Process for simultaneously processing of used metal and/or metal _scrap and scrap containing halogenated hydrocarbons

• US 4,317,800 A
• Filed: 09/15/1980
• Issued: 03/02/1982
• Est. Priority Date: 10/05/1977
• Status: Expired due to Term

• Current Assignee: Esdex VOF de Klencke 4 1983 HH Amsterdam Netherlands
• Original Assignee: Esmil BV (TATA Steel Limited)
• Inventors: Dapper, Gerrit, Verbraak, Cornelis A., Sloterdijk, Wijtze, Kirchner, Willem
• Primary Examiner(s): Hearn, Brian E.
• Application Number:
  US06/187,406
• Time in Patent Office: 533 Days
• Field of Search: 423/44, 423/60, 423/75, 423/76, 423/96, 423/97, 423/107, 423/149, 423/491-494, 423/481, 75/111, 75/43 S, 75/63, 75/64, 201/15, 201/30, 201/2.5
• US Class Current: 588/316
• CPC Class Codes: C10B 47/06 in retorts
• CPC Class Codes: C10B 53/00 Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form wet carbonising of peat C10F
• CPC Class Codes: C10B 53/07 of solid raw materials consisting of synthetic polymeric materials, e.g. tyres waste in general, e.g. household waste C10B53/00; recovery or working-up of waste materials of organic macromolecular compounds or compositions based thereon by dry-heat treatment for obtaining partially depolymerised materials C08J11/10; production of liquid hydrocarbon mixtures from rubber or rubber waste C10G1/10
• CPC Class Codes: C22B 1/08 Chloridising roasting
• CPC Class Codes: C22B 7/002 by treating with halogens, sulfur or compounds thereof; by carburising, by treating with hydrogen (hydriding)
• CPC Class Codes: H01B 15/003 by heating up
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02P 20/143 the feedstock being recycled material, e.g. plastics
• CPC Class Codes: Y02W 30/82 Recycling of waste of electrical or electronic equipment [WEEE]

Abstract

A process for reducing environmental pollution resulting from disposal of waste containing halogenated hydrocarbons by simultaneous treatment with used metal and/or metal scrap at elevated temperatures. The halogenated hydrocarbons are pyrolyzed and the resulting hydrogen halide containing gas is brought into contact with the used metal and/or metal scrap at elevated temperatures so as to form metal halogenides that are volatile under the conditions applied. The volatile metal halogenides are largely separated from the gaseous mixture formed, and at least part of the remaining gaseous mixture and/or hydrocarbon residue is used as fuel to maintain the required temperature. The waste feed compositions and process conditions can be chosen to effect separation between various metals by selective halogenation and condensation, and substantially all of the hydrogen halide can be tied up and recovered as metal halogenides.

Claims

1. A process for the disposal of waste material containing halogenated hydrocarbon by pyrolysis in the absence of molecular oxygen by the combination of steps of:

introducing said waste halogenated hydrocarbon into a pyrolysis zone wherein it is heated to a temperature at least sufficient to form a pyrolysis zone off-gas containing halide substantially all in the form of gaseous hydrogen halide, and a pyrolysis zone residue;

introducing waste metal into a heating zone wherein it is heated to a halogenation temperature whereat at least one component of said waste metal will react with said hydrogen halide to form the corresponding metal halogenide;

contacting said heated waste metal in a halogenation zone, which is separate from said pyrolysis zone, with said hydrogen halide containing pyrolysis zone off-gas whereby at least a portion of said waste metal is converted into at least one metal halogenide which is vaporized under the temperature applied, thereby forming a metal halogenide containing gas;

separating metal halogenide by condensation from said metal halogenide containing gas leaving a residual gas stream; and

utilizing at least a portion of the fuel value of said halogenated hydrocarbon to provide heat to at least one of said zones;

wherein the composition, quantity, and temperature of said heated waste metal in said halogenation zone is chosen so as to convert substantially all of said gaseous hydrogen halide into metal halogenide.

2. The process of claim 1 wherein said halogenated hydrocarbon is heated in said pyrolysis zone to a temperature sufficient to additionally decompose said halogenated hydrocarbon into gaseous hydrocarbons, and said gaseous hydrocarbons are burned to provide heat to at least one of said zones.

3. The process of claim 1 wherein said halogenated hydrocarbon component is heated in said pyrolysis zone to a temperature of at most about 350°

C. to drive off the hydrogen halide, and the remaining pyrolysis zone residue is removed from said pyrolysis zone and burned to provide heat to at least one of said zones.

4. The process of claim 3 wherein said pyrolysis zone residue is burned so as to produce a hot reducing gas which is introduced into said heating zone to directly heat said waste metal.

