Formosa Petrochemical Corp (FPCC) reduced the mass flow rate to regeneration and increased the absorption and regeneration capacity at its amine treating regeneration system after replacing diethanolamine (DEA) with methyldiethanolamine (MDEA)/DEA blends on line. The required MDEA/DEA blending formulation was at a ratio 1.647, which was based upon the CO2 specification of the downstream residue catalytic cracking unit. Utilizing the highly efficient MDEA/DEA blends reduced the amine circulation rate and mass flow rate to regeneration by around 18%. This decrease resulted in steam consumption being reduced by 24% and the gas processing capacity being increased by 12% by improving the efficiency and introducing new expansion absorbers on line. Details of the study are presented.