and H 2 O. We also show column temperature at the exit of the adsorption column as a function of cycle time. The cycle time are shown by vertical lines on the cyclic profile. For VASFON and BETGUE the cyclic profile and process based performance of the CO 2 separation is same irrespective of the crystal size with molecular diffusion or with constant pellet diffusion. Hence, we report only cyclic simulation profile for constant diffusivity. Comparing Figure and Figure , VASFON with higher capacity has longer adsorption step while BETGUE with lower CO 2 capacity has shorter adsorption step. For MOCHIW and EVOMOR due to lower microscopic diffusivity, show cyclic simulation profile changing as a function of crystal size showing separation deteriorating with increasing crystal size. Comparing constant diffusivity cyclic profiles of MOCHIW (Figure and EVOMOR (Figure ), they show similar behavior as of VASFON and BETGUE. However, comparing cyclic profiles for constant diffusivity (Figure ) and variable diffusivity (Figure ) for MOCHIW, shows the cycle becoming shorter with earlier CO 2 breakthough reducing the separation performance with inclusion of the microscopic diffusivity. Similarly poorly performing MOF EVOMOR, cycle becomes even shorter with the inclusion of the diffusivity. The short cycle due to very low diffusivity of CO 2 makes concentration and temperature arbitrary from the process optimization. For EVOMOR with diffusivity considerations (Figure , the CO 2 breakthough is observed very early in shortest adsorption step along with N 2 leading to no selectivity due to very low diffusivity, thereby limiting the possible purity or recovery in cyclic separation process.