生物柴油制备以及在柴油机上应用的关键技术研究

针对工业上生产生物柴油的制备技术、工艺流程、酯交换反应影响因素、质量指标以及在柴油机上燃烧的关键技术等进行了综述。国内外仍然以酯交换法反应为主,且常以氢氧化钠等碱为催化剂。如何降低生物柴油中甲醇、甘油、水含量以及研制适用于生物柴油的抗氧化剂均是生物柴油应用的关键技术。关于多种生物柴油的掺混燃烧以及燃用生物柴油导致的排放对于生物系统的细胞毒害性和突变性等涉及人类健康影响的研究仍然有待加强。     

生物柴油转化的微分动力学模型及其应用

根据油脂醇解反应特征给出了生物柴油生产过程中的反应动力学方程,利用软件Maple给出了动力学方程的数值解法以及预测反应过程中各物质浓度的变化情况的仿真计算程序。利用这种方法,结合生物柴油转化和过程分析的试验,分析了生物柴油转化中的动力学模型,结果表明微分动力学模型可用来预测生物柴油的生产中酯交换反应的速率,可以指导最佳工艺条件的确定。     

酯交换法制备生物柴油反应机理和影响因素分析

阐述了生物柴油的生产制备技术,从生物柴油酯交换合成反应出发,探讨了各种酯交换反应的反应机理;从原料油中的水分、游离脂肪酸、温度、压力、催化剂、反应时间、醇油比和原料混合程度等各个方面分析了对生物柴油制备的影响,得出了最佳的反应工艺条件。     

水力空化强化高芥酸菜籽油联产生物柴油和芥酸甲酯

水力空化条件下,以高芥酸菜籽油为原料,研究了醇-油不相溶体系的酯交换反应.结果表明:水力空化技术能大大缩短酯交换反应达到平衡的时间;与机械搅拌反应体系相比,在反应温度60℃、醇油摩尔比6∶1、催化剂用量1.0％ KOH的条件下,反应平衡时间可从60min缩短至30min,油酯的转化率从94％提高到99％,水力空化技术可强化醇油互不相溶体系酯交换反应传质过程,是一种高效的生物柴油制备方法.同时通过实验以高芥酸菜籽油为原料制备出高品质的生物柴油和高附价值的芥酸甲酯,为我国发展菜籽油生物柴油降低生产成本提供新思路.     

甲醇/乙醇均相体系酯交换制备生物柴油的研究

为解决酯交换反应中甲醇与植物油呈两相不互溶的问题,研究了在甲醇/乙醇均相体系中,植物油在NaOH催化剂条件下通过酯交换反应制备生物柴油的工艺.结果表明,添加乙醇能有效提高反应速率.通过Box-Benhnken试验,得到最佳工艺条件:反应温度为48.2℃、催化剂用量为植物油质量的0.59%、反应时间为25.4 min.在此工艺条件下,生物柴油转酯化率为99.3%,产品的主要性能指标符合我国生物柴油标准(GB/T20828-2007).     

蓖麻油制备生物柴油的研究

研究了以蓖麻油为原料,采用化学酯交换方法制备生物柴油的工艺过程.测定了最佳反应条件：催化剂用量为油重的1.0%,甲醇用量为油重的20%,反应温度为65℃,反应时间为90 min,酯交换率可达到86%.     

植物油制备生物柴油的研究

以植物油为原料，在催化剂（KOH）的作用下，通过甲醇酯交换反应生成脂肪酸甲酯即生物柴油的试验研究，考察了醇油比、催化剂用量、反应温度、反应时间等反应条件的变化对植物油转化率和产品纯度的影响。     

小桐油制备生物柴油的研究

实验研究了以小桐子油为原料，采用循环气相酯化-酯交换-水蒸气蒸馏法制备生物柴油的工艺过程。着重研究了降低原料酸值以及酯交换过程的优化条件。试验结果表明。气相酯化法可在很短的时间内将原料的酸值降到酯交换对原料的酸值要求；酯交换反应的最佳操作条件为：甲醇用量为油重的20％，催化剂用量为油重的1％左右，反应温度为60—70℃，反应时间为90—120min。     

制备生物柴油所用催化剂的研究进展

生物柴油作为一种清洁的可再生能源,可以由动植物油脂通过酯交换反应来制备.本文概述了近年来制备生物柴油的多种催化剂,并探讨了各自的优点及缺陷.     

