INFLUENCE OF THE SILICA MODULE OF PENTASILS ON DIFFUSION AND KINETICSPARAMETERS IN THE REACTION OF XYLENE ISOMERIZATION

The influence of the acidity of pentasils on the values of both kineti c and diffusion parameters of xylene isomerization is studied. True ra te constants and activation energies for xylene isomerization, adsorpt ion coefficients and heats of adsorption of active sites, diffusivitie s and activation energies for diffusion of o- and p-xylenes are measur ed for pentasils with the silica module (SiO2/Al2O3) values ranging fr om 37 to 111. The rise in the module value leads to a decrease of cata lytic activity. A noticeable fall in both activation energies and adso rption heats is observed only upon the module rise from 55 to 111. Dif fusivities of xylenes decrease upon increasing of the module, but the change in diffusion activation energies is insignificant.