复合固体酸催化餐饮废油合成生物柴油的研究

通过酯转换反应生成脂肪酸甲酯即生物柴油的研究,考察了催化剂混合摩尔比、催化剂用量、醇油摩尔比、反应温度、反应时间等因素对生物柴油产率的影响;采用甘油铜比色法测定甘油含量来反映生物柴油的产率;采用红外光谱测试技术对酯交换产物进行分析.     

花生油转酯化制备生物柴油工艺条件的研究

研究了花生油在KOH催化作用下通过酯交换反应制备生物柴油的过程.考察了醇油摩尔比、催化剂用量、反应温度、反应时间等操作条件对反应的影响.结果表明最佳酯交换反应条件为醇油摩尔比61、KOH用量1%(质量分数)、反应温度60℃、反应时间20min.同时,通过气相色谱-质谱对生物柴油进行了结构分析,生物柴油主要由C160、C180、C181和C182的脂肪酸甲酯组成,其中亚油酸甲酯含量最高,相对质量分数高达51.485%.     

固体碱催化脂肪酸甲酯甘油解制备单甘酯

以自制La2O3/Mg O固体碱为催化剂,采用脂肪酸甲酯甘油解合成单甘酯;采用薄层色谱、柱色谱、FTIR、1HNMR对产品进行了分离和鉴定;考察了反应温度、甘油与脂肪酸甲酯投料比、反应时间以及催化剂用量对单甘酯产率的影响。结果表明,合成产物单甘酯的红外光谱图与其标准品红外谱图相符;1HNMR数据表明,产品单甘酯为亚油酸单甘酯和棕榈酸单甘酯的混合物;合成单甘酯的最适宜条件为:反应温度240℃,催化剂添加量0.75%(以脂肪酸甲酯质量计),投料比n(甘油)∶n(脂肪酸甲酯)=2∶1,反应时间2.5 h;在该条件下单甘酯产率达70.53%。     

海滨锦葵油超临界法制备生物柴油工艺优化

以海滨锦葵油为原料,利用超临界法制备脂肪酸甲酯(生物柴油). 通过单因素实验及正交实验研究了醇/油摩尔比、反应压力、搅拌强度、反应时间、反应温度、水分和酸值等因素对酯交换率的影响. 结果表明,在实验范围内各影响因素对酯交换率的影响依次为：反应温度>反应压力>反应时间>搅拌强度>醇/油摩尔比. 海滨锦葵油超临界法制备生物柴油的最佳工艺条件为：反应温度300℃,反应压力12 MPa,反应时间9 min,搅拌强度300 r/min,醇/油摩尔比30. 在此条件下,酯交换反应3次,酯交换率可达97.62%.     

离子液体催化蓖麻油酯交换制备生物柴油

制备了对水稳定性好的[Bpy] HSO4离子液体,对其催化蓖麻油酯交换反应制备生物柴油进行了研究.在常压回流温度下,考察了醇油摩尔比、催化剂用量(催化荆质量/油质量)及反应时间对酯交换反应的影响.在反应温度为常压回流温度、醇油摩尔比为9∶1、催化剂用量为8%、反应时间为8 h的优化工艺条件下,甘油收率半均可达93%.产物中甲酯质量分数高达96.7%.催化剂可重复使用多次.     

固体酸催化制备环氧脂肪酸甲酯

氨基磺酸催化下,环氧脂肪酸甘油酯与甲醇进行酯交换反应制备环氧脂肪酸甲酯。考察了醇油摩尔比、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,醇油摩尔比为8∶1,催化剂用量为原料油总质量的2.5%,反应温度70℃,反应时间为2.0h,反应收率高达85.6%。采用气相色谱分析了产物的纯度,红外光谱表征了产物分子的官能团结构。     

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%。     

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％。     

碱催化法制备生物柴油工艺研究

在250m l间歇式高压反应器中,以大豆油为原料,研究KOH催化甲醇酯交换反应制备生物柴油的工艺条件。主要考察了醇油摩尔比、反应温度、反应时间、催化剂用量等操作条件对脂肪酸甲酯转化率的影响。结果表明,当KOH用量为1%(wt),醇油摩尔比为5∶1,反应温度为65℃时,反应时间为15m in,脂肪酸甲酯的转化率可以达到92%。     

