WO2018170543A1

WO2018170543A1 - System for the production of hydrogen and graphitic carbon

Info

Publication number: WO2018170543A1
Application number: PCT/AU2018/050254
Authority: WO
Inventors: Andrew Cornejo
Original assignee: Hazer Group Limited
Priority date: 2017-03-20
Filing date: 2018-03-20
Publication date: 2018-09-27

Abstract

A system for the conversion of a hydrocarbon feedstock to hydrogen gas and graphitic carbon, the system comprising one or more reactors adapted to contact at a temperature between 600 °C and 1000 °C an iron oxide catalyst with the hydrocarbon feedstock to produce one or more mixed phase streams containing hydrogen gas and graphitic carbon and one or more solid/gas separators adapted to separate at least a portion of the one or more mixed phase streams of the one or more reactors into one or more gas streams comprising hydrogen gas and one or more solid streams comprising graphitic carbon.

Description

SYSTEM FOR THE PRODUCTION OF HYDROGEN AND GRAPHITIC CARBON

TECHNICAL FIELD

[0001 ] The present invention provides a system for the production of hydrogen and graphitic carbon. More particularly, the system of the present invention is adapted to catalytically convert a hydrocarbon feedstock to hydrogen gas and graphitic carbon.

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] The underlying reaction behind the catalytic conversion of the hydrocarbon feedstock to hydrogen gas and graphitic carbon is called Thermo-Catalytic Methane Decomposition (TCMD), which decomposes methane, or other gaseous hydrocarbons, into hydrogen gas and solid carbon, according to the following formula:

CH₄(g) <→ 2H₂₍g) + C(s) ΔΗ(298°Κ) = 74.9kJ/mol (CH₄).

[0004] In the absence of a catalyst, this mildly endothermic reaction requires very high temperatures (>1200 °C) for complete methane decomposition, with the carbon being deposited as disordered amorphous carbon. The introduction of a catalyst lowers the activation energy required for this reaction considerably and also promotes the production of graphite, which has a higher market demand than amorphous carbon.

[0005] The main issue with using a catalyst in this process is the high costs involved in recovering the solid catalyst from the solid carbon product.

[0006] Historically, catalysts that have been researched for this reaction have been complex supported catalysts that are too expensive to be left as an impurity in the graphite product. The catalysts are synthesised by loading nano-sized catalytic species (such as Ni, Fe, Pb, Co, etc) onto inert catalyst supports (such as Al₂0₃, Si0₂, zeolites, etc). The inert catalyst supports assist in keeping the catalytic elements from

agglomerating into larger particles (small catalyst particles have higher active catalytic surface area and therefore higher product yields). However, despite high product yields, these catalysts need to be recovered from the graphite product and reused due to their relatively high cost of manufacture. This need to recover the catalyst adds an expensive stage to the process and degrades the graphite quality, lowering the economic potential of this process.

SUMMARY OF INVENTION

[0007] In accordance with a first aspect of the present invention, there is provided a system for the conversion of a hydrocarbon feedstock to hydrogen gas and graphitic carbon, the system comprising: one or more reactors adapted to contact at a temperature between 600 °C and 1 000 °C an iron oxide catalyst with the hydrocarbon feedstock to produce one or more mixed phase streams containing hydrogen gas and graphitic carbon,; and one or more solid/gas separators adapted to separate at least a portion of the one or more mixed phase streams of the one or more reactors into one or more gas streams comprising hydrogen gas and one or more solid streams comprising graphitic carbon..

[0008] In one form of the present invention, the or each reactor comprises a catalyst inlet, a feedstock inlet and a mixed phase outlet.

[0009] In one form of the present invention, the or each solid/gas separators comprise an inlet, a gas outlet and a solid outlet. Preferably, the inlet of at least one of the one or more solid/gas separators is in communication with at least one reactor mixed phase outlet.

[001 0] Where there are two or more reactors, the reactors may be arranged in series, parallel or a combination of each.

[001 1 ] It is understood by the inventors that the contact of the hydrocarbon feedstock with the iron oxide catalyst in the one or more reactors may not completely convert the hydrocarbon feedstock and iron oxide catalyst to hydrogen gas and graphitic carbon. Accordingly, the mixed phase stream may include unreacted hydrocarbon feedstock and unreacted iron oxide catalyst. It is envisaged that by directing either the mixed phase stream, the separated gas stream or the solid stream to downstream reactors may further complete the conversion to hydrogen gas and graphic carbon. [001 2] Where there are two or more reactors, at least a portion of a mixed phase stream, the gas stream and/or the solid stream may be fed into a downstream reactor to produce a further mixed phase stream.

[001 3] Where there are two or more reactors, iron oxide catalyst may be added to one or more of the downstream reactors.

[0014] Where there are two or more reactors, hydrocarbon feedstock may be added to one or more of the downstream reactors.

[001 5] Where there are two or more reactors in parallel, each reactor produces a mixed phase stream. The multiple mixed phase streams may be combined and at least a portion of the combined mixed phase stream may be fed into a single solid/gas separator, or at least a portion of each mixed phase stream may be fed into a dedicated solid/gas separator.

[001 6] Where there are two or more reactors arranged in series, at least a portion of a first mixed phase stream may be fed from a first reactor to a first solid/gas separator to produce a first gaseous stream and a first solid stream, wherein at least a portion of the first gaseous stream may be fed into a second reactor with additional iron oxide catalyst to produce a second mixed phase stream. Preferably, at least a portion of the second mixed phase stream may be fed from the second reactor to a second solid/gas separator to produce a second gaseous stream and a second solid stream.

[001 7] Where three or more reactors are arranged in series, at least a portion of the second gaseous stream may be fed into a third reactor with additional iron oxide catalyst to produce a third mixed phase stream. Preferably, at least a portion of a third mixed phase stream may be fed from the third reactor to a third solid/gas separator to produce a third gaseous stream and a third solid stream.

