Transformation of Cycloparaffin over Zeolite-Supported Metal Catalyst for Improving the Octane Number of Gasoline

Abstract

In order to improve the octane number of gasoline, Ni/HZSM-5 and NiMo/HZSM-5 catalysts were prepared by impregnation method, and their activities for hydrocracking, hydroisomerization, and aromatization were investigated by the transformation of cylcohexane. The experimental results show that the conversion of cyclohexane is affected greatly by the reaction temperature. The production of methyl-cyclopentane is the result of the hydroisomerization of cyclohexane. The olefin distribution reveals that the hydrocracking reaction of cyclohexane over acidic zeolite catalyst probably obeys the dimolecular mechanism and the C₅ and C₇ olefins come from the cracking of the dimer of cyclohexane. The activities of the presulfided Ni/HZSM-5 and NiMo/HZSM-5 catalyst for the transformation of cyclohexane were evaluated and the product selectivities for two presulfided catalysts are similar to those obtained over reduced Ni/HZSM-5 catalyst.

Keywords:

• cracked naphtha
• FCC
• sulfur
• aromatization
• ZSM-5
• hydrodesulfurization

ACKNOWLEDGMENT

Financial support from PetroChina Corporation Limited is greatly appreciated.