Esterification of lactic acid with n-butanol by reactive distillation

Esterification of lactic acid with n-butanol may be performed to synthesize n-butyl lactate or to recover lactic acid from its aqueous solution. In the present work, the reaction is performed in the presence of cation-exchange resins as a catalyst. Kinetic parameters like activation energy and the rate constants are estimated using the pseudohomogeneous model. The applicability of reactive distillation for this reaction is evaluated through experiments using batch and continuous reactive distillation techniques. An equilibrium stage model is formulated, and simulation results are compared with the experimental results. Further, the effects of operating parameters like feed mole ratio, catalyst loading, and boilup rate are evaluated on the conversion of lactic acid in batch reactive distillation. Experimental results of continuous reactive distillation are compared with the simulation results observed using the Aspen plus process simulator. Effects of operating variables were studied with the help of the experimentally validated model. A continuous reactive distillation process for the recovery of lactic acid is proposed.