Please wait a minute...
Table of Content
25 January 2006, Volume 57 Issue 1
    传递现象
    Permeation behaviors consistency in polymeric homogenous dense membranes
    WANG Baoguo;MA Minglin
    2006, 57(1):  1-5. 
    Abstract ( 731 )   PDF (569KB) ( 319 )  
    Related Articles | Metrics
    Pervaporation(PV) or vapor permeation(VP) process was proved to be effective for removing the pollutant from industrial emission, dehydrating organic solvent and separating organic/organic mixtures.Depending on the feed state, researchers generally classify such processes as different membrane separation processes, and engineers design the separation with different method in commercial application. However, both pervaporation and vapor permeation can be analyzed based on the solution-diffusion mechanism, and they ought to possess identical permeation behavior.As a matter of fact, if observation was based on the viewpoint inside a polymer matrix, diffusion behavior of molecules in both operations would take on the identical nature.In order to obtain direct experimental evidence, a specifically designed equipment was developed.A stainless steel cylinder was connected with PV and VP membrane cells on both ends, and half of tank was filled with permeation feed. The feed in this tank showed vapor-liquid equilibrium, nitrogen sweep gas was introduced into the permeation side to remove the permeate on time. Therefore, pervaporation and vapor permeation processes were carried out in one tank simultaneously. This study used ethanol and 2-propanol aqueous, PVA/PAN composite membrane was used to measure individual component permeation behavior in PV and VP,and the results were analyzed based on the thermodynamic equilibrium theory. This investigation showed that water, ethanol and 2-propanol had the almost same permeation rate in both PV and VP process.The experimental results gave a direct evidence for the permeation behaviors consistency in a polymeric homogenous dense membrane.

    Prediction of diffusion coefficients in polymer-solvent systems

    LV Hongling;WANG Baoguo
    2006, 57(1):  6-12. 
    Abstract ( 676 )   PDF (591KB) ( 772 )  
    Related Articles | Metrics
    Solvent diffusion phenomenon in polymeric materials widely exists in both daily life and industrial processes,thus it is of universal significance to study on it.Vrentas and Duda proposed a model based on the free-volume theory to predict diffusion coefficients of low molecular weight solvent in polymeric materials.All parameters in the model were determined by solvent and polymer molecule properties respectively, without any direct diffusivity measurement.Using the Vrentas-Duda model, solvent diffusion coefficients in typical polymer/solvent systems were predicted and compared with experimental data for evaluating availability of the model. For most amorphous rubbery polymeric material systems,the Vrentas-Duda model gave satisfying accuracy for calculating solvent diffusion coefficients, except for the complicated systems with hydrogen bond. This calculation also showed better accuracy for solvent self-diffusion coefficients than mutual-diffusion coefficients.
    Numerical investigation of flow fields in stirred vessels with novel combined inner and outer agitators
    SUN Hui;PAN Jiazhen
    2006, 57(1):  13-20. 
    Abstract ( 791 )   PDF (1269KB) ( 255 )  
    Related Articles | Metrics
    Based on the basic principle of sliding grid method, a new concept of sliding period was proposed and used to simulate the flow fields in stirred vessels with novel combined inner and outer agitators which are rotating in opposite directions.This work was compared with dual pitched paddles and anchor agitator.The velocity fields, mean velocity components, rates of velocity change, shear rates and axial circulation capability were analyzed.The results showed that the use of the concept of sliding period could reduce the CPU time to a certain degree. By using the novel combined inner and outer agitators, the radial and axial flows were strengthened. The combined inner and outer agitators could improve the flow fields near the vessel wall, and work better for pseudo-plastic fluid than Newtonian fluid. In addition, the shear strength and axial circulation capability of combined inner and outer agitators were higher than dual pitched paddles.

    Radiation modeling associated with adaptive chemistry

    QIAO Yu; XU Minghou;Viriato Semiāo;William H. Green
    2006, 57(1):  21-26. 
    Abstract ( 677 )   PDF (7289KB) ( 161 )  
    Related Articles | Metrics
    Most industrial flames are turbulent, exhibit different zones with totally diverse chemistry and have radiation as the dominant heat transfer process. The S4 quadrature version of the discrete ordinates radiation model was applied together with the Adaptive Chemistry (AdapChem) reduced kinetics modeling to a laboratory-scale, axisymmetric, co-flowing partially premixed methane/air laminar flame, previously predicted with success with AdapChem alone,to assess the effects of radiation on the distributions of other variables. Predicted results using the discrete ordinates method, that were compared herein with the experimental values reported in literature and with those predicted with AdapChem alone, showed that temperatures and species concentrations exhibit significant variations when radiation was considered. Nevertheless, the flame topology in terms of reaction structure remained essentially unchanged, although some differences were noticed. The predicted results approached more closely the experimental ones when radiation calculations were included.
    Analysis of energy consumption of EHD enhancement of heat transfer using second law of thermodynamics
    WAN Jinqing;LI Ruiyang;YU Hongling;HUANG Xuan;DONG Wei
    2006, 57(1):  27-30. 
    Abstract ( 682 )   PDF (437KB) ( 203 )  
    Related Articles | Metrics
    Based on the second law of thermodynamics,a method of energy consumption evaluation of electrohydrodynamics(EHD) enhancement of heat transfer was presented, the profit factor of available energy was newly defined.The experimental data were analyzed. The results showed that the profit factor of available energy increased with increasing heat flux under the same voltage given in experiments, while decreased with increasing voltage under the same heat flux given in experiments.It was found for the first time that the application of EHD enhancement of heat transfer was not economical when the voltage was higher than a critical value at a low heat flux. This method provided a theoretical basis for the economy of EHD heat transfer enhancement.
    多相流

    Structural optimization pre-distributor in gas-liquid-solid circulating fluidized bed heat exchanger

