(19)
(11)EP 2 516 592 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
13.06.2018 Bulletin 2018/24

(21)Application number: 10801706.2

(22)Date of filing:  20.12.2010
(51)International Patent Classification (IPC): 
C10G 1/10(2006.01)
C10B 53/07(2006.01)
F23G 5/02(2006.01)
F23G 5/00(2006.01)
C10B 47/18(2006.01)
F23G 7/12(2006.01)
(86)International application number:
PCT/IE2010/000077
(87)International publication number:
WO 2011/077419 (30.06.2011 Gazette  2011/26)

(54)

CONVERSION OF WASTE PLASTICS MATERIAL TO FUEL

UMWANDLUNG VON KUNSTSTOFFABFALLMATERIAL IN KRAFTSTOFF

CONVERSION DE DÉCHETS PLASTIQUES EN CARBURANT


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GR HR HU IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 22.12.2009 IE 20090971

(43)Date of publication of application:
31.10.2012 Bulletin 2012/44

(73)Proprietor: Cynar Plastics Recycling Limited
Dublin 2 (IE)

(72)Inventors:
  • McNAMARA, David
    County Laois (IE)
  • MURRAY, Michael
    County Dublin (IE)

(74)Representative: Weldon, Michael James 
John A. O'Brien & Associates
Unit 4, The Courtyard Business Centre Orchard Lane Blackrock, County Dublin, A94 NV07
Unit 4, The Courtyard Business Centre Orchard Lane Blackrock, County Dublin, A94 NV07 (IE)


(56)References cited: : 
WO-A2-2008/022790
US-A- 5 738 025
US-A- 5 731 483
US-A- 5 849 964
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Field of the Invention



    [0001] The invention relates to conversion of waste hydrocarbon material such as plastics into fuel.

    Prior Art Discussion



    [0002] GB2158089 (Suzy-Jen) describes a treatment process in which plastics is melted and heated to produce gas, the gas is condensed to provide an oily liquid, and this is fractionally distilled. WO2005/087897 (Ozmotech Pty) describes a process in which there may be multiple pyrolysis chambers. Pyrolysis gases are transferred into a catalytic converter where the molecular structure of the gaseous material is altered in structure and form WO01/05908 (Xing) describes a process in which there are first and second cracking stages with first and second catalysts. US2003/0199718 (Miller) describes an approach in which there is pyrolysis and the reactor is maintained at a temperature in the range of 450°C and 700°C. The effluent from the pyrolysis reactor is passed to a catalytic summarization de-waxing unit.

    [0003] US2009/0321317 (Widmer et al) describes a method and device for processing plastic-containing waste.

    [0004] US5738025 (Tachibana) describes a method and apparatus for thermal cracking of waste plastics.

    [0005] US5731483 (Stabel et al) describes recycling of plastics in a steam cracker.

    [0006] The invention is directed towards providing a process which more consistently produces particular grades of "on-spec" fuel, and/or with an improved yield.

    Summary of the Invention



    [0007] According to the invention, there is provided a process for treating waste plastics material as set out in claim 1.

    [0008] In one embodiment, the contactor elements comprise arrays of plates on both sides of a gas path. In one embodiment, the contactor element plates are of stainless steel.

    [0009] In one embodiment, the cooling means controls a valve linking the jacket with a flue, opening of the valve causing cooling by down-draught and closing of the valve causing heating.

    [0010] In one embodiment, the valve provides access to a flue for exhaust gases of a combustion unit of the pyrolysis chamber.

    [0011] In one embodiment, infeed to the pyrolysis chamber is controlled according to monitoring of level of molten plastics in the chamber, as detected by a gamma radiation detector arranged to emit gamma radiation through the chamber and detect the radiation on an opposed side, intensity of received radiation indicating the density of contents of the chamber.

    [0012] In one embodiment, the pyrolysis chamber is agitated by rotation of at least two helical blades arranged to rotate close to an internal surface of the pyrolysis chamber. Preferably, the pyrolysis chamber is further agitated by a central auger. In one embodiment, the auger is located so that reverse operation of it causes output of char via a char outlet.

    [0013] In one embodiment, the temperature of pyrolysis gases at an outlet of the contactor is maintained in the range of 240°C to 280°C.

    [0014] In one embodiment, a bottom section of the distillation column is maintained at a temperature in the range of 200°C to 240°C, preferably 210°C to 230°C. Preferably, the top of the distillation column is maintained at a temperature in the range of 90°C to 110°C, preferably approximately 100°C.

    [0015] In one embodiment, diesel is drawn from the distillation column and is further distilled to provide on-specification fuels.

    [0016] In one embodiment, material is drawn from the top of the distillation column to a knock-out pot which separates water, oil, and non-condensable gases, in turn feeding a gas scrubber to prepare synthetic gases for use in furnaces.

    [0017] In one embodiment, there is further distillation of some material in a vacuum distillation column. Preferably, heavy or waxy oil fractions are drawn from the bottom of the vacuum distillation column. In one embodiment, said heavy or waxy oil is recycled back to the pyrolysis chamber. In one embodiment, desired grade on-specification diesel is drawn from a middle section of the vacuum distillation column. In one embodiment, light fractions are drawn from a top section of the vacuum distillation column and are condensed.

