双液相萃取棉籽油制备脂肪酸甲酯

以双液相萃取技术处理棉籽，在得到脱毒棉粕的同时得到含有高质量毛油的非极性相。以非极性相作为与甲醇进行酯交换反应的原料，得到脂肪酸甲酯和甘油。考察了非极性相溶剂石油醚与棉籽油的比例对酯交换转化率和洗涤粗产品用水量的影响，确定了石油醚与棉籽油的最佳质量比为3，在此条件下，洗涤用水量可降低一半。考察了醇油比、催化剂用量、反应温度、反应时间等参数对转化率的影响。应用正交实验的方法找出酯交换反应的适宜条件为：醇油比6：1，催化剂用量1.1％，反应温度60℃，反应时间120min。在此反应条件下，产物中脂肪酸甲酯的含量可达97.4％。     

棉籽油制备生物柴油的研究

采用棉籽油为原料,在催化剂(KOH)的作用下,通过甲醇酯交换反应制备生物柴油;考察了醇油比、催化剂用量、反应温度、反应时间对生物柴油收率的影响;确定了棉籽油酯交换反应的适宜反应条件:醇油物质的量比6:1,催化剂用量1.2%,反应温度60℃,反应时间30 min,在此条件下,柴油收率为96.3%,其质量指标密度、牯度、甲酯和硫含量等符合国外标准.     

棉籽油制备生物柴油的工艺条件研究

介绍了以甲醇钠为催化剂,使用棉籽油与甲醇进行酯交换反应制备生物柴油的工艺过程.采用正交实验的方法研究得到酯交换反应的最佳工艺条件为:醇油摩尔比6:1,催化剂甲醇钠的质量分数为0.6%.反应温度50℃,反应时间60 min,收率达到96%.该工艺设备简单,工艺成熟,适于多种油品的中小规模生产.     

棉籽油酯交换制备生物柴油固体碱催化过程研究

生物柴油(脂肪酸甲酯)可以由棉籽油与甲醇在碱催化剂的作用下通过酯交换反应制得.本实验通过高温煅烧氢氧化镁、碳酸钙及镁-铝水滑石得到了相应的固体碱催化剂MgO、CaO及MgO-Al2O3,并对催化剂活性进行评价.实验结果表明,CaO及MgO-Al2O3具有较高的酯交换反应活性:在230℃,醇油摩尔比12:1及催化剂用量为棉籽油2%(wt)的条件下,反应3 h后,甲酯的收率达到90%以上.CO2-TPD实验结果表明,CaO 及MgO-Al2O3具有较强和较多的碱性位,而催化剂的活性与碱强度及碱性位数量直接相关.     

混合离子液体催化反应精馏合成乙酸正己酯

离子液体催化反应精馏是提高酯交换平衡反应转化率的一种绿色有效方法。以离子液体1-丙基磺酸-3-甲基咪唑三氟甲烷磺酸盐（［PSO₃HMIm］［OTf］）和离子液体1-辛基-2,3-二甲基咪唑双（三氟甲烷磺酰）亚胺盐（［OMMIm］［Tf₂N］）的混合物作为乙酸甲酯和正己醇进行酯交换反应合成乙酸正己酯的催化剂,测定了酯交换反应动力学。探讨了混合比、反应温度、反应物初始摩尔比、催化剂浓度对反应速率和乙酸甲酯转化率的影响,考察了催化剂的回收性能。利用实验数据回归得出混合离子液体催化酯交换反应动力学方程。在反应动力学的基础上进行了乙酸甲酯和正己醇的酯交换反应精馏流程模拟,分析了理论板数、回流比、进料位置及反应段塔板数、催化剂用量、持液量等参数对反应精馏塔的影响。在优化的操作条件下,获得纯度为0.9993的乙酸正己酯产品。     

大豆油异丙酯的合成研究

用碱催化酯交换法合成大豆油异丙酯,考察了醇油摩尔比、催化剂用量、反应温度、反应时间对酯交换反应的影响。结果表明,合成大豆油异丙酯的最佳条件如下:醇油摩尔比10∶1,反应时间60 min,反应温度80℃,碱催化剂浓度2.0%。在此条件下,大豆油异丙酯的产率达53.07%。最后对比研究了大豆油甲酯、乙酯、异丙酯的合成,得出不同结构的醇与大豆油进行酯交换反应的规律。色谱表征表明,经酯交换作用,原料油成功转化为生物柴油。     

酯交换法制备乙酸正丁酯动力学研究

为了给乙酸正丁酯的工业生产提供动力学支持,文章在间歇搅拌釜式反应器中利用酯交换法将乙酸甲酯转化为乙酸正丁酯。首先筛选出Si-3为最优催化剂,然后考察了转速、反应温度、催化剂用量、醇酯比等因素对反应过程的影响,确定较优的实验条件为转速400 r/min,反应温度70℃,催化剂用量(质量分数)20%,醇酯比(摩尔比)为1.25∶1。在323—343 K下,将实验数据拟合后得到酯交换反应的动力学方程。正反应速率常数为6 291.15 L/(mol·s),正反应活化能50 134.7 J/mol;逆反应速率常数为137.72 L/(mol·s),逆反应活化能38 324 J/mol。通过实验与计算值的比较验证,此宏观动力学方程合理,可用于模拟计算。     

