Nitric acid production

Abstract

Provided is a process having an increased production capacity for nitric acid, which moves can be operated safely and efficiently. The process comprises forming a reaction mixtures by mixing air, ammonia, oxygen and an inert cooling fluid, preferably water, and then reacting the ammonia with oxygen in a reaction zone to form nitric oxide. The amount of inert cooling fluid in the reaction mixture is sufficient to control the temperature of the mixture and maintain the ammonia percentage below the lower explosion limit for the mixture. The nitric oxide produced in the reaction zone is then oxidized to nitrogen dioxide and its dimer, with additional oxygen being introduced into the process for oxidizing the nitric oxide. The nitrogen dioxide and its dimer is then reacted with water to form the nitric acid. The dual injection of oxygen into the ammonia reaction mixture and into the nitric oxide oxidizing step, together with the use of the inert cooling fluid in the ammonia reaction mixture, has been found to provide increased nitric acid production while allowing one to respect the constraints of good product bleaching, avoid catalyst loss due to volatilization, and operate under conditions below the lower explosion limit of the ammonia mixture.

Dependencies are inferred from the claim text.