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Table of Content
05 January 2007, Volume 58 Issue 1
    综述与专论
    Progress in carbon dioxide sequestration by mineral carbonation
    BAO Weijun;LI Huiquan;ZHANG Yi
    2007, 58(1):  1-9. 
    Abstract ( 638 )   PDF (987KB) ( 408 )  
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    CO2 sequestration by mineral carbonation,namely greenhouse gas CO2 reacting with non-carbonate minerals to form geologically stable mineral carbonates,such as CaCO3,MgCO3,is a new technology for the reduction of carbon dioxide emissions to the atmosphereIn this paper,the optional resources,chemistry,thermodynamics,reaction kinetics as well as mechanisms in the mineral CO2 sequestration were analyzedMoreover,six representative process routes as well as issues of topical interest regarding the investigation of mineral sequestration were reviewedFinally,it was suggested that the integrated indirect process route using industrial solid residues should be a promising option for developing mineral sequestration.
    传递现象
    A diffusion coefficient model for polymer-solvent systems based on Simha-Somcynsky equation-of-state
    Lü Hongling;WANG Baoguo;YANG Jichu
    2007, 58(1):  10-14. 
    Abstract ( 603 )   PDF (675KB) ( 260 )  
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    With the introduction of the Simha-Somcynsky(SS)equation-of-state(EOS)into the Vrentas-Duda model,a modified diffusion coefficient model based on the EOS was developed for polymer-solvent systems.In the modified model,the measurement of polymer viscoelasticity was not required,and the parameters related to the polymer could be determined solely by the characteristic parameters of temperature and volume in the SS EOS.Therefore,it has better predictive capability compared with the original model.The calculated diffusion coefficients of benzene,toluene,ethylbenzene and chloroform in polystyrene,polyisobutylene and poly(vinyl acetate)indicated that predictions of the modified model were consistent with the experimental results.
    Meshless analysis on heat transfer with viscous dissipation in polymer flow in tube
    ZHANG Xiaohua;OUYANG Jie;ZHANG Lin
    2007, 58(1):  15-20. 
    Abstract ( 597 )   PDF (911KB) ( 419 )  
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    This paper presents the results of meshless or mesh free analysis of a heat transfer problem of polymer melt flowing in a tube at constant ambient temperature.Here, the rheological behavior of the melt was described by a temperature dependent power-law model with viscous dissipation.Temperature profiles were obtained for different tube lengths.Comparing with the no viscous dissipation model, it was shown that the temperature-dependent viscous dissipation term had significant impact on the heat transfer,i.e., the temperature difference between the model with temperature-dependent power-law viscous dissipation and the model without viscous dissipation was about 64℃.Moreover, the limiting temperature profiles of both no viscosity dissipation model and temperature-dependent power-law model were influenced by the wall boundary, but not by the inlet conditions of the polymer melt.
    Heat transfer and flow resistance characteristics of tube bundle supported by twisted-leaves
    WANG Yangjun;DENG Xianhe;LI Zhiwu;HONG Mengna
    2007, 58(1):  21-26. 
    Abstract ( 703 )   PDF (499KB) ( 577 )  
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    A new type of shell-and-tube exchanger with twisted-leaf-net support was proposed, and the heat transfer and flow resistance characteristics in the tube bundle supported by twisted-leaves for air flow in the longitudinal direction were investigated.In addition, the heat transfer enhancement of twisted-leaf 270-38.1(a type of twisted-leaf with twist angle α=270° and swirl angle β=45°), 180-38.1, 270-20.3, 180-20.3 and ring support was compared with each other.The results indicated that the comprehensive evaluation factor η of heat transfer enhancement of twisted-leaves 270-20.3 and 180-20.3 was increased by about 7% against that of the ring support, while the factor η of twisted-leaves 270-38.1 and 180-38.1 was close to that of the ring support for Reynolds number (2.5×103~2.0×104).Besides supporting the tube bundle, the twisted-leaves of 270-20.3 and 180-20.3 enhanced heat transfer obviously.The results could be used as a reference in the further research and design of the shell-and-tube exchanger.
    Relationship between strength of hydrodynamic cavitation and amount of induced hydroxyl radical
    ZHANG Xiaodong;YANG Huizhong;LI Zhiyi
    2007, 58(1):  27-32. 
    Abstract ( 635 )   PDF (537KB) ( 518 )  
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    Using the energy released in hydrodynamic cavitation to enhance some chemical reaction is a new approach to energy utilization.It is very important to establish quantitatively the relationship between the amount of hydroxyl radical induced in hydrodynamic cavitation and the strength of hydrodynamic cavitation.In this paper methylene blue was used as the catcher for hydroxyl radical induced in hydrodynamic cavitation and an ultraviolet-visible spectrophotometer was used to measure the amount of induced hydroxyl radical.The influences of upstream pipe pressure,liquid temperature and time interval on the amount of induced hydroxyl radical were also experimentally investigated.Meanwhile the suitable temperature and pressure were also established under experimental conditions.The results constituted the fundamentals to quantitatively study the strength of hydrodynamic cavitation and to effectively enhance some chemical reaction.
    Finite element analysis of transient thermal stress during cryosurgery
    ZHAO Gang;LIU Zhifeng
    2007, 58(1):  33-39. 
