Table of Content

20 December 2011, Volume 11 Issue 6

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流动与传递

Solid Suspension Characteristics in a Three-phase Shallow Bubble Column

CAI Qing-bai DAI Gan-ce

. 2011, 11(6):  901-906. 

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The influences of aspect ratio (H/DT), gas sparger and solid concentration (Cs) on gas holdup and critical gas velocity of solid suspension (Ugc) were investigated in a 383 mm i.d. three-phase shallow bubble column. The results show that when H/DT is smaller than 1.5, gas holdup increases and Ugc decreases with the increase of H/DT. However, when H/DT is larger than 1.5, the effect of H/DT on Ugc is insignificant. Gas sparger has great effect on Ugc, when d/DT is equal to 0.4, the value of Ugc is minimum. Gas holdup decreases with the increase of Cs. The effect of Cs on Ugc is insignificant, when Cs is larger than 15%(j). Finally, the empirical correlation is proposed to describe their quantitative effects on Ugc to give some physical insights into the experimental phenomenon.

Fluidization Behavior of Oily Sludge-Sand Binary Particle Mixture

LIU Hui-e XU Ming-ming FU Yu CHEN Shuang QI Xuan-liang

. 2011, 11(6):  907-912. 

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The fluidization behavior of oily sludge (OS)-sand binary mixture was studied in a glass fluidized bed with 60 mm I.D. and 1200 mm height. The results show that the OS particles used cannot be fluidized alone, because of its high oil content and hence the high adhesive force between the particles. The OS can be smoothly fluidized when admixed with a certain fraction of sand. With the increase of OS content in the mixture, the defluidization process becomes gradual and with channeling. An equation similar to that of Kumar-Gupta put forward was fitted with the experimental data. And new parameters for different particle mixtures were obtained. Most of the errors in prediction of umf using the equation were lower than 5%.

Flow Characteristics of Turbulent Fluid in the Inner Half-coil Jackets of an Autoclave

LI Ya-xia HUA Bo WU Jian-hua ZHANG Ping

. 2011, 11(6):  913-918. 

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Fluid turbulent flow characteristics in the inner half-coil jacket of an autoclave were studied numerically and experimentally. Good agreement was found between the experimental and numerical results in the inner half coil jacket with curvature ratio d=0.133 and dimensionless pitch t=0.127. Based on orthogonal helical coordinate, the velocity field distributions were displayed including average axial velocity, secondary flow velocity and secondary flow stream function. The effects of Reynolds number Re, curvature ratio d and dimensionless pitch t on velocity fields and flow resistance were studied. The results show that at the fully developed turbulent flow condition, there are two positions of maximum average axial velocity on the semicircular cross section and the secondary flow patterns are stable four-vortex in the inner half-coil jacket. With the increase of Re and d, the intensity of secondary vortex and turbulent flow resistance of the inner half-coil jacket are both enhanced. Compared with the outer half-coil jacket, turbulent flow resistance fRe of the inner one increases 2.13%~7.72% in the range of 0.05≤d≤0.1, 10000≤Re≤18000.

Effect of Flow Field on Mixing, Decarburization and Inclusion Removal in RH Degasser

GENG Dian-qiao LEI Hong HE Ji-cheng

. 2011, 11(6):  919-925. 

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Based on the computational fluid dynamics, reaction thermodynamics and kinetics, the gas-liquid flow field, decarburization, collision and aggregation behavior among inclusions were investigated by numerical method. The numerical results show that the gas bubbles rise up near the wall in the up snorkel when the gas flow rate is 400 NL/min. The gas bubbles can reach the up snorkel centre when the gas flow rate increases to 1000 NL/min. The decarburization rate is about 45~70 mol/s during the first 3 s, decreases to 5 mol/s during 3~500 s, and decreases further after 500 s. And the inclusion mass concentration can be decreased to 5′10-5 after 14 min treatment. Furthermore, the predicted results agree well with the measured experimental results. Thus, the numerical simulation method can be employed to predict the critical technologic parameters during RH vacuum refining process.

