METHOD FOR CLEANING GASES FROM NITROGEN OXIDES Russian patent published in 1996 - IPC

FIELD: gas cleaning in production of nitric acid, processes involved in denitration of acids and combustion of fuel. SUBSTANCE: gases with admixtures of nitrogen oxides of variable concentration are passed through a layer of catalyst consisting of, at least, two parts. Periodically introduced between catalyst parts into cleaned gases is ammonia. Direction of gases flow through catalyst is periodically reversed. At least during one cycle, ammonia is admitted in the amount exceeding the amount required stoichiometrically. Intervals between ammonia introductions equal, at least, one cycle; in this event, used is ammonia adsorbed in the previous cycle. EFFECT: higher efficiency. 1 tbl