Method for producing chloromethyl ether from sucralose chlorination tail gas

[0020] Example 1:

[0021] Such as figure 1 As shown, the tail gas produced by the chlorination reaction of sucralose is first condensed (condensed to 1-5°C) to remove the organic solvent 1,1,2-trichloroethane in the tail gas, and then dehydrated by concentrated sulfuric acid. The hydrogen chloride and sulfur dioxide gas is pressurized to 0.6MPa by a compressor, and then sent to the freezer to be condensed to -35°C to obtain sulfur dioxide liquid and pure hydrogen chloride gas.

[0022] Add the prepared formaldehyde and methylal solution into the first-stage reaction tower, and continuously pass the hydrogen chloride gas after freezing and separation into the first-stage reaction tower, and add the prepared 37% formaldehyde and methylal into the first-stage reaction tower. The aldehyde solution is sprayed and reacted to form a chloromethyl ether solution. The temperature of the first-stage reaction tower is controlled at 5℃~12℃, and the liquid level is controlled at 35%;

[0023] Afte

[0027] Example 2:

[0028] Add the prepared 37% formaldehyde and methylal solution to the primary reaction tower, and the purified hydrogen chloride gas from the chlorination tail gas and the chloromethyl ether, formaldehyde and methylal solution from the secondary reaction tower are in a molar ratio of 1.2: 0.5: 0.5 enters the tower, the chloromethyl ether, formaldehyde, and methylal solutions from the secondary reaction tower enter from the inlet of the tower at a flow rate of 1.5m³ / h, and hydrogen chloride gas flows from the bottom gas phase at a flow rate of 60m³ / h The formaldehyde and methylal solution pre-filled at the bottom of the tower are lifted to the top of the tower by a circulating pump at the bottom of the tower for cyclic absorption. After the materials are cyclically absorbed for about 5 hours, they will be sampled and analyzed, and then continuously extracted. 2 The graphite heat exchanger cools the circulating liquid at the bottom of the tower, the temperature