The Chinese Journal of Process Engineering

Numerical Simulation on Gas-Liquid Two Phase Flow in Continuous Casting Tundish with Bottom Gas Blowing

Zhan Shu-hua;OU Jian-ping;Xiao Ze-qiang

. 2005, 5(3): 233-240.

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Gas-liquid two phase flow in a tundish has been studied with a water model, prototype of which is the one in Meishan Iron and Steel Corporation. Experimental results show that with bottom gas blowing, tiny, steady and uniformly distributed bubbles can be produced and bubbly flow pattern forms in the tundish, uprising bubbly flow can destroy the laminar-like flow in the tundish and enhance flow mixing, on the other hand, the uprising bubbles can form a baffle-like gas column, which is in favor of inclusion removal. Based on the experiments, an Eulerian multi-fluid model is used to simulate gas-liquid bubbly flow in the tundish, Sato model is incorporated to include bubble-induced turbulence, Grace model is used to model inter-phase drag force, buoyancy is considered with Boussinesq approximation, turbulence dispersion force is also included with the model of Lopez. Numerical results well agree with those from experiments.

Total Distribution and Liquid Composition of Products from Coal Topping Process in a Downer Reactor

WANG Jie-guang;LU Xue-song;YAO Jian-zhong;LIN Wei-gang;DU Lin

. 2005, 5(3): 241-245.

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A hot downer reactor system integrated with a circulating fluidized bed was built to examine its performance in the coal topping process. The effects of reaction temperature and coal particle size on the total product distribution and liquid composition were determined for Huolin River coal (Inner Mongolia, China). The results show that increasing temperature can increase the yields of gas and liquid products, and a larger coal particle size leads to a lower liquid yield. The experimental results exhibit a promising product distribution. As the pyrolysis temperature was 660℃, the coal particle size was less than 0.28 mm and feed rate was 4.7 kg/h, the yield of light tar (hexane soluble fraction) reached 7.5% (dry coal basis, w). The composition of light tar was phenols (57.1%, w), crude gasoline (aliphatics, 12.9%), aromatics (21.4%), and polar and basic groups (8.6%). The closeness to plug flow pattern of the gas and solids in the downer makes it a promising reactor for the coal topping process.

Experimental Study on the Bubble Behavior in Gas-Liquid External Loop Reactors

ZHANG Tong-wang;WANG Jin-fu;JIN Yong

. 2005, 5(3): 246-250.

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This work dealed with the variation of bubble behavior in axial and radial directions. It was shown that the bubble behavior at the distributor region was axially unsymmetrical. The gas holdup and bubble velocity increased with increasing superficial gas velocity. The gas holdup in both the riser and downcomer and the bubble velocity in the riser decreased gradually from the center to the wall while the bubble velocity in the downcomer was almost uniform in the radial direction. The gas circulating rate increases with increasing superficial gas velocity and the trend of this increase became slower with the increase of superficial gas velocity.

Research on the Flow Field in the Exit Tube and the Mechanism of Pressure Drop Reduction in a Cyclone Separator

WANG Jian-jun;WANG Lian-ze;LIU Cheng-wen

. 2005, 5(3): 251-254.

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Laser Doppler Velocimetry (LDV) was used to measure the flow field in the exit tube of a cyclone separator. It was found that the high speed rotating flow, reverse flow region and turbulent fluctuation were contributed to the pressure loss in the exit tube. When a stick existed in the cyclone separator, the flow field in the exit tube changed, the tangential velocity turned smaller, the reverse flow region disappeared, and the turbulent fluctuation became weaker, so the pressure loss of the cyclone separator decreased. These changes were found to be related to the width and shape of the stick cross-section.

Extraction of Industrial Lipase with CTAB-based Mixed Reverse Micelles

SHEN Rui;LIU Jun-guo;XING Jian-min;LIU Hui-zhou

. 2005, 5(3): 255-259.

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The extraction of industrial lipase with mixed reverse micelles formed by CTAB with Tween, TRPO, TBP and butyl acetate was investigated. The transfer of industrial lipase to the mixed reverse micelles formed from CTAB with Tween85, TRPO, TBP, butyl acetate was higher than that of the reverse micelles formed with CTAB reverse micelles. The addition of TRPO, TBP and butyl acetate to the CTAB reverse micelles had no effect on the backward transfer of industrial lipase. The mixed reverse micelles formed from CTAB with Tween60, Tween40 could obviously enhance the industrial lipase backward transfer. The activity recovery of industrial lipase with the mixed reverse micelles formed from CTAB with TRPO was about 70%, which was the best in these mixed reverse micelles tested.

