Method and device for separating acid gases from a gas mixture

摘要

The invention is directed to a method for separating acid gases from a gas mixture in which the gas mixture is contacted with an absorption medium which comprises water and at least one amine and has a phase-separation temperature in the range from 0 to 130° C. In addition, the invention is directed to a device which can be used for carrying out this method.

主权项

1. A method for separating acid gases from a gas mixture, said method comprising:
a) absorbing acid gases by contacting the gas mixture with an absorption medium comprising water and at least one amine to obtain a loaded absorption medium, wherein absorption takes place in an absorber and the absorption medium:
i) shows phase separation into two liquid phases upon heating above a phase-separation temperature in the range of 0 to 130° C.;ii) comprises at least one amine of formula (I): wherein R1 is hydrogen and R2 is an alkyl radical having 1to 6 carbon atoms; b) desorbing acid gases from the loaded absorption medium by stripping the loaded absorption medium with steam in a desorption column, wherein desorption is carried out at a temperature at which a phase separation into a water-rich liquid phase and a water-poor liquid phase occurs in the desorption column; c) separating the water-rich liquid phase and water-poor liquid phase from one another; d) feeding the water-rich liquid phase to an evaporator in which steam is generated with which acid gases are stripped in the desorption column; and e) returning the water-poor liquid phase and water-rich liquid phase to the absorber as absorption medium.