Optimization of Radial Flow Reactors of Styrene Production

Abstract

A mathematical model is developed to optimize the performance of the radial flow reactors of styrene production through an oxidative reheat process. The model integrates the hydrodynamic configuration of the reactors with the underlying chemical reactions where the kinetic expressions were found in the literature. The predictions of the model were compared with the actual plant data and satisfactory results were obtained. In order to optimize the performance of the plant, a combination of yield and selectivity styrene was adopted as the objective function. The global criterion multi-objective method using Levenberg-Marquardt algorithm was used in order to search for the optimal solution of the process. Three main process variables, i.e., the flow rate of steam injected to the second and third reactor and the fraction of oxygen injected to the secondary injection port of the second reactor, were determined in the optimization. The results show that the optimal operating conditions may lead to 2.6 % increase in the styrene yield and 1.5% increase in styrene selectivity, which significantly improves the profitability of the whole styrene production process.