Abstract: Systems and methods for preventing formation of carbonyl sulfide in the production of sweet gas using an amine-lean aqueous solution and metal oxide adsorbent material. In embodiments, a method may include producing, via an amine absorption column supplied with a raw gas stream that includes fractions of hydrogen sulfide (H2S), carbon dioxide (CO2), and carbon monoxide (CO), (1) a sweet gas stream that includes the fractions of the CO and (2) an amine-rich aqueous solution that includes the H2S and CO2. The method may include heating the amine-rich aqueous solution to produce a heated amine-rich aqueous solution. The method may include producing, via an amine regenerator supplied with the heated amine-rich aqueous solution (1) an acid gas stream that includes the H2S and CO2 and (2) an amine-lean aqueous solution. The method may include producing, via adsorption in a metal oxide adsorbent vessel, an effluent stream that includes the CO2.