Volumn Content

The Chinese Journal of Process Engineering 2018 Vol.18 Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Recent Advances on Recovery and Separation of Biomass-based Organic Acids Ling YAN Hongxin FU Xudong WANG Yaqin SUN Jianying DAI Zhilong XIU Chin. J. Process Eng.    2018, 18 (1): 1-10.   DOI: 10.12034/j.issn.1009-606X.217166 Abstract （1194）      PDF （510KB）（737）       Knowledge map    Save Organic acids such as lactic acid, succinic acid, citric acid, itaconic acid, and malic acid have important application in industry. The demand for organic acids increased dramatically with the development of food, medicine and chemical synthesis. The fermentative production of organic acids has developed into an important and mature branch in the field of biological engineering. The fermentation-based routes for the industrial production of organic acids have some problems such as low product concentration, complex composition of fermentation broth and downstream processing. Because of its good hydrophilicity, similar physical and chemical properties, separating and purifying organic acids from fermentation broths is difficult. The separation of organic acids becomes the main bottleneck for organic acid production by biological processes. A number of processes for organic acids recovery from fermentation broths have been studied in the literatures, including precipitation, extraction, adsorption, ion exchange, membrane separation, electrodialysis and esterification. Through the comparison of various separation methods, it is found that a single separation method is difficult to separate organic acids effectively. The integration of different separation methods can simplify the separation process and obtain excellent separation effect. In addition, continuous or semi-continuous production of organic acid is an important direction of future fermentation industry by the novel methods of separation coupling fermentation. Reference | Related Articles | Metrics Select Research Progress on Activation and Deactivation of Sphalerite Flotation Jialei LI Kaiwei SONG Dianwen LIU Xiaolin ZHANG Jianmin LI Shunfu AO Chin. J. Process Eng.    2018, 18 (1): 11-19.   DOI: 10.12034/j.issn.1009-606X.217183 Abstract （1153）      PDF （543KB）（309）       Knowledge map    Save The activation and deactivation of sphalerite flotation were reviewed. The sources of ions which could activate sphalerite flotation were discussed. The mechanism of activation is affected by pH value, the potential of slurry, concentration of the activator and lattice imperfection. Sphalerite and marmatite are effectively activated by ammoniacal copper complex ion, which can lower the cost and improve the quality of zinc concentrate. The deactivation will be generated by removing the activate ions or hydrophilic film coating on sphalerite surface. And the research directions of theory and technologies of flotation for polymetallic sulphide ores based on the use of recycled water, inside and outside environmental of minerals and new flotation agents were also predicted.Key words: sphalerite; flotation; activation; deactivation; unavoidable ions Reference | Related Articles | Metrics Select Research Progress of Lithium Carbonate Preparation and Purification Process Chunlong ZHAO Zhi SUN Xiaohong ZHENG Wenfang GAO Yanling ZHANG Xiao LIN Chin. J. Process Eng.    2018, 18 (1): 20-28.   DOI: 10.12034/j.issn.1009-606X.217234 Abstract （1782）      PDF （1258KB）（729）       Knowledge map    Save With the extensive application of lithium-ion batteries and the rise of electric vehicle industrial in recent years, the demand of lithium is increase year by year. Lithium carbonate as one of the most important basic lithium salt, widely used in lithium-ion batteries, mainly used to synthesize lithium-ion battery cathode material. Currently, the preparation of high purity lithium carbonate is mainly through extracting lithium from lithium ore and salt lake brine, and then through purification process. The purification methods mainly including carbonization, custicization, electrolysis, lithium carbonate recrystallization and ion exchange, etc. However, there are many problems in the preparation and purification of lithium carbonate, such as deep separate lithium and sodium, preparation of high purity lithium carbonate etc. This paper reviews the preparation and purification ways of lithium carbonate, the exisiting problems and prospects for preparation and purification lithium carbonate are proposed. Reference | Related Articles | Metrics Select Trajectory Characteristics of Spherical Particle Sedimentation under Isothermal Conditions Jianzhong CHANG Ying ZHANG Hantao LIU Chin. J. Process Eng.    2018, 18 (1): 29-34.   DOI: 10.12034/j.issn.1009-606X.217167 Abstract （823）      PDF （495KB）（317）       Knowledge map    Save Trajectory characteristics of spherical particle sedimentation under the effect of gravity were studied using particle image velocimetry，PIV. The law of particle sedimentation, the experiment of different releasing locations under same Reynolds numbers and the same releasing location under different Reynolds numbers were examined. The results show that when Re≤100, despite different globule releasing locations, final stable settlement position of the particles was at the center under the same Re. When the particle's releasing position was symmetrical along the centerline, the trajectory of the particle sedimentation was also symmetrical along the center. With the increase of Re, the final sedimentation trajectory of the particle changed from a stable straight line to a stable periodic swing curve. In conclusion, the equilibrium position of the particles was independent of the initial release position of the particles and the value of Re, but the trajectory of the particles was related to the position and Re. The simulated and experimental results were almost the same. Reference | Related Articles | Metrics Select Comparison of LBM and CFD for Hydrodynamic Simulation of Cross-flow Tube Bundle Mengxia YUAN Xiuchen QIAO Chin. J. Process Eng.    2018, 18 (1): 35-40.   