Patent ID: 7582271

Claim:
A method of treating a gas stream for removal of at least oxides of sulfur, the method comprising: scrubbing the gas stream with a first hydrogen peroxide solution, thereby producing a first scrubber liquor; measuring a hydrogen peroxide concentration in the first scrubber liquor; maintaining a desired hydrogen peroxide concentration in a scrubbing mixture of the first hydrogen peroxide solution and a recycled first scrubber liquor by regulating a flow of the first hydrogen peroxide solution in response to the measured hydrogen peroxide concentration of the first scrubber liquor; removing a by-product stream containing sulfuric acid after attaining a desired sulfuric acid concentration in the first scrubber liquor; after scrubbing the gas stream with the first hydrogen peroxide solution, oxidizing the gas stream using a second hydrogen peroxide solution in an oxidation process adapted to convert nitric oxide to nitrogen dioxide, using catalytic decomposition of the second hydrogen peroxide solution to produce oxidative species that convert nitric oxide to nitrogen dioxide; and after oxidizing the gas stream, scrubbing the gas stream with a third hydrogen peroxide solution and removing a by-product stream containing nitric acid; wherein the second hydrogen peroxide solution is concentrated to a level of approximately 75% or more by volume prior to use in oxidizing the gas stream.