Method and device for removing impurity sulfur dichloride in thionyl chloride

Abstract

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. The method is as follows: the sulfur oxychloride gas containing 1 to 3% of sulfur dichloride steamed from the top of the rectification tower enters the oversulfur tank for reaction after heating up, the device includes a crude product receiving tank, and the crude product receiving tank passes through the pipeline and the distribution tank. The sulfur tank, rectification tower, heater, and oversulfur tank are connected in sequence, and a liquid sulfur line is installed on the top of the sulfur distribution tank. The invention can reduce the 1-3% sulfur dichloride contained in the thionyl chloride to less than 0.004%, which meets the requirement of 1# color of the superior product in the industry standard; solves the problem of pipeline blockage at the bottom of the oversulfurized tank , to achieve continuous production.

Description

Technical field [0001] The invention belongs to the technical field of chemical production, and specifically relates to a method and a device for removing sulfur dichloride impurities in thionyl chloride. Background technique [0002] Thionyl chloride is a commonly used chlorinating agent. Because the by-products of the reaction are only 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. As the use of thionyl chloride continues to expand, its quality requirements are getting higher and higher. [0003] Sulfur dichloride is the raw material for the synthesis of thionyl chloride by sulfur dioxide gas phase method, and it is also an impurity in the crude product of thionyl chloride. The reaction formula is Cl 2 +SCl 2 +SO 2 = 2SOCl 2 . Sulfur dichloride is reddish-brown wi...

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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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