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秸秆发酵燃料乙醇关键问题及其进展 总被引:1,自引:0,他引:1
利用木质纤维素原料生产燃料乙醇是国际公认的难题.本文从秸秆原料组分不均一性出发,分析了秸秆难以高值化原因;进一步分析了秸秆酶解发酵燃料乙醇的关键问题,介绍了有关秸秆原料预处理、纤维素酶生产、秸秆酶解发酵乙醇和产业化示范工程等的进展.秸秆酶解发酵燃料乙醇产业化示范工程具有自主知识产权,为实现我国秸秆转化燃料乙醇的规模化、产业化、低成本生产奠定了基础. 相似文献
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秸秆发酵燃料乙醇关键问题及其进展 总被引:2,自引:0,他引:2
利用木质纤维素原料生产燃料乙醇是国际公认的难题.本文从秸秆原料组分不均一性出发,分析了秸秆难以高值化原因;进一步分析了秸秆酶解发酵燃料乙醇的关键问题,介绍了有关秸秆原料预处理、纤维素酶生产、秸秆酶解发酵乙醇和产业化示范工程等的进展.秸秆酶解发酵燃料乙醇产业化示范工程具有自主知识产权,为实现我国秸秆转化燃料乙醇的规模化、产业化、低成本生产奠定了基础. 相似文献
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秸秆发酵燃料乙醇关键问题及其进展 总被引:3,自引:0,他引:3
利用木质纤维素原料生产燃料乙醇是国际公认的难题。本文从秸秆原料组分不均一性出发,分析了秸秆难以高值化原因;进一步分析了秸秆酶解发酵燃料乙醇的关键问题,介绍了有关秸秆原料预处理、纤维素酶生产、秸秆酶解发酵乙醇和产业化示范工程等的进展。秸秆酶解发酵燃料乙醇产业化示范工程具有自主知识产权,为实现我国秸秆转化燃料乙醇的规模化、产业化、低成本生产奠定了基础。 相似文献
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由于能发挥缓解能源紧张、减少环境污染、促进农村发展等重要作用,利用年产量巨大的植物纤维资源,生产可再生性液体替代燃料乙醇的技术受到了巨大的关注,成为工业生物技术的研究热点.酶法生产纤维素乙醇面临多种困难:纤维素原料比重轻,收集运输不便;原料结构复杂,需要深度预处理;纤维素酶系的酶解效率有待提高;半纤维素中的木糖难以发酵转化为乙醇等.经过多年研究,新技术已经取得重大进展,开始接近实用化.紧迫的社会需求正在迫使国内外政府和企业界大量投资,开展纤维素乙醇的中试研究和试生产,力求在短时期内克服上述难点,尽快实现产业化.充分利用植物纤维资源中的多种组分,联合生产乙醇和部分高值产品的生物精练技术,是实现纤维素乙醇产业化的重要突破口和必然途径.玉米芯生物精练生产乙醇和木糖相关产品的技术正在进行产业化.本文综述了纤维素乙醇产业化的研究进展并做了展望. 相似文献
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The conversion of biomass into ethanol using fast, cheap, and efficient methodologies to disintegrate and hydrolyse the lignocellulosic
biomass is the major challenge of the production of the second-generation ethanol. This revision describes the most relevant
advances on the conversion process of lignocellulose materials into ethanol, development of new xylose-fermenting strains
of Saccharomyces cerevisiae using classical and modern genetic tools and strategies, elucidation of the expression of some complex industrial phenotypes,
tolerance mechanisms of S. cerevisiae to lignocellulosic inhibitors, monitoring and strategies to improve fermentation processes. In the last decade, numerous
engineered pentose-fermenting yeasts have been developed using molecular biology tools. The increase in the tolerance of S. cerevisiae to inhibitors is still an important issue to be exploited. As the industrial systems of ethanol production operate under
non-sterile conditions, microbial subpopulations are generated, depending on the operational conditions and the levels of
contaminants. Among the most critical requirements for production of the second-generation ethanol is the reduction in the
levels of toxic by-products of the lignocellulosic hydrolysates and the production of low-cost and efficient cellulosic enzymes.
