| abstract |
A process and apparatus for producing liquid carbon diox-ide is disclosed. A process stream (60) which comprises carbon di-oxide and a balance substantially of nitrogen and water is cooled (70, 90). The process stream is compressed (130) so that all but trace amounts of water is condensed out, cleaned (240) to remove trace amounts of water, long-chain hydrocarbons and particu-lates, and separated (260) into a nitrogen-rich gaseous stream (270) which is expanded (300) to produce an expanded nitrogen-rich gaseous stream and a carbon dioxide-rich gaseous stream (280) which is compressed (290). The energy of expanding is used to compress the carbon dioxide-rich gaseous stream. The com-pressed carbon dioxide-rich gaseous stream is cooled (330) by the expanded nitrogen-rich gaseous stream to liquefy the carbon di-oxide and reduce the temperature of the gaseous nitrogen in the stream. The liquefied carbon dioxide (380) is withdrawn as pro-duct. |