Application
Hydrogen is a renewable energy carrier primarily produced through steam reforming of fossil resources, which also generates CO₂ as a byproduct. Membrane separation technology can capture CO₂ while producing pure H₂ efficiently. High-temperature carbon-capture operations require thermally stable materials, and polybenzimidazoles are suitable due to their stability at temperatures over 150°C. However, common polybenzimidazole polymers like m-PBI have limited solubility, posing challenges in industrial applications.

Key Parameters and Requirements
Researchers funded by the U.S. Department of Energy studied polybenzimidazoles based on TADPS monomers, which are stable above 400°C. The permeabilities of various gases were measured using a constant-volume, variable-pressure method. Master Bond EP46HT-2 epoxy was used to mount sample films due to its high temperature and chemical resistance. The epoxy was cured at 140°C and post-cured at 180°C, with samples degassed at 190°C.

Results
The study found that gas permeability increased with temperature, but CO₂ activation energy decreased. Selectivity among CO₂/N₂, CO₂/CH4, and N₂/CH4 decreased with temperature, while H₂/CO₂ selectivity increased. Master Bond EP46HT-2's service temperature range from -73°C to +260°C and decomposition temperature over 350°C make it ideal for temperature-dependent research. Its 100% reactive nature ensures no interference with gas readings. The results suggest advancements in H₂-selective membranes and potential improvements in PBI materials for gas separations.

References
1. Bitter, J.H., & Tashvigh, A.A. (2022). Recent Advances in Polybenzimidazole Membranes for Hydrogen Purification. Ind. Eng. Chem. Res.
2. Merkel, T.C., Zhou, M., et al. (2012). Carbon dioxide capture with membranes at an IGCC power plant. Journal of Membrane Science.
3. Lyoo, W.S., Choi, J.H., et al. (2000). Preparation of organo-soluble poly[(2,2’-m-phenylene)-5,5’-bibenzimidazole]. Journal of Applied Polymer Science.
4. Stevens, K.A., Moon, J.D., et al. (2020). Influence of temperature on gas transport properties of TADPS-based polybenzimidazoles. Journal of Membrane Science.