固体酸催化棉籽油酯交换制备生物柴油

生物柴油(脂肪酸甲酯)可以由棉籽油与甲醇在酸催化剂的作用下通过酯交换反应制得. 通过硫酸改性氧化钛、氧化锆，并经过高温煅烧得到了相应的固体强酸催化剂TiO2-SO42-, ZrO2-SO42-，并对催化剂活性进行了评价. 实验结果表明，TiO2-SO42-和ZrO2-SO42-与改性前的氧化物相比具有较高的酯交换反应活性. 在230℃、醇油摩尔比12:1及催化剂用量为棉籽油2%(w)的条件下，反应8 h后甲酯的收率达到90%以上. 与固体碱催化剂相比，固体酸催化剂对原料的酸度有更强的适应性. 红外吡啶吸附光谱表明，TiO2-SO42-与ZrO2-SO42-具有较强的L酸和B酸中心.     

L-抗坏血酸硬脂酸酯的合成条件探索

文章对L-抗坏血酸硬脂酸酯的最佳合成条件进行探索。通过各种不同的实验条件得出最佳合成条件为：抗坏血酸比硬脂酸甲醣为1：1．3（摩尔比）,催化剂浓硫酸比（抗坏血酸＋硬脂酸甲酪）为1：0．10（摩尔比）,反应温度24℃,反应时闯24h。在此条件下可获得总产率为77％的抗坏血酸硬脂酸酯。考察了以硬脂酸甲酯和L-抗坏血酸为原料,通过酯交换法合成L-抗坏血酸硬脂酸酯的最佳合成条件。文章对L-抗坏血酸硬脂酸酯的最佳合成条件进行探索。通过各种不同的实验条件得出最佳合成条件为：抗坏血酸比硬脂酸甲酯为1：1.3（摩尔比）,催化剂浓硫酸比（抗坏血酸＋硬脂酸甲酯）为1：0．10（摩尔比）,反应温度24℃,反应时间24h。在此条件下可获得总产率为77％的抗坏血酸硬脂酸酯。考察了以硬脂酸甲酯和L-抗坏血酸为原料,通过酯交换法合成L-抗坏血酸硬脂酸酯的最佳合成条件。     

采用抽油烟机废油合成增塑剂的实验研究

以抽油烟机废油脂和正丁醇为原料,甲醇钠为催化剂,通过酯交换反应制取非芳基绿色增塑剂——脂肪酸丁酯。研究了醇酸摩尔配比、催化剂用量、反应时间和反应温度对酯交换反应产物收率的影响。结果表明,该反应的最佳工艺条件为:醇油摩尔比为4∶1,催化剂用量为0.5%,反应时间为4 h,反应温度110℃。在最佳工艺条件下,酯交换反应产物丁酯增塑剂收率达到了83.05%以上。利用气相色谱对产物含量进行了分析,用红外光谱表征了产物的结构。     

Biodiesel production using tetramethyl- and benzyltrimethyl ammonium hydroxides as strong base catalysts

In recent years, the acceptance of fatty acid methyl esters (biodiesel) as an alternative fuel has rapidly grown in EU. The most common method for biodiesel production is based on triglyceride transesterification to methyl esters with dissolved sodium hydroxide in methanol as catalyst. In this study, cottonseed oil and used frying oil were subjected to the transesterification reaction with tetramethyl ammonium hydroxide and benzyltrimethyl ammonium hydroxide as strong base catalysts. This work investigates the optimum conditions for biodiesel production using amine-based liquid catalysts. Biodiesel ester content was strongly related with the type of feedstock and the reaction variables, such as those of the catalyst concentration, methanol to oil molar ratio, and reaction time. The overall results suggested that the transesterification of cottonseed oil achieved high conversion rates with both catalysts, while the use of waste oil resulted in lower yields of methyl esters due to the possible formation of amides.     

Ethanolysis of castor and cottonseed oil: A systematic study using classical catalysts

Several classical catalytic systems for the transesterification reaction have been used to produce FA ethyl esters (FAEE) from castor and cottonseed oils The effects of the amount and nature of the catalyst, and of the reaction temperature, on the yields of FAEE were determined. The most efficient transesterification of castor oil was achieved in the presence of methoxide and acid catalysts, whereas for cottonseed oil, which has a composition that is much more similar to most vegetable oils than is castor oil, the highest yields of FAEE were obtained following base-catalysed ethanolysis.     

