The production of (S)-ibuprofen acid was studied in a hollow fiber membrane reactor, with the aim to develop a clean and ecofriendly technology. The modeling and simulation of enzymatic membrane reactor was studied for lipase-catalyzed hydrolysis of racemic ibuprofen ester in hollow fiber membrane reactor. Mathematical model was developed to simulate the behavior of enzymatic reaction in the membrane matrix region. The model equation was derived considering reaction over immobilized enzyme in the membrane porous support with the substrate flowing along the shelf side. The model was simulated on the basis of experimental operating conditions, physical and hollow fiber geometrical parameters. The model equation was a nonlinear second-order differential equation and solved numerically using Matlab. The parameters studied were Thiele Modulus (Phi(2)), Bodenstein number (B-0), transmembrane pressure (TMP) and intrinsic enzyme kinetic constants (V-max and K-m). Simulation results showed that a satisfactory product separation was achieved with 60 % conversion of (S)-ester, enantiomeric excess of substrate, ee(s) in the range 35-43 %, enantiomeric excess of product, ee(p) in the range 80-85 %, and enantiomeric ratio (E value) of 11.2-15.3 at 4.34 < B-0 < 13.89 and Phi(2) < 1. The simulated results agreed with the experimental data within an error of +/- 7.5 %. The reaction-separation functionality of EMR system has shown the potential of membrane reactor application for kinetic resolution of racemic compounds especially in overcoming the difficulties associated with conventional technology particularly in downstream separation and enzyme recovery. (C) 2004 Elsevier Ltd. All rights reserved.