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SCI和EI收录∣中国化工学会会刊
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Table of Content
28 June 2008, Volume 16 Issue 3
    SPECIAL ISSUE OF THE FIRST INTERNATIONAL SYMPOSIUM ON SUSTAINABLE CHEMICAL PRODUCT AND PROCESS ENGINEERING
    A Framework for the Systematic Design of Hybrid Separation Processes
    Wolfgang Marquardt, Sven Kossack, Korbinian Kraemer
    2008, 16(3):  333-342. 
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    The design of optimal separation flow sheets for multi-component mixtures is still not a solved problem. This is especially the case when non-ideal or azeotropic mixtures or hybrid separation processes are considered. We review recent developments in this field and present a systematic framework for the design of separation flow sheets. This framework proposes a three-step approach. In the first step different flow sheets are generated. In the second step these alternative flow sheet structures are evaluated with shortcut methods. In the third step a rigorous mixed-integer nonlinear programming (MINLP) optimization of the entire flow sheet is executed to determine the best alternative. Since a number of alternative flow sheets have already been eliminated, only a few optimization runs are necessary in this final step. The whole framework thus allows the systematic generation and evaluation of separation processes and is illustrated with the case study of the separation of ethanol and water.
    Life-cycle Assessment of Carbon Dioxide Capture for Enhanced Oil Recovery
    Edgar G. Hertwich, Martin Aaberg, Bhawna Singh, Anders H. StrΦmman
    2008, 16(3):  343-353. 
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    The development and deployment of Carbon dioxide Capture and Storage(CCS)technology is a cor-nerstone of the Norwegian government's climate strategy.A number of projects are currently evaluated/planned along the Norwegian West Coast,one at Tjeldbergodden.CO2 from this project will be utilized in part for enhanced oil recovery in the Halten oil field,in the Norwegian Sea.We study a potential design of such a system.A combined cycle power plant with a gross power output of 832 MW is combined with CO2 capture plant based on a post-combustion capture using amines as a solvent.The captured CO2 is used for enhanced oil recovery(EOR).We employ a hybrid life-cycle assessment(LCA) method to assess the environmental impacts of the system.The study focuses on the modifications and operations of the platform during EOR.We allocate the impacts connected to the capture of CO2 to electricity production,and the impacts connected to the transport and storage of CO2 to the oil produced.Our study shows a substantial reduction of the greenhouse gas emissions from power production by 80% to 75 g·(kW·h)-1.It also indicates a reduction of the emissions associated with oil production per unit oil produced, mostly due to the increased oil production.Reductions are especially significant if the additional power demand due to EOR leads to power supply from the land.
    Synthesis of Pd(C4H2O4)(C4H8N2)0.5 Complex and the Catalytic Activity for Oxidative Carbonylation of Phenol
    CHENG Qingyan, LIANG Yanank, GAO Ling, WANG Yanji
    2008, 16(3):  354-356. 
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    A novel complex Pd(C4H2O4)(C4H8N2)0.5 has been synthesized by solvent thermal synthesis and used as a heterogeneous catalyst for direct synthesis of diphenyl carbonate (DPC) by oxidative carbonylation of phenol. In the reaction system of Pd(C4H2O4)(C4H8N2)0.5/Cu(OAc)2/tetrabutylammonium bromide/hydroquinone/4A molecular sieves, the effect of reaction temperature, time and CO pressure on catalytic activity were investigated, and the results revealed that the catalyst could catalyze oxidative carbonylation of phenol effectively. Under suitable reaction conditions of T=90℃, t=4 h, p(O2)=0.3 MPa, p(CO)=3.9 MPa and CH2Cl2 as solvent, the turnover number (TON) of diphenyl carbonate can reach about 13.50 (mol-DPC/mol-Pd), which is higher than the TON for pure PdCl2 under the same reaction conditions.
