Volumn Content

The Chinese Journal of Process Engineering 2003 Vol.3 Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Solid Circulating Rate in a Spouted–fluidized Bed with Draft Tube at Elevated Pressure LIU Xiang-dong; ZHANG Ming-yao    2003, 3 (1): 0-0.   Abstract （1704）      PDF （268KB）（903）       Knowledge map    Save The momentum equation with gravity considered was applied to describe the variable-mass flow in the vertical perforated channel for radial packed reactors. The profiles of pressure and the virtual pressure along the perforated channels were measured for upward and downward flows in the distributor or collector on large scale mock-up. Under the experimental conditions, the coefficients of momentum exchange for distribution and collection were calculated to be equal to 0.77 with the average relative error of 10% and 1.26 with the average relative error of 15% respectively. It is concluded that gravity can not be neglected as the mass velocity is relatively small. Related Articles | Metrics Select Influence of KCl Concentration on Chitin Deacetylation in Microwave Field YANG Zhen-qiu; SONG Bao-zhen; OUYANG Fan    2003, 3 (1): 0-0.   Abstract （1441）      PDF （139KB）（654）       Knowledge map    Save This paper presents the effect of KCl concentration on chitin deacetylation in the microwave field. The experimental result shows that the reaction was enhanced when salts were introduced into the reaction system. The degree of deacetylation (DD) of chitosan increases with time, but the rate of increase slows down gradually, revealing the characteristics of first order reaction. The molecular weight (MW) of chitosan decreases with time. The DD of chitosan decreases with the increase of the concentration of KCl, but it is higher than that of the control in the concentration range of KCl investigated. When KCl concentration equals 0.05 mol/L, the DD is 79.3%, as compared with that of the control (69.6%). Along with the increase of KCl concentration, the MW of chitosan decreased, but it increased when the concentration was greater than 0.2 mol/L. Related Articles | Metrics Select Harvesting Spirulina Cells by Foam Flotation Technique on a Laboratory Scale ZENG Wen-lu; LI Hao-ran; LI Bao-hua; CONG Wei; CAI Zhao-ling; OUYANG Fan    2003, 3 (1): 0-0.   Abstract （1573）      PDF （172KB）（630）       Knowledge map    Save Taking Spirulina cells as the model, experiments were carried out on a novel and effective slant-armed bubble column to investigate the feasibility of foam flotation of micro-algal cells. The effects of a number of operation parameters such as carrying-gas flow rate, solution pH value, concentrations of ethanol and Tween 20 on the enrichment ratio and recovery of cells were examined and some useful data were presented. Related Articles | Metrics Select Characteristics and Active Energy for the Precursor of Lithium Manganese Oxides ZHAO Ming-shu; SONG Xiao-ping; ZHAI Yu-chun; TIAN Yan-wen    2003, 3 (1): 0-0.   Abstract （2561）      PDF （280KB）（745）       Knowledge map    Save The decomposition kinetics of lithium manganese oxides precursor in air atmosphere was investigated at different heating rates with differential temperature analyses. The apparent activation energy of each stage was calculated using the Doyle-Ozawa and Kissinger methods. X-ray diffraction, granularity analysis, scanning electron microscopy and transmission electron microscopy showed that the LiMn2O4 phase was pure, with regular appearance and a uniform granularity distribution. Related Articles | Metrics Select Cathodic Reduction of Zn Complex Ion in the ZnCl2–NH4Cl Electrolyte MA Chun; YU Zhong-xing    2003, 3 (1): 0-0.   Abstract （1626）      PDF （160KB）（803）       Knowledge map    Save The effect of culture conditions on microbial flocculant production from Nocardia sp. CCTCC M201005, a newly isolated bioflocculant producing bacterium, was investigated. Sucrose was proved to be an optimum carbon source. Complexity of organic and inorganic nitrogen sources stimulated both bacterial growth and flocculant synthesis, among which corn steep complexed with urea was the most efficient. Proper corn steep concentration accelerated bacterial growth while relatively low corn steep concentration was more favorable for bioflocculant formation. The highest flocculation activity was obtained at C/N 20~30. The medium supplemented fermentation was designed and carried out. The results showed that the final flocculation activity and cell density were increased more than 10% and 35% respectively compared with those in the fermentation with no medium supplementation. Flocculation conditions of bioflocculant produced by Nocardia sp. CCTCC M201005 (named REA-11) were also discussed. The thermostability of REA-11 was high at pH 3.0 to 6.5 and its activity was markedly improved by the addition of CaCl2. As a co-flocculant, the optimum concentration of CaCl2 was 8 mmol/L in this flocculation system. Related Articles | Metrics Select Preparation of Surface-modified Nanosized Al(OH)3 Powders LIU You-zhi; LI Yu; LIU Lai-shuan    2003, 3 (1): 0-0.   