    Abstract ( 621 )   PDF (1836KB) ( 290 )  
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    The thermal stress fields of the target tissues during cryosurgery using two kinds of cryoprobe capable of both cooling and heating(the new type combined cryosurgery/hyperthermia cryoprobe and the Endocare cryoprobe)were studied comparatively.The intrinsic merits of the new type cryoprobe were revealed as compared with the Endocare cryoprobe from the point of view of thermal stress by studying the commonness and difference between these two kinds of cryoprobes.The enthalpy form of the classical bioheat equation coupled with the stress equations was solved by using the commercial software Ansys (version 7.0).The tissues were treated as nonideal materials freezing over a temperature range, and their thermophysical properties were taken as temperature dependent.Volumetric expansion associated with phase change of the tissue water appearing in this study was the main reason for the thermal stress concentration,and the thermal gradient might also have a minor effect on thermal stress.Thermal stress concentration would appear in the phase change region for both cryoprobes.The new type combined cryosurgery/hyperthermia cryoprobe could generate a much lower temperature and a wider frozen region,a much wider region that might experience stress concentration, and have a larger killing radius.Apparent thermal strain could be observed during the cryosurgery processes.
    Optimum configurational characteristics of transport processes and proof of transport coefficients equipartition
    ZHANG Xiaohui
    2007, 58(1):  40-43. 
    Abstract ( 589 )   PDF (326KB) ( 192 )  
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    The method and concept of a heat-engine-like plant were extended to the generalized transport processes based on the analysis of configurational characteristics of reversible heat engine and heat-engine-like plant,and a better mathematical foundation was given.It was proven by means of the variational method that the transport coefficients equipartion was the basic characteristics of a linear transport process system which pursued entropy production minimization when the material was subjected to overall constraints.The new idea of optimum configurational characteristics was preliminarily verified.
    多相流
    CFD-DEM simulation of clustering phenomena in riser and downer
    ZHAO Yongzhi;CHENG Yi;JIN Yong
    2007, 58(1):  44-53. 
    Abstract ( 672 )   PDF (7613KB) ( 362 )  
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    Based on the micro-scale flow mechanism,a method combining computational fluid dynamics (CFD) and discrete element method (DEM) was established to simulate the gas-solid flow systems in the 2-dimensional riser and downer.Periodic boundary conditions were employed in the simulations,in which particles with mean diameter of 520 μm and density of 2620 kg·m-3 were used.The results qualitatively or semi-quantitatively disclosed the different particle clustering phenomena on the micro-scale in the co-current gas-solid flows against or along the gravity direction.In the riser,severe particle clustering existed and the particles in clusters showed evident backmixing.While in the downer,rather loose clustering was observed and the particles in clusters flowed in the same direction as the macro-flow.Backmixing of particles could hardly be found in the downer.Ensemble-averaged macro-flow behavior, including the distributions of gas and solids velocities and concentrations, were obtained statistically, which had qualitative agreement with the experimental data in the literature.
    Micro-bubble controlled growth in rectangular microchannel of micro-electro-mechanical systems
    DONG Tao;YANG Zhaochu;BI Qincheng;ZHANG Yulong;GU Dandan;ZHANG Chunquan
    2007, 58(1):  54-60. 
    Abstract ( 636 )   PDF (1911KB) ( 254 )  
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    With the silicon microfabrication process, six micro-electro-mechanical systems(MEMS) devices for exploring micro-bubble growth were designed and fabricated.Experimental investigations of micro-bubble growth in micro restrained space were performed.The results showed that the micro-bubble growth rate was influenced by heat power, dimensions of microheater, microchannel section, microfluidic velocity, and materials of the fluid.A higher heating voltage resulted in faster bubble growth.The width of heating pulse took effect during the latter period of bubble growth.Under the same heating voltage and pulse width, a larger width of the microheater led to faster bubble growth.When the aspect ratio of the microchannel section was over 1.0, a smaller aspect ratio brought on slower bubble growth during the latter period.The larger the microfluidic velocity, the later the bubble growth start point, and the slower the bubble growth.Under the same test condition, the bubble growth rate of R113 was the largest among the three working fluids, followed by FC-72 and deionized water, due to the effect of thermophysical parameters of the fluids.
    Void fraction measurement of oil-gas two-phase flow based on ant system and electrical capacitance tomography
    LI Qiangwei;HUANG Zhiyao;WANG Baoliang;LI Haiqing
    2007, 58(1):  61-66. 
    Abstract ( 653 )   PDF (521KB) ( 330 )  
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    A new method based on electrical capacitance tomography (ECT) in conjunction with the ant system was proposed to measure the void fraction of oil-gas two-phase flow.The 12-electrode capacitance sensor of ECT system could obtain 66 measured capacitance values.The void fraction measurement model parameters f and b, which were obtained by the least square method in advance, were determined according to the flow pattern that was first identified by the ECT system.Then the most important combined capacitance set which had decisive influence on the void fraction of a given state of measurement was obtained based on the ant system, and the corresponding pheromone of the ant system was regarded as the weight of this set.The capacitance set and its weight were simultaneously input to the measurement model to obtain the void fraction.The experimental results showed that the proposed method for the void fraction measurement was effective under different flow patterns owing to avoidance of complex image reconstruction and good real-time performance.The maximum error was less than 5.5% as compared with the quick closing valve method, and the measurement time was within 0.08 s.
    Solid particle velocity measurement based on spatial filtering effect of electrodynamic sensor
    XU Chuanlong;TANG Guanghua;HUANG Jian;YANG Daoye;ZHOU Bin;WANG Shimin
    2007, 58(1):  67-74. 
    Abstract ( 537 )   PDF (639KB) ( 601 )  
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    Particle velocity is an important parameter describing the flow state of gas-solid two-phase flow.A measurement method of solid particles mean velocity based on the spatial filtering effect of the electrodynamic sensor was developed.The spatial filtering characteristics of the electrodynamic sensor were described quantitatively,from which the relationship between the frequency characteristics of the output signal of the electrodynamic sensor and particle velocity was obtained.The effects of geometry parameters of the sensor,particle velocity distribution,particle concentration distribution in the pipe cross section,particle size,particle type and frequency resolution on the measurement of particles mean velocity were also investigated.Off-line experimental results in a gravity-fed particles flow apparatus were presented.The measurement method was verified by the fundamental theoretical and experimental results.
