Please wait a minute...
Table of Content
05 December 2011, Volume 62 Issue 12
    综述与专论
    Research advances in property integration
    <DENG Chun1,FENG Xiao2
    2011, 62(12):  3309-3315. 
    Abstract ( 1477 )   PDF (934KB) ( 970 )  
    Related Articles | Metrics

    Property integration is a property-based holistic approach to allocate and manipulate streams and processing units, track, adjust, assign and match properties throughout the process.It is a novel system design approach and new branch of process integration.This paper reviewed the recent research advances in single-property integration, graphical approach and mathematical approach for multi-property integration and simultaneous process and molecular design via property integration.The property pinch and ternary graphical approach for property integration are introduced in detail.Finally, several future research suggestions are given.

    热力学
    Predicting melting point of imidazolium-based ionic liquids using modified group-contribution by mass connectivity index
    <XIONG Yan, DING Jing,YU Dahong, PENG Changjun, LIU Honglai
    2011, 62(12):  3316-3322. 
    Abstract ( 1626 )   PDF (501KB) ( 604 )  
    Related Articles | Metrics

    Researches on ionic liquids (ILsare attractive due to ILs unique characteristics, while an important drawback in the application of ILs is the scarcity of their thermodynamic data.The number of potential ILs is so enormous, some say as many as 1012 to 1018, that it is impossible to determine all these data by experimental methods.Many attempts, including group-contribution and connectivity index have had some success to develop methods to estimate the physical properties of unknown ILs in order to facilitate the design of new modifications and reduce the need for experimental work.A new concept named mass connectivity index to encode bond contributions and to allow quantifying the extent of branching in a molecule, especially in ILs, was proposed in 2010.The preliminary study showed that there was a close but complicated relationship between mass connectivity index and the melting point of ILs, implying that it was hard to predict the melting point only by mass connectivity index without the available information supplied by the other models.In this paper, a new group-contribution model combined with mass connectivity index was proposed for the prediction of the melting point of imidazolium-based ionic liquids, which adopted successful group-contribution parameters and distinguished structure characteristics of ILs by mass connectivity index considering the influence of structure on melting points.It was the first attempt to introduce the concept of mass connectivity index to group-contribution method to estimate melting point. In the model, 23 basic group contribution parameters of ILs and 3 structure characteristic factors were defined except for mass connectivity index and all the constants needed were determined by regression analysis of 62 typical data points obtained from available experimental data in the literatures.The melting points of other 59 ILs not used for determining the parameters of the equation were predicted by the new method and all the 121 data points were collected and compared with both experimental data and those predicted by single group-contribution method to check the predictive capabilities of the model.The average derivation for both correlation and prediction of melting temperature of 121 ILs was 5.15%, R2 and RMSD were 0.8686 and 20.75 K respectively.The statistical parameters supported the conclusion that the value of melting points could be estimated with good accuracy by the proposed model.

    流体力学与传递现象
    Modeling and simulation of vacuum evaporation from surface of a continuous falling liquid column
    <,<,<,<,
    2011, 62(12):  3323-3329. 
    Abstract ( 1607 )   PDF (1038KB) ( 1363 )  
    Related Articles | Metrics

    Modeling and simulation of vacuum evaporation from the surface of a continuous falling liquid column were carried out to obtain a mechanism-based prediction for application in energy-efficient vapor-liquid separation process.The parameters governing the continuous flow of falling liquid column out-of an orifice were investigated to determine the critical conditions for breakup of the liquid column.The mechanism of evaporation from the free surface of liquid column was analyzed and a mathematical model of the system was set up.The simulation results were in good agreement with the experimental data.In an adiabatic flash vaporization, the temperature gradient near the interface on the liquid side was a sensitive indicator of evaporation rate.This means that the resistance of heat transfer mainly lies in the liquid phase, so that the evaporation rate can be enhanced by increasing the liquid velocity out-of the orifice and narrowing the orifice diameter but without the breakup of liquid column, or increasing the degree of superheat.

    CFD simulation and time series analysis of granular temperature in gas-solids dense phase fluidized bed
    <,<,<,<,
    2011, 62(12):  3330-3336. 
    Abstract ( 1321 )   PDF (987KB) ( 735 )  
    Related Articles | Metrics

    The Euler-Euler two-fluid model combined with kinetic theory of granular flow was used to simulate the gas-solids dense phase fluidized bed at different superficial velocities.The experiments were carried out to compare the profile of pressure and pressure fluctuation power spectrum with the CFD simulated results, and the simulation method was validated.Statistical analysis and spectral analysis were used to investigate the granular temperature time series.It was shown that as superficial velocity increased, average and standard deviation of granular temperature time series increased, while flatness factor almost remained constant.By integrating acoustic energy theory into granular temperature and referring to acoustic energy profile with bed height,the average, standard deviation and flatness factor of granular temperature time series were used to determine the stagnant zone of particle motion.Furthermore, granular temperature spectrum was introduced and divided into energy-containing scale, inertial scale and dissipation scale based on the cascade theory of fluctuation energy.In the inertial scale, granular temperature spectrum deviated from Kolmogorov -5/3 law and tended to obey Levy-Kolmogorov law.In the application scope of Levy-Kolmogorov law, the decay index of inertial scale in the stagnant zone achieved a maximum, according to which the identification of stagnant zone by the decay index of granular temperature spectrum was proposed.

    Local particle mean velocity measurement using electrostatic sensor matrix
    <LI Jian, XU Chuanlong, WANG Shimin
    2011, 62(12):  3337-3344. 
    Abstract ( 1459 )   PDF (3660KB) ( 872 )  
    Related Articles | Metrics

    Particle velocity is an important parameter describing the flow state of gas-solids two-phase flow. A new spatial filtering method based on arc-shaped electrostatic sensor matrix was proposed for measuring local particle mean velocity of gas-solids two-phase flow.The sensing zone of each linear electrostatic sensor array was analyzed by using the finite element method.The relationship between the frequency spectrum characteristics of output signal of spatial filter matrix and particle velocity was obtained. A measurement system based on the arc-shaped electrostatic sensor matrix was developed. Performance of the measurement system was evaluated on a gravity-fed particles flow apparatus.The results of the particle velocity measurement indicated that each linear electrostatic sensor array of the matrix had its own sensing zone, and its output signal reflected the mean velocity of the particles in the zone.The system repeatability was within ±11%.Theoretical and experimental results demonstrated that the method was feasible.