Abstract （1636）      PDF （363KB）（712）       Knowledge map    Save Nanosized Al(OH)3 powder was prepared by the carbonation method from sodium aluminates solution and carbon dioxide. The influence of concentration of reactant, rotating speed of rotating packed bed and ratio of gas-liquid flow rate on Al(OH)3 particle size in the preparation process was investigated. The optimal operating optimum conditions were determined as follows: sodium aluminates 120 g/L, ratio of gas-liquid flow rate 1.5~4.0, rotating speed 1200 r/min. Adding surface modifier TEBAC/PO43- is helpful to the control of agglomeration of Al(OH)3 particles. The product was characterized by TEM and XRD. The prepared particles are monoclinic and well-dispersed with a mean size of 20 nm . Related Articles | Metrics Select Photoelectrochemical Degradation of PCP on TiO2 Film Electrode XU Wen-lin;WANG Ya-qiong    2003, 3 (1): 0-0.   Abstract （1597）      PDF （58KB）（615）       Knowledge map    Save An investigation of photoelectrochemical degradation of pentachlorophenol (PCP) on a TiO2 film electrode was presented. The TiO2 film electrode was prepared by anodisation of titanium metal in sulfuric acid solution and its photoelectrocatalystic performance was studied. The destruction of PCP follows approximately the first-order kinetics. The reaction constant decreases slightly from 2.6×10–5 s–1 to 2.0×10–5 s–1 as the initial PCP concentration is increased from 0.1 mmol/L to 1.0 mmol/L under the experimental condition. Related Articles | Metrics Select Physical Modeling of the Vortex Phenomenon in Continuous Casting Mould LEI Hong; ZHU Miao-yong; HE Ji-cheng    2003, 3 (1): 0-0.   Abstract （1439）      PDF （238KB）（611）       Knowledge map    Save Two different types of 1-[2-(hydroxyethoxy)methyl]-6-naphthylmethylthymines have been designed, synthesized and evaluated for their anti-HIV-1 activities in different cells lines. The binding free energy (DG) including steric and electrostatic between the two different ligands and reverse transcriptase Non-Nucleoside Binding Pocket (NNBP) have been docked and calculated to evaluate their accommodation circumstance on a SGI work station. The DG and anti-HIV-1 activity has been correlated in order to guide further drug design, which showed that the steric binding effect dominated in the whole binding action between the compounds and reverse transcriptase (RT). The results showed that more negative DG led to higher activity of compounds. Related Articles | Metrics Select Alkylation Reaction of Thiophene with Olefins over Acid Catalyst of AlCl3 Supported Resins LUO Guo-hua; XU Xin; YANG Chun-yu TONG Ze-min; PENG Shao-yi    2003, 3 (1): 0-0.   Abstract （2979）      PDF （176KB）（739）       Knowledge map    Save A gold leaching process for an acid leached residue from an arsenic refractory gold concentrate in lime slurry under pressurized oxygen is investigated. The residue contains 17.4% of elemental sulfur. The experimental results show that the optimum quantity of lime added to the leaching solution should ensure the mole ratio of elemental sulfur to OH– in the range of 0.8 to 1.1. In 3 to 5 h, 90% of gold is leached at 85°C under 0.1 to 0.3 MPa oxygen pressure with the optimum lime addition in the solution. The thiosulphate produced from elemental sulfur in lime solution during oxygen leaching might be the major complexing agency for gold leaching. Related Articles | Metrics Select Separation and Purification of Stigmasterol and b-Sitosterol from Phytosterol by the Crystallization Method XU Wen-lin; HUANG Yi-bo; QIAN Jun-hong; SHA Ou    2003, 3 (1): 0-0.   Abstract （1841）      PDF （224KB）（1058）       Knowledge map    Save Influences of HNO3, H2O2 and BTA concentrations on filming of copper surface and CMP process were studied by electrochemical methods. Cu EIS in various media were examined. Relations of corrosion current density to polishing pressures and rotative rates were investigated. Changes of corrosion potential and polarization curves were explored. Electrochemical mechanisms of CMP were explained by changes of electrochemical variables such as corrosion potential and corrosion current density. The formula of 1% HNO3+1% BTA+0.2% H2O2+5% g-Al2O3 was confirmed to be feasible and reasonable. Related Articles | Metrics Select Research Advances in Biodesulfurization Technology of Coal and Oil JIANG Cheng-ying;WANG Rong; LIU Hui-zhou; CHEN Jia-yong    2003, 3 (1): 0-0.   