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我国发展生物燃料乙醇的长久大计 总被引:4,自引:1,他引:3
介绍了包括生物质能源在内的新能源开发和研究的迫切性和必要性,概述了第一代生物燃料乙醇遇到的危害粮食安全的问题,以及第二代生物燃料乙醇对于改变能源结构、保护生态环境、替代化石能源具有的前景和意义,并提出了我国发展第二代生物燃料乙醇的必要对策。 相似文献
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乙醇是全球使用最多的生物燃料.丰富的纤维素原料使生物燃料的生产具有很大的前景。生物质原料具有很多优点,但由于其韧性会导致工艺过程复杂并且成本昂贵。通过构造新纤维素水解酶体系、改造戊糖发酵工业中耐受抑制剂的酵母菌株以及结合最优一体化过程,显著改善了发酵工艺过程。中试试验为大规模研究做了基础。此文总结了近几年这一领域的研究进展,包括中试规模试验和生产过程对经济与环境的影响。 相似文献
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2012年我国进口石油超过60%,目前油价仍然较高;雾霾肆虐,汽车尾气导致的空气污染(PM2.5)严重危害人体健康。据此,文中建议生物燃料替代石油应作为国家优先能源战略。并提出现实发展1.5代生物燃料-甜高粱秆乙醇,加快研发和示范第2代生物燃料-纤维素乙醇和F-T生物柴油,加强第3代生物燃料微藻柴油研发,跟踪第4代生物燃料-人工光合燃料,以期减少进口石油、改善空气质量、拉动国内经济、创造就业机会、解决"三农"问题。 相似文献
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利用微生物生产生物燃料,其生产工艺要达到工业化生产还存在诸多问题。笔者综合叙述了发酵生产过程中遇到的生物质的预处理、生物燃料的提取纯化、微生物回收和胞内脂肪的提取等问题。 相似文献
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Graeme M. Walker 《Journal of the Institute of Brewing》2011,117(1):3-22
Global research and industrial development of liquid transportation biofuels are moving at a rapid pace. This is mainly due to the significant roles played by biofuels in decarbonising our future energy needs, since they act to mitigate the deleterious impacts of greenhouse gas emissions to the atmosphere that are contributors of climate change. Governmental obligations and international directives that mandate the blending of biofuels in petrol and diesel are also acting as great stimuli to this expanding industrial sector. Currently, the predominant liquid biofuel is bioethanol (fuel alcohol) and its worldwide production is dominated by maize‐based and sugar cane‐based processes in North and South America, respectively. In Europe, fuel alcohol production employs primarily wheat and sugar beet. Potable distilled spirit production and fuel alcohol processes share many similarities in terms of starch bioconversion, fermentation, distillation and co‐product utilisation, but there are some key differences. For example, in certain bioethanol fermentations, it is now possible to yield consistently high ethanol concentrations of ˜20% (v/v). Emerging fuel alcohol processes exploit lignocellulosic feedstocks and scientific and technological constraints involved in depolymerising these materials and efficiently fermenting the hydrolysate sugars are being overcome. These so‐called second‐generation fuel alcohol processes are much more environmentally and ethically acceptable compared with exploitation of starch and sugar resources, especially when considering utilisation of residual agricultural biomass and biowastes. This review covers both first and second‐generation bioethanol processes with a focus on current challenges and future opportunities of lignocellulose‐to‐ethanol as this technology moves from demonstration pilot‐plants to full‐scale industrial facilities. 相似文献
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Uroš Petrovič 《Yeast (Chichester, England)》2015,32(9):583-593
