Patent ID: 8137435
Filing Date: 2012-03-20
Classification: B01D,B01J,Y02C

Abstract:
1. A method of purifying gaseous carbon dioxide from a gaseous mixture comprising 5% to 25% by volume carbon dioxide, said method comprising (a) obtaining a gaseous mixture from a flue gas at a low pressure of 1 to 5 atmospheres absolute; (b) flowing the gaseous mixture into an adsorbent bed of a vacuum swing adsorption unit having one or more adsorbent beds in which carbon dioxide is adsorbed; (c) using a vacuum pump to draw a carbon dioxide-rich stream from the adsorbent beds; (d) directing the carbon dioxide-rich stream through a compressor to produce a compressed carbon dioxide-rich stream; (e) flowing the compressed carbon dioxide-rich stream into a gas purification unit to produce a carbon dioxide product and a carbon dioxide-lean stream, the gas purification unit comprising at least one gas separation membrane; and (f) returning the carbon dioxide-lean stream to the vacuum swing adsorption unit.