Elevated Temperature Steam and Sulfur Tolerance of H2 Selective Polybenzimidazole Hollow Fiber Membranes

摘要

H2 selective glassy polymer membranes are an attractive option for energy efficient H2/CO2 separations in advanced power, fuels and chemicals production schemes with integrated carbon capture. The high H2 partial pressure in synthesis (syn) gas post water-gas shift reactor provides the necessary driving force for energy efficient membrane separation. Moreover, the permselectivity characteristics are improved at elevated temperatures due to an activated diffusion controlled, molecular sieving gas transport mechanism. However, syngas impurities including steam and H2S demand membrane materials with high thermo-chemical tolerance. Our previous studies have demonstrated the unique thermo-chemical tolerance and H2 perm-selective characteristics of polybenzimidazole (PBI) based materials for syngas separations. PBI has commercially attractive H2/CO2 selectivity, exceptional thermal stability (Tg > 400 °C) and exceptional tolerance to steam and H2S.