SCRUBBING SYSTEM

摘要

A method of removing nitrogen oxides and sulphur oxides from a flue gas emitted by an oxyfuel combustion process comprises the steps of: (i) supplying a flue gas from an oxyfuel combustion process, the flue gas comprising nitrogen oxides and sulphur oxides contaminants; (ii) oxidising nitric oxide present in the flue gas to form nitrogen dioxide; (iii) contacting the flue gas with a solution comprising water and ammonia to produce ammonium sulphate, ammonium nitrate and an exhaust gas substantially free of nitrogen oxides and sulphur oxides; and (iv) separating the exhaust gas, the ammonium sulphate and the ammonium nitrate produced in step (iii) from the solution comprising water and ammonia; in which the pH of the solution comprising water and ammonia is maintained above (8) during step (iii).