    Determination of stable zone and related factors in magnetically fluidized bed
    WANG Yinghui;GUI Keting;SHI Mingheng
    2007, 58(1):  75-79. 
    Abstract ( 785 )   PDF (461KB) ( 263 )  
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    Experimental research on the fluidized characteristics of four magnetic particles with different average diameters (from 213 μm to 512 μm) was carried out in this study.The effects of such factors as intensity of the magnetic field and diameter of the particles, on the stable zone in the magnetically fluidized bed were investigated and discussed.Based on the experiments,by using the dimensionless analysis method, an experimental correlation to calculate the stable zone with three dimensionless numbers, i.e. the ratio of magnetic potential to gravity potential Er, Archimedes number Ar and Reynolds number Re, was proposed.In addition, the level of significance of the correlation was tested, and the results showed that the most significant factor to influence the stable fluidization zone was Er, and Ar was the second, while Re was the least significant factor.
    催化、动力学与反应器
    Hydroisomerization of n-heptane over bimetal-bearing SO2-4/ZrO2 catalysts supported on USY zeolite
    WEI Ruiping;WANG Jun;GU Yanbo
    2007, 58(1):  80-85. 
    Abstract ( 805 )   PDF (446KB) ( 379 )  
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    The bimetal-bearing SO2-4/ZrO2 superacid catalysts supported on ultra stable Y(USY) zeolite were prepared by impregnation and characterized with XRD and H2-TPR.Their catalytic activities were evaluated in the hydroisomerization of n-heptane with an atmospheric fixed-bed reactor.The USY support well kept its pore structure in catalysts and the metal species were highly dispersed on the support.The Pt-bearing catalysts doped with Cr or Al were catalytically much more stable and exhibited higher catalytic activity and selectivity than the catalysts without dopants.Over the catalyst with a Pt loading of 0.4%(mass) and ZrO2 loading of 10%(mass), the conversion of n-heptane was 42.1% with a selectivity of only 69.6% for isomerization products, while over the catalysts doped with Cr or Al with a molar ratio of Cr(Al) to Pt 5∶1, the conversion of n-heptane was 44.3% and 42.1% with the selectivity for isomerization products as high as 88.9% and 89.5% respectively.
    Establishment of 14 lumps model for fluid catalytic cracking of hydrotreated residuum
    WANG Jianping;XU Xiankun;WENG Huixin;FANG Xiangchen;HU Changlu;HAN Zhaoming
    2007, 58(1):  86-94. 
    Abstract ( 840 )   PDF (510KB) ( 329 )  
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    According to the commercial data of 3# residual fluid catalytic cracking(RFCC) processing hydrotreated residuum in Maoming Petrochemical Company and the characteristics of hydrotreated residuum,a kinetic model with 14 lumps for hydrotreated residuum fluid catalytic cracking based on the SARA composition of the residuum stock was established.Its kinetic parameters were determined by the stepwise-method.The results were verified with commercial data,which showed that the model could predict not only the distribution of products, but also the quality of the main products and describe the reaction process of hydrotreated residuum fluid catalytic cracking.The model could be useful in optimizing the operation of a commercial unit.
    Evaluation of iron catalyst coupled with ruthenium tandem catalyst in ammonia synthesis
    WANG Rong;LIN Jianxin;YU Xiujin;NI Jun;WEI Kemei
    2007, 58(1):  95-101. 
    Abstract ( 708 )   PDF (485KB) ( 307 )  
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    In the laboratory and the side draw test unit of a commercial ammonia synthesis reactor,the performance of the FA-Ru catalyst and the A202 iron catalyst was compared,and the influence of the iron catalyst coupled with ruthenium catalyst and the single iron catalyst on ammonia synthesis was investigated.Experiment results showed that the activity of the FA-Ru catalyst for ammonia synthesis was higher than the A202 catalyst by 44%—75% at low temperature(375—425℃),low pressure(10—15 MPa), low H2/N2 ratio and high concentration of ammonia synthesis gas(10%—16%, vol)in the laboratory.Ammonia conversion was higher than that of the single iron catalyst by 24.5%—44.8% and increased with increasing ruthenium catalyst loading in mixed catalyst bed under laboratory condition.Similarly, ammonia conversion was higher than that of the single iron catalyst by 27.7%—58.8% and increased with increasing ruthenium catalyst loading in tandem with iron catalyst under laboratory condition.The reaction temperature of ruthenium catalyst bed might be lowered to 400℃ when ruthenium catalyst loading reached above half of the iron catalyst.Side draw experiments showed that ammonia conversion of FA-Ru catalyst at 13.0 MPa and 10000—15000 h-1 might achieve the level of the single iron catalyst at 26 MPa for the same space velocity.Ammonia conversion of iron and ruthenium catalysts in tandem was 43%—56% higher than that of the single iron catalyst,depending on the operation condition.
    Comparison of fluidized and fixed bed operations for hydrogen production from methane decomposition
    LIU Shaowen;LI Yongdan
    2007, 58(1):  102-107. 
