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US4458095A Expired / Lapsed US ⏱️ 0.0 years remaining

Use of zinc and copper (I) salts to reduce sulfur and nitrogen impurities during the pyrolysis of plastic and rubber waste to hydrocarbons

Assignee: United States Department of Energy
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Filing: 1982-09-30
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Granted: 1984-07-03
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Expires: 2002-09-30
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Abstract

Abstract An improvement in a process for the pyrolytic conversion of rubber and plastic waste to hydrocarbon products which results in reduced levels of nitrogen and sulfur impurities in these products. The improvement comprises pyrolyzing the waste in the presence of at least about 1 weight percent of salts, based on the weight of the waste, preferably chloride or carbonate salts, of zinc or copper (I). This invention was made under contract with or subcontract thereunder of the Department of Energy Contract #DE-AC02-78-ER10049.

Inventors

  • 👤 Robert C. Wingfield, Jr.
  • 👤 Jacob Braslaw
  • 👤 Roy L. Gealer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 10:59
CPC Classifications
C; C10; C10G; C10G1/00; C10G1/10; C10G1/02

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 98 words
An improvement in a process for the pyrolytic conversion of waste selected from rubber and plastic to hydrocarbon products which results in reduced levels of nitrogen and sulfur impurities in said products, the improvement comprising pyrolyzing said waste at a temperature of between about 400° C. and about 700° C. in a pyrolysis zone through which inert gas is fowing in the presence of at least about 1 weight percent, based on the weight of said waste, of zinc or copper (I) salts for a time sufficient to pyrolyze said waste to char and volatile hydrocarbon- containing products.
Claim 2
Dependent Claim 98 words
An improvement in a process for the pyrolytic conversion of waste selected from rubber and plastic to hydrocarbon products which results in reduced levels of nitrogen and sulfur impurities in said products, the improvement comprising pyrolyzing said waste at a temperature of between about 400° C. and about 700° C. in a pyrolysis zone through which inert gas is fowing in the presence of at least about 1 weight percent, based on the weight of said waste, of zinc or copper (I) salts for a time sufficient to pyrolyze said waste to char and volatile hydrocarbon- containing products.
Claim 3
Dependent Claim 31 words
An improved process according to claim 1, wherein said salts are present in an amount of between about 1 and about 15 weight percent based on the weight of said waste.
Claim 4
Dependent Claim 32 words
An improved process according to claim 2, wherein said salts are present in an amount of between about 3 and about 7 weight percent based on the weight percent of said waste.
Claim 5
Dependent Claim 17 words
An improved process according to claim 1, wherein said salts comprise halides, carbonates, sulfates, acetates and phosphates.
Claim 6
Dependent Claim 16 words
An improved process according to claim 4, wherein said salts are selected from chloride and carbonates.
Claim 7
Dependent Claim 42 words
An improved process according to claim 1, wherein said waste is pyrolyzed in the presence of flowing inert gas which consists of a mixture of nitrogen and carbon dioxide obtained by burning a fuel gas mixture with a stoichiometric amount of air
Claim 8
Dependent Claim 19 words
An improved process according to claim 1, wherein said salts employed have a particle size below about 0.25 mm.
Claim 9
Dependent Claim 32 words
An improved process according to claim 1, wherein said salts soluble in water are employed as aqueous solutions thereof, said solution being admixed with said waste prior to pyrolysis of said waste.
Claim 10
Dependent Claim 26 words
An improved process according to claim 1, wherein at least a portion of said salts are admixed with said waste prior to pyrolysis of said waste.
Claim 11
Dependent Claim 27 words
An improved process according to claim 1 or 9, wherein at least a portion of said salts are admixed with said waste during pyrolysis of said waste.

References Cited (Backward Citations)

CA537244A Cited
US2276526A Cited
US2640010A Cited
US3193496A Cited
US4113606A Cited
SU632724A1 Cited
SU721460A1 Cited
US4204947A Cited
DE2925620A1 Cited
DE2944989A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-07-03 1988-01-02 1988-07-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-07-03 1992-01-02 1992-07-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-07-03 1996-01-02 1996-07-03 $7700.00 Window Closed / Lapsed

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