Abstract: In order to produce high octane gasoline in accordance with the national VIB gasoline standard, the solid superacid C₅/C₆ isomerization catalyst developed by SINOPEC Research Institute of Petroleum Processing was used in a refinery and its supporting process technology was also adopted. The idle 190 kt/a semi-regeneration catalytic reforming unit was converted into a C₅/C₆ isomerization unit for the processing of reformer topping oil rich in benzene and heptane. The industrial practice results showed that it was feasible to transform the semi-regeneration reforming unit into the isomerization unit of solid superacid C₅/C₆. Under the condition of qualified water content, catalyst RISO-C had excellent isomerization activity and stability even when the benzene and C₇ mass fraction of C₅/C₆ isomerization feedstock were 4%-8% and 10%-18%, respectively. At the same time, it had good benzene hydrogenation activity, which increased the research octane number (RON) of isomerized products by 4-8 units, reaching 82 or above, and the benzene content was below 0.8%. Combining the C₅/C₆ isomerization unit of solid superacid with C₇+ reforming unit, the benzene content of reformer gasoline could be reduced, and the high octane number gasoline conforming to the national VIB gasoline standard could be produced, which had remarkable economic and social benefits.

Key words: C₅/C₆ alkanes, isomerization, RISO-C, solid superacid catalyst, octane number