叔丁基甘油醚的催化合成研究

Catalytic synthesis of tert-butyl glycerol ether

甘油是一种可再生资源,作为柴油生产过程中的副产物,每年大量剩余,以甘油为原料制成的叔丁基甘油醚常用作燃料添加剂,可显著降低其黏度。为提高多取代叔丁基甘油醚的得率,以叔丁醇(TBA)和甘油(G)为原料,4A分子筛为脱水剂,经醚化反应液相体系下合成了叔丁基甘油醚,通过GC、GC-MS等方法对产物进行分析,探讨了催化剂种类及其用量、脱水剂用量、反应时间等因素对合成叔丁基甘油醚的影响,并确定了叔丁基甘油醚的合成工艺条件。结果表明:在异长叶烯酮磺酸的催化作用下,当催化剂用量为0.17 g/g,脱水剂用量为0.8 g/g,投料比n(G)∶n(TBA)为1.0∶4.5,反应时间12 h时,甘油转化率为79.87%,其中,多取代叔丁基甘油醚的得率为71.74%。该方法操作简单,催化剂绿色环保,可显著提高多取代叔丁基甘油醚的得率。

As one of the main by-products in the process of biodiesel production,glycerol is a renewable resource. At present,the price of glycerol fell sharply along with the development of biodiesel. Therefore,finding the newapplication field of glycerol is one of the hot issues. Tert-butyl glycerol ether,which was synthesized by using glycerol as the rawmaterial,is a newtype of green and renewable fuel additives. This additive can not only significantly reduce the discharges of inhalable particle,hydrocarbons,and carbon monoxide from the vehicles,but also improve the combustion efficiency of diesel fuel. Furthermore,the tert-butyl glycerol ether can also reduce the viscosity of diesel. Therefore,the tert-butyl glycerol ether can gradually replace the traditional petroleum-based additives. In this study,we took tert-butanol（ TBA） and glycerol（ G） as rawmaterials and 4 A molecular sieve as dehydrating agent,and the tert-butyl glyceryl ether was synthesized by etherification reaction under liquid phase system. The product was analyzed by GC and GC-MS. The effects of catalyst type and dosage,dosage of dehydrating agent and reaction time on the synthesis of he tert-butyl glyceryl ether were discussed. The synthesis conditions of the tert-butyl glyceryl ether were also determined. The results showed that when the mass of the catalyst was 17% of the mass of the glycerol,the quality of the dehydrating agent was 80%,the feed ratio n（ G） ∶ n（ TBA） was 1. 0 ∶4.5,and the reaction was carried out under the catalysis of isolongifolenone sulfonic acid. The conversion of glycerol was 79. 87% at 12 h,with71. 74% of the yield of multi-substituted tert-butyl glyceryl ether. The method of this study is simple and the catalyst is green and environmently friendly,which can obviously improve the yield of multi-substituted glycerol ether.