生物柴油的生产和应用

综述了生物柴油的发展历史和西方主要国家对生物柴油的研究、生产现状及有关的政策。讨论了各种生物柴油的制备方法及生物柴油应用的主要问题 ,对我国生物柴油的研究与开发提出了一些新的看法。     

我国生物柴油的研究现状分析

在总结生物柴油的原料、生产方法和研究动态的基础上,比较了几种常见植物油与矿物柴油的理化特性和各种生物柴油的生产方法的优缺点及生物柴油专利申请情况与柴油价格的关系,提出:(1)几种植物油的理化特性与柴油的相比存在一定差异,而植物油之间差异不大,它们用于生产生物柴油的研究方法可以相互借鉴;(2)生物柴油的研究形势与0#柴油的价格密切相关,就各种方法看,酯交换反应法是最受关注的方法;(3)生产生物柴油的方法各有优缺点,但酯交换反应法由于其适应性强、反应条件要求不高等,是目前最经济最有优势的方法,但此法仍需改进。     

生物柴油制备技术进展

文章概述了近年来国内外制备生物柴油技术,重点介绍了酸碱、生物酶及超临界工艺方法的研究进展,指出了影响我国生物柴油工业化发展的制约因素,提出了降低生物柴油生产成本的解决对策。     

欧洲生物柴油燃料及其原料的最新动向

在温室气体排放量逐年增多、大气污染越来越严重的今天,生物柴油作为真正的绿色柴油倍受全球关注。从能源安全、降低温室气体排放量等方面考虑,欧洲乃至全球正在加快生物柴油燃料的使用进程。介绍了欧洲生物柴油的生产情况、各种生物柴油的性质及制造方法,同时介绍了欧洲生产生物柴油所用的原料,最后提出了几点建议。     

欧洲生物柴油燃料及其原料的最新动向

在温室气体排放量逐年增多、大气污染越来越严重的今天,生物柴油作为真正的绿色柴油倍受全球关注。从能源安全、降低温室气体排放量等方面考虑,欧洲乃至全球正在加快生物柴油燃料的使用进程。介绍了欧洲生物柴油的生产情况、各种生物柴油的性质及制造方法,同时介绍了欧洲生产生物柴油所用的原料,最后提出了几点建议。     

生物柴油稳定性及稳定剂研究进展

综述了国内外生物柴油稳定性和生物柴油稳定剂的研究发展状况,内容涉及生物柴油的化学组成与基本特征、生物柴油的稳定性及其影响因素、生物柴油的稳定性检测及评价方法、生物柴油稳定剂的种类及性能等,认为添加稳定剂是提高生物柴油稳定性的主要手段。     

我国生物柴油产业化制备技术及其发展趋势

概述了我国生物柴油产业化发展现状,分析了我国生物柴油产业化技术发展缓慢的原因,介绍了提高生物柴油生产线经济效益的一些方法,预测了我国生物柴油产业化发展方向.结果表明,加快我国生物柴油适用技术的开发,制订相应的生物柴油进入市场的政策法规,是加速生物柴油产业化发展重要途径.     

探析生物柴油的制备及废水处理

当前生物柴油作为可再生且来源范围较广的可燃资源之一,其应用范围不断扩大,使社会各界对生物柴油的关注度有所攀升。为充分发挥生物柴油可再生、低污染、高应用率等优势,应加大生物柴油研究力度。本文总结了生物柴油的制备及废水处理方法,以满足充分发挥生物柴油应用优势的需求。     

国内外生物柴油研究生产现状及发展趋势

可替代柴油的生物柴油在国内外研究及生产的现状和发展趋势,指出了生物柴油的优势及生物柴油制备、应用中存在的问题,分析了发展生物柴油产业对我国石油安全、国民经济建设、农业产业结构调整和环境保护的作用,并展望了该产业的发展前景。     

生物柴油低温流动性及改进方法研究进展

综述了生物柴油低温流动性评价指标、主要影响因素及改进方法等相关研究进展。介绍了生物柴油中的脂肪酸组成和分布、酯基结构及杂质组成与生物柴油低温流动性能的关系。论述了改善生物柴油低温流动性的几种主要方法:加入添加剂法、改变生物柴油结构、冬化处理等。其中加入添加剂法成本低,操作方便,将成为改进生物柴油低温流动性能的研究方向。     