    WANG Yiping;LIU Junjie;WU Chenxi;ZHU Li
    2006, 57(1):  31-35. 
    Abstract ( 682 )   PDF (440KB) ( 566 )  
    Related Articles | Metrics
    In this study, two types of pre-distributors (nonuniform-pores and dual-baffle)for the combined solids-liquid distributor in gas-liquid-solid circulating fluidized bed heat exchanger, were designed and the characteristics of particles distribution was compared. In the experiments, the sampling method was used to measure local solids flux and a U shape pipe was used to measure static pressure drop in the lower pipe box.The effects of different superficial liquid velocities and liquid viscosities on the parameters mentioned above were investigated.The degree of distribution of local solids flux in exchanger pipe was evaluated by the non-uniformity function.The results showed that the two types of pre-distributors were both suitable for gas-liquid-solid circulating fluidized bed heat exchanger at a lower static pressure drop in the lower pipe box.Compared with the nonuniform-pores pre-distributor, the dual-baffle pre-distributor showed better performance.
    催化、动力学与反应器
    Simultaneous catalytic removal of soot and NOx over Nd2O3-based complex catalysts
    YUN Xinhua;SHANGGUAN Wenfeng
    2006, 57(1):  36-40. 
    Abstract ( 625 )   PDF (414KB) ( 354 )  
    Related Articles | Metrics
    Simultaneous catalytic removal of soot particulate and NOx in the presence of excess oxygen was investigated over Nd2O3-based metal oxides by using temperature programmed reaction (TPR).The catalytic performance depended significantly on loaded metal oxides, in which the catalyst containing potassium oxide- and manganese oxide-supported neodymium oxide(K/Mn/Nd2O3) was the best catalyst in the study. As a result, the ignition temperature of soot was reduced from 500℃ to 330℃, and the conversion efficiency of NOx to N2 was increased to 75.4%. Potassium oxide promoted obviously the catalytic activities, especially in decreasing the ignition temperature of soot. The amount of potassium oxide had an optimum [2 mmol•(g rare earth oxide)-1], and too much loading of potassium oxide might cause the covering of active sites of the rare earth oxide.
    Performance of new homogenous bimetallic biligand catalyst for NBR hydrogenation
    YUE Dongmei;SHEN Zengmin;XU Ruiqing;WEI Yungkang
    2006, 57(1):  41-45. 
    Abstract ( 532 )   PDF (504KB) ( 265 )  
    Related Articles | Metrics
    A new kind of bimetallic biligand NBR hydrogenation catalyst with two ligands,tetramethylethylenediamine and phenylsulfide, was prepared in this work.The influence of catalyst,reaction temperature, time, pressure, and NBR concentrations on NBR hydrogenation were studied.The results showed higher selectivity, higher activity and lower cost of the catalyst. In addition, the stability of the bimetallic biligand catalyst was checked by a reaction equipment designed for kinetics measurement, and a longer life of this catalyst in air was achieved.The mechanical properties of HNBR product were with the commercial products of Bayer and Zeon.In conclusion, this kind of catalyst was perfect for NBR hydrogenation and of high practical value. In particular, the air stability of this catalyst was better than others.
    Kinetics of enantioselective hydrogenation to synthesize ethyl (R)-2-hydroxy-4-phenylbutyrate
    XIA Tao;REN Qilong;WU Pingdong
    2006, 57(1):  46-51. 
    Abstract ( 589 )   PDF (517KB) ( 154 )  
    Related Articles | Metrics
    The effects of substrate concentration, modifier amount, hydrogen pressure and temperature on initial hydrogenation rate and enantiometric excess were investigated to synthesize ethyl (R)-2-hydroxy-4-phenylbutyrate over Pt/Al2O3 modified by 10,11-dicinchonidine. Based on the proposed mechanism, kinetic models were established for the enantioselective hydrogenation and the parameters were estimated by fitting the experimental data. A rational model, which could describe the reaction well, was determined.

    Decomposition kinetics of fructose catalyzed by organic acids in high temperature liquid water

    LIU Xin;LV Xiuyang;XIA Wenli;REN Qilong
    2006, 57(1):  52-56. 
    Abstract ( 838 )   PDF (419KB) ( 743 )  
    Related Articles | Metrics
    Decomposition kinetics of fructose catalyzed by organic acids in high temperature liquid water was studied at temperatures from 453.15K to 493.15K and pressure of 10 MPa.From the results,it could be seen that the reaction was sped up with organic acids added.Under the same concentration of organic acids, formic acid demonstrated stronger ability to accelerate fructose decomposition than acetic acid.The effects of temperature, organic acids and residence time on the yields of 5-hydromethylfurfural (5-HMF) and levulinic acid(LA) were investigated.Fructose decomposition consisted of two successive reactions, first from fructose to 5-HMF, then from 5-HMF to levulinic acid.From the products profile, it could be concluded that acetic acid sped up the fist step, but had little influence on the second step while both steps were sped up by formic acid.
    Kinetics of pinacol rearrangement in high temperature liquid water
    GAO Fei;LV Xiuyang
    2006, 57(1):  57-60. 
    Abstract ( 651 )   PDF (782KB) ( 369 )  
    Related Articles | Metrics
    The kinetics of non-catalyzed pinacol rearrangement in high temperature liquid water was investigated at 10 MPa and temperature from 180℃ to 220℃. Rate constants were evaluated with the first-order reaction assumption. The activation energy evaluated was 176.4 kJ•mol-1. The experimental results demonstrate that non-catalyzed pinacol rearrangement in high temperature liquid water is possible with high pinacol conversion and pinacolone yield over 80%.
    分离工程

    Influence of support layer of composite PDMS membranes on performance of hydrophobic pervaporation