Numerical Simulation of Gas-Liquid Two-phase Flow Behavior in the Top and Bottom Combined Blowing Converter

LOU Wen-tao LI Yong ZHU Miao-yong

. 2011, 11(6):  926-932. 

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The supersonic jet behavior of multi-hole top lance was described with the compressible model, and the prediction was validated by the previous measured results. Combined with the VOF and Lagrange multi-phase flow models, the flow field and mixing time of the converter were described, and the arrangement of bottom tuyeres was optimized. The results show that the mixing time of the pure top-blown converter is about 523 s, and the molten steel flow at the bottom of converter is weak. After performing bottom blowing, the molten steel flow velocity at the bottom of the converter increases exponentially and the mixing time is reduced to 99 s. The mixing efficiency using 3 bottom tuyeres is better than the case of 2 or 2 bottom tuyeres. The optimum range of the location of bottom nozzle away from the axis is 0.3D~0.4D, and the location should be closer to 0.4D.

An Optic Method Based on LED Reflection for Measurement of the Characteristics of Particle Suspension in a Liquid-Solid Stirred Tank

ZHOU Hong-bao LI Xiang-yang YANG Chao MAO Zai-sha ZHANG Guang-ji

. 2011, 11(6):  933-937. 

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An optic method based on LED reflection was proposed for determination of the characteristics of particle suspension in a liquid-solid stirred tank. The characteristics of particle suspension in water-silica two-phase system in an oval-bottomed stirred tank of 380 mm in diameter were measured using this method. The results show that appropriate location of measuring point for critical impeller speed Njs should be in the lower part of the tank and the radial position has little effect on Njs. Njs obtained by the optic method was close to that obtained by the withdrawal sampling method in the whole range of solid loading and the average relative error between them was only 4.0%. Njs obtained by the visual observation was bigger than those from other two methods. The optic method can be operated faster and more easily than the withdrawal sampling method and applied in opaque vessels compared with the visual observation. Nus quickly determined by the optic method is bigger with higher solid loading.highest material flow rate 500, 620 and 820 m3/h, separately. Based on the transport characteristics and pressure gradient trend along the conveying direction, the pipeline could be divided into developing, transition and developed sections.

Transport Characteristics of Particulate Materials in a Double-tube-socket Pipe Pneumatic Conveying System

ZHANG Chun-xia; DU Yan

. 2011, 11(6):  938-942. 

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Pulverized coal ash, fluorite powder and lime powder were chosen as typical materials. The transport experiment was carried out in a double-tube-socket pipe pneumatic conveying system with 100 m length and 100 mm diameter. The effects of powder diameter and density on their pneumatic conveying were analyzed. In the research range, the lowest air volume flow rate of pneumatic conveying for pulverized coal ash, fluorite powder and lime powder was 200, 300 and 800 m3/h, the lowest pressure gradient of conveying 0.8, 1.2 and 1.1 kPa/m, and the air volume flow rate of highest material flow rate 500, 620 and 820 m3/h, separately. Based on the transport characteristics and pressure gradient trend along the conveying direction, the pipeline could be divided into developing, transition and developed sections.

反应与分离

Kinetic Modeling of Molten Iron Demanaganization with Flux Injection in a Torpedo-shaped Furnace

ZHU Cheng-yi LI Guang-qiang CHEN Zhao-ping XIA Xing-ming HONG Xiao-jie

. 2011, 11(6):  943-950. 

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Based on the coupled reaction model, a kinetic model was developed for hot metal demanganization with flux injection in a torpedo-shaped furnace using oxidation slag, considering the effects of penetration ratio and residence time of the injected flux, mixing time of the hot metal bath on demanganization rate, and then the model was validated. The calculated results obtained by simulating the actual process using this model show that when the powder containing 58.5% FeO and basicity controlled at 0.85 carried by oxygen with 10 Nm3/min flow rate is injects into 250 t hot metal at 1623 K and the injection rate controlled at 400 kg/min, silicon content in hot metal decreases to the lowest level after treatment for 2~3 min. Demanganization rate increases gradually only silicon content in hot metal decreases below 0.3%. Manganese content decreases to the value below 0.1% which is the lowest level in the present bath after treatment for 6~7 min, which can meet the requirements of low manganese steel. Desiliconization rate is higher than that of demanaganization under the calculation conditions, and decarburization is observed, while phosphorus content is nearly not changed. The demanganization is enhanced by decreasing the particles size of injected flux to 25 mm, increasing the immersion depth of lance to 1.6 m, increasing powder supply rate to 400 kg/min, increasing FeO content in the flux suitably and decreasing silicon content to a certain level before demanganization when the powder is ensured to contact with hot metal fully as well as avoid agglomerating and blowing out of the bath.

