Treatment of flue gas from an oxyfuel combustion process

A method for removing carbon monoxide (CO) and NOx from flue gas comprising carbon dioxide, CO, NOx and at least one non-condensable gas, said method comprising:

• generating said flue gas by oxyfuel combustion of a fuel in an oxyfuel combustion system;
• contacting said flue gas, or a CO-containing gas derived therefrom comprising nitric oxide (NO), at a first elevated temperature and at a first elevated pressure, with at least one catalyst bed comprising a CO-oxidation catalyst in the presence of oxygen (O2) to convert CO and NO to carbon dioxide and nitrogen dioxide (NO2) respectively and produce carbon dioxide-enriched gas comprising at least a portion of said condensable gas(es) and enriched in NO2;
• removing at least a portion of said NO2 from said carbon dioxide-enriched gas, or from a NO2-containing gas derived therefrom, by adsorbing NO2 in at least one adsorbent bed to produce NO2-depleted gas;
• regenerating said adsorbent bed(s) using a regeneration gas to produce NO2-enriched regeneration gas;
• and
• recycling said NO2-enriched regeneration gas to said oxyfuel combustion system.