxidase (MnP) in three kinds of reactors (stirred tank reactor, bubble column reactor and aeration reactor) by Phanerochaete chrysosporium was studied. High activity of enzymes, especially for LiP, was obtained in the aeration reactor. The production of enzymes and decoloration of orange I were investigated in semi-continuous culture and continuous culture respectively. High activity of enzymes for a long period of time was detected in the semi-continuous culture, in which five batches of dye wastewater could be decolored to more than 90% and the specific decloration rate of orange I was above 46.7 g/(g×d) when the proportion of replacement was 1/2, while enzymes decayed rapidly and poor decoloration was gained in the continuous culture. The application of semi-continuous culture in the aeration reactor was tried for the decoloration of four batches of printing-wastewater, and the decelerations rate of the first three was all above 90%. Related Articles | Metrics

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Synthesis of 13X Zeolite and MCM-41 Mesoporous Materials and Treatment of Cd2+-containing Wastewater YANG Jing;MA Xiao-guang;MA Hong-wen;Ray L. Frost    2007, 7 (2): 399-403.   Abstract （1659）      PDF （447KB）（1870）       Knowledge map    Save The 13X zeolite was synthesized hydrothermally by the calcined natural rocks, K-feldspar, from Jixian county, Tianjin, China. The ordered mesoporous molecular sieve material MCM-41 was synthesized by hydrothermal method using fumed silica, NaOH and CTAB. The synthesized 13X zeolite and MCM-41 samples were characterized by XRD, N2 adsorption, SEM and TEM methods. The results show that the MCM-41 has larger pore size (2~4 nm) and higher specific surface area than the microporous 13X zeolite. Moreover, the 13X zeolite and MCM-41 were used to treat Cd2+-containing wastewater. The amounts of Cd2+ adsorbed onto the 13X zeolite and MCM-41 were studied in different adsorbent amounts, pH values and mixing times. Theoretically, the adsorbed amount of Cd2+ onto MCM-41 should be much more than that of 13X-zeolite because of its higher specific surface area and larger pore size. However, it is shown that the 13X zeolite (with the pore size of about 0.7 nm) adsorbs much more Cd2+ than the MCM-41 sample in Cd2+ aqueous solution. The adsorption rate of the 13X zeolite is over 99%, and the adsorption rate is below 80% for the MCM-41. The 13X zeolite can be used for treating the wastewater containing Cd2+ more effectively than the MCM-41 mainly because of their different chemical compositions, pore structures and surface charges, and the 13X zeolite interaction with Cd2+ by ion exchange and the precipitation as well. Related Articles | Metrics

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Simulation of Current Distribution in Manganese-Silicon Ferroalloy Smelting Arc Furnace with Coke Layer CHU Shao-jun LI Zhong-si HE Ri-fei    2008, 8 (3): 449-452.   Abstract （3127）      PDF （266KB）（1845）       Knowledge map    Save A simulation device for investigating the behavior of current distribution was designed according to the structure characteristic of coke layer molten pool in manganese-silicon ferroalloy smelting arc furnace and similarity theory. NaCl solution with the specific conductance of 10.08~17.97 mS/cm and coke were used as the electric conduction phase to simulate the behavior of electric conduction in manganese-silicon submerged arc furnace. The current distribution relationship of the total current between coke layer and molten slag layer was measured in the molten pool. The results indicated that the relationships among the depth of coke layer, HC, the granularity of coke, DC, the conductivities of electric conduction phases (both in solid and liquid phases, rC and rL), the ratio of current through the bottom of molten pool Ib to total current It followed the following equation, i.e., Ib/It=4.36(rL/rC)1.523(DC/HC)0.186. When operational resistance of melting layer increased, Ib/It would decrease, which was in accordance with the actual process of manganese-silicon ferroalloy production. Related Articles | Metrics

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Plasmid Stability in High Cell Density Cultures of E.coli HB101(pBR322) YU Guo-ce; JIAO Rui-shen; WANG Ji-cheng; WANG Shu-qing    2001, 1 (2): 0-0.   Abstract （3147）      PDF （142KB）（1845）       Knowledge map    Save Plasmid stability and the activity of b-lactamase were examined in the factorial fed-batch cultures of E.coli HB101(pBR322) in a fermentor. No loss of plasmid pBR322 was observed when temperature shifted from 33 oC to 39 oC, pH from 6.4 to 7.2, dissolved oxygen (DO) from 40% to 80%, the feed rate from 5.4 g/h to 10.8 g/h under the condition of density up to 27.3 g/L and the specific growth rate up to 0.73 h-1. The specific activity of b-lactamase, however, decreased in high cell density cultures. Related Articles | Metrics

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Characteristics and Formation Mechanism of Secondary Organic Aerosol BAI Zhi-peng;LI Wei-fang    2008, 8 (1): 202-208.   Abstract （4406）      PDF （237KB）（1812）       Knowledge map    Save The formation of secondary organic aerosol (SOA) is one of the research focuses in atmospheric chemical process. In urban atmosphere, secondary organic carbon constitutes about 17%~65% of the total particulate organic carbon. Monoterpene and aromatics are the most important natural and anthropogenic precursors of SOA, respectively. The volatile precursors react with atmospheric oxidants such as hydroxyl (×OH), nitrate radical (NO3-) and O3 through multiple reaction pathways, producing semi-volatile secondary organics including diacids, multifunctional carbonyls and nitrate organics, etc. Theses compounds can distribute into particulate phase via adsorption and absorption processes, and will alter the property and environmental effects of ambient aerosols. Organic molecular markers are utilized to apportion the sources of atmospheric ambient aerosols, and organic diacids are potential tracers for SOA. In this article, the advances and problems in SOA research are reviewed, and future research recommendations are presented. Related Articles | Metrics