    Simulation of bubbly flow heat transfer in a serpentine tube
    <,<,
    2011, 62(12):  3345-3351. 
    Abstract ( 1229 )   PDF (3053KB) ( 1303 )  
    Related Articles | Metrics

    This work numerically investigated bubbly flow with phase change in a horizontal serpentine tube.A volume of fluid (VOF)multiphase model was used to study unsteady laminar flow in the tube.The phase change between liquid and vapor phases was modeled by using heat and mass sourses in the governing equations, and was numerically implemented by using UDFs.The model was first validated with experiments in terms of flow pattern and then used for this study.The results showed that the mixing effect of secondary flow at bends caused a quick recovery of temperature at the top wall after the passage of bubble when the bubble entry frequency was extremely low, and effectively increased the temperature at the top wall by bringing hot fluid from the bottom to the top when the bubble entry frequency was relatively large.As a single bubble passed the straight sections of the tube, it absorbed the heat for evaporation and cooled down the top wall.The top wall recovered its temperature slowly becasue the main heat input was from the local heat flux.However, in the bend sections, the top wall temperature recovered quickly after the passage of bubble due to secondary flow caused by centrifugal force.Secondary flow quickly brought hot fluid from other regions to heat the top wall, causing a quick recovery of temperature.When a series of bubbles passed the tube, the entire top region of the tube was effectively cooled.The variation in temperature during the passage of bubble was smaller in the straight sections compared to the bend sections.This was because the temperature level was lower in the straight sections but higher in the bend sections because secondary flow effectively brought hot fluid from the bottom regions of the tube to the top regions.The series of bubbles effectively enhanced heat transfer of the serpentine tubes relatively to single phase liquid flow.

    Shell-side fluid flow field in shell-and-tube heat exchanger with multi-parallel-channel
    <,
    2011, 62(12):  3352-3360. 
    Abstract ( 1479 )   PDF (3984KB) ( 1388 )  
    Related Articles | Metrics

    The decrease in length-diameter ratio may lead to some technical problems in shell-and-tube heat exchangers, such as fluid flow maldistribution, sharp increase of pressure drop, and performance deterioration.In order to solve above problems, two techniques are proposed in this study, application of a novel structure of multi-parallel-channel inlet/outlet (MPCand installation of fluid flow distributors (FDBsin the region of inlet/outlet in shell-side.The shell-side fluid flow is simplified according to its structural characteristics and the unit duct model is established.By employing commercial CFD software of FLUENT 6.3, the numerical investigation on shell-side fluid flow was carried out.The numerical model and method were confirmed by experiment.Without FDBs and with FDBs of different punching ratios, both shell-side velocity distribution and resistance were investigated with different values of Reynolds number and number of tube rows (N).Without FDBs, as N decreases, the distribution of shell-side is effectively improved and the resistance is reduced sharply, with more than 70% of total pressure drop reduced when N decreases from 11 to 7 at the same Re.FDBs improve the shell-side fluid distribution effectively, but increase the shell-side pressure drop.The comparison shows that the fluid flow distributor with the best fluid flow distribution gives the largest pressure drop, about 10%12% larger than that without FDB and about 4%6% larger than that with other two FDBs.The largest pressure drop of shell-side is generated in the regions of inlet and outlet.

    Development of hydrodynamic model for gas-liquid two-phase flow for complex pipeline profiles
    <,
  • 2011, 62(12):  3361-3366. 
    Abstract ( 1244 )   PDF (586KB) ( 559 )  
    Related Articles | Metrics

    With the production of the Puguang gas field, low-liquid-loading gas-oil two-phase flow present in wet gas pipelines is one of the typical occurrences of three-phase flow in the oil and gas industry.Wet gas transportation pipelines often contain water and hydrocarbon condensates, which leads to the occurrence of low-liquid-loading three-phase flow.However, small amounts of condensates can lead to a significant increase in pressure drop along a pipeline.In-situ liquid holdups are important for determining pigging frequency and designing receiving facilities.The development of a hydrodynamic model for the wet gas gathering pipelines has become a key problem.According to fluid hydrodynamics, a hydrodynamic model for complex terrain was developed, and the closure correlationships corresponding to the model were given, which was suitable for the calculation of the low-liquid-loading two-phase flow in pipelines.The indoor test was done to verify the pressure and liquid holdup calculations.With the experimental data, the gas-wall friction factor, gas-oil interfacial friction factor and gas-liquid interface shape relationships were optimized, and a new gas-oil interfacial friction factor combined relationship and gas-liquid interface shape was established. By the comparative analysis of calculation model and experimental data, the proposed flow pattern criteria and the model for liquid holdup and pressure gradient were validated.The field production results were also collected to test the calculated results of the model.The pressure results were in the relative  error ±5%, the accumulated liquid results were in the relative error ±10%, which agreed fairly well with the production data.The developed model can be used for low-liquid-loading calculation.

  • Effects of baffle connection manner on shell-side performance of heat exchanger with helical baffles
    <,<,<,
    2011, 62(12):  3367-3372. 
    Abstract ( 1167 )   PDF (1071KB) ( 686 )  
    Related Articles | Metrics

    A 3D numerical investigation for heat exchanger with helical baffles was carried out to study the effects of baffle connection manner on shell-side flow and heat transfer characteristics under the same helical pitch.The results show that both the shell-side heat transfer coefficient and pressure drop decrease with the increase of the overlap size at certain mass flow rate.The latter decreases more quickly than the former.When the baffles are arranged in a continuous manner, the leakage from the triangle zone increases the velocities of fluid flowing across the tube bundle perpendicularly and along the tubes in the central zone, but the overall velocity distribution is non-uniform and the flow on the leeward side is poor.As the overlap size increases, the leakage from the marginal triangle zone increases the velocity in the region near the shell so that the flow field is improved.The heat flux on the central tubes is much lower and the heat transfer is more uniform along the radial direction when the adjacent baffles are connected in an overlapped manner compared with the case when the adjacent baffles are arranged in a continuous manner.

    Hydrodynamics of turbulent slurry bubble column ()Modeling and simulation of bubble column with vertical pipe bundles
    <ZHANG Yu, LI Hongbo, LI Zhaoqi, WANG Lijun, LI Xi
    2011, 62(12):  3373-3380. 
    Abstract ( 1042 )   PDF (512KB) ( 134 )  
    Related Articles | Metrics

    The commercial-scale slurry bubble column reactors are generally equipped with bundles of vertical heat-exchange pipes.Experimental results showed that existence of the pipe bundles led to steepening of liquid velocity and gas holdup distributions, the so-called funneling effect.At present, there is still lack of reliable CFD models which quantitatively describe the impact of vertical pipe bundles.In this work, a novel hydrodynamic model was developed, with two new ideas.The influence of pipe bundles was regarded as volumetric sources instead of rigid wall boundaries, thus actions of internals on the flow were transformed to additional constitutive equations for momentum source, turbulent energy source and energy dissipation source in standard k-ε equations.For the determination of radial gas holdup profiles, the lateral lift force and turbulent dispersion force imposed on bubble swarms were introduced into the radial momentum balance equation.The new introduced pipe resistance coefficients in the CFD model came from literatures, only two parameters involving radial force and turbulent energy dissipation were determined by fitting experimental data.Radial profiles of gas holdup and liquid velocity predicted by the CFD model showed good agreements with experimental data.The model presented in this paper provides an effective tool for simulating the funnel effect and impacts of the pipe bundles on bubbly flow.