    Abstract ( 833 )   PDF (1218KB) ( 500 )  
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    The effect of reaction modes, i.e.fluidized bed and fixed bed operations, on catalyst life for hydrogen production from methane decomposition was investigated over a 75Ni15Cu10Al catalyst and a 2Co1Al catalyst.Pure methane was used as the feed.The results showed that the apparent reaction rate in the fluidized bed was much higher than that in the fixed bed, indicating that in the fixed bed the reaction was transport-controlled.The carbon formed was characterized with TEM technique, and the results showed that the size of metal particles increased with rising reaction temperature, and at the same reaction temperature the size of metal particles on the catalyst in the fixed bed was larger than that on the catalyst in the fluidized bed, signifying that fluidized bed reactor is beneficial to preventing the sintering of active metals.
    Anti-oxidation property of 3,7-di-iso-octyl-phenothiazine in lubricants
    WANG Hui;WU Zuwang; LI Chuncheng;WU Fuli;SUN Jie
    2007, 58(1):  108-113. 
    Abstract ( 922 )   PDF (786KB) ( 670 )  
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    The anti-oxidation performance of 3,7-di-iso-octyl-phenothiazine was measured in group Ⅰ,Ⅱ and Ⅳ base oils by rotating pressure vessel oxidation testing(RPVOT),pressure differential scanning calorimetry(PDSC)and aging test, and its synergistic effect with 4,4′-di-iso-octyl-diphenylamine was examined. The results indicated that 3,7-di-iso-octyl-phenothiazine showed longer oxidation induction period and lower acid number increase than 4,4′-di-iso-octyl-diphenylamine, and their notable synergistic effect was observed. It was found that the anti-oxidation characteristics of the above-mentioned antioxidants were strongly affected by the composition of the corresponding base oil.
    分离工程
    Mechanism and model of chiral separation of tryptophan by ultrafiltration using BSA (Ⅰ)
    CHEN Yang;Lü Yangcheng;QI Xuan;LUO Guangsheng
    2007, 58(1):  114-118. 
    Abstract ( 649 )   PDF (1226KB) ( 293 )  
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    Chiral separation of tryptophan(Trp) by ultrafiltration using bovine serum albumin (BSA) as the selector realized good separation result.The influence of pH value, temperature, initial concentration of tryptophan and BSA as well as the pressure difference of ultrafiltration on the chiral separation process was examined systematically in the present work.The experimental results showed that the influence of pH and temperature on the process was significant.The mechanism of chiral separation was analyzed qualitatively and the influence of pH and temperature was discussed in view of the conformation of BSA and electric charge of tryptophan in the solution, because pH value and temperature played critical roles in the conformation of BSA and electric charge of tryptophan.
    Mechanism and model of chiral separation of tryptophan by ultrafiltration using BSA(Ⅱ)
    QI Xuan;Lü Yangcheng;CHEN Yang;LUO Guangsheng
    2007, 58(1):  119-124. 
    Abstract ( 649 )   PDF (999KB) ( 193 )  
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    In order to accurately predict the effect of chiral separation, this work obtained several complexation constants from a large number of singular tryptophan (Trp) enantiomer experiments and compared three models of complexation mechanism of tryptophan to bovine serum albumin (BSA).In the pH range from 7 to 12, the complexation mechanism was a competitive binding of D- and L-tryptophan on a single site.Complexation constants (KD and KL) varied significantly by changing pH in the solution and the variation of KD and KL was caused by the change of conformation of BSA and electric charge characteristics of Trp.The model could well predict the concentration of D-tryptophan in the permeated solution and separation factor.The calculation equation of complexation constants was given by regressing experimental data to a certain function.
    Properties of D-tryptophane molecular imprinting composite membranes and its preparation
    YANG Zuoguo;XU Zhenliang;Chen Gui’e;XIE Yizhang
    2007, 58(1):  125-129. 
    Abstract ( 613 )   PDF (592KB) ( 260 )  
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    Using polysulfone (PSF) hollow fiber membrane as the supporting membrane, chiral (D-tryptophane) molecular imprinted hollow fiber composite membrane (CMIHFCM) was fabricated by the surface photo-polymerization method and the recognition ability of CMIHFCM for D,L-tryptophane was studied.After surface polymerization, the external surface of CMIHFCM had a complex network layer with a thickness of 3 μm on the supporting membrane.The experimental results showed that CMIHFCM had the recognition ability for the template D-tryptophane.The D- tryptophane solution could be condensed more significantly by the molecular imprinted membrane than L-tryptophane,and the separation factor (α) of D- tryptophane (D-Trp) and L-tryptophane (L-Trp) could be 5.0.However, the recognition for D-tryptophane by the non-molecular imprinted membrane was weaker.When the concentration of initiator was 1.0%, CMIHFCM with good recognition ability for D-Trp was obtained.
    Modeling water vapor permeation through hollow fiber composite membrane
    ZHAO Suying;SUN Yanhui;WANG Liang’en
    2007, 58(1):  130-135. 
    Abstract ( 581 )   PDF (453KB) ( 528 )  
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    A differential resistance model was established to describe the permeation of water vapor across the hollow fiber composite membrane.The reliability of the model was verified by experiment.The configuration parameters of the hollow fiber membrane employed in the experiment were calculated with this model.The resistance of each layer to water vapor was also studied.The influences of membrane configuration parameters on selectivities of H2O/C2H2 were discussed.
    Effects of cellulase on extracting isoflavone from soybean residue
    CHEN Qingqing;XIA Liming
    2007, 58(1):  136-140. 
