LAUSR

Abstract This work evaluates the potential of a mixed matrix membrane synthesized with 1-ethyl-3-methylimmidazolium-ethylsulphate [EMIM][EtSO4] a common ionic liquid (IL) blended with poly (ether-block-amide) (PEBA) elastomer to separate either hydrogen sulphide (H2S) or carbon dioxide (CO2) or both acid gasses (H2S and CO2) from its streams. Layer-by-layer deposition method was used to synthesize the defect-free blended membrane. The prepared membranes were characterized by field emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) for physical and thermal properties. Several experiments were conducted by varying pressure and ionic liquid concentration at normal temperature for pure gases (H2S/CO2/CH4/Air). The presence of ionic liquid (5 wt%) shows higher H2S permeability of 540 barrer and a comparatively low CO2 permeability of 55 barrer at pressure of 7 kg/cm2 through the blended membrane due to higher H2S solubility (1.5 times more than CO2) in the same IL. The trend of permeability for different single gases was observed in the pattern following: H2S > CO2>Air > CH4. Ideal selectivity was 66.0 for H2S/CH4 and 24.0 for H2S/Air which is much higher than those for CO2 binary mixture such as CO2/CH4 (4.6) and CO2/Air (2.4). The addition of ionic liquid in the membrane matrix enhances the permeability of acid gases compared to pure PEBA membrane. Robeson’s diagram also shows the promising trends for the experimental points either crossing the upper bound line or getting nearer which highlight the pivotal role of IL in blended membrane.