共查询到20条相似文献,搜索用时 15 毫秒
1.
Gyun Min Lee Chul Ho Kim Zainal Abidin Mohammed Yusof Moon Hi Han Sang Ki Rhee 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1987,38(4):235-242
Simultaneous saccharification and ethanol fermentation (SSF) of sago starch was studied using amyloglucosidase (AMG) and Zymomonas mobilis. The optimal concentration of AMG and operating temperature for the SSF process were found to be 0.5% (v/w) and 35°C, respectively. Under these conditions with 150 g dm?3 sago starch as a substrate, the final ethanol concentration obtained was 69.2 g dm?3 and ethanol yield, YP/S, 0.50 g g?1 (97% of theoretical yield). Sago starch in the concentration range of 100–200 g dm?3 was efficiently converted into ethanol. When compared to a two-step process involving separate saccharification and fermentation stages, the SSF reduced the total process time by half. 相似文献
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Dušanka J. Pejin Ljiljana V. Mojović Jelena D. Pejin Olgica S. Grujić Siniša L. Markov Svetlana B. Nikolić Milica N. Marković 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2012,87(2):170-176
BACKGROUND: Bioethanol produced from renewable biomass, such as sugar, starch or lignocellulosic materials, is one of the alternative energy resources that is environmentally friendly. Triticale crops have a high yield as well as a high starch content and amylolytic enzyme activity and are therefore considered to be ideal for bioethanol production. RESULTS: This study examined the feasibility of ultrasound pretreatment to enhance the release of fermentable sugars from triticale meal during pretreatment and consequently increase bioethanol yield in the simultaneous saccharification and fermentation (SSF) process by Saccharomyces cerevisiae yeast. Ultrasonic pretreatment effectively increased the glucose and maltose content after liquefaction by 15.71% and 52.57%, respectively, compared with the untreated control sample under determined optimal conditions of sonication (5 min, 60 °C). The ultrasound pretreatment consequently improved bioethanol production during SSF processing since the bioethanol content was increased by 10.89%. CONCLUSION: Taking into consideration significant process parameters obtained in the SSF process of triticale meal with ultrasound pretreatment at 60 °C, the process time may be reduced from 72 to 48 h. At that point of the SSF, maximum bioethanol content of 9.55% (w/v), bioethanol yield of 0.43 g g?1 of triticale starch, and percentage of the theoretical bioethanol yield of 84.56% were achieved. Copyright © 2011 Society of Chemical Industry 相似文献
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Masatoshi Matsumura June Hirata 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1989,46(4):313-326
A kinetic model for simultaneous saccharification and fermentation (SSF) of raw starch is proposed. The model includes the effect of ethanol on an active site for saccharification and the decay of a raw starch affinity site. The kinetic parameters were determined by using the experimental results of a batch saccharification and a long-term repeated-batch SSF of raw sweet potato starch. From analysis of the experimental results it is concluded that two subsites took part in ethanol inhibition, and that the inactivation of the raw starch affinity site was induced by adsorption of glucoamylase onto raw starch. The proposed kinetic model successfully predicted the progress of continuous SSF in a membrane reactor. 相似文献
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Yoshitoshi Nakamura Tatsuro Sawada Akihiro Komatsu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(10):1101-1106
