固体酸催化酯交换制备生物柴油的研究进展

制备生物柴油最常用的方法是植物油和动物脂肪的均相碱或酸催化酯交换.与石油基柴油相比,从植物油和动物脂肪生产生物柴油的主要瓶颈是生产价格,特别是原料价格.为降低生物柴油成本,应利用廉价原料(如废油脂)、采用连续酯交换工艺并从生物柴油副产品(甘油)中回收高纯度甘油.均相酸催化剂虽反应产率高,但废催化剂会带来环境问题,故固体酸催化剂已成为目前研究热点.简述了固体酸催化酯交换制备生物柴油的研究进展和发展趋势,最后提出了一些建议.     

废食用油生产生物柴油技术研究进展

综述了利用废食用油生产生物柴油的方法、以及所使用的催化剂研究状况.以废食用油为原料生产生物柴油主要有3种方法:两步催化法,一步催化法和超临界法.环境友好的廉价的固体酸碱催化废食用油连续生产生物柴油是今后的发展趋势.     

离子液体介质中催化合成生物柴油技术研究

生物柴油作为一种可替代再生性清洁能源,成为新能源领域研究和开发的热点之一.廉价的原料、新合成工艺和高效催化剂技术是降低生产成本,促使该项技术推广应用的发展方向.离子液体作为一种功能可设计的新型绿色溶剂和催化剂,在化学反应和过程开发中显示出了独特的应用前景.将离子液体用于生物柴油制备是近年来新发展的方向,回顾了离子液体在...     

5-羟甲基糠醛制备生物基己二酸的研究进展

以5-羟甲基糠醛为原料制备生物基己二酸,可以避免以石油化工产品为原料制备己二酸工艺中存在的设备腐蚀、环境污染等问题,是更为绿色、环境友好的生产路线。5-羟甲基糠醛选择性氧化制备2,5-呋喃二甲酸是制备生物基己二酸的第一步,目前的研究主要围绕负载型贵金属(铂、金、钯、钌)催化剂展开,制备在无需外加碱的条件下能高效、稳定催化氧化反应的催化剂是该研究的发展方向。由2,5-呋喃二甲酸加氢制备2,5-二羧酸四氢呋喃,再加氢脱氧制备己二酸是制备生物基己二酸的第二步,可以采用两步法或一步法,开发高活性、高选择性的催化剂以促进四氢呋喃环断裂开环,是提高己二酸收率的关键。     

黄连木油脂基生物柴油的合成及其性能分析

以黄连木油脂为原料,对预酯化和酯交换两步法制备生物柴油的工艺进行了研究.通过正交实验,得出预酯化最佳工艺条件为:醇油摩尔比8∶1、催化剂加入量为0.8%、反应时间为3 h;酯交换最优工艺为:催化剂用量为0.6%、醇油摩尔比6∶1、反应时间为2 h、反应温度为50℃;此条件下制备的生物柴油得率达到92.3%;通过二聚化反应,所得生物柴油的主要性能指标均达到了国家标准GB/T 20828-2007.     

化学/酶复合催化法制备生物基化学品研究进展

化学催化与酶催化复合法制备生物基化学品可兼具生物催化剂的高效、高选择性和化学催化剂的稳定性(高温下)等优点,且原料易得、工艺简捷高效、环境友好,以化学/酶复合催化一步法反应制备糖醇、氨基酸和其他生物基化学品中的应用来阐述此方法的优势和意义,并对其在生物质炼制过程的应用进行了展望。     

化学/酶复合催化法制备生物基化学品研究进展

化学催化与酶催化复合法制备生物基化学品可兼具生物催化剂的高效、高选择性和化学催化剂的稳定性(高温下)等优点,且原料易得、工艺简捷高效、环境友好,以化学/酶复合催化一步法反应制备糖醇、氨基酸和其他生物基化学品中的应用来阐述此方法的优势和意义,并对其在生物质炼制过程的应用进行了展望。     

高酸值油脂制备生物柴油的方法研究现状

对以高酸值油脂为原料制备生物柴油的降酸工艺进行了研究,综述了酸碱法、两步法、酶催化和超临界法等相关技术,同时介绍了采用高酸值油脂为原料制备生物柴油的研究成果,并对它们各自的优缺点进行了分析,最后展望了高酸值油脂制备生物柴油的发展方向。     