[001 8] Throughout this specification, unless the context requires otherwise, the term "residence time" will be understood to refer to the time in which the reactants are subjected to the selected temperature and pressure in a reactor. Residence time for example, does not include any time the reactants and/or products are in the reactors when the reactors are not operated at required temperature and pressure, nor does it include any time in which the reactants and/or products are outside of the reactor. One of skill in the art understands that more than three reactors may be arranged in a similar fashion such that the residence time of the gaseous feedstock and subsequent gaseous streams is increased over the one or more reactors. This embodiment is particularly advantageous in fluidised bed reactors where the residence time of the gas needs to be increased and/or the reactant particles in the fluidised bed are difficult to fluidise.

[001 9] Where two or more reactors are arranged in series, at least a portion of a first mixed phase stream may be fed from the first reactor to a first solid/gas separator to produce a first gaseous stream and a first solid stream, wherein the first solid stream may be fed into a second reactor with additional gaseous feedstock to produce a second mixed phase stream. Preferably, at least a portion of the second mixed phase stream may be fed from the second reactor to a second solid/gas separator to produce a second gaseous stream and a second solid stream.

[0020] Where three or more reactors are arranged in series, at least a portion of the second solid stream may be fed into a third reactor together with additional gaseous feedstock to produce a third mixed phase stream. Preferably, at least a portion of the third mixed phase stream may be fed from the third reactor to a third solid/gas separator to produce a third gaseous stream and a third solid stream.

[0021 ] One of skill in the art understands that more than three reactors may be arranged in a series such that the residence time of the catalyst and subsequent solid streams is increased over the one or more reactors. This embodiment is particularly advantageous in fluidised bed reactors where the residence time of the catalyst and subsequent solid streams needs to be increased and/or where the reactant particles in the fluidised bed fluidise readily. It is envisaged that the residence time may also be increased by decreasing the angle of repose of a rotating drum or continuous stirred tank reactor or by increasing the time reactants are maintained in the reactor.

[0022] Where two or more reactors are arranged in series, at least a portion of a first mixed phase stream may be fed from the first reactor to a first solid/gas separator to produce a first gaseous stream and a first solid stream, wherein the first gaseous stream and the first solid stream are fed into a second reactor to produce a second mixed phase stream. Preferably, at least a portion of the second mixed phase stream may be fed from the second reactor to a second solid/gas separator to produce a second gaseous stream and a second solid stream.

[0023] Where three or more reactors are arranged in series, at least a portion of the second gaseous stream and the second solid stream may be fed into a third reactor to produce a third mixed phase stream. Preferably, at least a portion of the third mixed phase stream may be fed from the third reactor to a third solid/gas separator to produce a third gaseous stream and a third solid stream.

[0024] Where two or more reactors are arranged in series, at least a portion of a first mixed phase stream may be fed from the first reactor to a next reactor without separation of the gas/solids.

[0025] Advantageously, the inventors have discovered that the use of a solid/gas separator between two reactors in series in order to separate at least a portion of the mixed stream into its separate components and then injecting them into a subsequent reactor avoids the difficulty in injecting a mixed phase stream into a reactor. This is particularly useful where the reactants must bypass a distributer plate, such as in a fluidised bed reactor. This embodiment is particularly advantageous in fluidised bed reactors where the residence time of the catalyst and subsequent solid streams, and gas streams needs to be increased.

[0026] One of skill in the art understands that more than three reactors may be arranged in series. This is particularly advantageous in fluidised bed reactors where the residence time of the catalyst and subsequent solid streams, and gas streams needs to be increased.

[0027] Where the system comprises two or more reactors, each of the two or more reactors operates at the same pressure and temperature as each other.

[0028] Where the system comprises two or more reactors, at least one of the two or more reactors operates at a different pressure to the other reactors.

[0029] Where the system comprises two or more reactors, at least one of the two or more reactors operates at a different temperature to the other reactors.

[0030] Where two or more reactors are used in series, at least a portion of the gaseous stream and the solid stream may be fed into downstream reactors in counter- current direction to one another. Preferably, each downstream reactor in the series operates at a lower pressure than the preceding reactor, allowing the gaseous stream to travel to reactors of lower pressure and the solid stream to travel to reactors of higher pressure. In the series arrangement, any unreacted hydrocarbon feedstock passes to a downstream reactor of lower pressure. Advantageously, the lower pressure will drive the reaction at a higher conversion rate towards thermodynamic completion, without being limited to the lower thermodynamic limit at higher pressures. In the series arrangement, any unreacted catalyst may be fed to an upstream reactor of higher pressure to contact additional hydrocarbon feedstock. Advantageously, the higher pressure increases the hydrocarbon penetration through the graphitic layers, which increases the utility of the catalyst and accesses higher graphitic purity.

[0031 ] Where two or more reactors are arranged in parallel, one or more of the reactors may be operated independently of each other reactor.

[0032] In accordance with a second aspect of the present invention, there is provided a system for the conversion of a hydrocarbon feedstock to hydrogen gas and graphitic carbon, the system comprising: two or more reactors adapted to contact at a temperature between 600 °C and 1 000 °C an iron oxide catalyst with the hydrocarbon feedstock to produce one or more mixed phase streams containing hydrogen gas and graphitic carbon, wherein the two or more reactors are arranged in parallel, such that one or more or the two or more reactors may be operated independently of each other reactor; and one or more solid/gas separators adapted to separate at least a portion of the one or more mixed phase streams of the two or more reactors into a gas stream comprising hydrogen gas and a solid stream comprising graphitic carbon,.

[0033] In one form of the present invention, each reactor comprises a catalyst inlet, a feedstock inlet and a mixed phase outlet.

[0034] In one form of the present invention, the or each solid/gas separators comprise an inlet, a gas outlet and a solid outlet. Preferably, the inlet of at least one of the one or more solid/gas separators is in communication with the reactor mixed phase outlets.

