共查询到19条相似文献,搜索用时 187 毫秒
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《现代化工》2018,(12)
以餐饮废油为碳源,浓硫酸为磺化剂,在管式电阻炉中一步炭化和磺化制备得到一种新的炭基固体酸催化剂,并对制备的固体酸催化剂进行理化性能表征。将制备的固体酸催化剂用于催化油酸与甲醇酯化反应合成生物柴油。考查了废油炭化温度对固体催化剂活性的影响。结果表明,在餐饮废油/浓硫酸质量比为0.25、温度为220℃、N_2流量为80 cm~3/min、时间30 min时,制备的固体酸催化剂活性最高。此外,考查了酯化反应条件对油酸转化率的影响,结果表明,当反应时间为10 h、反应温度为80℃、甲醇油酸摩尔比为10∶1、催化剂质量为油酸质量的10.0%时,油酸最大转化率为95.8%。当催化剂循环利用第3次时,油酸转化率仍达到69.1%。 相似文献
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《精细化工》2017,(1)
用高温磺化法制得复合型稀土改性固体酸催化剂SO_4~(2-)/C-TiO_2-CeO_2,以油酸和甲醇的酯化反应为探针反应,考察了稀土氧化物CeO_2的质量分数、磺化温度、磺化时间对催化剂SO_4~(2-)/C-TiO2-CeO2催化活性的影响。催化剂SO_4~(2-)/C-TiO_2-CeO_2的最佳制备条件为:CeO_2的质量分数为2%(以活性炭质量计)、磺化温度为200℃、磺化时间为10h。该条件下制备的催化剂用于催化油酸与甲醇的酯化反应,酯化率可达到94.78%。利用FTIR、XRD、SEM、DTG、XRF对固体酸催化剂进行了表征,结果表明:稀土氧化物CeO_2和金属氧化物TiO_2共同作用可固化SO_4~(2-),并与SO_4~(2-)形成配位结构,增强了固体酸催化剂的催化性能并提高了其热稳定性。 相似文献
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采用高温磺化法制备复合型稀土改性固体酸SO42-/C-TiO2-CeO2,以油酸与甲醇发生的酯化反应作为探针反应,考察稀土氧化物CeO2的百分含量、磺化温度、磺化时间对催化剂SO42-/C-TiO2-CeO2催化活性的影响。结果表明,制备催化剂SO42-/C-TiO2-CeO2的最佳条件:稀土CeO2的含量为2%、磺化温度为200℃、磺化时间为10h,此条件下催化油酸与甲醇发生酯化反应的酯化率最高,可达到94.78%。利用红外光谱、X射线衍射、扫描电镜、热重分析、X荧光等手段对固体酸催化剂进行表征分析,表明稀土氧化物CeO2和金属氧化物TiO2共同作用下可固化SO42-,并与SO42-形成配位结构,增强固体酸催化剂的催化性能并提高稳定性。 相似文献
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María Dolores López‐Ramírez Ulises Miguel García‐Ventura Fabricio Omar Barroso‐Muñoz Juan Gabriel Segovia‐Hernández Salvador Hernández 《化学工程与技术》2016,39(2):271-275
The esterification of oleic acid and methanol using sulfuric acid as a homogeneous catalyst is studied in reactive‐separation systems. The conversion of the free fatty acid was investigated in two different experiments with the molar ratio of methanol/oleic acid, amount of catalyst, temperature, and reaction time as variables. The conversion of the free fatty acid was found to depend strongly on the molar ratio of methanol/oleic acid. The reaction time had a direct effect on the conversion of the free fatty acid, and this conversion decreased with higher temperature. These results were valuable for a preliminary study on biodiesel production, using an acid homogeneous catalyst in a reactive dividing‐wall distillation column. 相似文献
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通过溶胶-凝胶法和浸渍法制备了二氧化硅负载的硫酸铝催化剂,并测试其在油酸与甲醇酯化反应中的活性,进行高酸值生物柴油原料酯化降酸的研究,考察了催化剂的焙烧温度、硫酸铝的负载量、醇酸比、催化剂用量、反应温度、反应时间及重复利用性等因素对油酸转化率的影响。结果表明,二氧化硅负载的硫酸铝催化剂在油酸和甲醇的酯化反应中具有良好的催化性能。在n(甲醇)∶n(油酸)=8,m(20-Al2(SO4)3/SiO2(500))∶m(油酸)=0.075,反应温度65℃和反应时间为180 min的条件下,油酸的转化率达到92.9%。油酸和甲醇在Al2(SO4)3/SiO2固体酸催化剂的酯化反应符合准一级反应动力学方程,表观活化能为41.56 kJ/mol,指前因子为3.52×104min-1。 相似文献
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A novel phosphorylated ordered mesoporous carbon (POMC) solid acid catalyst has been prepared by modifying mesoporous carbon with phosphoric acid, and was employed to catalyze the esterification oleic acid with methanol. The effects of the carbonization temperature on the type of phosphorus species formed, the phosphorus content and the amount of acid in the POMC were investigated. A mechanism for the phosphorylation of the ordered mesoporous carbon is proposed. The POMCs have good catalytic activity for the esterification of oleic acid and showed good reusability. 相似文献
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Biodegradable trimethylolpropane triesters of oleic acid were synthesized by esterification of trimethylolpropane and oleic acid over a multi-SO3H-functionalized strong Brønsted acidic ionic liquid as the catalyst. The results showed that the esterification can proceed satisfactorily over the catalyst at an ambient pressure even without simultaneous removal of water. Under the optimal reaction conditions (temperature: 100 °C, reaction time: 3 h, reactant molar ratio: 3.6:1, and catalyst amount, high conversion rate of trimethylolpropane (99.0%) and selectivity of trimethylolpropane triester (92.1%) were obtained. The ionic liquid was reused six times after the removal of water and no obvious change in catalytic activity was detected. Operational simplicity, high yields along with good reusability makes the multi-SO3H-functionalized ionic liquid a promising catalyst for the esterification of trimethylolpropane with oleic acid. 相似文献