Enhanced Activity Recovery of α-Chymotrypsin during Reverse Micelles Extraction by Addition of Competitive Inhibitor

LIU Jun-guo;SHEN Rui;XING Jian-min;YANG Cheng-li;LIU Hui-zhou

. 2005, 5(3): 260-264.

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The effect of phenylboronic acid, a competitive inhibitor, on the extraction process and activity recovery of a-chymotrypsin by AOT[sodium 1,4-bis(2-ethylhexyl) sulfusuccinate] reverse micelles was studied. A moderate increase of extraction and in significant change of stripping were found when 2 mmol/L phenylboronic acid was added into the AOT reverse micelles system. The profound effect was that the activity recovery was greatly enhanced. The stability of enzyme activity was time dependent: the addition of phenylboronic acid induced enhanced activity recovery in a prolonged contact time during extraction and stripping. The specific binding of phenylboronic acid to chymotrypsin was considered to account for the stabilizing effect of enzyme activity during reverse micelles extraction.

Solubility of Benzoic Acid in Supercritical Carbon Dioxide with Different Cosolvents

LI Ying;SHI Bing-jie;ZHANG Ze-ting;JIN Jun-su;YU En-ping

. 2005, 5(3): 265-268.

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The solubility of benzoic acid in supercritical carbon dioxide with or without ethanol, ethyl acetate, ethylene glycol as cosolvent were measured at temperatures of 308.15, 318.15 and 328.15 K and pressures from 8.0 to 23.0 MPa respectively. It is revealed that the cosolvents added into the supercritical carbon dioxide could enhance the solubility of benzoic acid remarkably, and the effects of the three kinds of cosolvents were different. The enhancement degree of solubility by the cosolvents is ranked with the order: ethanol>ethylene glycol>ethyl acetate. In addition, the effects of temperature, pressure and cosolvent on the solubility were also discussed. The measured data of the solubility of benzoic acid in supercritical carbon dioxide were correlated with those calculated with the Sovova equation.

Lysozyme Solubilization Using the New Mixed Reversed Micellar System

LIU Yang;SHI Qing-hong;ZHAO Li-ming;SUN Yan

. 2005, 5(3): 269-272.

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A new mixed reversed micellar system composed of the anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate(AOT) and nonionic surfactant poly(oxyethylene) nonylether(OPE4 with polymerization degree of 4) was prepared and the solubilization of lysozyme in the mixed reversed micelles was investigated under different conditions. The results exhibited that this reversed micelle system had more water content, and the water content was kept to be constant at a wider concentration ratio of AOT to OPE4, which could be ascribed to the change of micellar conformation and electrostatic interaction. The ion species and ionic strength had significant influence on water content in the organic phase, and further changed the solubility of lysozyme in the organic phase. These were caused by the influence of salt ions on double diffuse-layer and repulsion of hydration membrane. Both reducing pH value and increasing surfactant concentration were all beneficial to solubility of lysozyme in the organic phase.

Study on Simultaneous Reaction and Separation of Vanillin Prepared from Isoeugenol by Enzymatic Conversion

WAGN Feng-shou;ZHAO Li-qing;SUN Zhi-hao

. 2005, 5(3): 273-276.

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There is product inhibition in the bioconversion from isoeugenol to vanillin by crude enzyme extracted from soybean. The product inhibition can be prevented effectively with the addition of resin HD-8. The optimum concentration of substrate is 1.5% (φ). With 150 g/L HD-8 added at the beginning, the vanillin concentration reached its maximum (3.41 g/L), corresponding to a molar conversion rate of 24.53%. As a result, the substrate and product can be separated efficiently. The yield of product and the recovery of substrate are 67.11% and 71.88% respectively.

Dimethyl Ether Synthesis from Biomass by Thermochemical Method

WANG Tie-jun;CHANG Jie;LU Hai-peng;FU Yan;LU Hao

. 2005, 5(3): 277-280.

