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Table of Content
05 December 2010, Volume 61 Issue 12
    Electrocatalytic oxidation of glucose at Ti/nanoTiO2-ZrO2 electrode
    FANG Wenyan, WANG Fengwu, XU Mai, ZHU Chuangao, WEI Yijun, ZHU Qiyong
    2010, 61(12):  29-32. 
    Abstract ( 626 )   PDF (599KB) ( 155 )  
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    The precursor TiOCH2CH34-yacacy was synthesized by electrolysis of titanium and in absolute ethanol and acetyl-acetone solution.0.5 g ZrCl4 was added into the above.Nano-crystalline TiO2-ZrO2 powder was prepared by directs sol-gel method from the precursor and then calcined for 2 h at 400. XRD and TEM results showed that the nano-TiO2-ZrO2 of 3040 nm was obtained.The highly active Ti/nanoTiO2-ZrO2 modified electrode was prepared by using daubing and drying.The results of cyclic voltammetry showed that Ti/nanoTiO2-ZrO2 modified electrode as anode exhibited high electrocatalytic activity for electro-oxidation of glucose.

    综述与专论
    Applications of ionic liquids in heat transfer and heat storage process
    BAI Liguang;ZHU Jiqin;CHEN Biaohua;LI Chengyue;FEI Weiyang
    2010, 61(12):  3037-3043. 
    Abstract ( 1020 )   PDF (480KB) ( 576 )  
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    Comparing with the traditional thermal storage and heat transfer materials, ionic liquids have an equal or better performance, such as low vapor pressure, high heat storage density, high physical and chemical stability, high thermal conductivity, low melting point, designable and so on.Therefore, the ionic liquids are of great potential for the application in solar energy collection, building energy conservation, electric power control, low-grade waste heat storage, adsorption heat pump and other areas.This paper summarized the application of ionic liquids in heat transfer and heat storage, including heat transfer fluids in the solar collectors as the absorption medium in cooling(heating), as well as the phase change materials in heat storage.In addition, this article also pointed out that some properties, such as corrosive, toxic, etc.will be focused when these ionic liquids used in the process of thermal storage and heat transfer.

    Research progress of reaction path synthesis methodology of chemical processes
    JIAO Wei;LIU Qian;XIANG Shuguang
    2010, 61(12):  3044-3050. 
    Abstract ( 1142 )   PDF (867KB) ( 408 )  
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    As the focus of process synthesis, reaction path synthesis plays a key role in reducing environmental impact of processes and improving process safety.In this paper, the current status of research in reaction path synthesis is reviewed, especially the synthesis techniques involving environment and safety.The implementation process of such techniques is presented, and their advantages and disadvantages are analyzed.Several important reaction path synthesis methods are evaluated.Three areas of future research on reaction path synthesis are proposed as follows.To achieve inherent safety of reaction path by integrating strategies with inherent safety, based on existing reaction path synthesis methods.To obtain multi-objective optimal solution of reaction path by applying multi-objective optimization methods.To integrate reaction paths with minimum impact on environment from the global perspective of processes system, application research and realization of reaction path synthesis focusing on minimizing environmental impact is of great practical significance.

    Research progress of fractals in vascular networks
    LV Yonggang;YANG Li
    2010, 61(12):  3051-3058. 
    Abstract ( 954 )   PDF (1450KB) ( 839 )  
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    The significance, theories and experimental techniques of fractal topics in vascular networks are comprehensively reviewed, particularly for the latest progresses in the application of fractal theory in vascular network geometrical structure, angiogenesis, and vascular pathology.The effect of vascular network geometrical structure on mass transport in tumor blood vessels is analyzed.Some recent new phenomena as well as new approaches and directions are also summarized.

    热力学
    QSPR study on thermodynamic properties of polybrominated dibenzofurans and polybrominated dibenzothiophenes
    DU Xihua
    2010, 61(12):  3059-3066. 
    Abstract ( 1047 )   PDF (527KB) ( 585 )  
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    Polybrominated dibenzofurans (PBDFs)are important toxic organic contaminants released from the combustion and Pintsch process of brominated flame retardants.The properties of PBDFs are related to their structures.The structure of polybrominated dibenzothiophenes (PBDTs)is similar to that of PBDFs.In this study, atomic characteristic values of 254 molecular structural patterns of PBDEs and PBDTs are calculated, and a new connectivity index, the path index, is obtained by applying the technique of molecule graphics.The path index is combined with five thermodynamic properties of PBDFs, including molecular total energy (ET), standard enthalpy (H0), free energy (G0), standard entropy (S0)and heat capacity at constant volume (c0v), along with four thermodynamic properties of PBDTs, including standard enthalpy (H0), free energy (G0), standard enthalpy of formation (ΔfH0)and standard free energy of formation (ΔfG0.Nine quantitative structure-property relationship models (r2>0.995)are obtained by multiple linear regression method.The Jackknifed cross validation is used to test the stability and prediction ability of each model and good results (r2>0.995)are obtained.The relative mean deviation is 0.52% to S0.The model developed is in good agreement with the values of S0 in literature.

    Prediction on lower flammability limit temperature of organic compounds based on GA-BP neural network
    DU Jianke
    2010, 61(12):  3067-3071. 
    Abstract ( 884 )   PDF (1252KB) ( 600 )  
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    A genetic algorithm-based BP neural network method is constructed to predict the lower flammability limit temperature(LFLT) of organic compounds.The parameters in the model are molecular descriptors of Mv, CID, EEig02d, GGI1, nROH, nHDon.They are selected from 1664 molecular-based parameters obtained from Dragon software.For 1171 organic compounds used in this work, the average relative error and the average absolute error of this model are 3.23% and 10.28 K respectively.The correlation coefficient is 0.9833.The results are better than those obtained by genetic algorithm multiple linear regression(GA-MLR) analysis.The present model can be used to reveal the quantitative relation between LFLT and molecular structures of organic compounds and predict the LFLT of a wide range of organic compounds.

