In OSMAHRD, methane loss is a significant contributor to EAOC. To reduce this cost, TSMAHRD is employed; changes in the flowsheet are as follow (Fig. 3). (1) Permeate stream from the first membrane stage is recompressed and sent to the second stage after cooling. (2) Permeate stream of second stage is concentrated with acid components (CO2and H2S) and is discharged from the system. (3) Retentate stream of the second stage contains some methane, and so it is recycled and mixed with the inlet NG in a mixer.