Carbon dioxide capture system comprising a compressor and an expander and a method of using such a system

A CO2 capture system comprising:

• an intake (6) for CO2-rich exhaust gas (6g) from a first source to a compressor (2) and one or more outlets (5) for a compressed, first CO2-rich gas (6r) under pressure (P) to a first manifold (8) to a shell (10) enclosing at least parts of a combustion chamber (11) with a wall (11w), the combustion chamber (11) comprising burners (13) arranged to burn fuel (14f) and compressed air (15c) supplied under pressure (P) from a fuel line (14) and a compressed air line (15), respectively, to form a second CO2-rich gas (15r) in burners (13) without mixing with the first CO2-rich gas (6g) from the compressor (2),
• slits (12) in the wall (11w) in the combustion chamber (11) to let in the compressed, first CO2-rich gas (6r) to mix with and cool the second CO2-rich gas (15r) formed in the burners (13) to form a third CO2-rich exhaust gas (60r);
• a heat exchanger (16) arranged to operate under pressure (P) and to heat exchange the hot third CO2-rich exhaust gas (60r) from the combustion chamber (11), and out via a pipe (17) to a CO2 extraction plant (100), with returning CO2-poor exhaust gas (60L) from the CO2 extraction plant (100) via a line (18) under pressure (P) to form returned heated CO2-poor exhaust gas (60L),
• a second manifold for leading the returned, now heated CO2-poor exhaust gas (60L) back to an expander (3) that drives the compressor (2) and the CO2 extraction plant (100), and out via an outlet (7).