Abstract （1637）      PDF （205KB）（581）       Knowledge map    Save Thermal plasma pyrolysis of waste tyres for recovering energy was performed in a nitrogen plasma reactor. The main gaseous products were identified by chromatography as H2, CO, CH4, C2H2 and so on. From a series of experiments, the effects of the process parameters of thermal plasma pyrolysis were investigated. Under our experimental conditions with steam injection, the total contents of H2 and CO reached up to 38.3% in the gas product, C2H2 up to 4%, and the maximum calorific value of the pyrolysis gas was 8.96 MJ/m3. The results indicate that plasma-assisted thermal decomposition of waste tyre particles may be a useful way for recovering energy and useful chemicals. Related Articles | Metrics Select Catalytic Cracking of Bio-oil from Biomass Pyrolysis GUO Xiao-ya; YAN Yong-jie; LI Ting-chen; REN Zheng-wei; YUAN Chuan-min    2003, 3 (1): 0-0.   Abstract （1616）      PDF （238KB）（659）       Knowledge map    Save In preparation of motor fuel, bio-oil from pyrolysis of biomass must be further upgraded so as to improve its quality. Upgrading operation via catalytic cracking was carried out in a tubular fixed-bed reactor with HZSM-5 as catalyst, under atmospheric pressure, in the temperature range of 340~420oC, and at weight space velocity (WHSV) of 2.9~5.6 h-1. The effects of process parameters such as temperature, WHSV, solvent and size of catalyst pellets on product yield were studied. The results show that 44.68% (w) of organic distillate was yielded at temperature 380oC and WHSV=3.7 h-1. In addition, the analysis of upgraded oil shows that the amount of oxygenated compounds in the bio-oil, such as organic acid, aldehyde, ester, alcohol, ketone were greatly reduced meanwhile aromatic and polyaromatic hydrocarbons were formed. Related Articles | Metrics Select Preparation of Super-fine Spherical CaCO3 by the Carbonation Method XIANG Lan; XIANG Ying; YUAN Hong-xia; WANG Ting-jie    2003, 3 (1): 0-0.   Abstract （2633）      PDF （101KB）（690）       Knowledge map    Save The effects of temperature, time, and agitation speed on the acidic precipitation of ammonium polyvanadate from the plant of vanadate-leaching solution were investigated on a laboratory scale. The results show that for the vanadate-leaching solution containing 30 g/L of vanadium, keeping pH about 2.2 at the beginning of precipitation reaction, temperature at about 95oC, agitation speed at 300 r/min, and reaction time being 120 min, could result in the following results: precipitation rate is more than 99%, H2O content in red cake is less than 20%, Na content in dried red cake is between 0.70% and 1.08%, and sulphur content in dried red cake is between 0.78% and 1.02%. Related Articles | Metrics Select Experiments on Reducing Potassium Chromate and Potassium Dichromate to Chromic Oxide Hydrate under Hydrothermal Conditions YAO Zhi-mao; LI Zuo-hu; ZHANG Yi    2003, 3 (1): 0-0.   Abstract （1742）      PDF （302KB）（779）       Knowledge map    Save Reduction of potassium chromate and potassium dichromate to chromic oxide hydrate under hydrothermal conditions using sucrose as the reducing agent was investigated. The effects of the stoichiometric mole ratio of sucrose to chromate or dichromate salts (Rm), the isothermal temperature (Tiso) and time (tiso) on the conversion of Cr6+ to Cr3+ were also studied in detail. By using the orthogonal experiment L9(34), the order of the above affecting factors was obtained: tiso Related Articles | Metrics Select Pressure Drop Characteristics of Vertical Dilute-phase Gas Conveying JING Shan; JIANG Pan-liang; HU Qing-yuan; WANG Jin-fu; JIN Yong    2003, 3 (1): 0-0.   Abstract （1545）      PDF （132KB）（646）       Knowledge map    Save The chelate resins of dicarboxylic acid dihydrazides-formaldehyde were synthesized by polycondensation of dicarboxylic acid dihydrazides with formaldehyde. The collecting ability for Zn2+ was investigated by batch tests. The collecting efficiency of these three resins decreased in the order of succinic acid dihydrazides-formaldehyde resin>malonic acid dihydrazides-formaldehyde resin>oxalic acid dihydrazides-formaldehyde resin. The influences of pH value, capturing time and temperature were investigated. It is found that the collecting efficiency is dependent on pH value, and high temperature is unfavorable to collecting Zn2+. The resins reach the highest capacity of Zn2+ capture after 3 h of adsorption. Related Articles | Metrics Select New Technology for Pd Recovery from Selectively Leached Residue of Waste Palladium Catalyst YANG Jian-wen;ZHONG Hai-yun;ZHAO Xuan;ZHONG Hui;LI Jian;DAI Yan-yang;MIAO Jian-li    2003, 3 (1): 0-0.   