Carbon dioxide is separated from a gas mixture via two scrubbing columns. The gas mixture consisting of nitrogen, hydrogen and carbon dioxide passes through a gas pipeline into the first stage gas scrubber. An added solvent, usually aniline, binds with the carbon dioxide, which is then forwarded in liquid form to a gas scrubber or ‘desorber’ where it is “washed” out of the liquid. The process pressure is monitored during the absorption process, which takes place at high pressure and low temperature. The actual separation of the carbon dioxide from the liquid, however, is carried out under low pressure and high temperature, where the level of the liquid needs to be kept as constant as possible.