Patent ID: 8535417

Claim:
A method for recovering carbon dioxide comprising (A) providing a carbon dioxide-augmented feed gas by adding carbon dioxide to a flue gas produced by oxy-fuel combustion wherein the flue gas comprises at least carbon dioxide, water vapor, NOx and carbon monoxide, wherein the feed gas contains less than 0.1 vol. % hydrogen; (B) compressing the feed gas and then drying the compressed feed gas by contacting it with an adsorbent to form moisture-laden adsorbent and a dried gaseous feed stream; (C) subjecting the dried gaseous feed stream to a subambient-temperature recovery process, employing refrigeration provided by expansion of at least one liquid carbon dioxide product stream formed by said recovery process, to produce at least one gaseous carbon dioxide product stream and at least one gaseous carbon dioxide-containing vent stream; (D) separating the vent stream into a carbon dioxide-rich stream and a carbon dioxide-depleted stream, by pressure swing adsorption or by physical or chemical absorption; (E) desorbing moisture from said moisture-laden adsorbent by contacting said moisture-laden adsorbent with said carbon dioxide-depleted stream to form a moisture-laden carbon dioxide-depleted stream and then separating said moisture-laden carbon dioxide-depleted stream from said adsorbent; and (F) combining said carbon dioxide-rich stream with said flue gas to form said carbon dioxide-augmented feed gas.