    流体力学与传递现象
    Influence of heat transfer inside particles on coal pyrolysis at ultra-high temperature
    SHUANG Yue;WU Changning;YAN Binhang;CHENG Yi
    2010, 61(12):  3072-3079. 
    Abstract ( 919 )   PDF (1925KB) ( 348 )  
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    Coal pyrolysis in thermal plasma opens up a direct means for producing acetylene.This process is operated under ultra-high temperature conditions with the reaction time in milliseconds, where the rapid heating of coal particles and the release of volatile matters from coal particles play the dominant role in the overall reactor performance.A mechanism model was proposed for a deep understanding of the heat transport inside a coal particle under extreme environmental conditions, which incorporated the heat conduction in solid materials and heat resistance due to the outward diffusion of released volatile gases.The predicted yield of volatiles considering the heat transfer inside the particle agreed reasonably with the reported experimental data under different operating conditions, indicating 30%40% time delay compared with the case without consideration of the heat resistance inside a particle.This effect became more evident for larger particles.Meanwhile, the heating fluid at a higher temperature could speed up and intensify the devolatilization of coal particles.Limited to the milliseconds process of coal pyrolysis, particle size greater than 100 μm or the heating fluid temperature lower than 2000 K is not recommended in the practical application because of the slow release of volatiles in coals.

    Influence of heat flux on forced convective heat transfer in duct with micro-cylinder-group
    ZHANG Chengwu; LIU Zhigang;GUAN Ning
    2010, 61(12):  3080-3085. 
    Abstract ( 1058 )   PDF (1031KB) ( 321 )  
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    Deionized water, used as working fluid, flows through a staggered array micro-cylinders-group with 3.5 mm width and 40 mm length, which are made of micro-cylinders with hydraulic diameter of 500 μm and heights of 500 μm, 750 μm and 1000 μm.An experimental study is performed on the influence of heat flux on forced convective heat transfer in the micro-cylinders-group heated by an electricity heater.The flow rate and the temperature difference between the inlet and the outlet of micro-cylinder-group are measured and the Nusselt numbers are obtained over Reynolds numbers ranging from 100 to 1000.The experimental results indicate that heat flux has a significant effect on the convective heat transfer in the micro-cylinders-group.As the heat flux increases, the average temperature of the working fluid increases apparently, which decreases the Prandtl number, so that the convective heat transfer of the working fluid is weakened.On the other hand, the viscosity of the working fluid is lower at higher heat flux, which intensifies the molecular thermal motion and strengthens the flow disturbance, enhancing the heat transfer.As the heat flux increases at low Re, the adverse effects of the end-wall effect on convective heat transfer is weakened, and the temperature difference between the wall and the working fluid is increased, further enhancing the heat transfer.With the increase of Re, the influence of heat flux increment on the convective heat transfer decreases due to the weakness of end-wall effect.

    Effect of system pressure on spray cooling heat transfer and surface temperature uniformity
    CHENG Wenlong; HAN Fengyun;LIU Qinie;FAN Hanlin
    2010, 61(12):  3086-3091. 
    Abstract ( 920 )   PDF (1433KB) ( 519 )  
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    Spray cooling is a new type of high heat flux heat transfer.The spray cooling in a closed loop was investigated by the experimental method, in which distilled water was used as the working fluid.The heat transfer characteristics including the spray cooling curve, the temperature non-uniformity on the cooled surface, and the corresponding non-dimensional correlation were obtained by experimental analyses.The experimental results show that: the spray cooling heat transfer in the low system pressure is stronger than that in the normal system pressure, because the spray cooling curves are almost in the two-phase region under the low system pressure.The heat flux curve shows an exponential growth with the decrease of the system pressure in the spray chamber.For the average surface temperature of 85, the heat flux reached 360 W·cm-2.The surface temperature non-uniformity on the cooled surface in the low system pressure is lower than that in the normal system pressure.

    Thermal and hydrodynamic performance of high humidity gas convection-condensation in a tube with edgefold-twisted-tape
    CUI Yongzhang, TIAN Maocheng
    2010, 61(12):  3092-3099. 
    Abstract ( 1148 )   PDF (1911KB) ( 589 )  
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    Thermal and hydrodynamic performance of high humidity gas convection-condensation in a tube with edgefold-twisted-tape inserts was investigated experimentally, in which the main experimental parameters are wall temperature, vapor content, velocity and inlet temperature of the mixture.It is found that decreasing wall temperature and increasing vapor content enhance both convection and condensation, especially for vapor condensation.Structure parameters, such as the twist ratio and clearance between tube and tape, may change the condition of condensation film in the tube.The results show that higher twist ratio leads to higher swirl flow intensity and thicker condensation film, which decrease the heat transfer and increase the pressure drop.When the clearance between tube and tape is small, the condensation film may remain at the tip of tape and prevent the gas flowing through.When the clearance is large, the gas can flow through the tip of tape easily and the thickness of condensation film is small, so that the heat transfer is intensified.