DOI: 10.12034/j.issn.1009-606X.217169 Abstract （1104）      PDF （1319KB）（249）       Knowledge map    Save A meshless approach based on the LBM (Lattice?Boltzmann Method) was employed for simulating a cross-flow heat exchanger. The calculated hydrodynamics was compared with the CFD for discussion. The results showed that the LBM combined with LES predicted the turbulent hydrodynamics of the heat exchanger reasonably. The simulated fluid velocity distributions agreed with the referenced experimental data. The calculation deviations on key physical quantities were also acceptable for engineering purpose. The subsequent comparison indicated that the LBM and CFD had almost the same calculation results and cost. There was no apparent difference in the computational efficiency between the two models. Nevertheless, the CFD simulation required more effort in the pre-process for mesh generation. This problem was especially serious for simulating the heat exchangers with complex internals. In contrast, the LBM was a particle based method. It predicted the hydrodynamics by tracking the probability distribution function to an equilibrium state. The concept of discrete grids was replaced by the lattice. It only needed to specify the lattice size regardless of the geometrical adaption. Hence, the LBM modeling was considered to be more efficient and it was suggested highly for the simulation design of complex geometrical structures. Reference | Related Articles | Metrics Select Experimental and Numerical Research on Heat Transfer Characteristics of Three-dimensional Flue Gas Heat Exchanger Xun MO Dongsheng ZHU Chengdi LIN Chin. J. Process Eng.    2018, 18 (1): 41-48.   DOI: 10.12034/j.issn.1009-606X.217198 Abstract （656）      PDF （3285KB）（420）       Knowledge map    Save A comprehensive and detailed test had been performed for three-dimensional tube exchange components and traditional H-type fin tube through a prototype to investigated their heat transfer characterization. The results showed that the total heat transfer coefficient of the three-dimensional tube heat exchanger is 2 to 3 times that of the H-type fin tube heat exchanger, and the resistance of the heat exchanger in staggered arrangement was bigger than that of in-line arrangement. Besides, the modified correlation of gas side convective heat transfer was more realistic, and the calculated result is about 26% higher than that of the original correlation. FLUENT software can simulate the actual situation of three-dimensional tube heat exchanger, and the simulation results error is relatively small. Related Articles | Metrics Select Experimental Study on the Wetting Ability of Falling Film Shi LIN Zheng ZHANG Kunyu ZHUANG Xi LIU Zhoutian GE Junhan CHEN Xuelai LI Chin. J. Process Eng.    2018, 18 (1): 49-56.   DOI: 10.12034/j.issn.1009-606X.217203 Abstract （832）      PDF （1586KB）（211）       Knowledge map    Save Influences of various parameters such as liquid inlet flow, feeding height, inlet aperture, diameter of tube and inclined angle on the wetting ability of liquid film were studied. Image processing method was adopted to measure wetting length of liquid film on the plain tube with different parameters. The experimental results showed that with the increase of the flow rate, the wetting ability of the liquid film stays the same after reaching the peak. When the feeding height is investigated, the flow pattern needs to be considered. The effect of feeding height on wetting ability is negligible with the flow pattern of columnar flow. Wetting ability decreases firstly then remains unchanged with increasing feeding height under columnar-sheet flow regime. Shortly after sheet flow, wetting ability reaches saturation. As for increasing the inlet aperture, the flow pattern needs to be considered. Wetting ability increases first and then decreases under columnar flow, but the variation is relatively small. When flow pattern is transformed into columnar-sheet flow or sheet flow, liquid wetting ability will fall. Under the condition of a certain flow rate, the larger the diameter is, the larger the wetting area of the liquid film is, but the worse the wetting ability is. When the experimental tube is not horizontally placed, the change regulation of wetting length is no longer symmetrical with the liquid inlet column, but the lower part is stronger and the upper part is weaker. Reference | Related Articles | Metrics Select Numerical Simulation of Concentration Field of Liquid-Liquid Two-phase Impinging Streams in Submerged Condition Jianwei ZHANG Bowen SHI Ying FENG Zhigang ZHANG Chin. J. Process Eng.    2018, 18 (1): 57-62.   DOI: 10.12034/j.issn.1009-606X.217219 Abstract （877）      PDF （2141KB）（412）       Knowledge map    Save The numerical simulation of water and toluene two-phase impinging stream was performed by Fluent software to investigate the characteristics of concentration field of submerged liquid?liquid two-phase impinging stream. The concentration field of different sections was compared and analyzed by non-uniformity coefficient. The variation rules of concentration fields under different inlet flow rates (Q), inlet diameters (D) and two nozzle spacings (L) were obtained. The results showed that the non-uniformity coefficient increased first and then decreases with the increase of inlet flow rate. When Q=300 and 800 L/h, the non-uniformity coefficient was less than 0.04. With the increase of two nozzle spacing, the non-uniformity coefficient continued to increase. The non-uniformity coefficient was less than 0.05 when L≤3D. This phenomenon showed that liquid?liquid two-phase impinging stream had well mixing effect with small nozzle spacing. With nozzle diameter increasing, non-uniformity coefficient increased firstly and then decreased with the best value at D=10 mm. Reference | Related Articles | Metrics Select Powder Mixing Performance in Stirred Tanks with Combined Agitators Junxi LIU Zhengming GAO Boxue MA Yuyun BAO Ziqi CAI Chin. J. Process Eng.    2018, 18 (1): 63-68.   