Synthesis of n-butyl lactate catalyzed by rare composite solid superacid SO_4~(2-)/ZrO_2-Nd_2O_3

N-butyl lactate was synthesized from lactic acid and n-butyl alcohol with rare earth solid superacid SO42-/ZrO2-Nd2O3 as catalyst,The effect of primary factors on esterification was investigated by orthogonal design experiment,The results showed that the optimum reaction conditions were:based on 0.1 mol lactic acid,molar ratio of n-butyl alcohol to lactic acid was 3.0∶1,the amount of catalyst was 0.55 g,15mL cyclohexane as water carrying agent,reaction time was 2.0 h at reflux temperature,the esterification yield was up to 98.7% under the optimum condition,rare composite solid superacid SO42-/ZrO2-Nd2O3 catalyst can be reused by simple phase-separation,the esterification yield was still up to 96% after the catalyst was reused 7 times.