Method for removing sulfur dioxide (SO2) from trifluoroacetyl chloride (TFAC)

By employing distillation and adsorption methods to form azeotropic compositions, sulfur dioxide is removed from trifluoroacetyl chloride, addressing catalyst interference and enhancing the production of trifluoromethyliodide.

JP7888537B2Active Publication Date: 2026-07-13HONEYWELL INTERNATIONAL INC
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Patent Information

Application Number
JP2023515687
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2021-09-03
Filing Date
2021-09-10
Publication Date
2026-07-13
Estimated Expiration
2041-09-10

AI Technical Summary

Technical Problem

The presence of sulfur dioxide (SO2) impurities in trifluoroacetyl chloride (TFAC) adversely affects catalysts used in the production of trifluoromethyliodide, leading to undesirable side reactions and catalyst poisoning.

Method used

The removal of sulfur dioxide from trifluoroacetyl chloride is achieved through distillation, adsorption, or a combination thereof, forming azeotropic or azeotropic-like compositions with TFAC and SO2, which can be used to purify TFAC for subsequent reactions.

Benefits of technology

The method effectively reduces SO2 levels in TFAC to enhance the production of trifluoromethyliodide by preventing catalyst degradation and improving reaction efficiency.

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Abstract

Impurities such as sulfur dioxide (SO2) are removed from trifluoroacetyl chloride (TFAC) through distillation, adsorption, or a combination thereof, and / or the formation of an azeotropic or azeotrope-like composition containing effective amounts of sulfur dioxide (SO2) and trifluoroacetyl chloride (TFAC). The thus purified trifluoroacetyl chloride (TFAC) can then be used in the production of trifluoroiodomethane (CF3I). Azeotropic and azeotrope-like compositions of sulfur dioxide (SO2) and trifluoroacetyl chloride (TFAC) are also disclosed.
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Citation Information

Patent Citations

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    CN108311098A

  • Process for the preparation of perhalocarboxylic acid fluorides or chlorides, the halogen content of which consists of more than 50 mol% fluorine

    DE1020970B

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    JP2017525720A

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    US20200062679A1

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