DOI: 10.12034/j.issn.1009-606X.217232 Abstract （866）      PDF （533KB）（243）       Knowledge map    Save Four different helical ribbon impeller combinations were used to study the powder mixing in a stirred tank with diameter of 0.48 m. The effects of rotation speed, powder filling level, impeller combination on the mixing performance, and the powder mixing performance at the axial and radial cross were investigated. The results showed that the rotational speed was the important factor of effect the powder mixing. The mixing factor π3 at rotational speed of 44 r/min fell by 30% and 50% than the speed was 26.5 and 8.7 r/min. The extra small impeller installed inside the big impeller could increase the power consumption, but significantly reduce the mixing factor π3 50% at the rotation speed of 44 r/min, enhanced the mixing performance. Reference | Related Articles | Metrics Select Influencing Factors on Distribution of Pressure Pulsation Intensity in Injection Zone of a Novel FCC Riser Fengjing ZHAO Jing BIAN Yiping FAN Chin. J. Process Eng.    2018, 18 (1): 69-74.   DOI: 10.12034/j.issn.1009-606X.217236 Abstract （776）      PDF （393KB）（261）       Knowledge map    Save The axial and radial distributions of pressure pulsation intensity in a catalyst-feed counter-current contacting injection zone were studied in a large-scale cold model experiment. Combined the distributions of pressure pulsation intensity with the concentration distributions of the feed jets, the pre-lift gas and the particles, the gas?solid interaction characteristics as well as the influence of the pressure pulsation on the flow patterns were analyzed. The results showed that based on the contributions of the feed jets, the pre-lift gas and the particles, the whole feed injection zone can be divided into three parts, the jet gas upstream influence zone (H=?0.375~?0.1 m), the jet gas controlling zone (H=?0.1~0.375 m) and the jet gas downstream influence zone (H=0.375~0.675 m). The simulation results of radial distribution of relative standard deviation of pressure pulsation in the injection zone agree well with the experimental data. Reference | Related Articles | Metrics Select External Mass Transfer Coefficient of Caprolactam in Nylon 6 in Liquid-Solid Extraction Tower Chunxi QIN Zhenhao XI Ling ZHAO Chin. J. Process Eng.    2018, 18 (1): 75-81.   DOI: 10.12034/j.issn.1009-606X.217261 Abstract （776）      PDF （337KB）（512）       Knowledge map    Save The liquid?solid extraction process of caprolactam (CL) in nylon 6 particles was investigated by packed bed semi-continuous experiments under the conditions of industrial interest. Based on the assumption that the CL concentration profile inside particles conformed to parabolic profile during the extraction, the external mass transfer coefficient model was developed. The results showed that in the range of temperature 65~95℃ and liquid velocity 0.27~2.71 mm/s, the liquid?solid extraction process of CL could be significantly accelerated by the increase of either temperature or liquid velocity. The external mass transfer coefficient model was adapted to reproduce the experimental data under the dimensionless time larger than 0.15. Through normalizing the external mass transfer coefficients, a correlation of Sh, Sc and Re, which could be used to predict the CL external mass transfer coefficient in the industrial extraction tower, was acquired. Reference | Related Articles | Metrics Select Efficient Recovery of Dichloromethane by [Bmim][PF6] and Process Simulation Binqi WANG Xiangping ZHANG Dawei SHANG Jianpeng FENG Hui WU Yanchun ZHANG Jianwei LI Chin. J. Process Eng.    2018, 18 (1): 82-87.   DOI: 10.12034/j.issn.1009-606X.217196 Abstract （1044）      PDF （461KB）（551）       Knowledge map    Save The solubility of dichloromethane (CH2Cl2) in ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) at different temperatures and pressures was measured by intelligent gravimetric adsorption instrument. The NRTL equation was applied to describe the vapor?liquid equilibrium of IL?CH2Cl2 system and the thermodynamic interaction parameters were regressed with experimental data. The calculated properties agreed well with experimental data, and the average relative deviation was 3.16%. Based on the results, the absorption and recovery process model of waste gas containing dichloromethane by ionic liquid solvent was established, the applicable range of the model were temperature of 278.15~308.15 K and pressure of 0~0.1 MPa, while the absorption at normal pressure and vacuum flashing for the recovery of CH2Cl2 was proposed. The operating parameters of the absorption tower were analyzed by simulation method, which provided which provided the optimum data at normal temperature and pressure. Reference | Related Articles | Metrics Select Impact of Heating Rate on Desorption Performance of CO2 Attached to 13X Zeolite Yalou GUO Hui ZHANG Yingshu LIU Ziling ZHAO Xuankai ZHANG Dong LI Chin. J. Process Eng.    2018, 18 (1): 88-95.   DOI: 10.12034/j.issn.1009-606X.217229 Abstract （1113）      PDF （550KB）（836）       Knowledge map    Save Temperature programmed desorption (TDP) was used to investigate the impact of heating rate on desorption performance of CO2 attached to 13X zeolite. Based on the Polanyi?Wigner equation, the desorption activation energy Ed under different heating rates was calculated without any assumed conditions. The results showed that two desorption peaks on TPD curve were produced while heating 13X molecular sieve full of CO2 at room temperature, one was located at low temperature, called as low-temperature peak, the other was at high temperature, called as high-temperature peak. Ed changed with ?. The low-temperature peak related to the desorption activation energy Ed,L decreased logarithmically with respect to increasing ?, while Ed,H remained the same, and the value of Ed,L was smaller than that of Ed,H. So Ed calculated without assumptions were more reasonable and accurate than the value calculated by variable heating rate method. For the same adsorption capacity, desorption capacity of CO2 called Qd,L at low temperature increased gradually with the growth of ?, while Qd,H at high temperature decreased, and Qd,L was far greater than Qd,H. The different acting force of physisorption and chemisorption was the key factor that resulted in a difference between high-temperature peak and low-temperature peak on adsorption mechanism. Reference | Related Articles | Metrics Select Separation Mechanism of Solid/Liquid Inclusions Transfer at Steel?Slag Interface Yelian ZHOU Zhiyin DENG Miaoyong ZHU Chin. J. Process Eng.    2018, 18 (1): 96-102.   