    [0018] In one embodiment, the pyrolysis chamber and the contactor are purged in isolation from downstream components of the system. In one embodiment, a purging gas such as nitrogen is pumped through the pyrolysis chamber and the contactor and directly from the contactor to a thermal oxidizer where purging gas is burned. Preferably, any pyrolysis gases remaining at the end of a batch process are delivered from the contactor and are burned off together with the purging gas.

    [0019] In another aspect, the invention provides an apparatus for treating waste plastics material to provide at least one fuel product as set out in claim 11.

    [0020] In one embodiment, the cooling means is adapted to control a valve linking the jacket with a flue, opening of the valve causing cooling by down-draught and closing of the valve causing heating.

    [0021] In one embodiment, the valve provides access to a flue for exhaust gases of a combustion unit of the pyrolysis chamber.

    [0022] In one embodiment, the apparatus further comprises a purging means adapted to purge the pyrolysis chamber and the contactor in isolation from downstream components of the system, and to pump a purging gas through the pyrolysis chamber and the contactor and directly from the contactor to a thermal oxidizer where purging gas is burned.

    Detailed Description of the Invention



    [0023] The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:-

    Fig. 1 is a diagram showing a system of the invention for treatment of waste plastics; and

    Fig. 2 is a set of plots showing various key parameters monitored during operation of the system.


    System



    [0024] Referring to Fig. 1, a system for treatment of waste plastics comprises the following main components:

    1, two waste plastics infeed hoppers, each receiving pelletized or flaked plastics material including all polythene variants, polystyrene, and polyproplene;

    2, plastics infeed conveyor;

    3, weigh belt;

    4, extruder having four heating stages to melt the plastics material to a final temperature of about 300°C,

    5, feed lines from the extruder 4 to two pyrolysis chambers 6;

    6, pyrolysis chambers or reactors, of which there are four, each for oxygen-free pyrolysis of the hydrocarbons and delivering pyrolysis gases to a contactor 7, and each chamber 6 has a combustion unit 8 and a char outlet 9;

    7, contactor having a cooling jacket 7(a),

    10, purge lines for the pyrolysis chambers 6 and the contactors 7,

    11, flue valves for the contactors 7, linking an exhaust flue to a jacket around the contactor vessel;

    12, pipe linking each pyrolysis chamber 6 with its associated contactor 7, to allow hydrocarbon vapour (pyrolysis gases) to flow up and condensed heavy long-chain hydrocarbon material to flow back into the pyrolysis chamber 6 for thermal degradation treatment;

    13, stainless steel plates of the contactor, arranged with holes so pyrolysis gases can pass upwardly, and being sloped so that condensed long-chain hydrocarbon material runs down and back to the relevant pyrolysis chamber 6 via the pipe 12;

    15, pyrolysis gas outlet manifold for routing to distillation;

    20, first (atmospheric) distillation column;

    21, pump for diesel output of bottom of the first distillation column 20, feeding a cooler 22, in turn feeding a diesel holding tank 23 and a re-circulation link back to the distillation column 20;

    24, pump for pumping diesel fuel from the tank 23 to a heater 25, which feeds a vacuum distillation column 26;

    27, pump for pumping waxy residues to a heater 28 for re-circulation, or as a recycled feedback to the pyrolysis chambers 6 according to control by valves, not shown;

    35, pump for pumping diesel via a cooler 36 from the vacuum distillation column 26 to a diesel holding tank 37;

    38, feedback link from the diesel product tank 37 to the holding tank 23, for use if the final product diesel is determined after testing to not be at the required standard;

    40, outlet from the top of the first distillation column 20 to a light oil product tank 41;

    42, cooler for feed from the top of the vacuum distillation column 26 to a light oil tank 45;

    45, light oil tank having a link to a thermal oxidizer;

    46, pump for delivering light oil from the tank 45 to the light oil product tank 41;

    55, pump for pumping kerosene from the vacuum distillation column 26 to a kerosene product tank 60;

    70, cooler arranged to draw from the top of the first distillation column 20 to a knock-out pot 71 which separates water, oil, and non-condensable gases, in turn feeding a gas scrubber 72 to prepare synthetic gases for use in furnaces.


    Process



    [0025] Waste plastics material is processed to granular or flake form. It is heated in the extruder 4 and molten plastics is fed into the pyrolysis chambers 6. This is done while ensuring that no oxygen enters the system and molten plastics is maintained as close as possible to a pyrolysis temperature, preferably 300°C to 320°C.

    [0026] In each pyrolysis chamber 6 the plastics material is heated to 390°C to 410°C in a nitrogen-purged system while agitating. Agitation is performed by a double helical agitator with a central screw, and the helical blades sweep at a separation of about 5mm from the chamber internal surface. This maximizes heat transfer at walls of the vessel 6, which is very advantageous due to the poor heat transfer properties of the infeed plastics material.

    [0027] Pyrolysis gases rise through the direct pipe link 12 to the contactor 7. In the contactor 7 there is contact between the vapour and the metal plates 13 in a staggered baffle-like arrangement. This causes some condensation of the vapour long C chains. The proportion of gases which are condensed in this manner is approximately 15% to 20%. The level of condensation is controlled by control of the temperature of the jacket 7(a), which is cooled by chilled water and also by control of flue down-draught.

