Process for the recycling of plastics and the extraction of hydrogen thereby

Abstract

A continuous process for the pyrolysis of plastics, the process comprising a reservoir 28 of plastics material, a reservoir 26 of a FeAlOx catalyst wherein x is an integer, means for admixing 40 the c

Description

18 01 24 The present invention relates to a process for the recycling of plastics and the extraction of hydrogen thereby, in particular a practical and industrial scale process for realising an 5 efficacious process related to a known laboratory method. Background The processing of waste plastics is an ongoing societal problem and is addressed in several ways. Whilst many plastics may be recycled, such as by melting and extrusion io to form new objects, or simply by melting and compression, there can be up to 50% waste in these processes from virgin waste material as not all plastics are appropriately labelled, separable or available in sufficient quantity. In addition, plastics, such as from medical waste, require incineration and are not suitable for direct recycling. Incineration whilst obtaining heat from the plastics waste does not necessarily do so 15 efficiently or provide energy which is readily utilised elsewhere. There is therefore a need to recycle waste plastic effectively and one method of doing so is to pyrolyse plastic waste. While such methods have been widely practised most do not produce other than complex mixtures of organic molecules which require significant further separation. 20 Recent breakthroughs including Jie, X., Li, W., Slocombe, D. et al. Microwave-initiated catalytic deconstruction of plastic waste into hydrogen and high-value carbons. Nat Catal 3, 902-912 (2020). Have shown that it is possible to pyrolyse plastics to produce hydrogen and carbon, including carbon in the form of multiwalled carbon nanotubes. The production of hydrogen has inherent benefits, such as for use as a transportation 25 fuel. Multiwalled carbon nanotubes can have application but when mixed with more amorphous forms of carbon and with multilayers such material can be indistinguishable from soot or other low value carbon materials. However initial evaluation has shown that once scalable the process is not straightforward and particularly so if a commercially viable, i.e. efficient and effective, process is to be achieved. There is therefore a need for such laboratory methods to be scaled up to a practical 5 level for efficient waste processing as well as to optimise the carbon produced so that it can be an effective feedstock, whether this is simply in the form of a good quality carbon black, or more refined samples of thinner walled carbon nanotubes, any such improvements, particularly at scale will be beneficial. Relevant prior art disclosures include CN115011368A which provides a method for io producing hydrogen from low-rank coal and waste plastics and CN115432663A which provides a method and device for preparing hydrogen and multi-walled carbon nanotubes by microwave pyrolysis of waste plastics. The present invention v—* The present invention in its various aspects is as set out in the appended claims, co The present invention provides a continuous process apparatus for the pyrolysis of 1 plastics, the process apparatus comprising: a reservoir of plastics material; 20 a reservoir of a catalyst of general formula FeAIOx. wherein x is an integer; means for admixing the catalyst and the plastics material to for a mix; a first microwave furnace through which the mix is first cascaded; and configured to carry out the process such that a first, carbon solids, residue is collected and 25 a first, gaseous hydrogen, product is collected; and wherein a second microwave furnace through which the first carbon solids residue cascaded; and configured to further carry out the process such that a second, carbon solids, residue is collected and a a second, gaseous hydrogen, product is collected. 18 01 24 Detailed Description the present invention is illustrated by means of the following drawings, in which light features are provided with like numerals: Figure 1 shows a process schematic of the process of the present invention; 5 Figure 2 shows the same schematic as figure 1 in which further features are identified; Figure 3 shows detail of the first microwave Furnace of figure 1; Figure 4 shows detail of the second microwave Furnace of figure 1; and Figure 5 shows a schematic illustrating operation of a variant the microwave Furnace process of the present invention. o Looking now to the numbered features of the specific figures: Figure 1 number associations 10 - System of the present invention 5 20 - Feedstock inlet Waste Plastic (outlet pipe) 22 - Feedstock inlet of made-up Catalyst (outlet pipe) 26 - Catalyst Container (to contain made-up catalyst) 28 - Waste Plastic Container (un-pulverized unbaled plastic) o 30 - PolyGrinder® type PKM Pulveriser Grinder (PULMAN specific) 40 - Drum Mixer (powdered catalyst and powdered plastic mixer) 42 - Mixture Container (Purging could take place here using multiple containers) 25 44 - Control Ram Cavity (Please see Figure 5 Detail) 46 - Valve 18 01 24 50 - Proton Exchange Membrane (for the separation of Hydrogen from Argon) 51 - Proton Exchange Membrane (for the separation of Hydrogen from Argon) 5 52 - Proton Exchange Membrane (for the separation of Hydrogen from Argon) 60 - Nanomaterial Container Bagging (Nanomaterial end product) 62 - Nanomaterial Storage (Nanomaterial for storage, and product or for physisorption) 64 - Nanomaterial physisorption (for the production of nanomaterial batteries) io 70 - Hydrogen Gas Storage (available as a product, as an energy source for fuel cell units on the plant, and for hydrogen gas turbines, for direct back feed loop current use by the plant, and using formic acid as a hydrogen carrier for hydrogen storagesale.) 