Catalytic synthesis of ethyl lactate by lanthanum solid superacid SO_4~(2-)/TiO_2/La_2O_3

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.