    LI Lei;TAN Shujuan;JIANG Donghua;WU Fawen;XU Zhihong;ZHANG Zhibing
    2006, 57(1):  61-65. 
    Abstract ( 718 )   PDF (433KB) ( 450 )  
    Related Articles | Metrics
    Three types of composite PDMS membranes were prepared by using PAN, CA, and PVDF as support materials and used to separate ethanol from aqueous solution by pervaporation.The experimental results evidently demonstrated that the support layer had a significant impact on the flux and selectivity of composite PDMS membranes. The effect of the average pore size of supports on the performance of composite PDMS membranes was complex, and depended on many factors such as the physico-chemical properties of skin layers or supports and the preparation methods of composite membranes. The total flux of ethanol-water mixture through each composite PDMS membrane increased with increasing temperature. In contrast, the relation between selectivity and temperature was different due to various supports. With increasing feed concentration, the flux through each composite PDMS membrane increased quickly while the selectivity decreased.All these observation would be helpful to provide a guideline for the selection of an optimum support layer.
    表面与界面工程
    Different analytical methods to determine rhodium in plating solution
    XIAO Yaokun;ZHANG Feng;LIU Zhenhua;CHEN Zongzhang;WANG Xuhui;YU Gang
    2006, 57(1):  66-70. 
    Abstract ( 816 )   PDF (465KB) ( 695 )  
    Related Articles | Metrics
    Several analytical methods to dertermine rhodium such as gravimetric method, inductively coupled plasma spectrometry (ICP), flame atomic absorption spectrometry (FAAS) and FAAS improved (FAASI) by a calibration constant K were studied in this paper. The results showed that for pure rhodium plating solution, gravimetric method was an accurate method to determine rhodium with relative deviation less than 4%, and especially, the deviation was only within 0.2% with alkaline sodium borohydride as reducing agent. For highly contaminated rhodium solution, ICP and FAASI were very good choice and the relative deviation was less than 1%.
    Change of operating voltages in electrosynthesis process of chromic anhydride
    LI Chengwei, YU Zhihui, QI Tao, WANG Fu’an, ZHANG Yi
    2006, 57(1):  71-73. 
    Abstract ( 627 )   PDF (354KB) ( 166 )  
    Related Articles | Metrics
    A new green technology of producing chromic anhydride with an electrochemical synthesis method was studied to solve the pollution problems in the traditional production process of chromic anhydride.A self-made electrosynthesis reactor of pure titanium and stainless steel, with a multiple-unit metal oxides combination anode, a cathode of stainless steel, and a reinforced combination cation exchange membrane with perfluorosulfonic and perfluorocarboxylic polymers was used to carry out, the direct electrochemical synthesis experiment of chromic anhydride from sodium dichromate.From the experimental results and the principle of electrochemical reaction, it was found that the process of electrochemical synthesis reaction of chromic anhydride might be quantitatively followed by the variation of operating voltage measured macroscopically with reaction time. Operating voltages were experimentally measured at the different initial sodium dichromate concentrations of the anolyte in the electrosynthesis process of chromic anhydride, and the variation of operating voltage with reaction time was discussed. The mathematical model of the variation of operating voltages with reaction time and the rate of change equations of operating voltage were established.The model characterizes the change of operating voltages in the electrosynthesis process of chromic anhydride, and provideds the foundations for the further study and process monitoring of the electrochemical synthesis of chromic anhydride.
    生物化学工程、制药、食品和天然产物加工

    Effect of soluble alcohols on conformational changes and refolding of lysozyme

    WANG Wei;BAI Shu;DONG Xiaoyan;SUN Yan
    2006, 57(1):  74-78. 
    Abstract ( 694 )   PDF (870KB) ( 340 )  
    Related Articles | Metrics
    The effects of alcohols on the intermolecular interactions of lysozyme and the conformational changes and refolding pathway of denatured lysozyme were studied by using laser light scattering, circular dichroism spectroscopy and activity assay. The results indicated the presence of strong intermolecular repulsion or weak attraction between lysozyme molecules at low alcohol concentrations.The conformational changes induced in the presence of alcohol did not promote folding to its native structure. At low concentrations of alcohols such as 20% glycerol, 30% glycol and 10% methanol, the denatured lysozyme could be refolded with high activity yields.

    Effect of salt type and concentration on effective pore diffusion coefficient in protein hydrophobic adsorption

    LIU Jianhua;SHI Qinghong;CHEN Jie;SUN Yan
    2006, 57(1):  79-84. 
    Abstract ( 809 )   PDF (432KB) ( 537 )  
    Related Articles | Metrics
    The adsorption equilibria and kinetics of bovine serum albumin (BSA) on two hydrophobic adsorbents, Phenyl Sepharose FF low sub and Phenyl Sepharose FF high sub were investigated in the presence of different salt types and salt concentrations. The results indicated that an increasing salt concentration led to an enhanced adsorption capacity and a decreased dissociation constant, in particular in the salt system of sodium sulfate. Then, the effective pore diffusivity of BSA was predicted by fitting the pore diffusion model to the dynamic batch adsorption data. The results showed that effective pore diffusion coefficient increased with increasing salt concentration as well as ligand density.It was considered due to the enhanced contribution of surface diffusion to the interior mass transfer at high salt concentration and ligand density because of enhanced adsorption capacity under such conditions.

    Preparation and characterization of chitosan/terpolymer microcapsule

    ZHU Jianhang;ZHANG Bao;YAN Xiluan;LAO Xuejun;YU Hanry

    2006, 57(1):  85-90. 
    Abstract ( 692 )   PDF (1075KB) ( 511 )  
    Related Articles | Metrics
    Half N-acetylated chitosan (HNC)-based microcapsules were prepared under neutral conditions by coacervating with methacrylic acid (MAA) (20.4%)-hydroxyethyl methacrylate (HEMA) (27.4%)-methyl methacrylate (MMA) (52.2%) terpolymer (MAA-HEMA-MMA). The formed microcapsules consisted of a liquid inner core of HNC and an outer complexation shell derived from HNC and terpolymer. Prepared from 15.3% N-acetylated chitosans (FNC), HNC maintained good solubility and supplied enough protonated amino groups to coacervate with terpolymer to form microcapsules under physiological conditions. The viscosity of HNC solution between 80 and 3000 cPa•s guaranteed the formed microcapsules with good spherical shape. The preparation parameters, including pH, HNC molar mass, chitosan concentration and reaction time, greatly influenced the intrinsic coating membrane features such as morphology, thickness and network porosity, and further determined microcapsules’ permeability and mechanical stability. Low concentration of HNC favored the permeability of microcapsules, whereas high concentration was good for the resistance of microcapsules to shear force.