    Distribution of heat transfer coefficient in horizontal-tube falling film evaporator
    <SHEN Shengqiang, LIANG Gangtao, GONG Luyuan, MU Xingsen, LIU Rui, LIU Xiaohua
    2011, 62(12):  3381-3385. 
    Abstract ( 1295 )   PDF (389KB) ( 695 )  
    Related Articles | Metrics

    A set of experimental facilities was set up to measure the heat transfer coefficient of horizontal-tube falling film evaporator.The effects of spray density on the topmost row Γ and evaporating temperature T on the overall heat transfer coefficient K are studied.The heat transfer coefficient distribution in the evaporator is presented.The results indicate that increase of spray density and evaporating temperature helps to enhance the value of K.Along the axial direction of the tube, K increases at the first 5 m and then decreases in the following 3 m, mainly caused by the condensation inside the tube.The K value decreases from the upper rows to the lower rows.In addition, increase of number of tube rows reduces the K value, especially at low spray density.

    Heat exchange characteristics of zeotropic mixtures in heat exchangers in high temperature heat pump
    <,<,
    2011, 62(12):  3386-3393. 
    Abstract ( 1284 )   PDF (482KB) ( 708 )  
    Related Articles | Metrics

    Zeotropic mixtures are popular alternatives to chlorofluorocarbons (CFCsand hydrochlorofluorocarbons (HCFCsin the high temperature heat pump system.Zeotropic mixtures exhibit two major characteristics during phase changetemperature gliding and nonlinear relationship between temperature and enthalpy.In order to reveal the distribution of temperature difference between zeotropic mixture and heat transfer fluid in heat exchangers and get clear how temperature differences affect the performance of the system, experiments were carried out with the binary mixture Z1 in the high temperature water-water heat pump system, which was composed of 17% R290 and 83% R600 (mass ratio).The experimental results showed that as the water flow rate decreased the maximum temperature difference occurred in the condenser and its location moved to the cold end of the condenser, while the minimum temperature difference occurred in the evaporator and its location moved to the cold end of the evaporator.It was found that the occurrence of maximum temperature difference decreased the coefficient of performance of the system and increased the exergy loss caused by irreversible heat transfer in the condenser, while the occurrence of pinch point increased the coefficient of performance of the system and decreased the exergy loss caused by irreversible heat transfer in the evaporator.The results demonstrate the importance and the need for pinch point analysis in the evaluation of zeotropic refrigerant mixtures applied in air-conditioner or heat pump.In addition, the change of the temperature difference between the working fluid and heat transfer media found in this study is helpful to design heat exchangers in heat pump units.

    Convection heat transfer with forced air flow across staggered tube bank embedded in porous metal foam
    <LI Juxiang1, TU Shan-Tung2
    2011, 62(12):  3394-3398. 
    Abstract ( 1306 )   PDF (940KB) ( 516 )  
    Related Articles | Metrics

    The convection heat transfer of forced air flow across a triangle staggered tube bank embedded in porous metal foam was investigated experimentally.The results show that the resistance of fluid flow increases obviously because of the porous metal foam, but the increase rate decreases with the increase of Reynolds number.Porous metal foam greatly enhances the convection heat transfer.The enhancement effect decreases with the increase of Reynolds number.In the experimental range, the flow resistance increases 10.10912.727 times that of plain tube bank, while the enhancement of convection heat transfer is 2.082.78 times.The correlations for non-dimensional resistance coefficient and the Nusselt number are obtained in the experimental range.It is concluded that the porous metal foam is more suitable for the low velocity of fluid from aspects of heat transfer enhancement and flow resistance.

    Numerical simulation of liquid-solid slurry flow in horizontal pipeline
    <WANG Jihong1, ZHANG Tengfei1, WANG Shugang1, LIANG Yuntao2
    2011, 62(12):  3399-3404. 
    Abstract ( 1388 )   PDF (751KB) ( 1295 )  
    Related Articles | Metrics

    A two fluids computational fluid dynamics (CFDmodel was developed to describe the hydrodynamics of liquid-solid slurry flow in horizontal pipeline based on the kinetic theory of granular flow.Researches have revealed that interphase force is closely related to interphase momentum transfer and affects the accuracy of the model.In a fully developed turbulent flow region, drag force and turbulent dispersion force directly affect interphase momentum transfer between solid and liquid, and by introducing such forces the particle concentration simulation tends to be reasonable.The two fluids CFD model based on the kinetic theory of granular flow prevails over current models for various particle concentrations in engineering field.

    Influence of potassium acetate on coke formation during cracking of light naphtha
    <,QU Ruibo1
    2011, 62(12):  3405-3410. 
    Abstract ( 1889 )   PDF (1888KB) ( 561 )  
    Related Articles | Metrics
    To study the influence of alkali metal on coke formation, a coking test was carried out on the inner surface of a used 25Cr35Ni cracking tube at 850℃ using potassium acetate as coking inhibitor.Its inner surface and cokes deposited in the coking tests were characterized by scanning electron microscopy(SEM), field-emission scanning electron microscopy(FE-SEM), X-ray energy dispersion spectrometry(EDS), X-ray diffraction(XRD)and Raman spectroscopy.The results showed that the inner surface of the used 25Cr35Ni cracking tube was mainly composed of Cr1.3Fe0.7O3,FeCr2O4,Mn1.5Cr1.5O4, the intermetallic compound (Fe and Ni)and the needle-like deposition phase (intermetallic compound of Cr and Fe).Potassium acetate could inhibit coke formation effectively.When its concentration was 200 μg·g-1, deposition of coke was reduced by 51.54% in 1h.Potassium acetate did not change the length of coke filament, but it made filament diameter into nanometer level.The mechanism of inhibiting coking by potassium acetate was that gasification reaction between coke and water was catalyzed by alkali metal.The carbon in cokes deposited on the inner surface was of sp2 and sp3 bonds structure.Potassium acetate increased also graphitization degree of coke deposited.
    催化、动力学与反应器
    SO2-4-TiO2/MOR as novel solid acid catalyst for dehydration of fructose to 5-hydroxymethylfurfural
    <SHEN Xiang1, WEI Xiaorong1, WANG Yanxin2, QIAN Kun1, LI Rui1, HU Zhihai1
    2011, 62(12):  3411-3418. 
    Abstract ( 1419 )   PDF (951KB) ( 451 )  
    Related Articles | Metrics

