Catalytic synthesis of flavor n-butyl lactate by rare earth composite solid superacid

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