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A Cu-Zn-Al/HZSM-5 catalyst was used for dimethyl ether (DME) synthesis from a synthetic gas containing nitrogen, which was produced by pine sawdust air-steam gasification combined with biogas reforming. The obtained N2-containing synthetic gas was used directly for DME synthesis. About 67% CO in a single run of conversion and 0.358 g/(g×h) (DME/catalyst per hour) yield could be achieved under the conditions of 280℃, 4 MPa and 1000~4000 h-1. Over 90% carbon content in the biomass could be converted to synthetic gas by reforming biomass fuel gas together with biogas (CH4). The maximum DME yield was 0.244 kg/kg (DME/biomass).

Determination of Trace Silicon in Nickel Sulfate Solution by Solvent Extraction

WEI Dai-cheng;YANG Ming-de;DANG Jie;ZHANG Jian-an;WU Yu-long

. 2005, 5(3): 281-284.

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For producing high-purity nickel material, silicon is one of the main impurities. To determine the trace silicon content is an exigent problem in industrial production. Test of heteromolybdate blue is the most popular method to analyze the silicon content, but for nickel sulfate solution, this method is limited because of color interference by Ni2+ ions. In this paper, the best conditions for the formation and extraction of heteromolybdate blue were studied. Iso-amyl alcohol was used as the extractant with a pH about 0.5 to extract heteromolybdate blue from nickel sulfate solution. Alkaline solution with pH over 12 was used as the stripping agent. Spectrophotometry was used to determine its absorbency after stripping. The experimental results showed that the absorbency had a good linear relation with the Si content. The analytic results are proved to be accurate, rapid and credible. The new analytical method can also expand to the silicon analysis of other colored solutions.

Rare Earth Extraction and Separation from Bastnaesite-Monazite Mixed Concentrate by Chemical Vapor Transport

ZHANG Li-qing;WANG Zhi-chang;LEI Peng-xiang;CHI Ming-yu;YANG Dong-mei

. 2005, 5(3): 285-288.

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Vapor phase extraction and separation of rare earth elements from bastnaesite-monazite mixed concentrate were investigated using chlorination and chemical vapor transport reaction mediated by vapor complexes LnAlnCl3n+3(Ln=RE elements). The non-rare earth elements P and Fe and Th were separated from the bastnaesite-monazite mixed concentrate by carbochlorination. At 1000℃ for 6 h, the resulting RE chlorides were chemically transported and separated with the vapor complexes while CaCl2 and BaCl2 remained in the residue. Significantly different CVT separation results were observed between operations with both gradually decreased and wavy temperature mechanisms. The highest transport amount and separation results appeared in the third receptor at a valley temperature.

Adaptability of Gold Leaching from Different Ores in Highly Stable Alkaline Thiourea Solutions

ZHENG Su;WANG Yun-yan;CHAI Li-yuan;ZHANG Xiao-fei

. 2005, 5(3): 289-294.

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In order to examine the flexibility of leaching different gold ores in alkaline thiourea system, six kinds of gold concentrates and calcines with different physical and chemical properties were chosen as objects, their chemical components and phases were analyzed, and the leaching behaviours were also investigated. The results indicated that stablizing reagents Na2SO3 and Na2SiO3 decreased the decomposition rate of alkaline thiourea solution greatly. However the stable effect of Na2SiO3 on alkaline thiourea was obviously better than that of Na2SO3 as well, and the decomposition rate of alkaline thiourea reduced from 72.5% to 33.8% with adding 0.3 mol/L Na2SiO3. K3Fe(CN)6 was the soft oxidizing reagent being suitable for alkaline thiourea system. The phases of gold ores were almost not changed before and after leaching in alkaline thiourea solution. There exist a large number of substances consuming alkali in the gold ores. During the leaching process, pH of the system dropped from 12.5 to 7.0 quickly, while the stablizing reagent Na2SiO3 could maintain pH of the system at about 12, which was propitious to the leaching process. The leaching rates of the coexisting metals in gold ores were less than 0.1% in alkaline thiourea system, which indicated that gold leaching in alkaline thiourea retained excellent selectivity. The alkaline thiourea system was suitable for leaching the pretreated oxidized gold ores in which the main phase was SiO2. The gold leaching rate reaching up to 82.68% suggests promising potential in commercial gold leaching processes.

Treatment of Waste Tyre Powder Using a High-frequency Capacitively Coupled Plasma Reactor

TANG Lan;HUANG Hai-tao

. 2005, 5(3): 295-300.

