Method for treating byproducts in process for preparing chloropropene by propylene chlorination

Abstract

The invention provides a method for treating byproducts in a process for preparing chloropropene by propylene chlorination. The method comprises the following steps: separating byproducts in a processof preparing chloropropene by propylene chlorination to obtain cis-1, 3, 5-triazolo[1, 2-a]pyridin-2-carboxylic acid. According to the method, trans-1, 3-dichloropropene reacts and is converted intotrans-1, 3-dichloropropene with higher additional value under the illumination condition and the catalytic action of the catalyst, so that the economic value of byproducts in the process of preparingchloropropene by propylene chlorination is improved, the cost of the whole process is greatly reduced, and the method has a good industrial application prospect.

Description

technical field [0001] The invention relates to the technical field of resource utilization, in particular to a method for treating by-products in the process of producing chloropropene by chlorination of propylene. Background technique [0002] In the synthesis process of propene chlorination to prepare allyl chloride, dried propene and chlorine are added to a high-temperature chlorination reactor under preheated conditions in a certain ratio (usually 5:1) to carry out rapid chlorination reaction. About 400-500 ° C, the product is mainly chloropropene and hydrogen chloride gas. [0003] After rectification in the above process, allyl chloride is obtained at the top of the tower, and the by-product DD mixture is obtained at the bottom of the tower. In the DD mixture, 1,2-dichloropropane and 1,3-dichloropropene reach more than 80%. To produce 1t of allyl chloride, 193kg of DD mixture can be obtained. [0004] DD is a halogenated hydrocarbon nematicide insecticide. The activ...

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Problems solved by technology

[0007] CN110498728A discloses a trans-1,3-dichloropropene compound and a cis-1,3-dichloropropene compound and a process flow thereof, the process adopts a three-tower continuous or four-tower continuous overall process, the first tower is a crude stripping tower , put the black raw material DD mixture (dichloropropane for industry) through the first tower to turn black into white and enter the second tower; In the heavy component, the material after weight removal enters the third tower for production; the third tower is a light removal tower; the material after weight removal enters the third tower for light removal, and 1,2-dichloropropane is removed. But the mixture of trans-1,3-dichloropropene and cis-1,3-dichloropropene obtained by this method has low added value of the product

[0008] In summary, it can be seen that most of the by-products in the synthesis process of propylene chloride for the preparation of chloropropene are currently focused on the separation and recovery of dichloropropene and dichloropropane, and have not realized the further improvement of their economic value.

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