Table of Content

20 April 2009, Volume 9 Issue 2

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流动与传递

Fluidization Properties in Microscale Fluidized Beds

XU Yi-quan GUO Qing-jie SI Chong-dian CAO Chang-qing

. 2009, 9(2):  209-215. 

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The fluidization characteristics of quartz sand and FCC catalyst particles in 6 microscale fluidized beds with inner diameters of 4.3, 5.5, 10.5, 15.5, 20.5 and 25.5 mm were investigated. The influences of bed diameter (Dt), static bed height (Hs), particles and gas properties on the pressure drop and minimum fluidization velocity (umf) were examined. The results show that the theoretical pressure drops of microscale fluidized beds deviated from the experimental values under different particles and gas properties. The pressure drop correlations for large size fluidized beds failed to compute microscale fluidized beds. umf increased with decreasing Dt. When the ratio of Hs to Dt ranged from 1 to 3, umf was expressed by linear relationship with Hs, while the slope of equation of umf versus Hs decreased with the increase of Dt. Dt/dp and Hs/dp were defined as dimensionless variables, a new equation was developed to predict umf under the present experimental conditions.

Mixing and Segregation of Binary Mixture in a Vibration Fluidized Bed

LIU Chuan-ping WANG Li JIA Min

. 2009, 9(2):  216-221. 

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Putting the mixture of 2 mm and 4 mm zeolite particles in a 2D vibration fluidized bed with the size of 300 mm′300 mm′20 mm, the effects of influential factors including vibration intensity and gas velocity on the distribution of particles were studied at u

Signal Quality of Dual-tip Electrical Conductivity Probe for Measurement of Bubble Parameters

HAN Mei SHA Zuo-liang WU Qian WANG Tie-feng WANG Tie-feng WANG Jin-fu

. 2009, 9(2):  222-227. 

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A dual-tip conductivity probe for measurement of bubble parameters in a gas-liquid flow was studied. The effects of the probe structure, measurement circuit and sampling method on the bubble signal quality measured with the probe were investigated, and the measures to improve the signal quality were proposed. The experimental results show that the signal response is faster when the conductive length of probe tips is smaller. This effect becomes insignificant when conductive length is smaller than 0.025 mm. The probe tip should be connected to the cathode of measurement circuit to avoid the electrical oxidation corrosion that caused damage of the probe tip. The better bubble signal response is obtained by using optimum electrical resistance in the measurement circuit with smaller electrical resistance of the probe tip. The improved signals with large difference of 3 V, fast response and little noise are obtained with the optimal conditions.

Determination of Raceway Boundary with Particle Velocity Contour

LUO Zhi-guo SUN Ye LIU Hong-hua ZOU Zong-shu

. 2009, 9(2):  228-232. 

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A new method has been developed to determine the raceway boundary in cold model of COREX melter gasifier, so as in blast furnace, granular drying, etc. The particle velocity contour criterion of raceway boundary definition is 0.15 m/s, and the precise raceway boundary can be obtained through this method. It is very important for the theoretical and mathematical modeling of gas and solid flow and chemical reaction in and around the raceway region.

Transient Coupled Numerical Simulation of Solidification Process of Slab Continuous Casting

JIN Xue-wei WANG Chang-song ZHANG Yu-bao XUE Jian-guo PEI Hong-xing CAO Jun-min

. 2009, 9(2):  233-237. 

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Based on the data obtained from actual solidification process of slab casting, a 3-D coupled model for describing flow field, temperature field and solidification of slab casting process was simulated with the continuum transient model. The results showed that the fluid flowed from the outlet of submerged entrance nozzle forming top and down recirculations in the mold zone, solidification promoted the decay of turbulent fluid flow speed and the region of recirculation was enlarged along with the casting speed increasing. Local overheat was found at the position of 100~150 mm from the corner of slab in the mold wide zone. About 3 mm decrease in the thickness of solidified shell was calculated by increasing the speed from 0.02 m/s to 0.025 m/s at the mold outlet.

Liquid Flooding of a Rotating Zigzag High-gravity Bed

XIE Ai-yong LI Yu-min XU Zhi-chao WANG Hong-jun JI Jian-bing

. 2009, 9(2):  238-241. 

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The flooding correlation of high-gravity rotating zigzag bed (RZB) was established on the basis of a correlation of flooding in counter-current two-phase flow in tubes proposed by Wallis. The experiment was carried out in a RZB with rotor diameter of 288 mm and rotor height of 55 mm in air-water system. The rotor had two types of structure (single-row orifices and multi-row orifices) on the rotational disc. A flooding correlation was obtained by regression based on the experimental data. The results showed that the flooding capacity factor decreased with the increase of gas-liquid flow rates. The factor was reduced by 0.007 m/s when rotational speed increased each time by 100 r/min. And the factor by the rotor with multi-row orifices was 8.5% greater than that of single-row orifices.

