The pervaporation (PV) reactor is a new technology for reaction and separation. Techno-economic studies are showing that PV reactors have good market potential. The most common reaction system studied for the application of PV is an esterification reaction between an alcohol and an acid in the presence of a catalyst. In the present paper, modeling and simulation of a PV reactor for esterification of lactic acid with ethanol were studied. The experimental data were used for the model validation and excellent agreement was found. The effect of several process variables such as temperature, initial mole ratio of reactants, ratio of the effective membrane area to the volume of reacting mixture, catalyst concentration, and flux on conversion of reactants were studied. The conversion of lactic acid was enhanced in a PV reactor as compared to a conventional reactor. The PV reactor has a good potential for enhancing conversion in reversible condensation reactions (especially esterification), generating water as a product. Optimum conditions were observed at temperatures of 75 to 95 degrees C for S/V of 10 m (1), for a catalyst concentration of 30 g/l for a reactant ratio (acid/alcohol) of 2. The model can be used for the other esterification reactions in a PV reactor.