    Fluid dynamics in laboratory U-shaped fluidized bed
    HU Jinghui, DONG Li, WANG Yin, LIU Xinhua, XU Guangwen
    2010, 61(12):  3100-3106. 
    Abstract ( 946 )   PDF (2002KB) ( 359 )  
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    A fluidized bed was partitioned internally into two compartments which are interconnected through a passage inside the bed.The particles, which represent a kind of solid feedstock, are fed into one of the compartments and flow out the bed from the other compartment, resulting in a U-shaped pathway of the particle flow.This kind of bed is thus called the U-shaped fluidized bed(UFB), and is suitable for conducting the decoupling gasification of biomass with high water contents.The fluid dynamics of the quartz sand fluidized by air in a laboratory cold UFB  were investigated via both experiment and the FLUENT modeling.The FLUENT modeling revealed that it was necessary to install a perforated plate into the compartment from which particles flow out for achieving the expected uniform distribution of gas entering this compartment from the other compartment.The cold model test results verified this point and demonstrated that the UFB required a range of fluidizing gas velocities for ensuring the normal operations of the UFB.The pressure balance between the two compartments of the bed was found to be the factor controlling the particle fluidization and gas distribution in the UFB.Analyzing the particle residence time in the UFB clarified further that the residence time distribution was very close to the predicted profile via the CSTR model.

    Ethylene polymerization with TiCl4 immobilized on inorganic/organic hybrid support SiO2/MgCl2·xBu(OH)2/PSA
    DU Lijun, JIANG Binbo, WANG Jingdai, YANG Yongrong, LIAO Zuwei, WU Wenqing
    2010, 61(12):  3107-3116. 
    Abstract ( 1120 )   PDF (3186KB) ( 132 )  
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    SiO2/MgCl2·xBu(OH)2/poly(styrene-co-acrylic acid) inorganic/organic hybrid support was synthesized and was of three types of chemical environments: inorganic support SiO2, MgCl2·xBu(OH)2  adduct and organic support PSA.TiCl4 was immobilized on the hybrid support.The influences of its composition on the titanium content, catalyst morphology and performance in ethylene polymerizations were also investigated.The results showed that titanium content decreased sharply when PSA was added to the hybrid support.The kinetic study of ethylene/1-hexene copolymerization indicated that there was a long period of diffusion-controlled induction time at the initial stage for the hybrid catalysts, due to the barrier effect from PSA, comparing with SiO2/MgCl2·xBu(OH)2/TiCl4 that had no induction time in ethylene polymerization. As the content of PSA increased, the induction time extended and almost no decay happened until the end of the polymerization.Moreover, the polyethylene produced by SiO2/MgCl2·xBu(OH)2/PSA/TiCl4 was of broader molecular weight distribution(MWD) and high melt flow ratio. Based on its morphological features showed by SEM, the polymerization mechanism of the hybrid catalysts was also investigated.

    催化、动力学与反应器
    Synthesis and characterization of 1,3-disubstituted imidazol(in)ium-2-carboxylates
    WANG Yanqin;LI Zhenjiang
    2010, 61(12):  3117-3123. 
    Abstract ( 929 )   PDF (1007KB) ( 388 )  
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    The air- and water-stable 1,3-disubstituted imidazol(in)ium-2-carboxylates(NHCCO2) as important precursors of N-heterocyclic carbenes were prepared by three routes.Nine kinds of  NHCCO2 with different groups on nitrogen atoms were obtained.The structure was characterized by 1H NMR, elemental analysis and IR.Thermogravimetric analysis(TG/DTG) provided the evidence for decarboxylation in NHCCO2.The results show that CO2  escapes from the molecule in the process of elevating temperature and free carbenes are released.Two processes(decarboxylation and decomposition) occur when the substituents on the nitrogen atoms are aryl group, and the imidazolium-2-carboxylates and the imidazolinium-2-carboxylates show similar performance of decarboxylation.The initial temperatures of mass loss are lower when the substituents on the nitrogen atoms are alkyl group, and no decomposition occurs.

    Kinetics for extraction of boric acid from salt lake brine by 2-ethyl hexanol-toluene
    LV Jianhua LI Chunli, GENG Hui
    2010, 61(12):  3124-3129. 
    Abstract ( 1062 )   PDF (598KB) ( 397 )  
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    The kinetics of extracting boric acid from salt lake brine were investigated on the conditions of different initial concentrations of boric acid and 2-ethyl hexanol, temperature and the interfacial area of two-phase.The method of rising drop technique was used in the experiment with 2-ethyl hexanol as the complexing agent and toluene as a diluent.The result shows that the extraction rate of boric acid increases with the increasing of the initial concentrations of boric acid in the aqueous phase and 2-ethyl hexanol in the organic phase, the interfacial area of two-phase.The extraction reaction between boric acid and 2-ethyl hexanol is the quick reaction, which occurred in the interfacial area of two-phase.The extraction process is the diffusion-controlled mode by the calculation of the apparent activation energy.The kinetics equation of extracting boric acid with 2-ethyl hexanol regressed from the experimental data with the linear least square method can be expressed at pH=1(aqueous phase) and 318.15 K, and the relative deviation of rate constant is 5.318%.

    Improved synthetic process for 3-benzyloxy-4-n-butylaniline hydrochloride
    DAI Liyan, YUAN Gengyang, YU Yifu, WANG Xiaozhong, CHEN Yingqi
    2010, 61(12):  3130-3134. 
    Abstract ( 1230 )   PDF (518KB) ( 513 )  
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    An improved synthetic process for 3-benzyloxy-4-n-butylaniline hydrochloride the key intermediate of nequinate which is an anticoccidal drug to parasites of Eimeria,was described.The process was started with 3-aminophenol, via acylation, Fries rearrangement, benzylation, hydrolysis, and Huang-Minlon reduction, to give the title compound.The optimal reaction conditions and molar yield were as follows: acylation, 130140 for 3 h; Fries rearrangement, 140 for 5 h, 77.9%(based on 3-aminophenol); benzylation, 70 for 2 h and 80 for 4 h, 81.3%; hydrolysis and Huang-Minlon reduction, reflux for 90 min, 78.2%.The structures of the main compounds were confirmed by 1H NMR. The process is much of industrial value because of high yields, cheap and available materials, moderate reaction conditions and convenient operations.