    Blanc Reaction of Aromatic Compounds Catalyzed by Ionic Liquids
    FANG Yanxiong, DENG Yunquan, REN Qinggang, HUANG Jingping, ZHANG Saidan, HUANG Baohua, ZHANG Kun
    2008, 16(3):  357-360. 
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    Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance of different ionic liquid catalysts for toluene chloromethylation was also studied. The reaction was found to proceed under mild conditions with excellent conversion (up to 90%) in the absence of Lewis acids. The ionic liquids could be recycled and reused without loss of their catalytic activities.
    Treatment of Dimethoate Aqueous Solution by Using Ultrasonic Airlift Loop Reactor
    LIU Yuenan, JIN Dong, LÜXiaoping, HAN Pingfang
    2008, 16(3):  361-364. 
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    Ultrasonic airlift loop reactor (UALR) shows potential and wide application for wastewater treatment. In this paper the performance and efficiency of UALR in dimethoate degradation were presented. The effects of O3 flow rate, ultrasonic intensity and initial concentration of dimethoate on degradation rate were investigated. UALR imposed a synergistic effect combining sonochemical merit with high O3 transfer rate. The results showed that UALR not only increased degradation rate, but also was better than the simple sum of degradation by O3 and ultrasound separately. Under the operation conditions of O3 flow of 0.34 m3·h-1, ultrasonic intensity 3.71 W·cm-2, and initial concentration of dimethoate at 20 mg·L-1, the degradation rate of dimethoate increased to 80%. UALR seems an advisable choice for treating organic wastewater and this process may have wide application prospect in industry.
    Sonochemical Synthesis of Maleated Rosin
    NIE Yuanmei, YAO Xingdong, LEI Fuhou
    2008, 16(3):  365-368. 
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    The cycloaddition reaction of rosin and maleic anhydride under ultrasonic irradiation has been investigated. The results show that both isomerization and Diels-Alder cycloaddition reactions were accelerated remarkably. The sonochemical reaction reached equilibrium in 5-10 min at 110℃, comparing with regular synthesis of 4-5 h over 180℃.
    Synthesis of Substituted μ-Oxo-bis[tetra-phenyl porphyrinatoiron] Compounds from Free Base Porphyrins by a One-pot Method
    SHE Yuanbin, FENG Lianshun, WANG Aixin, LI Xiuyan
    2008, 16(3):  369-372. 
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    A novel method for synthesis of substitutedμ-oxo-bis[tetraphenyl porphyrinatoiron]compounds([TRPPFe]2O) based on the reaction among free base porphyrins(TRPPH2),FeSO4·7H2O and H2O in one pot was proposed and investigated.Four kinds of[TRPPFe]2O were synthesized by this novel synthetic method,and their structures were characterized by elemental analysis,infrared spectra and UV-vis spectroscopy.The reaction conditions,including the effect of different iron salts on the formation of[TRPPFe]2O,the reaction time between FeSO4·7H2O and TRPPH2,the molar ratio of FeSO4·7H2O/TRPPH2 as well as the volume ratio of H2O/DMF,were investigated.The [TRPPFe]2O yield of 93%-98%could be obtained under the following optimal conditions:the reaction time of FeSO4·7H2O with TRPPH2 was about 10 h,the molar ratio of FeSO4·7H2O/TRPPH2 about 5:1,and the volume ratio of H2O/DMF exceeded 2:1.Further research indicated that only TRPPFeCl were formed once FeSO4·7H2O was replaced by FeCl2·4H2O,the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe]2O,suggesting that halogen ions should be avoided in this novel synthetic method.
    Oxidation of Cyclohexane Catalyzed by TS-1 in Ionic Liquid with Tert-butyl-hydroperoxide
    WANG Jianying, ZHAO Hua, ZHANG Xiangjing, LIU Runjing, HU Yongqi
    2008, 16(3):  373-375. 
