新型柴油十六烷值改进剂草酸二异丁酯的合成

Synthesis of a New Type Cetane Number Improver——Di-Isobutyl Oxalate

以草酸和异丁醇为原料,在酸性催化剂作用下进行酯化反应合成出一种新型柴油十六烷值改进剂——草酸二异丁酯。分别考察了硫酸氢钠和对甲苯磺酸对该反应的催化性能,确定了各自的最佳合成条件。以硫酸氢钠为催化剂,在n(醇)∶n(酸)=2.2∶1、ω(催化剂)=6%、带水剂40 mL、反应时间120 min条件下,草酸二异丁酯的产率可达96.3%;以对甲苯磺酸为催化剂,在n(醇)∶n(酸)=2.4∶1、ω(催化剂)=2%、带水剂35 mL、反应时间100 min条件下,草酸二异丁酯的产率可达92.1%。在以硫酸氢钠为催化剂时,催化剂重复使用5次,产率变化不大。

In this paper, di-isobutyl oxalate was prepared from oxalic acid and isobutyl alcohol using NaHSO4 and p-toluenesulfonic acid as catalysts. The influence of temperature, catalyst and the molar ratio of raw materials on the yield of the product were studied. Experimental result showed that the optimum conditions were as follows; the material molar ratio （alcohol/acid） were 2.2 ： 1 and 2.4 ： 1 ,the catalyst content were 6% and 2% ,the reactiom time were 120 min and 100 min,the water-carrying agent were 40 mL and 35 mL,while the yields of product for NaHSO4 and p-toluenesulfonic acid were 96.3% and 92. 1%,respectively. When the catalyst NaHSO4 was reused for five times,the product yield was still very high.