MFI-Type Zeolite Membranes for Pervaporation Separation of Dichlorobenzene Isomers

MFI-type zeolitic membranes were prepared on the porous alpha-A(2)O(3) support to investigate the separation properties of dichlorobenzene isomers. The pervaporation tests were performed with unary and binary isomer mixtures at 333 K. The results indicate that the silicalite membranes, irrespective of being synthesized by the templated or template-free method, are permeable for all dichlorobenzene isomers. The pervaporation fluxes of the pure dichlorobenzene isomers decrease in the order p-DCB > o-DCB > m-DCB. For the binary pervaporation system, the dichlorobenzene fluxes are all less than those with a single component due to the binary interactions between DCB isomers and between the DCB isomer and the zeolite membrane. Comparatively, the template-free MFI-type zeolite exhibits higher selectivity for dichlorobenzene isomers due to less inter-crystalline gaps. The separation factors for p-/o-DCB and p-/m-DCB can reach 16.7 and 22.0, respectively.