In the process of repeated benzene absorption and debenzenization of washing oil, due to multiple heating and polymerization of hydrogen sulfide in gas and unsaturated matter dissolved in washing oil, the weight and viscosity of washing oil increase, the boiling point increases, and the absorption efficiency decreases. In order to ensure the quality of circulating washing oil, 1-1.5% of circulating oil is extracted for continuous regeneration

Direct steam is passed into the regenerator to make its low boiling point residual (300C part) continuous distillation, while the high boiling point distillate is regularly (or continuously) discharged from the bottom of the regenerator, so that the oil washing regeneration requires that the oil content of the regenerator residue (300C) is <30%.