    SO2-4-TiO2 catalysts are active for the hydrolysis of fructose, but they are deactivated in hot water in the next run. SO2-4-TiO2/MOR(STMsolid acid catalysts were successfully prepared to promote or stabilize SO2-4-TiO2 by using the sol-gel-hydrothermal new process.The activated natural mordenite (MORsupports had low costs, abundant microporous structure with high BET surface area, excellent thermal stability and easy recycling.As nanosized TiO2 could interact with the structural hydroxide of MORs, a binary STM catalyst was expected to be more acidic than either material alone.The binary mesoporous catalysts with high sulfate loading, high BET surface area and good dispersion showed better catalytic activities.The analysis results of pyridine molecular probe-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Ti2p, S2p and O1s peak fitting curves showed that loading and binding state of sulfur, interaction between active components and mordenite carriers made connection to distribution of Bronsted acid sites and Lewis acid sites.The 5-hydroxymethylfurfural (HMFyield and fructose conversion for STM0.2 catalyst reached 71.6% and 91.9% respectively.Recycling experiments showed that activities of STM0.2 catalysts decreased with increasing recycling times, the HMF yield declined to 44.5% in the third cycle.The Lewis acid sites of titanium dioxide helped to promote the conversion of fructose.Mordenite supports could improve the heat resistance of catalyst and the selectivity of target product.

    Catalytic degradation of dimethyl phthalate by photo-assisted Fe() immobilized collagen fiber
    <JIAO Limin1, 2, HUANG Xin2, LIAO Xuepin2, SHI Bi2
    2011, 62(12):  3419-3427. 
    Abstract ( 1172 )   PDF (1217KB) ( 167 )  
    Related Articles | Metrics

    Fe()immobilized collagen fiber(FeCFcatalyst was prepared and its photo-assisted catalytic degradation behaviors to dimethyl phthalate(DMPwere investigated.Compared with FeCF/ H2O2/dark, FeCF/UV and H2O2/UV reaction system, FeCF/ H2O2/UV is more effective for degradation of DMP.It is found that the H2O2 concentration and temperature are the main factors that greatly influence the degradation performance of DMP.Under irradiation of UV 254 nm, 100% degradation of DMP can be obtained within 30 min when the dosage of FeCF and H2O2 is 1.0 g·L-1 and 1.0 mmol·L-1 respectively.In addition, FeCF is effective for the degradation of DMP in the wide pH range of 3.07 to 7.96, and its photo-assisted catalytic degradation activity has no obvious decrease in 5 cycles.So, there is a potential for FeCF to treat DMP pollutant.

    A novel synthesis of adamantane polyhydric alcohols by direct oxidation of adamantane
    <’<,<,
    2011, 62(12):  3428-3433. 
    Abstract ( 1551 )   PDF (916KB) ( 970 )  
    Related Articles | Metrics

    Adamantane polyhydric alcohols are important active intermediates for synthesis of adamantane-based specific medicines, fine chemicals and functional materials.In this paper, three adamantane polyhydric alcohols, including adamantane-1,3-diol, adamantane-1,3,5-triol and adamantane-1,3,5,7-tetraol were synthesized via one-step oxidation reaction of adamantane by using Cr(Ⅵ)reagents as oxidants, acetic acid as solvent under the mild conditions.The structures of adamantane-1,3-diol, adamantane-1,3,5-triol and adamantane-1,3,5,7-tetraol were confirmed by IR, 1H NMR and element analysis.Influences of synthesis conditions on the oxidation reaction were investigated.The reaction mechanism of adamantane oxidation by Cr(Ⅵ)reagents was discussed as well.Under the optimum conditions, adamantane-1,3-diol, adamantane-1,3,5-triol and adamantane-1,3,5,7-tetraol could be synthesized with the yields of 71%, 42% and 35% respectively.Such synthesis technology for adamantane polyhydric alcohols is of potential for application because of brief reaction, convenient manipulation, and the mild conditions and so on.

    分离工程
    Characterization and Cu(Ⅱ)adsorption property of rice-husk-char-based porous silica with large specific surface area
  • <,<,
    2011, 62(12):  3434-3439. 
    Abstract ( 1231 )   PDF (444KB) ( 175 )  
    Related Articles | Metrics

    Porous silica with a large specific surface area (SSAwas prepared from rice husk char (RHCby adding H3PO4 to sodium silicate solution (SSSuntil the solution reached pH 4.1.The preparation process consisted of formation of SSS from RHC, that of silica-polyethylene glycol (PEGcomposite by using SSS, H3PO4 and PEG, and calcination of the composites.The porous silica as-prepared was characterized by N2 adsorption, X-ray fluorescence, X-ray energy dispersive spectrometer, X-ray diffraction, and Fourier transform infrared spectroscopy.Their characters for Cu(Ⅱ)adsorption were investigated by batch adsorption experiments.The results show that amorphous silica with specific surface area of 957 m2·g-1and silica content of 99.26% can be obtained from rice husk char within 10 h.The porous silica contains both micropores and mesopores, with the mesopore fraction up to 38.6%.The advisable contact time and solution pH for Cu(Ⅱ)adsorption required are higher than 2 h and 6.0, respectively.The largest adsorption capacity and highest removal efficiency for Cu(Ⅱ)at initial Cu(Ⅱ)

  • Effect of addition of alcohols on preparation of reverse osmosis composite membrane with high flux by interfacial polymerization
    <,<,<,
    2011, 62(12):  3440-3446. 
    Abstract ( 1333 )   PDF (1361KB) ( 1032 )  
    Related Articles | Metrics

    The effects of metaphenylene diamine (MPDand trimesoyl chloride (TMCconcentration on the performance of reverse osmosis (ROcomposite membranes were investigated.Different alcohols were added to the aqueous solution of MPD in order to improve the performance of as-prepared membranes.The maximal flux was found to be twice of the original flux.FTIR results suggest that the hydroxyl groups of alcohols reacted with TMC to form ester bonds and thus terminated the extension of polyamide molecular chains, and reduced the cross-linked degree of network structure, so that solute molecules are easy to penetrate through the membranes.The connection between membrane separation performance and solubility parameters of alcohols was investigated.When the solubility of alcohol is close to that of polyamide, the alcohol is easy to dissolve and penetrate in the nascent polyamide membrane, and therefore increases the reaction between the alcohol and TMC.The experiments exhibit that the addition of alcohols is an effective method for preparation of composite membrane with high flux. Under the optimum experimental conditions, the best mass fraction of additional alcohols in water phase is between 5% and 10% and as-prepared composite membranes exhibit high flux with a little sacrifice on rejection.

