Abstract: A fixed fluidized bed reactor was used to study the effect of hydrocarbon components of catalytic cracking feedstock on the production of light olefins from the feedstock of HVGO-1, HVGO-2, HVGO-3, HVGO-3 light fraction and HVGO-3 heavy fraction. Compared with HVGO-1 with the similar density and hydrogen content, the higher cycloalkane content and lower aromatic content of HVGO-2 resulted in higher light olefins yield, and the same reaction rules were obtained for HVGO-3, HVGO-3 light fraction and HVGO-3 heavy fraction. Paraffins, naphthenes and monocyclic aromatics are the dominant components in the production of light olefins and gasoline. Among them, paraffins and naphthenes are the high value components in the production of light olefins, while alkylbenzenes are the high potential components in the production of gasoline and light aromatics (BTX). Under the same reaction conditions, the high content of cycloalkylbenzene in the HVGO-3 light fraction leads to the hydrogen transfer side reaction of light olefin precursors and light olefins, which affects the formation of light olefins. The hydrogenation pretreatment of FCC feedstock can improve the yield of light olefins by controlling the hydrogenation depth and realizing the conversion of polycyclic aromatic hydrocarbons to naphthenes, avoiding the formation of cycloalkylbenzene due to the lack of hydrogenation depth.

Key words: hydrogenated VGO, catalytic cracking, light olefins