    [0028] The condensed liquid runs back through the same pipe 12 to the pyrolysis chamber 10 to be thermally degraded. The bottom of the contactor 6, as shown in the expanded view of Fig. 1, is funnel-shaped to accommodate this flow. This process is referred to in this specification as thermal degradation. It avoids need for catalytic cracking as is performed in the prior art. The thermal degradation of the invention is achieved in a very simple manner, by simply allowing the pyrolysis gases to rise through the pipe 12 into the contactor 7 and for the longer/heavier chains to condense on the baffle plates 13 and from there to run back for further pyrolysis. It is our understanding that this mechanism avoids need for catalytic cracking because the contactors 7 ensure that the heavy/long carbon chains do not pass through the system but are broken down further in the contactors or fall back into the pyrolysis vessel for further degradation. Without them, very heavy material (half way between plastic and liquid fuel) will pass through the system, giving a large proportion of syngas. The baffle plates 13 provide an arduous path with a long residence time, and their apertures allow passage of the upwardly-flowing pyrolysis gases. It is envisaged that the plates may incorporate active cooling by being part of a heat exchanger. Such cooling could be controlled to fine- tune the grade of end-product diesel obtained.

    [0029] Importantly, the thermal degradation avoids need for catalysts, which would be expensive, require replacement, and may be consumed in the process. The prior art catalyst waste material is often hazardous, resulting in expensive disposal Also, the prior processes involving catalysts are much more complicated and have tighter operating conditions.

    [0030] An advantageous aspect of the contactor operation is that the valves 11 are used to cool down the contactors by allowing down-draught from the flue into the surrounding jacket. This is in contrast to the prior catalytic cracking approach, in which efforts are made to heat the catalysts as much as possible. We have found that by providing the valves 11 with access to the flue we have a very simple and effective mechanism for cooling the contactor. The temperature control of the contactors 7 is achieved by opening and closing the flue valves 11, opening a contactor tower flue valve 11 cools the contactor due to the chimney down-draught effect. Also, cooling of the contactors takes place by controlling water flow through water pipes running through the contactor jackets 7(a)..

    [0031] The vapour at 250°C to 300°C and most preferably at 260°C to 280°C is fed into the first distillation column 20. The sump at the bottom of the column 20 has re-circulation through the pump 21 and the cooler 22 and the temperature is maintained as close as possible to 220°C in this part of the column 20.

    [0032] By appropriate operation of valves, diesel is drawn from the sump of the column 20 into the tank 23 and from there to the vacuum distillation column 26. On-spec diesel is provided from the vacuum distillation column 26 to the product tank 37.

    [0033] The vacuum distillation column 26 allows operation at much lower temperatures and is smaller, while achieving equivalent results to an atmospheric distillation column.

    [0034] The top part of the first distillation column 20 is maintained as close as possible to 100°C. Light oil is drawn directly to the tank 41. This is a by-product, but may be used to power a low-compression engine to power the plant or to generate electrical power for the grid.

    [0035] There is also a feed of light oil to the tank 41 from the top of the vacuum distillation column 26 via the tank 45 and the pump 46. It has been found that the first distillation column 20 has about 20% light oil output and the vacuum column 26 has about 10% light oil output.

    [0036] The gas scrubber 72 washes and prepares the synthetic gases for use in the furnaces for the pyrolysis chamber (process is parasitic), and waste water is delivered for treatment.

    [0037] Diesel is drawn from the bottom section of the first distillation column 20 to the holding tank 23 from which it is fed via the heater 25 to the vacuum tower 26. Heavy oil is drawn from the bottom section of the vacuum tower 26 and is used as a supply for the pyrolysis chambers, suitably heated by the wax heater 28. The main product, diesel, is drawn from the middle section of the vacuum column 26 via the cooler 36 to the product tank 37.

    [0038] Regarding the components 70, 71, and 72 linked with the top of the first distillation column 20, synthetic gases are taken off the top of the column 20. The cooler 70 draws from the top of the column 20 to the knock-out pot 71, which separates water, oil, and non-condensable gases, in turn feeding a gas scrubber 72 to prepare synthetic gases for use in furnaces. There is feedback from the knock-out pot 71 to the top of the column 20. Levels are automatically controlled.

    [0039] As a batch ends, increased load on the pyrolysis chamber agitator indicates that char drying is taking place, and that the process is ending. Rather than purge the full system with N2, risking the N2 carrying char through the full system, N2 is purged via the conduits 10 through the contactors 7 and the pyrolysis chambers 6 only. Resulting vapour is drawn off from above the contactors 7 and is burned off in a thermal oxidizer. This allows the system to continue without being distorted and isolates mechanical removal of the char. The pyrolysis chambers 6 are purged with nitrogen which passes up through the contactor 6 and out the top directly to thermal oxidisers to flush any remaining hydrocarbons. This ensures a safe char removal sequence. During this phase the pyrolysis vessel 6 and contactor 7 have been isolated from the rest of the system. This reduces process time and prevents char from being carried through the system and fouling components such as the fuel lines and pumps. It has been found that this provides improved stability in the process by avoiding risk of contamination of downstream components with char particles. It also reduces the purging time.