反应与分离

Separation, Purification and Characterization of Three Endo-polygalacturonases from a Newly Isolated Penicillum oxalicum

ZHANG Chun-hui LI Zu-ming PENG Xia-wei JIA Yue ZHANG Hong-xun BAI Zhi-hui

. 2009, 9(2):  242-249. 

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Three endo-polygalacturonases (endoPGs) from a newly isolated Penicillum oxalicum (CGMCC 0907) capable of utilizing waste biomass as growth substrate were separated and purified to homogeneity by ultra-filtration, affinity adsorption chromatography, CM-cellulose column chromatography, and Sephadex G-100 gel filtration chromatography with the overall yield of 64.5% from the crude enzyme. The specific activities and recovery rates of endoPG-1, endoPG-2 and endoPG-3 were 1120 U/mg and 21.6%, 1350 U/mg and 25.9%, and 1560 U/mg and 17.0%, respectively. The three purified endoPGs had a close molecular weight to 41 kDa as estimated by SDS-PAGE. The optimum temperature and pH for the function of them were 65℃ and 5.0, 55℃ and 5.0, 50℃ and 5.5, respectively. Their pI and Km values were 5.9 and 0.78 mg/mL, 6.0 and 1.2 mg/mL, and 6.1 and 2.0 mg/mL, respectively.

Removal of As(V) from Drinking Water by Activated Carbon Loaded with Fe(III) Adsorbent

YAO Shu-hua JIA Yong-feng WANG Guo-qing SHI Zhong-liang

. 2009, 9(2):  250-256. 

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An effective adsorbent for removal of arsenate from aqueous system was synthesized by loading ferrihydrite on activated carbon. The effects of carbon types, particle size, solution pH, Fe(III) concentration and competing anions on removal rate of arsenate were studied. The results showed that coal-based activated carbon loaded with ferrihydrite had better arsenate removal efficiency than those of coconut- and husk-based activated carbon. The removal efficiency of As(V) increased significantly with decreasing the particle size of activated carbon. Arsenate was effectively adsorbed by activated carbon loaded with ferrihydrite in the pH range of 3~9. The addition of F-, Cl- and SO42- showed negligible effect on arsenate removal, but PO43- and SiO32- had large effect. The pattern of adsorption of arsenate ion with composite adsorbent better matched with Langmuir model than Freundlich model. The adsorption reaction between arsenate and the binding surfaces could be described by a second order rate equation.

Leaching of Nickel-Molybdenum Sulfide Ore with Sulfolobus metallicus

CHEN Jia-wu GAO Cong-jie ZHANG Qi-xiu XIAO Lian-sheng ZHANG Gui-qing

. 2009, 9(2):  257-263. 

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The bioleaching of nickel-molybdenum sulfide ore with thermophilic and acidophilic lithotrph, Sulfolobus metallicus, with shaking flasks was studied. The result shows that the leaching rate of Ni with Sulfolobus metallicus was all more than 90%, but that in the groups without Sulfolobus metallicus was 77.64%. The leaching rates of Ni and Mo in the groups with tamed Sulfolobus metallicus were 94.7% and 70.2% respectively, and those in groups with untamed Sulfolobus metallicus 93.1% and 68.4%. The leaching rates of Ni and Mo in the groups at pH 2 were 100% and 66.97% respectively. All of Ni in the groups with the sizes under -0.048 mm and -0.077 mm was leached out, while the leaching rates of Mo were 68.4% and 64.5%. The leaching rates of Ni and Mo in the groups at 5 g/L ore content were 100% and 87.29% respectively. In the groups with Fe3+ 0.5 g/L added and contrast group without Sulfolobus metallicus, the leaching rates of Ni were respectively 92.8% and 76.6%, and Mo 52.56% and 49.34%. The leaching rates of Ni and Mo in the groups with Sulfolobus metallicus were 93.17% and 73.52% respectively, while just 67.34% of Ni and 38.36% of Mo were leached out in the groups with Thiobacillus ferrooxidans.

Leaching of Valuable Metals from Roasted Residue of Spent Lithium-ion Batteries with Ammonium Sulfate

LI Dun-fang WANG Chen-yan YIN Fei CHENG Yong-qiang JIE Xiao-wu YANG Yong-qiang WANG Jun

. 2009, 9(2):  264-268. 

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Spent lithium-ion batteries (LIBs) blended with ammonium sulfate were roasted at elevated temperature. The effects of pH value of sulfuric acid leaching solution, roasting temperature and amount of ammonium sulfate on leaching rates of metal elements were investigated. Roasted residue was also leached with a mixed solution containing ammonia and ammonium sulfate. The results showed that all of lithium could be leached out. Due to the metallic copper in the roasting residue, the leaching rate of copper only reached 92.86% in sulfuric acid solution, but could be up to 97.60% in ammoniacal solution. Under the experimental conditions, the leaching rate was lower than 68% for cobalt because of undissolved Co3O4 in the roasted residue. The leaching rate of total cobalt was more than 99% when high concentration sulfuric acid with volume ratio of sulfuric acid to water at 1:2 was employed to treat the above leached residue.

