High Temperature Polybenzimidazole Hollow Fiber Membranes for Hydrogen Separation and Carbon Dioxide Capture from Synthesis Gas

Sustainable reliance on hydrocarbon feedstocks for energy generation requires CO2 separation technology development for energy efficient carbon capture from industrial mixed gas streams. High temperature H2 selective glassy polymer membranes are an attractive option for energy efficient H2/CO2 separations in advanced power production schemes with integrated carbon capture. They enable high overall process efficiencies by providing energy efficient CO2 separations at process relevant operating conditions and correspondingly, minimized parasitic energy losses. Polybenzimidazole (PBI)-based materials have demonstrated commercially attractive H2/CO2 separation characteristics and exceptional tolerance to hydrocarbon fuel derived synthesis (syngas) gas operating conditions and chemical environments. To realize a commercially attractive carbon capture technology based on these PBI materials, development of high performance, robust PBI hollow fiber membranes (HFMs) is required. In this work, we discuss outcomes of our recent efforts to demonstrate and optimize the fabrication and performance of PBI HFMs for use in pre-combustion carbon capture schemes. These efforts have resulted in PBI HFMs with commercially attractive fabrication protocols, defect minimized structures, and commercially attractive permselectivity characteristics at IGCC syngas process relevant conditions. The H2/CO2 separation performance of these PBI HFMs presented here in realistic process conditions is greater than that of any other polymeric system reported to-date.