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EP-4739623-A1 - INTEGRATED PROCESS FOR CO-PRODUCING PHOSPHORUS PENTAFLUORIDE (PF5) AND FLUOROSULFONIC ACID (HSO3F)

EP4739623A1EP 4739623 A1EP4739623 A1EP 4739623A1EP-4739623-A1

Abstract

An integrated process for co-producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSOsF) in high yield and purity via a single reaction step is provided. The method includes reacting a first reagent comprising an aqueous solution of hexafluorophosphoric acid (HPFG) and hydrofluoric acid (HF) with a second reagent comprising fuming sulfuric acid (H 2 SO 4 *SO 3 ) and recovering a product mixture comprising phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO 3 F).

Inventors

  • WANG, HAIYOU
  • POINTNER, Bernard
  • YU, Xinrui
  • MAHDAVI-SHAKIB, Akbar

Assignees

  • Solstice Advanced Materials US, Inc.

Dates

Publication Date
20260513
Application Date
20240628

Claims (15)

  1. 1 . An integrated process for co-producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) comprising: (1) reacting anhydrous hydrofluoric acid (AHF) with polyphosphoric acid (H3PO4) in a first reactor to produce a first product mixture comprising hexafluorophosphoric acid (HPFe); and (2) reacting the first product mixture with oleum (FkSCU’SOs) in a second reactor to produce a second product mixture comprising phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F).
  2. 2. The process of claim 1 , further comprising, after the reaction step (2), the additional step of conveying the second product mixture to a distillation column to recover purified fluorosulfonic acid (HSO3F).
  3. 3. The process of claim 2, wherein the recovered fluorosulfonic acid (HSO3F) is greater than about 99% pure as determined by NMR spectroscopy.
  4. 4. The process of claim 1 , further comprising, after the reaction step (2), the additional step of conveying the second product mixture is to a distillation column to recover purified difluorophosphoric acid (HPO2F2).
  5. 5. The process of claim 1 , wherein the first reacting step (1 ) utilizes a stoichiometric excess of anhydrous hydrofluoric acid (AHF) relative to the amount of polyphosphoric acid (H3PO4).
  6. 6. The process of claim 1 , wherein the polyphosphoric acid (H3PO4) is at a temperature of about 40°C to about 60°C before reacting with anhydrous hydrofluoric acid (HF) in the first reacting step (1 ).
  7. 7. The process of claim 1 , wherein the first reacting step (1 ) is conducted at a temperature of 20°C to 50°C.
  8. 8. The process of claim 1 , wherein the second product mixture comprises phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) in a ratio of from about 60 wt.%:40 wt.% to about 80 wt.%:20 wt.%, based on a total weight of the phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) in the second product mixture.
  9. 9. The process of claim 1 , wherein the phosphorus pentafluoride (PFs) in the second product mixture is recovered in the gas phase.
  10. 10. The process of claim 9, wherein the recovered phosphorus pentafluoride (PFs) is greater than about 99% pure as determined by FTIR spectroscopy.
  11. 11 . The process of claim 1 , wherein the fluorosulfonic acid (HSO3F) in the second product mixture is in the liquid phase.
  12. 12. The process of claim 1 , wherein the product mixture further comprises H2PO3F, difluorophosphoric acid (HPO2F2), phosphoryl fluoride (POF3), sulfuric acid (H2SO4), fluorosulfonic acid (HSO3F), and combinations of the foregoing.
  13. 13. The process of claim 1 , wherein the second product mixture is substantially free of hydrofluoric acid (HF).
  14. 14. The process of claim 1 , wherein the second product mixture is substantially free of phosphoryl fluoride (POF3).
  15. 15. A process for co-producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) comprising: (1 ) reacting hexafluorophosphoric acid (HPFe) with oleum (H2SO4*SO3) in a reactor; (2) collecting an overhead stream comprising phosphorus pentafluoride (PFs) from the reactor; and (3) collecting a bottoms stream comprising fluorosulfonic acid (HSO3F) from the reactor.

