Abstract: Based on the analysis of hydrocarbon composition and heteroatom distribution in light cycle oil(LCO) from catalytic cracking unit, the different processing technology routes were proposed for different fractions of LCO. The analysis results show that aniline and indole nitrides in LCO are mainly distributed in the light and middle (<290 ℃)distillation section, while carbazole is mainly concentrated in heavy distillation section (>320 ℃). There is almost no thiophene sulfide in LCO, and the benzothiophene sulfide appears in the LCO fraction with initial boiling point over 290 ℃. Moreover almost all the sulfides in the heavy fraction belong to dibenzothiophene sulfide. The hydrotreating process results show that the full fraction of LCO requires severe conditions to achieve the increase of cetane number by hydrogenation reaction. The aromatics hydrogenation saturation in the middle fraction of LCO (240-320 ℃) under mild conditions could result in the 13.9 increase in cetane number of the product which could serve as the diesel blending components for China VI standard. The light fraction of LCO(<240 ℃) is suitable for catalytic cracking process to produce high-octane gasoline blending components.

Key words: light cycle oil, hydrotreating, cetane number, dibenzothiophene