A method for combined recovery and utilization of tetrafluoroethylene and hexafluoropropylene production residue

Abstract

The invention relates to a jointly recycling method for a residual liquid in production of tetrafluoroethylene and hexafluoropropylene. According to the method, the residual liquid generated in production of tetrafluoroethylene is introduced to a production process of hexafluoropropylene and is rectified and recovered with the residual liquid generated in production of hexafluoropropylene to recover octafluorocyclobutane without independent equipment and process operations, so that octafluorocyclobutane in the tetrafluoro residual liquid can be recovered with a low cost. The recovered octafluorocyclobutane contains minute quantity of similar components. Being specially matched with a tetrafluoroethylene monomer, the quality of hexafluoropropylene is not affected, and the octafluorocyclobutane can be directly used for producing hexafluoropropylene, so that perfect fusion of the production process of hexafluoropropylene and the recovery process of the residual liquid is realized. Moreover, separation and recovery are more simplified and reliable.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for combined recovery and utilization of tetrafluoroethylene and hexafluoropropylene production residual liquid. Background technique [0002] After the pyrolysis product in the production of tetrafluoroethylene is rectified to distill tetrafluoroethylene and recover difluorochloromethane, the remaining part is used as a raffinate. Although it contains various components, it is affected by factors such as difficult separation, high cost, and unstable market. , often directly sent to incineration, the method of direct incineration not only wastes a large amount of recyclable raw materials (about half of the raffinate is octafluorocyclobutane), improves production costs, but also causes environmental pollution. At present, it has been proposed to adopt a rectification method to reclaim the octafluorocyclobutane in the raffinate, such as the extractive distillation method p...

AI Technical Summary

Problems solved by technology

[0002] After the pyrolysis product in the production of tetrafluoroethylene is rectified to distill tetrafluoroethylene and recover difluorochloromethane, the remaining part is used as a raffinate. Although it contains various components, it is affected by factors such as difficult separation, high cost, and unstable market. , often directly sent to incineration, the method of direct incineration not only wastes a large amount of recyclable raw materials (about half of the raffinate is octafluorocyclobutane), increases production costs, but also causes environmental pollution

At present, it has been proposed to adopt a rectification method to reclaim the octafluorocyclobutane in the raffinate, such as the extractive distillation method proposed by the patent CN101134710A, but this complex rectification method carries out sufficient and high-purity reclaimed octafluorocyclobutane, which introduces For new substances, the process is long and the system is more complicated. For the residual liquid with a small total amount, the useful components can be recovered at a high cost, which greatly reduces the effect of reducing production costs and is easily affected by market fluctuations of recovered components.

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