Patent ID: 8012446

Claim:
A method for removing at least nitrogen dioxide (NO 2 ) from a carbon dioxide feed gas comprising NO x and at least one “non-condensable” gas as contaminants, said method comprising: passing said carbon dioxide feed gas at a first elevated pressure through a first adsorption system that selectively adsorbs at least NO 2 to produce at least substantially NO 2 -free carbon dioxide gas, said first adsorption system comprising at least one adsorbent bed; purifying said at least substantially NO 2 -free carbon dioxide gas to produce purified carbon dioxide and carbon dioxide-lean vapor comprising at least a major portion of said non-condensable gas(es); recovering carbon dioxide from said carbon dioxide-lean vapor at a second elevated pressure to produce carbon dioxide-rich gas and carbon dioxide-depleted gas that is rich in said non-condensable gas(es); and using at least a portion of said carbon dioxide-rich gas to regenerate at least a portion of said adsorbent bed(s) of said first adsorption system and produce NO 2 -enriched regeneration gas.