Abstract: Based on collection and analysis the data of cracked naphtha compositions and induction period, factors affected the induction period are investigated. Results show that the main causes of low induction period of cracked naphtha are the high diene number and low phenol content. Due to the characteristics of hydrotreated residue, high heavy metals content and low crackability, the reaction temperature of RFCC is high and metals deposited on the equilibrium catalyst are heavy, therefore, thermal cracking reactions are enhanced and hydrogen transfer reactions are decreased, which leads to the high content of conjugated diene. Low oxygen content of hydrotreated residue feed leads to the low phenol content of naphtha. However, by optimizing the properties of FCC feedstock, operation conditions and gasoline blending, as well as adding some antioxidant, the induction period of gasoline meets the requirement.

Key words: hydrogenation, residue, catalytic cracking, gasoline, induction period, phenol, diene number