DOI: 10.12034/j.issn.1009-606X.217237 Abstract （961）      PDF （5894KB）（550）       Knowledge map    Save Some physical simulation experiments were carried out to understand the phenomenon that solid inclusion could be removed more easily compared with liquid inclusions in industrial practice. The results showed that the molten steel between a solid inclusion and the interface would be drained out by the interfacial tension in an extremely short time since the solid inclusions cannot be wetted by liquid steel. Subsequently, solid inclusions can enter the slag phase immediately. On the other hand, liquid inclusions can be wetted by liquid steel and the liquid steel between the inclusion and interface cannot be drained out by the interfacial tension, then a thin steel film would form. The pressure in liquid film would finally break the film, resulting in the separation of liquid inclusions. The residence time of liquid inclusions at the steel?slag interface was obviously longer than that of solid inclusions in a real case. Reference | Related Articles | Metrics Select Extraction of Zinc from Zinc Ammonia Solution by M5640 Ziyu ZHUANG Chang WEI Xingbin LI Hui HUANG Xingguo LUO Zhigan DENG Cunxiong LI Chin. J. Process Eng.    2018, 18 (1): 103-110.   DOI: 10.12034/j.issn.1009-606X.217268 Abstract （943）      PDF （439KB）（814）       Knowledge map    Save Zinc was extracted from ammonia?ammonium sulfate solution using M5640 as an extractant. By the synergistic effect of CO2, the effects of extractant concentration, total ammonia concentration, phase ratio, temperature and addttion CO2 on the extraction rate of zinc were examined. The results showed that M5640 had a certain extraction ability to zinc from ammonia solution, and the pH value of solution and total ammonia concentration had obvious influence on the extraction rate of zinc. In the extraction process, add CO2 into solution can obviously improve the extraction efficiency of zinc. Under the conditions of temperature 25℃, M5640 concentration 35vol% O/A phase ratio of 2, zinc concentration 18.02 g/L, the total ammonia concentration in the solution 3 mol/L, with addition of CO2, zinc extraction rate increased from 65.1% (without CO2) to above 97%, by two stage cross-current extraction, zinc extraction rate reached 99.9%. The organic phase without ammonia, the results indicated that addition of CO2 can avoid co-extraction ammonia. Reference | Related Articles | Metrics Select Influence Factors and Kinetics of Vanadium Precipitation for the Vanadium Solution from Calcified Vanadium Extraction Juhua ZHANG Zhefeng YAN Li ZHANG Chin. J. Process Eng.    2018, 18 (1): 111-117.   DOI: 10.12034/j.issn.1009-606X.217138 Abstract （907）      PDF （849KB）（508）       Knowledge map    Save Vanadium component was precipitated and concentrated by ammonium salt from the acidic vanadium solution obtained by the process comprising of calcium roasting, dilute acid leaching and chemical precipitation purification. The effects of concentration of vanadium, the initial pH of solution, adding amount of ammonium, temperature and time on precipitation rate and quality of vanadium pentoxide were studied and the kinetics of vanadium precipitation was analyzed. The precipitates were characterized. The results showed that under the conditions of initial pH of 2.00?0.05, molar ratio of NH3 to V being 1.5, temperature higher than 95℃, reaction time of 120 min and concentration of vanadium larger than 20 g/L, precipitation rate was higher than 96%, the content of V2O5 in the final product is over 98%, and the contents of impurities meet the standards of Grade 98 vanadiumpentoxide. Avrami kinetic equation well describes the precipitation process occurring at 75?99℃ with apparent activation energy Ea=93.23 kJ/mol and pre-exponential factor A=9.14×1011 min?1. The vanadium precipitate is (NH4)2V6O16?1.5H2O. The crystal of vanadium pentoxide exists in columnar with mean size of 1.25 ?m, and the main impurity of Mn appears as MnV2O6. Reference | Related Articles | Metrics Select Sodium/Potassium Precipitation Behavior during Evaporative Crystallization of Ammonium Paratungstate from Ammonium Tungstate/Nitrate Solution Qiusheng ZHOU Dong LI Zhicheng ZHU Xiaobin LI Tiangui QI Chin. J. Process Eng.    2018, 18 (1): 118-125.   DOI: 10.12034/j.issn.1009-606X.217153 Abstract （895）      PDF （378KB）（273）       Knowledge map    Save The effect of several factors, including the amount of ammonium nitrate added, mass ratio of sodium/potassium to tungsten, and reaction temperature, on the precipitation of sodium/potassium during Evaporative Crystallization of Ammonium Paratungstate from ammonium tungstate/ammonium nitrate solution system were investigated. The results showed that sodium/potassium paratungstate was precipitated more readily than ammonium paratungstate (APT). Further, the precipitation of sodium/potassium can be inhibited by adding ammonium nitrate during the crystallization of ammonium paratungstate from the ammonium tungstate solution. The inhibitory effect of ammonium nitrate on the precipitation of sodium/potassium increases with the ammonium nitrate concentration. The sodium/potassium content in the precipitate decrease with a increases of the crystallization temperature and an decrease of sodium/potassium content in the solution. The sodium/potassium content in APT can be less than the recommended limit when concentration of ammonium nitrate is 20 g/L, concentration of initial sodium was 0.100 g/L, initial concentration of potassium was 0.030 g/L, and crystallization temperature was 95℃. Reference | Related Articles | Metrics Select Preparation of Large-sized Scorodite Based on Arsenic and Iron Hydrothermal Co-precipitation Zixiu YU Cunxiong LI Chang WEI Gang FAN Xingbin LI Zhigan DENG Minting LI Chin. J. Process Eng.    2018, 18 (1): 126-132.   