Experimental Study on Combustibility and Reactivity of Pulverized Coals Injected in Blast Furnace in Pansteel

HE Xin-jie ZHANG Jian-liang Cheng-lin; WEN Yong-cai FU Wei-guo

. 2011, 11(6):  951-957. 

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The combustibility and reactivity of 7 kinds of clean coal, 6 kinds of lean coal, current mixed coal and 2 kinds of coked dust ash in Pansteel were investigated with thermogravimetric analysis. The results show that compared with lean coal, clean coal has higher initial and terminated burning temperature and longer burning process. The initial burning temperature of current mixed coal is 509℃, which is 46℃ and 12℃ higher than that of lean coal and clean coal respectively. The combustion rate of current mixed coal at different temperatures is low, and its combustibility poor. The reactivity of clean coal is related to its ash content, the coal with lower ash content has better reactivity to CO2. The reaction rate of current mixed coal is 58.62% at 1200℃, which is 12.61% and 15.30% lower than that of lean coal and clean coal respectively. The present research results on the combustibility and reactivity of all these samples indicate that it is necessary to improve the scheme of blended-coal in Pansteel.

Experimental Study on Precipitation and Dissolution of Carbonitrides in X80 Steel in Continuous Casting-Hot Rolling Region

ZHU Zheng-hai QIU Sheng-tao

. 2011, 11(6):  958-964. 

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As for the techno-interface of continuous casting-hot rolling region, the precipitation and dissolution of carbonitrides in X80 steel were studied during continuous casting, roller conveying, stack cooling and heating units in typical slab process flow by hot simulation experiment based on the study of heat transfer. The results showed that Ti(C, N), (Ti, Nb)(C, N) and NbC were precipitated in turn in continuous casting and conveying. A few (Ti, Nb)(C, N) particles were not dissolute totally after heating. The precipitation of carbonitrides was effected significant by cooling rate in conveying. When slab was conveyed at 6.0℃/min rate and then cooled down to 750 or 600℃, the distributing density of carbonitride particles was higher, and their average equivalent diameter smaller, some carbonitride particles were distributed along the austenitic grain boundaries and the elements related to the carbonitride particles were supersaturated. When slab was conveyed at 0.3℃/min rate and then cooled down to 400℃, the distributing density of carbonitride particles was lower, and their average equivalent diameter bigger, the carbonitride particles precipitated fully. The behavior of carbonitrides in slab was affected by thermal course in heating. The status of carbonitrides was affected insignificant by thermal course after heating. The basic reason of carbonitride particles distributed along the austenitic grain boundaries was cooling rate.

Solvent Extraction of Lignans from Schisandra Crude Extractive Solution

ZHOU Ling WANG Xue-kui XIAO Qing-gui WANG Tie-feng XU Hong-bin

. 2011, 11(6):  965-971. 

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To establish the suitable technology of schisandra lignans with solvent extraction, the single factor experiments and surface analysis were adopted to study the effects of such factors as phase ratio, extraction time, temperature and stirring intensity. The best extraction solvent was petroleum ether and the suitable process conditions were phase ratio 4:1 and temperature 41℃, after 16 min extraction, the extraction rate of schisandra lignans was greater than 90%. The purity of total schisandra lignans increased from 1.28% to 25.5% by using the above technique. The extraction mechanism was also analyzed, schisandra lignans were extracted in the form of neutral molecules and the extraction process was controlled by mass transport diffusion.