    分离工程
    Computer aided solvent scanning for separation of diphenyl and 4-phenylacetophenone
    ZHAO Yueqiang, JIANG Xinglong, LIU Weiwei, WU Zhengming, JIA Haihong
    2010, 61(12):  3135-3141. 
    Abstract ( 1180 )   PDF (595KB) ( 600 )  
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    The solvents for the separation of diphenyl and 4-phenylacetophenone were screened with computer according to the solid-liquid equilibrium equation based on UNIFAC.With the predicted separation factor values and selection principle for feasible solvents, the candidates of better solvents were determined as n-heptane, n-hexane, cyclohexane and diisopropyl ether.The solubility and separation factor of the two solid solutes in n-heptane, n-hexane, cyclohexane, diisopropyl ether and ethanol were measured by static equilibrium method.The average relative deviation between the calculated separation factor and experimental data is 16.73%, indicating that the solid-liquid equilibrium equation based on UNIFAC is suitable to select the separation solvent for solid solute mixtures with similar molecule stereoscopic structures.

    Integration of energy power system in CO2 capture by utilization of cold energy from liquefied natural gas
    XIONG Yongqiang, HUA Ben
    2010, 61(12):  3142-3148. 
    Abstract ( 1133 )   PDF (1534KB) ( 391 )  
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    For improving cold energy utilization of liquefied natural gas(LNG) and power generation of CO2 near-zero emission power cycle and reducing energy consumption of CO2 emission reduction, the exergy analysis of LNG cold energy utilization in CO2 near-zero emission power cycle was performed.A natural gas Rankine cycle with integrated CO2 near-zero emission power cycle was proposed.While maintaining the necessary supply of cold energy in pre-cooling and liquefaction of CO2, the deep cryogenic exergy of LNG in CO2 near-zero emission power cycle was converted to power by the natural gas Rankine cycle.The results showed that with the integration of the two above-mentioned power cycles, the exergy efficiency of LNG cold energy utilization could be increased from 34.9% to 55.7%, and the exergy efficiency of the entire integrated power cycle reached 57.9%.Meanwhile, the influences of some parameters of the natural gas Rankine cycle on power generation efficiency were analyzed.

    过程系统工程
    Multi-objective optimization for reactor network synthesis
    YANG GuojunLI XiuxiYANG SiyuQIAN Yu
    2010, 61(12):  3149-3154. 
    Abstract ( 954 )   PDF (880KB) ( 260 )  
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    Reactor network synthesis optimization is an important means to improve the whole economic efficiency and environmental performance in chemical industry.The methods for reactor network synthesis optimization mainly include attainable region approach, derivative analytic approach, approaches based on superstructure optimization, approaches based on targets, empirical deduction method and distributed parameter method.However, there are very few papers on multi-objective optimization for reactor network synthesis.The processes generally have multiple objective functions that are conflicting in nature, so single objective optimization technique is not an appropriate approach.In this study, the multi-objective optimization model was established by using the distributed parameter method with maximizing economic benefits and minimizing environmental impact as objectives, and non-dominated sorting genetic algorithm(NSGA-) was used to obtain a Pareto optimal set.

    Optimization of p-xylene oxidation reaction based on multi-objective evolutionary algorithm
    QI Rongbin, QIAN Feng
    2010, 61(12):  3155-3161. 
    Abstract ( 1061 )   PDF (930KB) ( 242 )  
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    Aiming at the limitation that the single-objective optimizing algorithm is generally easy to trap into local optimal solution, multi-objective evolutionary algorithm based on elitist selection and individual migration was proposed for single-objective optimization problem.Decomposing the original single objective into multi-objectives, it could broaden its searching extension and quicken its converging speed.Simulation results showed that the proposed method could obviously speed up its converging performance.Furthermore, the application to p-xylene oxidation reaction indicated that the proposed method could obviously reduce acetic acid and p-xylene combustion loss, greatly reduce production cost at the same numerical computing cost.

    Structure optimization of heat exchanger network for batch processes based on pseudo-temperature
    DU Jian, LI Chunni, CHEN Li
    2010, 61(12):  3162-3166. 
    Abstract ( 1165 )   PDF (1188KB) ( 644 )  
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    The structure optimization of heat exchanger network for batch processes was studied with the heat exchanger network based on pseudo-temperature.Based on the Time Slice Model, the direct heat exchanger network for batch processes was synthesized by replacing approach temperature with pseudo-temperature, and the thermal load loops could be determined within each time interval of the heat exchanger network.According to specific rules to disconnect loop of the heat exchanger network, structural optimization for the final network was performed to reduce the number of the heat exchanger units and to meet the minimum annual cost.

    Optimal design of batch heat exchanger networks based on self-organizing Petri Net
    JIA Yang, XIAO Wu, DONG Hongguang
    2010, 61(12):  3167-3171. 
    Abstract ( 1086 )   PDF (706KB) ( 245 )  
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    According to the time-dependent heat cascade analysis technique, time places,which represent time for batch process, were imported to the self-organizing Petri Net modules of continual heat exchange network(HEN) to optimize batch HEN. Introducing time places,the representation of time in Petri Net was developed and the research of reachability became easy.Besides, based on the enabling rule of vertical heat transfer, streams split in HEN based on pinch technology were studied and the equations considering comprehensively all the principles of pinch technology were established to split steams accurately and quickly at the pinch point.An example was presented to demonstrate the validity and advantages of the proposed approach.