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    An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with Tert-butyl-hydroperoxide catalyzed by titanium silicalite 1(TS-1)in ambient-temperature ionic liquid [emim]BF4.Good yield and higher selectivity of products were found in the ionic liquid compared with in molecular solvent.The research results showed 13.2% conversion of cyclohexane,97.6% cyclohexanol and cyclohexanone selectivity were obtained in ionic liquid under mild conditions of 90℃.
    Systematic Selection of Green Solvents for Organic Reacting Systems
    Milica Folić, Rafiqul Gani, Concepción Jiménez-González, David J. C. Constable
    2008, 16(3):  376-383. 
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    The solvent selection methodology developed earlier by Gani et al.(Comp.Chem.Eng.,2005)has been extended to handle multi-step reaction systems.The solvent selection problem was formulated based on the methodology guidelines,and solved using ICAS software tool.A list with solvent candidates is generated so that it can be further investigated experimentally.Comments and clarifications from chemists have been incorporated into the problem formulations to clarify the role of the solvents in the chemistry and potential reactivity issues.Highly promising results were obtained,in accordance with industrial process data.
    Preparation of Well-shaped Microcapsule Immobilizing Inorganic Nanoparticles
    LIU Zhengping, PEI Lixia, JI Hongbing, YAO Xingdong
    2008, 16(3):  384-388. 
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    A facile and efficient method has been developed for microencapsulation of metal oxide nanoparticles in polyurea via interfacial polymerization of toluene-2,4-diisocyanate and H2O through the atomizing emulsification approach.The resultant microcapsules were well-shaped and uniform sphere with diameter ranging from 2 to 6 μm.Thermogravimetry(TG)and differential scanning calorimetry(DSC)curves revealed that the microcapsules showed good thermal stability(no decomposition observed under 245℃).Besides,the microencapsulated TiO2 has been used as an efficient catalyst for photocatalytic degradation of methyl orange.Furthermore,the photocatalysis of immobilized TiO2 could be enhanced by introducing UV absorbing agent to the wall of microcapsules.
    Effect of Preparation Methods on Activation of Catalysts BaNi0.2Mn0.8Al11O19-δ for Dimethyl Ether Combustion
    YU Qian, YU Lin, WANG Yuanna, ZHANG Qini, SUN Ming, HUANG Yingmin, LU Yeyu, GE Zaochuan
    2008, 16(3):  389-393. 
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    Catalytic combustion of dimethyl ether(DME)over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated.The catalysts were prepared with the sol-gel method and reverse microemulsion method respectively and characterized by thermogravimetry-differential thermal analysis,X-ray diffraction and transimission electron microscope.It was found that the formation of Mn,Ni modified hexaaluminate was a relatively slow process via two solid state reactions and spinel structure was a transition phase.At the same calcined temperature and time,the catalyst prepared with the reverse microemulsion method could form the hexaaluminate phase more easily than that prepared with the sol-gel method.The catalyst BaNi0.2Mn0.8Al11O19-δ prepared with the reverse micro-emulsion method appeared a plate-like morphology,while it appeared a needle-like morphology when using the sol-gel method.The catalytic activities of catalysts BaNi0.2Mn0.8Al11O19-δ prepared with two different methods for DME combustion were tested.It showed that catalyst prepared with the reverse microemulsion method had better catalytic activity,i.e.T10% of DME had decreased by 45℃,about 90% conversion of diemthyl ether at 380℃.
    Alternative Processing Technology for Converting Vegetable Oils and Animal Fats to Clean Fuels and Light Olefins
    TIAN Hua, LI Chunyi, YANG Chaohe, SHAN Honghong
    2008, 16(3):  394-400. 