    过程系统工程
    Method of predicting equimolecular mixture of  ethylene cracking feedstock
    <,<,<,
    2011, 62(12):  3447-3451. 
    Abstract ( 1106 )   PDF (368KB) ( 100 )  
    Related Articles | Metrics

    The model of the petroleum hydrocarbon pyrolysis process based on free radical mechanism requires analyzing the detailed components of petroleum hydrocarbon.This paper integrated the molecular attributes in the petroleum hydrocarbon and the industrial indices of the petroleum hydrocarbon such as average molecular weight, H/C-ratio, the paraffin, isoparaffin, olefins, naphthenes, aromatics (PIONAmass fractions and a set of ASTM boiling points and the information entropy theory to predict the equimolecular mixture of the petroleum hydrocarbon.The method was applied in predicting the equimolecular mixture of naphtha and heavy vacuum gas oil.The calculated values of equimolecular mixture were in good agreement with the experiment data and the result proved that this method is effective.

    Simulation of aromatic extraction process based on regressed binary interaction parameters
    <WANG Lingyan,SUN Xiaoyan,LI Zhongjie,XIANG Shuguang
    2011, 62(12):  3452-3457. 
    Abstract ( 1320 )   PDF (361KB) ( 683 )  
    Related Articles | Metrics

    Because there were difficulties to obtain the accurate binary interaction parameters, it was hard to calculate the separation process correctly when sulfolane-aromatic extraction system was simulated.In this paper based on the process data of some aromatic extraction devices, the present equilibrium data of the components in the aromatic extraction system were found in the references firstly, so the binary interaction parameters between any component could be regressed and obtained.Some missing parameters were evaluated by regular solution theory.Secondly, the mathematical model of the primary equipment such as the extraction column and the rectifying column were established using the sequential modular approach to calculate the models.Compared the calculation results with the actual data,the results showed that the average relative error was below 5%, which indicates that the properties method and the mathematical models could calculate the aromatic process correctly and provide the actual production process with theoretical direction and technical support.

    Hot feed/discharge between plants with steam optimization
    <ZHANG Bingjian, WU Shengyuan, CHEN Qinglin
    2011, 62(12):  3458-3462. 
    Abstract ( 1279 )   PDF (966KB) ( 452 )  
    Related Articles | Metrics

    Heat of hot process streams is recovered to preheat cold streams, and some steam is generated simultaneously below pinch points to increase the efficiency of energy recovery.Hot feed/discharge between plants cannot only reduce the total utilities of up-plant and down-plant, but also increase steam generation by changing the pinch location and shape of grand composite curve (GCC).Composite curve of streams employed for hot feed/discharge and GCC are figured in a T-Q diagram, where the temperature of hot discharge is targeted by reversing and moving the composite curve of streams in horizontal direction, and the pressure and flowrate of steam generation are optimized by considering the energy requirement of steam in different pressure grade.An industrial example involving a vacuum residue hydrotreating plant (VRHPand a fluid catalytic cracking plant (FCCPis investigated to demonstrate the performance of presented model.The solution results indicate a decrease in the total utilities and an increase in the steam generation.

    表面与界面工程
    Performance of mechanical face seals with both surface micropores and convergent coning
    <,<,<’
    2011, 62(12):  3463-3470. 
    Abstract ( 1371 )   PDF (5926KB) ( 1778 )  
    Related Articles | Metrics

    Based on the study of mechanical face seals with convergent coning or surface micropores, a new type of mechanical seal with both surface micropores and convergent coning was presented.The definitions of face geometric parameters of such a new type of seal were made.Such parameters included the radial taper of the coned face, the width ratio of the coned face to the seal face, and the width ratio of sealing dam to seal face.A theoretical analysis model for controlling fluid film pressure between the two faces of such a seal was set up and was solved with the finite element method.The fluid film pressure profile between the faces was then obtained.Analyses were made about the effect of face geometric parameters on seal performance, such as opening force, leakage and axial film stiffness under low pressure or high pressure of the sealed medium, in which the radial length ratio of micropore zone to face width, circumferential arc length ratio of micropore zone to face circumference, and depth to diameter ratio of a micropore were kept constant.When such a seal was operated under low pressures of the sealed medium, the convergent taper would be beneficial to face opening behavior and the fan-type micropores sector located at the high pressure side of sealing face would be beneficial to sealing ability.When such a seal was operated under high pressures of the sealed medium, the hydrodynamic effect caused by micropores would be beneficial to sealing stability, and the fan-type micropores sector located at the low pressure side would be beneficial to sealing ability.Such a seal would show the best performance when the radial taper varied from 1.5 to 2.5, the width ratio of the conical face to the gross seal face varied from 0.2 to 0.6, and the width ratio of the inner sealing dam to the gross seal face varied from 0.1 to 0.3.

    能源和环境工程
    Effects of carbon sources on sludge settling and filamentous bacteria growth
    <<, ZHANG Leilei2
    2011, 62(12):  3471-3477. 
    Abstract ( 1378 )   PDF (2002KB) ( 840 )  
    Related Articles | Metrics

    The filamentous bulking of sludge is directly associated with specific influent characteristics and operational regime.In order to understand whether the types of carbon source can cause filamentous sludge bulking and lead to the formation of dominant filamentous bacteria, their long-term effects on sludge settleability and filaments growth as well as the competition between filaments and floc-formers were investigated.Three lab-scale sequencing batch reactors under controlled conditions were operated by using acetate, glucose and starch as carbon sources, respectively.When the storage capability of microorganisms was limited by decrease of substrate concentration gradient, there appears a great quantity reproduction of filamentous bacteria i.e.filamentous bulking (sludge volume index, SVI>600 ml·g-1for acetate- and glucose-fed systems.SVI was kept below 300 ml·g-1 for starch-fed reactor,although much open, fluffy and porous flocs were formed, and settling performance had no serious deterioration.The results from  staining reactions and fluorescent in situ hybridization showed that the first dominant filament was Thiothrix nivea for the acetate-fed reactor, S.natans for the glucose-fed reactor, N. limicola and M.parvicella for the starch-fed reactor.So, it was demonstrated that various carbon sources can lead to different metabolic characteristics for various substrates, and the occurrence of filamentous bulking was closely associated with kinetics and storage properties of microorganisms.

    Numerical simulation on performance of vanadium microfluidic fuel cell
    <GAO Mingfeng, ZUO Chuncheng, ZHANG Zhou
    2011, 62(12):  3478-3483. 
    Abstract ( 1586 )   PDF (798KB) ( 754 )  
    Related Articles | Metrics

    In this study, a theoretical analysis for a novel microfluidic vanadium fuel cell was implemented, which relies on laminar flow at low Reynolds number to maintain sufficient separation of fuel and oxidant streams.A three-dimensional numerical model that accounts for laminar flow, transport process of species and electrochemical reactions in fuel cell, was developed to evaluate the effect of some important physical factors including volumetric flow rate and fuel purity.All coupled equations in the model were solved digitally together.The simulation results showed that output power and current density went up with the increase of flow rate, however, the fuel utilization went down significantly.As the volumetric flow rate increased from 1 μl·s-1 to 25 μl·s-1, the power density increased by 2.2 times and there was a 90% drop in fuel utilization.Further microfluidic fuel cell design and optimizations were guided by using the model, a double Y-shaped microchannel design is proposed.It is found that the fuel utilization can be improved significantly by using a double Y-shaped microchannel.

