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US 10,131,847 B2Granted
Conversion of waste plastics material to fuel
AssigneePlastic Energy Limited
InventorsDavid McNamara, Michael Murray
Life of this patent
Estimating the term…
Abstract
A process is described for treating waste plastics material to provide at least one on-specification fuel product. Plastics material is melted and then pyrolyzed in an oxygen-free atmosphere to provide pyrolysis gases. The pyrolysis gases are brought into contact with plates in a contactor vessel so that some long chain gas components condense and return to be further pyrolyzed to achieve thermal degradation. Short chain gas components exit the contactor in gaseous form and proceed to distillation to provide one or more on-specification fuel products. A pipe directly links the pyrolysis chamber to the contactor, suitable for conveying upwardly-moving pyrolysis gases and downwardly-flowing long-chain liquid for thermal degradation.
Claims26
A process for treating waste plastics material to provide at least one fuel product, the process being implemented by an apparatus comprising:
- an extruder configured to melt the waste plastics material into a molten material,
- a pyrolysis chamber configured to be isolated during purging via a purging conduit,
- a contactor configured to be isolated during the purging via the purging conduit, the contactor comprising a bank of condenser elements inside the contactor comprising plates sloped downwardly and having apertures and forming an arduous path within the contactor, and a heat exchanger including a cooling jacket surrounding at least a portion of said condenser elements, wherein the portion of said condenser elements are surrounded by the cooling jacket in a first direction when viewing the contactor and the cooling jacket in a side cross-sectional view thereof, and wherein the cooling jacket is provided outside an exterior surface of the contactor including the bank of condenser elements and the plates, and
- a pipe directly linking the pyrolysis chamber to the contactor in a second direction, the second direction perpendicular to the first direction,
- and the method comprising the steps of:
- melting, in said extruder, the waste plastics material including a mixture of pelletized, flaked or granularized waste plastics material including a mixture of different waste plastics material, the mixture including at least two waste plastics from the group consisting of polythene, polythene variants, polystyrene and polypropylene, the mixture being a dynamically variable mixture of polythene, polythene variants, polystyrene and polypropylene, to produce the molten material,
- pyrolysing the molten material received from the extruder in said pyrolysis chamber in an oxygen-free atmosphere with agitation to provide pyrolysis gases;
- conveying upwardly the pyrolysis gases from the pyrolysis chamber via said pipe into said contactor, said flow not including any other pyrolysis gases, the gases flowing up said arduous path within the contactor, in which:
- said pyrolysis gases directly contact the condenser elements in the contactor, so that some long chain gas components of said pyrolysis gases condense on said condenser elements and return directly via said pipe to said pyrolysis chamber for thermal degradation, said pipe being the only direct inlet into a vessel inside the contactor from the pyrolysis chamber, and
- cooling fluid is directed into the heat exchanger cooling jacket surrounding said condenser elements so that level of condensation on the condenser elements is controlled by control of temperature within the contactor, wherein the temperature of pyrolysis gases at an outlet of the contactor is maintained in the range of 240° C. to 280° C., and directly flowing said exit pyrolysis gases into a distillation column separated from said contactor, and distilling said pyrolysis gases in said distillation column to provide one or more fuel products,
- wherein the pyrolysis chamber and the contactor are purged in isolation from downstream components of the system after pyrolysis, and
- wherein, during the purging via the purging conduit, the pyrolysis chamber and the contactor are configured to be isolated from the extruder and any other of the downstream components of the system.
9 more elements
An apparatus for treating waste plastics material to provide at least one fuel product, the apparatus comprising:
- (a) an extruder configured to receive a mixture of pelletized, flaked or granularized waste plastics material including a mixture of different waste plastics material, the mixture including at least two waste plastics from the group consisting of polythene, polythene variants, polystyrene and polypropylene, and for melting the waste plastics material including the mixture of pelletized, flaked or granularized waste plastics material including a mixture of waste plastics material, the mixture including at least two waste plastics from the group consisting of polythene, polythene variants, polystyrene and polypropylene, the mixture being a dynamically variable mixture of polythene, polythene variants, polystyrene and polypropylene, to produce the molten material,
- (b) a plurality of pyrolysis chamber and associated contactor pairs, each pair comprising:
- (b(i)) a pyrolysis chamber for pyrolysing the molten material with agitation in an oxygen-free atmosphere to provide pyrolysis gases, the pyrolysis chamber configured to be isolated during purging via a purging conduit;
- (b(ii)) a contactor configured to be isolated during purging via the purging conduit, the contactor having
- a bank of condenser elements inside the contactor so that some long chain gas components condense on said elements,
- said condenser elements comprising a plurality of plates forming an arduous path for pyrolysis gases, said plates being sloped downwardly for run-off of condensed long-chain hydrocarbon, and including apertures to allow upward progression of pyrolysis gases, and
- a contactor jacket surrounding at least a portion of the condenser elements with cooling fluid directed into the jacket, wherein the portion of said condenser elements are surrounded by the contactor jacket in a first direction when viewing the contactor and the contactor jacket in a side cross-sectional view thereof, and wherein the contactor jacket is provided outside an exterior surface of the contactor including the bank of condenser elements and the plates, and
- a controller to control temperature of the jacket to control level of condensation,
- (b(iii)) a pipe directly linking the pyrolysis chamber to the contactor in a second direction, the second direction perpendicular to the first direction, the pipe being arranged for conveying upwardly-moving pyrolysis gases into the contactor and for conveying downwardly-flowing long-chain liquid for thermal degradation from the contactor to said chamber, said pipe being linked only with said chamber and said contactor, said pipe being the only direct inlet into a vessel inside the contactor from the pyrolysis chamber,
- (b(iv)) a contactor outlet conduit configured to allow short chain gas components to exit from the contactor in gaseous form;
- and
- (c) a distillation manifold linked with the contactor outlet conduits of said pairs,
- (d) a distillation column separated from the contactor and being linked with the manifold for distilling said pyrolysis gases from the contactor to provide one or more fuel products, and
- (e) the purging conduit adapted to purge the pyrolysis chamber and the contactor of each pair in isolation from downstream components of the apparatus, and to pump a purging gas through the pyrolysis chamber and the contactor of each pair, and
- wherein, during the purging via the purging conduit, the pyrolysis chamber and the contactor are configured to be isolated from the extruder and any other of the downstream components of the system.
12 more elements
Dependencies are inferred from the claim text.