Separation of Pd(II) by Complexation-Ultrafiltration Process with Poly(acrylic acid) Sodium

ZENG Jian-xian ZHANG Jiao-jiao ZHOU Hu FU Rong SHAO Qiang

. 2011, 11(6):  972-977. 

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Complexation-ultrafiltration process for separation of palladium(II) from aqueous solution was investigated by using poly(acrylic acid) sodium (PAAS) as a complexing agent. The effects of polymer/metal mass ratio (rp/m), pH value and transmembrane pressure (Dp) on permeate flux (J) and palladium rejection coefficient (RPd) were investigated. It was found that J did not change with increasing of rp/m, and increased with pH or Dp. RPd increased with rp/m or pH, but did not vary with Δp. The concentration experiment was carried out at rp/m=2 and pH=6. The results showed that J declined slightly and RPd was about equal to 1 with increasing of volume concentration factor (Fv). Palladium concentration in the retentate (Cr) increased linearly with Fv, whereas palladium concentration in the permeate (Cp) was always about 0.07 mg/L. The decomplexation experiment was done at pH=3 by using the previous concentrated solution. Cr did not change but Cp increased gradually to 100.9 mg/L with increasing of decomplexation time. It took about 13 min to get the decomplexation equilibrium. The decomplexation rate of palladium(II)-PAAS complexes reached 56.3%. Further, an ultrafiltration experiment was carried out by using the washing water. If the volume of washing water was 3.5 times larger than the feed volume, Cr decreased from 179.3 to 5.2 mg/L, which corresponded to palladium removal rate of 97.1%.

Preparation of Chitosan-b-Cyclodextrin Cross-linked Copolymer and Its Adsorption to Puerarin

SU Miao WANG Li-li LIN Qiang

. 2011, 11(6):  978-983. 

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A new type chitosan-b-cyclodextrin copolymer was prepared with the chitosan and b-cyclodextrin as materials, sodium periodate as oxidant, epichlorohydrin as cross-linker using inverse suspension method. Its structure was characterized by FT-IR and SEM. Its adsorption and desorption performance to puerarin, and reusability were investigated. The results showed that the optimal conditions were: adsorption time 4 h, temperature 35℃, pH=7 and initial concentration of puerarin 0.5 mg/mL, the maximum adsorption of puerarin on chitosan-b-cyclodextrin was 52.43 mg/g, its elution rate of puerarin 89.69%, and it showed good reusability.

Alkali Leaching Kinetics of Amorphous Aluminum Hydroxide Mud in Chromium Hydroxide Residue for Aluminium Recovery

TIAN Lei XU Zhi-feng LI Ping XU Hong-bin WANG Shao-na

. 2011, 11(6):  984-989. 

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With the aluminum residue containing chromium hydroxide [Cr(OH)3] and aluminum hydroxide [Al(OH)3] as raw material, the alkali leaching kinetics of Al(OH)3 in the residue has been studied in the following conditions: leaching temperature from 343 to 373 K, initial concentration of sodium hydroxide 150 g/L, ratio of liquid to solid 15 mL/g, and agitation speed 450 r/min. The experimental results show that a linear relationship between the leaching rate of aluminum and leaching time exits before the leaching equilibrium. The time consumed for which the leaching of aluminum reaches at the equilibrium is shortened with the increase of leaching temperature. The leaching rate of aluminum is increased with the increase of temperature in 343~373 K, finally the leaching rate of aluminum is 94.07%, leading to the main content of chrome oxide product at 98.12%. The apparent activation energy is determined as 62.38 kJ/mol for the leaching of aluminum. The leaching of aluminum follows the shrinking core model with surface reaction control.

Batch Adsorption of Mn2+ from Aqueous Solution by Agricultural Waste Biomass Taro Stem

TANG Wen-qing LI Xiao-ming ZENG Rong-ying LI Chun-li WANG Yin-peng

. 2011, 11(6):  990-993. 