    Abstract ( 951 )   PDF (434KB) ( 360 )  
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    Soybean residue from soybean oil manufacturers can be used to extract isoflavone.Soybean residue was pre-hydrolyzed by cellulase from different microbes, then the hydrolyzate was obtained and the solid residue was extracted by using 70% ethanol.When using the cellulase from Bacillus sp ZU-4,the isoflavone yield was 1.4 times as that by normal ethanol extraction and the isoflavone composition was unchanged.When using the cellulase from Aspergillus niger ZU-7,the isoflavone yield was not increased but glucoside isoflavones were transformed to aglycones.By pre-hydrolysis with cellulase from Trichoderma reesei ZU-5, the isoflavone yield was increased by 1.6 times and at the same time the isoflavone composition was transformed to aglycones with higher physiological activity.The optimal dosage of cellulase from Trichoderma reesei ZU-5 was 15 FPIU(Filter Paper International Units)·(g soybean residue)-1 and the treating time was 36 h.When selecting macroporous resin for isoflavones absorption and desorption,the macroporous resin with weak polarity was proper for purifying aglycone isoflavones.
    Mechanism of NMA as entrainer in separating acetic acid from water with extractive distillation
    LI Xinli;TANG Congming;GUAN Guofeng
    2007, 58(1):  141-144. 
    Abstract ( 697 )   PDF (482KB) ( 221 )  
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    N-methylacetamide(NMA) was used as entrainer in separating acetic acid from water with extractive distillation, and the interaction mechanism in this process was studied by using the density functional theory.The optimization geometries and vibration frequencies of NMA-acetic acid and NMA-water complexes were calculated at the B3LYP/6-311G(d,p) level.After the basis set superposition error (BSSE) correction and the zero point vibration energy (ZPE) correction, the interaction energies for three types of NMA-acetic acid complexes and one type of NMA-water complex were -44.3,-35.5,-32.4 and -16.0 kJ·mol-1 respectively, which showed that NMA had a great affinity for acetic acid than water.The boiling point of the NMA-acetic acid complex was higher than that of acetic acid so that acetic acid is easily preserved in the liquid phase, which is in agreement with the VLE experiment for NMA+acetic acid+water system that gave a relative volatility of 3.0—4.0.The results of natural bond orbital (NBO) population analysis revealed that there was charge-transfer in the complex formation, and acetic acid acted as electron acceptor during this transformation.
    Adsorption models for heavy metal biosorption
    ZHENG Cheng;YU Qiming;YIN Pinghe
    2007, 58(1):  145-148. 
    Abstract ( 687 )   PDF (266KB) ( 200 )  
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    Heavy metal biosorption is an effective process for the removal and recovery of heavy metal ions.Equilibrium isotherms obtained experimentally are usually correlated empirically with commonly used adsorption models, without considering the underlying mechanisms of biosorption.Commonly used models for correlating biosorption isotherm data are briefly reviewed and the use of the adsorption models in correlating the desorption processes is analysed.A set of biosorption/desorption experiments for a marine alga derived biosorbent are carried out to test the use of the adsorption models in the desorption process.Experimental data indicate that the amount of the heavy metal ions desorbed from the biomass could not be calculated with the adsorption models.This suggests that the empirical use of adsorption models in the correlation may not be valid when the reversibility of the biosorption equlibrium in the desorption process needs to be considered.Therefore, mechanism based biosorption models are needed for better correlation of equilibrium isotherm data.
    过程系统工程
    Develop p-xylene oxidation reaction model based on MLFN-PLSR
    YAN Xuefeng
    2007, 58(1):  149-154. 
    Abstract ( 1431 )   PDF (464KB) ( 191 )  
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    Due to the fact that there exist many factors having highly-nonlinear and complex effects on the concentration of 4-carboxybenzaldehyde (4-CBA),the most important intermediate product of p-xylene (PX) oxidation reaction, a novel approach integrating multi-layer feedforward network (MLFN) with partial least squares regression (PLSR) was proposed to develop a model of 4-CBA concentration in the PX oxidation product.A three-layer network consisting of an input layer, a single hidden layer and an output layer was selected by MLFN-PLSR and the number of the hidden layer nodes was as large as possible.Firstly, MLFN learned from the training sample.Secondly, PLSR was used to identify PLS components from the hidden-layer node output and remove the correlation among them.And, an optimal prediction ability model with the optimal number of the latent variables was obtained according to the prediction ability of the model for the verified sample.The comparison results showed that the prediction ability of the optimal MLFN-PLSR was 12.11% higher than that of the optimal MLFN and 70.62% higher than that of the optimal PLSR, and the mean prediction ability of MLFN-PLSR was 8.37% higher than that of MLFN.
    Simulation and analysis of energy optimization for PEMFC hybrid system
    LIU Chengze;ZHU Xinjian;Cao Guangyi
    2007, 58(1):  155-160. 
    Abstract ( 582 )   PDF (528KB) ( 329 )  
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    The control objective and several key parameters of PEMFC(proton exchange membrane fuel cell)hybrid system were analyzed.Control strategy design and energy optimization simulation were made individually for a given cycle and real time operation.For the given cycle case,genetic algorithm was adopted to solve the multi-constraint combinatorial optimization problem.The simulation result showed the algorithm’s feasibility.As far as the real time operation was concerned,based on the original fuzzy control strategy,the fuel cell voltage and voltage variance parameters were introduced to apply two-level modification on the fuzzy control output.The result revealed that the improved fuzzy control strategy could enhance fuel cell efficiency and reduce power fluctuations.
    Single contaminant water network design for batch processes
    YANG Xia;YUE Jincai;BI Rongshan;LI Yugang; ZHENG Shiqing
    2007, 58(1):  161-167. 
    Abstract ( 527 )   PDF (473KB) ( 293 )  
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    A new time-purity two-dimensional water-using diagram was presented to synthesize water network for batch processes. In the diagram y-axis was water purity and the x-axis was time.Design rules with or without storage tank were presented respectively.The diagram could clearly describe water-using batch processes.The method firstly determined the pinch point and the minimum utility targets of the batch processes by the water cascade analysis technology, then synthesized the water network by using the diagram and rules, and then determined the number and volume of storage tanks for batch processes with storage tanks,and lastly described the synthesized optimum water network by the time-water network diagram.The influence of the water network by the flowrate demand of a water-using process was also discussed.Calculation of two literature examples showed that the method was easy, effective and efficient.