橡胶籽油制备生物柴油的工艺研究

实验研究了乙醇钠催化下橡胶籽油与乙醇进行酯交换反应制备生物柴油的工艺条件。通过正交实验和单因素实验,发现酯交换反应的最佳工艺条件:催化剂用量为油重的1.0%,醇油物质的量比为15∶1,反应温度为78℃,搅拌时间为120 min,在此反应条件下,橡胶籽油转化率为92.14%。     

Optimization of transesterification process parameters of castor oil ethanolysis using response surface methodology-based genetic algorithm

Castor oil is unusual oil that is predominantly composed of ricinoleic acid. In the present study, castor oil biodiesel was produced from castor oil with bio-alcohol (ethanol) via a transesterification process. Also, this study investigates the influence of transesterification process parameters, i.e., reaction temperature, catalyst (sodium ethoxide) concentration, and ethanol:castor oil molar ratio on the yield of castor oil ethyl ester. The experiments are carried our as per a central composite design. A second-order response surface model was developed to predict the yield of castor oil ethyl ester as a function of transesterification process parameters. The developed models indicated that the predicted values are well in agreement with the experimental results. Finally, optimization of transesterification process parameters was carried out using a response surface methodology-based genetic algorithm. The optimization results indicated a reaction temperature of 41°C, catalyst concentration of 1.25% w/w of oil, and ethanol to oil molar ratio of 18.42 for achieving a higher yield of castor oil ethyl ester of 93.9%.     

氨基磺酸非均相催化菜籽油及废油脂制备生物柴油

采用正交试验和单因素试验的方法研究了氨基磺酸催化菜籽油及废油脂与甲醇的酯交换过程,考察了醇油物质的量比、催化剂用量、反应温度和反应时间对反应收率的影响。结果表明:菜籽油酯交换的最佳反应条件为醇油物质的量比6∶1,氨基磺酸用量为原料油质量的1.0%,反应温度60℃,反应时间20 min,此工艺条件下,脂肪酸甲酯的收率达到95.6%;废油脂酯交换的最佳反应条件为醇油物质的量比8∶1,氨基磺酸用量为原料油质量的1.0%、反应温度65℃,反应时间30 min,此工艺条件下,脂肪酸甲酯的收率达到87.5%。利用红外光谱表征了菜籽油和生物柴油的结构,气相色谱分析了生物柴油的组成。     

Macroalgae: Raw material for biodiesel production

The objective of this paper is to study marine macroalgae as an alternative raw material for the biodiesel production. The obtained results show that biodiesel production from oil extracted from marine algae is feasible by transesterification. Oil extraction can be carried out simultaneously with the transesterification. To investigate the optimum reaction conditions, the reaction was carried out at various methanol to oil molar ratios, catalyst concentrations and reaction temperatures. The process yields 1.6–11.5% depending on the reaction conditions. Moreover, the properties of macroalgae transesterification residue after transesterification were analyzed, concluding that it is a suitable material for fuel pellets manufacturing.     

Analysis and evaluation of operating variables for the yield of Karanja and neem oil-based biodiesel production

The aim of this research is to present the possibilities of the use of non-edible oils in biodiesel production, to consider the various methods for treatment of non-edible oils and to emphasise the influence of the operating and reaction conditions on the process rate and the ester yield. Because of biodegradability and non-toxicity biodiesel has become more attractive as alternative fuel. Biodiesel is produced mainly from vegetable oils by transesterification. For economic and social reasons, edible oils should be replaced by lower-cost and reliable feedstock for biodiesel production, such as non-edible plant oils. In this work biodiesel is produced from neem and Karanja by using butanol, propanol, ethanol and methanol as alcohols and KOH and NaOH as alkali catalysts by the transesterification process. The aim of this research is to analyse the different reaction parameters such as catalyst concentration, type of catalyst, types of alcohol, alcohol to oil molar ratio, reaction time and reaction temperature on the yield of biodiesel from non-edible oils. The maximum yield obtained was 95% with Karanja as oil with methanol and KOH as alkali catalyst at oil to alcohol molar ratio of 6:1 in 1 h at 60°C. Special attention is paid to the possibilities of producing biodiesel from non-edible oils.     

