生物柴油研究与应用现状

随着环境污染问题的日益严重和能源危机的日益紧迫,迫使人们急需寻找一种不仅清洁的、对环境友好的、而且可再生的能源.生物柴油的可再生性和清洁性引起了世界各国的重视.综述了生物柴油在国内外的生产应用现状、发展趋势以及发展生物柴油对我国的意义.并对生物柴油生产方法的研究进展进行详细的介绍,重点介绍了酯交换反应,对生物柴油目前还存在的问题进行了分析.     

酸催化合成生物柴油的研究现状

生物柴油生产过程中的催化剂是一个关键问题.目前,在生物柴油的规模化生产中碱催化和酸催化应用最为广泛.与碱催化相比,酸催化由于反应速度慢、所需反应条件苛刻而使其应用受到了限制,然而酸催化制备生物柴油的优点也是显而易见的.简述了在酸催化作用下将高酸值原料油转化为生物柴油的原理、酸催化工艺,主要介绍了国外从机理方面对酸催化剂的研究,涉及酯交换和酯化两个方面.最后对酸催化反应的影响因素以及仍存在的问题也稍加叙述.     

第二代生物柴油及其制备技术研究进展

以脂肪酸甲酯为代表组分的第一代生物柴油已经引起了人们广泛的兴趣,基于炼油厂加氢过程的生物柴油合成路线则形成了第二代生物柴油制备技术的核心.对第二代生物柴油制备过程的反应原理、工艺方法和技术路线进行了综述和讨论.     

生物柴油全生命周期资源和能源消耗分析

针对以菜籽油、麻疯树油和地沟油为原料制取生物柴油过程,应用生命周期评价方法,对原料种植、收集运输、原料预处理、生物柴油生产、产品配送等子过程的土地资源占用、水资源和能源消耗进行了计算,并对能量消耗进行了参数敏感性分析. 结果表明,3种原料生产1 t生物柴油占用土地资源分别为13132, 3333和5 m2,水资源消耗分别为9063.55, 12306.62和1.97 m3,化石能源消耗分别为0.9, 0.67和0.25 MJ. 由于水资源消耗和土地占用主要源于种植环节,能源消耗主要发生在种植和转化环节,在我国适合以地沟油和麻疯树油为原料生产生物柴油. 开发耐旱、高产、高含油率的油料植物品种和新型高效酯交换反应催化剂及优化反应工艺是降低生物柴油全生命周期资源占用和能源消耗的有效措施.     

生物柴油及生产概述

对生物柴油的产生背景、概念、成分、生产、以及生物柴油的标准等方面进行了概述,并对生物柴油在我国的应用前景进行了展望.     

超临界酯交换法制备生物柴油工艺基础及其过程强化技术研究

生物柴油以其优良的环境友好性和可再生性成为近年来的研究热点.简述了生物柴油的特性,比较了生物柴油制备工艺的优缺点,重点介绍了超临界甲醇法制备生物柴油的研究现状,指出以共溶剂和催化剂强化超临界过程可以有效地改善反应条件;同时对超临界甲醇法制备生物柴油的热力学和动力学进行了探讨,包括状态方程、混合体系临界参数、反应速率常数和反应活化能的估算方法;最后对超临界甲醇法制备生物柴油的经济性进行了分析.结果表明,超临界酯交换法具有与传统酸碱催化过程相当的竞争性,尤其是对以餐饮废油等低成本油为原料的生产过程.     

第二代生物柴油的最新研究进展

第一代生物柴油以脂肪酸甲酯为代表组分,在应用过程中还存在一些问题。以深度加氢生成脂肪烃为核心的第二代生物柴油生产技术近年来发展迅速。对不同工艺生产第二代生物柴油的反应原理、工艺过程和技术路线进行了综述和探讨。     

利用地沟油制备生物柴油技术的研究

本文提出了由地沟油生产生物柴油的新工艺,即在酸性催化剂(H_2SO_4)的作用先通过水解反应对地沟油进行预处理,然后进行酯化,将地沟油转化成生物柴油。探讨了醇油摩尔比、催化剂用量、反应温度和反应时间等工艺条件对生物柴油得率的影响。实验表明,最佳反应条件为:醇油摩尔比为5.3:1.催化剂(H_2SO_4)量为油的1.3%,反应温度65℃,反应时间为2小时,生物柴油得率高达90%.     

