Kinetics of xylene isomerization over silica‐alumina catalyst

Eleven mixtures of the three isomers of xylene and ethylbenzene were isomerized over a silica‐alumina catalyst in a differential tubular reactor at temperatures from 700° to 900°F. and pressures from 0 to 100 lb./sq. in. gauge. Analysis showed that meta‐xylene isomerizes reversibly to ortho‐ and para‐xylene, but the direct interconversion of ortho‐xylene to meta‐xylene does not occur. Further, it appears that the isomerization reactions are first order and, by the Hougen‐Watson technique, follow a single‐site reaction model.