Sulfur Removal from Gasoline by Pervaporation

Sulfur present in gasoline results in air pollution by SOx emissions. With the mixtures of thiophene/n-hexane making up the model gasoline, PDMS/PA composite membrane was used for sulfur removal from gasoline by pervaporation. Effects of sulfur content (0.3-0.6 wt.%), feed temperature (30-50 ºC), permeate pressure (23-100 mmHg) and feed flow rate (30-90 L/h) were investigated on pervaporation separation of n-hexane/thiophene binary mixtures. Douglas design was used to research the effects of operating parameters on total fluxes. Experimental results indicated that sulfur content and feed flow rate have negligible effects on total flux in comparison with feed temperature and permeate pressure. Increasing feed temperature, sulfur content, feed flow rate and decreasing permeate pressure, increase total flux. According to significance of feed temperature and permeate pressure, effects of these investigated on thiophene enrichment factors. Thiophene enrichment factor increased with decreasing feed temperature and permeate pressure. The highest enrichment factor of thiophene was obtained to be 1.5 at a feed temperature of 30 ºC and a permeate pressure of 23 mmHg.