In order to develop a method for converting raw starch into ethanol efficiently, direct fermentation of ozonized raw starch using a recombinant yeast was investigated. Ozonolysis was carried out as a pretreatment to convert raw starch into ethanol rapidly and efficiently, and then the effect of the ozone degradation conditions on the degree of polymerization and the amount of amylose in a raw starch was determined. Since the degree of polymerization was low and the amount of amylose was high, raw starch treated with an ozone concentration of 40 gm?3 and an ozonation time of 30 min was the material chosen for alcohol fermentation. Though the recombinant yeast could not convert the untreated raw starch, it converted the soluble starch and the ozonized raw starch at a comparatively high yield into ethanol. About 56% of the ozonized raw starch decomposed, and the ethanol concentration obtained from the ozonized raw starch was markedly greater than that obtained from untreated raw starch. The dynamic behavior of cell growth, substrate degradation, and ethanol production was examined in a continuous culture under various dilution rates, and the optimal dilution rate, ie 0.15 h?1, was determined for maximizing the ethanol productivity (amount of ethanol produced per unit time). © 2002 Society of Chemical Industry 相似文献
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木薯酒精渣的处置是制约木薯燃料乙醇大规模产业化的问题之一。本文立足于探索木薯酒精渣利用途径,分析了木薯酒精渣的主要成分,对比了氨水、氢氧化钠、氨水组合稀硫酸3种预处理方式对于木薯酒精渣纤维素和木素含量及纤维素酶水解效率的影响,分析了处理前后木薯酒精渣的表面结构及纤维素结晶度,并以氨水处理后的木薯酒精渣为底物,进行了同步糖化发酵。结果表明,3种预处理方法中组合预处理能更好地增加纤维素含量和提高纤维素酶水解效率,与未处理原料相比,组合预处理后纤维素含量增加了111.26%,木素下降了35.05%,酶水解72h纤维素转化率从42.10%增加到61.71%。氨水预处理后,原料的木素含量降低,处理后木薯酒精渣的表面变得更加粗糙,纤维素结晶度有所增加,以氨水处理后的木薯酒精渣为底物进行分批补料同步糖化发酵,当初始底物浓度为100.0g/L,分别在20h、40h、60h进行补料至最终底物浓度为400.0g/L时,发酵120h乙醇浓度达到51.0g/L。 相似文献
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蒸汽爆破麦草同步糖化发酵转化乙醇的研究 总被引:4,自引:0,他引:4
近年来对木质生物资源同步糖化发酵转化乙醇的研究较多,但是,麦草同步糖化发酵转化乙醇的最佳工艺条件还未确定。文中采用正交试验设计的方法,对在混合酶(纤维素酶Celluclast 1.5 1,β-葡萄糖苷酶Novozym 188)与酿酒酵母菌作用下,稀硫酸催化的蒸汽爆破麦草原料同步糖化发酵转化乙醇的工艺条件进行研究,详细讨论了反应温度、底物质量浓度、发酵液pH值、纤维素酶浓度对乙醇质量浓度和得率的影响。结果表明,工艺条件对乙醇质量浓度和得率的影响程度由高到低依次为:底物质量浓度、纤维素酶浓度、发酵液pH值、反应温度。最佳工艺条件为反应温度35℃,底物质量浓度100 g/L,发酵液pH值5.0,纤维素酶浓度30 FPU/g。在此条件下,随着反应时间的延长,乙醇质量浓度持续上升。反应72 h后,乙醇质量浓度和得率分别达到22.7 g/L和65.8%。 相似文献
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Peng LUO Zhong LIU Chuanmin YANG Gaosheng WANG 《Frontiers of Chemical Engineering in China》2008,2(4):447-451
Although simultaneous saccharification and fermentation (SSF) has been investigated extensively, the optimum condition for
SSF of wheat straw has not yet been determined. Dilute sulfuric acid impregnated and steam explosion pretreated wheat straw
was used as a substrate for the production of ethanol by SSF through orthogonal experiment design in this study. Cellulase
mixture (Celluclast 1.5 l and β-glucosidase Novozym 188) were adopted in combination with the yeast Saccharomyces cerevisiae AS2.1. The effects of reaction temperature, substrate concentration, initial fermentation liquid pH value and enzyme loading
were evaluated and the SSF conditions were optimized. The ranking, from high to low, of influential extent of the SSF affecting
factors to ethanol concentration and yield was substrate concentration, enzyme loading, initial fermentation liquid pH value
and reaction temperature, respectively. The optimal SSF conditions were: reaction temperature, 35°C; substrate concentration,
100 g·L−1; initial fermentation liquid pH, 5.0; enzyme loading, 30 FPU·g−1. Under these conditions, the ethanol concentration increased with reaction time, and after 72 h, ethanol was obtained in
65.8% yield with a concentration of 22.7 g·L−1.
