Transalkylation of Toluene with 1,2,4-Trimethylbenzene over Large Pore Zeolites

Using industrially relevant operating parameters, the transalkylation of 1,2,4-trimethylbenzene (TMB) with toluene was studied. The effect of acidity and structure, increased reaction pressure, and very low levels of Pt impregnation have been investigated over both H-form and Pt-loaded zeolites: Beta, MOR, and Y. A fixed bed reactor was used at WHSV of 5 h–1, 400 °C, and a 50:50 wt % toluene:TMB ratio with the order of activity after 50 h TOS of Y > Beta ≫ MOR at 1 bar. At elevated pressure (10 bar), all catalysts showed better performance with significant improvement in MOR as pore blockage reduced and the order of activity was Beta > MOR > Y. Incorporation of Pt (0.08 wt %) further improved the activity of all catalysts with the highest conversion after 50 h TOS over Beta (62 wt %) where Beta and MOR yielded similar levels of xylenes (40 wt %). All catalysts were further optimized for activity while maintaining the desired stability and highest xylenes yield.