Process for pvc-containing mixed plastic waste pyrolysis
AssigneeUop LLC
InventorsPing Sun, Jeffrey Tyska, Joseph A. Montalbano
Life of this patent
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Abstract
A process for pyrolysis of a mixed plastic stream that contains polyvinyl chloride (PVC) is provided in which the chloride from PVC is removed from an initial melting reactor that heats the mixed plastic stream to a sufficient temperature to produce HCl but at a low enough temperature to avoid production of organochlorides. Chloride is primarily removed in a vapor stream from the initial melting reactor, while additional chloride removal may be removed downstream from the melting reactor by the use of sorbent addition to the pyrolysis reactor and by subsequent adsorbent beds.
Claims20
A process for producing low-chloride pyrolysis oil out of a mixed plastic waste stream comprising
- a. melting the mixed plastic waste stream with a hot product stream in a melting reactor to produce a melted mixed plastic waste stream comprising at least two types of plastic including chlorine-containing plastics and other plastics to produce a first chloride-rich vapor stream and a first liquid stream;
- b. sending said first liquid stream to a pyrolysis reactor to be heated with a hot product stream to produce a second chloride rich vapor stream, a second liquid stream and solid particles;
- c. sending part of the second liquid stream, comprising a circulation stream from said pyrolysis reactor, to said melting reactor and sending a part of the second liquid stream from said pyrolysis reactor to be heated and returned to said pyrolysis reactor;
- and
- d. passing main pyrolysis condensates through an adsorbent bed to remove residual chloride.
The process of claim 10 wherein said third liquid stream comprises less than about 200 ppmw chloride.
The process of claim 10 wherein said third liquid stream is sent to an adsorbent bed to remove chloride.
A process for pyrolysis of a mixed plastic waste stream comprising
- a. sending the mixed plastic waste stream to a melting reactor to produce a first vapor stream that is chloride-rich and a first liquid stream;
- b. sending the first liquid stream to a pyrolysis reactor to be heated to produce a second vapor stream, a second liquid stream and solid particles and wherein solid particles move in a downward direction within said pyrolysis reactor;
- and
- c. cooling and separating said second vapor stream into a third vapor stream and a third liquid stream and then treating said third liquid stream in at least one adsorbent bed to remove chlorine containing impurities;
- d. Mixing a portion of pyrolysis reactor liquid with the mixed plastic waste stream in the melting reactor providing temperatures needed to product the chloride-rich first vapor stream;
- and
- e. Sending a portion of pyrolysis reactor liquid to an external heater to heat and provide temperature needed in pyrolysis reactor and sending the heated stream back to mix with the first liquid from reactor effluent before both streams enter pyrolysis reactor.
A process for pyrolysis of a mixed plastic waste stream comprising
- a. sending the mixed plastic waste stream to a melting reactor to produce a first vapor stream that is chloride-rich and a first liquid stream;
- b. sending the first liquid stream to a pyrolysis reactor to be heated to produce a second vapor stream, a second liquid stream and solid particles and wherein solid particles move in a downward direction within said pyrolysis reactor;
- c. sending a portion of said second liquid stream to a heat exchanger and recycled to said pyrolysis reactor and sending a second portion of said second liquid stream to said melting reactor;
- and
- d. cooling and separating said second vapor stream into a third vapor stream and a third liquid stream and then treating said third liquid stream in at least one adsorbent bed to remove chlorine containing impurities.
Dependencies are inferred from the claim text.