Investigation of [H.sub.2]S and C[O.sub.2] Removal from Gas Streams Using Hollow Fiber Membrane Gas-liquid Contactors

Chemical absorption of [H.sub.2]S and C[O.sub.2] from C[H.sub.4] was carried out in a polypropylene porous asymmetric hollow fiber membrane contactor (HFMC). A 0.5 mol [L.sup.-1] aqueous solution of methyldiethanolamine (MDEA) was used as chemical absorbent solution. Effects of gas flow rate, liquid flow rate, [H.sub.2]S concentration and C[O.sub.2] concentration on the [H.sub.2]S outlet concentrations and C[O.sub.2] removal percentage were investigated.The results showed that the removal of [H.sub.2]S with aqueous solution of MDEA was very high and indicated almost total removal of [H.sub.2]S. Experimental results also indicated that the membrane contactor was very efficient in the removal of trace [H.sub.2]S at high gas/ liquid flow ratio. The removal of [H.sub.2]S was almost complete with a recovery of more than 96 %. Using feed gas mixtures containing 5000 ppm [H.sub.2]S with C[O.sub.2] concentrations in the range of 4-12 vol.%, the outlet [H.sub.2]S concentration of less than 1.0 ppm was attained with less than 4.0 vol.% of C[O.sub.2] permeated and absorbed.Key words: hollow-fiber membrane contactor, MDEA, hydrogen sulphide, carbon dioxide