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A high-frequency (HF) capacitively coupled plasma reactor was developed to study the pyrolysis of waste tyre powder. The main objective was to generate a plasma at medium pressure and moderate temperatures for waste tyre powder gasification. Description of the reactor setup and experimental results concerning the plasma characteristics and product gas composition were presented, and potential use of the pyrolytic char was also discussed. Plasma temperatures were found to be between 1073 K to 1773 K, and under optimum operating conditions, over 70% of the tyre feed was converted into gaseous products by the treatment process. Pyrolysed gas was a mixture of H2, CO, CH4 and other organic compounds. The pyrolytic char may be used as low cost activated carbon for treating the species with large molecular weight.

Preparation of Cationic Water-based Polyurethane Emulsion

DING Cai-feng;HU Kong-cheng;XU Hong;OUYANG Ping-kai;ZHANG Shu-sheng

. 2005, 5(3): 301-304.

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A water-based cationic polyurethane emulsion was prepared. This emulsion was mainly composed of polyester glycol, trimethylol propane, toluene diisocyanate (TDI) and N-methyl-diethanolamine. The influences of the reaction temperature, content of each agent and stirring speed on the mechanical properties of the water-based polyurethane were investigated, giving its optimum composition. The polyurethane emulsion with good performance was prepared. And mechanical properties of the product are very good.

Study on the Function of Additive-PEG in the Preparation of Sb-doped SnO2 Nano-powder via Oxidative-coprecipitation

WEI Zhi-xian;OU Hai-feng;GONG Xi-jun;SUN Xin-jian;ZHU Zhen-xiao

. 2005, 5(3): 305-308.

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The function and the mechanism of additive PEG-6000 in the preparation process of Sb-doped SnO2 nano-powder via oxidative-coprecipitation have been studied by means of particle size analysis, IR spectrum, Zeta potential measurement, and sedimentation experiments. The suitable additive amount (0.8%～1.2%, ω) has been determined by means of sedimentation experiments, and viscosity measurements. The experimental results show that agglomeration of precursor is reduced by the steric effect of PEG-6000 adsorbing on it, and the powder product quality is greatly influenced by the added amount of PEG-6000. The well-dispersed Sb-doped SnO2 nano-powder can be obtained by adding suitable amount of PEG-6000 (0.8%～1.2%, ω). This process can be applied in the preparation of other nano-powders with precipitation method as well.

Effect of MnO2 Addition on Corrosion Resistance of Nickel-Ferric Spinel Based Inert Anode

JIAO Wan-li;ZHANG Lei;YAO Guang-chun

. 2005, 5(3): 309-312.

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The NiFe2O4 inert anode was synthesized by high temperature solid-state reaction sintering method using NiO and Fe2O3 as main raw materials and adding MnO2 powder. The static thermal corrosion rates of inert anode samples were measured by weightloss, and the corrosion mechanism was discussed. The experimental results indicate that the static thermal corrosion rate of the sample added with 2%(ω) MnO2 powder is the lowest. Because MnO2 dopant enriches at crystal boundary, the corrosion reaction of molten salt to crystal grains occurs firstly at the crystal grain boundary, and forms MnAl2O4 phase, which is dense and prevents the cryolite molten salt to penetrate into the inert anode, thus reducing the corrosion.

Structure and Properties of Metal-Nitride Bonded Corundum Slide Plate

BU Jing-long;YANG Xiao-chun;WANG Zhi-fa;WANG Rui-sheng;WANG Rong-lin;WANG Chun-mei;SUN Jia-lin

. 2005, 5(3): 313-316.

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The slide plate with 2% apparent porosity was prepared in a composition of 80%～90% tabular corundum and 20%～10% metal aluminum with nitridation (1100℃) and oxidation on the plate surface (800℃). The bending strength of this slide plate is up to 48.7 MPa at 1400℃, and its service life is two times as that of Al2O3-C slide plate when used in the process of pouring steel. Analysis of the plate microstructure shows that the plate density and strength can be increased, and excellent performance of erosion resistance to liquid steel can be obtained because of the volumetric expansion of AlN resulting from the nitridation of partial metallic aluminum and the effect of combining with corundum grains. High temperature plasticity state of some metallic aluminum, high heat conductivity of melting aluminum and aluminum nitride, multiphase thermal expansion coefficient mismatch of corundum and aluminum nitride are the main reasons why the material has high thermal shock resistance.

Emergy Analysis of Industrial Multi-product Systems

FENG Xiao;MIN Shu-ling;DAI Yu-li;LIU Yong-zhong

. 2005, 5(3): 317-321.

