Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B53/00—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
  • C10B53/07—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form of solid raw materials consisting of synthetic polymeric materials, e.g. tyres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
  • B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
  • B01J19/122—Incoherent waves
  • B01J19/126—Microwaves
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B19/00—Heating of coke ovens by electrical means
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10B—DESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
  • C10B53/00—Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00002—Chemical plants
  • B01J2219/00027—Process aspects
  • B01J2219/0004—Processes in series
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/18—Details relating to the spatial orientation of the reactor
  • B01J2219/187—Details relating to the spatial orientation of the reactor inclined at an angle to the horizontal or to the vertical plane
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/141—Feedstock
  • Y02P20/143—Feedstock the feedstock being recycled material, e.g. plastics

Definitions

• the present invention is concerned with the thermal treatment of carbonaceous material, such as carbonaceous waste materials.
• the heating medium itself or the product of the pyrolysis or both comprise carbon and in the treatment of scrap material on a continuous basis, the amount of carbon builds up. Normally, it is either recycled or it is treated to remove materials such as metals, and it is then disposed of to waste. In many of the known processes, the gaseous pyrolysis products are recycled or otherwise treated to maintain the energy balance and reduce the overall cost of treating the waste.
• the hot medium may be contacted directly with the heat exchange means in an non-oxidising atmosphere, or oxygen can be present in which case thermal energy is released by combustion of the hot medium.
• the medium consists essentially of carbonaceous material; the latter may consist essentially of elemental carbon, or it may be capable of being pyrolysed to elemental carbon by microwave radiation.
• the medium contains carbonaceous material as hereinbefore described admixed with a secondary material not itself susceptible to microwave heating.
• the nature of the secondary material is such that contact of the material with hot elemental carbon can yield heat from the former.
• the contact of the carbon and secondary material may merely involve heat transfer from the former to the latter; alternatively the contact may involve a chemical interaction therebetween.
• a preferred secondary material includes metal ores susceptible to reduction by hot carbon, for example zinc or aluminium ores. In this way, metals can be obtained from the process.
• the carbonaceous material typically comprises waste hydrocarbon or carbohydrate material.
• waste hydrocarbon or carbohydrate material examples include natural or synthetic rubber compounds (which may be pyrolysable to elemental carbon by microwave radiation), agricultural waste material such as citrus fruit peel, olive waste products and nut shell, non- putrescent domestic waste, toxic waste, hospital waste and halogenated hydrocarbons, or other types of organic refuse.
• the carbonaceous material should contain carbon filler.
• a particularly preferred carbonaceous material is carbon-filled vulcanised rubber, such as a waste tyre compound in chopped or finely divided form.
• the thermal treatment of the medium typically involves pyrolysis of the carbonaceous material, whereby fission of carbon-carbon bonds, and of more polar chemical bonds, yields elemental carbon which can then be fed or passed to the second treatment zone.
• the thermal treatment involves heat transfer or chemical interaction between the carbonaceous material and any secondary material not susceptible to microwave heating, such as the reduction of metal ores as hereinbefore described.
• the microwave radiation is preferably employed at such a power and for sufficient time as to effect the above described pyrolysis of the carbonaceous material, and, where appropriate, also treatment of the secondary material as described above.
• the temperature of the medium in the first zone is from about 800°C upwards.
• the microwave radiation is supplied to the first zone by means of at least one, preferably more than one, microwave generators.
• the generators may be of similar power output, or, alternatively of graduated power output (for example, of gradually increasing or decreasing power output in the downstream direction). It is preferred that the microwave generators operate at a power output in the region of 60k .
• the atmosphere of the first zone is preferably substantially oxygen-free.
• the atmosphere is reducing, typically comprising a hydrocarbon medium, or an inert gaseous medium such as nitrogen. It is preferred to use a reducing atmosphere when environmentally sensitive compounds, such as halogenated compounds and sulphur are expected in the gas products (for example when the material being treated comprises CFC's, PCB's or mercaptans). These compounds would therefore be converted to acids (HF, HC1, HBr, H2S) which can be readily scrubbed from the exhaust gases.
• the atmosphere of the first zone is se1f-perpetuating , whereby pyrolysis of the waste material during microwave radiation yields hydrogen and low molecular weight gaseous hydrocarbons from the carbonaceous material, so as to provide a reducing atmosphere in the first zone.
• the gaseous hydrocarbon products produced in thermal treatment step (a) are preferably recycled, the recycled hydrocarbon products optionally being mixed together with other air-excluding gases, such as carbon monoxide or carbon dioxide.
• the recycling is advantageous in lessening the requirement for separate supply of gaseous hydrocarbons, and is also beneficial in the following instances :
• the heat exchange means are in the second zone, so that a heat exchange fluid can be heated.
• the heat exchange fluid comprises water or air, or any other fluid which can be heated in a substantially controlled fashion. Heating water to form steam is preferred.
• exit means are provided for transfer of thermal energy generated in the method to a heat exchange apparatus or the like, where its thermal properties can be utilised to generate heat in a heating system. It is further preferred that gaseous outlet means are provided, for transfer of hot gaseous by-products to heat exchange apparatus according to the invention.