[0035] Advantageously, the independent operation of the reactors allows for the continuous processing of the hydrocarbon feedstock. More specifically, one reactor may be operated for a set period and then the operation of the reactor may be ceased, whilst the hydrocarbon feedstock may be diverted to one or more additional reactors. Once operation of a reactor has ceased, the contents may be allowed to settle for a period of time. In this manner, at least a portion of the solid particles suspended in the mixed phase may settle. The resulting mixed phase removed from the reactor then has a reduced solid content. Operation of the present invention in this manner may be particularly useful in applications where the production of hydrogen is favored over the graphite production or in applications where particular amounts or morphologies of graphite are required. The settled graphite material will then combine with any unreacted catalyst. Once the graphite and unreacted catalyst have settled in the reactor, the reactor can be de-pressurised and additional iron ore catalyst can be injected into the reactor. The reactor can then be repressurised and heated to recommence the thermocatalytic decomposition reaction. An advantage of this embodiment is that the system can be operated in a batch type process, which greatly simplifies the design and operation of the system by avoiding pressurised and heated addition of the iron ore catalyst. In addition, this embodiment is advantageous to purge the system of any solid particulate mixture that is not fluidising effectively.

[0036] In one form of the invention, the or each of the two or more reactors are configured to produce the same form or a different form of graphitic carbon.

[0037] In one form of the present invention, the iron oxide catalyst is low grade iron oxide catalyst. In an alternative form of the present invention, the iron oxide catalyst is a high grade iron oxide catalyst. Preferably, the iron oxide catalyst is a high grade iron oxide catalyst. More preferably, the high grade iron oxide catalyst is at least 95% pure, 96%, 97%, 98%, 99%, 99.5%, 99.99% or at least 99.995% pure.

[0038] Throughout this specification, unless the context requires otherwise, the term "low grade" will be understood to imply that the material is not synthesised. As would be understood by a person skilled in the art, synthesised materials are produced by the chemical reaction of precursor materials. Standard synthesis techniques for catalysts which are excluded from the present invention are, for example, impregnating nano- sized catalytic elements onto inert supports. Whilst the term "low grade" does include naturally occurring materials, it should not be understood to exclude materials that have gone through physical beneficiation such as crushing and screening or classification.

[0039] It is understood by the applicant that the process of contacting the iron oxide catalyst with the hydrocarbon feedstock more specifically comprises the steps of: reducing at least a portion of the iron oxide to iron; decomposing the hydrocarbon gas to produce hydrogen gas and an iron carbide intermediate; precipitating graphitic carbon on the surface of the iron; and fragmentation of the catalyst.

[0040] More specifically, the inventors understand that the gaseous feedstock adsorbs and disassociates on the surface of the iron oxide catalyst and the resulting carbon diffusing on the surface of the catalyst. Once the outer layer is saturated with carbon, it forms metal carbide and then precipitates from the metal grain boundaries as graphitic carbon. Over time this causes inter-granular pressure that separates the metal carbide particles from the catalyst, which causes the metal structure to disintegrate by "dusting". As such, the process is able to have high catalytic activity without requiring catalyst recovery, significantly increasing the economics of the process.

[0041 ] Without wishing to be bound by theory, the inventors understand that the above process enables the preferential physical separation of the dusted graphitic carbon coated iron particles from the parent iron oxide particles or gangue impurity. Advantageously, the graphitic carbon coated iron particles have a small particle size, allowing suspension of the graphitic carbon coated iron particles in the mixture of the gases in the reactor thereby forming the mixed phase stream.

[0042] Throughout the specification, unless otherwise stated, all pressures are provided in bar (gauge), with 0 bar being atmospheric pressure.

[0043] Preferably, at least one of the one or more reactors is operated at a pressure above atmospheric. Preferably, at least one of the one or more reactors is operated at a pressure between 0 and 1 00 bar/g.

[0044] In one form of the present invention, the mixed phase outlet may be in communication with the gas inlet. This communication allows for the mixed phase stream to be recycled through the one or more reactors for further catalytic conversion.

[0045] In one form of the present invention, the system comprises a pre-reactor conditioner. Preferably, the pre-reactor conditioner is adapted to condition the hydrocarbon feedstock prior to introduction to the one or more or each of the reactors. It is envisaged that the conditioning may comprise any one or more of heating, pressurising, plasma treatment, cooling, desulfurisation, drying, purification and expansion of the hydrocarbon feedstock.

[0046] In one form the present invention, the plasma treatment produces free radicals. Preferably, the free radicals include one of more of CH₄ ⁺ ; CH₃ ⁺ ; CH₂ ⁺ ; CH⁺ ; C⁺ ; C2 ⁺ ; C2H6 ⁺ ; C2H6 ⁺ ; C2H6 ; C2H5 ⁺ ; C2H₄ ⁺ ; C2H3 ⁺ ; C2H2 ⁺ ; C2H⁺ ; C3H8 ⁺ ; C3H8 ; C3H6 ⁺ ; C3H6 ; O2 ⁺ ; O2 ; 0⁺ ; O ; H2 ⁺ ; H⁺ ; H ; H₂0⁺ ; CO2 ⁺ ; CO⁺ ; and/or OH^" _.