    Application of anti-pollution nano-pesticide preparation for chlorfenapyr

    YAN Jianhui; HUANG Kelong;WANG Yuelong; LIU Suqin
    2006, 57(1):  91-96. 
    Abstract ( 690 )   PDF (568KB) ( 700 )  
    Related Articles | Metrics
    Ag/TiO2 was modified by stearic acid to change its surface from hydrophilic to hydrophobic.Chlorfenapyr pesticide,modified Ag/TiO2 and corresponding additives were mixed to fabricate a nano-pesticide formulation. The particles had uniform size, and the mean diameter was about 100 nm. The photodegradation experiment of chlorfenapyr nano-pesticide formulation proved that the preparation was stable in darkness, while the decomposition rate was 15.8% with in lighted room after l5 days, and 69.0% with irradiation under sunlight after 3 days.With irradialtion by UV-light for 22.5 h, the decomposition rate of nano-formulation was more than 9.2 times that of normal formulation. The indoor and field virulence experiments of chlorfenapyr nano-pesticide formulation indicated that nano-formulation had stronger virulence than normal formulation.The LC50 was 8.95 mg•L-1, more than 1.77 times that of EC virulence. Under the condition of half pesticide dosage in the comparative experiment of pesticide protection, the effect of preventing from cabbage Spodoptera litura F. was better than chlorfenapyr EC.
    After using pesticide 1 day and 3 days,corrected protection effect of pesticide was higher by 4.89% and 3.05% respectively.The remnant pesticide experiments of soil and plants indicated that the decomposition of nano-formulation in cabbage and soil was quicker, and the t1/2 was 3.91 and 1.27 days respectively. While the t1/2 of chlorfenapyr SC was 8.64 and 3.27 days respectively.
    能源和环境工程

    Model for design of cathode channels for H2/O2 proton exchange membrane fuel cells

    WANG Hongxing;WANG Yuxin
    2006, 57(1):  97-103. 
    Abstract ( 648 )   PDF (566KB) ( 361 )  
    Related Articles | Metrics
    A theoretical, along-the-channel model, in which momentum transfer,mass transfer and electrode reactions of cathode gases were taken in consideration,was developed to design cathode channels for H2/O2 proton exchange membrane fuel cell. The 2-D problem was converted into 1-D problem, and this was implemented by solving the resultant ordinary differential equation with a straightforward shooting computational scheme. With this design tool, the height and length of the channel can be easily designed. An analysis of the effects of main operation and design parameters on the distributions of concentration, velocity and current density was conducted.
    Biological nitrogen removal from petrochemical wastewater using anoxic and oxic swim-bed reactor
    SHI Lijun, XUN Yuxian, YANG Fenglin, ZHANG Xingwen, WANG Xujiang, KENJI Furukawa
    2006, 57(1):  104-108. 
    Abstract ( 967 )   PDF (994KB) ( 302 )  
    Related Articles | Metrics
    The swim-bed technology is an innovative and highly efficient wastewater treatment process developed by Networking of Engineering and Textile Processing Limited Corporation,Japan.The technology uses a novel biofringe attachment material, which allows for attachment of large amount of biomass on a flexible matrix in a fixed position. By this approach, flexing of the matrix induced by wastewater flow creates a swimming motion, which enhances mass transfer and improves the activity of the biomass. In this paper biological nitrogen removal from petrochemical wastewater was investigated by using an anoxic-oxic swim-bed reactor. The study result showed that good biological nitrogen removal was achieved in the reactor. The influence of mixed liquid recycle ratio and influent load on biological nitrogen removal was discussed. When mixed liquid recycle ratio,influent COD concentration and NH+4-N concentration were 2.5, 400~600 mg•L-1 and 20~40 mg•L-1 respectively,the concentration of COD, NH+4-N and TN in the outlet were lower than 40 mg•L-1, 1.0 mg•L-1 and 7.0 mg•L-1 respectively, and COD removal efficiency, nitrification rate and denitrification rate were 90%, 95% and 70% respectively.
    Chemical structure of C in carbon blacks from pyrolysis of used tires in pilot-scale rotary kiln
    YAN Jianhua, YAN Dahai, CHI Yong, XU Wensheng, NI Mingjiang, CEN Kefa
    2006, 57(1):  109-114. 
    Abstract ( 607 )   PDF (751KB) ( 483 )  
    Related Articles | Metrics
    The chemical structure of C in pyrolytic carbon black(PCB) from the pyrolysis of used tires in a pilot-scale rotary kiln was analyzed by X-ray photoelectron spectroscopy(XPS).The surface charging and background were corrected and the asymmetrical and symmetrical peaks were fitted by “asymmetrical Gaussian-Lorentzian sum function” and “Gaussian function”, respectively. It was found that when pyrolysis was complete at a temperature above 500℃,the chemical structure of C in the bulk of PCB was similar to commercial carbon black(CCB) N660, but different from the PCB surface layer containing absorbates and deposits.At a higher pyrolysis temperature, the content of graphitic C in the surface layer increased. When pyrolysis was not complete at 450℃,the content of graphitic C in the bulk was low and the surface layer was thinner.The PCB was sieved, and the smaller the PCB particle diameter, the lower the content of graphitic C. The thickness of the PCB surface layer was about 0.2 mm and the chemical structure of C in the bulk of PCB was not affected by the surface layer.
    能源和环境工程

    Three-dimensional modeling and experimental validation of air-breathing PEM fuel cell

    WANG Ying;LI Xiangyi;LEE Wonyong;KE Jian
    2006, 57(1):  115-121. 
    Abstract ( 774 )   PDF (1082KB) ( 274 )  
    Related Articles | Metrics
    The air-breathing proton exchange membrane fuel cells (PEMFCs) are one of the most competitive candidates for future portable-power applications. To predict the performance of air-breathing PEMFCs and promote its commercialization, a three-dimensional mathematical model was developed,including full governing equations for fluid dynamics, electrode kinetics, and water transport in membrane. The model was numerically solved with commercial CFD tool STAR-CD and user-defined subroutine in FORTRAN code using the finite-difference technique. According to the numerical results, the experiment system was designed. The performance of an air-breathing PEMFC and temperature distribution on the surface of diffusion layer was tested. The calculated cell performance curve was in good agreement with experimental results.It was demonstrated that the oxygen mass transfer rate by natural convection played a major role in cell performance and the interaction of velocity, temperature, current density, water concentration. The model could be used as a computer-aided design tool for an air-breathing PEMFC to obtain better cell performance.

