固体酸Zr(SO4)2/TiO2催化合成棕榈酸甲酯

Synthesis of methyl palmitate catalyzed by solid acid Zr(SO4)2/TiO2

摘要:

以固体酸Zr(SO4)2/TiO2为催化剂，工业棕榈酸与甲醇为原料合成棕榈酸甲酯生物柴油。考察了Zr(SO4)2负载量、催化剂焙烧温度、焙烧时间、m(棕榈酸):m(甲醇)、催化剂用量和反应时间对酯化率的影响，并采用GC-MS、红外光谱仪、热重差热综合热分析仪对催化剂和产物进行表征分析。实验结果表明，与Zr(SO4)2催化剂相比，固体酸催化剂Zr(SO4)2/TiO2在工业棕榈酸和甲醇的酯化反应中具有较高的催化活性。最佳的反应条件为：以400 ℃焙烧制得的Zr(SO4)2负载量为65%的固体酸Zr(SO4)2/TiO2为催化剂，醇酸质量比为12:25，催化剂用量为棕榈酸质量的8%，反应时间5 h。在此条件下，酯化率可达98.9%。经GS-MS分析，酯产物主要为直链十六烷酸甲酯和十八碳烯酸甲酯。

Abstract:

Biodiesel was synthesized by industrial palmitic acid and methanol, using solid acid Zr(SO4)2/TiO2 as catalyst. Effects of mass fraction of Zr (SO4)2 in the catalyst, calcination temperature and time of catalyst, mass ratio of methanol to industrial palmitic acid, catalyst dosage and reaction time on the esterification rate were investigated. The catalyst and ester product were analysed by GC-MS, FTIR and DTG/DTA methods. Assessment experiments show that the catalytic activity of the supported Zr(SO4)2/TiO2 catalyst was higher than the unsupported Zr(SO4)2 catalyst. The esterification rate can reach at 98.9% under the following conditions: calcination temperature of catalyst 400 ℃, loading amount of Zr(SO4)2(based on total mass of catalyst) 65%, mass ratio of methanol to industrial palmitic acid 12/25, mass fraction of Zr (SO4)2/SiO2 in palmitic acid 8.0% and reaction time 5 h. Analysis result of GC-MS showed that the ester product were mainly hexadecanoic acid methyl ester and 10-octadecenoic acid methyl ester.