Amine-functionalized (Al) MIL-53/VTEC™ mixed-matrix membranes for H2/CO2 mixture separations at high pressure and high temperature

Abstract VTEC™ PI-1388 and 20 wt% (Al) NH 2 -MIL-53/VTEC™ PI-1388 mixed-matrix membranes (MMMs) with different thicknesses were tested for gas permeation of H 2 and CO 2 from 5 to 30 bar and from 35 to 300 °C. 50/50 H 2 /CO 2 mixtures were also tested at 30 bar and 250 °C with stage cuts that ranged from 0.05 to 1. Gas permeation data show that the affinity of (Al) NH 2 -MIL-53 for VTEC™ PI-1388 is strong enough to perform gas separations under these conditions. At 30 bar and at temperatures above 200 °C, the performance of the MMMs for H 2 /CO 2 separation improved significantly with increasing temperature. Specifically, the H 2 permeability of the MMM at 300 °C increased by 70% with respect to that of VTEC™ PI-1388 (VTEC™ PI-1388: H 2 = 85 Barrer, H 2 /CO 2 = 4.0; MMM: H 2 = 144 Barrer, H 2 /CO 2 = 5.8). Gas mixture separations using VTEC™ PI-1388 and the MMM depended on the stage cut and reached a maximum H 2 /CO 2 separation of 7.2 for VTEC™ PI-1388 and 7.5 for the MMM at a stage cut of 0.05.