    Optimization of gasoline blending and scheduling in refinery complexes
    ZHANG Bingjian;HUA Ben;CHEN Qinglin
    2007, 58(1):  168-175. 
    Abstract ( 722 )   PDF (484KB) ( 279 )  
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    Gasoline blending and scheduling is the last and important operation in a refinery.It is also the last chance to improve the quality of products and to reduce the production costs.Firstly, a novel mixed integer nonlinear programming (MINLP) formulation based on continuous time representation, is presented in this paper.Gasoline blending and short-term scheduling are integrated in the proposed model to optimize blending and scheduling simultaneously, and a nonlinear blending model is employed to reduce the quality excess of gasoline products.Empirical knowledge and some effective sets are added to the model to reduce the model scale and to improve the solve performance.A novel algorithm for the presented model is proposed.A series of mixed integer linear programming (MILP) model is solved instead of solving the original MINLP problem directly.Finally, a real industrial example, provided by a refinery complex, is used to demonstrate the performance of the presented model and algorithm.The model can get the optimal results in a reasonable time, which is more profitable than the conventional or other methods.
    Optimization of fermentation conditions for α-chloropropionic acid dehalogenases production based on response surface analysis
    WANG Nengqiang; WU Jianping; ZOU Xiaoming ; WANG Pu; YANG Lirong
    2007, 58(1):  176-180. 
    Abstract ( 676 )   PDF (795KB) ( 348 )  
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    Two level factorials designs of Plackett-Burman were constructed to select the Pseudomonas W20 fermentation medium components of α-chloropropionic acid dehalogenases.Three important components were urea, glucose and KH2PO4.The optimized levels of these factors were determined by the response surface analysis. The results showed that the optimum concentrations of urea,glucose and KH2PO4 were 1.19 g·L-1,18.4 g·L-1 and 1.30 g·L-1 respectively.The enzyme activity increased by 23.77% under the optimized condition.
    表面与界面工程
    Stabilizer distribution on surface of solid lipid microparticles and SLM stability: mesoscale simulation and experiments
    ZHANG Lijuan;LONG Chunxia;QIAN Yu;LIU Lei
    2007, 58(1):  181-189. 
    Abstract ( 859 )   PDF (6682KB) ( 447 )  
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    Dissipative particle dynamics (DPD) simulation was used to model the distribution of stabilizers (lecithin,poroxamer and PVA)on the surface of ibuprofen-loaded solid lipid microparticles (SLM).It was shown from DPD simulation results that lecithin totally enwrapped the surface of SLM when the molar fraction of ibuprofen was 1% and 2%.However, when the molar fraction of ibuprofen was increased to 3% and 5%, lecithin could not cover the place with a higher concentration of ibuprofen molecules.Poloxamer 407 and PVA totally enwrapped the surface of SLM when the molar fraction of ibuprofen was increased from 1% to 5%.The experimental results could be interpreted with the simulation results.DPD simulation provides an insight into the microstructure of a drug carrier and helps to analyze the experimental results, which is helpful in stabilizer selection for SLM.
    Corrosion inhibition of low phosphonic copolymer on brass
    WANG Chen;LI Tianduo;LI Shuping;SONG Cunyi
    2007, 58(1):  190-194. 
    Abstract ( 619 )   PDF (894KB) ( 238 )  
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    The corrosion inhibition of brass by a low phosphonic copolymer in the artificial cooling water was investigated with weight loss measurements, energy-dispersion X-ray analysis(EDX) and electrochemical tests.The surface elemental compositions of the tested brass specimens without and with the copolymer inhibitor were analyzed, and the inhibition mechanism was studied.The results showed that the adsorption of the low phosphonic copolymer on the reactive sites of the brass specimen surface inhibited the anodic reaction.
    生物化学工程、制药、食品和天然产物加工
    Effect of recycles of Candida glycerinogenes cells on glycerol production
    XIE Tao;FANG Huiying;RAO Zhiming;ZHUGE Jian
    2007, 58(1):  195-199. 
    Abstract ( 762 )   PDF (815KB) ( 171 )  
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    Glycerol production by reusing free Candida glycerinogenes cells in repeated batch fermentation was studied.The results showed that the suitable concentration of KH2PO4 in the re-inoculation medium was 0.1 g·L-1, lower than KH2PO4 of 0.4 g·L-1 in the first fermentation medium.When the residual glucose concentration decreased to 10 g·L-1, yeast cells from sterile centrifugation with the activity high enough for the next cycle could be directly recycled for the next batch fermentation.After 15 cycles of re-inoculation, average glycerol concentration, yield and productivity were 138.69 g·L-1, 60.17% and 2.31 g·L-1·h-1, with an increase of 15.74%, 15.48% and 39.16%, respectively, compared with these in the first batch fermentation.Although yeast cells decayed severely in the fifteenth cycle, 12—14 cycles of repeated batch fermentation were possible.
    Synthesis of Fusukang by solid-phase synthesis
    GUO Yiqiong;ZHAO Jiong;GAN Yiru
    2007, 58(1):  200-204. 
