Selective catalytic reduction of NO x over zeolite-coated structured catalyst packings

Abstract

In this work, the performance of two configurations of in situ zeolite-coated structured catalyst packings is treated. Just to demonstrate the reactor concepts, the catalyst packings were tested on a bench scale in the selective catalytic reduction of NO with excess ammonia. The performance of Cu-ZSM-5-coated ceramic slabs that were placed in a parallel passage array (PPR) was compared with a Cu-ZSM-5 monolith. Practical correlations are given for pressure drop, diffusion and the overall performance of the reactor. According to a simple model, the catalyst effectiveness factor of the PPR turned out to be 17%, whereas that of the monolith was 95%. The plate thickness and the spacing of the parallel plates proved to be of paramount importance for optimum catalyst efficiency. For practical evaluation and comparison with known NO x reduction units, more realistic reaction conditions should be chosen.