反应-分离集成工艺制备生物柴油研究进展

在全球性资源短缺、环境污染、生态破坏危机的背景下,生物柴油作为最易于应用和推广的绿色能源而深受研究部门和企业的青睐。相较于传统的生物柴油制备工艺,反应-分离集成工艺为生物柴油生产提供了新的技术和思路。本文综述了反应-分离集成技术制备生物柴油得最新研究进展以及应用效果,展望了生物柴油产业高效、绿色化生产方向。     

固定化脂肪酶催化酯交换制备生物柴油的研究进展

生物酶法生产生物柴油具有化学催化法不可比拟的优越性,是工业化生产的发展方向。介绍了固定化脂肪酶在催化油脂酯交换制备生物柴油方面的应用,对影响酯交换反应的脂肪酶源、底物摩尔比率、酰基受体、水含量、反应温度、副产物等因素进行了综述。     

生物柴油连续化生产设备及工艺进展

“碳中和”目标提出后，各行各业都在寻求减少碳排放的方法，生物质能源的使用是实现碳中和目标的重要手段之一。生物柴油以其优良的燃烧性能及环保性能成为一种较为理想的生物质燃料，其生产工艺是近年研究热点。连续化生产工艺对生物柴油的规模化制备与推广有着重要意义。目前连续化制备生物柴油的反应装置主要有微反应器、固定床反应器、管式反应器、膜反应器。本文综述了近年来国内外采用连续化工艺制备生物柴油的研究进展。这些研究表明，通过优化反应器结构、使用助溶剂、提高催化剂活性等均可提高生物柴油的收率。最后本文还分析了各反应器存在的不足，并提出了相应的建议，对生物柴油连续化生产进行了展望，以期为低成本、低能耗的生物柴油生产提供参考。     

废旧油脂的精制及酯交换制备生物柴油的研究

采用除杂、脱水、萃取、脱色等操作对废油脂如废煎炸油、地沟油、橡胶籽油进行了精制;对大豆油和精制处理前后的上述废油脂的各种物理化学性质进行了测定和评价;采用共沉淀法制备了Mg/Al类水滑石,450℃焙烧得到复合氧化物并以其催化各种油脂和甲醇合成生物柴油;分别用1H NMR法和仲裁法分析对比酯交换反应的产率。结果表明,大豆油制备生物柴油的产率高达96.9%,而精制后的地沟油、煎炸油和橡胶籽油制备生物柴油的收率分别达38.6%、40.2%和82.0%,可有效降低生物柴油生产成本。尤其是橡胶籽油,有望成为大豆油的替代原料用于生物柴油生产工业。     

Free Lipase-Catalyzed Esterification of Oleic Acid for Fatty Acid Ethyl Ester Preparation with Response Surface Optimization

Free lipase-mediated alcoholysis for biodiesel production has drawn increasing attention in recent years due to its advantages of lower cost and faster reaction rate compared to immobilized lipase. Ethanol, derived from renewable biomass, has a great potential for biodiesel production. A previous study showed that free lipase NS81006 could effectively catalyze the ethanolysis of triglycerides for biodiesel preparation. Since most crude plant oils always contain an amount of free fatty acids, oleic acid was used as the model substrate for this study on lipase-mediated esterification for biodiesel production. The central composite design of the response surface methodology was adopted for process optimization. A biodiesel yield of over 90 % was achieved under optimal reaction conditions and the repeated use of the free lipase was easily realized through phase separation either by natural gravity force or centrifugation.     

Process optimization design for jatropha-based biodiesel production using response surface methodology

Biodiesel of non food vegetal oil origin is gaining attention as a replacement for current fossil fuels as its non-food chain interfering manufacturing processes shall prevent food source competition which is expected to happen with current biodiesel production processes. As a result, non edible Jatropha curcas plant oil is claimed to be a highly potential feedstock for non-food origin biodiesel. CaO–MgO mixed oxide catalyst was employed in transesterification of non-edible J. curcas plant oil in biodiesel production. Response surface methodology (RSM) in conjunction with the central composite design (CCD) was employed to statistically evaluate and optimize the biodiesel production process. It was found that the production of biodiesel achieved an optimum level of 93.55% biodiesel yield at the following reaction conditions: 1) Methanol/oil molar ratio: 38.67, 2) Reaction time: 3.44 h, 3) Catalyst amount: 3.70 wt.%, and 4) Reaction temperature: 115.87 °C. In economic point of view, transesterification of J. curcas plant oil using CaO–MgO mixed oxide catalyst requires less energy which contributed to high production cost in biodiesel production. The incredibly high biodiesel yield of 93.55% was proved to be the synergetic effect of basicity between the active components of CaO–MgO shown in the physicochemical analysis.     

