Catalytic cracking of a mixture of dodecane and 1,3,5 tri-isopropyl-benzene over USY and ZSM-5 zeolites based catalysts

摘要

The reaction of dodecane (C12) and l,3,5.tri-isopropyl-Benzene (TIPB) was experimentally investigated over catalyst SB (based on USY zeolite) and GKF-3 (based on ZSM5 zeolites).Series of experiments with pure and 50-50 weight percent mixtures of C12 and TIPB were conducted.The reaction conditions were adjusted to simulate a commercial FCC unit at 450 deg C,cat/oil ratio of 5,pressure of 1-1.5 bar,and reaction times of 3-15 sec.GKF-3 was observed to give higher C12 conversion compared to SB.On the contrary,the kinetic of TIPB showed a complicated behavior due to the mutual effects of zeolite acidity and pore size.The conversion of pure C12 on SB was observed to be lower than the conversion of TIPB while the opposite was true on GKF-3.This behaviour could be attributed to the higher activation energy of paraffin catalytic cracking compared to alkyl-aromatic dcalkylation.While,the conversion of C12 was not affected by the presence of TIPB in both catalysts a huge drop in the conversion of TIPB was observed in the presence of C12 over both catalysts.This indicates that the diffusion of TIPB molecules is the rate determining step.