Recovery method and recovery device for sulfur dioxide in sucralose chlorination reaction

Abstract

The invention relates to a recovery method for sulfur dioxide in sucralose chlorination reaction. The method includes steps: 1, adding concentrated sulfuric acid into a drying tower, removing moisturefrom tail gas of a gas-liquid separator, and allowing dried sulfur dioxide and trichloroethane tail gas to enter a primary condenser; 2, allowing residual tail gas and condensate flowing through theprimary condenser to enter a trichloroethane separation tank, allowing sulfur dioxide and trichloroethane condensate to enter a collection tank, and enabling tail gas sulfur dioxide to enter a secondary condenser; 3, enabling tail gas and sulfur dioxide condensate flowing through the secondary condenser to enter a tertiary condenser at a temperature ranging from -25 DEG C to -30 DEG C, condensinggaseous sulfur dioxide into liquid sulfur dioxide, and sending into a recovery storage tank. The recovery method has advantages that hydrogen chloride in the tail gas is subjected to three-stage waterabsorption to obtain high-concentration hydrochloric acid while sulfur dioxide and trichloroethane in the tail gas are separated out, and accordingly the product conversion rate is increased, raw material and energy consumption is reduced, and cost is saved to the maximum extent.

Description

technical field [0001] The invention belongs to the field of food additive production, and relates to the production of sucralose, in particular to a recovery device for sulfur dioxide in the chlorination reaction of sucralose, and also relates to a recovery method for sulfur dioxide in the chlorination reaction of sucralose. Background technique [0002] Sucralose-6-ester, as a key intermediate in the production of sucralose, is prepared by chlorinating sucralose-6-ester and a chlorination reagent under suitable conditions. There are two types of commonly used chlorination reagents: one is Vi ls meier chlorination reagent, and the other is thionyl chloride / pyridine / chlorinated hydrocarbon ternary chlorination. Most domestic sucralose manufacturers use the first type of Vi lsmeier chlorination reagent as the raw material for chlorination reaction. [0003] Sulfur dioxide will be produced in the process of preparing Vi l s meier chlorinated reagent. At present, domestic tech...

AI Technical Summary

Problems solved by technology

Patent Publication No. CN106466548A provides a method for reclaiming liquid sulfur dioxide by cryogenic method, which saves a large amount of lye consumption and does not generate new waste, but finds that the following problems still exist in production: 1. Secondary The water content of trichloroethane in the condensed condensed gas is relatively high; 2. A small amount of HCl enters the primary condenser and the secondary condenser, which is highly corrosive to the cooling device; 3. The existence of a small amount of HCl not only shortens the cooling time of the cooling device. service life, and there are certain safety hazards

Images