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燃料酒精生产中对木质纤维素稀酸水解液的脱毒处理 总被引:5,自引:0,他引:5
用稀酸水解农业废弃物秸秆、木材加工废物等木质纤维素产生糖,再将这些糖发酵成燃料酒精,是利用农林废弃物等生物质生产清洁燃料的途径之一。为使木质纤维素产生糖,通常采用理化结合的方法,在高温、高压和催化剂稀酸的作用下水解木质纤维素,例如,用稀酸140-160℃或者更高温度处理木质纤维素即可得到含糖水解液。在该水解过程中,虽然含有葡萄糖、木糖、阿拉伯糖等可发酵产酒精的混合糖,但由于反应条件剧烈,还会含有许多对酒精发酵微生物有毒性作用的抑制物,称之为发酵抑制剂,这些发酵抑制剂浓度随水解反应条件的剧烈程度和木质纤维素的种类不同而不同。水解液中的抑制剂主要有:糠醛、羟甲基糖醛、乙酸、酚类化合物、丁香酸、羟基苯甲酸、香草醛及其它有毒化合物。 相似文献
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混合菌群用于纤维素糖化和燃料酒精发酵的试验研究 总被引:2,自引:0,他引:2
采用刚果红纤维素平板法分别从田间腐烂的秸秆、潮湿地中的腐烂落叶内筛选出12株分解纤维素的菌株,分别进行了在不同温度、pH和时间条件下的羧甲基纤维素酶活(CMC)和滤纸酶活(FPA)的检测,筛选出了4株分解效率较高的菌株。采用正交实验研究了2株菌活性的主要影响因素,最终筛选出了2株产酶稳定的纤维素分解菌。采用扫描电镜,对菌株形貌进行了分析。应用2株纤维素分解菌和酵母菌混合菌种发酵的同时糖化发酵工艺,分别进行了单菌株和混合菌株的玉米秸秆糖化及燃料酒精发酵的试验研究,研究表明,混合菌群发酵后酒精产量为16g酒精/100g秸秆。 相似文献
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稻壳粉水解液发酵生产燃料酒精的研究 总被引:7,自引:1,他引:7
在试验室内分离、筛选、驯化培养出一株高效木糖酒精发酵菌株g-13,采用该菌株发酵稻壳粉水解液,可以同时将水解液中的葡萄糖和木糖转化为酒精,酒精转化率为0.38g/g(酒精/消耗的糖).该试验技术可操作性强,发酵条件易于控制.文章最后还对稻壳粉的水解条件进行了优化探索. 相似文献
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美、日利用纤维素生物质原料制燃料乙醇的技术开发 总被引:20,自引:0,他引:20
郭廷杰 《能源技术(上海)》2004,25(2):61-63
介绍了近年来美、日两国有关纤维素制乙醇技术的发展规划,以及相关技术研究开发的进程和所取得的成就。特别是,纤维素不能采用传统的发酵菌种直接发酵生产乙醇,采用硫酸水解法先把纤维素分解为低聚糖再发酵的工艺,采用纤维酶糖化纤维素的工艺都存在着产量低成本高的缺点有待改进。采用基因工程培育的具有纤维素酶基因的新酵种已引起世界各国研究者的关注。凝集性酵母在纤维素制乙醇的工业生产中已获得成功。 相似文献
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Technology for conversion of lignocellulosic biomass to ethanol 总被引:7,自引:0,他引:7
Current trends in production of fuel ethanol from lignocellulosic materials are reviewed. Particular emphasis has been laid on the microbial synthesis of cellulases, enzymatic hydrolysis, pretreatment of lignocellulosics, and their simultaneous saccharification and fermentation to ethyl alcohol. Some pilot-scale plants producing alcohol from biomass are also presented. 相似文献
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The decomposition of lignocellulosic raw material included: mechanical grinding of plant biomass, delignification (removal of lignin – this process was conducted in alkaline environment) and detoxification process (removal of alcoholic fermentation inhibitory compounds).The study on producing ethanol from corn straw was based on SSF method which involved conducting simultaneous enzymatic hydrolysis of cellulose and fermentation of obtained saccharides.Based on the study of corn straw alcoholic fermentation it was determined that the way of preparing the raw material in the initial stage of simultaneous saccharification and fermentation, significantly influences the improvement of fermentation yield.In comparison with an attempt in which biomass detoxification process was not implemented, the attempt with detoxification resulted in gaining higher fermentation yield and in lowering the content of aldehydes, methanol and furfural in the produced spirit.Moreover, in the attempts in which detoxification of raw material was used, better actual speed, productivity and the yield of alcoholic fermentation of corn straw was noted. The conducted detoxification in the process of lignocellulosic biomass decomposition improved fermentation yield. 相似文献
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介绍国内外以及上海的生物质生产燃料乙醇技术应用和发展现状,概述了燃料乙醇生产的生物质原料和生产方法,并分析了生产技术存在的主要问题。最后,提出了上海未来生物质燃料乙醇生产的发展方向。 相似文献