    Managing financial risk in designing multi-echelon supply chain networks in petrochemical industry
    WANG Jishuai, FENG Yiping, RONG Gang, LIAO Zuwei
    2010, 61(12):  3172-3179. 
    Abstract ( 943 )   PDF (661KB) ( 443 )  
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    The financial risk management in the design of multi-product, multi-echelon supply chain networks in petrochemical industry was discussed.The problem consists of determining the number, location, and capacity of warehouses and distribution centers to be set as well as the transportation links to be established and the flows and production rates in the network.A model dealing with uncertainty and financial risk management constraints was proposed.The model was established in the framework of deterministic two-stage stochastic programming.Based on a supply chain networks design for a petrochemical company, the financial risk was analyzed, and the ability to manage the risk was discussed.

    Modelling and simulation of external loop spray ethoxylation reactor
    LI Jia, AN Weizhong, ZHANG Haibin, ZHOU Liming, ZHU Jianmin
    2010, 61(12):  3180-3185. 
    Abstract ( 1135 )   PDF (984KB) ( 379 )  
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    The modeling and simulation of semi-batch external loop spray ethoxylation reactor was studied.By analyzing the characteristics of the reactor, a mathematical model and numerical algorithm were developed to describe the behavior of the reactor.The model took the vapor-liquid transfer, kinetics, vapor-liquid equilibrium, variation of reactive volume, as well as the effect of inert gas nitrogen on the reactor into account.Based on the developed model, simulations were performed by taking the production of polyethylene glycol as an example.The simulation results provided the typical dynamic profiles of the reactor temperature, pressure, ethylene oxide concentration, as well as the ethoxylated oligomer distributions.Simulation results were compared with the full-scale plant data, which showed the reliability of the developed mathematical model.

    Simulation of distillation unit based on artificial immune network multi-agent algorithm
    SHI Xuhua, QIAN Feng
    2010, 61(12):  3186-3192. 
    Abstract ( 1125 )   PDF (820KB) ( 457 )  
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    In petrochemical field, the process simulation for distillation is an important task.The key parameter in the distillation process simulation is the tray efficiency, which can not be obtained easily.Thus the determination of appropriate tray efficiency is an important issue.In this study, artificial immune network multi-agent optimization strategy(Maopt-aiNet), which combines immune mechanics and multi-agent technology, is used to determine the Murphree efficiency.The main search operators of Maopt-aiNet include neighborhood clonal selection, neighborhood competition, self-confidence motivation, self-confidence neighborhood learning, and neighborhood collaborative operators.Based on the process and analysis data of the distillation unit, Maopt-aiNet is applied to determine the Murphree efficiency for each stage and to minimize the square summation of models analog relative error of the stage temperature.The experimental results show that with the tray efficiency determined by Maopt-aiNet the model fits the actual distillation unit fairly well.The method can be used to guide the operation of the distillation process.

    Numerical analysis of sealing performance of dry gas seal with goose-grooves
    PENG Xudong, HUANG Li, BAI Shaoxian, LI Jiyun, GU Tongsheng
    2010, 61(12):  3193-3199. 
    Abstract ( 1147 )   PDF (1663KB) ( 386 )  
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    In order to improve the sealing performance of a dry gas seal with spiral grooves onto its faces(S-DGS), a new type of dry gas seal with its groove outline between S-DGS and a spiral groove dry gas seal with an annular groove(AS-DGS) was presented.The shape of surface grooves of such a new dry gas seal was similar to that of a flying goose, so it was simply named as GS-DGS.The geometrical parameters of flying goose grooves were defined.A two-dimensional Reynolds equation for controlling film pressure between the two faces of such a GS-DGS was set up according to the theory of gas lubrication.The finite element method was used to solve the Reynolds equation.The variation of opening force, leakage rate, axial film stiffness and ratio of film stiffness to leakage with the geometrical parameters of goose-grooves was studied.Optimization of such geometrical parameters was finished according to the principle of getting small leakage while maintaining high axial film stiffness.The results showed that excellent sealing performance could be obtained for a GS-DGS when the width ratio of groove and land was between 0.8 and 1.2, the radial width ratio of the groove was between 0.4 and 0.8, the goose neck groove length ratio was between 0.25 and 0.35, the goose neck groove width ratio was between 0.2 and 0.4, the groove depth to gas film thickness ratio was between 2.5 and 4.0, the number of grooves was between 10 and 18, and the spiral groove angle was between 10° and 18°.

    Influence of pretreatment on property of electroless plating of Ni-P on aluminum surface
    SUN Hua, MA Hongfang, LIU Kegao, LIU Yi
    2010, 61(12):  3200-3204. 
    Abstract ( 989 )   PDF (2144KB) ( 367 )  
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    Aiming at the disadvantages of aluminum alloy, such as vulnerable to intercrystalline corrosion, low surface hardness, poor abrasion resistance, electroless plating of Ni-P on aluminum surface was studied. The deposition rate, microhardness, bond strength and corrosion resistance were measured with metallographic microscope, SEM energy spectrum analysis, mass-increase method, thermal shock test and grid test, mass-loss method to determine the effect of the parameters of nickel-phosphorus alloy electroless plating process and the time of pre-electroless plating and activation process.The pre-electroless plating process used NiSO4 as main salt, NaH2PO2 as reducing agent and Na4P2O7 as complexing agent.The results showed that the new activation and pre-electroless plating process could significantly improve the bond strength of Ni-P coating and substrate.The highest deposition rate could be achieved.At the same time, the organizational structure of the coatings was dense and uniform, with good hardness, and excellent corrosion resistance.

