Regeneration of commercial SCR catalyst deactivated by arsenic poisoning in coal-fired power plants

Abstract

Arsenic species, which are inevitable components in flue gas from the coal combustion process, will result in severe deactivation of selective catalytic reduction (SCR) catalysts. In this paper, a novel method is proposed to regenerate the arsenic-poisoned commercial V2O5-MoO3/TiO2 catalyst collected from coal-fired power plants, including ammonia washing, H2 reduction, and air calcination. Activity tests indicated that the proposed method could recover the catalyst activity more than 96% of the fresh catalyst. Furthermore, detailed characterizations results indicated that this regeneration method could not only effectively remove the arsenic species, but also recover the active constituents of the catalysts to a considerable level. The proposed method offers a feasible strategy for the regeneration of poisoned commercial SCR catalysts and can effectively reduce the total denitrification cost for coal-fired power plants.