Method for carbon dioxide recovery from a feed stream

摘要

The method of the invention recovers CO2 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 CO2 and a high purity bottom liquid CO2. A first portion of the bottom liquid CO2 is expanded to achieve a first cooled liquid CO2 refrigerant flow, which is then vaporized against the vent gas to recover condensed CO2 therefrom. The condensed CO2 is then reintroduced into the distillation column. A second portion of the bottom liquid CO2 is expanded to achieve a second cooled liquid CO2 refrigerant flow, which is then used to subcool the CO2 product output.