Method and system for carbon dioxide liquefaction

Abstract

Disclosed is a method and system to for liquefying carbon dioxide. Herein a CO2 gas stream comprising, calculated on the basis of non-condensable matter, at least 90mole % of CO2 is fed to a compression section, and compression so as to provide a liquid or supercritical fluid CO2 stream. The latter stream is divided intoa CO2process fluid, which is subjected to liquefaction, and a CO2 refrigerant fluid, which is subjected to a refrigeration cycle. The liquefaction comprises flashing the CO2process fluid followed by separation of gaseous and liquid CO2. The latter is subjected to stripping with CO2. The former is liquefied, together with used CO2 stripping gas, by condensation. The cooling thereby required, is provided by vaporization of the CO2 refrigerant fluid. The gaseous CO2resulting therefrom is returned as a feed to the compression stage.