Hybrid carbon dioxide separation process and system

The present application relates to separation processes and systems and more specifically to hybrid carbon dioxide separation processes. In one embodiment, the system for the separation or removal of carbon dioxide comprises an apparatus (11) for a selective separation of carbon dioxide (CO) from flue gas - typically exhaust gases, syngas or natural gas streams - using one or more so-called CO reverse selective membrane(s) in the first separation unit (11) to enrich a feed gas stream (10) which contains carbon dioxide with CO, and by separating other constituents of the gas stream. Thus, the feed gas stream is separated in the first separation unit by CO-reverse-selective separation into a CO-lean gas stream (12) and a CO-enriched gas stream (13). The CO-enriched gas stream (13) is fed to a second separation unit which is a CO-selective separation unit (14). The second separation results in a purified CO-rich gas stream (15) and a remaining CO-lean gas stream (16).