Abstract （1580）      PDF （145KB）（754）       Knowledge map    Save There is still 10~100 g/t Pd in the selectively leached residue of waste catalyst, and five factors are considered to probably cause the result: reabsorption, diffusion resistance in pores, hydrolysis, partial substitution, inclusion etc. Using weak alkaline leaching agent CN– as an alternative was proposed and testified to be effective. By this technique, Pd content in –150 mesh milled residue was dropped from 51.6 g/t to 1.2 g/t. In a 100 t scale vat leaching test with granular materials, Pd was dropped to 3.0 g/t. The leaching recovery is respectively 97.7% and 94.2%. Pd in leaching solution was directly adsorbed with AC (active carbon) with high absorption rate and good selectivity. Pd loaded AC was burned in oxygen-rich fire, and above 99.95% purity of Pd powder was made by the amino-complexing method. This technology has the features of simple process, less facilities required, high metal recovery and high product purity etc. Related Articles | Metrics Select Asymmetric Conversion of 1-Phenyl-1,2-ethanediol by Candida parapsilosis SYB-1 NIE Yao; XU Yan    2003, 3 (1): 0-0.   Abstract （2605）      PDF （148KB）（617）       Knowledge map    Save Thermal cycle resistance of Al2O3/Ni-Ti/Kovar joints was studied, which were prepared by active brazing technique. The experimental results show that the joint shear strength increases after 200~600~200oC thermal cycles. The phenomenon is analyzed in view of the materials thermal expansion, solder microstructure and cycle temperature. The reason of strength increase is that the annealing effect in thermal cycles reduces the joining residual stress. Related Articles | Metrics Select Prediction of Solids Holdup Time Series of a Gas–Solid Circulating Fluidized Bed LI Xiao-xiang; SHI Yan-fu; HUANG Wei-xing; YU Hua-rui; ZHU Jing-xu    2003, 3 (1): 0-0.   Abstract （2323）      PDF （259KB）（625）       Knowledge map    Save A prediction model based on combination of phase space reconstruction with artificial neural network was proposed. In this model, the Takens phase space reconstruction method is used to reconstruct the attractors, which represent the system hydrodynamics from the single variable time series, and the radial based function artificial neural network is used to fit the attractors in phase spaces. Firstly, the model was verified by the Lorenz chaotic system. Then the model was used to predict the local solids holdup fluctuation in a circulating fluidized bed riser with 16 m height and 0.10 m ID. The experiments were conducted with FCC particles and superficial gas velocity ranging from 3.5~8.2 m/s and the solids circulating fluxes ranging from 50~202 kg/(m2.s). The local solids holdup time series signals were measured at 900 Hz using an optical fiber probe. The results showed that (1) the proposed model based on phase space reconstruction and the artificial neural network is a useful method in predicting local solids holdup fluctuation in gas-solid circulating fluidized beds; (2) the predictability of solids holdup in the CFB is possible only in a short-time, in accordance with that the circulating fluidized bed is a chaotic system. Related Articles | Metrics Select Effects of Broth Components on Separation of L-glutamine by Nanofiltration LI Chun; LIU Yuan-shuai; LI Shu-liang; WANG Xiao-lin; CAO Zhu-an    2003, 3 (2): 0-0.   Abstract （1580）      PDF （129KB）（666）       Knowledge map    Save The effects of salt ions and other components in L-glutamine fermentation broth on the separation of L-glutamine and L-glutamic acid by nanofiltration were investigated and the effects of process operation parameters on permeation properties were studied systematically. The optimum dilution times of fermentation broth and temperature was established. The study also showed that bivalent cations could affect the permeation properties of L-glutamine and L-glutamic acid, and decreased observed rejection of glutamic acid by 8%. Higher concentration of (NH4)2SO4 in broth reduced the observed rejection of L-glutamine and L-glutamic acid and permeation flux greatly, but higher concentration of NH4Cl did not, which demonstrated different repulsion forces of membrane to different ions. When the broth was diluted to 1% for L-glutamine concentration and adjusted to pH=7, other salt ions and residual glucose in broth would not significantly influence L-glutamine separation by nanofiltration due to their low concentrations. Related Articles | Metrics Select Studies of Heterogeneous Hydrothermal Stripping from Iron-loaded Naphthenic Acid–Alcohol–Kerosen WANG Xing-yao (王兴尧);KANG Xiao-hong (康晓红);et al.    2003, 3 (2): 0-0.   