    [0040] The double helical agitator blades are operated in reverse to remove char during purging. This char removal process can be performed continuously, if desired.

    [0041] The char leaves the pot by opening a large valve at the base of the pyrolysis vessel 6. Under the pyrolysis vessel is a negatively charged pot which initially draws the char into it. The agitator is designed at the base such that when it operates in the reverse direction to that during processing it sweeps the char into the centre of the vessel and the agitator screw pushes the char down into a char pot. Once cooled, the char is vacuumed into a char vessel for removal from site.

    [0042] The pyrolysis chamber jacket is heated to c. 590°C so that there is further drying of the char for about 4 hours.

    [0043] Although not illustrated, each pyrolysis chamber 6 has a detector for determining content of the chamber for control purposes. The detector comprises a gamma radiation source on one side and a receiver along the opposed side. The intensity of radiation detection on the receiving side provides an indication of level in the chamber 6. A major advantage is that the emitter and the receiver are mounted on the outside of the chamber 6, and so are totally non-invasive. The emitted gamma radiation is attenuated as it passes through the chamber 6, the intensity detected at the receiver being an indication of the density of contents of the chamber 6.

    [0044] Referring to Fig. 2 various parameters for the system are monitored for effective system control. It shows that as the agitator load increases (in this example at about 14.30 hours) when char drying is taking place. It also shows that the bottom of the first distillation column 20 stays approximately constant, even between batches, due to operation of a heater.

    [0045] It will also be appreciated that the contactor 7 outlet temperature can rise above optimum towards the end of the batch.

    [0046] It has been found that the process as described above provides a high quality diesel product in the tank 37, meeting the EN590 European standards. The other major on-spec fuel is BS2869 for kerosene.

    [0047] The invention is not limited to the embodiments described but may be varied in construction and detail. For example, there may be a cooler at the contactor 7 outlet to maintain a vapour outlet temperature in the desired range. Also, there may be additional active cooling of the contactors 7, such as by chilled water circulation in a jacket around the contactor plates, or indeed by an arrangement in which the contactor has an active heat exchanger in direct contact with the pyrolysis gases. Such a heat exchanger may replace some or all of the baffle plates described above. This cooler may for example work with oil which is passed through the cooler at the target temperature. Chilled water may be used to control the oil temperature. The cooling system may also include a liquid knockout pot for return of heavier chains to the pyrolysis chambers 6 for further cracking. It has been found that maintenance of the vapour temperature at this level at the outlet of the contactor 7 is particularly advantageous for achieving the desired grade of fuel products.


    Claims

    1. A process for treating waste plastics material to provide at least one fuel product, the process comprising the steps of:

    melting (4) the waste plastics material,

    pyrolysing (6), in a pyrolysis chamber, the molten material in an oxygen-free atmosphere with agitation to provide pyrolysis gases;

    bringing the pyrolysis gases from the pyrolysis chamber into a contactor (7) having a bank of contactor elements (13) so that some long chain gas components condense on said elements,

    returning (12) said condensed long-chain material from the contactor to the pyrolysis chamber to be further pyrolysed to achieve thermal degradation, and allowing short chain gas components to exit from the contactor (7) in gaseous form; and

    distilling (20, 26) said pyrolysis gases from the contactor in a distillation column to provide one or more fuel products,

    wherein:

    the condenser elements (13) comprise a plurality of plates forming an arduous path for the pyrolysis gases in the contactor; and wherein the plates (13) are sloped downwardly for run-off of condensed long-chain hydrocarbons, and include apertures to allow upward progression of pyrolysis gases,

    wherein the contactor is actively cooled by a contactor jacket and cooling fluid is directed into the jacket, in which level of condensation is controlled by control of temperature of the jacket, and

    wherein there is a pipe directly linking the pyrolysis chamber to the contactor, the pipe conveying upwardly-moving pyrolysis gases and downwardly-flowing long-chain liquid for thermal degradation.


     
    2. A process as claimed in claim 1, wherein the contactor elements comprise arrays of plates (13) on both sides of a gas path.
     
    3. A process as claimed in claims 1 or 2, wherein the cooling means controls a valve (11) linking the jacket (7(a)) with a flue, opening of the valve causing cooling by down-draught and closing of the valve causing heating; and wherein the valve (11) provides access to a flue for exhaust gases of a combustion unit of the pyrolysis chamber (6).
     
    4. A process as claimed in any preceding claim, wherein infeed to the pyrolysis chamber (6) is controlled according to monitoring of level of molten plastics in the chamber, as detected by a gamma radiation detector arranged to emit gamma radiation through the chamber and detect the radiation on an opposed side, intensity of received radiation indicating the density of contents of the chamber.
     
    5. A process as claimed in any preceding claim wherein the pyrolysis chamber (6) is agitated by rotation of at least two helical blades arranged to rotate close to an internal surface of the pyrolysis chamber; and wherein the pyrolysis chamber (6) is further agitated by a central auger; and wherein the auger is located so that reverse operation of it causes output of char via a char outlet.
     
    6. A process as claimed in any preceding claim, wherein the temperature of pyrolysis gases at an outlet of the contactor is maintained in the range of 240°C to 280°C.
     
