Cryogenic separation of a carbon dioxide-rich gas mixture, especially natural gas

摘要

Cryogenic separation of a low boiling CO2-rich gas mixture is carried out by rectification using a highly thermally conductive a gas permeable layer, within which a solid CO2 layer is formed. Cryogenic separation of a low boiling CO2-rich gas mixture is carried out using a highly thermally conductive a gas permeable layer by (a) introducing an expanded gas/liquefied gas mixture at the lower end of a rectification column; (b) simultaneously passing an additional coolant around and/or through the layer to cause solid CO2 formation in the layer; and (c) simultaneously producing different rectification zones with different temperature and pressure ranges. An Independent claim is also included for equipment for carrying out the above process, the equipment including a rectification column (1) which (i) is equipped with a high pressure valve (3), a transport device (4) for the expanded gas/liquid mixture (5), an inlet (6), a differential pressure gauge (7), a regulator (8) and a medium pressure valve (9); (ii) contains a thermal separation layer (10) located above the inlet (6) and having an internally formed solid CO2 layer (11), an adjacent cooling region (12) and an overlying liquefied gas collection region (13); and (iii) includes upper and lower rectification zones (15, 17).