Granted Patent B2

US 12,668,677 · App. 17/996,656 · Granted Jun 30, 2026

Inventors: Bruce Roger DeBruin (Gray, TN); Daryl Bitting (Longview, TX); David Eugene Slivensky (Tatum, TX); Xianchun Wu (Longview, TX); Michael Paul Ekart (Kingsport, TN); David Milton Lange (Blountville, TN); Aaron Nathaniel Edens (Weber City, VA)

Assignee: ExxonMobil Product Solutions Company

C08J11/06B01D19/0005C08J2323/06

Abstract

Claims (16)

1 . A waste plastic dehalogenation process comprising:

(a) liquefying solid waste plastic in a melt tank to produce a liquefied waste plastic;

(b) circulating said liquified waste plastic through a circulation loop external to the melt tank, said circulation loop including a halogen stripper;

(c) sparging a stripping gas into said halogen stripper and through the liquefied waste plastic in the external halogen stripper to produce a multi-phase mixture, wherein sparging uses a sparger inside the halogen stripper, wherein the sparger comprises a sparger tube and sparger apertures, wherein the sparger apertures are positioned below a lateral axis of the sparger tube at an angle from 10 to 50 degrees relative to a horizontal axis; and

(d) disengaging a gaseous phase from a liquid phase of said multi-phase mixture to thereby provide a halogen-enriched gaseous material and a halogen-depleted liquefied waste plastic.

2 . The process according to claim 1 , wherein said stripping gas comprises nitrogen, steam, methane, carbon monoxide, hydrogen, or a combination thereof.

3 . The process according to claim 1 , wherein said liquefying comprises liquefying at least a portion of said solid waste plastic in the melt tank, wherein the liquified waste plastic in said melt tank is maintained at a temperature of 200 to 500° C.

4 . The process according to claim 3 , comprising a melting system comprising a heat exchanger outside of said melt tank, wherein said liquefying comprises: (i) circulating said liquefied waste plastic through said melt tank and said heat exchanger in said circulation loop and (ii) heating said liquefied waste plastic in said heat exchanger while circulating in said circulation loop.

5 . The process according to claim 4 , wherein said sparging is carried out in said halogen stripper located downstream of said heat exchanger and upstream of said melt tank.

6 . The process according to claim 4 , wherein said disengaging is carried out in said circulation loop using a disengagement vessel located downstream of said halogen stripper and upstream of said melt tank.

7 . The process of claim 5 , wherein said halogen-depleted liquefied waste plastic has a halogen content of not more than 100 ppmw.

8 . The process of claim 1 , wherein said disengaging is carried out in said circulation loop using a disengagement vessel located downstream of said halogen stripper and upstream of said melt tank, and a portion of the halogen-depleted liquid phase is discharged from an outlet of the disengagement vessel and returned to the melt tank, and a halogen-enriched gaseous material stream is removed from an outlet of the disengagement vessel.

9 . The process of claim 1 , wherein said disengaging is carried out in said circulation loop using a disengagement vessel located downstream of said halogen stripper and upstream of said melt tank, and a portion of the halogen-depleted liquid phase is reintroduced into the melt tank and/or sent downstream for further processing, and a halogen-enriched gaseous material stream is removed from an outlet of the disengagement vessel.

10 . The process according to claim 1 , wherein said liquefying comprises liquefying at least a portion of said solid waste plastic in a melt tank in presence of at least one dissolution solvent, wherein said dissolution solvent comprises a pyrolysis oil, an overall feed stream introduced into liquification system comprises 1 to 50 weight percent of the at least one dissolution solvent, based on a total weight of the overall feed stream.

11 . The process according to claim 10 , wherein the circulation loop external to the melt tank comprises a heat exchanger outside the melt tank and (b) circulating said liquefied waste plastic through said melt tank and said heat exchanger in the circulation loop and (ii) heating said liquefied waste plastic in said heat exchanger while circulating in said circulation loop.

12 . The process according to claim 11 , wherein at least a portion of the halogen-depleted liquefied waste plastic is returned to the melt tank for further liquefying and at least a portion of the halogen-depleted liquefied waste plastic is removed for further processing in a downstream facility; wherein a ratio of the halogen-depleted liquefied waste plastic returned to the melt tank to the halogen-depleted liquefied waste plastic removed is in the range of 0.1:1 to 40:1.

Assignments (2)

Continuity (2)

References Cited (210)