棉籽油酯交换法合成生物柴油的工艺研究

介绍了利用复合碱性催化棉籽油酯交换合成生物柴油的工艺过程,正交实验得出的适宜工艺条件为:醇油摩尔比为5.5∶1,反应时间50 min,反应温度35℃,催化剂用量1.0%,产率可达96%。并比较了生物柴油与0#柴油的性能。     

微波强化棉籽油制备生物柴油的研究

利用微波强化以棉籽油和甲醇为原料,KOH为催化剂制备生物柴油。考察醇油摩尔比、催化剂用量、反应时间和微波功率对酯交换反应的影响。结果表明,醇油摩尔比为9∶1,催化剂用量为1.0%,反应时间为3 min,微波功率360 W为最优反应条件。在此反应条件下生物柴油产率可达94%。与传统合成方法相比,该方法可缩短反应时间30~35 min。所得生物柴油主要质量指标达到我国和欧洲(EN14214)生物柴油质量标准,通过红外光谱分析表明,棉籽油生物柴油具有生物柴油所含的官能团。     

固体酸催化废油酯制备脂肪酸丁酯

研究以废油酯为原料在固体酸催化作用下与丁醇酯交换反应制备脂肪酸丁酯的过程,采用气相色谱对脂肪酸丁酯的含量进行分析。考察了醇油摩尔比、催化剂用量、反应温度和反应时间对酯化反应转化率的影响。结果表明,该反应的最适宜工艺条件为：醇油摩尔比16∶1,催化剂用量1.2%,反应温度115℃,反应时间4 h。废油酯在最优工艺条件下,经过酯交换反应得到的转化率超过83%。     

RETRACTED ARTICLE: Optimization of Biodiesel Production Using a Magnetically Stabilized Fluidized Bed Reactor

A biodiesel production process using magnetically stabilized fluidized bed reactor (MSFBR) has been developed based on the refined cottonseed oil. The reactant flow rate and magnetic field intensity effects on the nanometer magnetic catalyst behavior in the column were investigated. Orthogonal experiments (L₄(2)³) were applied to optimize the best transesterification reaction conditions. Reaction temperature, methanol to oil molar ratio, and reactant flow rate were the main factors to influence transesterification conversion efficiency. These three factors chosen for the present investigation were based on the results of single-factor tests. The optimum transesterification reaction conditions of cottonseed oil were determined in MSFBR as follows: methanol to oil molar ratio 8:1, 40 cm³ min⁻¹ reactant flow rate, 225 Oe magnetic field intensity and reaction temperature of 65 °C, the conversion efficiency reached 97% in 100 min. The cold filter plugging point and kinematic viscosity of cottonseed oil biodiesel were higher than that described by Chinese specifications of biodiesel because of the special fatty acid profiles of cottonseed oil. The activity stability of the nanometer magnetic solid catalyst in MSFBR was much better than that in the autoclave stirred reactor (ASR).     

棉籽油二乙二醇甲醚酯新型生物柴油制备

以精制棉籽油、无水甲醇和二乙二醇单甲醚为原料,KOH为催化剂,通过酯交换反应制备出一种高含氧量的新型生物柴油;采用正交试验研究了醇油比、催化剂用量、温度和反应时间对产率的影响,得出了最佳合成条件;运用红外光谱法、核磁共振法、凝胶渗透色谱法进行了产物结构表征;此外柴油机台架试验也表明燃烧该新型生物柴油可有效减少柴油机的废气排放。     

Ultrasonic Pretreatment Transesterification for Solid Basic-Catalyzed Synthesis of Fatty Acid Methyl Esters

Generally, ultrasound irradiation is required throughout the reaction for fatty acid methyl esters (FAME, namely, biodiesel) production, which is energy-consuming and difficult to scale-up. In order to improve the industrial application of ultrasonic technology, a systematic study of ultrasonic pretreatment solid basic (Na₂SiO₃)-catalyzed transesterification for FAME production from cottonseed oil was carried out, and the effect of ultrasonic waves on the properties of Na₂SiO₃ catalyst was assessed by X-ray diffraction (XRD), Fourier transform Infrared (FTIR) and scanning electron microscopy (SEM) characterization of fresh and collected catalysts. An ultrasonic frequency of 30 kHz, ultrasonic power of 200 W and ultrasonic pretreatment irradiation time of 30 min was determined to guarantee a satisfactory degree of transesterification. The optimum production was achieved in the reaction system at 45 °C with methanol/cottonseed oil molar ratio 5:1, catalyst dosage 3% and stirring speed 350 rpm resulting in a FAME yield of above 97% after 60 min of reaction under mechanical stirring with the ultrasonic pretreatment process. The new process has a shorter reaction time, a more moderate reaction temperature, a less amount of methanol and catalyst than only the mechanical stirring process without essential damage to activity and the structure of catalyst. These results are of great significance for applying the ultrasonic pretreatment method to produce FAME.