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Fuel ethanol is considered one of the most important renewable fuels due to the economic and environmental benefits of its use. Lignocellulosic biomass is the most promising feedstock for producing bioethanol due to its global availability and to the energy gain that can be obtained when non-fermentable materials from biomass are used for cogeneration of heat and power. In this work, several process configurations for fuel ethanol production from lignocellulosic biomass were studied through process simulation using Aspen Plus. Some flowsheets considering the possibilities of reaction–reaction integration were taken into account among the studied process routes. The flowsheet variants were analyzed from the energy point of view utilizing as comparison criterion the energy consumption needed to produce 1 L of anhydrous ethanol. Simultaneous saccharification and cofermentation process with water recycling showed the best results accounting an energy consumption of 41.96 MJ/L EtOH. If pervaporation is used as dehydration method instead of azeotropic distillation, further energy savings can be obtained. In addition, energy balance was estimated using the results from the simulation and literature data. A net energy value of 17.65–18.93 MJ/L EtOH was calculated indicating the energy efficiency of the lignocellulosic ethanol. 相似文献
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Juncus maritimus contains (41.5 ± 0.3)% cellulose and (31.34 ± 0.2)% hemicellulose on dry solid (DS) basis and has the potential to serve as a low cost feedstock for ethanol production. Dilute acid or freezing/thawing pretreatments and enzymatic saccharification were evaluated for conversion of halophyte plant from J. maritimus cellulose and hemicelluloses to monomeric sugars. The maximum concentration of released glucose from J. maritimus (53.78 ± 3.24) g L−1) by Freezing/thawing pretreatment and enzymatic saccharification (55 °C, pH 5.0 and 48 h) using CellicCTec2 from Novozymes and (49.14 ± 5.24) g L−1 obtained by dilute acid pretreatment. The maximum yield of ethanol from acid pretreated enzyme saccharified J. maritimus hydrolyzate by Saccharomyces cerevisiae strain was (84.28 ± 5.11)% of the theoretical yield with a productivity of (0.88 ± 0.16)g L−1 h−1. It was (90.87 ± 1.94)% of the theoretical yield with a productivity of (1.04 ± 0.10) g L−1h−1 for freezing/thawing pretreated plant and enzymatic hydrolysis by CellicCTec2. 相似文献
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A two-stage process using aqueous ammonia and hot-water has been investigated to fractionate corn stover. To maximize hemicelluloses recovery and purity in the liquid hydrolyzate by optimizing the fractionation process, the experiments were carried out employing response surface methodology (RSM). A central composite design (CCD) was used to evaluate and confirm the effectiveness and interactions of factors. The optimal fractionation conditions were determined to be as follow: (1) First-stage reactor operated in batch mode using a 15% NH4OH solution (wNH3 = 15%) at 1:10 solid:liquid ratio, 60 °C, and 24 h; (2) second stage percolation reactor operated using hot-water at 20 cm3 min−1, 200 °C, and 10 min.The model predicted 51.5% xylan recovery yield and 82.4% xylan purity under these conditions. Experiments confirmed the maximum xylan recovery yield and purity were 54.7% and 83.9% respectively under the optimal reaction conditions.With the solids resulting from the two-stage treatment, 87%-98% glucan digestibilities were obtained with 15 FPU of GC 220 per g-glucan and 30 CBU of Novo 188 per g-glucan enzyme loadings. Xylan digestibility of xylooligomer hydrolysates reached 76% with 8000 GXU per g-xylan of Multifect-Xylanase loading. In the simultaneous saccharification and fermentation (SSF) test using treated solids and Saccharomyces cerevisiae (D5A), 86 % to 98% of ethanol yield was obtained on the basis of the glucan content in the treated solids. 相似文献