Carbon dioxide capture from reforming gases using acetic acid-mixed chemical absorbents

Carbon dioxide (CO₂) is a major problem in the production of natural gas as it may contribute to the operational problems such as foaming, corrosion, high solution viscosity, and fouling, thereby decreasing the plant life. The presence of acid gas in natural gas reforming may also result in the increase of transported gas volume and the decrease of heating value. Absorption using aqueous solutions of alkanolamines has been a preferred approach in current industry for CO₂ removal. Concentration of ammonia and DEA affects the CO₂ removal; increasing the absorbents concentration increases the CO₂ removal. On molar basis, DEA shows a greater CO₂ absorption than ammonia. Acetic acid-mixed absorbents display a lower CO₂ removal than the nonmixed ones. Decrease in solubility due to the decrease in solution pH has resulted in a lower CO₂ absorption by acetic acid-mixed absorbents. Liquid flow rate offers only small influence on the absorption of CO₂, while decreasing the gas flow rate increases the CO₂ removal. On the operational point of view, blend of ammonia and DEA absorbent would be beneficial for CO₂ removal from reforming gases as it could partly solve the problems associated with regeneration and corrosion.