An extracorporeal circuit for removing CO2 from blood comprising a blood taking line for taking blood from the patient, an oxygenation assembly and a blood re-introduction line for re-introducing blood into the patient. The oxygenation assembly comprises an oxygenator, a dialyzer arranged upstream of the oxygenator, a circulation circuit for the circulation of a dialyzer bath connected to the dialyzer and an acidifier arranged to introduce an acid substance into the circulation circuit for circulation of the dialyzer bath.