5. A process for the disposal of waste material containing halogenated hydrocarbons by pyrolysis in the absence of molecular oxygen by the combination of steps of:

introducing said waste halogenated hydrocarbon into a pyrolysis zone wherein it is heated to a temperature at least sufficient to form a pyrolysis zone off-gas containing halide substantially all in the form of gaseous hydrogen halide, and a pyrolysis zone residue;

introducing waste metal into a heating zone wherein it is heated to a halogenation temperature whereat at least one component of said waste metal will react with said hydrogen halide to form the corresponding metal halogenide;

contacting said heated waste metal in a halogenation zone, which is separate from said pyrolysis zone, with said hydrogen halide containing pyrolysis zone off-gas whereby at least a portion of said waste metal is converted into at least one metal halogenide which is vaporized under the temperature applied, thereby forming a metal halogenide containing gas;

separating metal halogenide by condensation from said metal halogenide containing gas leaving a residual gas stream;

utilizing at least a portion of the fuel value of said halogenated hydrocarbon to provide heat to at least one of said zones;

wherein any hydrogen halide still contained in said residual gas sream is utilized for the halogenation of a further amount of waste metal to metal halogenide.

6. The process of claim 5 wherein said hydrogen halide still contained in said residual gas stream is absorbed and retained for subsequent use for the halogenation of a further amount of waste metal to metal halogenide.

7. A process for the disposal of waste material containing halogenated hydrocarbon by pyrolysis in the absence of molecular oxygen by the combination of steps of:

introducing said waste halogenated hydrocarbon into a pyrolysis zone wherein it is heated to a temperature at least sufficient to decompose said halogenated hydrocarbon to form a pyrolysis gas containing halide, substantially all in the form of gaseous hydrogen halide, together with a combustible hydrocarbon gas;

introducing waste metal into said pyrolysis zone wherein it is heated, together with said halogenated hydrocarbon, to a temperature whereat at least one component of said waste metal will react with said hydrogen halide to form the corresponding metal halogenide;

contacting said heated waste metal in said pyrolysis zone with said hydrogen halide containing pyrolysis gas in a manner such that substantially all of said hydrogen halide and at least a portion of said waste metal is converted into at least one metal halogenide which is vaporized under the temperature applied;

removing from said pyrolysis zone a gas stream containing said metal halogenide and said combustible gas, and separating metal halogenide therefrom by condensation leaving a residual gas stream containing said combustible gas; and

utilizing at least a portion of said residual gas stream to provide heat to said pyrolysis zone.

8. The process of claim 7 wherein said heated waste metal is initially comprised of at least two metal components and is heated to a first temperature whereat one of said metal components is selectively converted to a first metal halogenide in preference to the remainder of said metal components, and said first metal halogenide is condensed and separated from the metal halogenide containing gas.

9. The process of claim 8 wherein said heated waste metal is initially comprised of at least three metal components, and the remainder of said metal components is thereafter heated to a second temperature whereat a second of said metal components is selectively converted to a second metal halogenide, and said second metal halogenide is condensed and separated from the metal halogenide gas separately from said first metal halogenide.

10. The process of claim 7 wherein said heated waste metal is initially comprised of a plurality of metal components and is heated to a temperature whereat at least two of said metal components are converted to their respective metal halogenides, and said metal halogenide containing gas is cooled to a first condensation temperature whereat a first metal halogenide is selectively condensed and separated leaving a remaining metal halogenide containing gas, and said remaining gas is further cooled to a second condensation temperature whereat a second metal halogenide is selectively condensed and separated from said remaining gas.

11. The process of claim 7 wherein any minor amount of hydrogen halide remaining in said residual gas stream is removed by absorption.

12. A process for the disposal of waste material containing halogenated hydrocarbon by pyrolysis in the absence of molecular oxygen by the combination of steps of:

introducing said waste halogenated hydrocarbon into a pyrolysis chamber wherein said halogenated hydrocarbon is conveyed from its point of introduction to an exit therefrom while being heated to a temperature at least sufficient to decompose said halogenated hydrocarbon to form a pyrolysis gas containing halide, substantially all in the form of gaseous hydrogen halide, together with a combustible hydrocarbon gas;

introducing waste metal into said pyrolysis chamber wherein it is conveyed together with said halogenated hydrocarbon and heated to a halogenation temperature whereat at least one component of said waste metal will react with said hydrogen halide to form the corresponding metal halogenide;

directing said gaseous hydrogen halide through said pyrolysis chamber cocurrently and in contact with said waste metal while said waste metal is heated to said halogenation temperature and until substantially all of said hydrogen halide and at least a portion of said waste metal is converted into at least one metal halogenide which is vaporized under the temperature applied;

removing from said pyrolysis chamber a gas stream containing said metal halogenide and said combustible gas, and separating metal halogenide therefrom by condensation leaving a residual gas stream containing said combustible gas; and

utilizing at least a portion of said residual gas stream to provide heat to said pyrolysis chamber.

13. The process of claim 12 wherein said pyrolysis chamber is a rotary kiln.