[0047] In one form of the present invention, the hydrocarbon feedstock is heated to a temperature to within 50% below the reactor's operational temperature. . More preferably, the hydrocarbon feedstock is heated to a temperature to within 45% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 40% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 35% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 30% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 25% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 20% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 15% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 10% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 5% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 4% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 3% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 2% below the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 1 % below the reactor's operational temperature. It is understood by the inventors that elevating the hydrocarbon feedstock to a temperature near that of the operational temperature of the reactor provides reactor consistency in temperature, reduces the chance for side reactions, such as Fischer-Tropsch like reactions, to start, and lowers the thermal load required to heat the reactor(s).. [0048] In one form of the present invention, the hydrocarbon feedstock is heated to a temperature to within 1 % above the reactor's operational temperature. Preferably, the hydrocarbon feedstock is heated to a temperature to within 2% above the reactor's operational temperature. More preferably, the hydrocarbon feedstock is heated to a temperature to within 3% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 4% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 5% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 6% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 7% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 8% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 9% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 10% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 15% above the reactor's operational temperature. Still preferably, the hydrocarbon feedstock is heated to a temperature to within 20% above the reactor's operational temperature.

[0049] Without wishing to be bound by theory, the inventors understand that the plasma conditioning of the hydrocarbon feedstock prior to introduction into the one or more reactors will produce predominantly one radical form that will favour one morphology of graphite, preferably CNO, CNT, graphene, or CMS form.

[0050] In one form of the present invention, the system comprises a catalyst conditioner adapted to condition the catalyst. It is envisaged the catalyst conditioner may include one or more of beneficiation, washing, drying, crushing, milling, sieving, purification, heating, and chemical treatment of the catalyst.

[0051 ] As would be understood by a person skilled in the art, beneficiation is a process of increasing the percentage of iron in the catalyst. Methods of beneficiation may include density media separation, magnetic separation, hydroclassification.

Beneficiation not only increases the percentage of iron in the catalyst, it also leads to reduced impurity in the resultant graphitic product(s). It is understood by the applicant that beneficiation improves the efficiency of the process as there is less energy wasted on heating elements in the catalyst that do not take part in the catalytic reaction.

[0052] It is understood by the applicant that washing the catalyst will remove the smallest fractions of the catalyst material, resulting in a narrower particle size distribution. Advantageously, the narrow particle size distribution will assist in maintaining a fluidised state. In addition, washing the catalyst will wash off any water soluble impurities.

[0053] It is understood by the applicant that drying the catalyst will remove any excess moisture from the catalyst to thereby improve the efficiency of the process. Any water is vaporised from the catalyst before it is inserted into the reactor, which decreases the thermal energy required to bring the catalyst up to the temperature required for the reactor.

[0054] It is understood by the applicant that crushing/milling/sieving steps may be used to obtain preferred average particle size distribution of the catalyst (assist with fluidisation). Narrower particle size distribution assists in fluidising the catalytic particles.

[0055] It is understood by the applicant that purification/chemical treatment steps can be performed on the catalyst as a means to increase the purity of the catalyst.

[0056] It is understood by the applicant that heating the catalyst prior to insertion into the reactor reduces the heat load requirement of the reactor. The catalyst could, for example, be heated with waste heat streams from the reaction.

[0057] In one form of the present invention, the system further comprises a post- reactor conditioner adapted to remove heat from the mixed phase stream..

[0058] In one form of the present invention, the system further comprises a post- reactor conditioner adapted to condition the mixed phase stream. It is envisaged that the conditioning may comprise any one or more of pressurising, cooling, drying, and expansion of the mixed phase stream.

[0059] In one form of the present invention, the gas stream produced at the gas outlet of the one or more solid/gas separators comprise one or more of H₂, C0₂, CO, H₂O and CH₄, as well as impurities. H₂ and CH₄ form the majority of the gas stream with CO₂, H₂O and CO being present in trace amounts. [0060] In one form of the present invention, the gas outlet of the one or more solid/gas separators is in communication with a pre-gas separation conditioner adapted to condition the gas stream. It is envisaged that the conditioning may comprise any one or more of pressurising, cooling, drying, and expansion of the gas stream.

[0061 ] In one form of the present invention, at least a portion of the gas stream is recycled to other parts of the system. Preferably, at least a portion of the gas stream is used as a fuel source for heating the pre-reactor conditioner and/or as a fuel source for a reactor heater for heating the one or more reactors. The skilled person would be aware of appropriate heating means for use as the reactor heater, for example, the reactor heater may electrical and may be heated using electrical means or may comprise a burner and may be heated by burning a combustible gas to produce combustion gases. Suitable combustible gases include methane, hydrogen or a portion of the gas stream from the one or more reactors or solid/gas separators. Alternately or additionally, at least a portion of the gas stream may be fed into an electricity generator to be used as a fuel source for producing electricity, which optionally may be used to at least partially provide electricity to the system, such as, the reactor heater. Alternatively or additionally, at least a portion of the gas stream is fed into the pre-reactor conditioner for supply to the one or more reactors as the hydrocarbon feedstock.

[0062] In one form of the present invention, the reactor heater directly heats the one or more reactors. Preferably, the reactor heater directly heats the one or more reactors by injecting the combustion gases into the one or more reactors. In one form of the present invention, the combustion gases can be used as, or to supplement the hydrocarbon feedstock.

[0063] In an alternative form of the present invention, the reactor heater indirectly heats the one or more reactors. Preferably, the reactor heater indirectly heats the one or more reactors by injecting the combustion gases into one or more heating jackets that at least partially surrounds each of the one or more reactors.

[0064] In one form of the present invention, the gas outlet of pre-gas separation conditioner is in communication with a gas separator adapted to separate at least a portion of the gas stream into one or more purified gaseous product streams.

Preferably, the gas separator separates at least a portion of the gas stream into one or more purified gaseous product streams each exiting the gas separator at one or more purified gaseous product outlets. More preferably, the gas separator separates at least a portion of the gas stream into one or more purified gaseous product streams selected from the group comprising a purified H₂ stream, a purified CO stream, a purified C0₂ stream, and a purified CH₄ stream or the gas separator separates at least a portion of the gas stream into a purified H₂ stream and a mixed gaseous stream of one or more of CO, C0₂, and CH₄.