环己烷氧化法合成己二酸用催化剂的研究进展

环己烷氧化制备己二酸是目前工业制己二酸的最传统、最广泛的工艺。其中环己烷一步法合成己二酸兼顾绿色环保和高效低成本等优势,是最有可能取代两步法合成己二酸的工艺,本文综述了以环己烷为原料一步合成己二酸的催化剂研究进展,并概述了各类催化体系合成方法的优缺点,同时提出了未来的催化剂研究方向。     

酵母菌为原料制备生物柴油工艺研究

以酵母菌为原料,KOH为催化剂,通过单因素实验,对影响传统两步法制备生物柴油的工艺条件,包括催化剂用量、衍生试剂用量、酯化时间进行考察。利用气相色谱-质谱联用分析平台对制得的生物柴油进行定性定量分析。结果表明,最佳工艺条件为:50 mg酵母菌干粉,KOH含量0.05 mol/L,甲醇用量400μL、酯化时间为3 h。生物柴油主要成分包括肉豆蔻酸甲酯、棕榈酸甲酯、十六烯酸甲酯、硬脂酸甲酯、油酸甲酯。     

Regeneration and Reutilization of Oil-Laden Spent Bleaching Clay via in Situ Transesterification and Calcination

Landfill bound waste from the oil palm industry, spent bleaching clay (SBC) containing significant amounts of adsorbed crude palm oil (CPO) has the potential to be used for biodiesel production. In this study, SBC was subjected to ultrasound-aided in situ transesterification with a co-solvent to convert the oil into methyl esters (biodiesel). Optimized reaction conditions used were 5.4 wt% KOH, methanol to oil mass ratio of 5.9:1 and 1:1 mass ratio of co-solvent (petroleum ether or ethyl methyl ketone) to SBC. The remaining bleaching clay was calcined at 500 °C for 30 min and reutilized for bleaching. Absence of –CH absorption peaks in the FTIR and TGA-FTIR analysis of regenerated clays shows the regeneration efficiency of the method. In situ transesterification and heat regeneration helped to restore pores without adversely affecting the clay structure. The use of ethyl methyl ketone (EMK) as the co-solvent in the in situ transesterification process produced clay with better bleaching qualities.     

生物柴油的生产技术

综述了生物柴油生产的原料、催化剂和生产工艺等相关研究进展。介绍了生物柴油的生产几乎可以采用所有的天然油脂作为原料，原料的来源对其性质有一定的影响。目前生物柴油工业化生产工艺主要是均相的酸、碱催化酯交换反应，很多都是在常压、低温下进行。均相酸碱催化剂的优点是反应转化率高，但是废催化剂会带来环境问题。非均相催化剂和酶催化剂则是目前研究的热点，固体碱、固定化酶等催化剂可以很容易从反应产物中分离出来。高温高压技术、超临界技术等被用于酯交换反应过程，反应可以在数分钟内完成。高速乳化技术、超声技术及微波技术等反应强化手段可以改善酯交换过程中的传质过程，有利于不完全互溶的醇油两相进行反应。     

分子氧一步法氧化环己烷合成己二酸技术进展

传统的环己烷两步法生产己二酸工艺过程复杂,反应条件苟刻,能量消耗较高,且产生大量有害的NOx气体,污染环境。而以分子氧为氧化剂、环己烷为原料一步法直接合成己二酸具有工艺流程短、氧化剂廉价易得、工艺绿色环保等优点,被誉为是最有希望实现己二酸绿色生产的技术之一。根据催化体系的不同从均相催化和多相催化两个维度概述分子氧一步法氧化环己烷合成己二酸的技术进展,内容涵盖可溶性金属催化法、有机小分子催化法、分子筛催化法以及负载金属催化法等,并对各合成方法的优缺点进行对比说明。     

负载型固体酸催化制备生物柴油研究进展

负载型固体酸催化剂具有无腐蚀、分离容易、对环境不产生污染、原料适应性广等优点,已成为制备生物柴油首选的绿色催化剂。本文综述了负载型固体酸催化剂制备原理、生产工艺、研究方法及其结构表征,分析了负载型固体酸自身结构与油脂酯交换反应催化活性的关系,预测了负载型催化剂在生物柴油制造业的应用前景。     

New process for catalyst-free biodiesel production using subcritical acetic acid and supercritical methanol

The production of glycerol as a by-product is unavoidable in the current conventional biodiesel manufacturing processes. Since biodiesel production is expected to increase in the near future, effective utilization of glycerol will become an issue of interest. In this study, therefore, a process consisting of subcritical acetic acid treatment to convert rapeseed oil to fatty acids and triacetin followed by conversion of the obtained fatty acids to their fatty acid methyl esters in supercritical methanol treatment was investigated. The obtained results clearly revealed that this two-step reaction could proceed effectively at a high reaction rate, and that fatty acid methyl esters and triacetin could be obtained under milder reaction condition than the one-step process utilizing supercritical methyl acetate and supercritical methanol.     