• the second zone contains an atmosphere which promotes combustion of hot elemental carbon.
• the second zone atmosphere comprises an oxygen-containing medium, the oxygen preferably being present at a level of at least about 57» by volume.
• baffle means or other gas precluding means are provided between the first and second zones for this purpose.
• the method is typically carried out in a thermally resistant housing which is preferably resistant to temperatures of up to about 1800-2000 ° C .
• the housing may typically be of fire brick-lined or refractory-lined, stainless steel or ceramic material.
• step (b) of the method involves feeding the thermally treated medium along an inclined transfer surface arranged to communicate between the first and second zones.
• the medium is allowed to flow along the inclined surface, under the influence of gravity, from the first zone to the second zone.
• the medium may be fed, typically by means of a gravity feed hopper, into the first zone, to be collected on the transfer surface.
• the first zone may comprise an inner, substantially circular chamber, in which case the second zone preferably comprises a circumferential annular chamber arranged around the inner chamber.
• the transfer surface is defined by the floor of the chambers, and typically provides a substantially conical or frustoconical surface over which the carbonaceous material can flow.
• the medium is fed to an apex region of the conical transfer surface.
• the first and second zones respectively comprise first and second chambers, arranged such that the first chamber is superjacent the second chamber.
• the carbonaceous material can sink through the first chamber, such that at least part of the treated medium is passed to the second chamber.
• the chambers in the second embodiment may be arranged remote from one another, communication between the remote chambers being provided by a conduit arranged to extend therebetween.
• the conduit may be provided with an air lock for precluding gaseous communication between the chambers .
• the superjacent first chamber may be at least partly enclosed by the second chamber, such that the treated material can be allowed to sink directly from the first chamber to the second chamber.
• apparatus for thermally treating a medium comprising a carbonaceous material which apparatus comprises:
• a housing comprising first and second zones, which zones are arranged such that at least part of the medium can flow directly from the first zone to the second zone ;
• At least one microwave radiation source arranged so as to be capable of directing microwave radiation into the first zone to thermally treat the medium;
• the parts of the apparatus according to the invention may be substantially as hereinbefore described with reference to the method according to the invention.
• the present invention further comprises a heating system, which comprises:
• One highly preferred aspect of the present invention comprises a method of thermal treatment of waste material not susceptible to microwave radiation, which comprises contacting the waste material, in a first zone under an atmosphere where flame generation is substantially prevented, with a bed of pulverulent material which comprises carbon in elemental form, or a material which is capable of being pyrolysed to elemental carbon by microwave radiation; and heating the pulverulent material by means of microwave radiation such that thermal energy is transferred to the waste material to pyrolyse it to carbon; and wherein carbon is removed from the first zone to a second zone and immediately treated to release thermal energy therefrom for recovery by a heat-exchange medium.
• carbon is formed in the first zone and thus, to prevent a build-up, some carbon is removed continuously or intermittently.
• this carbon to release thermal energy is a surprising and highly advantageous concept since the material would otherwise not be utilised to release energy.
• the energy can be released by direct heat exchange or by permitting combustion in the second zone, to release further heat .
• Figure 1 is a schematic representation of a portion of a first embodiment of apparatus according to the present invention
• Figure 2 is a schematic representation of a second embodiment of apparatus according to the present invention.
• Figure 3 is a schematic representation of a modification of the apparatus of Figure 2.
• apparatus generally designated 1 which comprises a feeder 2a and a treatment vessel 2b.
• Treatment vessel 2b comprises a reducing chamber 3 and a circumferential ly extending oxidising chamber 4.
• reducing chamber 3 comprises an inner circular zone of vessel 2b
• oxidising chamber 4 comprises a circumferential annular chamber around chamber 3.
• a plurality of microwave generators 5 are arranged relative to treatment vessel 2b so as to be capable of directing microwaves into the reducing chamber 3.
• the microwave generators 5 may all be of substantially similar power output, or alternatively, of graduated power output (for example, of gradually increasing or decreasing power in the direction of travel of material to be pyrolysed through chamber 3 as shown by arrow A).
• Transfer surface 6 is inclined so that elemental carbon present in chamber 3 can flow to oxidising chamber 4.
• Feeder 2a is arranged above chamber 3, so that any waste material contained in feeder 2a can be allowed to fall onto transfer surface 6 within chamber 3.
• Feeder 2a comprises first and second valve members 7 and 8, for controlling discharge of waste material from feeder 2a.
• Feeder 2a includes an intermediate chamber 9, in which waste material to be treated can be stored if required.
• Intermediate chamber 9 is provided with first and second vacuum pumps 10 and 11, wherein vacuum pump 10 is in gaseous communication with the external atmosphere and vacuum pump 11 is in gaseous communication with a hydrocarbon gaseous recycling system of the apparatus (the recycling system not being shown in the drawing).
• the material to be treated in apparatus 1 comprises a waste material comprising, or pyrolysable to, elemental carbon.