    Optimization of fermentation conditions in liquid state of Trichoderma viride to produce yellow pigment
    ZHANG Xiaoyi, CUI Yingde, LU Ning, YU Xin, ZHAO Meimei
    2010, 61(12):  3205-3212. 
    Abstract ( 1245 )   PDF (1753KB) ( 516 )  
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    The composition of nutrient medium and the condition of fermentation process were optimized for T.viride producing yellow pigment by three-factor Box-Behnken design and response surface analysis, which was based on the experimental results of single factor for testing bacterial strain Trichoderma viride,including the source of carbon and nitrogen, liquid loading, rotation speed, inoculum concentration, culture time and temperature etc.The results show that the optimum culture medium components and conditions are: liquid culture medium based on PDA(250 g·L-1 potato extract and 2 g·L-1 Na2HPO4), 35, inoculum 6%(vol), carbon source 21.7 g·L-1  xylose, loading liquid amount 50 ml in 250 ml Erlenmeyer flask and culture time 152 h at 120 r·min-1. In the optimal conditions, the color value of yellow pigment obtained is (52.8±0.8)U·ml-1.The formation of yellow pigment would be inhibited by adding urea, ammonium sulfate, peptone, beef extract powder as the source of nitrogen.

    Optimizing expression and purification of recombinant halohydrin dehalogenase from A.radiobacter AD1
    LI Yang, TANG Lixia, ZHENG Kai, WANG Xiong, JIANG Rongxiang
    2010, 61(12):  3213-3219. 
    Abstract ( 1026 )   PDF (1013KB) ( 616 )  
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    Optically pure epoxides and β-substituted alcohols, constituting one of the most important classes of building blocks for the synthesis of chiral drugs, could be obtained via reactions catalyzed by halohydrin dehloagenases.Researches aimed at the improvement of over-expression and purification of recombinant halohydrin dehalogenases will greatly facilitate its application.The encoding gene was successfully cloned into pBAD expression vector.Under the developed optimized expression conditions, halohydrin dehalogenase could be expressed as a soluble format in E.coli using the two expression systems.The soluble targeted protein was about 35% of the total soluble proteins as judged by activity measurements and SDS-PAGE analysis.From 0.5 L cultures of each, 34 mg and 41 mg of 90% pure halohydrin dehalogenase were obtained by using one-step Q-Sepharose anion exchange chromatography, respectively.Meanwhile, the constructed pBADHheC plasmid would set a solid base for improving the biocatalytic properties of the enzyme.

    Change of coal structure during washing process
    SHI Jinming, XIANG Jun, HU Song, SUN Lushi, SU Sheng, XU Chaofen, XU Kai
    2010, 61(12):  3220-3227. 
    Abstract ( 1545 )   PDF (2167KB) ( 590 )  
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    In order to demonstrate the change of coal structure and the effect of mineral, Yangquan anthracite, Northeast lean coal and Xiaolongtan lignite were used in this study, and the samples were prepared by washing with water and acid.Low-temperature ashing and X-ray fluorescence(XRF) were used to analyze the ash compositions, and coal structure was analyzed by Fourier infrared spectrum(FTIR.Introducing infrared parameters provided additional information of the molecular structure of coal which was not reflected by FTIR.It was shown that the effect of water-washing for demineralization was not remarkable, and the main removed minerals were soluble substances, but the main removed minerals during acid-washing were crystalline SiO2.With the increase of coal rank, minerals and coal molecular structure integrated more closely.The lower the coal rank, the more complex the groups in coal structure, but the IR spectrum indicated a regular pattern in high rank coal.The aliphatic degree in lean coal and anthracite were very low and there was aromatic carbon skeleton mainly, but there was a lot of branched-chain structure in lignite.

    Thermogravimetric analysis for direct reduction of iron ore powder by coal
    FAN Lijuan, LV Qinggang, NA Yongjie
    2010, 61(12):  3228-3234. 
    Abstract ( 816 )   PDF (1569KB) ( 634 )  
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    To determine the temperature range of iron ore reduction, the mixture of Datong bituminite and iron ore powder was reduced, and this process was measured by non-isothermal thermogravimetry.Gas product was analyzed by Fourier transform infrared spectroscopy(TG-FTIR) and solid one by X-ray diffraction(XRD.The conversion, reduction fraction of iron ore and phase composition of solid product were calculated quantitatively for each stage.For comparison, the reduction behavior of the iron ore with Datong bituminite, Shenmu lignite or Yangquan anthracite was further studied by the non-isothermal TG technique.The results showed that the mixture of the iron ore and the Datong bituminite exhibited better redox response at relatively low temperatures(800950) than the other two mixtures.At higher temperatures(10001100), the sample of the iron ore and Shenmu lignite also showed good reducibility.

    Mechanism of methane formation during toluene pyrolysis using DFT calculation
    JIA Jianbo, ZENG Fangui, LI Meifen, XIE Kechang
    2010, 61(12):  3235-3242. 
    Abstract ( 1427 )   PDF (1495KB) ( 674 )  
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    The greater part of macromolecule aromatic structure unit of low-rank coal contains mainly 12 rings. In order to understand the mechanism of methane formation during coal pyrolysis, the thermodynamics and kinetics calculation were conducted for toluene pyrolysis using DFT method. The results showed that the rate-control step is the dehydrogenization or demethylation process for all routes of methane formation. The energy barrier of toluene demethylation can be significantly reduced by the participation of hydrogen free radical. When temperature is lower than 675 K, the formation of methane is mainly through the following steps: firstly, breaking of the CH bond in methyl of toluene; secondly, the hydrogen free radical formed adds to the toluene in ipso position and then demethylation; finally, formation of methane is from the formed methyl that captures a hydrogen atom in side chain of toluene. When temperature is higher than 975 K, methane is mainly from toluene demethylation first and then the formed methyl captures a hydrogen atom in side chain of toluene. When the temperature is between 675 K and 975 K,formation of methane is a competitive result of the two routes mentioned above.

