Abstract
Various alumina-deficient H-mordenites are prepared and tested as catalysts for the hydroconversion of heavy alkylate (b.r., 320-476°C) and its fractions (I, b.r. 320-400°C and II, b.r. 400-476°C). These include mordenites having SiO2/Al2O3 ratios of 20, 40, 60, 90 and 125 designated HM(AD)20, HM(AD)40, HM(AD)60, HA(AD)90 and HA(AD)125, respectively. Upon dealumination, the total BTX contents of cut I of the reaction products increase considerably reaching values of 42.4% for HM(AD)20 and 40.0% for HM(AD)40. It has been indicated that dealumination favours the disproportionation and transalkylation reactions resulting in higher yields of C8 aromatics. Fraction I yields higher percentages of xylenes at the expense of benzene while, on the contrary, higher yields of benzene and lower yields of xylenes are obtained with fraction II.