Upscaling polyPOSS-imide membranes for high temperature H2 upgrading

In the present work, the potential of polyPOSS-imide membranes designed for the purification of H2 from a coke gas (utilized in the steelmaking industry) is investigated. Aiming at upscaling the membrane fabrication, tubular single-channel and multi-channel membranes were prepared, using polyhedral oligomeric silsesquioxane (POSS) nanostructures and 6FDA as reactive precursors. The gas separation performance has been investigated by means of single gas and quaternary (H2, CH4, CO2, N2) mixtures, the latter used to simulate the conditions expected at the membrane module inlet in the process of upgrading H2 from a coke oven gas. Preliminary results obtained on tubular membranes showed that the fabricated membranes can achieve high H2 permeance (>2000 GPU), displaying also suitable selectivity towards CO2, N2 and CH4. The selectivity of these upscaled tubular membrane samples meets the performance of those previously obtained for the disc-shaped lab-scale membranes. These results revealed the promising potential in the upscaling of polyPOSS-imide membranes fabricated via interfacial polymerization on ceramic porous supports for H2 upgrading.