METHOD FOR PRODUCTION OF NITRIC ACID Russian patent published in 2005 - IPC

FIELD: mineral acid manufacturing, in particular method for production of 50-70 % nitric acid from nitrous gas.

SUBSTANCE: claimed method includes ammonia catalyst oxidation and nitrogen oxides absorption from nitrous gas with water and nitric acid, wherein nitrogen oxides absorption in absorption unit is carried out by using mass-exchange elements having several absorbing zones with different surfaces. Ratio (n) of oxidized nitrogen monoxide (NO) and absorbed nitrogen dioxide (NO₂) in determined according to equation: lg n = (0.22-0.29)-0.0626 lg PNO_x, wherein PNO_x is partial pressure of nitrogen oxides in nitrous gas. According the invention it is made possible to increase absorption ratio and reduce nitrogen oxide content in exhaust gas up to 0.005 vol.%.

EFFECT: environmental friendly method with improved nitrogen oxide absorption.

3 tbl