Abstract （1585）      PDF （303KB）（583）       Knowledge map    Save The technique of hydrothermal stripping from mixed aqueous-organic systems is a promising method for synthesizing oxide ceramic powders for high-performance applications. Some factors influencing heterogeneous hydrothermal stripping with water from iron-loaded organic phase of naphthenic acid–isooctyl alcohol–kerosene, such as initial concentrations of iron and naphthenic acid, concentration of Fe2O3 “seed”, temperature and time, were investigated. Based on the experimental results, the rate equation was established. Nano-ferric oxide powders were obtained by the technique of hydrothermal stripping from the iron-loaded organic phase. The results suggest that the heterogeneous hydrothermal stripping proceeds in 3 steps: adsorption of naphthenic acid dimers and naphthenic complex of iron onto the surface of “seed”, hydrolysis of adsorbed complex of iron, and condensation of hydrolyzed complex. The process activation energy is 115 kJ/mol and the heterogeneous hydrothermal stripping is controlled by a chemical reaction (the hydrolysis of naphthenic complex of iron). Related Articles | Metrics Select Effect of Shear Stress on Suspension Cultures of Taxus chinensis var. mairei HAN Rong-bin; SHI Zhong-dong; YANG Wen-li; YUAN Ying-jin    2003, 3 (2): 0-0.   Abstract （1735）      PDF （157KB）（692）       Knowledge map    Save Based on the systematical study of continuous resolution of DL-alanine employing the immobilized Aspergillus oryzae cell, the kinetics of the enzymic reaction was determined. Furthermore, the method of Newton-Raphson was applied to the solution of one-dimension-steady-diffusion model of packed bed for continuous resolution of DL-alanine. The calculated results of the model, with the error less than 10%, were in good agreement with those of experiments. It was demonstrated that the model was reasonable and accurate. Related Articles | Metrics Select Electrochemical Characteristics of Ti/SnO2+Sb2O3/PbO2 Anode for the Oxidation of Cr3+ in Sulfuric Acid Solution WANG Ya-qiong; CHEN Chang-ping; TONG Hong-yang; XU Wen-lin    2003, 3 (2): 0-0.   Abstract （1751）            Knowledge map    Save The pseudomonas delafieldii strain R-8 and Rhodococcus erythropolis N1-36 were used to remove the sulfur from hydrogenated diesel oil. Both strains utilize the organic sulfur compounds from diesel oils with approximate activities. Surfactants can increase the desulfurization rate. When agitating rate was 250 r/min with Tween80 present, the strain can remove 72% of the organic sulfur from low sulfur diesel oil (S<300 mg/L) in 72 h. But when sulfur concentration was higher than 1000 mg/L, the sulfur removal rate of diesel oil by strain R-8 is very low. Related Articles | Metrics Select Properties of Ionic liquids and Its Applications in Catalytic Reactions WANG Jun-feng; ZHANG Suo-jiang; CHEN Hui-ping; LI Xian; ZHANG Mi-lin    2003, 3 (2): 0-0.   Abstract （3102）      PDF （255KB）（1059）       Knowledge map    Save The progresses in the study of ionic liquids (ILs) are critically reviewed, the structure–property relationships and the basic rules are summarized. The applications of ILs in some catalytic reactions are itemized, with special attention given to metal-catalytic and bio-catalytic reactions and reaction–separation coupling processes. High activity and selectivity of enzymes are found in trace water containing or non-aqueous ILs, which may bring the breakthrough in the synthesis and catalysis. Supercritical CO2/ILs and IL/water/organic phase provide new ways for reaction– separation coupling, which may have great effects on green chemistry. Related Articles | Metrics Select Preparation of Monodisperse Silica Ultramicrons WANG Ling-lingl;FANG Xiao-longl;TANG Fang-qiong;YANG Chuan-fangl; LIU Hui-Zhoul    2003, 3 (2): 0-0.   Abstract （1658）      PDF （114KB）（641）       Knowledge map    Save The main factors that affect the leaching rate of potassium in potash feldspar were studied. It is shown that the best reaction conditions are reaction temperature of 890~950oC, size of potash feldspar ores below 0.208 mm, and the weight ratio of sodium chloride to potash feldspar ores being 1. The study showed that the leaching process is controlled by the internal ionic diffusion of Na+ and K+ in potash feldspar. The relations between diffusion coefficient and reaction temperature is expressed by the Arrhenius formula: Deff=D0exp(-–Ea/RT), with Ea = 81.42 kJ/mol, D0=0.324 mm2/h. Related Articles | Metrics Select Plasmid Stability in High Cell Density Cultures of E.coli HB101(pBR322) YU Guo-ce; JIAO Rui-shen; WANG Ji-cheng; WANG Shu-qing    2003, 3 (2): 0-0.   