Hydroxyl content and refractive index determinations on transesterified soybean oil

Biodiesel, a promising alternative diesel fuel, is produced by transesterification of vegetable oils or animal fats with methanol. One of the main problems in the industrial application of the transesterification process is how to determine the conversion of oils to methyl esters. In this work, a quick analytical method was developed for monitoring the transesterification reaction of soybean oil with methanol. The conversion of oils to methyl esters could be determined by applying a simple linear correlation with hydroxyl content of the transesterified mixture or refractive index of the product. The results were in agreement with the values measured by ¹H NMR spectroscopy. Compared with existing chromatographic and other methods, this method for monitoring the transesterification of vegetable oils with methanol is simple, rapid, and inexpensive and is especially suitable for process control purposes.     

A Transesterification Double Step Process — TDSP for biodiesel preparation from fatty acids triglycerides

This study introduces a two consecutive steps basic–acid transesterification process, (denominated Transesterification Double Step Process — TDSP) for biodiesel production from vegetable oils. The process involves homogeneous consecutive basic–acid catalysis steps and is characterized by formation of well-defined phases, easy separation procedures, high reaction velocity and high conversion efficiency. The proposed TDSP is different in relation to other traditional two-step procedures which normally include acid esterification followed by basic transesterification, or enzymatic or even supercritical transesterification conditions. The biodiesel (fatty acid methyl esters) was analyzed by standard biodiesel techniques in addition to ¹H-NMR, indicating high quality and purity biodiesel products. The transesterification of sunflower and linseed oils resulted in oil conversions higher than 97% corresponding to yields of 85%. A probable reaction mechanism responsible for the process is presented.     

Evaluation of Transesterified Hardened and Liquid Soybean Oils as Raw Materials for Margarine Oils

Margarine oils have been prepared by transesterification of blends of hardened and liquid soybean oils or by blending of transesterified hardened oils with liquid soybean oil. The dilatometric characteristics of those oils and their nutritional values (as characterized by the L/S ratio of linoleic acid to total saturated acids) have been compared with the same parameters of margarine oils from local and foreign table margarines. It was concluded that margarine oils of suitable melting characteristics and of an average nutritional value (L/S ratio of about 0.70) can be prepared from blends of soybean oils alone, using transesterification process.     

Transesterification double step process modification for ethyl ester biodiesel production from vegetable and waste oils

In this study, the transesterification double step process (TDSP) was modified to enable the usage of ethanol as a transesterification agent in the production of biodiesel from vegetable and waste oils. The TDSP comprises a two-step transesterification procedure, which is initiated by a homogeneous basic catalysis step and followed by an acidic catalysis step. To optimize the transesterification parameters, different reaction mixtures and conditions were tested. Compared with methanol transesterification, larger ethanol and catalyst amounts as well as higher reaction times and temperatures were required. However, the results were consistent with those usually reported for ethanol transesterification. The obtained biodiesels (i.e., fatty acid ethyl esters (FAEEs)) were analyzed by standard physico-chemical techniques in addition to ¹H NMR, ¹³C NMR and FTIR spectroscopies, indicating high quality and purity biodiesel products. The obtained conversions were evaluated by ¹H NMR spectroscopy. For the optimized process, the triglyceride conversion to biodiesel was ?97% for all oils used. The overall process yields are considerably high when compared to the single basic catalysis yields.     

