Liquid carbon dioxide recovery from gas mixtures with methane

Abstract From the Canadian patent

Land-fill and other gases containing principally methane and carbon dioxide have been separated into high BTU fuel gas and discard carbon dioxide containing appreciable methane. Such discard gas can now be simply fractionated into high-purity liquid carbon dioxide with recoveries in excess of 80% while using a single refrigerant at a single low temperature to satisfy all refrigeration requirements of fractionation. This novel fractionation is ideally combined with the process of separating landfill gas into high BTU fuel gas because then the methane and carbon dioxide are recovered completely as two valuable products, high BTU fuel gas and pure liquid carbon dioxide.