Process for the continuous performance of exothermic reactions in a fixed-bed circulation reactor

摘要

A process is proposed by which it is possible to generate a circulating reaction zone in a fixed-bed circulation reactor even under unfavourable conditions and to maintain it with minimal operating costs. This is achieved by the gas stream being led off from the fixed-bed circulation reactor in the start-up phase downstream of the reactor section and upstream of the heat exchanger section. A minimisation of operating costs is possible by reduction or avoidance of the volume of catalyst in the circulation line and by using catalytically active static mixers. The use of static mixers has the advantage that a flow virtually free of dead space is generated, the heat transfer in the heat exchanger section is improved and the pressure drop is decreased. The process is particularly suitable for the autothermal treatment of exhaust gases or exhaust air having low contents of gaseous pollutants and/or low loadings of combustible organic dusts and/or fluid particles. An improvement of the gasification of the organic dusts can be achieved by additional feed of oxygen into the exhaust air stream used.