DOI: 10.12034/j.issn.1009-606X.217178 Abstract （808）      PDF （1496KB）（301）       Knowledge map    Save Coprecipitation of arsenic and iron in sulphuric acid system to produce large particle sized scorodite was carried out. The effects of initial Fe/As molar ratio, initial pH, temperature, agitation speed and oxygen partial pressure on scorodite crystalline formation, particle size distribution and the precipitation rates of As and Fe were investigated. The results showed that the decrease of Fe/As molar ratio, initial pH and temperature was beneficial to large and purified scorodite formation which was independent of oxygen partial pressure. Higher agitation speed was available for the formation of more purified scorodite but small-sized scorodite. The precipitation of As was higher than 97%, the content of arsenic in residue was larger than 30% and the average size of scorodite was larger than 20 ?m under the optimum conditions of Fe/As molar ratio 1.5, initial pH 1.0, temperature 160℃, agitation speed 500 r/min, oxygen partial pressure 0.4 MPa. Reference | Related Articles | Metrics Select The Effect of Additives on the Preparation of Reduced Iron Powder from Iron Concentrate Yuxin CAO Henghui WANG Jianghua MA Dong ZHAO Guangqiang LI Chin. J. Process Eng.    2018, 18 (1): 133-139.   DOI: 10.12034/j.issn.1009-606X.217190 Abstract （800）      PDF （1497KB）（278）       Knowledge map    Save The effect of additives (CaO, Na2CO3, Na2SO4) on the preparation of reduced iron powder from iron concentrate containing 70.25% Fe and 1.86% SiO2 was investigated. The thermodynamics calculation of the reactions between additives and ferrous silicate (Fe2SiO4) was analyzed. The optimum additive is CaO deduced from the thermodynamic analysis for the beginning temperature of reaction is the lowest of 650 K. Then the effects of additives on the preparation of reduced iron powder were investigated by the experiment: two-step carbon-hydrogen reduction of iron concentrate at 1423 K. The results indicated that adding Na2CO3 increased the T. Fe content of the reduced iron powder to 98.32%. Adding CaO dropped the T. Fe content to 93.27%, and the SiO2 content was declined to 1.65%. The additive (CaO) can inhibit the formation of Fe2SiO4, but a new phase (3CaO?SiO2) which was composite of Ca and Si was wrapped in metallic iron. The wrapped structure contributed to the hard removal of Si. Reference | Related Articles | Metrics Select Influences of Temperature and Residence Time on Secondary Reactions of Volatiles from Coal Pyrolysis Qimeng DUN Zhaohui CHEN Fulin HUANG Yang ZHOU Jian YU Shiqiu GAO Hongyan LIU Chin. J. Process Eng.    2018, 18 (1): 140-147.   DOI: 10.12034/j.issn.1009-606X.217192 Abstract （884）      PDF （472KB）（259）       Knowledge map    Save The influences of temperature and residence time on secondary reactions of coal pyrolysis volatiles were investigated in a dual-stage fixed bed reactor. The results showed that the effects of temperature and residence time on secondary reactions are closely related. The secondary reactions of volatiles hardly occurred in general at the secondary reaction temperature≤600℃ and under residence time 2 s. The tar yield decreased while corresponding gas and deposited carbon yields increased by increasing temperature and residence time due to the intensified secondary reaction of volatiles. At lower temperature (below 700℃), the tar mainly converted into gas product by secondary cracking of tar. At higher temperature (above 700℃), the tar transformed into gas and deposited carbon products by the secondary cracking and coking of tar. With the increase of the temperature and the residence time of secondary reactions, the yields of H2, CH4 and CO increased while CO2 yield decreased, and also lead to the increase of the heavy PAHs (polycyclic aromatic hydrocarbons of more than 3 ring) and the decrease of the phenol, cresol, xylenol and atom ratio of H/C and O/C. Especially at 900℃, the yields of H2 and heavy PAHs increased rapidly with increasing the residence time, due to the occurrence of the violent condensation reactions among aromatic rings. Reference | Related Articles | Metrics Select Deeply Removing Sodium by Hydrothermal Method in the Process of Preparing High Pure Alumina from Bayer Liquid Ying WANG Xiaohua YU Pan FENG Shuanglin YU Huixian SHI Gang XIE Chin. J. Process Eng.    2018, 18 (1): 148-153.   DOI: 10.12034/j.issn.1009-606X.217205 Abstract （913）      PDF （2539KB）（444）       Knowledge map    Save High pure alumina was prepared using Bayer liquid. Gibbsite was treated by hydrothermal method under different conditions, then the impurity of sodium re-dissolved in water. Physical and chemical properties of the hydrothermal product were analyzed. The results showed that raising hydrothermal temperature to 180℃, gibbsite changed into boehmite. Na2O returned to dissolution in water during the transformation process of gibbsite, rising temperature and decreasing pH could promote the transformation, prolonging the reaction time could extend reaction, boehmite`s morphology, liking "broken glass" shape, was hugely different from gibbsite after the hydrothermal treatment. Compared with gibbsite, the boehmite was looser and more unordered. Under the condition of pH=1, the content of Na2O in hydrothermal production was as low as 0.0163wt%, which can reduce to 0.0187wt% after calcination at 1200℃. Related Articles | Metrics Select Highly Enhanced Infrared Emissivity of Perovskite LaFeO3 by Ca2+ Doping Zhao HAN Pengfei LIU Xiaowei LI Weihua LU Chin. J. Process Eng.    2018, 18 (1): 154-158.   DOI: 10.12034/j.issn.1009-606X.217209 Abstract （824）      PDF （561KB）（382）       Knowledge map    Save Pure LaFeO3 and Ca2+-doped LaFeO3 ceramics were prepared by solid-state reaction in air atmosphere, and their near-infrared (NIR) emissivity characteristics were investigated and compared with each other. The results revealed that 10mol% Ca2+-doped LaFeO3, namely La0.9Ca0.1FeO3, exhibited a NIR emissivity as high as 0.92 in the wavelength region of 3?5 ?m, which was 119% higher than that of pure LaFeO3. The reason was Ca2+-doped LaFeO3 mainly attributed to the electronic transition absorption of Fe3+?Fe4+ small polarons introduced by Ca2+ doping. Reference | Related Articles | Metrics Select Preparation of Biomass Granular Activated Carbon with K2CO3 and Sycamore Tree Sawdust via Dry Mix Process Peiyong MA Jinzhou WU Xianwen ZHANG Xianjun XING Xiaowei GUO Chin. J. Process Eng.    2018, 18 (1): 159-164.   