Abstract （2804）      PDF （139KB）（768）       Knowledge map    Save The steelmaking workshop is an important subsystem of steel manufacturing process system, the complexity of production process and difficulty of process control are the most concentrated expression on the multidimensional mass flow control in steel manufacturing process. Optimization and control in steelmaking zone is the key point of operation control in steel manufacturing process system. On the basis of summarizing research on mass flow control in several steelmaking workshops, the theoretical approach has been done for steelmaking system operating and controlling. The relationship between logic and realization for optimized running of steelmaking workshop has been deduced, and some supplement to control strategy of steelmaking workshop has also been made. Levels and guiding strategy of system optimized running have been expounded. Related Articles | Metrics Select Solvent-containing Preparative Electrophoresis of Proteins LUO Jian; LIU Zheng    2003, 3 (2): 0-0.   Abstract （1519）      PDF （129KB）（623）       Knowledge map    Save Aimed at directly mine operation conditions, WC particle/grey iron and low-chromium alloy white iron matrix composites were manufactured, and their anti-erosive wear properties were investigated against high-chromium cast iron. Results showed that the erosive wear resistance of composites with different metal matrix materials was better than that of high-Cr cast iron, and that of high-carbon and low-Cr white iron matrix was the best. Related Articles | Metrics Select Effect of Particle Size on Products from Flash Pyrolysis of Huolinhe Lignite in a Spouted-entrained Bed CUI Li-jie; YAO Jian-zhong; LIN Wei-gang    2003, 3 (2): 0-0.   Abstract （1563）      PDF （201KB）（636）       Knowledge map    Save k–e turbulence model and Ergun equation is applied to simulate the gas-flow behaviour in a Z-path-moving bed. Especially, the effect of the angle of the inclined perforated plates was investigated. The simulation result was agreed well with the experimental data, which demonstrated the reliability of the model. The simulation disclosed that, in a Z-path moving bed, with the enlargement of angle of the inclined perforated plates, the pressure drop reduced and the fact that gas flow towards the high end of the above perforated plate was enhanced. Related Articles | Metrics Select Hydrothermal Modification of Mg(OH)2 Particles in NaOH Solution XIANG Lan; JIN Yong-cheng; JIN Yong    2003, 3 (2): 0-0.   Abstract （1911）      PDF （236KB）（750）       Knowledge map    Save The hydrothermal modification behavior of Mg(OH)2 particles in aqueous NaOH solution was investigated, with focus on the influence of NaOH concentration on the morphology, crystalline structure and dispersion properties of the hydrothermal products. Regular hexagonal plates of Mg(OH)2 with uniform size and smaller specific area were formed after hydrothermal treatment. The dispersion properties of the hydrothermal products were improved owing to the alteration of growth direction for Mg(OH)2 crystals, resulting in the increase of I(001)/I(101). Under the experimental conditions (1.5 mol/L of NaOH), the increase of NaOH concentration is favorable to the hydrothermal modification of Mg(OH)2 particles. Thermodynamic calculation indicated that in the Mg(OH)2– NaOH-H2O system, the concentration of OH- ions was much higher than that of soluble Mg-bearing species [Mg(OH)2(aq), MgOH+ and Mg2+]. The improvement for the hydrothermal modification of Mg(OH)2 in the comparatively concentrated NaOH solution may be attributed to the increase of OH- concentration. Related Articles | Metrics Select Amino Acid Metabolism of Vero Cells in Batch Culture GAO Hong-liang; CONG Wei; OUYANG Fan    2003, 3 (2): 0-0.   Abstract （1877）      PDF （126KB）（682）       Knowledge map    Save Bioleaching of Ni–Cu sulfide concentrate with Acidianus brierleyi was investigated in shake flasks. The results confirmed that the most favorable conditions for Ni and Cu simultaneous dissolution were pH 1.2~1.6, inoculum 10%~20%, lower pulp density and the particle size less than 48 μm. Under the condition of 68oC, initial pH 1.6, inoculum 10%, pulp density 5%, Ni and Cu was leached 99.78% and 86.30% respectively after 4.5 d; the dissolution of Ni and Cu could be enhanced by the addition of 50~200 mg/L yeast extract and 1~5 g/L Fe3+. Related Articles | Metrics Select Catalytic Synthesis and Separation of Ethyl–glucoside TU Mao-bing; WEI Dong-zhi    2003, 3 (2): 0-0.   Abstract （1671）      PDF （190KB）（656）       Knowledge map    Save Research was undertaken to produce ethyl-glucoside by catalysis of ion exchange resin in heterogeneous systems and to determine effects of catalyst type, size, stirring speed and temperature on conversion. 89% of conversion was obtained under the conditions: temperature 78oC, ratio of resin to glucose 1:1, reaction time 20 h. The effective separation of glucoside from glucose was achieved by column chromatography. Related Articles | Metrics Select Minimum Spouting Velocity of Multi-component Particle Mixtures in a Slot-rectangular Spouted Bed WANG Bao-qun; LUO Bao-lin    2003, 3 (2): 0-0.   