Production method for thionyl chloride

Abstract

The invention belongs to the technical field of chemical production, and particularly relates to a production method for thionyl chloride. The production method comprises the following step: introducing synthesis gas generated by reaction, in a reaction kettle, of sulfur and chlorine gas, and sulfur dioxide gas into a reactor, and enabling a crude product thionyl chloride generated by the reactor to directly enter a splitter in the form of gas after passing through an absorption tower; introducing gas-phase crude product thionyl chloride from the splitter to enter a rectifying column, condensing gas-phase on the top of the rectifying tower, and introducing the condensed gas-phase into a reflux tank; introducing the gas phase in the reflux tank to enter a vacuum-pumping tank through an ejector and alloying a synthesis kettle in a circulating mode, and recovering a qualified product from the middle part of the rectifying column. According to the production method, a light component in the crude product thionyl chloride is converted into a heavy component through the adsorption tower, and pressure drop before and after conversion is relatively small, operation is easy, automation is easily realized and conversion is more complete by adopting the tower, so that the load of the rectifying system is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a production method of thionyl chloride. Background technique [0002] ZL95110380.6 discloses a manufacturing method of thionyl chloride, the method is to put the crude thionyl chloride obtained by cooling the thionyl chloride prepared by catalytic synthesis into the distillation still with sulfur powder added in advance, Distillation to obtain liquid thionyl chloride product. [0003] According to literature, in the preparation process of thionyl chloride, the crude thionyl chloride synthesized by the reactor is condensed and then subjected to batch rectification or rectification of two-stage rectification tower / three-stage rectification tower. [0004] During the preparation of thionyl chloride, the crude sulfur oxychloride in the gas phase from the reactor is condensed and sulfur mixed, and then the liquid phase is rectified, while the gas phase is rec...

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Problems solved by technology

[0004] During the preparation of thionyl chloride, the crude sulfur oxychloride in the gas phase from the reactor is condensed and sulfur mixed, and then the liquid phase is rectified, while the gas phase is recycled back to the reaction system; at the same time, the tail gas generated in the rectification process is condensed and then recycled to the reaction system. Reaction system, but it cannot condense all the tail gas, resulting in a certain material loss. The tail gas that has not been cooled needs to be emptied after water absorption and alkali absorption treatment. The process is relatively complicated and causes material loss; at the same time, too many condensers are used. The safety performance of the device is greatly reduced; the crude thionyl chloride is condensed and then gasified to cause a certain amount of steam consumption, and corresponding power equipment needs to be equipped with high energy consumption; if the gaseous crude thionyl chloride from the reactor directly enters The rectification tower increases the production load of the rectification tower; the finished product of thionyl chloride contains 0.3%-0.5% sulfuryl chloride

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