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EP-4739630-A1 - PROCESSES AND APPARATUSES FOR CONVERTING POLY- AND PERFLUOROALKYL SUBSTANCES

EP4739630A1EP 4739630 A1EP4739630 A1EP 4739630A1EP-4739630-A1

Abstract

Processes and apparatuses converting poly- and perfluoroalkyl substances (PFAS). An oxidation reaction zone, preferably a thermal oxidizer, is utilized to oxidize the PFAS into anionic fluoride species. A treatment zone is utilized on at least a portion of the oxidation zone effluent before the oxidation zone effluent is vented or otherwise released to the atmosphere. The treatment zone may include a dry sorbent injection zone; a selective catalytic reduction zone, a wet scrubber zone; a carbon bed; an ion exchange zone; or any combination thereof.

Inventors

  • JENSEN, ELIZABETH
  • Bennett, III, Erick J.
  • KOLEV, EVGENY T.
  • WHYMAN, William J.
  • FISHER, ARIC G.
  • SATTAR, AZIZ
  • NARTHASILPA, NINART
  • SANGER, ROBERT

Assignees

  • UOP LLC

Dates

Publication Date
20260513
Application Date
20240731

Claims (10)

  1. 1. A process for converting poly- and perfluoroalkyl substances (PFAS), the process comprising: oxidizing, in an oxidation zone (14, 295), a feed stream (12, 210) comprising liquid PFAS to provide an oxidation effluent (32, 310) comprising a reduced amount of liquid PFAS compared to the feed stream; and, treating the oxidation effluent (32, 310) in a treatment zone (40) to provide a treated effluent (44), wherein the treatment zone (40) comprises: a dry sorbent injection zone (545); a selective catalytic reaction zone (361); a wet scrubber zone (340); a carbon bed (360); an ion exchange zone (460); or any combination thereof .
  2. 2. The process of claim 1, wherein between 90 to 99.9999% of the PFAS in the feed stream is thermally oxidized in the oxidation zone (14, 295).
  3. 3. The process of claim 1, wherein the oxidizing is performed at a temperature between 500 °C to 2,300 °C.
  4. 4. The process of claim 1, wherein a residence time of the PFAS in the oxidation zone is between 0.1 to 30 seconds.
  5. 5. The process of claim 1 further comprising: cooling, in a thermal reduction zone (34, 305), the oxidation effluent (32, 310) before the treating in the treatment zone (40).
  6. 6. The process of any one of claims 1 to 5, wherein the treatment zone (40) comprises the dry sorbent injection zone (545) and wherein the process further comprises: mixing a reactant (535, 575) with the oxidation effluent (32, 310) to provide the treated effluent, and wherein the reactant includes a salt with sodium, calcium, potassium, magnesium, or any combination thereof in a solution or mixture.
  7. 7. The process of claim 6, wherein the reactant (535, 575) comprises a mixture of a fresh reactant (535) and a recycled reactant (575).
  8. 8. The process of any one of any of the foregoing claims, wherein the treatment zone (40) comprises the wet scrubber zone (340), and wherein the process further comprises: mixing an aqueous caustic stream (355) with the oxidation effluent (32, 310) to provide the treated effluent.
  9. 9. The process of claim 8, further comprising: separating the treated effluent into a liquid stream (350, 365, 805) and a vent gas stream (345), and optionally, recycling the liquid stream to the oxidation zone (14, 295).
  10. 10. The process of any one of any of the foregoing claims, wherein the treatment zone (40) comprises the carbon bed (360), the ion exchange zone (460), or both, and further comprises a sensor (700) configured to provide a measurement, and wherein the carbon bed (360) or the ion exchange zone (460) receive a portion of the treated effluent (44), and the process further comprising: determining a fluorine concentration in the liquid portion of the treated effluent from the measurement, monitoring the fluorine concentration in the liquid portion of the treated effluent, and adjusting a process condition when the fluorine concentration is outside of a predetermined range.