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    Since the production cost of biodiesel is now the main hurdle limiting their applicability in some areas, catalytic cracking reactions represent an alternative route to utilization of vegetable oils and animal fats. Hence, catalytic transformation of oils and fats was carried out in a laboratory-scale two-stage riser fluid catalytic cracking (TSRFCC) unit in this work. The results show that oils and fats can be used as FCC feed singly or co-feeding with vacuum gas oil (VGO), which can give high yield (by mass)of liquefied petroleum gas (LPG), C2-C4 olefins, for example 45% LPG, 47% C2-C4 olefins, and 77.6% total liquid yield produced with palm oil cracking. Co-feeding with VGO gives a high yield of LPG (39.1%) and propylene (18.1%). And oxygen element content is very low (about 0.5%) in liquid products, hence, oxygen is removed in the form of H2O, CO and CO2. At the same time, high concentration of aromatics (C7-C9 aromatics predominantly) in the gasoline fraction is obtained after TSRFCC reaction of palm oil, as a result of large amount of hydrogen-transfer, cyclization and aromatization reactions. Additionally, most of properties of produced gasoline and diesel oil fuel meet the requirements of national standards, containing little sulfur. So TSRFCC technology is thought to be an alternative processing technology leading to production of clean fuels and light olefins.
    Peanut Shell Activated Carbon:Characterization, Surface Modification and Adsorption of Pb2+ from Aqueous Solution
    XU Tao, LIU Xiaoqin
    2008, 16(3):  401-406. 
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    Metal ion contamination of drinking water and waste water, especially with heavy metal ion such as lead, is a serious and ongoing problem. In this work, activated carbon prepared from peanut shell (PAC) was used for the removal of Pb2+ from aqueous solution. The impacts of the Pb2+ adsorption capacities of the acid-modified carbons oxidized with HNO3 were also investigated. The surface functional groups of PAC were confirmed by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Boehm titration. The textural properties (surface area, total pore volume) were evaluated from the nitrogen adsorption isotherm at 77 K. The experimental results presented indicated that the adsorption data fitted better with the Langmuir adsorption model. A comparative study with a commercial granular activated carbon (GAC) showed that PAC was 10.3 times more efficient compared to GAC based on Langmuir maximum adsorption capacity. Further analysis results by the Langmuir equation showed that HNO3 [20% (by mass)] modified PAC has larger adsorption capacity of Pb2+ from aqueous solution (as much as 35.5 mg·g-1). The adsorption capacity enhancement ascribed to pore widening, increased cation-exchange capacity by oxygen groups, and the promoted hydrophilicity of the carbon surface.
    Optimization of Synthesis of Spherical Lignosulphonate Resin and Its Structure Characterization
    FAN Juan, ZHAN Huaiyu
    2008, 16(3):  407-410. 
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    Calcium lignosulphonate was used to synthesize a spherical lignosulphonate resin in a cheap and non-toxic disperse medium by reversed phase suspension polymerization.The process conditions were optimized by orthogonal experiments.Under the optimal conditions(T=95℃,cHCl=3 mol·L-1,mHCHO:mCLS=7%,wCLS=50%),globulation took about 20 min and the product was featured with excellent spherical shape,narrow particle size range,61.20%of water retention capacity,0.83 mmol·ml-1 of total volume exchange capacity and 3.46 mmol·g-1 of total exchange capacity.The results of Scanning Electron Micrograph and Scanning Probe Micrograph indicate that spherical lignosulphonate resin has a rugged surface with porous microstructure in the gel skeleton.The aver-age pore size of dry samples was determined to be 10.46 nm by the BET method.
    Preparation and Characterization of a Perovskite-type Mixed Conducting SrFe0.6Cu0.3Ti0.1O3-δ Membrane for Partial Oxidation of Methane to Syngas
    DONG Xinfa, ZHANG Heng, LIN Weiming
    2008, 16(3):  411-415. 