DOI: 10.12034/j.issn.1009-606X.217218 Abstract （834）      PDF （521KB）（164）       Knowledge map    Save The granular activated carbon particles were produced by dry mix method with the sycamore tree sawdust and K2CO3. The influences of salt/sawdust mass ratio, activation temperature, activation time and granular density on the granular activated carbon adsorptive property were investigated. The results indicated that the optimal preparation conditions for making granular activated carbon were mass ratio of salt to sawdust 2.0, activation temperature 950℃, activation time 60 min and granular density 1.3 g/cm3, where the granular activated carbon obtains the best iodine adsorption capacity (1323.25 mg/g). The granular activated carbon has the developed pore structure and large specific surface area (1432.59 m2/g), the total pore volume is 0.772 cm3/g, and the average pore diameter is 1.7 nm. Particularly, the micro-pore specific surface area as well as 1302.75 m2/g and pore volume 0.566 cm3/g respectively, microporous rate reached 73.3%. Reference | Related Articles | Metrics Select Homogeneity of Solid Si Particle Oxidation in Na 2O-CaO-SiO 2 Porous Glass-ceramics Mingming YAN Jianwei CAO Zhi WANG Guohua LI Chin. J. Process Eng.    2018, 18 (1): 165-170.   DOI: 10.12034/j.issn.1009-606X.217223 Abstract （731）      PDF （1193KB）（208）       Knowledge map    Save Addition solid Si particle as bubbe nucleation spots to adjust the pore structure of Na2O?CaO?SiO2 (NCS) porous glass-ceramics, the oxidation behavior of Si in NCS porous glass-ceramics was studied, its effect on the thermal field distribution of NCS porous glass-ceramics was simulated by ANSYS model. The results showed that the oxidation of solid Si particle started at 650℃ in NCS porous glass-ceramics, and the thermal field distribution of NCS porous glass-ceramics gets uniform with the addition of solid Si particle, so that the oxidation degree of solid Si particle in NCS porous glass-ceramics are same, it won?t affect the pore size distribution of NCS porous glass-ceramics. Reference | Related Articles | Metrics Select Application of Adjustable Gradient Mobile Phase Control System on Biomacromolecule Characterization Cui SONG Jia GE Xiunan LI Qiang LI Chao CHEN Peng WANG Guanghui MA? Chin. J. Process Eng.    2018, 18 (1): 171-176.   DOI: 10.12034/j.issn.1009-606X.217230 Abstract （781）      PDF （391KB）（316）       Knowledge map    Save Based on the syringe pumps and cooperated with the developed software, an adjustable gradient mobile phase control system was developed, furthermore the system was connected with quartz crystal microbalance (QCM). Through the gradient adjustion of salt concentration or pH value, the real time adsorption and elution variations of bovine serum albumin (BSA) were investigated. The results showed that the flow error was 1%, the flow stability was 1%, and the gradient error was 1%, which met the standard of GB/T 26792-2011. With the increase of salt concentration or decrease of pH value, the BSA was eluted gradually. These results demonstrated that this system could regulate the gradient and simulate complicated solid?liquid interface environment accurately. Reference | Related Articles | Metrics Select Preparation of Low Carbon Pure Ferrochromium from High Carbon Ferrochromium by Molten Salts Electrorefining Wei LIU Guolong LIU Meichen WANG Saijun XIAO Chin. J. Process Eng.    2018, 18 (1): 177-181.   DOI: 10.12034/j.issn.1009-606X.217235 Abstract （821）      PDF （961KB）（368）       Knowledge map    Save Low carbon ferrochromium was prepared from high carbon ferrochromium in NaCl?KCl molten salts by one-step potentiostatic electrolytic refining (0.3 V, vs. Ag/AgCl), with high carbon ferrochromium acted as working electrode, tungsten acted as counter electrode and Ag/AgCl as reference electrode. The mechanism of electrodeposition of dissolved Cr ions was investigated by square wave voltammetry. Microscopic and phase characterization of cathodic products were analyzed. The results showed that the reduction of chromium ions is a one-step reversible process with two electrons exchanged, which is controlled by diffusion mass transfer, and chromium was dissolved prior to iron in molten salts. The produced low carbon ferrochromium is mostly composed of spherical particles with the size ranging from 0.5 to 2 ?m. The carbon content of the cathode product was 0.24wt%. Reference | Related Articles | Metrics Select Potential of Mean Force between CO2 and CH4 in Typical Ionic Liquid Systems by Molecular Dynamics Simulation Zhe CUI Yandong GUO Feng HUO Xiaodong XIE Chin. J. Process Eng.    2018, 18 (1): 182-189.   DOI: 10.12034/j.issn.1009-606X.217245 Abstract （912）      PDF （421KB）（227）       Knowledge map    Save The microscopic structure of ionic liquids (ILs) [Emim][Tf2N], [Emim][BF4], [Bmim][Tf2N] and [Bmim][BF4] around gas molecules CO2/CH4 was obtained by analyzing radial distribution functions from molecular dynamic (MD) simulation. In addition, the potential of mean force (PMF) of CO2 and CH4 molecular pairs in the four systems were calculated respectively by weighted histogram analysis method under different umbrella sampling with MD simulation. The results showed that the potential well of CO2 in [Bmim][Tf2N] is the deepest in the four types of ILs. The indicator from PMF curves in molecular level is consistent with the solubility in experiment. The PMF indicator plays an important role in choosing proper cations and anions to design the specific ILs for gas separation. Reference | Related Articles | Metrics Select Preparation of Hollow Porous LiMn2O4 Cathode Materials Bing QIAN Xiumei SONG Junwei YUE Qingqing LIU Yaxin SUN Chin. J. Process Eng.    2018, 18 (1): 190-195.   DOI: 10.12034/j.issn.1009-606X.217207 Abstract （823）      PDF （1637KB）（401）       Knowledge map    Save Hollow porous LiMn2O4 particles (PLMO) were prepared by sol?gel method using carbon spheres as template, carbon spheres were obtained by hydrothermal method. The effects of calcination temperature and the addition amount of carbon spheres on the phase formation and surface morphology were studied. The electrochemical properties of PLMO and LiMn2O4 without adding carbon spheres (LMO) were investigated. The results indicated that the honeycomb porous LiMn2O4 hollow particles were obtained at 650?750℃ for 12 h. At discharge rate 0.5C, the discharge capacity of PLMO decreased from 126 mA?h/g to 111 mA?h/g after 50 cycles, which are higher than that of LMO. At 5C discharge rate, the initial discharge capacity of PLMO is 89 mA?h/g, which is increased by about 39% compared with LMO. Reference | Related Articles | Metrics Select Estimation of Thermal Conductivity of Liquid Aromatic Hydrocarbons Using Finite Element Analysis Method in Molecular Structure Minghua QIU Wanqiang LIU Fengping LIU Guanfan CHEN Ming YUE Chin. J. Process Eng.    2018, 18 (1): 196-201.   DOI: 10.12034/j.issn.1009-606X.217220 Abstract （688）      PDF （353KB）（218）       Knowledge map    Save The 3D molecular structure of aromatic hydrocarbon was analyzed by finite element analysis to establish the stiffness matrix and vibration equation, from which nature frequency and stiffness matrix eigenvalues are calculated with MATLAB software, then QSPR model for the conductivity of liquid aromatic hydrocarbons was developed by multivariate regression method, and further performing optimization, mean value and D-value treatment on the model. The results showed that for training set (301 liquid aromatic hydrocarbons), the correlation coefficient between the results calculated by QSPR model and the experimented data is 0.979, the mean absolute error is less than 0.0024 W/(m?K), the relative error is less than 2.02%, for test set (22 liquid aromatic hydrocarbons), the correlation coefficients is 0.978, the mean absolute error is less than 0.0028 W/(m?K), the relative error is less than 2.99%. Reference | Related Articles | Metrics Select Preparation of Bismuth Vanadate Yellow Pigments by Homogeneous Reaction Method Xuemei GUO Shaona WANG Yao NIE Hao DU Shili ZHENG Yi ZHANG Chin. J. Process Eng.    2018, 18 (1): 202-209.   DOI: 10.12034/j.issn.1009-606X.217225 Abstract （820）      PDF （3495KB）（412）       Knowledge map    Save BiVO4 with different structures and morphologies was synthesized by homogeneous reaction method using Bi(NO3)3?5H2O and NH4VO3 as materials. The effects of molar ratio of Bi to V, pH value, temperature and stirring speed of homogeneous reactor on the particle size, morphology and chroma of BiVO4 were investigated. BiVO4 samples were characterized. The results revealed that homogeneous reaction method helps preparing size and morphology uniformity BiVO4. The optimum conditions of synthesizing BiVO4 were molar ratio Bi/V=1, pH=7, temperature 105℃, reaction time 6 h and stirring speed 60 r/min. Adding surfactants can get more morphology of bismuth vanadate, which is conducive to the further application of bismuth vanadate. Related Articles | Metrics Select Analysis and Application of Broken Theory in the Process of Coke Degradation Qihang LIU Yanan ZHANG Keng WU Chin. J. Process Eng.    2018, 18 (1): 210-217.   DOI: 10.12034/j.issn.1009-606X.217211 Abstract （807）      PDF （796KB）（416）       Knowledge map    Save A power consumption equation for coke degradation was established based on the two kinds of quintessential volume hypothesis which was the theory about energy-size of comminution. The effect of gasification reaction and temperature on energy consumption of coke degradation was analysed by gasification and high temperature compressive experiments. The energy conversion between the external mechanical work and internal energy of cokes was analyzed by high temperature compressive experiments, and then the parameter of temperature was introduced into the power consumption equation. The degradation rate of gasified coke at different temperatures were predicted by the improved power consumption equation. The results showed that the coke degradation rate was significantly affected by the input power which has a greater impact on the more reacted cokes, and the drum experiment was conducted to verify the applicability of power consumption equation for gasified coke degradation at room temperature. The temperature has a significant influence on the coke degradation behavior, and the more input power for the system, the greater the influence of temperature on the gasified coke degradation. Reference | Related Articles | Metrics Select Effects of Swelling on Structure, Composition and Pyrolysis Behavior of Xinjiang Naomaohu Coal Yuan ZHAO Liming HUANG Fengyun MA Mei ZHONG Chin. J. Process Eng.    2018, 18 (1): 218-224.   DOI: 10.12034/j.issn.1009-606X.217227 Abstract （776）      PDF （461KB）（284）       Knowledge map    Save Washing oil (WO), 2-methyinaphthalene (MN) and quinolone (QL) were selected as the swelling agent to treat Naomaohu coal sample. The effects of swelling on the physical and chemical structure of coal sample were study. The results showed that comparison with raw coal, volatile and carbon contents of swelling coal samples decreased, especially the carbon content decreased significantly, approximately 8.63%, while H and O contents indicated an increasing tendency. Methylene carbon in samples swelling using WO, MN and QL decreased 6.37%, 5.74% and 7.55% respectively, but carbonyl and carboxyl carbon increased to 10.60%, 11.40% and 11.10%. After swelling, over 30% of specific surface area was reduced, but their average pore size were enlarged. The decrease of surface free energy could be attributed to the arrangement of coal structure via swelling. Pyrolysis tar and gas yields of swelling coal were higher than raw coal, especially for H2 and CO yields. However, the inhibition of crosslinking reaction led to lower the CO2 yield. Reference | Related Articles | Metrics Select Cover and Contents Chin. J. Process Eng.    Select Study Progress in Modification of LiNi0.8Co0.15Al0.05O2 Cathode Material for High Energy Density Lithium Ion Batteries Shuangshuang ZHENG Libin MA Yanxia LIU Chin. J. Process Eng.    2018, 18 (2): 225-231.   DOI: 10.12034/j.issn.1009-606X.217244 Abstract （1074）      PDF （971KB）（338）       Knowledge map    Save LiNi0.8Co0.15Al0.05O2 has been regarded as the most promising cathode material for power lithium battery because of its high energy density and high cost efficient. However, some issues, such as safety performance, cyclic stability and high temperature performance, hindered its commercial application. The common ideas to enhance these properties including ion doping and surface coating. The modification of LiNi0.8Co0.15Al0.05O2 cathode materials is summarized in this paper, and also has prospect to the future research orientation. Related Articles | Metrics Select A Review of Treatment on Dihydric Phenol in Coal Chemical Wastewater Wenzhao LIU Gaojie XU Qiang DONG Pengge NING Yuping Li Chin. J. Process Eng.    2018, 18 (2): 232-240.   