    Abstract ( 658 )   PDF (648KB) ( 463 )  
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    9-Fluorenyl methoxy carbonyl(Fmoc)solid-phase synthesis of Fusukang was studied firstly, including stepwise solid-phase peptide synthesis(SPPS) and solid-phase convergent synthesis.The SPPS methodology utilized DMF as the coupling solvent, HBTU/HOBt/DIEA as the coupling reagent, Wang resin as solid supporter, TFA/p-methyl phenol/EDT/H2O(97∶0.25∶0.25∶2.5) as the cleavage condition, with 2-fold equivalent molar excess of protected amino acid.In the Fmoc solid-phase convergent synthesis of Fusukang, the effects of convergent protocol, coupling solvents, and coupling reagents on the yield of Fusukang were systemically studied, and the protocol of condensation process was optimized, i.e.using the sequential condensation of four protected peptide segments(1—10,11—20,21—25,26—36) with 1.5-fold equivalent molar excess of protected peptide segments in solvent; HATU/HOAt/DIEA (4-fold equivalent) as the coupling reagent; mixture DMF/DCM(1∶1,vol) as the coupling solvent; TFA/p-methyl phenol/EDT/H2O (97∶0.25∶0.25∶2.5) as the cleavage condition, washing resin 5 times with DCM before and after each reaction.The yield of crude Fusukang was 67.31% , and the purity was 38.75%.
    能源和环境工程
    Two-phase anaerobic digestion process for treating high concentration sulfate-organic wastewater with jet-loop anaerobic fluidized bed reactor
    WEI Chaohai;WANG Wenxiang;WU Chaofei
    2007, 58(1):  205-211. 
    Abstract ( 484 )   PDF (1296KB) ( 705 )  
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    Jet-loop anaerobic fluidized bed (JLAFB) was designed as a new anaerobic reactor.Two-phase anaerobic digestion process with JLAFB and AGSFB (anaerobic granular sludge fluidized bed) as acidogenic phase (or sulfate-reducing phase) and methane-producing phase, respectively, was used to treat high concentration sulfate-organic wastewater.With the successful culture of acid-tolerant sulfate reducing anaerobic granular sludge, the process successfully separated sulfate reducing bacteria (SRB) and methane producing bacteria (MPB) in different phases, and avoided substrate competition inhibition on MPB by SRB.When influent SO2-4 loading rate was up to 12.0 kg SO2-4·m-3·d-1, the sulfide concentrations of JLAFB and AGSFB reactors were 78.3 mg·L-1 and 92.4 mg·L-1, respectively, that were far less than 200 mg·L-1 of inhibition value, which avoided the accumulation of sulfide and toxicity inhibition on microorganisms in reactors.When the influent COD and SO2-4 loading rates during smooth operation were 26.0 and 8.5 kg SO2-4·m-3·d-1 respectively, the total removal efficiency values of COD and SO2-4 were 86.9% and 97.6% respectively.The optimal process conditions of the treating system were:influent COD/SO2-4 ratio>3.0,influent alkalinity was 400—500 mg·L-1,aeration gas flow rate and hydraulic recycle ratio of JLAFB were 0.04 L·min-1and 5∶1 respectively.
    Influence of structural parameters on ordered cathode catalyst layer in proton exchange membrane fuel cells
    DU Chunyu;CHENG Xinqun; YIN Geping;SHI Pengfei
    2007, 58(1):  212-216. 
    Abstract ( 481 )   PDF (817KB) ( 385 )  
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    A steady-state numerical model was developed for an ordered cathode catalyst layer of proton exchange membrane fuel cells.The governing equations account for proton and electron transfer, oxygen diffusion and electrochemical reaction kinetics.The simulation results were consistent with the experimental data.The dependence of the ordered catalyst layer (OCL) performance on structural parameters was investigated.It was revealed that the OCL performance was much sensitive to electrolyte volume fraction and platinum loading, and there were optimal values above which the performance dropped quickly.Carbon support with a smaller diameter and thickness is beneficial to the OCL performance.
    Release behavior of hydrocarbon components of superfinepulverized coal pyrolyzed under reburning conditions
    JIN Jing;ZHANG Zhongxiao;ZHANG Jianmin
    2007, 58(1):  217-221. 
    Abstract ( 563 )   PDF (422KB) ( 235 )  
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    The release behavior of hydrocarbon components of superfine pulverized coal pyrolyzed under reburning conditions was investigated by means of pipe furnace and gas chromatography.The test results showed that the main component of pyrolysis gas was CH4,and other components,such as C2H4,C2H6,C3H6,C3H8 and C4H10were relatively less.The amount of released hydrocarbon components of Longkou lignite is the greatest,that of Shenfu bituminous coal was the second,and that of Jincheng anthracite was obviously less than that of the above two.The release amount of hydrocarbon components increased with the decrease of particle size.But as the particle size decreased to a critical value,the release amount of hydrocarbon components no longer increased obviously.With Longkou lignite and Shenfu bituminous coal as reburning fuels,the NOx reduction efficiency could be enhanced because the amount of released hydrocarbon components in the volatile matter increased.
    Pyrolysis properties of simulated transfusion tube
    ZHU Hongmei;YAN Jianhua;SHEN Xiaojiang;JIANG Xuguang;CEN Kefa
    2007, 58(1):  222-226. 
    Abstract ( 612 )   PDF (482KB) ( 296 )  
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    A non-stoichiometic equilibrium model based on the Gibbs free energy minimization approach was developed to analyze the pysolysis of typical medical waste-transfusion tube.The equations of pyrolysis products distribution were established on the basis of equilibrium analysis.Also the reliability of these equations was verified by experimenting on the hazardous waste rotary kiln.These equations could be used to predict distribution of pysolysis products directly.
    Characteristics of NOx emission of incineration test of chemical organic waste liquid in CFB
    CHEN Huichao;ZHAO Changsui;LI Yongwang;LU Duanfeng;LI Qingzhao;CHEN Xiaoping;YANG Linjun;WU Xin
    2007, 58(1):  227-232. 