Extractive Distillation of Ethanol-Cyclohexane Azeotrope Using Ionic Liquid as Extractant

WANG Xiao-ke TIAN Mi

. 2009, 9(2):  269-273. 

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The effect of different ionic liquids on relative volatility of ethanol-cyclohexane system was examined at 0.101 MPa. The effects of solvent ratio on relative volatility of ethanol-cyclohexane system, and flow rate of ionic liquid and reflux ratio on purity and output of overhead fraction of the extractive distillation column with ionic liquid were studied. Repeated experiments were carried out under the optimum experimental conditions. The results show that the azeotropic point of ethanol-cyclohexane system is eliminated in extractive distillation with ionic liquid and relative volatility of cyclohexane to ethanol increases. The purity of cyclohexane is over 99.8% when [bmim]PF6 is used as extractant, solvent ratio 0.5, flow rate of ionic liquid 6 mL/min and reflux ratio 3. By flash distillation of residue, ethanol and ionic liquid can be separated. The recovery rate of ethanol is over 99.9% and the recycled usage of ionic liquid does not impair the separation performance.

Adsorption Behavior and Mechanism of Aniline on Rice Bran

LI Fang-chen DAI You-zhi LUO Yue-ping YOU Zhi-min

. 2009, 9(2):  274-278. 

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The effects of particle size, biosorbent dosage, pH and temperature on biosorption capacity were studied with static experiments, and the adsorption process was analyzed in thermodynamics and kinetics, and the adsorption mechanism analyzed by infrared spectroscopy. The results showed that in the studied condition range, the initial adsorption rate increased with decrease in the rice bran particle size and increased with increasing temperature. Acidic conditions were conducive to adsorption. At 303 K and in neutral environment, the saturation adsorption qmax was up to 1.34 mg/g. The equilibrium data fit well with the Langmuir isotherm, and the thermodynamic parameters indicated that the adsorption reaction was endothermic and spontaneous. The pseudo-second-order equation provided the best correlation for the adsorption process, being in agreement with chemical adsorption as the rate controlling step, and there was a certain amount of hydrogen bonding adsorption.

Effects of Span-20 and Tween-80 on Foam Fractionation Behavior of Nisin in Fermentation Broth

LI Xin-tao WU Zhao-liang; ZHAO Yan-li; WU Ya-ming

. 2009, 9(2):  279-283. 

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The effects of Tween-80 and Span-20 on foam fractionation of Nisin (a food additive) fermentation broth were studied by using a single foam column. The results indicated that bubble size distribution, foam height and average gas holdup of the foam layer of the mixed system containing Tween-80 and Span-20 changed obviously from Nisin fermentation broth. The bubble size order of different mixed systems was: fermentation broth containing 0.2 g/L Span-20>fermentation broth containing 0.5 g/L Span-20>fermentation broth>fermentation broth containing 0.2 g/L Tween-80>fermentation broth containing 0.5 g/L Tween-80. The addition of surfactants decreased the height of foam layer and gas holdup, but Tween-80 increased the foam stability. And Tween-80 reduced the denaturation rate of Nisin in foam fractionation, so the separation effect was improved distinctly.

Migration and Precipitation Behavior of Fe Components in Copper Smelting Slag

CAO Hong-yang FU Nian-xin ZHANG Li XIA Feng-shen SUI Zhi-tong FENG Nai-xiang

. 2009, 9(2):  284-288. 

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The migration and precipitation of Fe components in the copper slag from a copper smelter were studied by a high temperature oxidation method. The effects of oxygen flow rate, time and temperature on the migration and precipitation were systematically examined. Phase composition and morphology of the modified slag were examined with XRD and SEM, and the grain size and volume fraction of magnetite phase measured. The results showed that the migration, enrichment, precipitation and growth of Fe components in the slag could be improved by prolonging oxidation time and increasing oxygen flow rate and temperature. The optimal conditions were obtained as modification temperature at 1653 K, oxygen flow rate 7 L/min and oxidation time 6 min, so the grain size could be increased from 20 to 80 mm, and the volume fraction from 20% to 50%, the iron concentrate of 54%(w) Fe at 90% recovery rate could be obtained by magnetic separation process.

Recovery of Vanadium by Nanofiltration from the Leaching Solution of Stone Coal Roasted with Sodium Chloride

WANG Xue-wen LIU Wan-li ZHANG Gui-qing WANG Ming-yu HU Jian

. 2009, 9(2):  289-292. 

