Limitations and high pressure behavior of MOF-5 for CO capture

Porous network structures (e.g. metal-organic frameworks, MOFs) show considerable potential in dethroning monoethanol amine (MEA) from being the dominant scrubber for CO at the fossil-fuel-burning power generators. In contrast to their promise, structural stability and high-pressure behavior of MOFs are not well documented. We herein report moisture stability, mechanical properties and high-pressure compression on a model MOF structure, MOF-5. Our results show that MOF-5 can endure all tested pressures (0-225 bar) without losing its structural integrity, however, its moist air stability points at a 3.5 hour safety window (at 21.6°C and 49% humidity) for an efficient CO capture. Isosteric heats of CO adsorption at high pressures show moderate interaction energy between CO molecules and the MOF-5 sorbent, which combined with the large sorption ability of MOF-5 in the studied pressure-temperature ranges show the viability of this sorbent for CO capturing purposes. The combination of the physicochemical methods we used suggests a generalized analytical standard for measuring viability in CO capture operations. © the Owner Societies 2013.