    Abstract ( 613 )   PDF (472KB) ( 242 )  
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    An incineration test of the toxic chemical organic waste liquid(red waste liquid) was conducted in a circulating fluidized bed (CFB) incinerator.The flue gas was measured online with the advanced SAE-19 flue gas analyzer.The effects of several factors, in terms of the flowrate of red waste liquid, the ratio of red waste liquid injected into the dense bed of the CFB, the excess air coefficient and the secondary air fraction on NOx emission were investigated.The experimental results showed that NOx concentration in flue gas increased with the increase in the flowrate of red waste liquid injected into the bed or the excess air coefficient,and decreased with the increase in the ratio of red waste liquid injected into the dense bed of the CFB or the secondary air fraction.During the test runs, NOx concentration in flue gas meets the national standard for NOx emission due to the suppression effect of low temperature and staged combustion in the CFB on NOx formation.
    Effect of phospholipids and water contents on production of bio-diesel fuel catalyzed by lipases in a solvent system
    LI Zebo;DU Wei;LIU Dehua
    2007, 58(1):  233-237. 
    Abstract ( 679 )   PDF (469KB) ( 437 )  
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    tert-Butanol,as a novel reaction medium,was adopted for lipase-catalyzed trans-esterification of rapeseed oil for bio-diesel production,and the negative effects caused by excessive methanol and by-product glycerol could be eliminated.When the water content reached 2% or phospholipids content was more than 0.1% based on the oil mass,there would be obvious negative effects on lipase LipozymeIM TL and Novozym 435.Combined use of LipozymeIM TL and Novozym 435 was proposed further to catalyze the methanolysis,and the water-resistant and phospholipids-resistant abilities of the lipases could be improved.
    材料科学与工程
    Rheological property of nanometer calcium carbonate composite acrylic coatings
    WANG Xunqiu;JIANG Denggao
    2007, 58(1):  238-247. 
    Abstract ( 646 )   PDF (3569KB) ( 265 )  
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    Nano-CaCO3 (nanometer calcium carbonate) composite acrylic coatings were prepared, and their application performance was tested.The result indicated that when the dosage of the modified nano-CaCO3 was 1.5%(mass), the coatings were obviously improved in such properties as light resistance, water resistance, self-cleaning and storage stability.The effects of adding light calcium carbonate, unmodified nano-CaCO3, modified nano-CaCO3 into the acrylic coatings and its dosage on the rheological property were studied.The results showed that the rheological property of this system conformed to the Casson model.When the dosage of modified nano-CaCO3 was 1.5% (mass), the coatings showed lower viscosity sensitivity to temperature, decreased viscosity, strong shear thinning ability,low Casson yield stress, and increased thixotropy, and the performance improvement was basically consistent with the change in rheological property.In addition,changing the solid content or adding butyl alcohol had basically the same influence on the rheological property of modified nano-CaCO3 composite acrylic coatings and the traditional acrylic coatings.
    Effect of processing conditions on residual stress and shrinkage in injection molding
    XI Guodong;ZHOU Huamin;LI Dequn
    2007, 58(1):  248-254. 
    Abstract ( 706 )   PDF (2088KB) ( 845 )  
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    In injection molding, the residual stress and shrinkage of the product are affected by processing conditions directly.A detailed linear thermoviscoelastic model was developed to calculate thermally and pressure induced residual stress and shrinkage in amorphous plastic parts.A systematic study on the effect of processing conditions on shrinkage and residual stress was made for PS and ABS.The results showed that the shrinkage for amorphous polymers was constant along the flow path, and the residual stress distribution through the thickness was almost the same in the flowpath, with a little higher stresses near the end.It indicated that the holding pressure was the key parameter, an increase in holding pressure and melt temperature caused a decrease in shrinkage and the effect of mold temperature on the shrinkage was much smaller.
    Optimizing sink marks of ABS part with ribs by gas assisted injection
    DONG Binbin;LI Qian;LIU Chuntai;SHEN Changyu
    2007, 58(1):  255-259. 
    Abstract ( 778 )   PDF (922KB) ( 192 )  
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    Gas assisted injection molding (GAIM), as an innovative molding technique, has received extensive attention in recent years.GAIM can effectively decrease sink marks and volumetric shrinkage of the part,while GAIM is inherently more complex than conventional injection molding.At the same time, it involves many additional process parameters, such as gas delay time, gas pressure and gas injection time.In this study gas channels supplant ribs were used to achieve stable and smooth surface quality.In order to find optimum process parameters of GAIM, the experimental design of the Taguchi method was used to determine the GAIM conditions, and the cases were simulated by using the integrated commercial software packages.All molding conditions and affecting factors were discussed regarding the depth of sink marks of the shell of a machine.The results showed that the gas channels supplant ribs can effectively reduce raw material consumption, eliminate sink marks, diminish differential shrinkage and residual stress, improve finish surface, and enhance stability of part dimension.
    现代化工技术
    Electrochemical reduction of m-nitrobenzoic acid in sulfuric acid
    MA Chun’an;WANG Xiaojun;LI Meichao;TANG Junyan
    2007, 58(1):  260-264. 
    Abstract ( 652 )   PDF (485KB) ( 377 )  
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    The influences of electrode material, scan rate, reaction temperature and additive on the electrochemical reduction of m-nitrobenzoic acid (mNBA) in sulfuric acid were investigated with cyclic voltammetry.The results showed that the most suitable electrode material was copper.The peak current of mNBA reduction increased with increasing scan rate and temperature.The electrode process was controlled by diffusion, and was accompanied by irreversible chemical reaction.The additive SnCl2 showed good electro-catalytic activity for the electrochemical reduction of mNBA.