    Simulation of direct sulfation of limestone in oxy-fuel combustion
    WANG Xiaofeng, BAI Peng, YAN Zhiqiang, LIU Hao, QIU Jianrong, ZHANG Shengcheng, FENG Qianwei
    2010, 61(12):  3243-3250. 
    Abstract ( 913 )   PDF (643KB) ( 450 )  
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    There exist two reaction modes, direct and indirect, for the gas-solid desulphurization reaction between limestone and SO2 at high CO2 concentration from oxy-fuel combustion.The effect of temperature and SO2 concentration on direct desulphurization was studied with TGA.Based on spherical particle gas diffusion theory, a new method for calculating reaction rate constant and reaction order of SO2 utilizing shrinking unreacted core SUCmodel was proposed.Meanwhile, the method for calculating diffusion coefficient of SO2 through products layer was improved.Furthermore, simulation was carried out using SUC model for the direct desulphurization by limestone at various temperature and SO2 concentration, and the agreement between simulation results and experiment data was good.At last, the effect of temperature, porosity and average pore radius on effectiveness diffusion coefficient are discussed qualitatively based on the model proposed in the paper, and it is found that the effect of temperature is significant but the effects of porosity and average pore radius are comparatively minor.

    能源和环境工程
    Adsorption and catalytic oxidation of Hg0  by semi-wet FGD ash
    WANG Shuai, GAO Jihui, WU Yanyan, WU Shaohua
    2010, 61(12):  3251-3257. 
    Abstract ( 903 )   PDF (1653KB) ( 354 )  
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    Adsorption and catalytic oxidation of Hg0  by NID(novel integrated desulfurization) ash and CFB-FGD(circulating fluidized bed flue gas desulfurization) ash were studied by exposing the adsorbent samples to a simulated flue gas stream in a fixed-bed reactor.The results showed that mercury captured on the surface of desulfurization ash was in Hg2+ form.Higher levels of mercury oxidation were associated with higher levels of mercury capture.Generally, higher levels of mercury oxidation and adsorption rates were achieved by exposing the adsorbent samples in the combination of any two components of Cl2, HCl, NO2  than in a single component.Mercury oxidation and capture rates of NID ash were higher than those of CFB-FGD ash in the same condition.Unburnt carbon and Fe2O3  in desulfurization ash played important roles in mercury adsorption and catalytic oxidation.Mercury oxidation and capture rates increased and then decreased with rising temperature due to the joint action of mass transfer and reaction rate.

    Determination of heavy metals (Pb, Cd, Cr and Hg) in printed paper as food packaging materials and analysis of their sources
    XUE Meigui, WANG Shuangfei, HUANG Chongxing
    2010, 61(12):  3258-3265. 
    Abstract ( 1122 )   PDF (1419KB) ( 449 )  
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    The content of lead, cadmium, chromium and mercury was determined by inductively coupled plasma-mass spectrometryICP-MS in 13 samples of printed paper as food packaging materials and in 3 corresponding non-printed paper samples, which were collected from domestic suppliers, and are 2.0455880.261 μg·L-1, 0.1245.945 μg·L-1, 2.4641430.863 μg·L-1 and 0.17011.378

    Determination of lignin content in black liquor from straw pulp by UV-visible spectrometry method
    BU Lingxi, LU Jie, YANG Ruifeng, YIN Tengfei, ZHOU Jinghui
    2010, 61(12):  3266-3271. 
    Abstract ( 893 )   PDF (1052KB) ( 799 )  
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    A fast, simple and accurate method for determination of lignin content in black liquor from straw pulpBLSPwas proposed, based on an analysis for the typical absorption of 3,5-dinitrosalicylic acid(DNS) as well as black liquor in a fixed UV-visible wavelength region.The analysis indicated that, at wavelength 520 nm, a high linear relationship was found between the contents of lignin dissolved in BLSP and absorbance values of DNS.The interference of glucose and Na2SO3  in black liquor from straw pulp on measuring value could be eliminated.So, this method proposed can be used not only for the accurate determination of lignin content in BLSP but also for lignin content determination in BLSP that produced from basic Na2SO3 process.

    Culture and acclimation of mixed bacteria for industrial hypersaline wastewater treatment
    LIN Hai YU XinleiDONG Yingbo
    2010, 61(12):  3272-3278. 
    Abstract ( 827 )   PDF (990KB) ( 337 )  
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    The culture and acclimation of mixed bacteria were studied systematically, including refractory and salt-tolerant acclimation, for hypersaline polluted water from chemical factories which is degradated hardly.The results show that during refractory acclimation, if CODCr removal rate is as a primary factor, asynchronous domestication should be selected because of its CODCr removal rate 72.0%, much higher than that of synchro one.If reagent cost is as a leading factor, the method of rising CODCr load is the best choice, whose agentia cost is only 5.78 CNY·(t water-1.The method of high CODCr load is characterized by the shortest domestication time of 17 d.Concentration of sodium chloride increases from 50 g·L-1 to 60 g·L-1 by 2 g·L-1, the mixed bacteria adapted hypersaline condition of 60 g·L-1 NaCl after domestication of 20 d, and CODCr removal rate increases slightly, by about 1%.The change of bacteria morphology before and after acclimation, observed by SEM, indicates that the mixed bacteria before domestication is uniform size and surface smooth, and mainly consists of cocci and short bacilli; while that after acclimation is surface rough, mainly consists of long bacilli and contains a lot of secretion, which is a result of acclimatizing themselves to hypersaline environment.

