Effects of Benzene on Toluene Disproportionation and Transalkylation

The effects of benzene content in feedstocks on toluene disproportionation and C 9 aromatics transalkylation were studied in detail.With increasing benzene content in feedstock,toluene disproportionation was obviously restrained.Simultaneously,transalkylation reaction between benzene and C 9 aromatics took place which could increase conversion of C 9 aromatics and selectivity of C 8 aromatics.Total conversion of toluene and C 9 aromatics would decrease with increasing benzene in feedstock.Higher reaction temperature could keep original total conversion when benzene was added to feedstock.With increasing benzene content in feedstock, quantity of benzene converted exceeded that of benzene yielded,and moreover,benzene became a reactant instead of a product.Thus,disproportionation of C 9 aromatics was restrained so that selectivity of C + 10 aromatics declined from 12% to -8%.These effects facilitate the disproportionation unit to obtain more C 8 aromatics.