| 摘要 |
The present invention is directed to a method for producing carbon dioxide and nitrogen from combustion exhaust gas containing less than about 10% oxygen by weight which comprises the steps of (a) treating the exhaust gas to remove particulate matter, (b) compressing the exhaust gas to a pressure in the range from about 25 psia to about 200 psia, (c) purifying the exhaust gas to remove trace contaminants, (d) separating the exhaust gas to produce a carbon dioxide rich fraction and a nitrogen rich fraction, (e) liquifying the carbon dioxide rich fraction and distilling off volatile contaminants to produce pure carbon dioxide, (f) purifying the nitrogen rich fraction to remove contaminants, and (g) cryogenically fractionally distilling the nitrogen rich fraction to produce pure nitrogen. In another embodiment, the invention is directed to a method for producing carbon dioxide, nitrogen, and argon from a combustion exhaust gas. The combustion exhaust gas in the present invention may be obtained from an ammonia plant reformer furnace and the nitrogen produced may be employed as a synthesis gas in the ammonia reactor.
|