碱性离子液体在制备生物柴油中的应用

文章研究了碱性离子液体1-丁基-3-甲基咪唑氢氧盐（[Bmim]OH）催化蓖麻油酯交换制备生物柴油的工艺。考察了醇油比、催化剂用量、反应温度、反应时间等因素对脂肪酸甲酯的得率的影响。研究表明以[Bmim]OH为催化剂,脂肪酸甲酯得率达到82.3%。最佳反应条件为：醇油摩尔比9∶1,催化剂用量8%,反应温度50℃,反应时间90 min。     

Synthesis and component confirmation of biodiesel from palm oil and dimethyl carbonate catalyzed by immobilized-lipase in solvent-free system

The transesterification of palm oil and dimethyl carbonate (DMC) for preparing biodiesel has been carried out at the catalysis of immobilized-lipase in solvent-free system. The components were all confirmed by GC and GC–MS analysis. The fatty acid methyl esters (FAMEs) were analyzed with internal standard method. The fatty acids glycerol carbonate esters (FAGCs) were characterized as the intermediates. And, glycerol dicarbonate (GDC) was confirmed as the byproduct by comparing with the model compound. Moreover, the effects of the reaction conditions (type of lipases, molar ratio of DMC and palm oil, amount of catalyst, reaction temperature and time) on the yield of FAMEs were investigated. The yield of FAMEs could reach 90.5% at 55 °C for 24 h with the molar ratio of DMC to oil 10:1 and the catalyst amount of 20% Novozym 435 (based on the oil weight). There was no obvious loss in the FAMEs yield after Novozym 435 having been used for eight cycles.     

碳酸二丙酯的绿色合成及其与DMC相平衡数据测定

用碳酸二甲酯(DMC)与正丙醇(n-PrOH)酯交换反应合成了碳酸二丙酯(DPC),考察了催化剂种类、物料摩尔比、催化剂用量、温度和时间等因素对反应的影响。结果表明,碳酸钾(K2CO3)具有较好的催化活性和选择性,反应最佳工艺条件为:常压,反应温度95℃,n(n-PrOH)∶n(DMC)=3∶1,w(K2CO3)=1%,反应时间5 h,DMC转化率95.9%,DPC产率73.7%。优化条件下的重复实验表明,该反应易于控制,重复性好。测定了常压下DPC和DMC的气液相平衡数据,结果表明,在常压下DPC和DMC二元物系不形成共沸物。     

乙醇与餐饮废油制备生物柴油的工艺研究

以餐饮废油和乙醇为原料,以氢氧化钾为催化剂,采用酯交换法制备生物柴油。考查了醇油摩尔比、催化剂用量、反应时间和温度对原料转化率的影响。正交试验结果表明,餐饮废油与乙醇酯交换反应的最佳反应条件为：醇油摩尔比12∶1,催化剂用量1.25%,反应温度78℃,反应时间1.5h。在此反应条件下,餐饮废油转化率达65.12%;在此基础上引入四氢呋喃作助溶剂,转化率可提高至86%~90%。     

Transesterification kinetics of palm olein oil using supercritical methanol

Continuous transesterification of palm olein oil using supercritical methanol was investigated in the absence of a catalyst. The variables studied were reaction temperature (270–350 °C), pressure (20–40 MPa), and residence time (5–25 min), with a methanol-to-oil molar ratio of 40. Preheating at 245 °C was used to form a homogeneous phase in the absence of thermal decomposition of palm olein oil. The activation energies and reaction activation volumes of the fatty acid methyl ester (FAME), and those of the individual components (C16:0, C18:0, C18:1, and C18:2 methyl esters), were calculated. The entropies of activation (ΔS^‡) of the transesterification reactions were also obtained. As the transesterification of vegetable oil in supercritical methanol included a strongly negative (−175 J/mol K) entropy of activation, transesterification required harsh conditions.     

Production of biodiesel from waste vegetable oil using impregnated diatomite as heterogeneous catalyst

In this study, biodiesel was produced from waste vegetable oil using a heterogeneous base catalyst synthesized by impregnating potassium hydroxide (KOH) onto diatomite. Response surface methodology based on a central composite design was used to optimize four transesterification variables:temperature (30–120 °C), reaction time (2–6 h), methanol to oil mass ratio (10%–50%) and catalyst to oil mass ratio (2.1%–7.9%). A quadratic poly-nomial equation was obtained to correlate biodiesel yield to the transesterification variables. The diatomite–KOH catalyst was characterized using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) and a scanning electron microscope (SEM) equipped with an energy dispersive X-ray detector (EDS). A maximum biodiesel yield of 90%(by mass) was obtained. The reaction conditions were as follows:methanol to oil mass ratio 30%, catalyst to oil mass ratio 5%, reaction time 4 h, and reaction temperature 75 °C. The XRD, FTIR and SEM (EDS) results confirm that the addition of KOH modifies the structure of diatomite. During impregnation and calcination of the diatomite catalyst the K2O phase forms in the diatomite structural matrix and the active basicity of this compound facilitates the transesterification process. It is possible to recycle the diatomite–KOH catalyst up to three times. The crucial biodiesel properties from waste vegetable oil are within the American Stan-dard Test Method specifications.     

