Process and apparatus for the separation of a stream containing carbon dioxide, water and at least one light impurity including a separation step at subambient temperature

A process for the separation of a stream containing carbon dioxide, water and at least one light impurity including a separation step at subambient temperature, the process comprising the steps of:

• i. purifying a feed stream in an adsorption unit to remove water and form a dried compressed stream;
• ii. cooling the dried compressed stream or a stream derived therefrom to a subambient temperature and separating by partial condensation and/or distillation in a separation apparatus;
• iii. removing a liquid enriched in carbon dioxide from the separation apparatus;
• and
• iv. regenerating the adsorption unit using a regeneration gas;
• v. wherein the regeneration gas is formed by separating, by permeation in a permeation unit, the dried compressed stream or a gas derived therefrom, the permeate of the permeation unit constituting the regeneration gas,
• wherein the stream containing carbon dioxide, water and at least one light impurity is compressed in a compressor comprising at least two stages to form the feed stream and the feed stream contains at least 65 mol. % carbon dioxide.