Description

PROCESSES AND APPARATUSES FOR CONVERTING POLY- AND PERFLUOROALKYL SUBSTANCES STATEMENT OF PRIORITY [0001] This application claims priority to U.S. Non-Pro visional Patent Application Ser. No. 18/620,189 filed on March 28, 2024, which claims priority to U.S. Provisional Patent Application Ser. No. 63/518,029 filed on August 7, 2023, the entirety of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] This invention relates generally to processes and apparatuses for removing and converting poly- and perfluoroalkyl substances. BACKGROUND OF THE INVENTION [0003] Poly- and perfluoroalkyl substances (“PFAS”) are “forever chemicals” that are very stable and persist in the environment. These forever chemicals are linked to harmful effects on the kidney, liver, blood, and immune system. Examples of such chemicals are surfactants in industrial and consumer products, such as firefighting foams, alkaline cleaners, paints, non-stick cookware, carpets, upholstery, shampoos, floor polishes, fume suppressants, semiconductors, photographic films, pesticide formulations, food packing, masking tape, and denture cleaners. [0004] The EPA has a list of over 179 PFAS that are known or believed to be toxic and it is believed that this list will grow as there are more than 12,000 different PFAS. Currently, the EPA advises a maximum limit of <70 ppt of PFAS, however stricter EPA regulations and limits have been proposed. [0005] Given the health risks associated with PFAS and their environmental impact, there is an ongoing need for processes and apparatuses which effectively and efficiently remove and convert PFAS. SUMMARY OF THE INVENTION [0006] The present invention provides for the removal and conversion of PFAS. The PFAS may be oxidized in a thermal oxidizer and then the oxidation effluent is subjected to a treatment in a treatment zone. The treatment zone may include a dry sorbent injection zone, a wet scrubber zone, a carbon bed, a selective catalytic reaction zone, and/or an ion exchange zone. [0007] The present processes may be utilized with liquid PFAS, allowing streams to be injected into a thermal oxidizer, without requiring separate vaporizing equipment. Further the direct injection reduces the residence time and minimizes the size of the apparatus needed. [0008] Therefore, the present invention may be characterized, in at least one aspect, as providing a process for converting poly- and perfluoroalkyl substances (PFAS) by: oxidizing, in an oxidation zone, a feed stream comprising liquid PFAS to provide an oxidation effluent comprising a reduced amount of liquid PFAS compared to the feed stream; and, treating the oxidation effluent in a treatment zone to provide a treated effluent, wherein the treatment zone comprises: a dry sorbent injection zone; a selective catalytic reaction zone; a wet scrubber zone; a carbon bed; an ion exchange zone; or any combination thereof. [0009] Between 90 to 99.9999% of the PFAS in the feed stream may be thermally oxidized in the thermal oxidation zone. [00010] The oxidizing may be performed at a temperature between 500 °C to 2,300 °C. [00011] A residence time of the PFAS in the thermal oxidation zone may be between 0.1 to 30 seconds. [00012] The process may further include cooling, in a thermal reduction zone, the oxidation effluent before the treating in the treatment zone. [00013] The treatment zone may include the dry sorbent injection zone and the process may include: mixing a reactant with the oxidation effluent to provide the treated effluent, and wherein the reactant includes a salt with sodium, calcium, potassium, magnesium, aluminum, silicon or any combination thereof in a solution or mixture. The reactant may be a mixture of a fresh reactant and a recycled reactant. The process may include quenching the treated effluent from the treatment zone. The dry sorbent injection zone may include a filtration zone configured to separate the treated effluent and provide a residue stream and a vent gas stream. The process may include recycling the residue stream to the dry sorbent injection zone as at least a portion of the reactant. The treatment zone may include the selective catalytic reaction zone, and the selective catalytic reaction zone may receive the vent gas stream from the filtration zone. [00014] The treatment zone may include the wet scrubber zone, and the process may also include mixing an aqueous caustic stream with the oxidation effluent to provide the treated effluent. The aqueous caustic stream may include sodium, calcium, potassium, magnesium, or any combination thereof. The process may include separating the treated effluent into a liquid stream and a vent gas stream. The liquid stream may be mixed with the feed stream before introducing the feed stream to the thermal oxidation zone, or wherein the liquid stream may be passed as a quench fluid into the thermal oxidation zone, or both. The treatment zone may include the carbon bed, the ion exchange z