    Solubility of annabergite

    YUAN Tiechui;ZHOU Kechao;JIA Yongfeng;G P Demopoulos
    2006, 57(1):  122-125. 
    Abstract ( 827 )   PDF (448KB) ( 320 )  
    Related Articles | Metrics
    The solubility of annabergite is characterized by the concentrations of Ni and As. TCLP tests showed that there was a little poorly crystalline product in the annabergite synthesized by the authors.The long-term solubility tests were conducted to evaluate the stability of resultant product and the results showed that the dissolution of annabergite gradually reached equilibrium after 15 days. The solubility was strongly dependant on the pH of the medium with the concentrations of Ni and As decreasing remarkably with increasing pH.The lowest concentrations were 48 mg•L-1 As and 0.2 mg•L-1 Ni at pH 9.Nickel and arsenic of annabergite dissolved at the same step[n(Ni)∶n(As)=1.5]with the theoretical figure of molecular formula, but the Ni/As molar ratio was much lower than the theoretical figure because of Ni(OH)2 precipitated. The solubility of annabergite was much lower than that of Nishimura et al’s.

    Pyrolysis behavior of oil shale semi-coke

    HAN Xiangxin;JIANG Xiumin;CUI Zhigang;ZHANG Chaoqun
    2006, 57(1):  126-130. 
    Abstract ( 992 )   PDF (395KB) ( 465 )  
    Related Articles | Metrics
    The pyrolysis behavior of oil shale semi-coke was studied with the thermogravimetic analyzer.Retorting temperature of 500—600℃ was recommended after quality of shale oil, content and calorific value of semi-coke and design of circulating fluidized bed were comprehensively considered.Retorting degree influenced the start temperature of mass loss and pyrolysis process at low-temperature stage, but had little effect on pyrolysis at high-temperature stage.Pyrolysis process of fuel semi-coke made at a higher distillation temperature could be seen in that of fuel semi-coke made at a lower distillation temperature. Pyrolysis degree of semi-coke would decrease at the same temperature with heat-up rate increasing.However, pyrolysis process of semi-coke would hardly be affected by heat-up rate after heat-up rate was above 40℃•min-1.Pyrolysis kinetic parameters of semi-coke were calculated with the Coasts method and the results might be referred to in simulation calculation and engineering design.

    Principle of sodium alkali FGD with electrodialysis recycling

    XIE Jianzhi;ZHANG Shuting;ZHAO Xinhua; LU Caixia
    2006, 57(1):  131-135. 
    Abstract ( 701 )   PDF (410KB) ( 355 )  
    Related Articles | Metrics
    Electrodialysis recycling principle of sodium alkali flue gas desulfurization(FGD)was studied with anion-exchange membrane and model deduction.Results show that in the process of sodium alkali FGD with anion-exchange membrane electrodialysis recycling,theoretical and practical sulfur electrodialysis ratio were almost the same and increased with the level of current density.Sulfur electrodialysis ratio could be calculated according to the pH of cathode influent and effluent solution.The model was in good agreement with the experiment results and reflected the electrodialysis effect well.Sulfur electrodialysis ratio should be less than 50% and it would increase quickly at pH=6.0—7.5 and increase slowly at pH<6.0 or pH>7.5.The model had good stability in the stated range of influent solution pH.

    Treatment of polluted surface water by MBR process for drinking water production

    HAO Ailing;CHEN Yongling;GU Ping
    2006, 57(1):  136-139. 
    Abstract ( 626 )   PDF (388KB) ( 296 )  
    Related Articles | Metrics
    In China surface water pollution has made quality drinking water production difficult. The major pollutants in surface water are organic matter measured by CODMn and ammonia nitrogen. To remove these pollutants effectively, membrane bioreactor (MBR) was studied as a substitute for the conventional water treatment process. Powdered activated carbon (PAC) was dosed into the reactor to enhance the treatment efficiency. A pilot scale MBR was operated continuously for 130 days. In this period, 79.1% of CODMn, 85.9% of UV254, 97.9% of UV410, 99.6% of turbidity and 97.4% of NH3-N could be removed, and the total coli-group was not detectable per 100 ml in the treated water. Concerning the accumulation of refractory organics in the reactor, an index Am(organics accumulative factor in the mixed liquor) was proposed. It helps to evaluate the efficiency of biodegradation and PAC adsorption of organic pollutants in the reactor. Moreover,Am appeared to have a negative effect on the removal efficiency of organic pollutants.At the end of the pilot test, three-step cleanings were carried out for the fouled membrane. The flux recovery for each cleaning step was measured, and the composition of the eluted foulants after each chemical cleaning step was analyzed. The results demonstrated that organic pollutants were the major membrane-fouling substances, and chemical cleaning with 0.4% sodium hypochlorite could remove them efficiently.

    Single coal particle combustion characteristics and kinetics study using thermogravimetric method under constant temperature

