Modeling and simulation of the efficient separation of methane/nitrogen mixtures with [Ni3(HCOO)6] MOF by PSA

In this work, [Ni-3(HCOO)(6)] metal-organic framework (MOF) has been synthesized and shaped into pellets using polyvinyl alcohol as binder. The adsorption equilibrium isotherms of methane and nitrogen onto the pellets have been determined between 0 and 120 kPa at 28, 40 and 65 degrees C. A model has been developed to describe the column adsorption dynamics of methane/nitrogen mixtures in a bed of [Ni-3(HCOO)(6)] pellets. The mass transfer parameters of methane and nitrogen have been determined from breakthrough experiments. The model has been validated with experimental breakthrough curves obtained with methane/nitrogen mixtures. A dual PSA process has been designed by using the measured equilibrium and kinetic parameters in a PSA simulation tool (PSASIM (R)). It was evidenced that the process can recover methane from a 50/50% methane/nitrogen mixture at 1 bar and 298 K with a purity of 96%, obtaining a residual effluent with a methane concentration of 320 ppmv (methane recovery above 99.9%), a productivity of 1.7.10(-4) mol kg(-1) s(-1) and a thermal energy consumption of 4MJ kg(-1).