固体超强酸负载镧催化合成乳酸乙酯

以乳酸和乙醇为原料,在SO42-/La2O3-TiO2的催化下,以氧化钙为脱水剂,采用索氏提取器进行回流脱水合成乳酸乙酯。对影响乳酸乙酯酯化率的诸因素进行了考察。结果表明,加入脱水剂和带水剂可以显著提高乳酸乙酯的产率。适宜反应条件为:SO42-/La2O3-TiO2中La3+浓度为0.07 mol/L,陈化14 h,在450℃下焙烧3 h;醇∶酸(摩尔比)=2∶1,催化剂用量为乳酸质量的2.0%,带水剂苯25 mL/0.1 mol乳酸,反应3 h时,酯化率达84.2%。且该催化剂有良好的重复和再生性。

Catalytic synthesis of ethyl lactate by lanthanum solid superacid SO42-/TiO2/La2O3

Ethyl lactate was synthesized starting from lactic acid and ethanol over solid super-acid SO~(2-)_4/ TiO_2/La_2O_3 catalyst.The reaction was carried out in a Soxhlet extracting set with CaO as dehydrating(agent).The influence factors were investigated.The results showed that the productivity of ethyl lactate was obviously improved by adding dehydrating agent and water-carrying agent in the reaction system.The appropriate conditions were as follows:SO_4~(2-)/TiO_2/La_2O_3 was made by 0.07 mol/L La~(3+),aging time was(14 h),calcinations at 450℃ for 3 h,the mole ratio of alcohol to acid was 2∶1,reaction time was 3 h,catalyst amount was 2% of lactic acid mass,water-carrying agent(benzene) was 25 mL/0.1 mol lactic acid,reaction time was 3 h and esterification yield of ethyl lactate was about 84.2%.And the catalyst was reused and regenerated.