A process for absorbing carbon dioxide from a gas stream containing carbon dioxide, including the steps of contacting the gas stream with an aqueous composition including a substituted heteroaromatic compound having a six-membered heteroaromatic ring with from 1 to 3 nitrogen atoms in the heteroaromatic ring and at least one substituent wherein at least one of the substituents is of formula —R1NH2 wherein R1 is selected from C1 to C6 alkylene and ethers of formula —R2—O—R3— wherein R2 and R3 are C1 to C3 alkylene.