Natural gas separation has grown to one of the largest scale industrial applications of membrane technology during the past three decades. Introducing membrane technology to the natural gas industry presents a major change in conventional gas processing plants with projected growth specifically for CO2/CH4 separation. The most commonly used commercial membrane material for CO2 removal from natural gas is based on cellulose acetate (CA) which has pure-gas selectivity of about 32-35 but under high-pressure, mixed-gas conditions, the CO2/CH4 selectivity often drops to less than 15 coupled with moderate CO2 permeability. Here, I discuss the effect of hydroxyl functionalization on the m-phenylene diamine moiety of 6FDA- and triptycene dianhydrides-based polyimides for gas separation applications.
The dihydroxyl-containing polyimide showed good plasticization resistance and maintained high mixed-gas selectivity when tested at a typical CO2 natural gas wellhead CO2 partial pressure of 10 atm. Functionalization with hydroxyl groups may thus be a promising strategy towards attaining highly selective polyimides for economical membrane-based natural gas sweetening.
Level 0, between bld. 4 and 5
11:30 - 12:00