    Coal gasification performance in fluidized bed-entrained flow integrated reactor
    <CHEN Xiaohui1, JIA Yalong1, FENG Jie1, FANG Yitian2, LI Wenying1
    2011, 62(12):  3484-3491. 
    Abstract ( 1378 )   PDF (1050KB) ( 623 )  
    Related Articles | Metrics

    The carbon conversion from the fluidized bed coal gasification is about 85%.The fluidized bed-entrained flow integrated coal gasifier was built with the aim to reuse the carbon in fly ash.A reactor network model was established by using the software CHEMKIN to study the reactions occurring in the integrated gasifier, and to investigate carbon re-gasification in fly ash.Based on experimental results on a 300 mm (i.d.) integrated gasifier, the raw materials inter-phase flow, mass and heat transfer in different zones and the hydrodynamic characteristics of the integrated coal gasifier were analyzed.This model is to simplify the unstable continuity process in the integrated gasifier into a combination of ideal reactors, attempting to avoid the non-convergence of the study on complex flow field with many reactions with the CFD model.This model could be significant in the accurate analysis of new reactor concepts with sufficient knowledge of the hydrodynamic characteristics of reactors.Through the model, the carbon conversion rate of fly ash in the integrated coal gasifier, temperature profile and residence time of materials were recorded and calculated respectively. It was concluded that carbon conversion rate of fly ash reached 64.1% in the entrained flow, and that the carbon in fly ash with low reactivity was re-gasified.Accordingly, the carbon conversion in the whole gasification system increased from 84.9% in the fluidized bed reactor to 92.2% in the integrated coal gasifier.

    Effect of sludge type on sludge alkaline fermentation
    SU Gaoqiang, PENG Yongzhen, WANG Chuanxin, GAO Yongqing, HUO Mingxin, ZHU Suiyi
    2011, 62(12):  3492-3497. 
    Abstract ( 1950 )   PDF (451KB) ( 710 )  
    Related Articles | Metrics

    There are mainly three types of sludge in the wastewater treatment plant, i.e., waste activated sludgeWAS, primary sludgePS and mixed sludgeMS, for which their composition is different, leading to different products of fermentation.So, in this paper their anaerobic fermentation characteristics was investigated under the condition of 35, pH= 10 and the same concentration of VSS (volatile suspend solids).The results showed that there was a sludge order for both the soluble chemical oxygen demand (SCODand total volatile fatty acids (TVFAproducedWAS>MS>PS.The optimal fermentation time for all type of sludge was 8 d, and producing TVFA 529能源和环境工程

    Thermal economics and application of pressurized submerged  combustion evaporators
    <JIANG Han, LIU Zhongliang, GONG Xiaolong
    2011, 62(12):  3498-3502. 
    Abstract ( 1555 )   PDF (487KB) ( 476 )  
    Related Articles | Metrics

    Compared with conventional steam boilers, slightly-pressurized submerged combustion evaporator is advantageous, which is in the absence of a heat transfer surface, with higher efficiency of heat transfer and lower emission of pollutants.Pressurized submerged combustion evaporator (PSCEreported in this paper is its extension to high pressures and temperatures.Based on the first law of thermodynamics and with the consideration of energy consumption of compressors in PSCE and fans in steam boiler, the PSCE is compared with the steam injection boiler under the same condition.For 821 MPa steam, although the energy consumption of compressors constitutes a large proportion of the whole energy consumption in PSCE, the heating efficiency is high and the heat recovery of PSCE is effective.The energy saving rate of PSCE is estimated, which is usually 6%12%.The results show that PSCE has a greater potential for energy saving than steam boiler.

    Factors affecting microbial fouling formation in simulated  recirculating cooling-water system
    <,
    2011, 62(12):  3503-3510. 
    Abstract ( 1893 )   PDF (516KB) ( 795 )  
    Related Articles | Metrics

    A slime-forming bacterial strain N1 was isolated and purified from the Songhua River.According to the morphological observation as well as the physiological and biochemical indexes, the strain was identified as Micrococcus.Under certain experimental condition (water temperature 30, flow velocity 0.4 m·s-1 and microorganism concentration between 7.0×106 cfu·ml-1 and 2.2×1010 cfu·ml-1), the fouling resistance was monitored online in an experimental device for dynamic simulation of forming fouling, and the heat transfer characteristics were analyzed.The induction period of microbial fouling in the stainless steel tube was about 57 h, which was shorter than that in the copper tube.In the contrast experiment with converging-diverging tube, it was found that flow velocity had certain influence on the formation of microbial fouling.The change of flow velocity could prolong the induction period of microbial fouling.During the dynamic experiment, many water quality parameters including pH, conductivity, total bacterial count, total nitrogen and COD were detected periodically.Based on the grey relational algorithm, the correlation for water quality parameters and microbial fouling was analyzed, which provides a theoretical basis for predicting the microbial fouling and selecting the effective measures for scale removal.

    Nitrification performance of wild halophilic mixed culture in treating highly saline domestic wastewater
    <,<,
  • <,<,
    2011, 62(12):  3511-3517. 
    Abstract ( 1260 )   PDF (450KB) ( 706 )  
    Related Articles | Metrics

    Due to effects of high osmotic pressure and biological toxicity of inorganic salts, eubolism of activated sludge developing in fresh wastewater can not be carried out in highly saline wastewater.This difficulty could be solved by collecting, studying and culturing halophilic activated sludge from the estuary deposit at the mouth of the river.In this paper the effect of start-up, ammonium-nitrogen loading and salinity on nitrification performance of the halophilic nitrification culture in treating real saline domestic wastewater was studied.The results show that after 9 day adjustment stage, nitrification of ammonium-nitrogen is started.This halophilic system is sensitive to ammonium-nitrogen loading and its fluctuation.Salt tolerance of 1060 g·L-1as well as optimum salt of about 40 g·L-1 was established.Comparing with fresh activated sludge and salt-acclimation activated sludge, this system is of advantages of high specific ammonium removal rate and tolerance of salt shocks, because the dominant population is composed by moderately halophilic and marine bacteria.JP2A noteworthy is that there is unusually high nitrite accumulation rate during experimental operation although all operation conditions are very preferable to nitrite oxidation.The research can provide an alternative way for application of the halophilic mixed culture in biological treatment of highly saline wastewater.