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Translated from Chemical Engineering (China), 2007, 35(12): 42–45 [译自: 化学工程] 相似文献
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Experimental study on ethanol production from hydrothermal pretreated rapeseed straw by simultaneous saccharification and fermentation 下载免费PDF全文
Juan C. López‐Linares Inmaculada Romero Cristóbal Cara Encarnación Ruiz Eulogio Castro Manuel Moya 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2014,89(1):104-110
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Fumihisa Kobayashi Yoshitoshi Nakamura 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(9):985-994
A mathematical model for direct alcohol fermentation from starch was proposed using an amylase‐producing recombinant yeast, Saccharomyces cerevisiae SR93. This model consisted of the reaction rate equations for glucoamylase synthesis in the recombinant yeast, starch degradation by a glucoamylase, cell growth, production of glucose, and production of ethanol. The rate of glucoamylase synthesis was expressed on the basis of the diauxic growth model that represents catabolite repression and enzyme induction. The rate of starch degradation was expressed on the basis of the enzymatic hydrolysis model representing the change of structure resulting from starch degradation. The calculated values were in satisfactory agreement with the experimental data in a batch culture of direct alcohol fermentation from starch using S cerevisiae SR93. Furthermore, the calculated values obtained by changing only one parameter concerning the synthesis rate of glucoamylase were in satisfactory agreement with the experimental data using another recombinant yeast, S cerevisiae SR96. Copyright © 2003 Society of Chemical Industry 相似文献
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Mariana Lopes Cruz Miriam Maria de Resende Eloízio Júlio Ribeiro 《Chemical Engineering Communications》2018,205(6):846-855
This work studied the resistance of Saccharomyces cerevisiae Y904 to ethanol on an alcoholic fermentation process operated in fed-batch. The effect of temperature, inoculum size and substrate concentration on fermentation yield, productivity and residual sugars concentration was studied by a central composite design (CCD). Based on the CCD study, it was determined the optimum values of 240, 35?g/L, and 26°C for total reducing sugars, inoculum concentration and temperature, respectively. This set of conditions experimentally enabled a productivity of 6.0?g/L?h, a yield of 93% and an alcohol content of 113.6?g/L, after 10?h of fermentation. When yeast cells were adapted at 4°C, the inoculum pH adjusted to 2.5 and sugarcane broth used as substrate, a 94% yield and a 10.1?g/L.?h productivity were achieved. 相似文献
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Kerstin Hoyer Mats Galbe Guido Zacchi 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(4):570-577
BACKGROUND: The production of bio‐ethanol from softwood is considered a promising alternative to fossil fuels in Sweden. In order to make fuel ethanol economically competitive with fossil fuels, it is important to reduce the production cost, which can be done by increasing the dry matter content of the fermentation medium, thus reducing the energy demand in the final distillation of the fermentation broth. Running simultaneous saccharification and fermentation (SSF) at higher dry matter content has, however, been found to decrease the ethanol yield. RESULTS: The use of different stirrer types and stirring speeds in the present study has shown to have an influence on the final ethanol yield in SSF with 10% water‐insoluble solids (WIS). Also, higher concentration of pretreatment hydrolysate, i.e., with increased inhibitor concentration, at the same WIS resulted in a decreased ethanol yield. However, despite stirring problems and high inhibitor concentration, ethanol was produced at 12% WIS with an ethanol yield in the SSF step of 81% of the theoretical based on the content of fermentable sugars in the fermentor. CONCLUSION: The decrease in ethanol yield in SSF at high dry matter content has been shown to be a combined effect of increased mass transfer resistance and increased inhibitor concentration in the fermentation broth. Copyright © 2008 Society of Chemical Industry 相似文献