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The leaching solution of stone coal roasted with sodium chloride was used to study the effects of pH value, operation pressure and vanadium concentration on vanadium recovery with nanofiltration, and the behavior of Cl- in nanofiltration process was also examined. The results show that for the nanofiltration, under the optimal condition of operation pressure at 10.0~12.5 kg/cm2 and pH value at 5.16~6.15, the concentration of vanadium measured as V2O5 in the solution can be concentrated to above 35 g/L. The rejection rate of vanadium increases with pH from 3.16 to 6.15, and the peak rate of 92% is reached at pH 6.15. NH4VO3 was precipitated in the rejected solution by adding NH4Cl in the stoichiometric proportion of 2.2. The product V2O5 with purity 98.6% was obtained by thermal decomposition of the precipitated NH4VO3 at 500℃ for 1 h.

过程与工艺

Coating Uniformity of Ni/C Composite Particles

CHEN Ye LIU Wei; DU Ling-zhong ZHANG Wei-gang

. 2009, 9(2):  293-299. 

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The influences of dispersivity of core particles and mass transfer of hydrogen on coating uniformity of spherical Ni/C composite particles in high pressure hydrogen reduction process were studied. The results showed that the thickness of nickel coating varied form 4.5 to 6.0 mm while the diameter of spherical graphite particles from 30 to 60 mm. Decreasing the size distribution of graphite particles could decrease the variation of coating thickness and improve the coating uniformity of Ni/C composite. Agitation with double blades was superior to single blade in the range of 500~1000 r/min stirring speeds. By using double blades, the mass transfer of hydrogen in the reaction system was effectively enhanced and the coating uniformity of obtained Ni/C composite obviously improved.

Preparation and Characterization of Al(OH)3 Coarse Particles by Decomposition of Caustic Aluminate Solution with Methanol

ZHANG Ying ZHENG Shi-li XU Hong-bin WANG Shao-na ZHANG Yi

. 2009, 9(2):  300-306. 

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Decomposition of sodium aluminate solution using methanol for production of coarse Al(OH)3 particles was studied. The effects of reaction temperature, concentration of caustic aluminate solution, caustic ratio, silica index, stirring intensity and methanol amount on the particle size and morphology of Al(OH)3 were examined. The results showed that spherical coarse particles of Al(OH)3 could be obtained under the conditions of solution composition with about 180 g/L Na2O, 1.5~1.6 molecular ratio and mass ratio of alumina to silica larger than 550, volume ratio of solution to methanol 1:1, and temperature 60 ℃. Their average particle size could reach about 80 mm. The longitudinal and radial growth speeds of Al(OH)3 growth unit were changed by addition of methanol. The radial growth speed was faster and growth unit became thinner with the more amount of methanol, for instance, with a value of about 100 nm when volume ratio of sodium aluminate solution to methanol was 1:1. Furthermore the crystal structure of Al(OH)3 particles changed from Bayerite to Gibbsite with the increase of temperature while the weight loss agreed with the theoretical value by DSC-TGA analysis.

Magnetic Roasting of an Oolitic Hematite and Limonite Ore in a Fluidized Bed Reacto

ZHOU Jian-jun ZHU Qing-shan WANG Hua-jun NI Wen

. 2009, 9(2):  307-313. 

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Magnetic roasting via a fluidized bed reactor was carried out for the beneficiation of a Yunnan oolitic iron ore. The magnetic roasting was performed at 550~800℃ for 2~20 min under mixed CO and N2 atmosphere. The results show that direct magnetic roasting followed by magnetic separation can only upgrade the concentrate to the total iron content of about 55% with a Fe recovery rate less than 70%, while with a pre-calcination process at 800℃ for 60 min to remove the crystalline water of iron ore prior to the magnetic roasting, a iron ore concentrate with total iron content of 60.18% at a recovery rate of 85.91% can be successfully obtained. The pretreated ore formed lots of pores by the pre-calcination process. These pores provided gas-diffusion channels to facilitate the reduction within the particles, which accelerated the growth of Fe3O4. Therefore, the Fe grade and recovery rate of iron ore concentrate could be improved.

Preparation of Fluorosilicone-containing Acrylate Latex with Enhancement of Microwave Irradiation

XIONG Sheng-dong LI Peng-hui YAN Shan-yin XU Zu-shun

. 2009, 9(2):  314-318. 

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An acrylate copolymer latex with core-shell structure was synthesized by multi-step seeded emulsion polymerization under microwave irradiation with hexafluorobutyl methacrylate, 3-glycidoxypropyltrimethoxysilane and butyl acrylate and methyl methylacrylate as raw materials. The chemical structure of the copolymer was determined by FT-IR, the size changing of latex particles in the polymerization process characterized by PCS, and their morphology characterized by TEM and AFM. The results show that the copolymerization under microwave irradiation had higher reaction rate than traditional heating, and during the shell polymerization process, the monomers could be better polymerized in formation of core-shell particles. The water contact angle of film reached 91.3o when the content of hexafluorobutyl methacrylate and 3-glycidoxypropyltrimethoxysilane used in copolymerization was 6%. The water absorption rate of core-shell latex film decreased from 20.1% to 3.54% as the content of hexafluorobutyl methacrylate and 3-glycidoxypropyltrimethoxysilane increased from 0 to 18%.