  • Distribution and transformation regularity of pharmaceutical pollutants in a Xian sewage treatment works
    <ZHANG Aitao, BO Longli, LI Xuegang, FU Jinting,LI Ping, WANG Xiaochang
    2011, 62(12):  3518-3524. 
    Abstract ( 1814 )   PDF (559KB) ( 251 )  
    Related Articles | Metrics

    Based on stationing monitoring and sampling analysis for a Xian sewage treatment works operating with A2/O process and medium loading process, the distribution and transformation regularity of pharmaceutical pollutants were studied.The results showed that there were six typical pharmaceuticals, Phenacetin, Gemfibrozil, Caffeine, Aminopyrine, Clofibrate acid and Diclofenac acids in flooding water at the concentrations of 14.98 μg·L-1, 0.64 μg·L-1, 19.36 μg·L-1, 2.15 μg·L-1, 0.95 μg

    Analysis on accumulation, distribution and origin of polycyclic aromatic hydrocarbons in soils under a coking plant
    <,<,<,<,<,<,
    2011, 62(12):  3525-3531. 
    Abstract ( 1286 )   PDF (557KB) ( 510 )  
    Related Articles | Metrics

    Anthropogenic polycyclic aromatic hydrocarbons (PAHsare one of the most major pollutants in soil under coking plants.In order to understand the characteristics of accumulation and vertical distribution of 16 USEPA priority PAHs in soil, GC/MS was used to analyze 16 PAHs in 587 soil samples taken from different depths of 018 m under coking plant.The results showed that, the highest and average concentration of total PAHs were 14363.7 mg·kg-1 and 190.4 mg·kg-1 respectively, indicating that the soil under coking plant had been polluted.The dominant components were low molecular weight PAHs, accounting for about 85%.The concentrations of PAHs had obvious fluctuation at various layers, and their concentration change was parallel.There was an obvious cumulative effect in 56 m soil layer, which might be due to different filtration capability of soil in different layers and PAHs leaching ability.Based on the principal component and Q-clustering analysis, the entire soil profile could be classified into 5 different layers01 m, 13 m, 35 m, 5

    Analysis of microbial community structure in enhanced biological dephosphorization
  • <<,TIAN Wende1,KANG Xiaorong1, ZHANG Hui1, GUO Xuan1
  • 2011, 62(12):  3532-3538. 
    Abstract ( 1288 )   PDF (618KB) ( 435 )  
    Related Articles | Metrics

    In order to study the microbial community structure and diversity as well as the performance of phosphorus removal associated with microbial community change, the fingerprint profile technique of PCR amplified 16S rRNA and denaturing gradient gel electrophoresis (DGGEwere applied to analyse the microbial communities in Bi-Bio-Selective simultaneous Phosphorus and Nitrogen removal (BBSPNprocess.After the characteristic bands eluted from gel were further recovered, cloned (reamplifiedand sequenced, the sequences were compared with those in GenBank database and used for homology analysis, and the phylogenetic trees were constructed.The sequence of DGGE bands obtained showed that there is a good dynamic correlation between microbial community variation and its removal performance of process.TP removal efficiency of BBSPN process was lower when α-proteobacteria was the dominant species, which mean α-proteobacteria was not favorable for enhanced biological phosphorus removal; whereas when Bacteroidetes was the dominant species, TP removal efficiency and denitrifying dephosphorization were better and stable, which should attribute to Uncultured Sphingobacteriaceae.So, the Uncultured Sphingobacteriaceae was like to be one of the denitrifying phosphate accumulating organisms(DPAOsin this process.Moreover, Acinetobacter,TM7 and Uncultured Trichococcus are also beneficial for phosphorus and nitrogen removal of BBSNP process.

    材料化学工程与纳米技术
    Water absorbency properties of chitosan-g-poly(acrylic acid sodium)/kaolin superabsorbent composite
    <,
    2011, 62(12):  3539-3544. 
    Abstract ( 1860 )   PDF (438KB) ( 689 )  
    Related Articles | Metrics

    Increasing global demand for improved absorbent materials with biodegradablenon-toxic, antimicrobial, and salt-tolerant properties creates an incentive for research and development of efficient absorbent materials and systems with additional benefits, such as biodegradability or certain biomedical functions.Organic-inorganic superabsorbent composite emerges to meet this demand.Chitosan grafted poly(acrylic acid sodium)/kaolin superabsorbent composite was prepared by solution polymerization in this paper.The absorption rate and repeated absorption properties in distilled water, water absorbency in artificial urine solution, and the influence at different temperatures, electrolyte concentrations and pH values on absorbency properties of the superabsorbent composite were discussed, respectively.The results showed that absorption rate of superabsorbent composite was slower than that of polyacrylic resin and chitosan grafted polyarylic resin and water absorbency decreased with increasing repeat number, and water absorbency in artificial urine solution was higher than poly(acrylic acidand lower than chitosan grafted poly(acrylic acid).As temperature increased, water absorbency was enhanced, while began to drop after 50.Water absorbency of superabsorbent composite decreased simultaneously when ionic strength and valence of electrolyte solution increased.Along with the increase of pH valuethe absorption curve showed a hump at pH=3.5 and pH=8.5.According to this study, basic information of absorbency properties about organic-inorganic superabsorbent composite based on chitosanpoly(acrylic acidand kaolin was provided.

    Lattice Boltzmann simulation for impregnation of LWRT
    <,<,
    2011, 62(12):  3545-3553. 
    Abstract ( 1187 )   PDF (1842KB) ( 390 )  
    Related Articles | Metrics

    The lattice Boltzmann method at representative elementary volume (REVscale was used to simulate transverse impregnation for LWRT (light-weight reinforced thermoplastic), and it offers a new method for the prediction of impregnation velocity and time.The effects of press manner, loading, temperature and the structure of the double-belt press on impregnation were investigated.The results showed that the double-belt press was more effective in shortening impregnation time compared with the flat press owing to its alternating high/low pressure distribution.Besides, it was found that impregnation was determined by not only the maximum impregnation velocity but also the residence time under high pressure.The maximum impregnation velocity could be improved by enhancing loading and increasing temperature as well.The residence time was more sensitive to the diameter of the roller of double-belt press and loading.However, it was impossible to shorten the impregnation time only by adjusting the processing velocity of the belt.

    Synthesis of dipropargyl ether of bisphenol A and thermal degradation kinetics of its polymer
    <YANG Zhaopan, SHI Tiejun, TAN Dexin
    2011, 62(12):  3554-3559. 
    Abstract ( 1617 )   PDF (506KB) ( 588 )  
    Related Articles | Metrics

    Dipropargyl ether of bisphenol A was synthesized by using phase transfer catalyst and was characterized by FT-IR1H NMR and 13C NMR.A polymer of dipropargyl ether of bisphenol A was prepared.TG and DTG were used to study the thermal degradation kinetics of the polymer in N2.The kinetic parameters were calculated by methods of Kissinger and Ozawa.The results showed that the apparent degradation reaction order of the polymer of dipropargyl ether of bisphenol A was 1 in N2 via the Coats-Redfern method.Thermal degradation activation energies of the polymer were 166.36 kJ·mol-1 and 199.90 kJ·mol-1 by methods of Kissinger and Ozawa respectively.The temperature of 60 s lifetime was 461 in N2.

