Patent ID: 6740302
Filing Date: 2004-05-25
Classification: C01B,C01P

Abstract:
A process for producing high purity sulfuric acid comprising:a) adding hydrogen peroxide solution having a concentration of 1-70% to 24-70% technical grade oleum in a sufficient amount to lower the SO2 concentration to below 10 ppm, b) evaporating SO3 in the oleum at 90-130Â° C. in a falling film evaporator, c) removing traces of sulfuric acid and nitrosyl sulfuric acid from the resultant SO3 gas stream escaping from the evaporator by means of a demister, d) enriching the high purity SO3 with inert gas, and e) absorbing the SO3 in sulfuric acid at a concentration of 90-99% to form said high purity sulphuric acid.