Method for recycling tail gas of sulfonyl chloride chlorination in Cmoba synthesis

The invention relates to a method for recycling tail gas of sulfonyl chloride chlorination in Cmoba synthesis, and belongs to the tail gas absorption and treatment in the chemical field. The method is characterized by comprising the following steps: gaining sulfur dioxide and hydrogen chloride which are generated in the reaction; carrying out two-stage absorption on the hydrogen chloride by water to obtain the hydrochloric acid containing little sulfur dioxide, wherein the hydrochloric acid containing little sulfur dioxide is utilized in the alkylation step of the Cmoba preparation process; carrying out two-stage absorption on the rest sulfur dioxide through ammonia water to prepare the mixed solution of ammonium hydrogen sulfite and ammonium sulfite; and concentrating the obtained ammonium salt solution which is directly used as a reducing agent. By adopting the method, the gases, namely, hydrogen chloride and the sulfur dioxide, produced in the Cmoba chlorination process can be effectively recycled, so that