Influence of zeolite structure on the performance of heavy reformate transalkylation catalysts

Conversion of ethylbenzene (EB) and commercial heavy reformate has been studied on different acid zeolite catalysts. The studied zeolites included topologies with channel systems containing 10 MR, 12 MR and 10+12 MR, namely ZSM-5, IM-5, mordenite, mazzite, Beta, NU-87 and ITQ-23. It has been found that zeolite structure has a direct influence in the ethyl dealkylation and transalkylation activity, increasing the dealkylation activity and selectivity when decreasing the zeolite pore volume. Zeolites NU-87 and ITQ-23 with 10×12 MR pores present an intermediate behavior from that of 10 and 12 MR pore zeolites. It has been also observed that ethylbenzene undergoes different bimolecular reactions involving for each reaction different biphenylic transition states.