Method for treating by-product SO2 in sucralose production

The invention relates to a method for treating a by-product SO2 in sucralose production, which is characterized in that sucralose tail gas sequentially passes through a first-stage water washing tower, a second-stage water washing tower and a third-stage water washing tower to wash and absorb hydrogen chloride in the tail gas, and when the concentration of hydrochloric acid in the first-stage water washing tower reaches 32-35%, the hydrochloric acid is collected into a finished product hydrochloric acid tank; (2) the unabsorbed tail gas enters a sulfuric acid drying tower to remove moisture, the dried tail gas is pressurized to 0.4-0.5 MPa through a compressor and then sequentially enters a first-stage rectifying tower and a second-stage rectifying tower to be rectified, the bottom temperature of the first-stage rectifying tower is controlled to be 45-55 DEG C, the bottom pressure of the first-stage rectifying tower is controlled to be 0.4-0.45 MPa, the bottom temperature of the second-stage rectifying tower