[0065] In one form of the present invention, at least a portion of the mixed gaseous stream is used as a fuel source for heating the pre-reactor conditioner and/or as a fuel source for the reactor heater for heating the one or more reactors.. Alternately or additionally, at least a portion of the mixed gaseous stream may be fed into a electricity generator to be used as a fuel source for producing electricity. Alternatively or additionally, at least a portion of the mixed gaseous stream may be fed into the pre- reactor conditioner for supply to the one or more reactors as the hydrocarbon feedstock.

[0066] In one form of the present invention, one or more of the one or more purified gaseous product outlets are in communication with a post-gas separation conditioner adapted to condition one or more of the purified H₂ stream, the purified CO stream, the purified C0₂ stream, and/or the purified CH₄ stream. It is envisaged that the

conditioning may comprise any one or more of pressurising or cooling of the purified gaseous product streams.

[0067] In one form of the present invention, the purified H₂ stream is passed to one or more gas storage tanks, piped to an end user, used as an energy source for one or each of the one or more of or all of the conditioners or the reactor heater, or optionally fed into the electricity generator for electricity generation. The electricity generation may be achieved using one or more of a fuel cell or direct combustion to drive a gas turbine or a gas engine.

[0068] In one form of the present invention, one or more of the purified gaseous product streams are recycled into other parts of the system. In one form of the present invention, the purified gaseous stream is mixed with the hydrocarbon feedstock in the pre-reactor conditioner for use in the one or more reactors. In one form of the present invention, the purified gaseous stream is used as a fuel source for heating the one or more of or all of the conditioners or is used as a fuel source for the reactor heater to heat the one or more reactors. In one form of the present invention, the mixed gaseous stream is mixed with the hydrocarbon feedstock in the pre-reactor conditioner for use in the one or more reactors. In one form of the present invention, the mixed stream is used as a fuel source for heating the one or more of or all of the conditioners or is used as a fuel source for the reactor heater to heat the one or more reactors.

[0069] In one form of the present invention, the solid stream comprises carbon in a variety of graphitic forms.

[0070] In one form of the present invention, the solid outlet of the one or more solid/gas separators are in communication with a solids conditioner adapted to condition the solid stream. Preferably, the solids conditioner conditions at least a portion of the solid stream into a conditioned solid product stream. Conditioning may include packaging (pellitising, compressing), functionalising, and/or purifying.

[0071 ] Where two pressurised reactors are used in series, the first reactor is at a pressure between 15 and 25 bar(g); and the second reactor is at a pressure between 0 and 1 bar(g).

[0072] In an alternate form of the present invention, three pressurised reactors are used in series. Where three pressurised reactors are used in series, the first reactor is at a pressure between 15 and 25 bar(g); the second reactor is at a pressure between 5 and 10 bar(g); and the third the first reactor is at a pressure between 0 and 1 bar(g).

[0073] In an alternate form of the present invention, four pressurised reactors are used in series. Where four pressurised reactors are used in series, the first reactor is at a pressure between 20 and 30 bar(g); the second reactor is at a pressure between 5 and 15 bar(g); the third reactor is at a pressure between 4 and 6 bar(g); and the fourth reactor is at a pressure between 0 and 1 bar(g).

[0074] In an alternate form of the present invention, five pressurised reactors are used in series. Where five pressurised reactors are used in series, the first reactor is at a pressure between 25 and 35 bar(g); the second reactor is at a pressure between 10 and 20 bar(g); the third reactor is at a pressure between 5 and 1 0 bar(g); the fourth reactor is at a pressure between 4 and 6 bar(g); and the fifth reactor is at a pressure between 0 and 1 bar(g).

[0075] Where two pressurised reactors are used in series, the first reactor is at a pressure between 0 and 1 bar(g); and the second reactor is at a pressure between 15 and 25 bar(g).

[0076] In an alternate form of the present invention, three pressurised reactors are used in series. Where three pressurised reactors are used in series, the first reactor is at a pressure between 0 and 1 bar(g); the second reactor is at a pressure between 5 and 10 bar(g); and the third the first reactor is at a pressure between 1 5 and 25 bar(g).

[0077] In an alternate form of the present invention, four pressurised reactors are used in series. Where four pressurised reactors are used in series, the first reactor is at a pressure between 0 and 1 bar(g); the second reactor is at a pressure between 4 and 6 bar(g); the third reactor is at a pressure between 5 and 1 5 bar(g); and the fourth reactor is at a pressure between 20 and 30 bar(g).

[0078] In an alternate form of the present invention, five pressurised reactors are used in series. Where five pressurised reactors are used in series, the first reactor is at a pressure between 0 and 1 bar(g); the second reactor is at a pressure between 4 and 6 bar(g); the third reactor is at a pressure between 5 and 1 0 bar(g); the fourth reactor is at a pressure between 10 and 20 bar(g); and the fifth reactor is at a pressure between 25 and 35 bar(g). [0079] In an alternate form of the present invention, five pressurised reactors are used in series. Where five pressurised reactors are used in series, the pressure in each reactor is between 0 and 10 bar(g).

[0080] In an alternate form of the present invention, four pressurised reactors are used in series. Where four pressurised reactors are used in series, the pressure in each reactor is between 0 and 10 bar(g).

[0081 ] In an alternate form of the present invention, three pressurised reactors are used in series. Where three pressurised reactors are used in series, the pressure in each reactor is between 0 and 10 bar(g).

[0082] In an alternate form of the present invention, two pressurised reactors are used in series. Where two pressurised reactors are used in series, the pressure in each reactor is between 0 and 10 bar(g).

[0083] Where two or more reactors are arranged in parallel, each reactor is adapted to selectively synthesise graphitic material with a desired morphology.

[0084] In an alternate form of the present invention, five pressurised reactors are used in parallel. Where five pressurised reactors are used in parallel, the pressure in each reactor is between 0 and 10 bar(g).

[0085] In an alternate form of the present invention, four pressurised reactors are used in parallel. Where four pressurised reactors are used in parallel, the pressure in each reactor is between 0 and 10 bar(g).