72 - Hydrogen Gas Turbine (for back feed loop current use) 15 74 - Fuel Cell Unit (for back feed loop current use) 78 - Formic Acid Hydrogen Carrier Unit (and product) 80 - Gas Coupler (for controlled gas coupling to the gas linked to the fuel cell units, the hydrogen gas turbine unit, and the formic acid hydrogen carrier unit) 20 100 - Microwave Furnace 1 (Please see Figure 5 Detail) 100a - Microwave Furnace 2 (Please see Figure 5 Detail) Figure 2 number associations 25 10 - System of the present invention 18 01 24 66 - 2 way Coupler (to direct material to, such as from storage and the reverse) 64 - Air-suspension conveyor Pipe (to maintain the integrity of the nanomaterial) 5 68 - Air-suspension conveyor Pipe 220 - Auger Pipe (from the plastic unbaling store) 222 - Auger Pipe (from the made-up catalyst store) 226 - Auger Pipe (with viewing aperture for the camera monitoring) io 230 - Auger Pipe (with viewing aperture for the camera monitoring) 240 - Offset Filler (used to offset the mound within the container for better extraction) 241 - Auger Pipe (lift to the top of mixture container) 15 242 - Auger Pipe (lift to the top of mixture container) 243 - Auger Pipe (with viewing aperture for the camera monitoring) 244 - Gravity Pipe (for gravity feed of plastic with catalyst blend) 250 - Stainless Steel Hydrogen Gas Pipe (from gas extractor) 20 252 - Stainless Steel Gas Pipe (from the gas extractor for separation at the PEM) 254 - Stainless Steel Gas-suspension Pipe (to maintain the atmosphere of 100 (first microwave furnace) and 100A (second microwave furnace) 270 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 271 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 272 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 273 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve from the hydrogen storage unit) 5 274 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 278 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 280 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 282 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) io 284 - Stainless Steel Hydrogen Gas Pipe (gas-pumped pipe through a non-return valve) 18 01 24 Figure 3 number associations 100 - First Microwave Furnace 15 44 - Control Ram Cavity (see Figure 5 Detail) 101L - RF Choke (to conform with RF regulation to mitigate the effects of HF radiation) 101U - RF Choke (to conform with RF regulation to mitigate the effects of HF radiation) 102U - Microwave Furnace 1A (4x Magnetrons in a 90-degree opposed phase angle. Please see Figure 5 Detail) 20 102L - Microwave Furnace 1B (4x Magnetrons in a 90-degree opposed phase angle. Please see Figure 5 Detail) 103 - Stainless Steel “A” Frame (forms part of the flow dynamics of the microwave tower) 104 - central irradiation section (square tower) 18 01 24 105 - Stainless Steel inverted “A" Frame (forms part of the flow dynamics of the microwave tower) 108 - Gas Extractor (comes into operation when the hydrogen is at a specific volume) 5 Figure 4 number associations 100A - Second Microwave Furnace 201L - RF Choke (to conform with RF regulation to mitigate the effects of HF radiation) 201U - RF Choke (to conform with RF regulation to mitigate the effects of HF radiation) io 202U - Microwave Furnace 2A (4x Magnetrons in a 90-degree opposed phase angle. Please see Figure 5 Detail) 202L - Microwave Furnace 2B (4x Magnetrons in a 90-degree opposed phase angie. Please see Figure 5 Detail) 203 - Stainless Steel “A” Frame (forms part of the flow dynamics of the microwave 15 tower) 204 - central irradiation section (square tower) 205 - Stainless Steel Inverted “A” Frame (forms part of the flow dynamics of the microwave tower) 208 - Gas Extractor (comes into operation when the hydrogen is at a specific volume) 20 Figures 6, 7 and 8 number associations 300 - Magnetron 310 - Servo Motor 320 - In plane of picture, i.e. lateral to falling mixture 330 - Perpendicular to plane 25 340 - Product stream servo guide 350 - Valve 360 - Waveguide Figure 8 is a key to the features of figures 6 and 7 18 01 24 18 01 24 Detailed Description The present invention will now be described with reference to the figures, in this description, numerous conduits are referred to generically as pipes for ease of reading, the specific description of those individual pipes out of context is as listed above in the 5 numerical list. The present invention provides a process for the recycling of plastics and the extraction of hydrogen, this process may also be described as a system. The process of the present invention comprises the main sections: 1. Raw material input and conditioning: this comprises feedstock inlets 20, 22 four io waste plastic and catalyst and respective storage containers 26, 28 for these raw materials. These raw materials are then conveyed further in the process for blending together. Before this the waste plastic