Description

INTEGRATED PROCESS FOR CO-PRODUCING PHOSPHORUS PENTAFLUORIDE (PFs) AND FLUOROSULFONIC ACID (HSO3F) CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. Patent Application No. 18/744,606, filed June 15, 2024, which claims the benefit under 35 U.S.C. § 119(e) of Provisional Application No. 63/525,047, filed July 5, 2023, both of which are herein incorporated by reference in their entireties. FIELD [0002] The present disclosure relates to the raw materials phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) and to an integrated process for co-producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F). BACKGROUND [0003] Among commercially produced batteries, lithium ion batteries have one of the best energy-to-weight ratios, no memory effect, and a slow loss of charge when not in use. In addition to powering a wide variety of consumer electronics, lithium ion batteries are growing in popularity for defense, automotive, and aerospace applications due to their high energy density. [0004] Lithium hexafluorophosphate (LiPFs) and lithium bis(fluorosulfonyl)imide (LiFSI) are two electrolytes often used in lithium ion batteries. Phosphorus pentafluoride (PFs) can be used to produce lithium hexafluorophosphate (LiPFs), while fluorosulfonic acid (HSO3F) can be used to make hydrogen bis(fluorosulfonyl)imide (HFSI), an intermediate that can be used to produce lithium bis(fluorosulfonyl)imide (LiFSI). There continues to be a need for lithium salts for use in electrolyte solutions. However, many existing methods produce undesirable side products such as hydrofluoric acid (HF) or phosphoryl fluoride (POF3) which require energy intensive and costly purifications to remove. [0005] Applicants appreciate the need for producing the raw materials needed for manufacture of lithium ion batteries in high yield and purity, including phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F). SUMMARY [0006] The present disclosure provides an integrated process for the coproduction of phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) from oleum (H2SO4-SO3) and an aqueous solution containing hydrofluoric acid (HF) and hexafluorophosphoric acid (HPFe). [0007] In one form thereof, the present disclosure provides an integrated process for co-producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) comprising: (1 ) reacting anhydrous hydrofluoric acid (AHF) with polyphosphoric acid (H3PO4) in a first reactor to produce a first product mixture comprising hexafluorophosphoric acid (HPFe); and (2) reacting the first product mixture with oleum (H2SO4*SO3) in a second reactor to produce a second product mixture comprising phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F). [0008] In another form thereof, the present disclosure provides a process for co-producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) comprising: (1 ) reacting hexafluorophosphoric acid (HPFe) with oleum (H2SO4*SO3) in a reactor; (2) collecting an overhead stream comprising phosphorus pentafluoride (PFs) from the reactor; and (3) collecting a bottoms stream comprising fluorosulfonic acid (HSO3F) from the reactor. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The above mentioned and other features of the disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of embodiments of the disclosure taken in conjunction with the accompanying drawings. [0010] FIG. 1 is a schematic diagram of an integrated process for producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) which corresponds to Example 5. [0011] FIG. 2 is a schematic diagram of an integrated process for producing phosphorus pentafluoride (PFs) and fluorosulfonic acid (HSO3F) which corresponds to Example 6. [0012] FIG. 3 is a 19F NMR spectrum of autoclave contents after the completion of the reaction from Example 2a. [0013] FIG. 4 is a 31 P NMR spectrum of autoclave contents after the completion of the reaction from Example 2a. [0014] FIG. 5 is a FTIR spectrum of recovered product from the product collection cylinder from Example 2a. [0015] The exemplification set out herein illustrates an embodiment of the disclosure, and such exemplification is not to be construed as limiting the scope of the disclosure in any manner. DETAILED DESCRIPTION I. Definitions [0016] As used herein, the term “about”, when used in connection with numerical values such as recited weight percentages of the components of the present compositions, pressures, and temperatures includes a deviation of ± 0.3 % from the recited weight percentage. [0017] As used herein, the singular forms “a”, “an” and “the” include plural unless the context clearly dictates otherwise. Moreover, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable