Table of Content

20 April 2016, Volume 16 Issue 2

Previous Issue    Next Issue

Analysis on Flow Field of Hydrocyclone Separation Based on Four-parameter Rheological Model

LIU Hong-bin XIAO Hui-na LI Ping-ying MO Wei-tao

Chin. J. Process Eng.. 2016, 16(2):  181-188.  DOI: 10.12034/j.issn.1009-606X.215324

Asbtract ( )   PDF (383KB) ( )  

Related Articles | Metrics

A four-parameter rheological model was used to describe the non-Newtonian flow characteristics of drilling fluid, combining with Reynolds stress model, the influence of non-Newtonian behavior on the flow field of hydrocyclone separation was examined, and the distributions of velocity and pressure fields of three kinds of fluid were obtained. The results showed that the flow field simulation results were in accordance with the previous experimental results, indicating that the simulation was were reliable. Their fluid flow field distributions were similar, but at the same position, the static pressure (4.02 and 3.77 MPa) and axial velocity (11.9 and 12.4 m/s) of non-Newtonian fluid were greater than those of Newtonian fluid water (3.22 MPa and 11.7 m/s), and the tangential velocity of non-Newtonian fluid (42.5 and 39.7 m/s) was less than that of Newtonian fluid water (47.5 m/s). Compared with power law fluid, the static pressure of four-parameter rheological fluid decreased from 4.02 to 3.77 MPa and the pressure drop from 4.79 to 4.51 MPa, the energy loss was reduced by 0.28 MPa, while the tangential velocity was decreased by 2.8 m/s and the envelope of zero vertical velocity was closer to the wall, which was not conducive to the separation of fluid media.

Effect of Composition on Viscosity of CaO-Al2O3-SiO2-TiO2-MgO-Na2O System Slag

TONG Zhi-fang QIAO Jia-long CHEN Tao

Chin. J. Process Eng.. 2016, 16(2):  189-196.  DOI: 10.12034/j.issn.1009-606X.216021

Asbtract ( )   PDF (345KB) ( )  

Related Articles | Metrics

The viscosity of CaO-Al2O3-SiO2-TiO2-MgO-Na2O system slag was measured at 1773 K under the molten reduction condition by the restricted mixture uniform design method. The regression equation between slag composition and viscosity was established using the partial least squares regression analysis. The effects of basicity (CaO/SiO2), MgO, TiO2, Al2O3 and Na2O on the viscosity of slag were analyzed by the regression equation with relevant phase diagrams, literature and XRD phase analysis method. The results indicate that the correlation coefficient RC2 fitting to the regression model is 0.9945, indicating good agreement of the experimental data with the regression model, which can predict well the viscosity of slag. In the experimental composition ranges, the viscosity increase with increasing of basicity [w(CaO)/w(SiO2)]. When the basicity is fixed, the viscosity decreases with increasing of the contents of MgO, Al2O3 and Na2O. With increasing of TiO2 content, the viscosity first increases and then decreases. When the basicity of slag is less than 3.1, the mass fraction of MgO more than 4%, that of Al2O3 more than 20%, that of TiO2 in 3.1%~6.1%, that of Na2O more than 0.75%, the viscosity of slag is less than 2Pa×s at 1773 K, which fully meets the requirements of actual industrial operation.

Numerical Simulation on Mixing Process of Rubber Powder with Asphalt in a Stirred Tank

AN Hai-chao YANG Ren-feng WANG Zhong-cai YANG Bo

Chin. J. Process Eng.. 2016, 16(2):  197-203.  DOI: 10.12034/j.issn.1009-606X.215305

Asbtract ( )   PDF (5311KB) ( )  

Related Articles | Metrics

The phenomena of floating, sinking, wall hanging and sticking in the mixing process of rubber powder and asphalt in a stirred tank were studied, the mixing tank model of rubber asphalt was established, and the mixing process inside the tank with solid-liquid two-phase numerically simulated in a unsteady state based on CFD software. The effects of the blade diameter, blade position, baffle and stirring speed on the mixing uniformity were analyzed. The results showed that the suitable size and position of blade were beneficial to the form of cyclic axial flow and reduction of steady flow. The installation of the baffle reduced the occurrence of tangential flow. The stirring speed did not affect the basic form of internal flow, but the suitable speed improved the mixing uniformity. In addition, the mixing uniformity matched up with the simulation results, and under the agitator parameters of blade diameter 800 mm, blade position 680 mm, blade width 100 mm, and rotational speed 280 r/min, the distribution of rubber particles after optimization was more uniform at the mixing uniformity of 0.24, which was in the complete off-bottom suspension, fitting well to the simulation results.

Experimental Study on the Effect of Interfacial Mass Transfer on Coalescence of Gas Bubble

SHEN Jian-biao WANG Li

Chin. J. Process Eng.. 2016, 16(2):  204-209.  DOI: 10.12034/j.issn.1009-606X.215404

Asbtract ( )   PDF (290KB) ( )  

Related Articles | Metrics

A two-bubble coalescence experimental system was set up to study the effect of interfacial mass transfer on coalescence process of gas bubbles with non-phase change N2 gas phase and volatile aqueous solutions of acetone and ethanol as liquid phase. The coalescence behavior was investigated under different volatile components, concentrations, bubbling frequencies and bubble diameters in the temperature range of 25~50℃. The results showed that because of the Marangoni effect induced by the interfacial mass transfer, the coalescence time decreased at first and then increased with increasing of temperature, the distribution of coalescence time was significantly increased at higher temperatures, and the coalescence percentage was now the best physical magnitude to describe the whole coalescence process. The coalescence percentage began to decrease when the temperature rose to a certain value and tended to be stable at a minimal value at higher temperatures, the minimal coalescence percentage decreased with increasing of aqueous solution concentration, and the intensity of Marangoni effect could be well quantified by the stabilizing index M. Doubling the bubbling frequency and bubble diameter would decrease the minimal coalescence percentage 50% and 67%, respectively.

Axial Distribution of Averaged Cross-sectional Solids Hold-up in an Annulus Fluidized Bed-Riser Coupled Reactor

WANG Zi-jian E Cheng-lin HUANG Shi-ping LU Chun-xi

Chin. J. Process Eng.. 2016, 16(2):  210-215.  DOI: 10.12034/j.issn.1009-606X.215341

Asbtract ( )   PDF (578KB) ( )  

Related Articles | Metrics

The axial distribution of solids hold-up in a large scale cold model annulus fluidized bed-riser coupled reactor was studied. The results showed that in the fluidized bed zone, the averaged cross-sectional solids hold-up ( ) decreased with increasing of superficial gas velocity. The riser zone could be divided into two zones, fully developed zone (3.91~6.81 m) and back-mixing zone (6.81~8.60 m), increased with increasing of superficial gas velocity. When the gas velocity was less than 0.7 m/s, the distribution of was uniform, when the gas velocity was greater than 0.7 m/s, in back-mixing zone increased. In the annulus discharging duct, under the influence of gas bypass, the flow was concurrent with the gravity field with increasing of fluid resistance. When the gas velocity was less than 0.75 m/s, the distribution of was uniform, when the gas velocity was greater than 0.75 m/s, disengaging occurred in the cone-shaped sections. On the whole, the distribution of in the annulus discharging duct was uniform, increased slightly with decreasing of height of the annulus discharging. The particles could complete the circular flow back into the fluidized bed through the annulus discharging duct smoothly. Furthermore, the empirical models for estimating the axial distribution of were established based on experimental data, which were in good agreement with the experimental data.

Kinetics of Roasting of High Aluminum Content Coal Fly Ash with Sodium Carbonate and Acid Leaching for Extraction of Aluminum

LIU Neng-sheng PENG Jin-hui ZHANG Li-bo LIN Jin

Chin. J. Process Eng.. 2016, 16(2):  216-221.  DOI: 10.12034/j.issn.1009-606X.215358

Asbtract ( )   PDF (383KB) ( )  

Related Articles | Metrics

High aluminum content coal fly ash (CFA) from Inner Mongolia was roasted with Na2CO3, and the roasted material leached by HCl solution for extraction of aluminum. The effects of roasting temperature and time, and mass ratio of Na2CO3 to CFA on the leaching rate of aluminum were examined. The process kinetics and mechanisms of roasting and acid leaching were analyzed. The results showed that at high roasting temperature, the reaction of mullite (Al6Si2O13) and SiO2 in CFA with Na2CO3 resulted in formation of NaAlSiO4, Al2O3 and Na2SiO3, which could be dissolved in HCl solution. After acid leaching, the leaching rate of aluminum reached more than 94.99%. The Crank-Ginstling-Braunshtein model could be used to correlate the experimental data of roasting process, and the apparent activation energy was calculated as 117.06 kJ/mol. The reaction rate was controlled by solid-film diffusion.

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

Asbtract ( )   PDF (247KB) ( )  

Related Articles | Metrics

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.

Synthesis and Leaching Behavior of Na4Ca3(AlO2)10

TIAN　Yong-pan PAN Xiao-lin YU Hai-yan TU Gan-feng

Chin. J. Process Eng.. 2016, 16(2):  228-232.  DOI: 10.12034/j.issn.1009-606X.216022

Asbtract ( )   PDF (269KB) ( )  

Related Articles | Metrics

Na4Ca3(AlO2)10 was synthesized at 1100~1250℃ with analytically pure reagents of CaCO3, Al2O3 and Na2CO3. The effects of leaching time, leaching temperature, liquid-to-solid ratio and concentrations of sodium carbonate and sodium hydroxide in solution on the leaching rate of Na4Ca3(AlO2)10 were examined. The results show that the purity of Na4Ca3(AlO2)10 roasted at 1200℃ for 30 min is over 90%. The alumina leaching rate can reach over 90% after its leaching at 40℃ for 10 min, when the concentrations of sodium carbonate and sodium hydroxide are 80 g/L and 18 g/L, respectively. The leaching rate can be more than 85% after its leaching at 60℃ for 15 min, when the concentration of sodium carbonate decreases to 30 g/L. Sodium hydroxide in the solution benefits the leaching process of Na4Ca3(AlO2)10. The leaching rate can be improved more than 10% when the concentration of sodium hydroxide is higher than 5 g/L. Na4Ca3(AlO2)10 has better leaching efficiency than 12CaO·Al2O3 and CaO·Al2O3.

Preparation of Iron Concentrate from Siderite by Magnetizing Roasting and Magnetic Separation

CHUN Tie-jun WU Xue-jian NING Chao LONG Hong-ming

Chin. J. Process Eng.. 2016, 16(2):  233-237.  DOI: 10.12034/j.issn.1009-606X.215256

Asbtract ( )   PDF (293KB) ( )  

Related Articles | Metrics

The magnetizing roasting and magnetic separation without addition of reductant were used to treat all-size siderite iron ore from China for recovery of iron concentrate. The results showed that the final iron concentrate containing 63.15% total Fe content with the iron recovery rate of 92.52% was obtained under the conditions of roasting of siderite ore at 800℃ for 15 min without addition of reductant, and separation of roasted ore by grinding up to the particle sizes of below 0.074 mm with 90% at 0.10 T magnetic field intensity. The elements of Mn, Mg and part of Ca existed in the form of isomorphism with Fe in the iron concentrate.

Micro-scale Coupling Process of Pervaporation and Esterification Reaction

CHEN Yang HU Jia-yu HU Jia-qian LIU Jun-teng ZHANG Wei-dong

Chin. J. Process Eng.. 2016, 16(2):  238-244.  DOI: 10.12034/j.issn.1009-606X.215343

Asbtract ( )   PDF (601KB) ( )  

Related Articles | Metrics

A new type of membrane microreactor was designed and set up. The intensification of miniaturization for the coupling process of pervaporation and reaction was investigated. The esterification reaction was chosen as a model reaction. The influences of the content of catalyst and temperature on the reaction were examined in the membrane microreactor with and without pervaporation. The results showed that conversion rate rose from 13.6% to 54% with pervaporation under the conditions of 65℃ and residence time of 60 min. The large specific surface area and short diffusion distance of the membrane microreactor could promote the removal of water and intensify the coupling process of pervaporation and reaction. The conversion rate of esterification was 54.0% in the membrane microreactor and 29.3% in the conventional macro-scale membrane reactor under the conditions of 65℃, residence time 60 min and content of Zr(SO4)2 15%(w). In addition, the deactivation of catalyst could be effectively reduced in the membrane microreactor. Its repeatable utilization was improved.

Process Intensification of Chromite Ore Decomposition by Sulfuric Acid

WANG Zheng-chen ZHANG Yang NIE Yao ZHENG Shi-li QIAO Shan CHEN Xiao-fang FAN Bing-qiang

Chin. J. Process Eng.. 2016, 16(2):  245-251.  DOI: 10.12034/j.issn.1009-606X.215396

Asbtract ( )   PDF (568KB) ( )  

Related Articles | Metrics

In order to overcome the harsh decomposition of chromite ore by sulfuric acid, both mechanical activation and oxidant were used as a new method to intensify the decomposition process by sulfuric acid. The effects of ratio of liquid to solid, concentration of H2SO4, mechanical activation, oxidant addition and leaching temperature on the leaching rate of Cr from chromite ore originated in South Africa were examined, and the leaching kinetics of Cr was analyzed. The results showed that the optimum leaching conditions were the ratio of sulfuric acid to solid 2.4 mL/g, H2SO4 concentration 80%(w), mechanical activation time 20 min, oxidant addition 13%(w), leaching temperature 120℃ and leaching time 5 h. Under the optimum conditions, the leaching rate of Cr reached 92.36%. The leaching process of Cr was in line with the unreacted shrinking core model.

Analysis on Coking Quality of Coal for COREX and Prediction Model

XU Da-an WU Keng WANG Ning ZHU LI MEN Zheng-chao ZHANG Li CHAO Chang-yao

Chin. J. Process Eng.. 2016, 16(2):  252-258.  DOI: 10.12034/j.issn.1009-606X.216023

Asbtract ( )   PDF (421KB) ( )  

Related Articles | Metrics

The two coals used in COREX-C3000 process were studied. Pulverization, cold strength, hot performance, optical textures and microstructure of coal chars A and B produced by roasting were measured and analyzed. The results showed that the pulverization rate of coal char A declined from 32% to 11% while that of B rose from 12% to 22% with the increase of roasting time. The cold strength of coal chars A and B changed suddenly in about 6 h, indicating that the coking process was finished in 6 h. The mosaic texture content of coal char A was higher than that of B with over 4%, so its function as skeleton in COREX instead of coke would be better than coal char B. The fusain content of coal char B was much higher than that of A with over 25%, which high lighted its function as heat source and reductant. The relationship between optical texture and hot performance of coal char could be obtained by multiple linear regression for establishment of a reliable prediction model of coal char quality.

Numerical Simulation on Sintering of Low-carbon Iron Ore

LIU Ting-sen ZHANG Xiao-hui QING Shan ZHANG Guo-xiong

Chin. J. Process Eng.. 2016, 16(2):  259-265.  DOI: 10.12034/j.issn.1009-606X.215367

Asbtract ( )   PDF (403KB) ( )  

Related Articles | Metrics

The heat transfer calculation model on the sintering process of iron ore with partially substituted biomass was established, the temperature fields of sintering under 7 sintering schemes were simulated with Fluent software, which were conventional sintering, and substituting conventional fuels by 10%, 20% and 30% bamboo char and chestnut shell char. Based on the calculated results, the reliability of this model was verified by the experimental data obtained by conducting 10% substituting scheme in the factory. And the model was evaluated from the perspectives of the highest temperature and cooling rate of material layer. The results indicated that the solid depth of 20% substituting schemes of bamboo char and chestnut shell char under the solid highest temperature of over 1573 K was 0.47 and 0.49 m, respectively. The solid depth under 20% substituting schemes was more than that of the conventional scheme, 10% and 30% substituting scheme, leading to the increase of the blocking amount of consolidation. The solid depth under 30% substituting schemes of bamboo char and chestnut shell char at the cooling rate of below 120 K/min was 0.458 and 0.480 m, respectively, which was more than that of the conventional scheme, and 10% and 20% substituting scheme, and the mechanical strength of sintering ore could be effectively improved. The bio-chars with much higher ignition point were beneficial to maintaining the highest temperature of material layer, while bio-chars with much lower ignition point were beneficial to improving sintering speed.

Recovery of Copper from Cupronickel Alloy Waste by Low Current Density Electrolysis

WANG Fei LI Hong-juan LI Lei XIE Xiao-feng QIU Shi-wei WEI Jun-qiang

Chin. J. Process Eng.. 2016, 16(2):  266-271.  DOI: 10.12034/j.issn.1009-606X.215359

Asbtract ( )   PDF (505KB) ( )  

Related Articles | Metrics

Recovery of copper from cupronickel alloy scraps was carried out with direct low current density electrolysis method. The effects of electrolyte temperature, current density and gelatin concentration on the cathode copper quality were examined. The results show that the diffusion rate of copper ion can be accelerated while the electrolyte temperature rises in a certain range, which will ease the lacking degree of copper ion on the surface of cathode and fine the crystallization of cathode copper, though the cathode over-potential deceases. When the Cu2+ and H2SO4 concentrations are of 45 g/L and 180 g/L, the current density of 100 A/m2 is less than 0.1 times of limiting current density in 48 h, the electrolysis process is in Tafel area, smooth cathode copper product can be obtained. Under the conditions of electrolyte temperature 60℃, cathode current density 100 A/m2 and gelatin concentration 40 mg/L, the purity of copper cathode of 99.98% can be obtained, while the residual anode rate is 17%~19% and copper recovery rate 98.6%.

Preparation of Trypsin Molecularly Surface-imprinted Material and Its Macromolecular Recognition Characteristics

CHEN Tao SHI Nan MEN Ji-ying GAO Bao-jiao

Chin. J. Process Eng.. 2016, 16(2):  272-278.  DOI: 10.12034/j.issn.1009-606X.215345

Asbtract ( )   PDF (645KB) ( )  

Related Articles | Metrics

Trypsin (TRY) molecularly surface-imprinted material was prepared by synchronous grafting polymerization and surface imprinting with crosslinked polyvinyl alcohol (CPVA) microspheres as matrix. The reaction between methyl acryloyl chloride and the hydroxyl groups on the surface of CPVA microspheres occurred quickly, resulting in the modified MAO-CPVA microspheres with a great deal of polymerizable double-bond methylacryloyl (MAO) group. Anionic monomer sodium p-styrene sulfonate (SSS) and template TRY in a certain molar ratio were added in an aqueous solution, interacting each other. And the crosslinker N, N'-methylene bisacrylamide (MBA) was further added, and the modified MAO-CPVA microspheres were dispersed in the aqueous medium, the free radicals were produced by ammonium persulfate and sodium bisulfite redox initiating system, the graft-crosslinking polymerization of SSS surrounded around the template TRY and crosslinker MBA was conducted so that TRY surface-imprinted material MIP-PSSS/CPVA microspheres were obtained, and characterized. Moreover, their macromolecular recognition characteristics were studied. The results show that the MIP-PSSS/CPVA microspheres possess excellent binding affinity and specific recognition selectivity for the template TRY. The adsorption capacity of TRY on the microspheres reaches up to 85.9 mg/g, and the selectivity coefficient of imprinted TRY in contrast to protein lysozyme is up to 17.52.

Interaction between Complexes of Chitosan with La3+　and Dy3+　and Bovine Serum Albumin

WU Jin-xiu LIU Zhao-gang HU Yan-hong WANG Mi-tang

Chin. J. Process Eng.. 2016, 16(2):  279-285.  DOI: 10.12034/j.issn.1009-606X.216024

Asbtract ( )   PDF (276KB) ( )  

Related Articles | Metrics

The interaction between chitosan (CS), its complexes CS-La and CS-Dy, and bovine serum albumin (BSA) in vitro under simulative physiological conditions was studied by fluorescence, ultraviolet-visible absorption and synchronous fluorescence spectrometry. The results showed that CS, CS-La, CS-Dy had strong effects on quenching of the fluorescence launching and enhanced the UV absorption spectra of BSA. After the fluorescence quenching, the obtained data were analyzed by Stern-Volmer equation, the results indicated that the reactions between BSA and CS, CS-La and CS-Dy generated new complexes. The quenching belonged to static fluorescence quenching, with non-radiation energy transfer happening within single molecule, but the static and dynamic quenching coexisted in the reactions between CS and CS-Dy and BSA. The binding constant KA (291 K, CS-BSA: 1.807′104 [L/(g·s)], CS-La-BSA: 3.065′104 [L/(g·s)], CS-Dy-BSA: 2.193′104 [L/(g·s)]; 310 K, CS-BSA: 2.665′104 [L/(g·s)], CS-La-BSA: 2.022′104 [L/(g·s)], CS-Dy-BSA: 7.246′104 [L/(g·s)] and thermodynamics parameters (DH, DS, DG) were calculated, respectively according to the equation of fluorescence spectrometry at different temperatures. Based on thermodynamic data, the main reactions between CS and CS-Dy and BSA were electrostatic and hydrophobic forces, but those between CS-La and BSA van der Waals and hydrogen bond forces. The effects of CS, CS-La and CS-Dy on the conformation of BSA shown by synchronous fluorescence spectrometry indicated that they changed the micro-environment and conformation of BSA molecules.

High Cell Density Fermentation of L-Glutamate Oxidase and Its Catalysis for Synthesis of a-Ketoglutaric Acid

FAN Xiang-chen CHEN Rui-dong LIU Jia XU Ji-si LI Zhen

Chin. J. Process Eng.. 2016, 16(2):  282-297.  DOI: 10.12034/j.issn.1009-606X.215338

Asbtract ( )   PDF (278KB) ( )  

Related Articles | Metrics

Lactose was used to replace isopropyl β-D-1-thiogalactopyranoside (IPTG) as inducer, the feeding strategy was optimized to improve cell density, induction strategy was studied for improvement of L-glutamate oxidase (LGOX) activity, the whole-cell conversion biocatalyst from high cell density fermentation was used to produce a-ketoglutaric acid (a-KG) from L-glutamic acid. The results showed that LGOX activity was up to 4.78 U/mL from 3.12 U/mL by IPTG induction in the shake flask. In a 5 L fermenter, cell density was increased from 2.49 to 41.6 g/L, and LGOX activity reached 59 U/mL with two-stage feeding strategy combining the exponential feeding with DO-stat feeding strategy. By optimizing the induction strategies, the maximal cell density and LGOX activity reached 48.4 g/L and 156.1 U/mL, improvement of 19.4- and 50-fold before optimization, respectively. a-KG yield was up to 5160 g/L by whole-cell conversion, increased by 48-fold.

Continuous Preparation of (R)-Phenyl-ethanediol by Catalysis of Nanoparticles Immobilized Bi-enzyme Coupling System

PENG Yi-qiang ZHANG Yao

Chin. J. Process Eng.. 2016, 16(2):  286-291.  DOI: 10.12034/j.issn.1009-606X.215361

Asbtract ( )   PDF (298KB) ( )  

Related Articles | Metrics

SiO2 nanoparticles prepared by the alkoxide hydrolysis precipitation method were covalently immobilized with carbonyl reductase (CR) and formate dehydrogenase (FDH). The nanopartiles immobilized CR and FDH were coupled and used for continuous catalytic conversion of β-hydroxyacetophenone to optical purity (R)-phenyl-ethanediol, and in situ NADH regeneration and recycling analyzed. The results showed that the enzyme loading of nanopartiles immobilized CR and FDH was 3.32 and 5.55 mg/g, their catalytic capability 50%~60% of native enzyme, their optimal reaction pH value 6.5 and 8.5, and their optimal reaction temperature 40 and 45℃, respectively. The production of (R)-phenyl-ethanediol was accumulated as 35.6 g/L, and the productivity of unit nanoparticles 178 g/g, while the coupling system was carried out for 12 batches. The nanopartiles immobilized CR and FDH could be reused after collection with centrifugal separation.

Separation of Propionibacterium freudenreichii Cells with Membranes and ex-situ Transformation of Vitamin B12

XU Guo-xia DU Wei WANG Zi-qiang WANG Yun-shan; ZHANG Li-ping SU Zhi-guo

Chin. J. Process Eng.. 2016, 16(2):  298-302.  DOI: 10.12034/j.issn.1009-606X.215431

Asbtract ( )   PDF (304KB) ( )  

Related Articles | Metrics

The application of membrane separation of Propionibacterium freudenreichii cells was studied. The effects of membrane material and pore size on the flux and cellular activity were examined. The Vitamin B12 ex-situ transformation was also investigated. The results showed that spiral wound membrane was more suitable for on-line cell separation compared with ceramic membrane. When the fermentation broth was treated with 0.22 mm spiral wound membrane, the biological activity of cells was almost not damaged, with a survival rate of 99.5%, Abo-cbi conversion rate of 78.8% was obtained at 30℃ for 72 h with 4 times concentrated fermentation broth and the productivity of Vitamin B12 reached 53.9 mg/L.

Effects of Tundish Gunning Materials on Steel Cleanliness

LIU Yu LI Guang-qiang YANG Zhi-zheng RAO Jiang-ping

Chin. J. Process Eng.. 2016, 16(2):  303-309.  DOI: 10.12034/j.issn.1009-606X.216025

Asbtract ( )   PDF (631KB) ( )  

Related Articles | Metrics

The reaction of three kinds of MgO, Al2O3 and MgO+CaO based tundish gunning materials (GM) with molten steel were studied, their effects on the contents of total oxygen, total nitrogen, Al, Ti and Si in steel, and composition, quantity and size distribution of inclusions examined, and the infiltration and erosion of gunning materials at the interface with steel analyzed. The results show that compared with MgO and Al2O3 based GM, the use of MgO+CaO based GM could control the total oxygen content and inclusions in steel better at 1550℃, leading to the improved steel cleanliness with the final oxygen content of 8.5′10-5, and the reoxidation of steel was reduced and the formation of fine inclusions was improved, leading to <1 mm inclusions with 98.13% proportion. Al and Ti were firstly oxidized, and then Si and Mn. The erosion of Al2O3 based GM was mainly caused by wearing, and that of MgO based GM by molten steel infiltration. The use of MgO+CaO GM could reduce the secondary pollution of molten steel, which was more conducive to the production of clean steel.

Preparation of Iron Oxide Yellow with Iron Sulfate Heptahydrate By-product from Production of Titanium Dioxide

WU Peng-hui JIA Ding-tian XU Wen-jie LI Yi-chun LI Ming-yu

Chin. J. Process Eng.. 2016, 16(2):  310-316.  DOI: 10.12034/j.issn.1009-606X.215400

Asbtract ( )   PDF (347KB) ( )  

Related Articles | Metrics

With ferrous sulfate by-product from the production of titanium dioxide as main raw material, iron oxide yellow was prepared. Not only the effects of mass ratio of NaOH to FeSO4×7H2O, initial Fe2+ concentration, aeration rate and temperature on the seed crystal, but also those of concentration of seed crystal, pH value and initial ferrous sulfate amount on the iron oxide yellow examined. The process conditions were optimized. The results showed that the production was 4.00 g, the productivity was 12.01 g/h, the seed crystal was claybank and colloid when the molar ratio of NaOH to FeSO4×7H2O was 0.5, initial Fe2+ concentration 0.7 mol/L, aeration rate 2.5 L/min and temperature 35℃ in the preparation stage of seed crystal. Meanwhile, the production was 20.97 g, the productivity was 8.99 g/h, the iron content in oxide was 86.95% when the concentration of seed crystal was 20%, pH value 4.5~ 5.0, initial ferrous sulfate amount 60 g in the preparation stage of iron oxide yellow. The prepared iron oxide yellow was homogeneous claviform particles with the phase composition of FeOOH, average diameter 860 nm, and specific surface area 21.98 m2/g, and its quality was over the first grade of industrial standard HG/T 2249-91.

Recovery of Ferrous Oxalate from Iron Removal Process of Ferrochrome Acid Leaching Solution and Preparation of Iron Oxide Black Pigment

YANG Liu ZHANG Yang QIAO Shan ZHENG Shi-li ZOU Xing

Chin. J. Process Eng.. 2016, 16(2):  317-322.  DOI: 10.12034/j.issn.1009-606X.215365

Asbtract ( )   PDF (434KB) ( )  

Related Articles | Metrics

The ferrous oxalate from iron removal process of ferrochrome acid leaching solution was treated by oxygen oxidation and ammonia leaching for recovery of oxalate and preparation of iron oxide black pigment. The effects of ammonia amount, reaction temperature, ratio of liquid to solid, reaction time, oxygen flow rate, solution pH value and crystallization temperature on the leaching rate of C2O42- and the performance of iron oxide black were studied. The optimal conditions were obtained as follows: crystallization temperature 60℃, reaction temperature 80℃, 3 times theoretical amount of ammonia, ratio of liquid to solid 5 mL/g, oxygen flow rate 0.1 L/min, pH value 6.9~7.4, and reaction time 3 h. Under the optimal conditions, the leaching rate of C2O42- was almost 100%, and the iron oxide black had excellent pigment performance compared with 722 iron oxide black product.

SDBS-assisted Synthesis of Y2O3/Ag3VO4 Photocatalyst and Its Photocatalytic Activity for Degradation of Rhodamine B under Visible Light Irradiation

QIN Li-qin PANG Qi TAO Ping-fang CHEN Yuan TANG Lian-dong

Chin. J. Process Eng.. 2016, 16(2):  323-329.  DOI: 10.12034/j.issn.1009-606X.215355

Asbtract ( )   PDF (564KB) ( )  

Related Articles | Metrics

Ag3VO4 and Y2O3/Ag3VO4 photocatalysts were synthesized by precipitation and impregnation with the assistant of sodium dodecylbenzene sulfonate (SDBS), and V2O5, AgNO3 and Y(NO3)3×6H2O as raw materials, their structure and morphology characterized, and the synthesis mechanism was analyzed. The results showed that the absorption edge of Y2O3/Ag3VO4 was red-shifting, and the energy gap was 1.83 eV with SDBS assistance. The synthesized Y2O3/Ag3VO4 showed excellent photocatalytic activity and stability for degradation of rhodamine B (RhB) because of the adsorption enrichment of benzene and effective separation of photogenerated electron-hole pair. The degradation rate of 8 mg/L RhB in 200 mL solution was 94.2% by 0.08 g 3%Y2O3/Ag3VO4 in 15 min illumination.

Preparation and Characterization of High Performance Biomass Char Reductant

YANG Xing-wei MA Wen-hui WEI Kui-xian CHEN Zheng-jie YANG Xi DONG Yan-qi

Chin. J. Process Eng.. 2016, 16(2):  330-335.  DOI: 10.12034/j.issn.1009-606X.215356

Asbtract ( )   PDF (711KB) ( )  

Related Articles | Metrics

Bio-char reductant was prepared with walnut shells, and characterized to analyze the relationship between chemical components, functional group distribution and resistivity. The results showed that resistivity of bio-char declined from 6288.7 to 1515.9 mW×m with increasing of pyrolysis temperature from 400℃ to 1450℃. Fixed carbon content increased and volatile matter content declined with increasing of pyrolysis temperature. Carbonyl and aliphatic functional groups in the char were gradually decomposed, the interlamellar spacing of d002 on the lattice plane decreased gradually, its crystallinity, aromatization and carbon structure ordering degree increased with increasing of pyrolysis temperature. In the pyrolysis temperature range of 500~700℃, high-performance bio-char reductant with high yield (≥24%), high resistivity (≥5800 mW×m), high fixed carbon content (≥80%) and low ash content (≤4%) was obtained. The char had developed pores, and could be used as the reductant for industrial silicon production.

Preparation of Bi2GeO5 Nanorods and Their Photocatalytic Properties

ZHENG Wen-hui ZHANG Li-xin TONG Zi-qiang ZHANG Qian NI Chang-hui

Chin. J. Process Eng.. 2016, 16(2):  336-340.  DOI: 10.12034/j.issn.1009-606X.215390

Asbtract ( )   PDF (402KB) ( )  

Related Articles | Metrics

Pure Bi2GeO5 nanorods were prepared in a liquid phase reaction followed by calcination of the precursor with a mixture of glycerol and ethanol as solvent and Bi(NO3)×5H2O and GeO2 as raw materials, and their phase and microstructure characterized. The prepared Bi2GeO5 nanorods were used in photocatalytic degradation of Rhodamine B (RhB). The result showed that the prepared Bi2GeO5 had a uniform rod shape and good stable photocatalytic activity. With the increase of concentration of Bi2GeO5 nanorods, their degradation effect firstly increased markedly, and then decreased. Their highest photodegradation rate reached 90.4% when their concentration was 1.5 g/L and the illumination time 150 min. Meanwhile, the formation mechanism of Bi2GeO5 nanorods was also analyzed as followed: in the hydrothermal process, first of all, the complexes with bismuth ions and ethylene glycol were self-assembly transformed into nanorod structure, and then the ion exchange reaction happened between the free germanium acid radical ions in the solution and the complexes with nanorod structure, and the Bi2GeO5 nanorods formed.

Synthesis and Electrochemical Performance of 3D Redox Graphene Oxide-Ag/Nickel

CHANG Jian-xia JIU Hong-fang JIAO Hong-qian ZHANG Shao-mei WU Shi-mei SONG Shuang

Chin. J. Process Eng.. 2016, 16(2):  341-345.  DOI: 10.12034/j.issn.1009-606X.215386

Asbtract ( )   PDF (387KB) ( )  

Related Articles | Metrics

Graphite oxide (GO) was prepared by a modified Hummer method, and three-dimensional redox graphene oxide-Ag/nickel foam (rGO-Ag/NF) composite prepared by dry immersion method. Its crystalline phase, morphology and composition were characterized, and electrochemical properties analyzed, such as galvanostatic charge-discharge and cyclic voltammogram. The results showed that rGO-Ag/NF composite had a porous structure in which the diameter of Ag particles was 200 nm. At the current density of 5 mA/cm2, its specific capacitance was estimated as 1.59 F/cm2. The composite also had a retention rate of 70% of its initial capacitance after 1000 cycles, indicating excellent recycling stability.

Preparation and Electrochemical Performance of Graphene Prepared by Liquid-phase Exfoliation

ZHENG Lu JIN Ri-ya SUN You-yi MA Jun

Chin. J. Process Eng.. 2016, 16(2):  346-350.  DOI: 10.12034/j.issn.1009-606X.215383

Asbtract ( )   PDF (446KB) ( )  

Related Articles | Metrics

Single- and multi-layer graphene was fabricated from expanded graphite by liquid-phase exfoliation method in organic solvents. Its morphology and structure were characterized. The effects of organic solvent, time and reductant on the electrical properties of graphene platelets were studied by four-point probe characterization method, and the preparation conditions of graphene optimized. The results show that graphene platelets have high electrical conductivity by using acetone as the dispersant, which can achieve 219.09 S/cm. The graphene exhibits good electrochemical performance compared with the expanded graphite, its specific capacitance reaches 18.8 F/g. In PBS buffer solution of pH=7, a sensitive stripping peak at 0.1 V to Pb2+ ion occurs, and the detection limit is 0.05 mmol/L.

Preparation of Fe3O4 Nanoparticles with Impinging Stream-rotating Packed Bed and Their Adsorption Property to Heavy Metal Ions

FAN Hong-lei JIAO Wei-zhou QI Gui-sheng LIU You-zhi

Chin. J. Process Eng.. 2016, 16(2):  351-355.  DOI: 10.12034/j.issn.1009-606X.215382

Asbtract ( )   PDF (633KB) ( )  

Related Articles | Metrics

A novel impinging stream-rotating packed bed was used to prepare Fe3O4 nanoparticles with aqueous solutions of FeCl3/FeCl2 and NaOH as raw materials. The effects of high gravity factor, liquid flow rate and reactant concentrations on the particle size of Fe3O4 were examined. Moreover, the adsorption property of Fe3O4 nanoparticles to Pb(II) and Cd(II) was evaluated. The results showed that higher high gravity factor, larger liquid flow rate and higher concentration of reactants were associated with smaller size of Fe3O4 nanoparticles. Fe3O4 nanoparticles were quasi-spherical with the average diameter of about 10 nm and showed superparamagnetic behavior with the saturation magnetization of 60.5 emu/g under the optimal operation conditions, which were high gravity factor of 65.32, liquid flow rate of 60 L/h and FeCl3×6H2O concentration of 0.321 mol/L. The adsorption of Fe3O4 nanoparticles to Pb(II) and Cd(II) well fitted to the Langmuir isothermal model, and their maximum adsorption capacities calculated were 30.47 and 13.04 mg/g for at pH value 6.0, respectively.

Preparation and Performance of Cellulose Acetate Membrane with Mixed Solvents

LIU Fang LI Qiao-ling

Chin. J. Process Eng.. 2016, 16(2):  356-360.  DOI: 10.12034/j.issn.1009-606X.215327

Asbtract ( )   PDF (595KB) ( )  

Related Articles | Metrics

Cellulose acetate (CA) membrane was prepared by liquid-solid phase inversion method with cellulose acetate, acetone, N-methylpyrrolidone (NMP) and polyethylene glycol 400 (PEG-400) as raw materials. The structure and morphology of CA membrane were characterized. At room temperature, the prepared CA membrane was used to treat deionized water and 500 mg/L polyethylene glycol 600 under the pressure of 0.1 MPa in its water flux and rejection rate, respectively. The effects of mixed solvent content, reaction temperature and PEG-400 content on the separation properties of membrane were examined. The results showed that under the conditions of NMP and PEG-400 contents of 60% and 6%(w), and reaction temperature of 60℃, the prepared CA membrane surface was smooth and the pore size distribution uniform, its water flux was 212.87 L/(m2×h), and the rejection rate 87.67%.