• feeder 2a is shown as a gravity fed mechanism, it is of course appreciated that the waste material could be fed to chamber 3 in a number of ways, such as an inclined slope feeding mechanism, a substantially horizontal feed conveyor or the like.
• Chamber 3 On arrival in chamber 3, the waste material is subjected to microwave radiation for a sufficient time and intensity so as to convert the material to a medium consisting essentially of elemental carbon.
• Chamber 3 contains an atmosphere 12 under which flame generation is substantially prevented, and typically comprises a nitrogen or hydrocarbon reducing gaseous medium.
• Atmosphere 12 is se1f-perpetuating , in that pyrolysis of the waste material during the microwave radiation, yields low molecular weight gaseous hydrocarbons from the waste material.
• chamber 3 is provided with a gas inlet for communicating at least the initial reducing atmosphere to chamber 3.
• Outlet 13 provides an exit for gaseous hydrocarbon by-products which are transmitted to condensation or distillation processing systems (not shown).
• Baffle 14 is provided to obviate gaseous communication between chambers 3 and 4.
• Chamber 4 can have a non- oxidising inert atmosphere so that mere heat exchange is effected. However, it can instead contain an oxygen-rich atmosphere 15.
• Inlet 16 is provided to communicate an oxygen rich gas to chamber 4, and outlet 17 is provided for removing hot combustion gases from chamber 4. On contact of the elemental carbon with atmosphere 15, the former combusts to yield hot gaseous products which escape chamber 4 via outlet 17.
• Outlet 17 conveys the hot gaseous products to a heat exchange apparatus or the like, where their thermal properties can be utilised to generate heat in a heating systern.
• Heat exchange apparatus (not shown) are provided in chamber 4, so that a heat exchange fluid, such as water, can be directly or indirectly heated in chamber 4 by means of the hot elemental carbon.
• apparatus generally designated 1 which comprises a feeder 2a, a reducing chamber 3 and a subjacent oxidising chamber 4.
• a microwave generating source 5 is arranged to direct microwaves along conduit 18 into reducing chamber 3.
• Conduit 18 is provided with a pressure resistant microwave window 19.
• Feeder 2a is provided with first and second vacuum pumps 10, 11 as described with reference to Figure 1.
• Outlet 13 provides an exit for gaseous hydrocarbon by- products which are transmitted to condensation or distillation apparatus.
• Conduit 20 extends between the base portion 3a of chamber 3 and the top portion 4a of chamber 4. Conduit 20 is provided with an air lock 21 for precluding gaseous communication between chambers 3 and 4.
• Chamber 4 is provided with an inlet 16 for supply of an oxygen-rich gas and outlet 17 is provided for the removal of hot combustion products from chamber 4.
• Outlet 17 conveys the hot gaseous products to heat exchange apparatus .
• the gaseous supply and temperature conditions within chamber 4 are such that a fluidised bed combustor is provided therein.
• the carbonaceous material is fed to chamber 3 and is pyrolysed to yield elemental carbon.
• the treated medium which is rich in elemental carbon, is allowed to sink through chamber 3 and conduit 20, so as to be transferred to the oxygen-rich environment of chamber 4.
• Figure 3 shows chamber 3 as comprising a receptacle 22 having an open end 23.
• Chamber 4 is arranged to circumferentially enclose the main body 24 of receptacle 22.
• the carbonaceous material is pyrolysed in receptacle 22 unfair the treated medium sinks through receptacle 22 and is passed through open end 23 to chamber 4.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Toxicology (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Health & Medical Sciences (AREA)
• Health & Medical Sciences (AREA)
• Electromagnetism (AREA)
• Processing Of Solid Wastes (AREA)
• Carbon And Carbon Compounds (AREA)
• Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
• Tunnel Furnaces (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1993
  • 1993-02-05 GB GB939302399A patent/GB9302399D0/en active Pending
• 1994
  • 1994-02-04 AU AU59754/94A patent/AU684067B2/en not_active Ceased
  • 1994-02-04 KR KR1019940002058A patent/KR940020038A/ko not_active Application Discontinuation
  • 1994-02-04 CA CA002153808A patent/CA2153808A1/en not_active Abandoned
  • 1994-02-04 SG SG1996000584A patent/SG48721A1/en unknown
  • 1994-02-04 JP JP6517780A patent/JPH09500149A/ja active Pending
  • 1994-02-04 PL PL94309696A patent/PL309696A1/xx unknown
  • 1994-02-04 GB GB9513643A patent/GB2289476B/en not_active Expired - Fee Related
  • 1994-02-04 BR BR9406342A patent/BR9406342A/pt not_active Application Discontinuation
  • 1994-02-04 MX MX9400937A patent/MX9400937A/es not_active IP Right Cessation
  • 1994-02-04 EP EP94905786A patent/EP0682685A1/de not_active Withdrawn
  • 1994-02-04 WO PCT/GB1994/000205 patent/WO1994018286A1/en active Application Filing
• 1995
  • 1995-07-04 NO NO952652A patent/NO952652D0/no unknown
  • 1995-08-01 FI FI953674A patent/FI953674A/fi unknown

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