[0086] In an alternate form of the present invention, three pressurised reactors are used in parallel. Where three pressurised reactors are used in parallel, the pressure in each reactor is between 0 and 10 bar(g).

[0087] In an alternate form of the present invention, two pressurised reactors are used in parallel. Where two pressurised reactors are used in series, the pressure in each reactor is between 0 and 10 bar(g).

[0088] Where two or more reactors are arranged in parallel, each of the two or more reactors may be in series with one or more secondary reactors.

[0089] Where there are two or more reactors in series, each of the two or more reactors operate at the same pressure and temperature. [0090] Where there are two or more reactors in series, each of the two or more reactors operate at a different pressure and the same temperature.

[0091 ] Where there are two or more reactors in series, each of the two or more reactors operate at a different temperature and the same pressure.

[0092] Where there are two or more reactors in series, each of the two or more reactors operate at a different pressure and a different temperature.

[0093] It is envisaged by the applicant that the arrangement of one or more reactors in parallel would be advantageous in reducing the practical design complexity of the system.

[0094] Throughout this specification, unless the context requires otherwise, the term "selectively synthesise" will be understood refer to the preferential synthesis of one morphology over the others. Whilst the process of the present invention will often produce a mixture of morphologies, the Applicant has determined that the selection of the temperature and pressure of the process has an effect on the morphology of the graphite so produced.

[0095] As would be understood by a person skilled in the art, graphitic material can exist in many forms, such as: graphitic fibres, which are fibrous carbon structures typically ranging from 100 nm to 100 microns in length, carbon nano-tubes (CNTs), which are cylindrical nano- structures comprising single or multiple graphitic sheets aligned concentrically or perpendicular to a central axis also fall within the scope of graphitic fibres; carbon nano-onions (CNOs), which are structures that consist of multiple spherical graphitic sheets that are concentrically layered from a central core, which is typically a catalyst particle or a void. These carbon structures typically range from 50- 500nm in diameter; carbon micro-spheres (CMSs), which are hollow globular graphitic structures typically greater than 500nm in size. They are globular in shape and can be chain-like. The synthetic form of this graphite morphology is novel, having only been found naturally occurring in meteorites; and graphene, which is single-layer or single-digit layer sheets of graphite. [0096] Preferably, each of the one or more reactors may be adapted to selectively synthesise graphitic material with any one of carbon micro-spheres (CMSs), graphitic fibres, carbon nano-tubes (CNTs), carbon nano-onions (CNOs), or graphene

morphologies.

[0097] In one form of the present invention, CNOs are selectively synthesised where the reactor is adapted to contact at a temperature between 700 °C and 900 °C and a pressure between 0 bar(g) to 8 bar(g) the iron oxide catalyst with the hydrocarbon feedstock.

[0098] In one form of the present invention, the temperature is 800 °C to 900 °C and the pressure is 2 bar(g) to 4 bar(g). In an alternative form of the present invention, the temperature is 800 °C and the pressure is 2 bar(g). In an alternative form of the present invention, the temperature is 850 °C and the pressure is 2 bar(g). In an alternative form of the present invention, the temperature is 900 °C and the pressure is 2 bar(g). In an alternative form of the present invention, the temperature is 750 °C and the pressure is 8 bar(g). In an alternative form of the present invention, the temperature is 800 °C and the pressure is 8 bar(g).

[0099] In one form of the present invention, graphitic fibres are selectively synthesised where the reactor is adapted to contact at a temperature between 700 °C to 900 °C and a pressure between 0 bar(g) to 8 bar(g) the iron oxide catalyst with the hydrocarbon feedstock and the iron oxide catalyst is goethite iron oxide.

[001 00] Preferably, the temperature is 750 °C to 850 °C and the pressure is 0 bar(g) to 4 bar(g). More preferably, the temperature is 800 °C and the pressure is 0 bar(g).

[001 01 ] In one form of the present invention, the iron oxide catalyst is a purified or naturally occurring iron ore.

[001 02] In one form of the present invention, the iron oxide catalyst is an iron ore.

[001 03] In one form of the present invention, the iron ore is goethite ore.

[001 04] In one form of the present invention, the iron ore is low grade iron ore.

[001 05] In one form of the present invention, CMSs are selectively synthesised where the reactor is adapted to contact at a temperature between 800 °C to 900 °C and a pressure between 4 bar(g) to 9 bar(g) the iron oxide catalyst with the hydrocarbon feedstock.

[001 06] Preferably, the temperature is 850 °C to 900 °C and the pressure is 6 bar(g) to 8 bar(g). In an alternative form of the present invention, the temperature is 900 °C and the pressure is 8 bar(g). In a further alternative form of the present invention, the temperature is 850 °C and the pressure is 6 bar(g). More preferably, the temperature is 900 °C and the pressure is 6 bar(g). Ina further alternative form of the present invention, the temperature is 850 °C and the pressure is 7 bar(g). In a further alternative form of the present invention, the temperature is 900 °C and the pressure is 7 bar(g). In a further alternative form of the present invention, the temperature is 850 °C and the pressure is 8 bar(g). In a further alternative form of the present invention, the

temperature is 900 °C and the pressure is 4 bar(g). In a further alternative form of the present invention, the temperature is 900 °C and the pressure is 8 bar(g).

[001 07] In one form of the present invention, graphene is selectively synthesised where the reactor is adapted to contact at a temperature between 600 °C to 750 °C and pressure is 0 bar(g) to 1 bar(g) the iron oxide catalyst with the hydrocarbon feedstock.

[001 08] Preferably, the temperature is 600 °C to 700 °C and the pressure is 0 bar(g). More preferably, the temperature is 650 °C and the pressure is 0 bar(g).

