Abstract: In order to explore the method of increasing the flexibility of heavy aromatics cracking technology, the distribution of BTX during the cracking reaction of heavy aromatics was studied. The results indicated that the proportions of benzene, toluene and xylene were affected by the pore structure of catalysts, reaction conditions and feed composition. ZSM-5zeolite based catalyst tended to produce more benzene and toluene, while Y zeolite based catalyst tended to more xylene. The reaction conditions had a great influence on the proportions of benzene, toluene and xylene in BTX, and the proportions of toluene and benzene can be increased by increasing the reaction temperature or catalyst activity. The composition of feeds affected the proportion of benzene, toluene and xylene in BTX product. When the feed contained a higher proportion of trimethyl-benzene, the xylene proportion in BTX product was higher, and the higher the methyl ethylbenzene in the feed was, the higher the toluene in BTX was. The pore structure of catalysts also affected the distribution of xylene isomers, but the reaction conditions and the composition of feeds had little effect on the proportions of xylene isomers.

Key words: heavy aromatics, conversion to light fraction, catalytic cracking, BTX, xylene isomer