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    Dense membrane with the composition of SrFe0.6Cu0.3Ti0.1O3-δ (SFCTO) was prepared by solid state reaction method.Oxygen permeation flux through this membrane was investigated at operating temperature ranging from 750℃ to 950℃ and different oxygen partial pressure.XRD measurements indicated that the compound was able to form single-phased perovskite structure in which part of Fe was replaced by Cu and Ti.The oxygen desorption and the reducibility of SFCTO powder were characterized by thermogravimetric analysis and temperature programmed reduction analysis,respectively.It was found that SFCTO had good structure stability under low oxygen pressure at high temperature.The addition of Ti increased the reduction temperature of Cu and Fe.Performance tests showed that the oxygen permeation flux through a 1.5 mm thick SFCTO membrane was 0.35-0.96 ml·min-1·cm-2 under air/helium oxygen partial pressure gradient with activation energy of 53.2 kJ·mol-1.The methane conversion of 85%,CO selectivity of 90% and comparatively higher oxygen permeation flux of 5 ml·min-1·cm-2 were achieved at 850℃,when a SFCTO membrane reactor loaded with Ni-Ce/Al2O3 catalyst was applied for the partial oxidation of methane to syngas.
    Multiscale Characterization of Automotive Surface Coating Formation for Sustainable Manufacturing
    Jie XIAO, Jia LI, Cristina Piluso, Yinlun HUANG
    2008, 16(3):  416-423. 
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    Automotive surface coating manufacturing is one of the most sophisticated and expensive steps in automotive assembly.This step involves generating multiple thin layers of polymeric coatings on the vehicle sur-face through paint spray and curing in a multistage,dynamically changing environment.Traditionally,the quality control is solely post-process inspection based,and process operational adjustment is only experience based,thus the manufacturing may not be(highly)sustainable.In this article,a multiscale system modeling and analysis meth-odology is introduced for achieving a sustainable application of polymeric materials through paint spray and film curing in automotive surface coating manufacturing.By this methodology,the correlations among paint material, application processes and coating performance can be identified.The model-based analysis allows a comprehensive and deep study of the dynamic behaviors of the material,process,and product in a wide spectrum of length and time.Case studies illustrate the efficacy of the methodology for sustainable manufacturing.
    A Property Based Approach for Simultaneous Process and Molecular Design
    Fadwa Tahra Eljack, Charles Conrad Solvason, Nishanth Chemmangattuvalappil, Mario Richard Eden
    2008, 16(3):  424-434. 
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    In this work,property clustering techniques and group contribution methods are combined to enable simultaneous consideration of process performance requirements and molecular property constraints.Using this methodology,the process design problem is solved to identify the property targets corresponding to the desired process performance.A significant advantage of the developed methodology is that for problems that can be satisfactorily described by only three properties,the process and molecular design problems can be simultaneously solved visually on a ternary diagram,irrespective of how many molecular fragments are included in the search space.On the ternary cluster diagram,the target properties are represented as individual points if given as discrete values or as a region if given as intervals.The structure and identity of candidate components is then identified by combining or"mixing"molecular fragments until the resulting properties match the targets.
    Development of Sustainable Solutions for Zebra Mussel Control Through Chemical Product Engineering
    R. Costa, P. Elliott, P. M. Saraiva, D. Aldridge, G. D. Moggridge
    2008, 16(3):  435-440. 
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    The zebra mussel is an important aquatic pest that causes great damage to freshwater-dependent indus-tries,due to biofouling.The main goal of the project discussed here is to develop improved solutions to control this species.Three approaches have been explored in an attempt to design innovative application strategies for existing biocides:(i)encapsulation of toxins;(ii)combination of toxins;(iii)investigation of the seasonal variation of the species' tolerance to toxins.In this paper,the principles behind these approaches and the major results on each topic are presented.The benefits of adopting a chemical product engineering approach in conducting this project are also discussed.
    Performance of Nanofiltration and Reverse Osmosis Membranes in Metal Effluent Treatment
    LIU Feini, ZHANG Guoliang, MENG Qin, ZHANG Hongzi
    2008, 16(3):  441-445. 