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With waste taro stem as novel biosorbent, the effects of pH value, temperature, adsorption time and Mn2+ initial concentration on the biosorption capacity of taro stem for Mn2+ were studied by static adsorption experiment. The unit mass of adsorption process was analyzed in thermodynamics and kinetics and adsorption isotherm. The results showed that removal rate of Mn2+ in wastewater was more then 90.79% and adsorption capacity up to 18.16 mg/g when taro stem usage was 6 mg/L, adsorption time 60 min, initial pH=4 of wastewater and temperature 30℃. Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm parameters. The Freundlich isotherm was found to be the better theoretical correlation of experimental data. The kinetic experimental data were properly correlated with the pseudo-second-order kinetic model. Thermodynamic parameters of DG, DH and DS were calculated. Their values showed that the overall adsorption process was endothermic and spontaneous.

过程与工艺

Preparation of Synthetic Rutile Using Activation Modification-Selective Leaching Process from Preoxidation Titanium-containing Slag

LU Hui XIE Gang MENG Jun YANG Wen XIE Hong-yan

. 2011, 11(6):  994-1001. 

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A new process of activation modification-selective leaching for titanium-containing slag titanium-containing slag to prepare synthetic rutile was presented. The effects of modifier, ratio of slag to modifier, activating temperature, activating time, particle size of the preoxidation slag and acid leaching system on the content of synthetic rutile TiO2 were investigated. The results show that Na2CO3 was a relatively ideal modifier, when the activation reaction process was carried out under the conditions of temperature 900℃, activating time 120 min and mass ratio of slag to modifier 5, high purity synthetic rutile TiO2 of about 92% was obtained after high pressure acid leaching-washing-hydrolysis-calcination process from activating product, which meets the requirements of titanium dioxide pigment by the chlorination process in industry.

Optimization of Fluidized Chlorination Process Conditions of Natural Rutile Powder

NIU Li-ping ZHANG Ting-an LU Guo-zhi NI Pei-yuan LIANG Xi-bin OUYANG Quan-sheng MENG De-long JIANG Xiao-li

. 2011, 11(6):  1002-1009. 

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Taking natural rutile as the research object, its mineral composition and microstructure are analyzed by chemical analysis, SEM, XRD, etc., and the influences of process parameters on boiling chlorination reaction activity of natural rutile is studied by single-factor experiments. The results show that the surface structure of natural rutile is dense; appropriate process parameters of boiling chlorination process are: temperature 950℃, particle size of natural rutile -96 mm, particle size of calcined petroleum coke -150 mm, petroleum coke 30%, chlorine flow rate 0.036 m3/h, reaction time 30 min, gas pressure 0.14 MPa, concentration of chlorine 100%. In such conditions, the chlorination rate of natural rutile can reach over 95%. Contrast experiments of natural rutile and high-titanium slag shows that calcium and magnesium are the key elements of chlorination reaction and final chlorination rate. The research on boiling chlorination kinetics of natural rutile indicates that the process meets the contracting unreduced nucleus model without solid products. When the temperature range is from 900℃ to 1000℃, the activation energy is 9.17 kJ/mol. The reaction is controlled by diffusion. So the effective way to improve the reaction efficiency is intensifying the mass transfer and enlarging the effective reaction surface.

Effect of Mechanical Milling on Preparation of Plate-shape Magnesium Hydroxide Nanoparticles from Calcined Magnesite

YANG Su-ping LU Xu-chen WANGTi-zhuan; ZHANG Zhi-min YAN Yan

. 2011, 11(6):  1010-1016. 

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Lamellar and well dispersed magnesium hydroxide (MH) nanoparticles were synthesized from magnesite by calcination, wet milling, and hydrothermal treatment. The effects of grinding aid, milling time, and mass ratio of ball to powder on the dispersion, particle size, and morphology of MH particles were studied. The results showed that mechanical milling could accelerate hydration process of calcined magnesite, which could provide precursor with high dispersion for the following hydrothermal treatment. When PEG400 or PVP was used as grinding aid for milling the calcined magnesite for 2~4 h with the mass ratio ball to powder between 20:1~30:1, the dispersibility of MH particles was largely improved, and the size and size distribution of MH particles were reduced.

Optimal Parameters of Response Surface Methodology for Preparation of Magnesium Hydroxide Flame Retardant

LIU Zhi-qi LI Li-juan CHEN Yun-fa LI Xiao-kun ZHANG Yan-ling SHEN Gen-li

. 2011, 11(6):  1017-1023. 