    7. A process as claimed in any preceding claim, wherein a bottom section of the distillation column (20) is maintained at a temperature in the range of 200°C to 240°C, preferably 210°C to 230°C; and wherein the top of the distillation column (20) is maintained at a temperature in the range of 90°C to 110°C, preferably approximately 100°C.
     
    8. A process as claimed in any preceding claim, wherein diesel is drawn from the distillation column and is further distilled (26) to provide on-specification fuels; and herein material is drawn from the top of the distillation column (20) to a knock-out pot (71) which separates water, oil, and non-condensable gases, in turn feeding a gas scrubber to prepare synthetic gases for use in furnaces.
     
    9. A process as claimed in any preceding claim, comprising further distillation (26) of some material is in a vacuum distillation column; and wherein heavy or waxy oil fractions are drawn from the bottom of the vacuum distillation column (26); and wherein said heavy or waxy oil is recycled back to the pyrolysis chamber (6); and wherein desired grade on-specification diesel is drawn from a middle section of the vacuum distillation column (26); and wherein light fractions are drawn from a top section of the vacuum distillation column (26) and are condensed.
     
    10. A process as claimed in any preceding claim, wherein the pyrolysis chamber (6) and the contactor (7) are purged in isolation from downstream components of the system wherein a purging gas such as nitrogen is pumped through the pyrolysis chamber (6) and the contactor (7) and directly from the contactor to a thermal oxidizer where purging gas is burned; and wherein any pyrolysis gases remaining at the end of a batch process are delivered from the contactor and are burned off together with the purging gas.
     
    11. An apparatus for treating waste plastics material to provide at least one fuel product, the apparatus comprising:

    means (4) for melting the waste plastics material,

    a pyrolysis chamber (6) for pyrolysing the molten material with agitation in an oxygen-free atmosphere to provide pyrolysis gases;

    a contactor (7) having a bank of contactor elements (13) so that some long chain gas components condense on said elements, wherein the condenser elements (13) comprise a plurality of plates forming an arduous path for the pyrolysis gases in the contactor, the plates (13) being sloped downwardly for run-off of condensed long-chain hydrocarbons, and include apertures to allow upward progression of pyrolysis gases;

    a pipe (12) directly linking the pyrolysis chamber (6) to the contactor (7), the pipe being arranged for conveying upwardly-moving pyrolysis gases and downwardly-flowing long-chain liquid for thermal degradation;

    a conduit (15) for allowing short chain gas components to exit from the contactor in gaseous form; and

    a distillation column (20) for distilling said pyrolysis gases from the contactor to provide one or more fuel products; and

    a cooling means including a contactor jacket for actively cooling the contactor and a controller for controlling level of condensation in said contactor by controlling temperature of the jacket.


     
    12. An apparatus as claimed in claim 11, wherein the cooling means (11, 7(a)) is adapted to control a valve (11) linking the jacket with a flue, opening of the valve causing cooling by down-draught and closing of the valve causing heating; wherein the valve (11) provides access to a flue for exhaust gases of a combustion unit of the pyrolysis chamber; and further comprising a purging means (10) adapted to purge the pyrolysis chamber (6) and the contactor (7) in isolation from downstream components of the system, and to pump a purging gas through the pyrolysis chamber and the contactor and directly from the contactor to a thermal oxidizer where purging gas is burned.
     


    Ansprüche

    1. Verfahren zum Aufbereiten von Kunststoffabfallmaterial, um mindestens ein Kraftstoffprodukt bereitzustellen, wobei das Verfahren folgende Schritte umfasst:

    Schmelzen (4) des Kunststoffabfallmaterials,

    Pyrolysieren (6) des geschmolzenen Materials unter Rühren in einer sauerstofffreien Atmosphäre in einer Pyrolysekammer, um Pyrolysegase bereitzustellen;

    Bringen der Pyrolysegase von der Pyrolysekammer in einen Extraktor (7) mit einer Bank von Extraktorelementen (13), so dass einige langkettige Gaskomponenten an den Elementen kondensieren,

    Zurückführen (12) des kondensierten langkettigen Materials von dem Extraktor zu der Pyrolysekammer, um weiter pyrolysiert zu werden, um die thermische Zersetzung zu erreichen, und Austretenlassen von kurzkettigen Gaskomponenten aus dem Extraktor (7) in Gasform; und

    Destillieren (20, 26) der Pyrolysegase aus dem Extraktor in einer Destillationskolonne, um ein oder mehrere Kraftstoffprodukte bereitzustellen,

    wobei:

    die Kondensatorelemente (13) eine Mehrzahl von Platten umfassen, die einen steilen Pfad für die Pyrolysegase in dem Extraktor bilden; und wobei die Platten (13) zum Ablaufen kondensierter langkettiger Kohlenwasserstoffe nach unten geneigt sind und Öffnungen enthalten, um die aufsteigende Fortbewegung von Pyrolysegasen zu ermöglichen,

    wobei der Extraktor durch einen Extraktormantel aktiv gekühlt wird und Kühlfluid in den Mantel geleitet wird, in dem der Grad der Kondensation durch Steuern der Temperatur des Mantels gesteuert wird, und

    wobei eine Rohrleitung vorhanden ist, die die Pyrolysekammer direkt mit dem Extraktor verbindet, wobei die Rohrleitung sich aufwärts bewegende Pyrolysegase und abwärts fließende langkettige Flüssigkeit zwecks thermischer Zersetzung befördert.


