A process for recovering CO.sub.2 from a feed gas stream comprises treating the feed gas stream with a regenerated absorbent comprising at least one tertiary amine absorbent having a pK.sub.a for the amino function of from about 6.5 to about 9 in the presence of an oxidation inhibitor to obtain a CO.sub.2 rich stream and subsequently treating the CO.sub.2 rich stream to obtain the regenerated absorbent and a CO.sub.2 rich product stream. The feed gas stream may also include SO.sub.2 and/or NO.sub.x.