    KUANG Ge;ZHANG Jiyu
    2006, 57(1):  140-145. 
    Abstract ( 646 )   PDF (721KB) ( 302 )  
    Related Articles | Metrics
    A thermogravimetric method under constant temperature replacing the beginning inert gas with burning air was established in this study for determining the combustion kinetics of single char particle. The combustion process of three types of coals, Fujian Longyan coal, Fujian Yong’an coal and Shandong coal, with diameter of 3.0—4.5 mm, in thermobalance under 900℃ was discussed using the familiar shrinking-core model.While the combustion of single char approached the end, the outside and the ash layer diffusion resistances tend to be zero as the reaction resistance dominated in the total resistance of combustion.Therefore, at this stage the inherent oxidation reaction constant (kR) of the above char samples were estimated by analyzing the total resistance of combustion.The good agreement of combustion reaction rate between data determined in this study and calculated values obtained from reference in the drop tube furnace system, implied that the inherent oxidation reaction constant (kR) determined by the thermogravimetric method under constant temperature was satisfactory and valuable. The gas diffusion through the ash layer of char particle during combustion process was discussed also. At the ash layer thickness half the char radius, the ash layer resistance in the combustion process reached a maximum value, at which the total resistance of combustion,1/K,was less than 25 s•m-1 and would be close to the reaction resistance,1/kC,approaching the end of combustion. So the effects of gas diffusion resistance through ash layer on char combustion process could be ignored during the whole combustion process.
    Fluidized bed gasification of PE plastic in municipal solid waste
    XIAO Gang, CHI Yong, NI Mingjiang, MIAO Qi, ZHU Wenli, JIN Yuqi, CEN Kefa
    2006, 57(1):  146-150. 
    Abstract ( 557 )   PDF (1319KB) ( 275 )  
    Related Articles | Metrics
    In order to develop municipal solid waste(MSW) gasification and melting technology with low emission and high efficiency for developing countries, the optimum conditions of ployethylene plastic gasification were studied.Polyethylene(PE) plastic widely existing in MSW was gasified in a fluidized bed. The study was focused on the characteristics of PE gasification at different excess air ratios(EAR) (0.2—0.8) and temperatures (400—700℃).The highest gasification efficiency reached 72% in the above experiments when temperature was 700℃ and EAR was 0.2,and the low heating value(LHV) of product gas was up to 10000 kJ•m-3, the yield was 3.1 m3•kg-1 and the conversion efficiency of C was 80%. The conversion efficiency of C could be increased up to about 100% if temperature was maintained at 700℃ and EAR was over 0.4 (or temperature at 600℃, and EAR over 0.8).Then the reaction process and mechanism of PE gasification were proposed by analyzing the characteristics of product gas.
    Electrolysis-generated ferrate at porous cylindrical cast iron anode and its application to degradation of organic wastewater
    FANG Yi, ZHENG Xi, CHEN Riyao, CHEN Zhen
    2006, 57(1):  151-154. 
    Abstract ( 530 )   PDF (536KB) ( 298 )  
    Related Articles | Metrics
    Electrolysis-generated water treatment FeO2-4 was prepared in a diaphram cell with double cathodic chamber and porous cylindrical cast iron anode.The experiment result showed that current efficiency and FeO2-4 concentration were higher by using double cylinder cast iron anode.Optimum result was obtained at J=30 mA•cm-2,30℃,14 mol•L-1 NaOH.70 mmol•L-1 FeO2-4 was produced and current efficiency was 36.8% for 5.5 h electrolysis. The result of ferrate oxidative degradation of benzidine wastewater showed removal rate of CODCr about 85% and the final products were small molecule inorganic compounds.
    能源和环境工程

    Numerical simulation of displacement ventilated room with dust on floor

    LIU Li;YOU Shijun;ZhANG Huan
    2006, 57(1):  155-159. 
    Abstract ( 803 )   PDF (1132KB) ( 230 )  
    Related Articles | Metrics
    Displacement ventilation has been considered a good function of ventilation since it can provide good indoor air quality (IAQ) and save energy.Recently it has also been used in commercial buildings.However, if the floor of the room is not clean enough and is covered with some dust, the fresh air sent from the floor level will make the dust airborne and influence indoor air quality.This paper is to study the influence of dust on floor on the IAQ of displacement ventilated room.Because it was difficult to measure the initial dust quantity and particle size,experimentally,the computational fluid dynamics (CFD) method was used in this work.The Euler-Lagrange method was used to simulate this case.The dust concentrations at different supply air velocities and different particle sizes were stuied and the deposition of dust was compared as well.The result indicated that the quantity and particle size of dust on floor should be considered when choosing the mode of ventilation.
    Effect of ultrasonic and surfactant on induction time of natural gas hydrate
    SUN Shicai, LIU Yufeng, LV Aizhong, FAN Shuanshi, XU Haiyan
    2006, 57(1):  160-162. 
    Abstract ( 577 )   PDF (469KB) ( 295 )  
    Related Articles | Metrics
    An ultrasonic system(20 kHz,0—150 W) of natural gas hydrate formation was built up to investigate the induction time of gas hydrate formation in the presence of sodium dodecyl sulfate (SDS).The experimental results indicated that the concentration of SDS solution did not affect the induction time distinctly and no critical micelle concentration(CMC) phenomenon was observed.The induction time decreased with the increase of ultrasonic power or reaction pressure.
    Preparation and performance of VSA-SA/PS fixed carrier membrane for CO2/CH4 separation
    ZHANG Ying, WANG Zhi, YI Chunhai, WANG Jixiao, WANG Shichang
    2006, 57(1):  163-168. 
    Abstract ( 598 )   PDF (1297KB) ( 213 )  
    Related Articles | Metrics
    A kind of new fixed carrier membrane material for CO2 separation, N-vinyl-γ-sodium aminobutyrate-sodium acrylate copolymer(VSA-SA), was synthesized by radical copolymerization and hydrolysis. The composite membrane was developed with VSA-SA as an active layer and polysulfone (PS) ultra-filtration membrane as the support. Several kinds of metal ion cross-linkers were used to improve the performance of the composite membrane. The effects of cross-linking time on the cross-linked membrane were also studied. The membrane performance was investigated by using feed gases with different ratios of CO2 to CH4.The results showed that the composite membrane was more suitable for the separation and removal of the natural gas with high CH4 content. The prepared membrane was stable during one week testing.
    Copolymer membrane preparation of 2-(N,N-dimethyl aminoethylme)and acrylonitrile and its gas permeance performance
    SHEN Jiangnan, WU Liguang, ZHANG Lin, CHEN Huanlin, GAO Congjie
    2006, 57(1):  169-174. 
    Abstract ( 580 )   PDF (446KB) ( 437 )  
    Related Articles | Metrics
    Poly(DM-co-AN) was synthesized by the usual radical polymerization of 2-(N,N-dimethyl aminoethyl methacrylate) and acrylonitrile.The chemical structure of the poly(DM-co-AN) was analyzed by viscosity measurement, elemental analysis , infrared spectrum(FTIR) and X-ray diffraction(XRD).The effect of reaction condition on chemical structure and the effects of carrier content, gas feed pressure and temperature on permeability of the facilitated transport membrane were investigated. The results showed that the membrane displayed a CO2 permeation rate of 3.53×10-12 cm3(STP)•cm-2•s-1•Pa-1 and CO2/CH4 ideal selectivity of 104.5 at 25℃,1140 Pa of gas pressure.Both CO2 permeation rate and selectivity of CO2/CH4 decreased with increasing pressure on feed gas.The facilitated transport mechanism of CO2 in membrane was analyzed by the infrared spectra of the membranes in different states.
    材料科学与工程