In-situ synthesis of MCM-41 on ceramic membranes and its application in transesterification as catalyst support for p-toluenesulfonic acid

In this study, a new kind of solid acid catalyst p-toluenesulfonic acid/MCM-41/ceramic membrane was synthesized by in situ synthesis and impregnation method, which has shown its favorable catalytic activity, as verified in the transesterification and catalyst characterization. The catalyst was characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. The transesterification of palm oil and methanol results showed that p-toluenesulfonic acid/MCM-41/ceramic membrane had the highest catalytic activity with immersing p-toluenesulfonic acid solution concentration of 0.15 mol/L. Different operation parameters of the transesterification of palm oil with methanol, such as catalyst amount, catalytic mass ratio, reaction time, reaction temperature and methanol/palm oil molar ratio were investigated. Under the optimum conditions of 4 % of fresh catalyst (catalytic mass ratio is 4.37 %), 80 min of reaction time, reaction temperature of 120 °C and methanol to palm oil molar ratio of 12:1, a relatively high fatty acid methyl ester yield of 95.6 % was obtained.     

KOH/ZrO2催化制备生物柴油新工艺

采用浸渍法,将KOH负载在新型载体氧化锆上,通过高温煅烧得到了固体碱催化剂。探讨了制备条件对催化剂催化酯交换反应活性的影响,获得了催化剂的最佳制备条件,以大豆油和甲醇为原料研究并优化了催化酯交换反应制备生物柴油的工艺条件。结果表明,固体碱催化剂KOH/ZrO₂的最佳制备条件为：KOH负载量20%,煅烧温度600℃,煅烧时间2 h。固体碱催化剂催化酯交换反应的最优反应条件为：醇油比9：1,反应温度75℃,反应时间3 h,催化剂用量4.0%。各因素对产率影响的大小为：醇油摩尔比 > 反应温度 > 反应时间 > 催化剂用量。     

Na/SiO2新型固体碱催化制备生物柴油的研究

以NaOH、正硅酸乙酯和乙醇为原料,经溶胶-凝胶法制备新型固体碱催化剂（Na/SiO₂）,用于催化大豆油与甲醇的酯交换反应制备生物柴油,研究催化剂焙烧温度、n(NaOH)∶n(SiO₂)、n(甲醇)∶n(大豆油)、催化剂用量和反应时间对产率的影响以及催化剂的稳定性。结果表明,固体碱催化剂Na/SiO₂在大豆油与甲醇的酯交换反应中具有较高的催化活性,在催化剂焙烧温度600 ℃、n(NaOH)∶n(SiO₂)=2∶1、n(甲醇)∶n(大豆油)=15∶1、催化剂用量为大豆油质量的7%和反应时间3 h的条件下,脂肪酸甲酯产率可达97.42%,催化剂在稳定性试验中呈现出优良的稳定性。     

Na_2CO_3/MCM-41型固体碱催化制备生物柴油

以MCM-41为载体负载Na2CO3制备Na2CO3/MCM-41型酯交换催化剂,用于催化大豆油制备生物柴油。并研究了催化剂用量、反应物的摩尔比、反应温度和反应时间等因素对该反应的影响。结果表明,最佳反应条件是n(甲醇)∶n(大豆油)=16∶1,催化剂用量为大豆油质量的3%,反应温度为60℃,反应时间为3 h条件下,酯交换转化率可达35%以上。     

用于生物柴油制备的KF/Al2O3固体碱催化剂的研究

采用浸渍法制备了KF/Al₂O₃固体碱催化剂，并将其应用于大豆油与甲醇酯交换制备生物柴油的反应。通过酯交换反应的转化率对催化剂制备工艺进行了优化，得出最佳制备条件：KF理论负载质量分数为Al₂O₃的45%，浸渍时间6 h，焙烧温度500 ℃，优化条件下制备的催化剂在大豆油与甲醇物质的量比为12∶1、催化剂用量为油质量的2%、反应时间3 h和反应温度(60～65) ℃条件下,酯交换转化率可达97.15%。