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US 2024/0254306 A1Published application
Method for purifying reclaimed polymers
AssigneeThe Procter & Gamble Company
InventorsDimitris Ioannis COLLIAS, Norman Scott BROYLES, John Moncrief LAYMAN
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Abstract
A method for purifying a reclaimed polymer to a purer polymer is disclosed. In embodiments of the present invention, the method involves obtaining a reclaimed polymer, leaching various contaminants with a leaching solvent producing a leached polymer, and then dissolving the leached polymer in a solvent to produce a first solution comprising the dissolved polymer. The first solution is settled and then filtered. A purer polymer is separated from the resulting solution.
Claims22
A method for purifying a reclaimed polymer comprising:
- a. obtaining the reclaimed polymer;
- wherein the reclaimed polymer is selected from the group consisting of post-consumer reclaimed (PCR) polymers, post-industrial reclaimed (PIR) polymers, and combinations thereof;
- and wherein said reclaimed polymer comprises contaminants, each contaminant having a concentration;
- and wherein said reclaimed polymer contaminants comprise at least one of alkyl phenols, bisphenols, dioxins, PCBs, and phthalates;
- b. leaching said alkyl phenols, bisphenols, dioxins, PCBs, or phthalates from said reclaimed polymer with an average removal efficiency, at a temperature below the primary melting point of said reclaimed polymer and a pressure between about atmospheric and about 1,000 atm, using a leaching solvent, in a number of leaching stages, for a total residence time and residence time for each said leaching stage, to produce a leached polymer comprising at least one of alkyl phenols, bisphenols, dioxins, PCBs, or phthalates, each having a concentration;
- and wherein said average removal efficiency is greater than about 55%;
- c. dissolving the leached polymer in a solvent selected from the group consisting of the first fluid solvent, a second fluid solvent, and mixtures thereof, at a temperature from about 90° C. to about 280° C. and a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a first solution comprising a dissolved polymer, at least one dissolved contaminant, and at least one suspended contaminant;
- d. settling the first solution at a temperature from about 90° C. to about 280° C. and at a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a second solution comprising a settled polymer, at least one dissolved contaminant, and less of the at least one suspended contaminant;
- e. filtering the second solution by mechanical filtration at a temperature from about 90° C. to about 280° C. and at a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a third solution comprising a filtered polymer, at least one dissolved contaminant, and even less of the at least one suspended contaminant;
- f. filtering the third solution by adsorptive filtration at a temperature from about 90° C. to about 280° C. and at a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a fourth solution comprising a twice filtered polymer;
- and
- g. separating the twice filtered polymer from the fourth solution to produce a purer polymer;
- and wherein the second fluid solvent has the same chemical composition or a different chemical composition as the first fluid solvent.
10 more elements
A method for purifying a reclaimed polymer comprising:
- a. obtaining the reclaimed polymer;
- wherein the reclaimed polymer is selected from the group consisting of post-consumer reclaimed (PCR) polymers, post-industrial reclaimed (PIR) polymers, and combinations thereof;
- and wherein said reclaimed polymer comprises contaminants, each contaminant having a concentration;
- and wherein said reclaimed polymer contaminants comprise at least one of 4-tertpentylphenol, bisphenol A, OCDD, PCB 118, and 2-ethylhexyl phthalate;
- b. surface washing said reclaimed polymer in a non-densified state to produce a surface-washed polymer;
- wherein said surface washing results in a greater than about 80% reduction in loosely bound surface contamination;
- c. leaching said 4-tertpentylphenol, bisphenol A, OCDD, PCB 118, and 2-ethylhexyl phthalate from said reclaimed polymer with an average removal efficiency, at a temperature below the primary melting point of said reclaimed polymer and a pressure between about atmospheric and about 1,000 atm, using a leaching solvent, in a number of leaching stages, for a total residence time and residence time for each said leaching stage, to produce a leached polymer comprising at least one of 4-tertpentylphenol, bisphenol A, OCDD, PCB 118, and 2-ethylhexyl phthalate, each having a concentration;
- wherein said average removal efficiency is greater than about 55%;
- d. dissolving the leached polymer in a solvent selected from the group consisting of the first fluid solvent, a second fluid solvent, and mixtures thereof, at a temperature from about 90° C. to about 280° C. and a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a first solution comprising a dissolved polymer, at least one dissolved contaminant, and at least one suspended contaminant;
- e. settling the first solution at a temperature from about 90° C. to about 280° C. and at a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a second solution comprising a settled polymer, at least one dissolved contaminant, and less of the at least one suspended contaminant;
- f. filtering the second solution by mechanical filtration at a temperature from about 90° C. to about 280° C. and at a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) to produce a third solution comprising a filtered polymer, at least one dissolved contaminant, and even less of the at least one suspended contaminant;
- g. filtering the third solution by adsorptive filtration at a temperature from about 90° C. to about 280° C. and at a pressure from about 200 psig (1.38 MPa) to about 9,000 psig (62.05 MPa) by contacting the third solution with one or more solid media to produce a fourth solution comprising a twice filtered polymer;
- and
- h. separating the twice filtered polymer from the fourth solution to produce a purer polymer;
- and wherein the second fluid solvent has the same chemical composition or a different chemical composition as the first fluid solvent.
12 more elements
Dependencies are inferred from the claim text.