产油微生物利用废弃物积累油脂的研究进展

微生物油脂是一种应用前景广阔的新型油脂资源, 具有制备功能性油脂和生物柴油的优点, 因此越来越受到人们的重视。但微生物油脂生产时所用原料成本高, 导致微生物油脂的产业化发展受到制约。因此寻找廉价易得的发酵基质将促进微生物油脂生产的工业化进程, 同时解决了日益严峻的能源与环境安全问题。本文简述了各种工业废水、剩余活性污泥及餐厨废弃物等废弃物的特点, 总结了产油微生物利用该类废弃物生产油脂的研究现状及可能存在的发酵工艺及经济成本问题, 指出了未来的发展方向是开发附加值产品及廉价高效的絮凝剂以降低油脂成本、探究利用微生物前期处理降解剩余污泥中的毒性物质、探讨酶与酸碱联合水解餐厨废弃物的工艺等。     

Carbohydrate-derived Solid Acid Catalysts for Biodiesel Production from Low-Cost Feedstocks: A Review

Currently, most biodiesels are produced from virgin vegetable oils using a transesterification reaction. However, there are a number of other potential cheap sources for biodiesels, such as deep-frying oils/fats and palm fatty acid distillate (PFAD). PFAD is a lower-value by-product of the palm oil industry and is an economical source for biodiesel production. Due to the high cost of biodiesel production, the formulation of a new method to produce a cheaper biodiesel is imperative. Low-quality feedstocks (especially PFAD) using green and highly reusable catalysts have gained popularity due to their low production cost. High free fatty acids (HFFA) in the feedstock causes problems during the biodiesel production process, especially with the use of basic heterogeneous and homogenous catalysts. Recently, the effectiveness of a solid acid catalyst to catalyze biodiesel production from HFFA feedstock has caught the attention of researchers.

This comprehensive article explores the use of low-quality feedstocks and carbon-based catalysts for the conversion of a waste refinery crude palm oil product which contains a high percentage of FFA. The production and characterization of carbohydrate-derived solid acid catalysts are discussed, including their physico-chemical property measurements. Techniques used for the synthesis of biodiesels are also included. In addition, transesterification process variables such as the oil/methanol molar ratio, catalyst concentration, reaction time, and temperature are investigated. The final part of the article contains the combustion, emissions, and performance of produced biodiesels. Finally, conclusions, including perspectives and future developments, are also presented. The aim of this article is to demonstrate the current state of the use of low-quality feedstocks and green heterogeneous solid acid catalysts for the use in biodiesel production.     

麻疯树籽油生产生物柴油产业化

麻疯树籽油是具有潜力的生产生物柴油原料。介绍以麻疯树籽油为原料生产生物柴油的技术及所得生物柴油产品性质,分析麻疯树籽油组成对生产工艺选择的影响及与性质的关系,指出综合开发利用麻疯树资源可有效提高以麻疯树籽油为原料生产生物柴油的竞争力,与石化柴油或其它生物柴油混配使用可平衡性质优劣,现有的两步法转化工艺和高温转化工艺可以很好地解决麻疯树籽油生产生物柴油的工艺问题。     

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.     

Glucose-derived solid acids and their stability enhancement for upgrading biodiesel via esterification

Utilization of biomass-derived materials or chemicals plays a significant role in reducing the dependence of unsustainable resources of petroleum and coal. A series of sulfonated glucose-derived solid acids(SGSAs) were developed in this study through a one-step method. These catalysts were characterized by XRD, FT-IR, SEM,and BET to determine their physiochemical properties, and their acid content was measured by acid–base titration. The catalytic performances of SGSA catalysts were evaluated in two esterification reactions: propionic acid or oleic acid with methanol(a typical reaction to upgrade biodiesel). Conversion of oleic acid and selectivity of methyl oleate can reach as high as 93.3% and 94.7% respectively over SGSA-6, which has the highest -SO_3 H density. Moreover, regeneration of spent catalysts by sulfuric acid solution can significantly enhance their stability and reusability.