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Adsorption of Methyl Orange on Modified Activated Carbon LIU Jian ZHU Qiu-xiang TAN Xiong-wen YAN Ying ZHANG Hui-ping Chin. J. Process Eng.    2016, 16 (2): 222-227.   DOI: 10.12034/j.issn.1009-606X.215334 Abstract （1756）      PDF （247KB）（1803）       Knowledge map    Save Activated carbon was modified by hydrochloric acid and aqueous ammonia and used as adsorbent to remove methyl orange (MO) from wastewater. The effects of modification condition, shaking speed and temperature on its adsorption performance of MO were examined. The adsorption data were simulated by both adsorption isotherm and kinetic models, and the adsorption thermodynamics was also analyzed. The results showed that the adsorption capacity of hydrochloric acid modified activated carbon for MO was better than that of ammonia modified one. The adsorption equilibrium was achieved with the removal rate of MO 93.7% within 24 h under the conditions of initial MO concentration of 60 mg/L, solution volume of 50 mL, temperature of 20℃ and shaking speed of 100 r/min. The adsorption data of hydrochloric acid modified activated carbon for MO fitted well to Langmuir (RC2>0.95) and Freundlich (RC2>0.97) adsorption isotherm models, and its saturated adsorption capacity reached up to 112.7 mg/g. Thermodynamic parameters, such as DG0<0, and DH0>0, DS0>0, showed that the adsorption of MO on hydrochloric acid modified activated carbon was a spontaneous and endothermal reaction. The adsorption kinetics could be well described by pseudo-second-order kinetic model. The adsorption rate constant increased with the increase of shaking speed. Related Articles | Metrics

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Research progress in preparation and application of high-entropy oxides Houzheng XIANG Feng QUAN Wenchao LI Xiaolei LIU Aiqin MAO Haiyun YU Chin. J. Process Eng.    2020, 20 (3): 245-253.   DOI: 10.12034/j.issn.1009-606X.219228 Abstract （4555）      PDF （834KB）（1779）       Knowledge map    Save As a new type of oxide system, high entropy oxides have broken the traditional design concept of doped oxide and are composed of five or more kinds of oxides in equal or nearly equal mole. Because of its simple structure and excellent performance, it has been widely concerned by researchers at home and abroad in recent years. High-entropy oxides tend to form solid solution structures such as rock-salt type, calcium fluoride type, spinel type or perovskite due to the disordered arrangement of multiple principal elements. Therefore, it shows various excellent performances, especially in energy storage materials and magnetic materials, which has a very broad application prospect. However, there are few research on high-entropy oxides, especially on the application of high-entropy oxides. This work first introduced the preparation methods of high-entropy oxides at home and abroad, mainly including solid state reaction method, pyrolysis method, co-precipitation method, hydro-thermal synthesis method and solution combustion synthesis method. In addition, the advantages and disadvantages of each method were also discussed, and these offered a wide range of flexible approaches for different type of applications of high-entropy oxides. Then the applications of high-entropy oxides as Li-ion electrode materials, giant dielectric materials, magnetic materials and catalytic materials were summarized. At last, the problems of high-entropy oxides in the present research were pointed out, and the future developments were also prospected. This review had certain guiding significance for the expansion of the application of high-entropy oxides subjects in the future direction. Related Articles | Metrics

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Preparation of Microgel by Crosslinking Partially Quaternized Poly(4-Vinyl Pyridine) MA Guang-hui    2003, 3 (4): 0-0.   Abstract （2481）      PDF （170KB）（1773）       Knowledge map    Save For the conversion of hydrogen chloride to chlorine by catalytic oxidation, the suitable catalyst is supported CuO in which there is 12% of copper. It has high activity and its catalytic activity is kept unchanged after running for 200 h. When the process is divided into two stages, oxidative chlorination and chlorination, it is unnecessary to supply heat to the reaction and the conversion of HCl can achieve 100%. The optimal conditions for the stage of oxidative chlorination are: temperature 360~400oC, molar ratio of HCl to O2 2, weight hourly space velocity of the reactants 0.3~0.4 h–1; for the stage of chlorination, the temperature should be about 200oC. Related Articles | Metrics

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Self-assembly Mechanism and Defect Analysis of Colloidal Silica Photonic Crystals ZHAO Xiao-feng;ZHANG Hui;TANG Qing    2003, 3 (5): 0-0.   Abstract （3253）      PDF （167KB）（1767）       Knowledge map    Save Colloidal silica photonic crystals were prepared by using ethanol as medium. Nanospheres with a mean diameter of 238 nm and standard deviation 5.7% were obtained under strictly controlled conditions by using the improved Stober method. In this method, ethanol was proved a better medium than water and the prepared photonic crystals had fewer defects. The diffraction to incident infrared light obeyed the Bragg equation. The formation mechanism and defect formation of colloidal photonic crystals were also discussed. Related Articles | Metrics

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Review of additives for electrolyte of sodium-ion battery Yuyue GUO Xiaoying ZHAI Ningbo ZHANG The Chinese Journal of Process Engineering    2023, 23 (8): 1089-1101.   DOI: 10.12034/j.issn.1009-606X.223104 Abstract （1762）   HTML （84）    PDF （3494KB）（1764）       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