    Treatment technology and efficiency of water works for coping with pollution of phthalate esters in raw water
    LIN Mingli, CUI Fuyi, ZHAO Zhiwei, NIU Chang
    2010, 61(12):  3279-3289. 
    Abstract ( 832 )   PDF (1453KB) ( 436 )  
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    The pollution of phthalate esters(PAEs) in water source of cities is a threat for the safety of drinking water quality.PAEs pollution in the domestic surface water(including water source) and the treated water in water works were reviewed.A combination method of adsorption by powdered activated carbon(PAC) and coagulation-sedimentation was proposed, which can be a suitable technology and coping measure to PAEs pollution in raw water for most water plants in China.Then the removal efficiency of di(2-ethylhexyl) phthalate(DEHP) by the combination technology was experimentally studied.The results show that the technology can remove DEHP effectively in water.The turbidity of treated water is an important influencing factor for the removal of DEHP.The effect of PACs physical and chemical properties on the removal of DEHP from raw water is small.The recommended dose of PAC in the combination technology was given based on the lab experimental results obtained at different pollution levels of DEHP, which can be a technical reference for practice.

    材料科学与工程
    Preparation and characterization of α-Al2O3 submicron powders synthesized at low temperature by sol-gel method
    WANG ShifengWANG HuanpingZHOU GuangmiaoLI DenghaoZHANG BinXU Shiqing
    2010, 61(12):  3290-3295. 
    Abstract ( 898 )   PDF (1231KB) ( 66 )  
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    Using Al(NO3)3·9H2O, Cu(NO3)2·3H2O and Ti(OC4H9)4 as raw materials, Al2O3 submicron powders were synthesized at a low temperature by the sol-gel process, and the phase and microstructure of powders were investigated.By doping Cu(NO3)2·3H2O and Ti(OC4H9)4 into alumina sol, a blue gel was obtained through placing the sol at 80 for a long time.Calcining the blue gel at 950 for 2 h produced amorphous Al2O3 powder with only a little γ-Al2O3 crystal phase, while α-Al2O3 nanopowders with a diameter of 80100 nm were formed at the calcining temperature of 1000.As the calcining temperature increased to 1050, the grains grew to 200400 nm.These results indicated that the synthesis temperature of α材料化学工程与纳米技术

    Preparation and growth mechanism of mono-disperse spherical SiO2 powder
    SHEN Xiaoyi, ZHAI Yuchun
    2010, 61(12):  3296-3301. 
    Abstract ( 1142 )   PDF (2421KB) ( 381 )  
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    With Si(OC2H5)4 as raw material, ultrafine SiO2 powder was prepared by the alkoxide-hydrolysis method under ultrasonic irradiation.XRD, SEM, FT-IR and DTA were used to characterize the phase, micro-morphology, functional group structure and thermal stability of SiO2 powder.The results indicated that the regular mono-disperse ultrafine spherical SiO2 particles were amorphous with uniform size and narrow size distribution.There existed much hydroxyl in SiO2 powder, which could be eliminated by calcining.The crystal form began to transform to cristobalite at 1150, and transformation was completed at 1200.The growth mechanism of SiO2 particle was also discussed by observing the morphologies of samples at different stages of the preparation process.

    Preparation and humidity-controlling characterization of composite CMC-g-PAM/PAAS porous resin by twice foaming method
    YANG Hailiang, PENG Zhiqin, ZHOU Yang, WANG Ziqiang, ZHAO Feng,CAO Xiaoye, ZHANG Jing, HU Zhiwen
    2010, 61(12):  3302-3308. 
    Abstract ( 815 )   PDF (2394KB) ( 340 )  
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    According to the structural design of porous resin, CMC-g-PAM/PAAS porous resin was prepared by the twice foaming method.The morphology and structure properties of the resin were characterized by thermogravimetry (TG), scanning electron microscopy (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption.Humidity-controlling capability and maximum moisture content of the porous resin were tested under high humidity and low humidity conditions.Humidity-controlling capability was investigated at changing absolute humidity and temperature.The results showed that when aluminum chloride was 2.5%mass of the acrylamide monomer, the porous resin showed a humidity-controlling range of 57.5%62.5%, its maximum moisture content was 122% of its own mass.The porous resin was able to maintain relative humidity in the range of 57.5%62.5% also in the case of changing absolute humidity. The porous resin reached equilibrium humidity in less than 1 h at 40 and in less than 3 h at 10.

    Rheological properties, dispersibility and stability of nano-SiC based aqueous slurry
    GUO Xingzhong, YANG Hui, ZHU Lin, ZHU Xiaoyi, ZHANG Lingjie, SHEN Jianchao
    2010, 61(12):  3309-3314. 
    Abstract ( 940 )   PDF (1428KB) ( 443 )  
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    With nano-SiC as matrix, nano-TiN as reinforcement phase, de-ioned water as dispersion medium, TMAH as dispersant and Y3Al5O12(YAG) as additive, nano-SiC based aqueous slurries were prepared, and the effects of solid phase content and dispersant content on rheological properties, dispersibility and stability of the slurries were analyzed.The results showed that shear viscosity and shear stress of aqueous SiC based slurries increased with the increase of solid phase content, and decreased with the increase of TMAH content. The dispersibility and stability of the slurries both increased with the increase of solid phase content and TMAH content.The aqueous SiC based slurry was pseudo-plastic non-Newtonian fluid with shear-thinning property.The nanoparticles in the slurry were parceled or fixed by YAG sol with network structure to form approximate aggregate with the size of 50100 nm, which resulted in the stability and dispersion of nanoparticles.