Economic growth depends strongly on the availability and price of fuels. There are various reasons in different parts of the world for efforts to decrease the consumption of fossil fuels, but biofuels are one of the main solutions considered towards achieving this aim globally. As the major bioethanol producer, the yeast Saccharomyces cerevisiae has a central position among biofuel‐producing organisms. However, unprecedented challenges for yeast biotechnology lie ahead, as future biofuels will have to be produced on a large scale from sustainable feedstocks that do not interfere with food production, and which are generally not the traditional carbon source for S. cerevisiae. Additionally, the current trend in the development of biofuels is to synthesize molecules that can be used as drop‐in fuels for existing engines. Their properties should therefore be more similar to those of oil‐derived fuels than those of ethanol. Recent developments and challenges lying ahead for cost‐effective production of such designed biofuels, using S. cerevisiae‐based cell factories, are presented in this review. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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杨木木片硫酸盐制浆前,进行缓和的碱抽提处理,抽提出半纤维素用作生物燃料(生物乙醇),在温度90℃,NaOH 1~2M,液比1∶4条件下进行碱处理,不需要高压设备,每吨木片得到半纤维素40~50kg,经碱抽提后木片进行硫酸盐蒸煮,与未经碱抽提木片参照对比,纸浆得率基本相同,但是需要很好地控制碱抽提与硫酸盐蒸煮工艺条件,能缩短蒸煮时间和节省化学品用量。碱预抽提木片得到的硫酸盐纸浆中纤维素/半纤维素的比率稍高,导致纸浆的抗张指数稍有降低(约10%),但是纸浆白度较高且筛渣含量低,为使硫酸盐纸浆的质量和得率保持较高水平,采用缓和的碱预抽提,使半纤维素得率较低,而回收的半纤维素的浓缩和离析比木片自水解或稀酸水解回收糠醛更加容易。 相似文献
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Imen Hamed 《Comprehensive Reviews in Food Science and Food Safety》2016,15(6):1104-1123
Microalgal biotechnology has emerged due to the health‐promoting properties of microalgae related to their bioactive compounds and the great diversity of products that can be developed from algal biomass. Microalgal biomasses have been produced industrially for applications in different fields such as food, pharmaceutical, nutraceutical, cosmetic, and animal feed industries. They can be cultivated either in open systems or in closed systems (photobioreactors). Another important area is the use of microalgal biomass for energy production. It has become obvious that petroleum‐derived fuels are unsustainable, due to depleting world reserves and greenhouse gas emissions. Microalgae can provide several different types of renewable biofuels. These include methane produced by anaerobic digestion of the algal biomass, biodiesel derived from trans‐esterification of microalgal lipids, bioethanol produced from carbohydrate fermentations, and photobiologically produced biohydrogen. The idea of using microalgae as a source of fuel is not new. However, it is now being taken seriously because of increases in petroleum prices and, more significantly, the increasing concern about global warming as associated with burning fossil fuels. This review offers an update on information about microalgae, specifically emphasizing their biotechnological importance. 相似文献
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冷冻饮品已纳入国家QS认证范围,生产企业必须通过QS认证才能生产和销售。在冷冻饮品的生产中,对于不同规模、不同产品品种(冰淇淋、雪糕、雪泥、冰棍、食用冰、甜味水)以及相应的工艺来说,归根到底是生产中产品的质量安全问题,主要问题有:生产工艺条件、设备的保养、生产过程的清洗、消毒、产品的贮存等。 相似文献
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Salim Ur-Rehman Zarina Mushtaq Tahir Zahoor Amir Jamil Mian Anjum Murtaza 《Critical reviews in food science and nutrition》2015,55(11):1514-1528
Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues. 相似文献
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二次发酵-苹果乳酸发酵(MLF)在葡萄酒生产过程中起非常重要的作用.酿酒需要选择合适的酿酒酵母和细菌,乳酸菌接种方案以及工艺条件控制系统.本文介绍了MLF发酵过程的优缺点、效益和技术缺陷.讨论了启动和运行MLF的方法及葡萄酒生产过程中各种微生物之间的相互作用.微生物主要是指酵母菌属中的酿酒酵母和酒类酒球菌属中的酿酒细菌. 相似文献
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