Diffusion of CH4 and CO2 in MFI, CHA and DDR zeolites

Making CH4 and CO2 diffuse across a zeolite membrane results in separation of the two components. The separation is due to subtle differences in the dimensions of the two molecules. Three different zeolites (MFI, CHA, DDR) have been investigated with respect to their diffusion characteristics. The results presented in this work show that CHA (shown in the snapshot on the right) and DDR, both consisting of cages separated by narrow windows, have considerable potential for use in industry.