Reduction of nitrogen oxide(s) emission from nitric acid plant - by reducing working temp. to prevent decomposition of nitrous acid

摘要

Method of reducing the nitrogen oxides content of residual or tail gases from mfr. of nitric acid without adding diluent air, to 100 ppm (vol.) with reduced energy cost consists of holding the gas at 10 degrees C (4 degrees C) in contact with water, ensuring that the gas contains >=2% O2. New limits of emission of nitrogen oxides ( 200 ppm by vol.) can be complied with, the amt. of nitrogen oxides being released after the treatment being 100 ppm by vol.