Exhaust gas processing system and processing method

(22) 20.01.2017

(43) 09.02.2017

(57) There is disclosed an exhaust gas processing system, comprising: a desulfurization unit (2) that removes a sulfur oxide from an exhaust gas by a limestone/gypsum method; a denitration unit (3) arranged in a subsequent stage from the desulfurization unit (2) to remove a nitrogen oxide from the exhaust gas; a carbon dioxide recovery unit (4) arranged in a subsequent stage from the denitration unit (3) to recover carbon dioxide from the exhaust gas; and an oxygen supply unit that supplies a fraction of a post-recovery gas discharged from the carbon dioxide recovery unit (4), as an oxygen source, to the desulfurization unit (2), wherein the oxygen supply unit comprises: a monitor (79) having an analyzer (75) for monitoring the purity and the recovery ratio of the recovered carbon dioxide recovered by the carbon dioxide recovery unit (4), and an adjusting apparatus (73, 74) that adjusts the proportion of the fraction of the post-recovery gas to be supplied to the desulfurization unit (2) in the post-recovery gas discharged from the carbon dioxide recovery unit (4), based on the purity and the recovery ratio of the recovered carbon dioxide which are monitored by the monitor (79).

(71) IHI Corporation