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Emergy analysis is a new analysis methodology, which can assess a system from the resource utilization and environmental effect. In this paper, the principles of emergy analysis, a new analysis method on energy consumption, are introduced. In order to extend the application range, the model of emergy analysis on industrial multi-product systems is established, based on the fundamental principles of energy conservation and emergy conservation. Joint indices and weighted average indices are proposed, which are designed with the aid of the energy consumption ratio used as the distribution coefficient. Joint indices give the indices for co-generation systems, while weighted average indices indicate the indices if each individual system produces one product. When joint indices are better than weighted average indices, the co-generation system is preferred. Two systems of heat and power co-generation for garbage burning are employed as a case study to prove the efficacy of the model, and compared with the traditional cogeneration system which uses coal as the fuel to show the advantages of emergy analysis.

Kinetics and Specific Growth Rate Control Strategy of Saccharomyces cerevisiae HYS98 Fermentation for High Productivity of SAM

ZHANG Yun-yi;LI Yuan-guang;JIN Jian;YANG Dong;SHEN Guo-min

. 2005, 5(3): 322-326.

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The fermentation kinetics of S-adenosyl-L-methionine (SAM) producing Saccharomyces cerevisiae HYS98 was studied through chemostat cultivation. The results showed that the relationship of biomass specific growth rate (μ) and residual sucrose concentration was in accordance with the Monod equation μ=μmaxCS/(KS+CS), where μmax=0.28 h-1, KS=1.27 g/L. The production of SAM followed the mathematical equation qSAM=-1.39μ2+0.19μ, when 0.005 h-1≤μ≤0.11 h-1. The sucrose consumption kinetics followed the equation qS=μ/0.62+0.012. To maximize the SAM productivity, a two-stage process control strategy was proposed based on the kinetic studies. By applying the strategy to the cultivation in a 5 L bioreactor, the accumulation of SAM reached 3.56 g/L and its production rate reached 0.15 g/(L·h) in 24 h, which was 67% increase over the highest level reported so far.

Fed-batch Fermentative Production of Glutathione by Candida utilis

WEI Gong-yuan;LI Yin;DU Guo-cheng;CHEN Jian

. 2005, 5(3): 327-331.

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The batch cultivation processes of C. utilis WSH 02-08 in a 7 L stirred fermentor for GSH production under diverse initial glucose concentrations were investigated. It was concluded that high concentration, high yield and high productivity of both yeast cell and GSH could not be consolidated in a batch process. Based on the results, the effects of different cultivation modes such as batch feeding, constant-rate feeding and exponential rate feeding on GSH production were also studied. High production of yeast cell and GSH were all realized in these cultivation modes of glucose feeding. As a whole, fed-batch culture with exponential rate feeding was the most suitable approach to attain high concentrations, high yields and high productivities of yeast cells and GSH in the cultivation of C. utilis WSH 02-08, under which the maximum DCW, GSH and intracellular GSH content reached 40.9 g/L, 857.2 mg/L and 2.25%, respectively, at the culture time of 48 h.

Process Characteristics of Bioleaching Meizhou Chalcopyrite by Thermophilic Acidianus brierleyi

SHI Xian-ai;LI Cong-ying;LIN Hui;MENG Chun;GUO Yang-hao

. 2005, 5(3): 332-336.

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The mechanism and characteristics of Meizhou chalcopyrite bioleaching by Acidianus brierleyi were studied. Adsorption of Acidianus brierleyi on the surface of ore was correlated with the Langmuir isotherm, the maximum adsorption capacity, XAm, was 5.00×108 cell/g, the adsorption equilibrium constant, KA, was 5.88×10-7 mL/cell. Bioleaching of Meizhou chalcopyrite by Acidianus brierleyi proceeded mainly with the direct bacterial oxidation. The bioleaching rate of copper solely by Acidianus brierleyi was 0.0137 g/(L·h), 6 times of the chemical oxidation rate of Fe3+. The bioleaching rate of Meizhou chalcopyrite by Acidianus brierleyi (65℃) was 16 times as that of Thiobacillus ferrooxidans (31℃). The optimal temperature of growth and leaching with Acidianus brierleyi was 65℃, the optimal pH of growth was 2.0, whereas the optimal pH of bioleaching was 1.5. Acidianus brierleyi would have a potential perspective in industrial application, as it could leach 91.3 percent of copper in Meizhou chalcopyrite within 10 days.