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The yield of magnesium hydroxide was investigated via response surface methodology using bischofite and aqueous ammonia as raw materials. The experimental results indicated that the effects of reaction temperature, magnesium ion and aqueous ammonia concentrations on the yield of magnesium hydroxide gradually decreased. In particular, reaction temperature and magnesium ion concentration had a significant influence on the yield. After the regression and fitting of the response value and each factor, the regression equation was obtained. As proven by experiments, the predicted value and actual value showed a good fit. The products of the center experiment were characterized by particle size analysis, scanning electron microscopy, and X-ray diffraction. The results show that the morphology is irregular and shows a lamellar structure. The particles have a narrow size distribution ranging from 0.64 to 0.68 mm of D50 size. The difference in particle size of D10 and D90 is less than 0.91 mm, and the purity very high.

Smelting Conditions of Reduction Ironmaking from Ilmenite Mixed with High Phosphorus Iron Ore by Top-blown Oxygen

HOU Ya-li WANG Hua QING Shan

. 2011, 11(6):  1024-1029. 

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The ironmaking process of oxygen top-blown smelting reduction from high phosphorus iron ore mixed with ilmenite was studied. The experiments were conducted to investigate the effects of slag basicity, temperature, molar ratio of carbon to oxygen, oxygen-blowing time, holding time and oxygen flow rate on iron recovery rate. The experimental results showed that the iron recovery rate increased with increasing of smelting temperature, content of CaO added, molar ratio of carbon to oxygen, oxygen-blowing time, holding time and oxygen flow rate within a certain range. The slag and iron were well separated and iron recovery rate was up to 96.17% under the conditions of holding time of 30 min at 1500℃, slag basicity of 1.3, molar ratio of carbon to oxygen of 1.0, oxygen-blowing time of 10 min and oxygen flow rate of 350 L/h.

生化工程专栏

Complex Mutation of Klebsiella pneumoniae Producing 1,3-Propanediol from Biodiesel-derived Glycerol

HU Xiao-li NAN Nan XIU Zhi-long

. 2011, 11(6):  1030-1037. 

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Based on the complex treatment of plasma and LiCl, a mutant strain of Klebsiella pneumoniae was isolated by using the medium containing FeCl3 and selective pressure. The mutant strain named KpM30 improved 1,3-propanediol (1,3-PD) production from biodiesel-derived glycerol through producing less organic acid than the wild strain. The fed-batch fermentation in a 5 L bioreactor showed that the production of 1,3-PD reached 70.2 g/L, its yield on glycerol was 0.576 (mol/mol), which were increased by 24.9% and 17.7% compared with the wild strain. Meanwhile, the production of lactic acid was decreased by 47.0%. According to the metabolic analysis, the production of ATP and NADH2 by KpM30 were 1.6-fold and 1.3-fold of the wild strain at the beginning of the fermentation. At the end of the fermentation, the carbon ?ux ?owed from glycerol to 1,3-PD was increased by 22.6%. For the less production of organic acid and better use of biodiesel-derived glycerol, this mutated strain was helpful for the separation process after fermentation and the integrated bioprocess combining biodiesel with 1,3-PD production.

Candida parapsilosis Whole Cell Catalyzed Asymmetric Reduction: Inhibition and Removal of Substrate (Product)

YUE Yong-tang XU Yan MU Xiao-qing

. 2011, 11(6):  1038-1043. 

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Asymmertric reduction synthesis of (S)-4-chloro-3-hydroxybutyrate ethyl (S-CHBE) from 4-chloro-3-oxo-butyrate ethyl (COBE) was introduced as model reaction. Candida parapsilosis CCTCC M 203011, an efficient biocatalyst, was obtained from laboratory preserved strains, which could reduce COBE to S-CHBE with high efficiency and enantioselectivity. 96% in yield and over 99% in e.e were achieved respectively when COBE was 20 g/L. However, the product inhibition to enzymatic reaction and substrate toxicity to enzyme/microbial cell were the main reasons which restricted the reaction efficiency. Coupled with aqueous-organic biphasic system and substrate feeding strategy, the product was removed in situ and the substrate concentration in aqueous phase controlled below 4 g/L, the accumulated concentration of COBE was increased to 60 g/L with 95% in yield. And a higher product titer (approximately 230 g/L) and high optical purity (>99%) were achieved through increasing the usage of cell.