Decomposition of Ilmenite in KOH Sub-molten Salt

LIU Yu-min QI Tao WANG Li-na CHU Jing-long WANG Shao-na

. 2009, 9(2):  319-323. 

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Using KOH sub-molten salt as reaction medium, the effects of KOH concentration, reaction temperature, time, stirring speed and mass ratio of alkali to ore on the decomposition rate of ilmenite in KOH sub-molten salt were investigated through factorial and orthogonal experiments. The results showed that the more important factors among them were reaction temperature, time and KOH concentration. The high reaction temperature and KOH concentration were beneficial to the decomposition rate of ilmenite in KOH sub-molten salt. However, the decomposition rate of ilmenite decreased when the reaction temperature was more than 260℃. The decomposition rate of ilmenite was above 95% under the reaction conditions of KOH concentration 80%(w), stirring speed 700 r/min, reaction temperature 260℃, alkali-to-ore 5 and the reaction time 180 min. Furthermore, the decomposing process of ilmenite in KOH sub-molten salt was well interpreted with an unreacted shrinking core model under chemical reaction control.

Effect of Effective Concentration of High Melting Point Phases in RH Refining on Slag Sticking

LIANG Xiao-ping JIN Yang WANG Yu DUAN Hong-ling

. 2009, 9(2):  324-328. 

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To avoid crystallization of high melting point phases in refining slag, such as MgO×Al2O3 and FeO×Al2O3, during RH refining process, a calculation model of effective mass concentration for CaO-SiO2-MgO-Al2O3-MnO-FeO-CaF2 slag system was established based on the coexistence theory of slag structure, and the influences of slag components on effective concentrations of high melting point phases were studied. The results show that when slag basicity is more than 4, CaO/Al2O3 between 1.5 and 2.0, MgO content about 10%, FeO content about 17%, and CaF2 content less than 7.5%, the effective concentrations of MgO×Al2O3 and FeO×Al2O3 are at low level, MgO×Al2O3 and FeO×Al2O3 could not be crystallized from the refining slag. In this case, the slag sticking on RH immersion tube can be reduced. The calculation results are consistant with those of experiments, which may supply the theoritical basis for devolopment of slag sticking free modifying agent of RH refining slag.

Complexation Separation of Fe3+ by EDTA from Dissolved Reaction Product of NaOH Molten Salt with Titanium Slag and Preparation of TiO2

FENG Yang WANG Li-na XUE Tian-yan QI Tao CHU Jing-long WANG Jing-gang

. 2009, 9(2):  329-332. 

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Complexation of ferric ions in acid using EDTA (ethylene diamine tetraacetic acid) as chelating agent from the dissolved reaction products of NaOH molten salt with titanium slag was studied. The effects of EDTA added amount, reaction time, pH and temperature on the extraction rates of Ti4+and Fe3+ were investigated. The results showed that the extraction rate of ferric ions increased with increasing the amount of EDTA, prolonging the reaction time, reducing pH and raising the temperature. Spherical anatase TiO2 particles with average diameter of 100 nm could be obtained by hydrolyzing the residues at boiling point, and the content of TiO2 reached up to 99.3%.

系统与集成

Simulation of Fuel Ethanol Production from Lignocellulosic Biomass

ZHANG Su-ping Fran?ois Maréchal Martin Gassner REN Zhen-wei YAN Yong-jie Daniel Favrat

. 2009, 9(2):  333-337. 

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Models for hydrolysis, fermentation and concentration process, production and utilization of biogas as well as lignin gasification are developed to calculate the heat demand of ethanol production process and the amounts of heat and power generated from residues and wastewater of the process. For the energy analysis, all relevant information about the process streams, physical properties, and mass and energy balances are considered. Energy integration is investigated for establishing a network of facilities for heat and power generation from wastewater and residues treatment aiming at the increase of energy efficiency. Feeding the lignin to an IGCC process, the electric efficiency is increased by 4.4% compared with combustion, which leads to an overall energy efficiency of 53.8%. A detailed sensitivity analysis on energy efficiency is also carried out.

生化工程专栏

Increasing Voltage and Current by Connecting MFCs in Series and Parallel

LI Ding-jie HE Hui LU Cui-xiang LI Hao-ran DU Zhu-wei

. 2009, 9(2):  338-343. 