Abstract （1638）      PDF （213KB）（639）       Knowledge map    Save This paper is focused on the application of the portable X-ray photography technique to measurement of the radial and axial profiles of solid concentration in a gas–solids riser, a pilot-plant-scale downer, and a nano- agglomerate fluidized bed of carbon nanotubes. Twenty to thirty images with 100~200 ns X-ray pulses were processed to get a time-averaged concentration profile. Results show that this technique is a promising non-intrusive method to get time-averaged solid concentration profiles in gas–solids two phase flow systems. Related Articles | Metrics Select Effect of Nutrient Conditions on the Growth of Botryococcus braunii WANG Jun; YANG Su-ling; CONG Wei; CAI Zhao-ling    2003, 3 (2): 0-0.   Abstract （2835）      PDF （137KB）（710）       Knowledge map    Save Extracting penicillin by aliphatic alcohols was studied in this work. The aliphatic alcohols were more efficient than butyl acetate in extracting penicillin at pH=4. Mixtures of aliphatic alcohol and butyl acetate showed strong coordinated extraction effect. Aliphatic alcohols with branched chain had a little stronger ability to extracting penicillin than straight chain alcohols with the same number of carbon atoms, and water content in organic phase was reduced at the same time. Results of FT–IR indicated, that with adding of butyl acetate, hydroxyl group spectra of aliphatic alcohol became wider and shifted to higher wavenumber. It suggested that butyl acetate molecular blocked forming of aliphatic alcohol congeries, which made hydroxyl group more active. It was suggested by FT-Raman that penicillin molecule entered alcohol phase in inverse microemulsion. The branched chain of alcohols made the system more orderly and polar, which was also favorable to extraction of penicillin. Related Articles | Metrics Select Application of Stoichiometric Displacement Model for Retention to the Chromatographic Separation by Molecular Imprinting Polymer SUN Rui-feng; LUO Hui; SUI Hong-yan; SHEN Zhong-yao    2003, 3 (2): 0-0.   Abstract （1804）      PDF （499KB）（752）       Knowledge map    Save In the presence of template molecule of N-Boc-L-Tryptophan, molecular imprinting polymers (MIPs) were synthesized and evaluated by liquid chromatography. The results showed that the racemic N-Boc-Tryptophan was efficiently separated. Interaction of template molecule and stationary phase or mobile phase was analyzed with the stoichiometric displacement model for retention (SDM-R). It was showed that when absorption occurred between template molecule and MIPs, the molecule number of the displacing agent (isopropyl alcohol) released from the surface of the stationary phase was 1.2 fold that of its enantiomer, and the molecule number of the displacing agent released from a solute molecule was 1.5 fold that of its enantiomer. All these results indicated that the molecule recognition depended mainly on the structure between template molecule and MIPs. Related Articles | Metrics Select Rational Utilization of Residual Coal Gas in Iron Steel Plant WANG Li-xin; LI Xin; XU Zhi-hong; YANG Zhang-yuan    2003, 3 (2): 0-0.   Abstract （2395）      PDF （213KB）（684）       Knowledge map    Save There is currently large amount of residual coal gas in iron-steel plants which should be used in the future, otherwise it will cause energy loss and environmental pollution. It is suggested in this paper that the coal gas can be used to produce electricity or chemicals. The situation is also discussed when new technologies such as smelting reduction process and continuous casting process are adopted. Related Articles | Metrics Select Variation of Surface Tension of Sodium Aluminate Solution with Electrolytic Microstructure WANG Ya-jing; ZHAI Yu-chun; TIAN Yan-wen; HAN Yue-xin; LIU Lian-li    2003, 3 (2): 0-0.   Abstract （1599）      PDF （133KB）（654）       Knowledge map    Save In the present study, by solving turbulent flow of molten metal and inclusion trajectory, the rising velocity of inclusion in molten steel was calculated, and the behavior of moving inclusion in the slab continuous casting mould was studied numerically. The predicted result was validated experimentally. The numerical results show that the larger the diameter of the inclusion, the greater the effect of the buoyancy, the shorter the penetration depth, the less the residence time in the mould, and the higher removal rate of the inclusion. The vertical depth of the continuous Related Articles | Metrics Select Kinetics of Chemically Plating Nickel on the Surface of Hexagonal Boron Nitride Micro-particles LI Fan; ZHAO Xiao-feng; ZHANG Deng-jun; LI Bao-hou; LUO Shi-min    2003, 3 (3): 0-0.   