大豆油与甲醇酯交换反应体系的相平衡研究

生物柴油是一类清洁的可再生液体燃料,精炼植物油与甲醇酯交换是制备生物柴油的重要反应。针对目前难以准确获得酯交换反应体系的多组分相平衡组成等方面存在的问题,研究了间歇反应和连续逆流分离甘油等不同反应方式下大豆油与甲醇酯交换反应体系的多组分相平衡行为,并以三油酸甘油酯与甲醇酯交换为模型反应,采用UNIFAC和Modified UNIFAC模型进行了模拟计算。结果表明,在常压、60^oC反应条件下,在总组成偏离甲醇-甲酯二元组成的区域,UNIFAC和Modified UNIFAC模型准确计算了生物柴油酯交换反应体系的三元和四元相平衡组成。在甘油含量大于2.2%(质量)或转化率小于90%(质量)的酯交换反应中,计算值与实验值的平均偏差约为2%。酯交换反应相平衡的实验值和模型计算值表明,采用连续逆流方式分离甘油可以提高酯相中的甲醇含量,有利于传质和酯交换反应。这些结果为生物柴油工艺过程模拟、设备优化以及新技术开发提供了理论参考。     

超临界流体技术制备生物柴油的研究进展

概述了生物柴油的制备方法,即直接混合法、微乳法、热裂解法和酯交换法。重点介绍了酯交换法中的超临界制备方法的研究进展,对其制备方法、反应机理及动力学、各个因素对反应的影响进行了深入的阐述。     

Chemoenzymatic synthesis and characterization of urethane oils for surface coatings

Two-step chemoenzymatic synthesis of urethane oils has been studied. Initially, the partial esters were prepared by lipase-catalyzed transesterification of soybean and linseed oils with n-butanol. Partial esters were further reacted with different diisocyanates to obtain urethane oils. The composition of the partial esters was varied with reaction time in the transesterification step. Among all the lipases, the lipozyme was found to be the most suitable lipase for the transesterification reaction, yielding 80–85%. All of the urethane oils were of low molecular weights irrespective of the type of oil used in their preparation. Urethane oils, based on MDI, exhibited the best scratch resistance. All of the urethane oils showed good acid and alkali resistance and excellent solvent resistance. These oils also satisfactorily passed the impact resistance and the flexibility tests. Department of Chemistry, Vidyanagari, Mumbai-400 098, India.     

Biodiesel production from high FFA rubber seed oil

Currently, most of the biodiesel is produced from the refined/edible type oils using methanol and an alkaline catalyst. However, large amount of non-edible type oils and fats are available. The difficulty with alkaline-esterification of these oils is that they often contain large amounts of free fatty acids (FFA). These free fatty acids quickly react with the alkaline catalyst to produce soaps that inhibit the separation of the ester and glycerin. A two-step transesterification process is developed to convert the high FFA oils to its mono-esters. The first step, acid catalyzed esterification reduces the FFA content of the oil to less than 2%. The second step, alkaline catalyzed transesterification process converts the products of the first step to its mono-esters and glycerol. The major factors affect the conversion efficiency of the process such as molar ratio, amount of catalyst, reaction temperature and reaction duration is analyzed. The two-step esterification procedure converts rubber seed oil to its methyl esters. The viscosity of biodiesel oil is nearer to that of diesel and the calorific value is about 14% less than that of diesel. The important properties of biodiesel such as specific gravity, flash point, cloud point and pour point are found out and compared with that of diesel. This study supports the production of biodiesel from unrefined rubber seed oil as a viable alternative to the diesel fuel.     

生物柴油制备方法研究进展

生物柴油是典型"绿色能源",大力发展生物柴油对经济可持续发展,推进能源替代,减轻环境压力,控制城市大气污染具有重要的战略意义。本文论述了生物柴油各种制备方法,重点阐述了化学催化酯交换法、生物法以及超临界法制备生物柴油的研究进展,展望了生物柴油的发展前景。     

Advancements in development and characterization of biodiesel: A review

An ever increasing demand of fuels has been a challenge for today’s scientific workers. The fossil fuel resources are dwindling day by day. Biodiesel seems to be a solution for future. Biodiesel is an environmentally viable fuel. Out of the four ways viz. direct use and blending, micro-emulsions, thermal cracking and transesterification, most commonly used method is transesterification of vegetable oils, fats, waste oils, etc. Latest aspects of development of biodiesel have been discussed in this work. Yield of biodiesel is affected by molar ratio, moisture and water content, reaction temperature, stirring, specific gravity, etc. Biodegradability, kinetics involved in the process of biodiesel production, and its stability have been critically reviewed. Emissions and performance of biodiesel has also been reported.