    Mathematical modeling of in-mold labeling for cooling analysis in injection molding

    SHI Xianzhang;SHEN Changyu;ZHAO Zhenfeng
    2006, 57(1):  175-179. 
    Abstract ( 604 )   PDF (679KB) ( 350 )  
    Related Articles | Metrics
    In-mold labeling processing adds a label on the part surface in mold.It is a new technology and is becoming more and more popular.It affords the mold designer far greater latitude in the design of graphics, part shape and the use of multiple molded components in a single molded unit. But the CAE technology in injection molding can’t meet the need of the new processing.There is no suitable mathematical model established for the processing.The cavity surface is always meshed in planar triangular elements. Supposing that the label and part are two plates in perfect contact,unsteady heat transfer model was established under first dissymmetry boundary for each plate.This heat transfer model was used in cooling analysis for mathematical modeling of in-mold labeling for cooling analysis in injection molding.
    Factors influencing HDI biuret particle size coated by anionic polyacrylic hydroxyl resin
    ZHOU Xinhua, TU Weiping, HU Jianqing, CUI Yingde
    2006, 57(1):  180-185. 
    Abstract ( 689 )   PDF (710KB) ( 337 )  
    Related Articles | Metrics
    HDI biuret particle coated by anionic polyacrylic hydroxyl resin was prepared by using phase-inversion technique.The morphology of composite particle was investigated by TEM.The effects of molecule mass of polyacrylic resin, the nature of solvent, styrene(ST)content, hydroxyl value and acid value on composite particle size(D) were discussed.The result indicated that composite particle had a clear core-shell structure, with hydrophobic HDI biuret as core and acrylic resin as shell.D decreased with the increase of Mn.Using methyl amyl ketone as solvent,composite particles had bimodal particle size distribution;while using methoxypropyl acetate as solvent, composite particles had a single small particle size distribution.With the increase of ST content,D decreased first, and then increased.D reached minimum when ST content in initial monomers was 10%.D increased with the increase of hydroxyl value(HV).When HV was 60 mg KOH•g-1, D decreased with the increase of acid value.While HV was above 90 mg KOH•g-1, D increased with the increase of acid value.It was concluded that a small composite particle with narrow distribution could be obtained,by decreasing the hydrogen bond force among acrylic hydroxyl chains and increasing the hydrogen bond force between acrylic hydroxyl chain and HDI biuret.
    材料科学与工程

    Syntheses and characterizations of iron-containing MCM-41

    LIU Shiquan;TAO Wenhong;XIA Guangming
    2006, 57(1):  186-191. 
    Abstract ( 630 )   PDF (459KB) ( 220 )  
    Related Articles | Metrics
    Using the incipient wetness impregnation procedure, iron was loaded in the mesopores in MCM-41 microspheres.The hybrid microspheres were decomposed by heating,producing iron-containing MCM-41 spheres with nano iron-oxygen clusters or nano-sized iron oxide particles inside the mesopores. Comparative characterizations of the iron-containing MCM-41 with different iron contents was performed.The influence of iron source on the synthesis of iron-containing MCM-41 was studied.The samples loaded with iron acetylacetonate have 3—4 times of iron content than those loaded with iron nitrate. The highest iron confent in MCM-41 was 1 mmol•g-1.The specific surface area,pore volume and pore size of the MCM-41 microspheres decreased after iron loading.In the case of loading with iron nitrate, contraction of the MCM-41 skeleton was observed after calcination, but no similar change in the case of loading with iron acetylacetonate. As far as the iron-loading content and the influence of the iron-loading on the skeleton of the mesoporous material were concerned, toluene solution of iron acetylacetonate was superior to the aqueous solution of iron nitrate as iron source for the synthesis of iron-containing MCM-41.

    Preparation and surface properties of polyurethane-fluorinated acrylate hybrid dispersions