Addition of Menadione for Stimulating Catalase Accumulation by Thermoascus aurantiacus

WANG Ming-xing;LI Yin;FANG Fang;HUA Zhao-zhe;CHEN Jian

. 2005, 5(3): 337-340.

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The effect of menadione on the accumulation of CAT by Thermoascus aurantiacus was investigated. The experimental results indicate that addition of menadione helps to the accumulation of CAT. When 1 mmol/L menadione was added to fermentation liquor at 24 or 48 h, CAT activity in culture broth increased 11.0% and 23.1%, compared with that of control. CAT activity increased 32.5% when menadione was added at 36 and 48 h. CAT activity reached 1725 U/mL when 88 mmol/L hydrogen peroxide was added at 0 h and 1 mmol/L menadione was added at 48 h, which was 60.6% higher than that of control (1074 U/mL).

Preparation and Specific Molecular Recognition Properties of Human Hemoglobin Imprinted Polymers

SUN Rui-feng;LUO Hui;YU Hui-min;SHEN Zhong-yao

. 2005, 5(3): 341-344.

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Using acrylamide and methylacrylic acid as functional monomers, human hemoglobin molecular-imprinting-polymers (HHb-MIPs) were successfully prepared. The studies showed that the specific molecular recognition properties of HHb-MIPs were related to both the interactions between the functional groups of polymers and imprinted protein, and geometric complementation of the cavities in the polymers. Further studies showed that the content of methyacrylic acid in the polymers could affect the specific binding properties of MIPs. The supplementation of methylacrylic acid can increase the specific adsorption capacity of the HHb-MIPs on the one hand, but decrease the elution capacity on the other hand.

Bio-effect of Magnetic Field on Suspension-cultured Taxus chinensis var. mairei under Acid Stress

FAN Huan;SHANG Gui-min;YUAN Ying-jin

. 2005, 5(3): 345-348.

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The effect of direct current magnetic field (DCMF) on the cell growth and metabolism of suspension-cultured Taxus chinensis var. mairei under acid stress was examined. The experimental results showed that the ability of cell anti-acid stress, cell viability, biomass and intracellular protein were obviously enhanced by the DCMF. The viability of extracelluar PPO was enhanced, and accumulation of phenolics was restrained. Under certain HCl concentration, the higher the concentration of HCl, the stronger the bio-effect of the magnetic field. The obvious change of the medium pH and conductivity indicated that the ability of cell anti-acid stress was enhanced due to accelerated material transmembrane transportation by DCMF.

Effect of Different Types of Gas in Gas Stripping Ethanol Fermentation (GSEF)

ZHANG Jun;LIU Hong-juan;LIU De-hua

. 2005, 5(3): 349-352.

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The effect of air, CO2, N2 and pure N2 as stripping gas on the cell physiology and ethanol production in GSEF was studied. The experimental results indicate that different stripping gases have different effects on the cell growth as well as ethanol and glycerol production in GSEF. Aeration stimulated cell growth and glycerol production, and maintained cell count and viability, but decreased ethanol productivity. CO2 appeared to be inhibitory to yeast growth and decreased overall glycerol production. 99.5%～99.8% N2 was verified to be the best type of gas in GSEF, for ethanol and glycerol productivity increased respectively by 2 and 1.9 times than that of the control (fed-batch fermentation without gas stripping). Furthermore, study on pure N2 (99.999%) employed in GSEF showed that the rate of cell growth decreased greatly after 47 h of the fermentation. However, the cell count, viability and ethanol productivity could recover original levels when changing the stripping gas from N2 to air, and the data obtained proved that the final ethanol productivity increased by 1.3 times than the control.

Production of Ethanol by Simultaneous Saccharifiction and Fermentation from Cassava

LIU Zhen;WANG Jin-peng;ZHANG Li-feng;ZENG Ai-wu;YUAN Xi-gang

. 2005, 5(3): 353-356.

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The production of ethanol by simultaneous saccharification and fermentation (SSF), using cassava as raw material is presented. Through experiments under different conditions, the optimal technological conditions were obtained: cassava particle size below 0.45 mm, radio of cassava to water at 1:2.8, a-amylase and glucoamylase being 10 and 180 U/g respectively, and fermentation at 30℃ for 48 h. In comparison with the traditional production by separate hydrolysis and fermentation (SHF), it was found that SSF had many advantages, such as simple technology, low energy consumption, rapid fermentation and high concentration of ethanol, which is worthwhile to be explored and implemented in industry.

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