SO_(4)^(2-)/ZrO_(2)-杭锦2^(#)土催化制取生物柴油工艺的优化

Optimization production technology of biodiesel synthesis with SO_(4)^(2-)/ZrO_(2)-Hangjin 2^(#)clay solid acid catalyst

以杭锦2^(#)土为载体,改性制备了SO_(4)^(2-)/ZrO_(2)-杭锦2^(#)土(SZ-HJ-2^(#))超强固体酸为催化剂,通过XPS、XRD、FTIR、SEM、NH 3-TPD、EDS等进行了表征分析;并基于BBD(Box-Behnken Design)实验设计方法,优化该催化剂制取生物柴油的工艺。进行了以生物柴油得率为响应值,反应温度、醇油摩尔比、催化剂用量和反应时间为自变量的优化实验。采用Design-expert 11软件对实验数据进行拟合建立了数学模型,对各因素的影响及交互作用进行了分析,该模型能够较准确地预测生物柴油的得率。通过气质联用技术(GC-MS)对生物柴油的组成进行了分析。结果表明,以杭锦2^(#)土为载体制备的SZ-HJ-2^(#)固体酸催化剂对酯交换反应具有良好的催化性能,其优化工艺为:反应温度为56℃、醇油摩尔比为8.14、催化剂用量为2.51%、反应时间为9 h,此时生物柴油得率最高,为95.46%;通过显著性分析,确定各因素影响程度顺序为:催化剂用量>反应温度>醇油摩尔比>反应时间;而催化剂用量和反应时间以及醇油摩尔比和催化剂用量交互作用显著。GC-MS分析结果表明,该生物柴油主要由棕榈酸甲酯、硬脂酸甲酯、油酸甲酯、亚油酸甲酯、亚麻酸甲酯组成。

SO_(4)^(2-)/ZrO_(2)-Hangjin 2^(#)(SZ-HJ-2^(#))solid acid catalyst was prepared by modifying Hangjin 2^(#)clay as carrier.It was characterized and analyzed by XPS,XRD,FTIR,SEM,NH 3-TPD,EDS;the process of biodiesel production with SZ-HJ-2^(#)solid acid as catalyst was optimized by the BBD(Box-Behnken Design)experimental design method.The effects of reaction temperature,molar ratio of methanol to oil,catalyst dosage and reaction time on the yield of biodiesel were investigated.The mathematical model was established by fitting the experimental data with Design-expert 11 software,and the influence and interaction of various factors were analyzed.The model can accurately predict the yield of biodiesel.The composition of biodiesel was analyzed by gas chromatography-mass spectrometry(GC-MS).The results showed that the optimum reaction conditions were as follows:reaction temperature 56℃,molar ratio of methanol to oil 8.14∶1,catalyst dosage 2.51%,reaction time 9 h.Under these conditions,the highest yield of biodiesel was 95.46%;by significance analysis,the order of influence degree of each factor is:catalyst dosage(%)>reaction temperature>molar ratio of methanol to oil>reaction time.The interaction between the amount of catalyst and reaction time,the molar ratio of methanol to oil and catalyst dosage was significant.GC-MS Analysis showed that the biodiesel was mainly composed of methyl palmitate,methyl stearate,methyl oleate,methyl linoleate and methyl linolenate.