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Five two-chamber mediator-less microbial fuel cells were connected in series and parallel forms of cell stacks. The performances of cell stacks were studied when MFCs were running in different stages and using different substrates and electron acceptors. The results showed that connection in series or parallel increased voltage and current, respectively. Using oxygen and hexacyanoferrate as the electron acceptors, the voltage of connection in series stack enabled the voltage up to 1.186 V at output power density of 18.83 mW/m2 and 1.417 V at 51.51 mW/m2, respectively, and output current of parallel stacked cells was 3 mA at output power density of 22.66 mW/m2, and 6.86 mA at 65.22 mW/m2. The difference of individual cells in stacks was the main reason to cause cell reversal, and the cell with larger internal resistance tended to be pole reversal at large working current. Reasonable hybrid connection of MFCs reduced the energy loss caused by the difference of MFCs in series stack, when external resistance was 30 W, the output power density of adopted hybrid connection stack (30.3 mW/m2) was around 4 times as that of series stacked MFCs (6.58 mW/m2).

Characterization of Wool Fibers Modified by Using Microbial Transglutaminse

CUI Li FAN Xue-rong CHEN Jian; DU GUo-cheng; WANG Ping

. 2009, 9(2):  344-249. 

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The modification mechanism of wool fibers after different pretreatments with microbial transglutaminase (TGase) was analyzed by SEM, AFM, FT-IR ATR and SDS-PAGE. The results showed that KMnO4 pretreatment induced the alteration of characteristic peaks at around 1000~1200 cm-1 and the FT-IR absorption spectrum did not change obviously after protease pretreatment H2O2 and TGase treatment. The scale structure of wool surface was significantly damaged after KMnO4 and protease pretreatment in comparison with H2O2 pretreatment, which increased the average roughness of fiber surface from 12.5 to 24 nm. The surface morphology of fibers after TGase treatment was not evidently altered, but SDS-PAGE spectrum demonstrated that new biopolymers with higher molecular weight from wool keratin were formed by using TGase.

Preparation of Liposome of Volatile Oil from Houttuynia cordata Thunb. by Rapid Expansion of Supercritical Carbon Dioxide

WEN Zhen LIU Bo LI Qiong ZHENG Zong-kun YOU Xin-kui PU Yi-tao

. 2009, 9(2):  350-354. 

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The liposome of volatile oil from Houttuynia cordata Thunb. was prepared by modified rapid expansion of supercritical solutions (RESS), and physicochemical properties of liposome were characterized. The effects of pressure, temperature of supercritical CO2 and cosolvent (CH3CH2OH) amount on the liposome formation process were examined. Entrapment rate, drug loading, and average size of liposome were obtained as 83.2%, 5.2% and 332.5 nm respectively under the conditions of 30 MPa, 338 K and CH3CH2OH 15%. The results showed that the physicochemical properties including entrapment rate, dissolution rate and stability conformed to the standards of Chinese pharmacopoeia, and drug loading met the needs of injection dosage.

Effects of Surfactants on Simultaneous Saccharification and Fermentation of Wheat Straw to Ethanol

LUO Peng LIU Zhong

. 2009, 9(2):  355-359. 

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Five different non-ionic surfactants, BSA, Tween-20, Tween-80, PEG-4000 and PEG-6000, were evaluated for their ability to enhance simultaneous saccharification and fermentation (SSF) of wheat straw. The results indicated that all non-ionic surfactants tested improved the SSF of wheat straw, and Tween-20 was the most effective. Addition of Tween-20 decreased the enzyme loading while retaining the same ethanol concentration. The ethanol concentration of 18.7 g/L was achieved at a substrate concentration of 50 g/L at 37℃ and pH 5.0 using cellulase mixture (25 FPU/g of substrate for Celluclast 1.5 l and 15 IU/g for Novozym 188) for 72 h. Compared with the reference run without Tween-20, the ethanol concentration was increased by 14.0% whereas the residence time reduced by 12 h.

材料工程专栏

Performance of a Novel CuSO4-CeO2/TiO2-SiO2 Catalyst for NO Reduction with NH3 at Low Temperature

HE Yong TONG Hua TONG Zhi-quan; HUANG Yan XIA Bin

. 2009, 9(2):  360-367. 

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CuSO4-CeO2/TS catalyst impregnated on TiO2-SiO2 (TS) support prepared by coprecipitation method was investigated for the influences of the preparation parameters and operating conditions on the activities in selective catalytic reduction (SCR) of NO with NH3 at low temperature. The resistance to poisoning of H2O and SO2 was also studied. The results showed that about 98% NO conversion rate was achieved over CuSO4-CeO2/TS catalyst at 220℃ with a space velocity of 5000 h-1, in the presence of 4% O2, molar ratio of NH3/NO 1.1. The catalyst showed not only high resistance to H2O or SO2, but also the superior activity in the coexistence of H2O and SO2. The NO conversion rate of the catalyst remained high level about 95% during 33 h SCR reaction in the presence of H2O and SO2, and there was no sign of poisoning. The anti-poisoning performance of catalyst was superior to those of other catalysts reported in the literature.

