Method for absorbing CO2 from a gas mixture

Abstract

In a method of absorbing CO2 from a gas mixture the use of an absorption medium comprising water and at least one amine of formula (I) where R1 is a —(CH2)n—(XCH2CH2)m—Y—R3 radical where R3=hydrogen or an alkyl radical having from 1 to 6 carbon atoms, X and Y are each, independently of one another, NR3, oxygen, SO or SO2, where in the case of Y═SO and in the case of Y═SO2, R3 is not hydrogen, and Y—R3 can be an N-morpholinyl radical or an N-piperazyl radical, n=2 to 4, m=0 to 4 and R2 is hydrogen, an alkyl radical having from 1 to 6 carbon atoms or a radical R1, where m is not 0 when R2 is not a radical R1, Y═NR3 and Y—R3 is not an N-morpholinyl radical and not an N-piperazyl radical, makes it possible to avoid precipitation of a solid during the absorption of CO2 and a separation into two liquid phases during the regeneration of the absorption medium.

Dependencies are inferred from the claim text.