Integration of catalytic CO2 oxidation and oxyfuel sour compression

Abstract

Sulfur dioxide (SO2) may be removed from carbon dioxide feed gas by contacting the carbon dioxide at an elevated temperature and an elevated pressure with a catalyst for oxidizing SO2, in the presence of oxygen (O2) to convert SO2 to sulfur trioxide (SO3); contacting SO3 in the resultant SO3-enriched carbon dioxide gas with water to produce sulfuric acid and SO2-depleted carbon dioxide gas; and separating the sulfuric acid from the SO2-depleted carbon dioxide gas. If present, NOx is also removed from the carbon dioxide feed gas as nitric acid to produce SO2-depleted, NOx-lean carbon dioxide gas. The method has particular application in the removal of SO2 and NOx from flue gas produced by oxyfuel combustion of a hydrocarbon fuel or carbonaceous fuel, within or downstream of the CO2 compression train of a CO2 recovery and purification system.

Dependencies are inferred from the claim text.