This article presents the modeling and optimization of an industrial batch reactor operation with regard to production safety constraint which is represented by the reactor content swelling. Swelling occurs due to the evacuation of a coupled product which passes through the liquid in order to reach the reaction mass surface. In order to model the reaction system a chemical model linked to a hydrodynamic model is developed. The goal of the optimization is to calculate the temperature and pressure profiles which maximize conversion rates, without exceeding the maximum reactor level. The optimal temperature profile is calculated using the optimal control optimization method and the results show that a productivity increase of up to 36% can be achieved as compared to the industrial process. (C) 2007 Elsevier Ltd. All rights reserved.