Method and device for removing impurity-sulfur dichloride in thionyl chloride

Abstract

The invention belongs to the technical field of chemical production, and specifically relates to a method and a device for removing the impurity-sulfur dichloride in thionyl chloride. The method comprises the step of enabling thionyl chloride gas which is evaporated from the top part of a rectifying tower and contains 1 to 3 percent of sulfur dichloride to be subjected to temperature rising and to enter an over-vulcanization tank for reaction. The device comprises a crude product receiving tank, wherein the crude product receiving tank is sequentially connected with a sulfur preparing tank, the rectifying tower, a heater and the overvulcanization tank through pipelines; the top part of the sulfur preparing tank is provided with a hydraulic sulfur line. According to the method and the device, disclosed by the invention, 1 to 3 percent of sulfur dichloride which is contained in the thionyl chloride can be reduced to be below 0.004 percent; the requirement on color I of excellent products in industry standard is achieved; the problem that a pipeline arranged at the bottom part of the sulfur preparing tank is blocked can be solved, and continuous production is realized.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a method and a device for removing impurity sulfur dichloride in thionyl chloride. Background technique [0002] Thionyl chloride is a commonly used chlorinating agent. Because the reaction by-products are only two gases, sulfur dioxide and hydrogen chloride, it is easy to separate from the target product. It is widely used in the synthesis and production of medicines, pesticides, dyes and food additives. In recent years, It has also been widely used in the lithium battery industry. With the continuous expansion of the use of thionyl chloride, the quality requirements for it are also getting higher and higher. [0003] Sulfur dichloride is the raw material for the synthesis of sulfur oxychloride by the gas phase method of sulfur dioxide, and it is also an impurity in the crude product of sulfur oxychloride. The reaction formula is: Cl 2 +SCl 2 +SO 2 =2...

AI Technical Summary

Problems solved by technology

[0008] (1) The specific conditions for the conversion of sulfur dichloride and solid sulfur into sulfur monochloride are not given, and the complete removal of sulfur dichloride cannot be ensured

[0009] (2) When the device is shut down and started up again, due to the temperature drop of the pipeline, the oversulfurization tank and the solid sulfur in it, some of the gas will condense, and the condensed material will wash the solid sulfur to the bottom of the oversulfurization tank, causing the pipeline road congestion, especially in winter

However, when the phenomenon of flushing is serious, it will still cause the blockage of the bottom pipeline of the rectification tower and even the packing in the tower

Moreover, it is very inconvenient to add sulfur by setting the oversulfur tank on the top of the tower more than 20 meters high.

[0010] (3) In the above-mentioned patents, when adding sulfur to the oversulfur tank, the vehicle must be stopped, and the pressure in the oversulfur tank must be discharged to the exhaust gas absorption system before proceeding, and continuous production cannot be realized

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