Abstract: A petrochemical enterprise encountered an issue of elevated particulate matter concentration in the flue gas of desulfurization tower of No.3 catalytic cracking unit. Through multi-angle analysis, it was identified that the primary cause of the increased particulate matter concentration at the desulfurization tower outlet was a decline in dust removal efficiency. By adjusting key parameters such as reducing the catalyst inventory in the reaction-regeneration system,lowering the bed level of the first regenerator,increasing the discharge duration of the third-stage cyclone fine powder storage tank, and raising the external drainage flow rate of the desulfurization tower, the particulate matter concentration in the flue gas was stabilized at approximately 20 mg/m³, meeting the relevant regulatory requirements.

Key words: catalytic cracking, flue gas desulfurization, concentration of particulate matter