    LI Ganghui; LI Xiaorui;SHEN Yiding
    2006, 57(1):  192-196. 
    Abstract ( 641 )   PDF (547KB) ( 375 )  
    Related Articles | Metrics
    Cationic fluorinated polyurethane-acrylate hybrid dispersions were prepared by the copolymerization of 2,2,3,4,4,4-hexafluorobutyl methacrylate, butyl acrylate and styrene in crosslinked polyurethane acetone solution via phase inversion polymerization in order to obtain polyurethane-acrylate films with low surface free energy. The structure, surface properties, particle size and morphology of FPUA water dispersions were investigated by FT-IR, TEM, submicron particle size analyzer and contact angle measurements respectively. The results showed that the introduction of fluorinated monomer could decrease the surface free energy by more than 50%, and the FPUA films cured at ambient conditions had surface free energy (lower than 0.0172 J•m-2).At the same time, the dispersion particle was spherical with particle diameter is about 220 nm.
    Kinetics and nucleation mechanism of acrylate emulsion polymerization modified by vinyl alkoxy silane
    ZHANG Xinya, HUANG Hong, LI Yongjin, SHEN Huifang, LAN Renhua, CHEN Huanqin
    2006, 57(1):  197-202. 
    Abstract ( 675 )   PDF (696KB) ( 612 )  
    Related Articles | Metrics
    The factors which influence polymeric kinetics of acrylate emulsion modified by vinyl alkoxy silane through seed emulsion polymerization were investigated, and the nucleation mechanism of emulsion polymerization was analyzed. The experimental results showed that reaction temperature, initiator concentration, emulsifier concentration and vinyl alkoxy silane amount had great influence on the kinetics of emulsion polymerization.At higher temperature, higher initiator concentration, higher emulsifier concentration and less amount of vinyl alkoxy silane monomer, the conversion rate of emulsion polymerization was higher.Besides, the pH value of the system between six and eight was favorable to emulsion polymerization kinetics.In the seed emulsion polymerization,RP∝[E]0.72RP∝[I]0.56Ea=143.92 kJ•mol-1. At the beginning of the shell reaction, nucleation of emulsion polymerization occurred in monomer droplet,while during core reaction, the nucleation mechanism was “micellar nucleation”.
    Soft-sensing model of copper liquid temperature in copper refining process and its application
    E Jiaqiang, WANG Yaonan, MEI Chi
    2006, 57(1):  203-209. 
    Abstract ( 594 )   PDF (544KB) ( 284 )  
    Related Articles | Metrics
    In order to solve measurement problem of copper liquid temperature so that qualified anode copper in the copper refining process can be obtained, some soft-sensing models of copper liquid temperature in the copper refining process including heat preservation, oxygenation and deoxidization were established based on the mechanism of heat transfer in the copper refining process, and some measures such as the pretreatment of the sampled data, the golden section method and parameter adjustment by using function link NN of the soft sensing model were introduced in the algorithm design of soft-sensing of copper liquid temperature. The application results revealed that the soft-sensing values of copper liquid temperature can describe real change of copper liquid temperature in the copper refining process. The soft-sensing model was useful for soft control of copper liquid temperature and for enhancing production efficiency and quality.
    Analysis of factors affecting preparation of SiO2 nanoparticles by ultrasonic-mechanical method
    REN Zhen, ZHENG Shaohua, JIANG Fenghua, WANG Jieqiang, WANG Xuemei
    2006, 57(1):  210-213. 
    Abstract ( 614 )   PDF (977KB) ( 355 )  
    Related Articles | Metrics
    A kind of experimental setup, named as UC-1500, was designed. SiO2 nanoparticles preparing by ultrasonic-mechanical method were studied, and the effects of ultrasound field, dispersant concentration and grinding time on grain-size and appearance of SiO2 nanoparticles were investigated. The results showed that the grain-size was smaller and the stability of SiO2 nanoparticles was better in ultrasonic field.The optimum values of such reaction factors as the space between two adjacent teeth of stirring rad, grinding time, dispersant concentration and the rotating speed of stirring rod were 15 mm, 9 h, 0.09 g•L-1 and 300 r•min-1, respectively.With grinding time being the main factor, the effects of dispersant concentration, the rotating speed of stirring rod and the space between two adjacent teeth of stirring rod decreased successively.
    Direct current electro-deposition of binary Co55Ni45 alloy nanorod arrays and its characterization
    XUE Shouhong, CAO Chuanbao, JI Fengqiu, ZHU Hesun
    2006, 57(1):  214-217. 
    Abstract ( 749 )   PDF (1347KB) ( 182 )  
    Related Articles | Metrics
    Highly ordered arrays of binary Co55Ni45 alloy nanorods with Co55Ni45 morphology were prepared by direct current electro-deposition using polycarbonate(PC) membrane template.The transmission electron microscope and scanning electron microscope observations revealed conical morphology of the nanorods.The two ends of nanorod arrays had diameters of 200 nm and 320 nm, respectively,and the nanorod arrays could be as long as 6~7 μm. The diameter of nanorod arrays depended strongly on pore diameter in PC membrane and the lengths were decided by plating parameters such as voltage, pH value, plating time and other deposition parameters. The magnetic properties and mechanism of crystals nucleation and growth in binary Co55Ni45 alloy nanorod arrays were also studied.
    Electrodialytic production of cobalt hypophosphite
    LIANG Peiyu, SONG Bingkui, ZHANG Baogui
    2006, 57(1):  218-222. 
    Abstract ( 632 )   PDF (1263KB) ( 384 )  
    Related Articles | Metrics
    A method for producing cobalt hypophosphite by contacting cobalt anode with a solution of hypophosphite anions and applying direct current through anode to cathode is introduced in this paper.A six-compartment electrodialysis cell embodying the method is described.The optimal conditions and relative technologies of producing cobalt hypophosphite are discussed during the process.There is neither solid waste residue nor discarded solution, so this method is environment friendly.
    Compartmentalization and application of morphology of branched chain explosion of fragmentation hydrogenation circulation gases
    HU Yaoyuan, YING Taokai, WU Xiaohua, LI Yong, LU Meili, JIANG Yongfu
    2006, 57(1):  223-232. 
    Abstract ( 716 )   PDF (4176KB) ( 356 )  
    Related Articles | Metrics
    The characteristics and application of the branched chain explosion of hydrocracking hydrogenation recycle gas and the relevant combustible gases were systematically studied. The explosive limits of concentration, explosive morphology, explosive waveforms and their influence factors were investigated. From the different kinds of explosive morphology and its pressure waveforms, a new idea on compartmentalization of explosive morphology for the hydrocracking hydrogenation recycle gas was introduced.Within the explosive limits, four kinds of explosive morphology (cold flame, deflagration,detonation,and transition from deflagration to detonation) could be compartmentalized and seven explosive zones (lower cold flame zone, lower deflagration zone, lower deflagration transformed into detonation zone, detonation zone,upper deflagration transformed into detonation, upper deflagration zone and upper cold flame zone) could be classified. The different mechanisms for developing the pressure waves of the explosive morphology were explored. Such knowledge is valuable for further studying the relevant system of branched-chain explosion and developing the theory of branched-chain explosion.The minimum ignition energy, the maximum experimental safe gaps, the degree of explosion danger and other
    explosion characteristics were experimentally determined. This paper also introduces the concept of ‘key components’ and pointes out that it is the key components of H2 and oxidant O2 that ignite explosion for the system consideres here.The references and methods for developing the explosion-proof safety guidelines were proposed. The results will be of significance in preventing accidents caused by mixture gas branched-chain explosion, giving directions to designing explosion-proof electric equipment and fire arresters, supervising the application of the concepts of branched-chain burning and branched-chain explosion to practice.