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    The performance of different nanofiltration(NF)and reverse osmosis(RO)membranes was studied in treating the toxic metal effluent from metallurgical industry.The characteristics and filtration behavior of the processes including the wastewater flux,salt rejection and ion rejection versus operating pressure were evaluated.Then the wastewater flux of RO membrane was compared with theoretical calculation using mass transfer models,and good consistency was observed.It was found that a high rejection rate more than 95% of metal ions and a low Chemical Oxygen Demand(COD)value of 10 mg·L-1 in permeate could be achieved using the RO composite membrane,while the NF rejection of the salt could be up to 78.9% and the COD value in the permeate was 35 mg·L-1. The results showed that the product water by both NF and RO desalination satisfied the State Reutilization Qualification,but NF would be more suitable for large-scale industrial practice,which offered significantly higher permeate flux at low operating pressure.
    Mechanism of Chrome-free Tanning with Tetra-hydroxymethyl Phosphonium Chloride
    SHAO Shuangxi, SHI Kaiqi, LI Ya, JIANG Lan, MA Chun'an
    2008, 16(3):  446-450. 
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    Tetra-hydroxymethyl phosphonium chloride(THPC)has been considered as an important chrome-free tanning agent.To understand the THPC tanning mechanism,the structure,charge distribution,activity and tanning ability of each phosphorous compound in THPC tanning system were studied,by 31P NMR,FT-IR spectroscopy, differential scanning calorimetry(DSC)and computational chemistry method,etc.When pH raised to 6.0,the decomposition of THPC would take place,which results in a production of free formaldehyde,tri-hydroxymethyl phosphonium(TrHP)and tri-hydroxymethyl phosphine oxide(TrHPO).At pH 9.0,THPC will be converted completely to TrHP and most TrHP is further oxidized into TrHPO.It is possible that,in reaction of phosphorous compounds and collagens,both P—C and C—O bonds would break simultaneously or individually.From molecular charge distribution and bond polar properties,it is deduced that,if P C bonds break,the activity is in order of TrHPO>THPC>TrHP,whereas if C—O bonds break,the order is TrHP>THPC>TrHPO.It is more possible that P—C bonds will break in reaction with collagen,and TrHPO may be more active in the THPC tanning system.The results of tanning and DSC also prove the above conclusion.Furthermore,the fact that the shrinkage temperature of THPC tanned leather was below 70℃ when basified to pH 5.0 or lower suggests that the hydroxymethyl groups of THPC and TrHP are less possible to combine directly with amino groups of collagen.
    Preparation and Analysis of Fe3O4 Magnetic Nanoparticles Used as Targeted-drug Carriers
    ZHAO Yuanbi, QIU Zumin, HUANG Jiaying
    2008, 16(3):  451-455. 
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    Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3·6H2O and FeCl2·4H2O with addition of ammonium hydroxide.The conditions for the preparation of Fe3O4 magnetic nanoparticles were optimized,and Fe3O4 magnetic nanoparticles obtained were characterized systematically by means of transmission electron microscope(TEM),dynamic laser scattering analyzer(DLS)and X-ray diffraction(XRD). The results revealed that the magnetic nanoparticles were cubic shaped and dispersive,with narrow size distribution and average diameter of 11.4 nm.It was found that the homogeneous variation of pH value in the solution via the control on the dropping rate of aqueous ammonia played a critical role in size distribution.The magnetic response of the product in the magnetic field was also analyzed and evaluated carefully.A 32.6 mT magnetic field which is produced by four ferromagnets was found to be sufficient to excite the dipole moments of 0.05 g Fe3O4 powder 2 cm far away from the ferromagnets.In conclusion,the Fe3O4 magnetic nanoparticles with excellent properties were competent for the magnetic carriers of targeted-drug in future application.
    Amino Acids Production from Fish Proteins Hydrolysis in Subcritical Water
    ZHU Xian, ZHU Chao, ZHAO Liang, CHENG Hongbin
    2008, 16(3):  456-460. 