Performance of Ag and F Doped TiO2 Photocatalytic Materials

SUN Tong ZHAI Yu-chun MA Pei-hua

. 2009, 9(2):  368-374. 

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TiO2 photocatalytic materials with silver, silver and fluorin doping, and porous nickel as carrier were prepared by hydrothermal method. The samples were characterized by XRD, TEM, SEM, FT-IR, UV-Vis and XPS. The photocatalytic performances of the samples were estimated by degrading Rhodamine B. The photocatalytic degradation of Rhodamine B follows the zero order reaction kinetics. The base of samples is anatase titanium oxide. After calcination at 500℃ for 0.5 h, the photocatalytic performance of materials has been improved. Increasing silver-doped amount, the photocatalytic performance of samples increases and then decreases. When the silver-doped amount is more than 0.6%, the photocatalytic performance of material increases with its doping, the optimum doping dosage is 1.2%. The photocatalytic performances increase by calcining, Ag optimum doping dosage is 0.8%. The photocatalytic performances of 1.2% silver and 2.0% fluorin jointly doped samples are better than those with silver singly.

Stability of Rh-coated Foam Monolith for Catalytic Partial Oxidation of Methane

DING Shi CHENG Yin-hong WU Chang-ning JIN Yong CHENG Yi

. 2009, 9(2):  375-380. 

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The stability of Rh-coated foam monolith with different pore sizes for catalytic partial oxidation of methane was investigated. The results showed that 0.3%(w) Rh coated foam with 3 mm in length and 0.32 mm in pore size had similar initial catalytic performances with the foam at 10 mm in length and 0.576 mm in pore size, but its deactivation rate was only 1/5 of the latter. The CFD modeling coupled with detailed elementary kinetics was successfully established and applied to predict the species concentration and surface temperature profiles within the two catalysts above. The foam with a smaller pore size, which had a higher catalytic surface area per unit volume, increased the rates of exothermic oxidation reaction and endothermic reforming reaction by 1.1 and 3.7 times, respectively. As a consequence, more steam reforming reaction occurred and its hot-spot temperature was 171℃ lower than the foam with a larger pore size. The hot-spot temperature of the foam with 0.576 mm in pore size was decreased by 235℃ after increasing its catalytic surface area per unit volume by 8 times.

Preparation of Silane Modified PDMS/Silicalite Hybrid Membrane and Its Pervaporation for Dilute Ethanol-Water Solution

YI Shou-liang SU Yi ZHOU Hao-li CHEN Xiang-rong SU Zhi-guo WAN Yin-hua;

. 2009, 9(2):  381-386. 

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With 3-aminopropyltrIethoxysilane as a coupling and surface modification agent for Silicalite-1 nanoparticles, polydimethylsiloxane (PDMS)-Silicalite filled pervaporation membranes were prepared. The modification effect of Silicalite and thermal resistant performance of the hybrid membrane were investigated by FT-IR and TGA. The effects of feed concentration, feed temperature, feed flow rate and downstream vacuum degree on the pervaporation performance of dilute ethanol/water solutions were also examined. The results showed that compared with pure PDMS and unmodified hybrid membranes, the selectivity of silane modified hybrid membrane could be improved by 136% and 45%. With the increasing of ethanol concentration in the feed from 5% to 69%, the membrane selectivity was decreased remarkably. Nevertheless, other operation parameters had a little effect on membrane selectivity.

Preparation of Molecular Surface Imprinting Material and Its Identification Properties for Bilirubin

CHEN Zhi-ping GAO Bao-jiao YANG Xiao-feng LI Yan-bin

. 2009, 9(2):  387-392. 

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Polyethyleneimine (PEI) was grafted onto the surface of silica gel particles via the coupling effect of 3-methacryloxypropyl trimethoxysilane (MPS), and the grafted particle PEI/SiO2 was prepared. Then, the molecular imprint polyethyleneimine on the surface of silica gel, MIP-PEI/SiO2, was prepared with bilirubin as a template molecule and ethylene glycol diglycidyl ether (EGDE) as crosslinking agent by using novel molecular surface imprinting technique. Both static and dynamic methods were adopted to study the identification properties of MIP-PEI/SiO2 for bilirubin. The experimental results show that MIP-PEI/SiO2 has higher selectivity ability and excellent combination property for bilirubin. Besides, MIP-PEI/SiO2 has excellent elution property, with the mixed solvent of EDTA and NaOH as the eluent, the desorption ratios of bilirubin reach 99.39% in 11 bed volumes.

Color Properties of Glass-infiltrated Alumina All-ceramic Dental Composite

ZHANG Dan ZHU Qing-shan

. 2009, 9(2):  393-397. 