[001 09] The one or more reactors may be selected from the group comprising static bed, continuous stirred tank reactor (CSTR), moving bed, agitated bed, fluidised bed, assisted fluidised bed, rotary bed, vibrating bed, plug flow or continuous flow stirred- tank reactors. Preferably, the one or more reactors are static bed, moving bed, CSTR or fluidised bed reactors. More preferably, when the one or more reactors are in series, the one or more reactors are fluidised bed reactors, rotary bed reactors, or CSTRs.

[001 10] In one form of the present invention, the catalyst is disposed on a

substantially horizontal surface of the reactor and subjected to a transverse flow of hydrocarbon feedstock. In a second form of the present invention, the catalyst is suspended in a fluidised bed reactor and the hydrocarbon feedstock is flowed through the fluidised bed.

[001 1 1 ] The hydrocarbon feedstock should preferably be at a higher pressure than the pressure of the one or more reactors to enable mass transport of the hydrocarbon feedstock into the one or more reactors. In one form of the present invention, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than about 100 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 90 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 80 bar(g).

Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 70 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 60 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 50 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 40 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 30 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 20 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 15 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 14 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 13 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 12 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 1 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 10 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 9 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 8 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 7 bar(g).

Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 6 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 5 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 4 bar(g).

Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 3 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 2 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is less than 1 bar(g).

[001 12] Preferably, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 1 00 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 90 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 80 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 70 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 60 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 50 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 40 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 30 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 20 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 1 5 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 10 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 9 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 8 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 7 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 6 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 5 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 4 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 3 to 1 bar(g). Alternatively, the pressure of the hydrocarbon feedstock entering the one or more reactors is between about 2 to 1 bar(g).

[001 13] In one form of the present invention, the temperature of the hydrocarbon feedstock entering the one or more reactors is between about 600-1000 °C,

Alternatively, the temperature of the hydrocarbon feedstock entering the one or more reactors is between about 650-1000 °C. Alternatively, the temperature of the hydrocarbon feedstock entering the one or more reactors is between about 700-1 000 °C. Alternatively, the temperature of the hydrocarbon feedstock entering the one or more reactors is between about 750-1000 °C. Alternatively, the temperature of the hydrocarbon feedstock entering the one or more reactors is between about 800-1 000°C. Alternatively, the temperature of the hydrocarbon feedstock entering the one or more reactors is between about 850-1000 °C. Alternatively, the temperature of the

hydrocarbon feedstock entering the one or more reactors is between about 900-1 000 or 950-1000 °C.

[001 14] The hydrocarbon feedstock is selected from any one of methane, LPG (liquid petroleum gas) biogas or natural gas/LNG (liquid natural gas). Alternatively, the hydrocarbon feedstock is selected from a gaseous hydrocarbon, such as methane, ethane, propane, pentane or any mixture thereof. It is envisaged that a biomass feedstock may be processed to produce a biogas feedstock to be used as the hydrocarbon feedstock.

[001 15] As discussed above, the iron oxide catalyst may be iron ore. In some embodiments, the iron oxide is used without any form of beneficiation. It is envisaged that iron ore may be removed directly from the quarry or mining site and used in the system of the present invention. Preferably, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 20 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 1 5 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 10 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 5 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 1 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 0.5 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors of less than 0.1 mm. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 900 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 800 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 700 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 600 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 500 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 400 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 300 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 200 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 100 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 90 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 80 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 70 μηι. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 60 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 50 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 40 μηι. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 30 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 20 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 10 μηι. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is less than 1 μιη.

[001 16] Preferably, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 1 0 μιη and 1000 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 20 μιη and 800 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 30 μιη and 600 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 40 μιη and 500 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 50 μιη and 400 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 60 μιη and 300 μιη.

Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 80 μιη and 250 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 80 μιη and 225 μιη.

Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 80 μιη and 220 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 85 μιη and 215 μιη.

Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 90 μιη and 210 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 95 μιη and 205 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is between 100 μιη and 200 μιη. Alternatively, the mean particle size of the iron oxide catalyst entering the one or more reactors is about 90 μη-ι, 95, 100, 105, 1 10, 1 1 5, 1 20, 130, 140, 145, 155, 160, 165, 1 70, 175, 1 80, 195, 200, 205 or 21 0 μιη.

[001 17] Throughout this specification, unless the context requires otherwise, the term "mean particle size" will be understood as the average particle size of the particulate material when obtained by wet or dry sieving or alternative means through a mesh of predetermined size. As would be understood by a person skilled in the art, the mean particle size can be determined by sieving the particulate material through various sized screens to obtain the desired particle size using wet or dry sieving techniques. Such screening methods are, for example, set out in several international standards for obtaining various characteristic particle sizes, ISO 9276 (representation of results of particle size analysis), which provide means for calculating and measuring mean particle sizes; ISO 565 and ISO 3310-1 provides details of mesh/screen sizing; and ISO 1441 .1 1 provides for sampling and testing aggregates for particle size distribution . Alternative methods for obtaining fractions of known mean particle size are known to those of skill in the art and include using cyclonic means (water, air, pneumatic), density separation/floatation.

[001 18] In one form of the present invention, at least 1 0 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 15 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 20 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 25 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 30 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 35 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 40 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 45 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 50 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 55 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 60 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 65 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 70 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 75 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 80 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, at least 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors.

[001 19] In one form of the present invention, between 40 % and 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors.

Alternatively, between 50 % and 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, between 55 % and 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors.

Alternatively, between 60 % and 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors. Alternatively, between 65 % and 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors.

Alternatively, between 70 % and 85 % of the hydrocarbon feedstock is catalytically converted in the one or more reactors.

[001 20] In one form of the present invention, the purity of the graphitic carbon in the solid stream is at least 50%. Alternatively, the pu rity of the graphitic carbon in the solid stream is at least 55%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 60%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 65%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 70%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 75%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 80%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 85%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 90%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 95%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 96%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 97%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 98%. Alternatively, the purity of the graphitic carbon in the solid stream is at least 99%.

