METHOD FOR JOINT PRODUCTION OF HIGH-PRESSURE NITRIC ACID WITH LOW-PRESSURE NITRIC ACID

摘要

The invention relates to a method for possible joint production of industrial quality high-pressure nitric acid and low-pressure nitric acid. When preserving the normal function of the absorption unit, operating at high pressure, nitric acid in it is further concentrated to concentration under 45%, produced at low pressure. The method requires no new plant for producing nitric acid with the desired concentration of 58-60%. The method is realized when two flows are fed to the absorption column. The first flow, with NHO3 concentration of 26-28%, produced in a cooler-condenser, is introduced at a higher tray (14th - 15th), and the second of 42-45% nitric acid concentration is sent to the 6th-8th tray. By the method the productivity increases by 40% of the process of producing nitric acid with 59-60% concentration and NOx concentration after the absorption column 200 ppm under winter conditions and 400 ppm in summer conditions. 3 claims