Testing catalysts for production performance and runaway limits

Abstract

The results of laboratory catalyst tests, conducted in recycle reactors under fixed conditions of feed rate and composition and otherwise at average production conditions, permit the evaluation of catalyst performance for production reactors. These tests are performed in short steady-state runs at stepwise increasing temperatures until a specified product concentration is reached. From these results, in addition to performance evaluation, the thermal stability criteria of the reaction can also be calculated. This information is needed to maximize production within the thermal runaway limit. Since the thermal runaway limit, estimated from the catalyst test, does not contain assumptions on kinetics, the experimentally evaluated runaway limit can be used as a benchmark to help discriminate between kinetic models that were developed from other data sets. The evaluation of the performance as well as the thermal runaway limit is shown on actual experimental measurements made for the production of ethylene oxide by oxidation of ethylene.