Separation of CO2/CH4 and CH4/N2 mixtures using MOF-5 and Cu3(BTC)2

In this paper we used MOP-5 and Cu-3(BTC)(2) to separate CO2/CH4 and CH4/N-2 mixtures under dynamic conditions. Both materials were synthesized and pelletized, thus allowing for a meaningful characterization in view of process scale-up. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). By performing breakthrough experiments, we found that Cu-3(BTC)(2) separated CO2/CH4 slightly better than MOF-5. Because the crystal structure of Cu-3(BTC)(2) includes unsaturated accessible metal sites formed via dehydration, it predominantly interacted with CO2 molecules and more easily captured them. Conversely, MOF-5 with a suitable pore size separated CH4/N-2 more efficiently in our breakthrough test.