     
    2. Verfahren nach Anspruch 1, wobei die Extraktorelemente Anordnungen von Platten (13) auf beiden Seiten des Gaspfades umfassen.
     
    3. Verfahren nach Anspruch 1 oder 2, wobei das Kühlmittel ein Ventil (11) steuert, das den Mantel (7(a)) mit einem Abzug verbindet, wobei Öffnen des Ventils ein Kühlen durch Luftzug nach unten bewirkt und Schließen des Ventils ein Heizen bewirkt; und wobei das Ventil (11) Zugang zu einem Abzug für Abgase einer Verbrennungseinheit der Pyrolysekammer (6) bereitstellt.
     
    4. Verfahren nach einem der vorhergehenden Ansprüche, wobei die Speisung der Pyrolysekammer (6) gemäß einem Überwachen des Füllstandes von geschmolzenem Kunststoff in der Kammer gesteuert wird, der von einem Gammastrahlendetektor detektiert wird, der dafür angeordnet ist, Gammastrahlung durch die Kammer auszusenden und die Strahlung an einer gegenüberliegenden Seite zu detektieren, wobei die Intensität der empfangenen Strahlung die Dichte des Inhalts der Kammer angibt.
     
    5. Verfahren nach einem der vorhergehenden Ansprüche, wobei die Pyrolysekammer (6) durch Drehung von mindestens zwei spiralförmigen Blättern gerührt wird, die dafür angeordnet sind, sich nahe einer Innenoberfläche der Pyrolysekammer zu drehen; und wobei die Pyrolysekammer (6) ferner durch eine mittige Schnecke gerührt wird; wobei die Schnecke derart positioniert ist, dass ein Umkehrbetrieb derselben die Ausgabe von Teer über eine Teerausgabe bewirkt.
     
    6. Verfahren nach einem der vorhergehenden Ansprüche, wobei die Temperatur von Pyrolysegasen an einem Auslass des Extraktors im Bereich von 240 °C bis 280 °C gehalten wird.
     
    7. Verfahren nach einem der vorhergehenden Ansprüche, wobei ein unterer Abschnitt der Destillationskolonne (20) bei einer Temperatur im Bereich von 200 °C bis 240 °C, vorzugsweise 210 °C bis 230 °C, gehalten wird; und wobei das obere Ende der Destillationskolonne (20) bei einer Temperatur im Bereich von 90 °C bis 110 °C, vorzugsweise bei etwa 100 °C, gehalten wird.
     
    8. Verfahren nach einem der vorhergehenden Ansprüche, wobei Diesel aus der Destillationskolonne abgezogen und weiter destilliert (26) wird, um spezifikationsgemäße Kraftstoffe bereitzustellen; und hierin Material aus dem oberen Ende der Destillationskolonne (20) zu einem Flüssigkeitsabscheider (71) abgezogen wird, der Wasser, Öl und nicht-kondensierbare Gase trennt und wiederum einen Gaswäscher speist, um Synthesegase zur Verwendung in Brennöfen herzustellen.
     
    9. Verfahren nach einem der vorhergehenden Ansprüche, ferner eine Destillation (26) eines Teils des Materials in einer Vakuum-Destillationskolonne umfassend; und wobei schwere oder wachsartige Ölfraktionen aus dem unteren Ende der Vakuum-Destillationskolonne (26) abgezogen werden; und wobei das schwere oder wachsartige Öl in die Pyrolysekammer (6) zurückgeführt wird; und wobei spezifikationsgemäßer Diesel der gewünschten Güte aus einem mittleren Abschnitt der Vakuum-Destillationskolonne (26) abgezogen wird; und wobei leichte Fraktionen von einem oberen Abschnitt der Vakuum-Destillationskolonne (26) abgezogen und kondensiert werden.
     
    10. Verfahren nach einem der vorhergehenden Ansprüche, wobei die Pyrolysekammer (6) und der Extraktor (7) isoliert von prozessabwärtigen Komponenten des Systems gespült werden, wobei ein Spülgas wie etwa Stickstoff durch die Pyrolysekammer (6) und den Extraktor (7) und direkt von dem Extraktor zu einer thermischen Oxidationsanlage gepumpt wird, wo Spülgas verbrannt wird; und wobei Pyrolysegase, die am Ende eines chargenweisen Verfahrens übrig bleiben, von dem Extraktor aus zugeführt und zusammen mit dem Spülgas abgebrannt werden.
     