Optimization of Pyruvate Production Conditions Based on Environmental Adaptability of Torulopsis glabrata in a Pilot Plant Scale

YANG Song-xin WANG Meng WANG Jun LI Zhen CHEN Jian;

. 2011, 11(6):  1044-1049. 

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The production conditons of pyruvate at a pilot scale of 30-L fermentor through increasing environmental adaptability of Torulopsis glabrata were optimized. The fermentation parameters of T. glabrata at 3-L and 30-L fermentors were compared and its mechanism was elucidated. Following the mechanism, the nutrient (nitrogen and thiamine concentration) and environmental (dissolved oxygen) conditions were studied and optimized in 30-L fermentor, the optimum conditions were obtained as followed: 7 g/L urea, 18 mg/L thiamine and 2.0 L/min aeration rate. With the conditions, the titer, yield and productivity of pyruvate were achieved at 84.2 g/L, 0.72 g/g and 1.40 g/(L×h), respectively, which were 21.3%, 13.2% and 12.9% higher than the corresponding values of the control.

Scale-up Cultivation of Animal Cells in a Novel Disposable Perfusion and Current Bioreactor

XIE Bo LI Luan-feng DU Chun-ling HAO Su-juan WU Shu-yin HUI Mi-zhou

. 2011, 11(6):  1050-1054. 

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A novel disposable perfusion and current bioreactor with 5~10 L work volume was used for scale-up cultivation of six kinds of animal cells. Several important parameters were controlled on-line, including cultivation temperature, pH value and dissolved oxygen (DO). The cell density, viability and consumption of glucose were determined and analyzed in the cultivation process. The concentration of adherent MDCK, VERO and DF-1 cells reached 4.8×106, 1.0×107 and 1.5×107 mL-1 after 6 d cultivation, respectively. They were in good condition and their viability was above 90%. After serum-free suspending domestication, the suspension cells of CHO, BHK-21 and Sf9 were transferred into the current bioreactor with the initial inoculation concentration of 2.0×106, 2.1×106 and 2.15×106 mL-1, respectively. The highest concentration of these cells reached about 2.0×107, 2.1×107 and 1.8×107 mL-1, the continuous cultivation time lasted 13, 12 and 10 d, respectively.

Direct Utilization of Circulating Fluidized Bed Combustion Ash of Distilled Spirits Lees as Fertilizer

SONG Yang WANG Yin; YAO Chang-bin ZHANG Yu-ming WANG Chang YI Bin YANG Jun XU Guang-wen

. 2011, 11(6):  1055-1059. 

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The feasibility of utilizing the circulating fluidized bed combustion ash of distilled spirits lees as fertilizer was investigated. The rape culture experiment was carried out in 5 different kinds of soils, and the rape growth states in the germination and growth stages were measured to evaluate the effect of adding ash to the soils as fertilizer. The results show that the ash exhibited different effects on the rape growth in different culture stages. There was an antiblastic effect on the rape growth in the germination stage in a loamy soil, but the rape growth was much improved when adding the ash to a clayey soil. The latter led the mature rape to having obviously increased net height and weight. The ash could change the pH value of acid soil into neutral state, facilitating the humic acid decomposition and plant growth. Comparing the soils at soil:ash=5:1(w) with original soil, the increased amplitudes of net height of rape in Guojiaohong Turang, Qingke Turang and Fuyang Turang were 80.1%, 80.9% and 163.6%, respectively. As consequence, it was feasible and effective to use directly the combustion ash of distilled spirits lees as fertilizer.

材料工程专栏

Solid-phase Synthesis of S and Cr Co-doped TiO2 Mesoporous Materials with Visible Light Degradation Property for Neutral Red

SHI Feng-xiang LIU Shao-you FENG Qing-ge

. 2011, 11(6):  1060-1067. 