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CeO2, Fe2O3 and Er2O3 were used as colorants in alumina infiltration glass system. The pigmented infiltration glass was prepared and then infiltrated in pre-sintered porous alumina, the reflecting spectra and color parameters of glass-infiltrated alumina composite were measured by spectrophotometer, and the effects of different colorants content on the color properties were investigated. Experimental results showed that CeO2 could endow the composite with yellow value, Fe2O3 could endow the composite with red value and decrease the lightness effectively, and Er2O3 could obviously increase the red value, but had slight effect on the lightness and yellow value. The chroma ranges were L*(lightless) in 73.5~91.6, a*(red-green value) in -2.84~4.11, b*(yellow-blue value) in 15.6~25.3. Following experiments showed that the chromaticity differences were not more than 1.5, which were considered to match.

Synthesis of One-dimension Mn Doped ZnO Nanostructures Using Radio Frequency Thermal Plasma

HU Peng SHI Chang-yong YUAN Fang-li LI Jin-lin

. 2009, 9(2):  398-402. 

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One dimensional ZnO nanostructures doped with Mn were synthesized using a radio frequency (RF) thermal plasma with the mixture of Zn and MnCl2 powders as staring materials. The influences of Mn doping on the morphology and properties of synthesized products were investigated. It is found that the peak positions of (100), (002) and (101) shift a little to the smaller 2q, which confirms that Mn is doped into ZnO crystal lattice. SEM, TEM and HRTEM were used to characterize the synthesized Mn doped one dimensional ZnO. The length of synthesized doped ZnO decreases from about 2 mm to 200 nm, and the diameter increases from about 30 nm to 100 nm when the mole ratio of Mn to Zn increases to 4%, respectively. The synthesized one dimensional Mn doped ZnO nanostructures exhibit ferromagnetism under normal temperature, and the magnetization increases with the increase of doped Mn concentration.

Effect of Li Doping on Catalytic Performance of LaNi/Al2O3 in Tar Reforming

KONG Ling-hua YUE Bao-hua WANG Xue-guang YU Fei ZHEN Qiang LU Xiong-gang DING Wei-zhong

. 2009, 9(2):  403-407. 

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The catalytic activity of LiLaNi/Al2O3 was evaluated in a fixed-bed reactor via steam reforming of toluene as a model tar compound. The results showed that addition of Li could improve the catalytic activity of LiLaNi/Al2O3 and enhance H2 content in the resultant gas mixture. XRD, SEM and TPR results illustrated that the addition of Li had great influence on the structure of LiLaNi/Al2O3 catalysts and the reduction ability of Ni2+ ions. The catalyst 0.5LiLaNi/Al2O3 possessed the optimal catalytic performance. LiLaNi/Al2O3 also showed good resistance to coking for steam reforming of tar at a high temperature of 750℃.

Synthesis, Characterization and Catalytic Performance of Trivalent Fe-substituted Mesoporous Aluminophosphate Molecular Sieves

LI Xin-zhu REN Hai-lun YANG Shu-lin

. 2009, 9(2):  408-412. 

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Fe-substituted aluminophosphate molecular sieves were prepared by hydrothermal crystallization and characterized with XRD, FT-IR, N2 adsorption, etc. The results showed that the samples were the typical mesoporous molecular sieves that were short of the long-range ordered crystal structure and had large surface area, which suggested that Fe3+ ion was successfully incorporated into the framework of molecular sieves and mainly existed in tetrahedral coordination after calcination. Fe-substituted aluminophosphate molecular sieves were effective for catalytic oxidation of phenol in aqueous solution with H2O2 as oxidant. Under the conditions of reaction temperature 60℃, reaction time 4 h, phenol initial concentration 3 mmol/L, H2O2 initial concentration 45 mmol/L and pH 4.5, the removal rates of phenol and COD reached 99.5% and 87.9%, respectively. Their catalytic performance was stable and the concentration of Fe3+ leaching-off was little in catalytic oxidation of phenol in aqueous solution.

Preparation and Properties of Micro-coiled Carbon Nanofibers and Polyvinyl Alcohol Composite

AN Yu-liang LIU Yan-qiu YUAN Xia ZUO Ji-cheng

. 2009, 9(2):  413-416. 

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Micro-coiled carbon nanofibers were prepared by chemical vapor deposition using Ni as catalyst. The composite of micro-coiled carbon nanofibers polyvinyl alcohol was synthesized at heating condition with the microcoiled carbon nanofibers treated by concentrated nitric acid. The effect of content of microcoiled carbon nanofibers on mechanic properties of composite was carried out. The mechanic properties of composite were improved up to 32% by the mono-disperse micro-coiled carbon nanofibers 0.4%(w), as characterized by SEM on the fracture section of composite, the nanofibers were uniformly distributed in the PVA base.