Abstract: The C₅/C₆ isomerization unit which used reforming topped oil and aromatics extraction raffinate as raw materials for gasoline blending components were adjusted. The C₇+ components from the bottom of the extractive distillation tower with 13—18 t/h which contain normal alkane were sented to FCC unit. The cyclohexane components from the bottom of the de-hexane tower were sented to the catalytic reforming unit. The results showed that under the condition of dual benzene extraction process, after the operation parameters were optimized and adjusted, the FCC unit increased propylene production by 0.5—1.2 t/h, the catalytic reforming unit increased benzene production by 0.3—0.4 t/h, the RON of the isomerization product increased from 80.4 to 84.6 and the vapor pressure increased from 85.7 kPa to 104.9 kPa, the RON of the gasoline pool increased from 93.82 to 94.39. The energy consumption of the unit reduced from 41.30 kgOE/t(1 kgOE=41.8 MJ) to 21.09 kgOE/t. The goals of reducing oil and increasing chemicals, as well as energy conservation and consumption reduction were achieved.

Key words: isomerization, C₆, C₇, octane number, alkane, propylene