A number of procedures have been established for the conversion of lignocellulosic materials into ethanol, but none of them
are completely satisfactory when process time, costs, and efficiency are considered. 相似文献
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Ethanol can be directly blended with gasoline, reacted with isobutylene to form the oxygenated fuel additive ethyl tert-butyl
ether (ETBE), or burned directly as a neat fuel. Blends of either ethanol or ETBE with gasoline force engines set for gasoline
to run lean and can substantially reduce carbon monoxide emissions. ETBE also lowers the overall vapor pressure, thereby cutting
back on smog-forming emissions. Neat ethanol further reduces smog formation since it has a low volatility, the photochemical
reactivity of ethanol and its combustion products is low, and low levels of smog producing compounds are formed by ethanol
combustion. Neat ethanol also offers good engine performance owing to its high heat of vaporization, high octane, and low
flame temperature.
Fermentation stoichiometry reveals that many feedstocks are expensive for fuels production even considering coproduct credits
and ignoring conversion costs, whereas lignocellulosic feedstocks cost much less than their value. Furthermore, the quantities
of lignocellulosics are projected to be ample even for neat ethanol production. Release of carbon dioxide during fermentation
concentrates almost all the heat of combustion from the solid carbohydrate portion in liquid ethanol. Since the carbon dioxide
released during production and use of ethanol is recycled during growth of biomass, ethanol utilization doesn’t contribute
to the accumulation of carbon dioxide in the atmosphere and possible global warming. 相似文献
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秸秆生产乙醇预处理关键技术 总被引:1,自引:0,他引:1
乙醇是一种很有希望替代有限石油的燃料.目前燃料乙醇已在我国部分省市得到应用.我国目前燃料乙醇生产的主要原料是陈化粮,但我国陈化粮可用于燃料乙醇生产的量十分有限.真正可大量转化乙醇的应是纤维质材料.纤维质材料转化乙醇的挑战性问题是产量偏低、成本偏高.纤维质材料的预处理是转化乙醇过程中的关键步骤,该步骤的优化可明显提高纤维素的水解率,进而降低乙醇的生产成本.本文总结了纤维质材料预处理的各种方法,对各种方法的优缺点进行了综述和分析,并对生物质预处理技术发展的前景进行了展望. 相似文献
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生物质半纤维素稀酸水解反应* 总被引:7,自引:0,他引:7
半纤维素是木质纤维素类生物质中第二大组分,半纤维素的高效、低成本转化是实现木质纤维素类生物质转化工艺实用化的一个技术关键。稀酸水解技术被广泛应用于水解生物质半纤维素,其对半纤维素糖的转化率高,得到的糖可进一步发酵生产燃料乙醇等。半纤维素还可直接水解制低聚糖等功能性食品和糠醛等化工产品。本文综述了半纤维素稀酸水解反应的研究进展。介绍了半纤维素的基本结构特征,解析了稀酸催化半纤维素水解的反应机理及反应网络,评述了半纤维素水解过程中反应条件等对目标产物的影响,并总结了半纤维素稀酸水解动力学模型。在此基础上,对今后半纤维素稀酸水解反应的研究方向与水解产物的利用进行了展望。 相似文献
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Xiaolin Luo Yanding Li Navneet Kumar Gupta Bert Sels John Ralph Li Shuai 《Angewandte Chemie (International ed. in English)》2020,59(29):11704-11716
Selective and economic conversion of lignocellulosic biomass components to bio‐based fuels and chemicals is the major goal of biorefineries, but low yields and selectivity for fuel precursors such as sugars, furanics, and lignin‐derived monomers pose significant disadvantages in process economics. In this Minireview we summarize the existing protection strategies used in biomass chemocatalytic conversion processes and focus the discussions on the mechanisms, challenges, and opportunities of each strategy. We introduce a concept of using analogous methods to manipulate biomass catalytic conversion pathways during the upgrading of carbohydrates to fuels and chemicals. This Minireview may provide new insights into the development of selective biorefining processes from a different perspective, expanding the options for selective conversion of biomass to fuels and chemicals. 相似文献
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Applied Biochemistry and Biotechnology - Although lignocellulosic biomass and wastes are targeted as an attractive alternative fermentation feedstock for the production of fuel ethanol, cellulosic... 相似文献