is comminuted into small particles of size less than 8mm, more preferably of 5mm maximum dimension, more preferably size in the range of 1 to 5 mm, most preferably 2 to 4mm. These sizes provide for optimum is processing. A preferred plastic waste composition is high-density polyethylene (HOPE), polypropylene (PP), and polystyrene (PS). The catalyst composition of the present invention is an FeAIOx catalyst, such as made using the citric acid combustion method. That is by mixing iron nitrate, aluminium 20 nitrate, and citric acid at a 1:1:1 ratio. The consistency of the Catalyst will be that of a powder, once ground, burned, and dried as is the preferred preparation method, x is preferably 1 to 4. The product powder comprises carbon nanoparticles synthesised by the catalyst mediated microwave combustion of between 50-100 nm. Within this range particles 25 size is significantly influenced by the citrate / aluminium nitrate molar ratio. The process of the present invention contrasts with when the dried gels are ignited, the combustion rapidly propagates forward until all the gels are burnt completely to form a loose powder with a large amount of microscopic pores. These nanoparticles with particle sizes are typically in the range of 100-200 nm was synthesised by conventional combustion. A representative reference is Yin, Z., Li, S., Li, X., Shi, W., Liu, W., Gao, Z., Tao, M., Ma, C., &Liu, Y. (2023). A review on the synthesis of metal oxide nanomaterials by microwave induced solution combustion. RSC Advances, 13(5), 3265-3277. this shows that the HD camera will see the range between particle sizes.) 5 As the raw materials exit the conditioning stage they are monitored by cameras (feature C in the drawings). Where the material is analysed for flow rates and particle size to ensure consistency and quality. io 2. Raw material blending; this comprises a drum mixer 40 where the raw material waste plastic and catalyst are blended. A typical ratio of the blend ranges from 1:10 to 1:0.5 to 1:1 plastic to catalyst depending on the plastic type with a preferable catalyst molar ratio of 10:10:10 (Fe+AI+citric acid) to achieve max H2 yield of 55 mmol / g-plastic. Preferably the ratio changes according to the pulverised Plastic's consistency and composition and CM 15 be controlled by Al machine learning through the systematic camera viewing of the product at a point between the drum mixer and the Catalyst and the pulveriser. The tended mixture is then conveyed to a mixture container 42. At this stage the material is preferably purged with an inert gas, such as comprising or consisting of argon and / or krypton so as to displace oxygen which would otherwise give rise to 20 combustion during subsequent processing. These gasses, being of relatively large atomic diameter are preferred as they are more effectively separated from hydrogen and other process products by means of separation membranes, such as a proton membrane. For this Krtypton is especially preferred. In one embodiment two storage containers 42 are used. These are used alternately. When a storage container 42 is 25 suitably filled it is then evacuated and then merged with an inert gas, preferably argon before being used to convey material to the next stage. In the meantime, the other storage container is being used to supply the process downstream before it itself is replenished in the same process. As the raw blend exits the mixing stage they are monitored by cameras (feature C in the drawings). Where the material is analysed for 30 flow rates and particle size to ensure consistency and quality. The mixture container 42 delivers the plastics / catalyst mixture to a control ram cavity 44 which is placed at the top of the first Microwave furnace 100. The input port receives mixture from the mixture container 42 above. When the ram of the ram cavity 44 moves forward, from the delivery port to the output exhaust port, and thereby covering the input 5 port on its travel, it is configured to continue moving toward to an output exhaust port which controls the combined product volume sent through to a non-reversible port powder injector flange into the first microwave furnace as a product stream. The control ram cavity 44 comprises a gas injector to deliver Argon gas as a isolation step for the microwave furnaces 100, 100A and to replace any Argon gas processing losses. This io will be controlled by microwave furnaces using Al machine learning and sensors. 3. Pyrolysis, first stage; this utilises the Ram 44 cavity which is sequentially filled with blended raw material which has been purged and is then cascaded into the first microwave Furnace 100 where it is exposed to microwave radiation for the pyrolysis of the raw material blend to produce hydrogen and carbon products. The carbon products CM 15 leave the Furnace 100 at its base and the hydrogen and other gases in the Furnace by means of pipe 250, a gas extractor to await which comes into operation when the hydrogen is at a specific level. In the method of the present invention, Initially the interior co of the Furnace 100 and 100A will be set at 1 bar as an argon environment. During irradiation, the addition of mass will increase the interior pressure to a point when the 20 pressure within the Furnace reaches 2.45bar at which point the gas-extractor pump will be activated via a pressure sensitive switch. The