DISTILLATIVE SEPARATION OF ACID GASES FROM LIGHT HYDROCARBONS

摘要

The invention is concerned with a distillative method of separating in a distillation apparatus a mixture containing carbon dioxide and a light hydrocarbon into a carbon dioxide rich overhead fraction and a light hydrocarbon rich fraction, the conditions of distillation being such that the carbon dioxide and light hydrocarbon are liable to form an azeotrope therebetween. The method of the invention is characterized in that an additional liquid component is added to the mixture under distillation at a point above the feed to the distillation apparatus, which liquid component significantly alters the relative volatility between the carbon dioxide and the light hydrocarbon so that the volatility of the carbon dioxide is maintained above that of the light hydrocarbon at all points at and below the point of introduction of the liquid component, whereby the concentration of carbon dioxide in the overhead fraction exceeds the azeotropic composition. The invention allows a more complete separation to be achieved.