    Preparation of microbial transglutaminase-induced soybean glycinin transparent cold-set hydrogels
    <ZHANG Ye, GUO Jian, YANG Xiaoquan, YIN Shouwei, QI Junru
    2011, 62(12):  3560-3568. 
    Abstract ( 1140 )   PDF (2185KB) ( 476 )  
    Related Articles | Metrics

    A novel method of preparing transparent cold-set hydrogels by soybean glycinin (11Swas developed.Addition of dextran sulphate (DSto soybean glycinin (11Sin the first step induced the 11S/DS solution to form soluble complexes with higher negatively charged, which had a significant effect on improving transmittance after the preheat process.Cross-linking with microbial transglutaminase (MTGasewas used in the second step, and transparent gels were formed by ε-(γ-glutamyllysine isopeptide bonds at pH 7.0 with low ionic strength.The result indicated that transparency markedly increased at DS/11S (mass ratioof 0.005 or more and decreased when NaCl was involved and much better hardness was achieved by covalent bond crosslinked with MTGase.Scanning electron microscopy showed finer and more intensive networks of gels were formed by addition of DS.Water holding capacity (WHCincreased when more DS was added.The combined effects of DS concentration and ionic strength influenced the rheological properties, and determined texture properties of gels.The inhibitory effect of DS would be ascribed to the formation of firmer and transparent soybean glycinin gels with better characteristics.

    Effect of styrene-sodium acrylate ionomer/poly(ethylene glycolon crystallization behavior of PET
    <,<,
    2011, 62(12):  3569-3574. 
    Abstract ( 1287 )   PDF (691KB) ( 179 )  
    Related Articles | Metrics

    The crystallization of PET modified by the mixture of styrene-sodium acrylate ionomer (SAA-Naand poly(ethylene glycol)(PEGwas investigated by differential scanning calorimeter(DSC).With the addition of 5%mass PEG, cold-crystallization temperature (Tccand glass transition temperature (Tgof PET decreased significantly.Compared with PET/SAA-Na, the crystallization of PET/mixture (1%SAA-Na and 5%PEGwas further enhanced,melt-crystallization temperature (Tmcincreased from 212.8 to 216.1

    Effect of crystallization additives on crystal morphology of ammonium sulfate
    <<, ZHANG Yi1,2<<, WANG Jingkang3, CHEN Wei3, XU Hongbin1,2
    2011, 62(12):  3575-3579. 
    Abstract ( 1405 )   PDF (779KB) ( 800 )  
    Related Articles | Metrics

    A series of additives were introduced to crystallization process of ammonium sulfate, and different forms of ammonium sulfate crystal were obtained.The crystallization process was studied based on experiments and computer simulation.The effect of crystallization additives on morphology of ammonium sulfate was investigated.The ammonium sulfate crystals were characterized by XRD and SEM analysis to examine crystal habit and crystal form.Materials Studio is employed to calculate molecule binding energies between additive ions and ammonium sulfate crystal surfaces.The results indicate that the values of binding energy have certain relationship with growth rates of crystal faces, which illustrates the effects of impurities and additive ions on crystal habit of ammonium sulfate.Molecule binding energy of cationic additives is higher than that of molecules.The higher valence of cationic additive is, the higher molecule binding energy is.Based on the kinetic data and molecular simulation results, the effect mechanism of different impurities on crystallization is analyzed.

    Preparation of precipitated silica from desilicated solution of high-alumina fly ash by dissolution with alkaliexperiment and principle of polymerization of silicic acid
  • <<, MA Hongwen1, LIU Hao2, ZOU Dan2
  • 2011, 62(12):  3580-3587. 
    Abstract ( 1275 )   PDF (469KB) ( 111 )  
    Related Articles | Metrics

    In this paper, high-alumina fly ash from a thermal-electric plant of Shaanxi Province was used as raw material,and was treated with alkali to prepare desilicated solution, which was then carbonated to prepare precipitated silica.During orthogonal experiments and single-factor experiments, the optimal carbonation conditions were determined as follows, under 100 r·min-1 peed stirring, 500 ml·min-1 CO2 flow rate, sodium metasilicate concentration 17.8°Bé, and at reaction temperature around 85, reaction time around 2.5 h.The white carbon black product (BTH-01was prepared from silica gel through drying at 105 overnight.The product (BTH-01satisfied the type A standard of white carbon black GB1051789. The carbonation reaction process was analyzed.Nuclear magnetic resonance measurement method was used to trace the processing path of silica gel, which could better describe the SiO conjugation during different times in carbonation.The technology provides some guidance to analyzing the structure of white carbon black.

    Non-isothermal crystallization kinetics and mechanical properties of olybutylene terephthalate/polycarbonate blends modified by toughening agent
    2011, 62(12):  3588-3594. 
    Abstract ( 1552 )   PDF (927KB) ( 1824 )  
    Related Articles | Metrics

    The polybutylene terephthalate (PBT/ polycarbonate (PCblends modified by toughening agentS-2001consisting of methyl methacrylate, styrene and silicone were prepared via melt blending.The non-isothermal crystallization kinetics of the blends were investigated by scanning calorimetry (DSCat different cooling rate of 5℃·min-110℃·min-115℃·min-1, and the data were analyzed by using modified Avrami theories of the Jeziorny method.The influence of toughening agent其他

    Source identification of combustion soot generated by different petroleum chemicals fuels
    <ZHI Youran1,2,ZONG Ruowen1,2,ZENG Wenru1,REN Xiaonan1,TAN Jialei3
    2011, 62(12):  3595-3600. 
    Abstract ( 1154 )   PDF (899KB) ( 646 )  
    Related Articles | Metrics

    The SPME-GC-MS method is applied to analyze the characteristic components of combustion soot generated by four kinds of petroleum chemicals fuels i. e.the gasoline, the diesel, the polystyrene and the ABS (acrylonitrile butadiene styrene).The spectrums of these four different combustion soot and the corresponding characteristic components are obtained by this method.Based on the retention time and the corresponding characteristic components summarized from the spectrums of the four kinds of combustion soot, a 20 × 35 mathematic matrix is obtained.The PCA method is applied to analyze this matrix and in succession three main principal components are summarized, with the cumulative rate up to 92%, which indicates that the two or three dimensional coordinate system composed of the principal components is quite effective to classify the combustion soot of different fuels.Finally, based on the results of PCA,an advanced pattern recognition method i. e.the HCA is applied to classify the four types of combustion soot with 100% accuracy.