Synthesize and characterization of polysulfone membrane for the separation of hydrogen sulfide from natural gas

The existence of Hydrogen Sulfide in natural gas (N.G) can lead to corrosion in equipment, global warming and so on. So, the separation of Hydrogen Sulfide from N.G is essential. In this study, the Polysulfone (PS) membrane was synthesized with Dimethylacetamide (DMAC) and Dimethylformamide (DMF) as solvent. The SEM (scanning electronic microscopy) images were used to compare prepared membranes by DMF and DMAC. An experimental setup was established and the effect of solvents, PS concentration, temperature and pressure were explored on the separation of H2S from N.G. The best temperature was achieved at 25 degrees C. The results showed that the DMAC solvent was more appropriate than DMF and the amount of selectivity of this kind of membrane was reduced with an increase in temperature and pressure. In M3 membranes (20% of PS, DMAC solvent), which was the best membrane, the permeated amount was increased from 11800 to 490000 Barrer with an increase in pressure from 2.5 to 20 Barg, still the selectivity ratio of H2S to N.G was increased with increase in pressure from 2.5 to 5 Barg at first and then reduced with enhance in pressure until 20 Barg. The maximum selectivity ratio of H2S to N.G was 1.56 for M3 membranes at 25 degrees C and 5 barg, at this condition, the permeated amount of H2S was 119000 Barrer.