actuated gas-extractor will then maintain a pressure at 2.4bar. The existing gas then continues through pipe 250 to a Proton Exchange Membrane 50 for the separation of Hydrogen from Argon. The argon or other inert gas used is then recycled to raw material mixture container42 and the 25 hydrogen which has been separated is conveyed along pipe 270. In the present invention the argon is recycled to a storage container and then used in a container 42. During irradiation some CH4, C2+ hydrocarbons, CO and CO2 are likely to be produced, this is preferably separated from the inert has, such as argon. A representative level of contamination is (CH4) 5.8 to 4.2% by mass, (C2+) 2.8 to 6.1%, (CO) 16.2 to 11.8% and 30 (CO2) 1.8 to 1.9%. The most significant is the amount of CO. The process is preferably configured to recirculate the carrier gas after proton exchange including hydrocarbon by products through one or more of the microwave furnaces, this provides further catalyst mediated pyrolysis releasing further hydrogen and improving process efficiency, the carrier gas may recirculated through each furnace and fed back from the second to the first furnace and from the first furnace to incoming mix this providing the cleanest end 5 stage and higher process efficiency. 4. Pyrolysis, second stage; the carbon products leaving Furnace 100 at its base are conveyed using pipe 254 and cascaded into the second microwave Furnace 100A where it is again exposed to microwave radiation for the pyrolysis of the carbon products (to produce hydrogen and carbon products. The carbon products leave the io Furnace 100 at its base and the hydrogen and other gases in the Furnace leave by means of pipe 250, a gas extractor to await which comes into operation when the hydrogen is at a specific level. In the process / method the ievel of the hydrogen determined by using a hydrogen gas detector and sensor combination to confirm the H2 %voi. The hydrogen ievel is a function of the amount of product flowing through the C\1 m15 Furnace 100 with additional amounts at Furnace 100A. The present process is modelled to achieve an overall figure of 77.6% vol of Hydrogen Gas over a volume of plastic feedstock throughput of high-density polyethylene (HDPE). polypropylene (PR) CO or polystyrene (PS). Therefore, to achieve the 77.6% vol the machine would need to eat approximately 10Kg x 55.6mmoles / g of plastic to produce 1.11 Kg or 13.52m3 of 20 Hydrogen The exiting gas then continues through pipe 252 to a Proton Exchange Membrane 50 for the separation of Hydrogen from Argon. The argon or other inert gas used is then recycled to raw material mixture container 42 and the hydrogen which has been separated is conveyed along pipe 270. This second pyrolysis increases the efficiency of the process to near 100%, the carbon products from the first stage of the 25 pyrolysis typically having residual and pyrolysed material and efficiencies in practical circumstances are typically in the range 91% to 92% of mass balance. The dual stage pyrolysis of the present invention provides a much-improved process by giving higher efficiency in the generation of hydrogen and the production of more pure carbon end product. 30 5. Pyrolysis Overall As described the mixture emerging from the powder injector flange falls under gravity within an Argon gas environment through feed stream guides to an irradiation reaction point 1 metre downward, where 4x inversely phased. The furnace preferably uses 5 2450MHz magnetrons. Waveguides put in place in a cross format, delivering electromagnetic power into the mixture. A second cross format magnetron arrangement isa preferably placed a further 28 centimetres below the first. Both microwave furnace cavities, of 100, 100A have inside dimensions of 28cm x 28cm x 28cm. Al machine learning controls the maximum power level by viewing the incoming mixed feedstock io entering the control ram cavity via a viewing point between the mixture container 442 and the control ram cavity. Full power is preferably in the 1 to 8kW range, preferably 4Kw to 8kW for the first furnace and in the 1 to 8kW range, preferably 4kW to 8kWfor the second irradiation reaction point. The first microwave furnace 100 and second microwave furnace 100A systems consist of a microwave generator, and controller and CM 15 are suitably choked to conform to microwave leakage regulation. Al machine learning preferably controls all magnetron phasing and ensure that each is always on and never off. The method and apparatus of the present invention preferably configured that if one co phase goes off then ail go off immediately, to protect the choke regulations and the magnetrons. Al machine learning preferably controls cooling using a closed water 20 cycle system. The second microwave furnace can replace the first microwave furnace for redundancy purposes. In operation heat is generated at the catalyst and transferred to the plastic substrate causing catalytic scission of the C-H bonds. This initial stage reaction will typically produce 97% hydrogen from the mixture in 20 seconds, typically producing 70 (HOPE), 25 60 (PP) and 80 (PS)wt.