Method for carbon dioxide recovery from a feed stream

Abstract

The method of the invention recovers CO.sub.2 from an inlet cold feed stream containing a low concentration thereof, and includes the following steps. An inlet feed stream is passed through a heat exchanger, against a compressed flow of the inlet feed stream, to cool the compressed flow. The compressed flow is further cooled and compressed to a high pressure, fed to a distillation column and there converted into a vent gas including CO.sub.2 and a high purity bottom liquid CO.sub.2. A first portion of the bottom liquid CO.sub.2 is expanded to achieve a first cooled liquid CO.sub.2 refrigerant flow, which is then vaporized against the vent gas to recover condensed CO.sub.2 therefrom. The condensed CO.sub.2 is then reintroduced into the distillation column. A second portion of the bottom liquid CO.sub.2 is expanded to achieve a second cooled liquid CO.sub.2 refrigerant flow, which is then used to subcool the CO.sub.2 product output.

Dependencies are inferred from the claim text.