Production of biodiesel fuels from linseed oil using methanol and ethanol in non-catalytic SCF conditions

Methyl and ethyl esters as biodiesel fuels were prepared from linseed oil with transesterification reaction in non-catalytic supercritical fluids conditions. Biodiesel fuel is a renewable substitute fuel for petroleum diesel fuel made from vegetable or animal fats. Biodiesel fuel has better properties than that of petroleum diesel fuel such as renewable, biodegradable, non-toxic, and essentially free of sulfur and aromatics. The purpose of the transesterification process is to lower the viscosity of the oil. The viscosity values of linseed oil methyl and ethyl esters highly decreases after transesterification process. The viscosity values of vegetable oils vary between 27.2 and 53.6 mm² s^?1, whereas those of vegetable oil methyl esters between 3.59 and 4.63 mm² s^?1. Compared with no. 2 diesel fuel, all of the vegetable oil methyl esters were slightly viscous. The flash point values of vegetable oil methyl esters are highly lower than those of vegetable oils. The transesterification of linseed oil in supercritical fluids such as methanol and ethanol has proved to be the most promising process. Methanol is the commonly used alcohol in this process, due in part to its low cost. Methyl esters of vegetable oils have several outstanding advantages among other new-renewable and clean engine fuel alternatives. The most important variables affecting the methyl ester yield during the transesterification reaction are molar ratio of alcohol to vegetable oil and reaction temperature. Biodiesel has become more attractive recently because of its environmental benefits. Biodiesel is an environmentally friendly fuel that can be used in any diesel engine without modification.     

Biofuel and biomass from marine macroalgae waste

Nowadays, biofuel production of new raw materials has gained renewed interest. For that reason, the objective of this work is to use marine macroalgae for biodiesel and biomass production. The obtained results show that macroalgae are a suitable energy source for biodiesel production by direct transesterification, avoiding the previous step of oil extraction. It is an effective process because 95% of the oil is extracted. To analyze the optimum reaction conditions, the reaction was carried out at different amounts of methanol, catalyst concentrations, reaction temperatures, and reaction times. In addition, the macroalgae residue after transesterification was analyzed and it is suitable as fuel in biomass boilers.     

双低菜籽油制备生物柴油的工艺探索

实验研究双低菜籽油在催化剂NaOH的作用下与乙醇发生转脂化反应生成菜籽油乙脂(生物柴油)。实验结果表明:该转脂化反应的最佳操作条件为:NaOH用量为菜籽油量的0.8%;油醇摩尔比为1:4.5;搅拌时间为2h;反应温度为20～30℃;水的含量必须控制在油重的0.1%以下。     

Eco-friendly biodiesel production from olive oil waste using solar energy

This study was carried out to produce biodiesel from olive oil waste by transesterification reaction. Several important reaction variables (the weight ratio of oil to methanol, the temperature, and reaction time) were evaluated to obtain a high quality of biodiesel fuel that meets authentic standards. Solar energy was applied for the transesterification reaction and electricity generated by photovoltaic panels was used to power a motor for mixing the reaction solution.     

Utilization of BA (boiler ash) as catalyst for transesterification of palm olein

BA (boiler ash) (empty fruit bunch ash) was used as a source of pseudo-homogeneous base catalyst for transesterification of palm olein. BA successfully transesterified palm olein at mild reaction conditions (3 wt.% dried BA, 15:1 methanol:oil molar ratio, reaction temperature of 60 °C and reaction time of 30 min) to produce 90% methyl esters. Although BA works very well as a catalyst for transesterification, it is not reusable as the active species in the catalyst tend to leach out of the system during reaction. BA was prepared for transesterification by drying in oven at 105 ± 2 °C to constant weight.