用于制备生物柴油的固体催化剂研究进展

简单介绍了生物柴油及其制备方法,重点综述了近年来国内外利用固体酸催化剂、固体碱催化剂制备生物柴油的研究进展和应用现状,并对生物柴油用固体催化剂的研究前景进行了展望。     

Techno-Economic Evaluation of Biodiesel Production from Waste Cooking Oil—A Case Study of Hong Kong

Fossil fuel shortage is a major challenge worldwide. Therefore, research is currently underway to investigate potential renewable energy sources. Biodiesel is one of the major renewable energy sources that can be obtained from oils and fats by transesterification. However, biodiesel obtained from vegetable oils as feedstock is expensive. Thus, an alternative and inexpensive feedstock such as waste cooking oil (WCO) can be used as feedstock for biodiesel production. In this project, techno-economic analyses were performed on the biodiesel production in Hong Kong using WCO as a feedstock. Three different catalysts such as acid, base, and lipase were evaluated for the biodiesel production from WCO. These economic analyses were then compared to determine the most cost-effective method for the biodiesel production. The internal rate of return (IRR) sensitivity analyses on the WCO price and biodiesel price variation are performed. Acid was found to be the most cost-effective catalyst for the biodiesel production; whereas, lipase was the most expensive catalyst for biodiesel production. In the IRR sensitivity analyses, the acid catalyst can also acquire acceptable IRR despite the variation of the WCO and biodiesel prices.     

超临界甲醇法制备生物柴油的动力学研究进展

超临界甲醇法制备生物柴油技术由于其独特的优势,从首次被提出以来,就受到国内外众多研究者的关注和研究。综述了超临界甲醇无催化制备生物柴油的相关动力学研究成果,讨论了反应机理、反应速率常数和活化能等,旨在阐明反应规律。另外也介绍了超临界流体二步法制备生物柴油技术及其动力学研究成果,并提出了这种技术的优势、存在问题及发展方向。     

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。     

A novel technique for separating glycerine from palm oil-based biodiesel using ionic liquids

Biodiesel production from abundant bio-sources has drawn the attention of the academic as well as the industrial communities in recent years. However, one of the most serious obstacles for using biodiesel as an alternative fuel is the complicated and costly purification processes involved in its production. The difficulties involved in the separation of glycerine and other un-reacted reactants and by-products necessitate the development of new competent low cost separation processes for this purpose. In this work, a low cost quaternary ammonium salt-glycerine-based ionic liquid is proposed as a solvent for extracting glycerine from the transesterification biodiesel product. The separation technique was tested on palm oil-based produced biodiesel with KOH as a reaction catalyst. The study investigated the effect of DES:biodiesel ratio and the DES composition on the efficiency of the extraction process. The lab scale purification experiments proved the viability of the separation technique with a best DES:biodiesel molar ratio of 1:1 and a DES molar composition of 1:1 (salt:glycerine). The purified biodiesel fulfilled the EN 14214 and ASTM D 6751 standard specifications for biodiesel fuel in terms of glycerine content. A continuous separation process is suggested for industrial scale application.     

Mixed methanol-ethanol technology to produce greener biodiesel from waste cooking oil: A breakthrough for SO4/SnO2-SiO2 catalyst

World energy crisis has become the foremost crucial topic in this new era. Unstable price of petroleum fuel in the world market and recent environmental concerns on gas emission during combustion have led to intensive search for alternative energy sources that are not only renewable but sustainable. Without doubt, one of the most important evolutions in the renewable energy sector is the development of biodiesel. Currently commercial biodiesel production is using methanol (non-renewable) as the main reactant to produce biodiesel due to its wide availability and low cost. However, biodiesel produced using methanol are not completely renewable as methanol can only be derived from petroleum fuel. Unfortunately, not much attention has been given on this issue. On the other hand, ethanol may emerge as a good solution to this problem as ethanol can be derived from renewable sources through fermentation process. The only constraint on the use of ethanol is its slow reaction rate in transesterification reaction and therefore resulted to energy inefficient biodiesel production process. Such limitations worsen if solid acid catalyst is used in the reaction. Thus, the aim of this present work is to introduce a simple mixed methanol-ethanol method to overcome these limitations and to produce biodiesel in a greener and sustainable manner. The effect of methanol to ethanol to oil molar ratio, reaction temperature, catalyst loading and reaction time towards biodiesel yield are discussed in detail. From this study, it was found that an optimum biodiesel yield of 81.4% can be attained at a relatively short reaction time of 1 h.