Periodic operation of the Deacon process

The problems arising in two step Deacon process are corrosion, space;time yield, chlorine purity, catalyst deactivation and overheating of the catalyst. Avoiding adsorption of hydrogen chloride on the catalyst carrier and limiting the maximum temperature, periodic operation with sufficient space time yield and chlorine purity is possible. To overcome corrosion problems a two-step adiabatic fixed-bed process was developed. Dynamic simulations showed that periodic flow reversal causes overheating, but with cocurrent operation it is possible to keep temperatures in the required range. The dynamics of the process are dominated by a travelling temperature and reaction front. A simple analytical model can be derived to calculate the most interesting features directly. (C) 1999 Elsevier Science Ltd. All rights reserved.