% / g plastic of carbon nanomaterials (extensively Multi-walled carbon nanotubes (MWCNT). As the catalyst and plastic mixture is irradiated, heat will generate convection within the catalyst and plastic mixture flow along with possible sputtering at the reaction points which will affect the fall rate and direction of the product stream (PS). The use of feed stream guides will restore the falling product to the upper 30 irradiation point while the lower feed stream guides will catch product for irradiation by the lower irradiation reaction point. Any catalyst and plastic mixture not irradiated will collect at the bottom of the first microwave furnace and be used for irradiation at the second microwave Furnace 100A. The hydrogen within the first microwave furnace and second microwave furnace will be extracted using a proton exchange membrane (PEM). An alternative placement is shown in Figure 6, this is more efficient as it 5 processes the gas from the two furnaces 100, 100A and provides more even gas flow as processing, particularly in stat up and shut down along with any changeover between feedstocks provides uneven hydrogen generation between the furnaces and a combined proton exchange membrane (PEM) hydrogen vs other (particularly inert gas and any carbon oxides) which provides more efficient operation and gas flow. io The second microwave furnace 100A produces hydrogen from latent structures within the carbon nanomaterial received from the first microwave furnace and will be of an exact scale and have the same features to that of the first microwave furnace, excluding the control ram cavity. The bottom of the second microwave furnace will have a control gate controlled by Al machine learning to dispense carbon for storage and for direct CM 15 bagging. Microwave furnaces of the general sort required by the present invention, though not th* specific configuration for continuous operation, as opposed to Patch wise operation as disclosed in D. Boonthum et al. / Songklanakarin J. Sci. Technol. 41 (3), 494-500, 2019, are known. 20 6. Hydrogen postprocessing; the hydrogen supply 270 from the proton exchange membrane units 50, 52 as fed by the first Furnace and the second Furnace is combined and conveyed to hydrogen gas storage 70. This hydrogen is then conveyed to gas coupler 80 for distribution, such as to the fuel cell units 74, the hydrogen gas turbine unit 25 72, and the formic acid hydrogen carrier unit 78. It may also be fed to the nanomaterial physisorption unit 64 for physisorption onto the carbon products of the first and second furnaces. Fuel cell unit 74 and the hydrogen gas turbine unit 72 are preferably used for the production of electricity to supply the overall process and in particular the magnetrons of 30 the first and second furnaces 100, 100A. The hydrogen may also be used for the production of formic acid. This is particularly useful when oxygen-containing plastics are pyrolysed as the resulting carbon dioxide is reacted with the hydrogen to form the useful by-product of formic acid and thus also avoid the production of common dioxide by the process. The present invention therefore includes a process for the pyrolysis of oxygen 5 containing plastics and plastics with catalyst, for the production of hydrogen, carbon dioxide and carbon by microwave pyrolysis within system production of formic acid. This is particularly beneficial as with certain plastics, such as polyethylene terephthalate (a widely used plastic for drinks containers) the ratio of hydrogen to oxygen means that the hydrogen created on pyrolysis is sufficient to provide the energy required for the 10 pyrolysis process as well as being sufficient to react with the carbon dioxide, thus providing a self-contained process with the added advantage of producing carbon nanomaterial as a by-product. In a further preferred embodiment of the present invention the formic acid is combined with the carbon nanomaterials to provide a substrate as an end product. This substrate is useful in the production of electric C\J 15 batteries, for example. The present invention therefore provides a self-contained t process for processing polyethylene terephthalate into an end product which is fully self-contained both in terms of product and energy consumption. This is particularly co environmentally beneficial. 7. Carbon processing; the carbon products of the pyrolysis exit the second furnace 20 100A under gravity and pipe 61 directs the material to junction 66 for direction to bagging silo 60 or to storage 64 for use in Nanomaterial physisorption unit 64 where physisorption of gases or liquids, preferably glycolic acid, occurs. The bottom of the first microwave furnace will collect carbon nanomaterial and unirradiated products, further catalytic conversion will take place while laying at the bottom 25 of the first microwave furnace due to the continued Fe / Plastic reaction taking place while laying at the bottom of the reaction tower producing even more hydrogen. The first microwave furnace will have a control gate (assists with the increase in volume of mass produced thereby increasing volumetric pressure within the Furnace 100) controlled by Al machine learning to dispense the “cooled” carbon nanomaterial for reprocessing by 30 extended electromagnetic irradiation in the second Microwave furnace 100A. 8. Furnace units Referring now to the more detailed figures of first 100 and second furnace 100A units, in operation the finish units are maintained at reduced pressure compared to the external atmosphere such that gas pressure results from minimal amounts of residual 5 inert gas (exampie argon) introduced with the raw material and the hydrogen involved. This makes for an efficient process since there is minimal requirement for separation on the hydrogen created by pyrolysis. Both Furnace units comprise an upper, funnel structure 103, 23 for directing incoming material 244, 50 past a radio frequency joke 101U. 201U, into a region irradiation point by means of upper magnetrons in the form of io a first Furnace preferably comprising 4x Magnetrons in a 90-degree opposed phase angle arrangement. The material then passes, falling under gravity through the Furnace, into a region irradiation point by means of lower magnetrons 102L, 202L preferably comprising 4x Magnetrons in a 90-degree opposed phase angle arrangement. The use of 4x Magnetrons in a 90-degree opposed phase angle arrangement is 15 particularly beneficial as this provides a maximum transmission of power so that the orientation of the recipient molecular bonds in the raw material (plastic catalyst mix) is CO not a significant determinant of power absorption. -j— Since the raw material falls under gravity from being introduced into the furnace by means of control ram cavity 44 material increases in velocity as it falls, as such for raw 20 material particles of size range of 1 to 5 mm (maximum dimension) giving a falling velocity range in the furnace which enables efficient timing of the production process in particular degree of radiation required at any given moment to satisfactorily pyrolyse the raw material. The use of the two sets of four magnetrons is beneficial as the first radiation in the first 25 Furnace serves to better integrate the catalyst with the plastic, and the second radiation in the first Furnace serves to provide extra energy to more substantially complete pyrolysis. However, as catalyst and plastic are not intermixed at a molecular level and the diffusion time during the irradiation process in short complete pyrolysis is not achieved in a failing raw material regime, it is noted that the falling raw material is 30 important as it means that separate particles are essentially present in a ‘rain’ of falling partides and therefore the particles do not aggregate, this gives a higher surface area for hydrogen evolution and the more even and less granular carbon products from the furnace. The more even and less granular carbon product is typically small in partide size (and in any case is typically comprised of nanoscale structures) and when this is 5 conveyed in pipe 50 the second furnace from the first Furnace intermixing occurs and in the second furnace randomisation of the catalyst plastic (predominantly pyrolysed at this point) brings catalyst into contact with further and pyrolyse material and the second furnace then provides essentially complete pyrolysis. After passing past the lower magnetrons the forming material passes lower radio 10 frequency joke 101L, 201L and is governed by means of lower funnel 105, 205 for conveying 50, 62 to the next stage of the process. Further detail on the furnaces, the upper Stainless Steel “A” Frame 103, 203 and the lower Stainless Steel Inverted "A” Frame 105, 205 define a central square tower 104, 204. The upper “A” Frame, central square tower, and the lower “A” Frame are welded 15 together to form a Microwave Tower (ie. First microwave furnace and second microwave furnace). Both the upper and lower “A” Frames have RF Chokes 101, 201, made to eliminate any RF leakage that may irradiate through the upper or lower “A” Frames 103, 203, 105, 205. In operation; The upper Stainless Steel “A" Frame of Microwave Tower 1 (first 20 microwave furnace) is connected to the Control Ram Cavity 44 that controls the feed volume of the catalysed plastic into the Microwave Furnace below through a flanged housing of a single powder injector. The Control Ram Cavity also manages the volume of inert (Argon) Gas within Microwave Furnace 100, 100A. The Control Ram Cavity 44 uses the length of the ram piston to first allow the incoming mixture from the Mixture 25 Container to fall in front of the ram through an input port, exiting storage 42. As the ram moves forward it covers the input port and advances to the flanged housing of a single powder injector where a separate gas injector is used to inject Argon gas into the volume in front of the ram for purging purposes. Once purged the power injector opens to allow the mixture to fall into the Central Square Tower 104, 204. The ram piston then 30 moves back to the input port and its process starts again. The expelled mixture from the Control Ram Cavity then falls under gravity into the Microwave furnace 100, 100A Argon gas atmosphere (or optionally evacuated as previously indicated) through Microwave Furnace 102U, 202U and then through Microwave Furnace 102L, 202L. Each of these Microwave Furnace units has optional Stainless Steel adjustable by using 5 fly by wire servo drives (with constant feedback) preferably controlled by the Al machine learning system. Raw material deflectors aimed to slow the mixture fall and to collect deflected mixture due to convection and splutter. In operation (= in use); each Microwave Furnace part 102U, 1021... 