Abstract: Catalytic distillation technology is successfully applied in FCC heavy gasoline hydrodesulfurization unit of Sinochem Quanzhou Petrochemical Co.，Ltd. The calibration results show that for high sulfur feed，the sulfur content of FCC heavy gasoline is lowered from 599.0-981.0 μg/g to 3.8-7.0 μg/g and RON loss is only 2.1-2.9；and for the low sulfur feed，the sulfur content is reduced from 176.0 μg/g to1.3 μg/g and RON loss is about 0.5. At the initial stage of running，larger level fluctuation in the CDHDS column and the serious liquid entrainment of interstage knockout drum of circulating hydrogen compressor were observed. Measures，such as improving the level control scheme for CDHDS column，increasing the inlet pressure of the recycle hydrogen compressor，and adding the level regulating valve at bottom of the knockout-drum were adopted, resulting in improvement of the unit operation.

Key words: FCC heavy gasoline, catalytic distillation, hydrodesulfurization, research octane number