我国发展生物燃料乙醇的长久大计

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。     

木质纤维素乙醇的新进展

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。     

生物燃料产业发展路线图

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。     

粮食vs.燃料中国粮食不能承受"燃料化"之重

1 生物燃料乙醇的现状 1.1 迅速发展的生物燃料乙醇产业 在世界石油价格持续上涨和环境问题的背景下,同时作为剩余农产品处理的对策之一,近十年来,世界各国的生物燃料乙醇生产有了快速的发展(图1).     

木质纤维素转化燃料乙醇研究现状与前景(上)

纤维素生物转化燃料乙醇对解决当前世界能源危机、粮食短缺和环境污染等问题具有重要意义,已成为当前研究的热点.本文综述了国内外利用纤维素原料发酵生产酒精技术的研究概况.从纤维素原料的预处理方法,发酵工艺研究、菌种的合理运用与改造等方面分别作了介绍.制约燃料乙醇发展的因素主要是成本问题,本文提出,以生物炼制的要求开展纤维素的研究与开发利用,降低工业化生产的成本.     

甜菜乙醇实现工业化生产

<正>将甜菜洗净磨浆后加入一种生物酶与渣料一同发酵,蒸馏,最后产出高纯度乙醇。一项利用生物技术生产非粮食类生物乙醇工艺取得重大突破。香港和宝国际控股有限公司设在宁夏银川的生产示范基地两年的工业化生产实践证明,利用非粮食原料、低成本生产生物燃料乙醇巴成为可能。燃料乙醇是乙醇汽油的主要原料,由于是植物生产,因此被称为生物质可再生能源。按照"十一五"专项规划要求.燃料乙醇年产量要达到500万t。全国80%以上地区全部要封闭强制添加乙醇汽油。但是,直到2007年,我国燃料乙醇产量还仅为100多万t。     

大型藻类发酵燃料乙醇的研究进展

大型海藻发酵燃料乙醇已成为目前生物乙醇研究的前沿热点,大型海藻具有生长周期短、资源丰富、不与粮争地等优点,发展前景广阔。该文综述了大型藻类发酵燃料乙醇的预处理方法、水解糖化以及发酵工艺的研究进展,并对其发展趋势进行了展望。利用大型藻类发酵生产燃料乙醇对缓解人类面临的粮食、能源和环境三大危机具有重要意义。     

利用纤维素原料生产燃料酒精的研究进展

介绍了近年来美、日两国关于纤维素制乙醇技术的发展情况。燃料乙醇的应用意义及现状。综述了纤维素原料生产乙醇的预处理及水解为葡萄糖技术的研究进展 ,介绍了纤维素原料发酵生产酒精技术的概况 ,对不同的预处理、水解和发酵方法进行了比较     

生产生物燃料的技术难题

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。     

玉米秸秆发酵生产燃料酒精工艺探讨

本文介绍了一种发酵玉米秸秆生产燃料酒精的新工艺 ,将传统的利用同时糖化发酵法生产乙醇的一步发酵法改为利用固态发酵与液态发酵并行的两步发酵法 ,有效地解决了一步发酵过程中的水解产物对发酵的抑制问题。此外 ,文章还对工艺流程的控制进行了合理化分析。     

125th Anniversary Review: Fuel Alcohol: Current Production and Future Challenges

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.     

用木材生产生物燃料与纸浆

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。     

Next‐generation biofuels: a new challenge for yeast

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.     

The Evolution and Versatility of Microalgal Biotechnology: A Review

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.     

冷冻饮品生产中几个应注意的问题

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。     

Xylitol: A Review on Bioproduction,Application, Health Benefits,and Related Safety Issues

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.     

面向注塑模CAE的有限元网格自动生成技术

研究了面向注塑模CAE的有限元网格自动生成技术。提出基于映射修正因子的二次参数映射法,详细阐述了参数映射过程中两种映射修正因子的定义和计算方法,利用该映射法实现了模型表面的三角网格剖分。采用数据交换标准STEP作为注塑模CAE软件与各类CAD系统的衔接接口,实现模型的导入和重建。将模型的每个表面和边界曲线映射至参数空间,利用推进波前法生成参数面网格,然后映射回三维表面。     

苹果乳酸发酵生产葡萄酒

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.     

国外利用生物技术对麦糟进行高值化开发利用的新进展

近年来国外在废弃麦糟的增值化开发利用方面主要是利用生物技术转化生产各种微生物产品,尤其是生物乙醇、乳酸、木糖醇、阿魏酸及一系列微生物酶等.生物乙醇方面,主要对麦糟的预处理工艺、发酵条件进行优化,超声波、非热等离子体等手段被引入麦糟的预处理环节;连续发酵法、整合生物处理法(CBP)等则被引入发酵环节,普遍提高了乙醇产量或...     

不同预处理方式对玉米秸秆酶解液成分的影响

玉米秸秆中的单糖或者寡糖的释放由于芳香族聚合物木质素阻遏纤维素酶进行糖解聚作用而效率地下.然而预处理作用可以有效地移除木质素或者打破木质素的结构,从而可以增强还原糖的释放.其过程主要包括2个生物转化程序:玉米秸秆中纤维素的水解产生还原糖,然后进行生物乙醇发酵生产过程.在该研究中,通过HPLC方法监测不同预处理方法处理玉米秸秆酶水解液中的成分,从而得到最佳的预处理方法.结果表明,磁力搅拌辅助CO2激光协同通气预处理方法的糖化效果高于其他预处理方法.