DOI: 10.12034/j.issn.1009-606X.217270 Abstract （827）      PDF （390KB）（162）       Knowledge map    Save The treatment technology on the wastewater containing dihydric phenol-contained from the coal chemical industry was summarized. The adsorption, emulsion liquid membrane, solvent extraction, incineration, phenolic condensation, chemical oxidation, steam phenol removal, ozone oxidation, advanced oxidation are compared respectively including their advantages, disadvantages and application prospect. Among them, the solvent extraction method was underlined through the selection of extractant and the analysis of influence factor. Besides, the research evolution and tendency of the treatment technology on the dihydric phenol-contained wastewater was further prospected especially. The multi-technology combination would be a hot spot. Related Articles | Metrics Select 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 （902）      PDF （779KB）（609）       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 Select Simulation of Axial Solid Holdup in Slurry Bubble Columns Shuzhou SHI Rongtao ZHOU Ning YANG Jianfei SONG Chin. J. Process Eng.    2018, 18 (2): 258-264.   DOI: 10.12034/j.issn.1009-606X.217238 Abstract （903）      PDF （384KB）（151）       Knowledge map    Save DBS drag model for gas?liquid interaction, and three drag models for liquid?solid interaction including Gidaspow model, Gidaspow?Brucato model and Schiller?Naumann model were used to simulate slurry bubble columns without considering the direct interaction between gas and solid. The simulation and experimental results of axial solid holdup with different particle sizes were compared. The results showed that different liquid?solid drag models had minor influence on the prediction of gas holdup. The combination of DBS drag model and Schiller?Naumann model had a better prediction for the systems of larger particle size (140 ?m) at lower gas velocity. The solids holdup decreased with increasing the column height, whereas other models fail to predict the axial solids holdup distribution. These different liquid?solid drag models performed well for the systems of smaller particle size (35 ?m). Reference | Related Articles | Metrics Select Three-dimensional Modelling of Pulverized Coal Injection in Blast Furnace Raceway Tian CHEN Shusen CHENG Chin. J. Process Eng.    2018, 18 (2): 265-273.   DOI: 10.12034/j.issn.1009-606X.217262 Abstract （931）      PDF （2253KB）（335）       Knowledge map    Save A three-dimensional mathematical model including gas?solid flow, radiation and coal combustion was established to simulate the pulverized coal injection in blast furnace raceway. With the help of commercial software, the flow field, temperature field and composition change in the raceway were simulated. The results showed that the flow pattern can be divided into two parts: a high-speed jet along the tuyere direction and a large-scale recirculation at the upper part of the raceway. The distributions of temperature field was not uniform, and the temperature was higher at the lower part of raceway and the heat transmits to the upper part along the boundary of the raceway. Oxygen was consumed constantly along the tuyere axis. The carbon dioxide content increased with the decrease of oxygen content and reached the maximum when the oxygen was almost exhausted. Then, the carbon monoxide content increased rapidly with the carbon dioxide content decreased. The increase of blast oxygen enrichment, blast temperature and blast rate can promote the combustion of pulverized coal and increase the burning speed of pulverized coal. Reference | Related Articles | Metrics Select Experimental Research on Forced Convective Heat Transfer Titanium Alloy Twisted Tube Xinyu DONG Qincheng BI Miao GUI Chin. J. Process Eng.    2018, 18 (2): 274-279.   DOI: 10.12034/j.issn.1009-606X.217290 Abstract （861）      PDF （543KB）（280）       Knowledge map    Save An experimental study with the deionized water was conducted on the heat transfer and flow resistance properties in the internal of the titanium alloy twisted tube. A comparison with the same specification of ordinary tube was carried out. The correlation equations with the Nusselt number and the resistance coefficient were given respective by according to the results of experiment. By comparing with the classical correlations, results showed that heat transfer correlations of transition flow and turbulent flow in a titanium alloy twisted tube were obtained and good agreement was observed between the experimental data and the classical correlations presented by Dittus?Boelter, Sieder?Tate, Михеев and Gnielinski equations, respectively. Reference | Related Articles | Metrics Select Numerical Simulation of Radiation Heat Transfer in SiC Crystal Growth Furnace Chunzhen YANG Guangxia LIU Chengmin CHEN Min XU Liqiu WANG Chin. J. Process Eng.    2018, 18 (2): 280-287.   DOI: 10.12034/j.issn.1009-606X.217295 Abstract （1014）      PDF （2551KB）（501）       Knowledge map    Save Three dimensional numerical simulation platform for SiC crystal growth furnace was established based on C programing language, where physical model of the furnace was built based on cylindrical coordinate, governing equations for electromagnetic and temperature fields were discretized by finite volume method, and radiation characteristic was studied with the help of S2S (Surface to Surface) radiation model. The least distance method was developed, which was used to check whether radiation surfaces were visible with each other or not efficiently. And then the radiation heat transfer in SiC growth chamber and temperature field of SiC growth furnace were studied quantificationally when the current intensity is 1250 A and the current frequency is 16 kHz. The effects of coil structures on crystal temperature field and its gradient distributions were studied by standard deviation method. The results showed that spiral electromagnetic coil generated asymmetrical temperature field easily. The radiation heat flux was 102~103 more than conduction heat flux. The radiation was helpful to increase temperature evenness. The spiral temperature field on the SiC crystal cross-section reduced the poor homogeneity of temperature gradient, which made the crystal to generate large thermal stress. Reference | Related Articles | Metrics page Page 1 of 6 Total 212 records First page Prev page Next page Last page