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    The hydrolysis technology and reaction kinetics for amino acids production from fish proteins in subcritical water reactor without catalysts were investigated in a reactor with volume of 400 ml under the conditions of reaction temperature from 180-320℃,pressure from 5-26 MPa,and time from 5-60 min.The quality and quantity of amino acids in hydrolysate were determined by bioLiquid chromatography,and 17 kinds of amino acids were obtained.For the important 8 amino acids,the experiments were conducted to examine the effects of reaction temperature,pressure and time on amino acids yield.The optimum conditions for high yield are obtained from the experimental results.It is found that the nitrogen and carbon dioxide atmosphere should be used for leucine,isoleucine and histidine production while the air atmosphere might be used for other amino acids.The reaction time of 30 min and the experimental temperature of 220℃,240℃ and 260℃ were adopted for reaction kinetic research.The total yield of amino acids versus reaction time have been examined experimentally.According to these experimental data and under the condition of water excess,the macroscopic reaction kinetic equation of fish proteins hydrolysis was obtained with the hydrolysis reaction order of 1.615 and the rate constants being 0.0017,0.0045 and 0.0097 at 220℃,240℃ and 260℃ respectively.The activation energy is 145.1 kJ·mol-1.
    Recovery Technology of DMF from Wet Type Polyurethane Synthetic Leather Waste Gas
    ZHAO Shunhua, SONG Xijin, PEI Ning, ZHANG Jingzhu, LIU Shuqing
    2008, 16(3):  461-464. 
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    A new recovery technology is developed to recycle N,N-dimethyl formamide(DMF)in waste gas from wet type polyurethane synthetic leather industry.Given that the concentration of DMF in waste gas was as low as 325.6-688.3 mg·m-3,it was necessary to make sure two phases contact adequately and strengthen the mass transfer by increasing contact area and enhancing the turbulence.Therefore,two-stage countercurrent absorption and two-stage fog removing system were introduced into the technology.The top section of the absorption column was filled with structured wire-ripple stainless steel packing BX500,while the lower section with sting-ripple packing CB250Y.Total height of packing material was 6 m.In addition,there were both two-stage fog removing layer and high efficiency liquid distributor at the column top.All the operating parameters,including temperature,pressure, flow rate and liquid position,could be controlled by computers without manual operation,making sure the outlet gas achieved the national emission standard that the DMF concentration should be below 40 mg·m-3.The whole equipment could recover 237.6 t of DMF each year,with the profit up to CNY 521×103.
    Tuning the Morphology of Pharmaceutical Compounds via Model Based Solvent Selection
    Arunprakash T. Karunanithi, Charles Acquah, Luke E. K. Achenie
    2008, 16(3):  465-473. 
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    In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model.A three-stage approach involving a pre-design stage,a product design stage and a post-design experimental verification stage is presented.The pre-design stage addresses the formulation of the property constraint for crystal morphology.This involves crystallization experiments and development of property models and constraints for morphology.In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming model.The design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage,in the post design experimental verification stage,the morphology of the crystals (precipitated from the designed solvent)is verified through crystallization experiments followed by product characterization via scanning electron microscopy,powder X-ray diffraction imaging and Fourier transform spectra analysis.
    Synthesis and Scheduling of Optimal Batch Water-recycle Networks
    Arwa H. Rabie, Mahmoud M. El-Halwagi
    2008, 16(3):  474-479. 
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    This work develops an optimization-based methodology for the design and scheduling of batch water recycle networks.This task requires the identification of network configuration,fresh-water usage,recycle assignments from sources to sinks,wastewater discharge,and a scheduling scheme.A new source-tank-sink representation is developed to allow for storage and dispatch tanks.The problem is solved in stages by first eliminating scheduling constraints and determining minimum usage of fresh water and wastewater discharge.An iterative procedure is formulated to minimize the total annual cost of the system by trading off capital versus operating costs. The work overcomes limitations in previous literature work including restricted recycle within the same cycle, lumped balances that may not lead to feasible solutions,and unrealistic objective functions.A case study is solved to illustrate the usefulness of the devised procedure.
