Dealkylation in Fluid Catalytic Cracking Condition for Efficient Conversion of Heavy Aromatics to Benzene-Toluene-Xylene.

Based on the characteristics of typical C9 + aromatics in naphtha fractions, the effects of key process parameters and heavy aromatic composition on product distribution of fluid catalytic cracking (FCC) of heavy aromatics (HAs) were investigated. The results show that catalysts with large pore size and strong acid sites are favorable for the conversion of HAs to benzene-toluene-xylene (BTX) at higher reaction temperatures and moderate catalyst-oil ratios (C/O). With a Y zeolite-based catalyst which was hydrothermally pretreated for 4 h, the conversion of Feed 1 at 600 °C and C/O of 10 may reach 64.93%. Meanwhile, the yield and selectivity of BTX are 34.80 and 53.61%, respectively. The proportion of BTX can be adjusted within a certain range. The HAs from different sources show high conversion and good BTX selectivity, which provides strong support for the technological development of HAs to light aromatics in FCC operation.