202U 202L produces microwave electromagnetic energy at a frequency of 2.45GHz through 4 io waveguides in a cross configuration at opposed phased angles of 90 degrees and a maximum power of 8kW per furnace part. Preferably each magnetron has a max continuous operating output power of 2kW directly into the catalysed mixture flowing at the microwave absorption point initiating the instant catalyst particle reaction within the plastic particles in contact with the catalyst. This reaction will cause the scission of the CM 15 C-H bonds and results in the rapid production of Hydrogen and Carbon Nanomaterials. Any particles not coming into contact with the Microwave furnace 1A irradiation, along with the produced Carbon Nanomaterials passes through the Microwave Furnace 1B to co be irradiated as described above to produce more Hydrogen and Carbon Nanomaterials. Each Microwave Furnace is preferably constructed using Stainless 20 Steel plates measuring 28mm x 28mm x 28mm (L x W x H) welded into place at the upper and lower “A” Frames. The Microwave Furnace part 102U. 202UI is located directly above Microwave Furnace 102L, 202L. The lower "A” Frame will house a controlled release gate below the Microwave Furnaces for the despatch of Carbon Nanomaterials and any unirradiated catalysed mixture for further processing in 25 Microwave Tower 2 (second microwave furnace). Hydrogen is extracted using a gas extractor leading to the Proton Exchange Membrane (PEM) 50, 52 to separate the Hydrogen gas from the Argon gas. This Argon gas retrieved from the Proton Exchange Membrane is then used to inject into the catalysed mixture at the Control Ram Cavity 44. Preferably both furnaces are constructed with the same dimensions and have the 30 same associated features, excluding the Control Ram Cavity. Referring now to figures 6, 7 and 8. Figure 8 provides a key to the graphicai features used in figures 6 and 7. Figures 6 and 7 show a vertical cross-section (6) and a horizontal cross-section (7) based around the centre of the central irradiation section 204. As noted this section is of rectangular cross-section, preferably square (in both 5 dimensions, i.e. cubic). The walls of the section have magnetrons 300 which are plane polarised perpendicularly to one another 320, 330, the microwave radiation emanating during operation is channelled using a waveguide 360 into the central irradiation section 204. In central irradiation section 204 are present product stream servo guides 340 actuated by servo motors to return. These product stream servo guides comprise lateral io plates through which the mixture descends, the plates being laterally adjustable so as to enable the following mixture to be guided. As seen in figure 6 the product stream servo guides are present at the top of the section 204, before the main irradiation from the magnetrons 300 and then between the magnetrons in a central positioning. The microwave radiation therefore does not primarily impinge, or at least is not directly C\J 15 directed towards these are guides 340, the guides guarding the mixture as it falls on t initial entry and then between the magnetrons. This provides improved efficiency, such as depending upon the amount of materia! descending. As can be seen, indirectly in co figure 7 the product stream servo guides are preferably placed perpendicular to one another so as to guide the mixture falling with respect to the magnetrons. Specifically, 20 the product stream servo guides enable the mixture to be channelled perpendicular to the incoming radiation. A form of the product stream servo guides is in the form of a metal plate, such as a plate angled, such as an angle of 5 to 25°) to the vertical so as to guide the mixture more centrally as it descends. This counteracts the tenancy of the mixture to diverge as the pyrolysis process generates gases. This improves process 25 efficiency by consolidating the mixture as it spreads out during pyrolysis, which would give less effective impingement of the incoming microwave radiation. Desirable properties of the servo motor are that it is in the form of a digital actuator that actuates an internal rotor a digital bit by bit so as to physically move an external object, in this diagram the product stream servo guides that facilitate the accurate direction of 30 fall of the product stream into the desired vicinity of the midpoint between the four phased incoming microwaves for irradiation. The servo motors are actuated by the Al machine learning algorithm to achieve optimal catalyst reaction at the two faces at the particles of plastic and catalyst. These features along with other features of the invention are preferably controlled using Al machine learning technology as a method. As regards Al machine learning. This technology is very good at learning from mistakes 5 is therefore beneficial to the invention as a whole. Al is one thing but incorporating machine learning, with the emissions of the machine, is the best tech at present to effectively run a system of the present invention that is prone to accidental mishaps and could potentially be extremely hazardous to personnel. This technology is preferably used to control the process from raw input to final output uses. This will include power io throughput usage, from managing the grid power, fuel cell unit power and the turbine power by constantly monitoring current flows in conjunction with product throughput to achieve max output efficiencies in consumption. This requires a multiplicity of sensors, and improves safety and quality of production. 18 01 24

