Abstract: Due to the high content of sulfur in tail gas from caustic regeneration unit of LPG sweetening unit，the concentration of SO₂ in the flue gas of heating furnace will increase greatly when it is sent directly to the heating furnace of atmospheric and vacuum distillation unit. The results of off-line simulated absorption experiments showed that FCC diesel had a good absorption effect on sulfur compounds in the regeneration tail gas. According to the test results, the flue gas desulfurization system was reformed, and the SO₂ concentration in the flue gas discharged from the heating furnace was greatly reduced, which could meet the relevant national and local emission standards.

Key words: Regeneration tail gas, Diesel absorption, Heating furnace, SO₂