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S and Cr co-doped TiO2 (S-Cr-TiO2), S-doped TiO2 (S-TiO2) and Cr-doped TiO2 (Cr-TiO2) mesoporous nanomaterials are synthesized by solid-state reaction. Their textural properties are characterized. And, the visible light degradation properties of neutral red (NR) on the materials are investigated. The results show that S atom as S6+ and Cr as Cr3+ and/or Cr6+ states are incorporated into the lattice of TiO2 or interstice of TiO2 lattice. The BET specific surface areas of 148.2, 134.6 and 122.8 m2/g, as well as the pore distribution centres of 2.4, 2.6 and 3.06 nm for S-TiO2, Cr-TiO2 and S-Cr-TiO2 (S/Cr=1:1, molar ratio) materials are obtained, respectively. Moreover, the areas of S-Cr-TiO2 mesomaterials decrease with increasing of S/Cr molar ratio. The bonds of Ti?O?S and Cr?O?S and the trace of Cr2O3 and CrO3 exist in the S-Cr-TiO2 mesoporous materials. S and Cr co-doped TiO2 can effectively embarrass the crystal growth of TiO2. The UV-Vis spectra display that the adsorption region of S-Cr-TiO2 materials covers the visible light region and extends to near infrared light region. Moreover, at 25℃, pH=6.5, the high catalytic activity for NR is found on the S-Cr-TiO2 (S/Cr=3:2) meso-material irradiated by the visible light. Within 60 min, the visible light degradation rate of NR on the S-Cr-TiO2 meso-material is 91.8%, which is 2.32, 1.74 and 2.11 times corresponding to pure TiO2 (39.6%), S-TiO2 (52.7%), Cr-TiO2 (43.4%), respectively. The atomic percentage and transformation between Cr3+ and Cr6+ in S-Cr-TiO2 meso-materials control the degradation rate of NR, and the Cr6+ ions act as a key role on S-Cr-TiO2 catalysts.

Molding and Characterization of Powder Activated Carbon with High-Si Ash Made from Distilled Spirits Lees

ZHAO Wei WANG Yin; LI Qiang YANG Juan LIU Yun-yi XU Guang-wen

. 2011, 11(6):  1068-1074. 

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The activated carbon (AC) made from distilled spirits lees has high content of Si-rich ash. The molding methods of such AC by using carboxymethyl cellulose (CMC), coal tar and leaching solution from alkali treatment of the high-Si ash AC as the binder were investigated. The results showed that using only CMC or coal tar as the binder, the compressive strength of molded AC at a pressing pressure of 4 MPa reached the expected 120 N/cm, but the iodine adsorption capacity was lower than 400 mg/g. When using the silica alumina sol made with the leaching solution as the binder, mixing silica alumina sol and a small amount of CMC allowed the molded AC to have the satisfied compressive strength, while its adsorption capacity of iodine reached over 600 mg/g, higher than the AC molded with CMC or coal tar only, and original AC powder. The molded AC was characterized by FT-IR, XRD and SEM, and its binding mechanism analyzed.

Study on Slag System for Smelting of Ultrapure Low-pressure Rotor Steel

LU Ye TANG Ping WEN Guang-hua GAO Jian-jun

. 2011, 11(6):  1075-1080. 

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The EAF-LF-VD-VCD process for production of ultrapure low-pressure rotor steel is used in Yi Zhong. In order to satisfy the compositional requirements of the steel, based on theoretical analysis, the proper compositions of highly efficient dephosphorization slag and desulfurization slag are determined by the experimental study in laboratory and thermodynamic calculation. Among them, in the desulfurization slag, the content of SiO2 less than 6% can avoid the phenomenon occurrence of silicon increment, moreover the content of Al2O3 within 2%～4% can avoid that of aluminum increment. The production practice shows that the dephosphorization slag of EAF and desulfurization slag of LF-VD optimized by this study can achieve high efficiency of dephosphorization and desulfurization, and meet the compositional requirements of the ultra pure low-pressure rotor steel.