    Improving Energy Performance of Water Allocation Networks Through Appropriate Stream Merging
    FENG Xiao, LI Yucai, YU Xinjiang
    2008, 16(3):  480-484. 
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    Water-using operations in the process industry have demands for water usually both on water quality and temperature,and the existing mathematical models of heat exchange networks cannot guarantee the energy performance of a water network optimal.In this paper,the effects of non-isothermal merging on energy performance of water allocation networks are analyzed,which include utility consumption,total heat exchange load,and number of heat exchange matches.Three principles are proposed to express the effects of non-isothermal merging on energy performance of water allocation networks.A rule of non-isothermal merging without increasing utility consumption is deduced.And an approach to improve energy performance of water allocation network is presented. A case study is given to demonstrate the method.
    Boron Nitride Nanowires Produced on Commercial Stainless Steel foil
    CHEN Yongjun, TONG Zhangfa, LUO Lijie
    2008, 16(3):  485-487. 
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    Chemical vapor deposition growth of one-dimensional nanomaterials usually demands substrates that have been coated with a layer of catalyst film. In this study, a green process to synthesize boron nitride (BN) nanowires directly on commercial stainless steel foils was proposed by heating boron and zinc oxide powders under a mixture gas flow of N2 and 15% H2 at 1100℃, and a large quantities of pure h-BN nanowires have been produced directly on commercial stainless steel foil. The stainless steel foils not only acted as the substrate but also the catalyst for the nanowire growth. The synthesized BN nanowires were characterized by X-ray diffraction, scanning and transmission electron microscopes, X-ray energy dispersive spectrometer and photoluminescence spectroscopy. The nanowires also possess strong PL emission bands at 515, 535, and 728 nm.
    Synthesis and Ionic Conduction of Cation-deficient Apatite La9.33-2x/3MxSi6O26 Doped with Mg,Ca,Sr
    YUAN Wenhui, GU Yaping, LI Li
    2008, 16(3):  488-491. 
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    Apatite-type lanthanum silicate with special conduction mechanism via interstitial oxygen has attracted considerable interest in recent years. In this work, pure powder of La9.33-2x/3MxSi6O26 (M=Mg, Ca, Sr) is prepared by the sol-gel method with sintering at 1000℃. The powder is characterized by X-ray diffraction (XRD) and scanning electron micrograph (SEM). The apatite can be obtained at relatively low temperature as compared to the conventional solid-state reaction method. The measurements of conductivity of a series of doped samples La9.33-2x/3MxSi6O26 (M=Ca, Mg, Sr) indicate that the type of dopant and the amount have a significant effect on the conductivity. The greatest decrease in conductivity is observed for Mg doping, following the Ca and the Sr doped apatites. The effect is ultimately attributed to the amount of oxygen interstitials, which is affected by the crystal lattice distortion arising from cation vacancies.
    Heat Transfer of Boiling R134a and R142b on a Twisted Tube with Machine Processed Porous Surface
    GAO Xuenong, YIN Huibin, HUANG Yuyou, LING Shuangmei, ZHANG Zhengguo, FANG Yutang
    2008, 16(3):  492-496. 
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    The objective of this work was to investigate nucleate pool boiling heat transfer performance and mechanism of R134a and R142b on a twisted tube with machine processed porous surface(T-MPPS tube)as well as to determine its potential application to flooded refrigerant evaporators.In the experimental range,the boiling heat transfer coefficients of R134a on a T-MPPS tube were 1.8-2.0 times larger than those of R134a on a plain tube. In addition,the developed experimental correlations verified that the predictions of the heat transfer coefficients of boiling R134a and R142b on a T-MPPS tube at the experimental conditions were considerably accurate.