A simulation study for the treatment of Kuwait sour gas by membranes

Sour gas of the west fields of Kuwait is reported to have a concentration of 12 mol% carbon dioxide and 4 mol% hydrogen sulfide along with moistures. The gas is treated at the gathering center using amine and ethylene glycol units. However, the two processes are energy-intensive and work with solvents that necessitate proper disposal. On the other hand, polymeric membranes provide an energy-efficient solution for acid gas removal with gas dehydration in one step. A simulation study by UniSim was performed to determine if the cellulose acetate membranes are sufficient to treat 70,000 m(3) h(−)(1) of gas by producing a stream that meets the pipeline requirements. Results show that the membranes met the standards but the hydrocarbons recovery was extremely low. It was concluded that the sour gas should contain no more than 3.5 mol% of carbon dioxide and 0.15 mol% hydrogen sulfide to attain a hydrocarbons recovery of 97%.