Claims

1. A continuous process apparatus for the pyrolysis of plastics, the process apparatus comprising:a reservoir of piastics material;a reservoir of a catalyst of general formula FeAIOx, wherein x is an integer;means for admixing the catalyst and the plastics material to for a mix;a first microwave furnace through which the mix is first cascaded; and configured to carry out the process such thata first, carbon solids, residue coliected anda first, gaseous hydrogen, product collected; and whereina second microwave furnace through which the first carbon solids residue cascaded; and configured to further carry out the process such thata second, carbon solids, residue collected and aa second, gaseous hydrogen, product collected.

2. The process apparatus of claim 1 comprising a Proton Exchange Membrane for the separation of hydrogen over which gaseous product is passed for the separation of hydrogen in a product stream and a residual gas mixture as a recycle gas stream.

3. The process apparatus of claim 2 wherein each furnace feeds the gaseous hydrogen product to a separate Proton Exchange Membrane and the hydrogen separated is combined and fed to storage.

4. The process apparatus of claim 2 wherein each furnace gaseous hydrogen product configured to be fed to a single Proton Exchange Membrane and the hydrogen separated fed to storage.

5. The process apparatus of any preceding claim configured such that the process is conducted using an inert carrier gas atmosphere.

6. The process apparatus of claim 5 configured to recirculate the inert carrier gas after proton exchange, including hydrocarbon by products, through one or more of the microwave furnaces.

7. The process apparatus of claim 5 or claim 6 wherein the carrier gas is recirculated through each furnace and fed back from the second to the first furnace and from the first furnace to the incoming mix.

8. The process apparatus of any of claims 5 to 7 wherein the mix is purged with carrier gas before entry into the first furnace.

9. The process apparatus of claim 5 wherein the inert carrier gas comprises argon.

10. The process apparatus of claim 5 wherein the inert carrier gas comprises krypton.

11. The process apparatus of any preceding claim configured to be used with each or any of high-density polyethylene (HOPE), polypropylene (PP) and / or polystyrene(PS) as the plastics material.

12. The process apparatus of any preceding claim configured to be used with waste plastics as the plastics material.

13. A method of operating the process apparatus of any of claims 1 to 12 to pyrolyse the plastics material14. The method of claim 13 wherein the plastics material is any of high-density polyethylene (HDPE), polypropylene (PP) and / or polystyrene(PS).

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