    11. Vorrichtung zum Aufbereiten von Kunststoffabfallmaterial, um mindestens ein Kraftstoffprodukt bereitzustellen, wobei die Vorrichtung Folgendes umfasst:

    Mittel (4) zum Schmelzen des Kunststoffabfallmaterials,

    eine Pyrolysekammer (6) zum Pyrolysieren des geschmolzenen Materials unter Rühren in einer sauerstofffreien Atmosphäre, um Pyrolysegase bereitzustellen;

    einen Extraktor (7) mit einer Bank von Extraktorelementen (13), so dass einige langkettige Gaskomponenten an den Elementen kondensieren, wobei die Kondensatorelemente (13) eine Mehrzahl von Platten umfassen, die einen steilen Pfad für die Pyrolysegase in dem Extraktor bilden, wobei die Platten (13) zum Ablaufen kondensierter langkettiger Kohlenwasserstoffe nach unten geneigt sind und Öffnungen enthalten, um die aufsteigende Fortbewegung von Pyrolysegasen zu ermöglichen;

    eine Rohrleitung (12), die die Pyrolysekammer (6) direkt mit dem Extraktor (7) verbindet, wobei die Rohrleitung zum Befördern sich aufwärts bewegender Pyrolysegase und abwärts fließender langkettiger Flüssigkeit zwecks thermischer Zersetzung angeordnet ist;

    eine Leitung (15) zum Austretenlassen von kurzkettigen Gaskomponenten aus dem Extraktor in Gasform; und

    eine Destillationskolonne (20) zum Destillieren der Pyrolysegase aus dem Extraktor, um ein oder mehrere Kraftstoffprodukte bereitzustellen; und

    ein Kühlmittel, das einen Extraktormantel enthält, zum aktiven Kühlen des Extraktors und

    eine Steuerung zum Steuern des Grades der Kondensation in dem Extraktor durch Steuern der Temperatur des Mantels.


     
    12. Vorrichtung nach Anspruch 11, wobei das Kühlmittel (11, 7(a)) dafür eingerichtet ist, ein Ventil (11) zu steuern, das den Mantel mit einem Abzug verbindet, wobei Öffnen des Ventils ein Kühlen durch Luftzug nach unten bewirkt und Schließen des Ventils ein Heizen bewirkt; wobei das Ventil (11) Zugang zu einem Abzug für Abgase einer Verbrennungseinheit der Pyrolysekammer bereitstellt;
    und ferner ein Spülmittel (10) umfassend, das dafür eingerichtet ist, die Pyrolysekammer (6) und den Extraktor (7) isoliert von prozessabwärtigen Komponenten des Systems zu spülen und ein Spülgas durch die Pyrolysekammer und den Extraktor und direkt von dem Extraktor zu einer thermischen Oxidationsvorrichtung zu pumpen, wo Spülgas verbrannt wird.
     


    Revendications

    1. Un procédé de traitement de déchets de matières plastiques pour fournir au moins un produit combustible, le procédé comprenant les étapes consistant à :

    faire fondre (4) les déchets de matières plastiques,

    pyrolyser (6), dans une chambre de pyrolyse, les matières fondues dans une atmosphère exempte d'oxygène avec brassage pour fournir des gaz de pyrolyse ;

    acheminer les gaz de pyrolyse de la chambre de pyrolyse à un contacteur (7) doté d'une rangée d'éléments de contacteur (13) de manière à ce que des composants de gaz à chaîne longue se condensent sur lesdits éléments,

    renvoyer (12) lesdites matières à chaîne longue condensées du contacteur à la chambre de pyrolyse pour être pyrolysés à nouveau afin d'obtenir une dégradation thermique, et permettre à des composants de gaz à chaîne courte de sortir du contacteur (7) sous forme gazeuse ; et

    distiller (20, 26) lesdits gaz de pyrolyse venant du contacteur dans une colonne de distillation pour fournir un ou plusieurs produits combustibles,

    dans lequel :

    les éléments du condenseur (13) comprennent une pluralité de plaques formant un chemin ardu pour les gaz de pyrolyse dans le contacteur ; et les plaques (13) étant inclinées vers le bas pour l'écoulement des hydrocarbures à chaîne longue condensés et comprenant des ouvertures pour permettre la progression vers le haut des gaz de pyrolyse,

    dans lequel le contacteur est refroidi activement par une enveloppe de contacteur et un liquide de refroidissement est dirigé à l'intérieur de l'enveloppe, dans laquelle le niveau de condensation est contrôlé par le contrôle de la température de l'enveloppe ; et

    dans lequel il est prévu un tuyau reliant directement la chambre de pyrolyse au contacteur, le tuyau transportant des gaz de pyrolyse se déplaçant vers le haut et un liquide à chaîne longue s'écoulant vers le bas pour dégradation thermique.


     
    2. Un procédé conforme à la revendication 1, dans lequel les éléments du contacteur comprennent des groupements de plaques (13) sur les deux côtés d'un chemin de gaz.
     
    3. Un procédé conforme à la revendication 1 ou 2, dans lequel le moyen de refroidissement contrôle une valve (11) reliant l'enveloppe (7(a)) à un conduit, l'ouverture de la valve causant un refroidissement par courant descendant et la fermeture de la valve causant un réchauffement ; et dans lequel la valve (11) fournit l'accès à un conduit pour les gaz d'échappement d'une unité de combustion de la chambre de pyrolyse (6).
     
    4. Un procédé conforme à n'importe laquelle des revendications précédentes, dans lequel l'alimentation de la chambre de pyrolyse (6) est contrôlée en fonction de la surveillance du niveau de plastique fondu dans la chambre, tel que détecté par un détecteur à rayonnement gamma disposé pour émettre un rayonnement gamma à travers la chambre et détecter le rayonnement sur un côté opposé, l'intensité du rayonnement reçu indiquant la densité du contenu de la chambre.
     
