| 摘要 |
<p>A gas mixture comprising carbon dioxide, at least one gas having a lower boiling point than carbon dioxide, and at least one gaseous impurity (typically hydrogen sulphide) having a higher boiling point than carbon dioxide is cooled to the dew point of the carbon dioxide or below in a heat exchanger (1). The gas mixture is then passed into a rectification column (4) fitted with a condenser (5). In the rectification column (5) a product gaseous fraction free from the impurity and a liquid fraction containing the impurity are produced. Pure carbon dioxide may be obtained as a gaseous fraction in a second rectification column (8).</p> |