Abstract （1842）      PDF （212KB）（722）       Knowledge map    Save The effect of inorganic salt added into aqueous fucoidan solution on fucoidan extraction was investigated. It is found that extraction of fucoidan decreases rapidly with the increase of inorganic salt concentration in the aqueous solution. Based on this phenomenon, the stripping of fucoidan was carried out with aqueous salt solution. The experimental results show that the stripping of fucoidan increases with the concentration of inorganic salt in the aqueous solution and decreases with the increase of fucoidan concentration in the organic phase. In addition, the stripping efficiency of NaCl solution is higher than that of CaCl2 solution at the same chloride ion concentration. The effect of organic solvent as diluent on the stripping of fucoidan was also studied. It is shown that the stripping of fucoidan with carbon tetrachloride as diluent is more difficult than that with the other organic solvents. Related Articles | Metrics Select Preparation of Zeolite NaA Membrane on Rough Porous a-Al2O3 Tube LIANG Yu-xiu; LU Jin-ming; LI Bang-min; WANG Jin-qu; YIN De-hong    2003, 3 (3): 0-0.   Abstract （1787）      PDF （163KB）（688）       Knowledge map    Save Thiobacillus ferrooxidans are used to leach Ni from nicopyrite.It is found that better leaching is resulted when adapted bacteria are used in contrast to unadapted bacteria. Three factors inhibit adapted and unadapted bacteria in slurry: the concentration of Ni2+ and Cu2+, the presence of sulfide, and the shearing stress. The shearing stress seems to be the most important. Related Articles | Metrics Select Kinetics on Chlorinating Rare Earth of Weishan Mid-grade Bastnasite in Shandong after Fixed Fluorine Treatment SHI Wen-zhong; ZHU Guo-cai    2003, 3 (3): 0-0.   Abstract （2645）      PDF （173KB）（727）       Knowledge map    Save The kinetics curved lines of chlorinating rate on chlorinating rare earth of Weishan mid-grade bastnasite in Shandong after fixed fluorine were determined. It is shown that the chlorinating process for fluorine-fixed calcine agreed well with the regional reaction rate model presented by Bagdasarym. The process consisted of two tandem steps, Erofeev Equation ln[–ln(1–a)]=lnk+nlnt was used to deal with the equation of reaction rate，the function between rate constant and temperature was k=2.7×107e–125900/RT. The apparent activation energy Ea was 125.9 kJ/mol. The process was mainly controlled by the interfacial chemical reaction. Related Articles | Metrics Select Composition and Distribution of Naphthenic Acids in Crude Oil of High Acid Value REN Xiao-guang; SONG Yong-ji; REN Shao-mei; QI Liang    2003, 3 (3): 0-0.   Abstract （2741）      PDF （159KB）（667）       Knowledge map    Save At the high current density of 7.5~20 A/dm2 for chromium electrowinning, the polarization curves of hydrogen evolution on a chromium electrode at the conditions of 30~55oC and pH=2.1~2.5 were obtained to explore the electrochemical process of hydrogen evolution at high current density. It was found that the potential of hydrogen evolution decreases with the increase of temperature and decrease of pH. The polarization curves are shifted toward more negative when adding (CH3)3NC16H33Br (CTMAB) in the sulfate solution. It is shown that the CTMAB can suppress hydrogen evolution moderately. When electrowinning chromium in the solution with 20 mg/L CTMAB, the current efficiency is increased by 8.1%. A series of data of over-potential on the chromium electrode at different temperatures with pH=2.1 was obtained. All the Tafle plots at different temperatures pass through a common point with the coordinate lgi equal to 1.72 and over-potential to 1.35 V. Related Articles | Metrics Select Process Engineering and Ecological Industry JIN Yong; LIU Zheng; LI You-run    2003, 3 (3): 0-0.   Abstract （1596）      PDF （7114KB）（688）       Knowledge map    Save Great contribution to the human society was made by the process industry in the past century, which, however, also resulted in serious environmental problems, hindering the sustainable development of human society. The future development of process industry should be based on a renewed infrastructure, i.e., eco-industry, in which a product-chain or product-network will be developed by incorporation of resource utilization, energy consumption and pollution control, as can be found in native ecology. Multidisciplinary research will be an essential and effective way to the development of process engineering and industry. Related Articles | Metrics page Page 1 of 3 Total 99 records First page Prev page Next page Last page