    5. Un procédé conforme à n'importe laquelle des revendications précédentes, dans lequel la chambre de pyrolyse (6) est brassée par la rotation d'au moins deux lames hélicoïdales disposées pour tourner près d'une surface interne de la chambre de pyrolyse ; et dans lequel la chambre de pyrolyse (6) est brassée en sus par une vis sans fin centrale ; et dans lequel la vis sans fin est située de manière à ce que le fonctionnement inversé de celle-ci cause l'émission de charbon via une sortie de charbon.
     
    6. Un procédé conforme à n'importe laquelle des revendications précédentes, dans lequel la température des gaz de pyrolyse à une sortie du contacteur est maintenue dans la gamme de 240 °C à 280 °C
     
    7. Un procédé conforme à n'importe laquelle des revendications précédentes, dans lequel une section de fond de la colonne de distillation (20) est maintenue à une température dans la gamme de 200 °C à 240 °C, de préférence de 210 °C à 230 °C ; et dans lequel le haut de la colonne de distillation (20) est maintenu à une température dans la gamme de 90 °C à 110 °C, de préférence d'environ 100 °C.
     
    8. Un procédé conforme à n'importe laquelle des revendications précédentes, dans lequel du diesel est tiré de la colonne de distillation et est distillé à nouveau (26) pour fournir des combustibles sur spécification ; et dans lequel des matières sont tirées du haut de la colonne de distillation (20) dans un ballon séparateur (71) qui sépare l'eau, le pétrole et les gaz non condensables, et alimente à son tour un laveur de gaz pour préparer les gaz synthétiques à l'utilisation dans les fours.
     
    9. Un procédé conforme à n'importe laquelle des revendications précédentes, comprenant la distillation supplémentaire (26) de certaines matières dans une colonne de distillation sous vide ; et dans lequel les fractions de pétrole lourd ou cireux sont tirées du fond de la colonne de distillation sous vide (26) ; et dans lequel ledit pétrole lourd ou cireux est recyclé à nouveau dans la chambre de pyrolyse (6) ; et dans lequel du diesel sur spécification de qualité souhaitée est tiré d'une section médiane de la colonne de distillation sous vide (26) ; et dans lequel des fractions légères sont tirées d'une section du haut de la colonne de distillation sous vide (26) et sont condensées.
     
    10. Un procédé conforme à n'importe laquelle des revendications précédentes, dans lequel la chambre de pyrolyse (6) et le contacteur (7) sont purgés en isolation des composants d'aval du système, dans lequel un gaz de purge tel que l'azote est pompé à travers la chambre de pyrolyse (6) et le contacteur (7) et directement depuis le contacteur jusqu'à un dispositif d'oxydation thermique où le gaz de purge est brûlé ; et dans lequel tous les gaz de pyrolyse restant à la fin d'un processus par lots sont acheminés depuis le contacteur et brûlés ensemble avec le gaz de purge.
     
    11. Un appareil de traitement de déchets de matières plastiques pour fournir au moins un produit combustible, l'appareil comprenant :

    un moyen (4) de faire fondre les déchets de matières plastiques,

    une chambre de pyrolyse (6) pour pyrolyser les matières fondues avec brassage dans une atmosphère exempte d'oxygène pour fournir des gaz de pyrolyse ;

    un contacteur (7) doté d'une rangée d'éléments de contacteur (13) de manière à ce que des composants de gaz à chaîne longue se condensent sur lesdits éléments, les éléments du condenseur (13) comprenant une pluralité de plaques formant un chemin ardu pour les gaz de pyrolyse dans le contacteur, les plaques (13) étant inclinées vers le bas pour l'écoulement des hydrocarbures à chaîne longue condensés, et comprenant des ouvertures pour permettre la progression vers le haut des gaz de pyrolyse ;

    un tuyau (12) reliant directement la chambre de pyrolyse (6) au contacteur (7), le tuyau étant disposé pour transporter des gaz de pyrolyse se déplaçant vers le haut et un liquide à chaîne longue s'écoulant vers le bas pour dégradation thermique ;

    une conduite (15) pour permettre aux composants gazeux à chaîne courte de sortir du contacteur sous forme gazeuse ; et

    une colonne de distillation (20) pour distiller lesdits gaz de pyrolyse venant du contacteur afin de produire un ou plusieurs produits combustibles ; et

    un moyen de refroidissement comportant une enveloppe de contacteur pour refroidir activement le contacteur et un contrôleur pour contrôler le niveau de condensation dans ledit contacteur en contrôlant la température de l'enveloppe.


     
    12. Un appareil conforme à la revendication 11, dans lequel le moyen de refroidissement (11, 7(a)) est apte à contrôler une valve (11) reliant l'enveloppe à un conduit, l'ouverture de la valve causant un refroidissement par courant descendant et la fermeture de la valve causant un réchauffement ; dans lequel la valve (11) fournit l'accès à un conduit pour les gaz d'échappement d'une unité de combustion de la chambre de pyrolyse ; et comprenant en sus un moyen de purge (10) apte à purger la chambre de pyrolyse (6) et le contacteur (7) en isolation des composants en aval du système, et à pomper un gaz de purge à travers la chambre de pyrolyse et le contacteur et directement depuis le contacteur à un dispositif d'oxydation thermique où le gaz de purge est brûlé.
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description