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在鞘氨醇单胞菌发酵生产威兰胶的实验中,为去除残余淀粉并准确测定发酵液中威兰胶的产量,比较了吸附法、酸解法、酶解法对威兰胶溶液和淀粉溶液的影响,并采用单因素实验和正交实验优化实验条件。结果表明,酸解法最优,最优条件为:p H=1.0,温度为95℃,时间为180 min,在此条件下,淀粉的去除率达到99.19%,威兰胶的保留率为87.51%。经碘量法验证:威兰胶-淀粉混合溶液在最优条件下酸解,淀粉的去除率和威兰胶的保留率与正交实验所得结果相符;该方法能准确测定含淀粉的发酵液中威兰胶的含量,误差在5%以内。 相似文献
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Nancy Bawa Devin Bear Gordon Hill Catherine Niu William Roesler 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(4):441-446
BACKGROUND: In North America, compared with sugar, starch is a more economical raw material to produce ethanol. Recently low temperature processing of starch granules directly to ethanol has been commercialized. With a view to minimizing process costs while maintaining a satisfactory ethanol yield, an inexpensive medium that does not require the addition of commercial α‐amylase has been developed for low temperature, direct fermentation of starch particles. RESULTS: Compared with an expensive medium that contained both yeast extract and α‐amylase, the inexpensive medium resulted in identical and 10% higher ethanol yields using glucose and starch granules as the raw substrates, respectively, but required longer processing times. Based on the different ingredient prices for expensive and inexpensive media, the operating cost to produce 10 million litres per year of ethanol utilizing simultaneous raw starch hydrolysis and fermentation is reduced over $ 2 million (Cdn) per year when using inexpensive medium. CONCLUSION: The new inexpensive medium and simultaneous raw starch hydrolysis and fermentation is considered the best strategy to produce ethanol directly from starch particles in North America. Copyright © 2009 Society of Chemical Industry 相似文献
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Some of the most recent, relevant, industrial and academic contributions made in the field of butanol production are reviewed here. The focus on butanol is due to the growing demand for non‐fossil biofuels. In addition, butanol can be mixed with fossil fuels or can be used alone, allowing an alternative to gasoline. Butanol can be synthesised biologically using sugars extracted from biomass such as agricultural waste. This agricultural waste must be pretreated before it is suitable for sugar extraction. Following this stage, enzymatic hydrolysis is employed, before performing fermentation using microorganisms. This article summarises some of the economical methods such as simultaneous saccharification and fermentation (SSF). Different pretreatment and saccharification processes were compared. Acid pretreatment and saccharification achieved the highest sugar concentrations from wheat straw. Monoethanolamine pretreatment achieved highest sugars from hardwood. Comparisons and analysis of different types of fermentation processes illustrated that immobilised reactor provided the best butanol rate of production. Integration of fermentation with product removal process improved butanol production in immobilised reactor. Gas stripping method was illustrated to be the product removal process. © 2011 Canadian Society for Chemical Engineering 相似文献
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Bioconversion of sludge from the primary clarifier of a sulphite pulping operation to ethanol offers a number of advantages over conventional disposal options. The amount of material which must be disposed of is reduced while, at the same time, salable and environmentally friendly fuel-ethanol is produced. In this study, primary clarifier sludge (PCS) was shown to be hydrolysed to produce fermentable sugars at a rate proportional to enzyme loading. Initial (1 hour) hydrolysis rates as high as 12.6 g reducing sugar/L · h were observed at an initial enzyme loading of 10 filter paper units (FPU)/g. Hydrolysis was inhibited by spent sulphite liquor (SSL), an inhibition which could be completely overcome by fermenting the SSL to remove sugars. Surfactants were found to only marginally improve the production of sugars. To reduce the deleterious effects of end product inhibition, single stage simultaneous hydrolysis and fermentation (SHF) was carried out using cellulase enzymes and Saccharomyces cerevisiae. 相似文献