[001 21 ] In one form of the present invention, the iron oxide catalyst is unsupported. In the context of the present invention and as understood by those skilled in the art, unsupported catalysts are catalysts which are not attached or bonded to a catalyst support, which is the material to which the catalyst is affixed. Catalyst supports are typically a solid material with a high surface area and are used to increase the available surface area of a catalyst to maximise the yield of a desired material. Extremely small catalyst particles with very high surface area tend to agglomerate when unsupported. Catalyst supports effectively allow such catalyst particles to be used without

agglomeration. Catalysts may also be supported in their natural state, that is, the surface of the iron oxide catalyst is coated/bonded with the active species and is supported by the core which may be different material to the iron oxide catalyst coating or the same material as the iron oxide catalyst coating.

[001 22] In an alternative form of the invention, the iron oxide catalyst is a supported catalyst. As would be understood by a person skilled in the art, the supported catalyst comprises the catalyst and a support. In one form of the present invention, the support is of a different chemical composition to the iron oxide catalyst. In an alternative form of the present invention, the support is of the same chemical composition as the iron oxide catalyst.

[001 23] In one form of the present invention the solid/gas separator is selected from the group comprising, a baghouse filter, a sintered metal filter and electrostatic precipitator.

[001 24] Preferably, the one or more reactors are selected from the group of static, moving or fluidized bed reactors.

[001 25] As would be understood by a person skilled in the art, the selections of the various gas conditioners used in the present invention will depended on the particular conditioning requirements. Where the gas stream requires heating, the gas conditioner is preferably selected from the group comprising a heat exchanger and a burner. Where the gas stream requires cooling, the gas conditioner is preferably a heat exchanger. Where the gas stream requires purification, the gas conditioner is preferably selected from the group comprising a water scrubber and a pressure swing adsorption concentrator. Where the gas stream requires pressurising, the gas conditioner is preferably a compressor. Where the gas stream requires despressuring, the gas conditioner is preferably an expander. [001 26] As would be understood by a person skilled in the art, the selections of the various solids conditioners used in the present invention will depended on the particular conditioning requirements. Where the solid stream requires heating, the solids conditioner is preferably selected from the group comprising a heat exchanger and a burner. Where the solid stream requires cooling, the solids conditioner is preferably a heat exchanger.

[001 27] The gas separator is preferably selected from separators that utilise pressure swing adsorption or membrane filtrations to separate one or more gas species.

BRIEF DESCRIPTION OF THE DRAWINGS

[001 28] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a schematic representation of the system in accordance with a first aspect of the present invention.

Figure 2 is a schematic representation of the system of Figure 1 in which two or more reactors are arranged in series.

Figure 3 is a schematic representation of the system of Figure 1 in which two or more reactors are arranged in series.

Figure 4 is a schematic representation of the system of Figure 1 in which two or more reactors are arranged in series.

Figure 5 is a schematic representation of Figure 1 in which two or more reactors are arranged in series.

Figure 6 is a schematic representation of the system in accordance with the second aspect of the present invention.

DESCRIPTION OF EMBODIMENTS

[001 29] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[001 30] The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, formulations and methods are clearly within the scope of the invention as described herein.

[001 31 ] The invention described herein may include one or more range of values (e.g. size, concentration etc). A range of values will be understood to include all values within the range, including the values defining the range, and values adjacent to the range which lead to the same or substantially the same outcome as the values immediately adjacent to that value which defines the boundary to the range.

[001 32] Other definitions for selected terms used herein may be found within the detailed description of the invention and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.

[001 33] Features of the invention will now be discussed with reference to the following non-limiting description and examples.

[001 34] In a general form, the invention relates to a system for producing hydrogen and graphitic carbon from a hydrocarbon feedstock. In particular, the present invention provides a process for catalytically converting a hydrocarbon feedstock to hydrogen and graphitic carbon using an iron oxide catalyst.

[001 35] Referring to Figure 1 , a system 10 for the conversion of a hydrocarbon feedstock 1 2 to hydrogen gas 14 and graphitic carbon 16 is shown. The hydrocarbon feedstock 1 2 is introduced into a pre-reactor conditioner 1 8 adapted to condition the hydrocarbon feedstock 12 to produce a conditioned hydrocarbon feedstock 20.

[001 36] The pre-reactor conditioner 18 is adapted to perform one or more of heating, pressurising, plasma treatment, cooling, desulfurisation, drying, purification and expansion of the hydrocarbon feedstock 12 producing a conditioned hydrocarbon feedstock 20.

[001 37] The pre-reactor conditioner is in communication with one or more reactors 26. The one or more reactors 26 are adapted to contact at a temperature between 600 °C and 1 000 °C a conditioned iron oxide catalyst 29 with the conditioned hydrocarbon feedstock 20 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon, and unreacted hydrocarbon. Each reactor 26 comprises a catalyst inlet 32, a gas inlet 34 and a mixed phase outlet 36. The pre-reactor conditioner will typically increase the temperature and pressure of the hydrocarbon feedstock prior to injection into the one or more reactors 26.

[001 38] In communication with the catalyst inlet 32 is a catalyst conditioner 37. The catalyst conditioner 37 is adapted to condition the iron oxide catalyst 28 prior to entry to the one or more reactors 26 to produce a conditioned iron oxide catalyst 29. It is envisaged the conditioning may include one or more of beneficiation, washing, drying, crushing, milling, sieving, purification, and heating of the catalyst.

[001 39] The mixed phase outlet 36 is in communication with a post-reactor conditioner 42. The post-reactor conditioner 42 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The post-reactor conditioner 42 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30, preferably post-reactor conditioner 42 cools and/or dewaters mixed phase stream 30.

[00140] The post-reactor conditioner 42 is in communication with one or more solid/gas separators 46. One or more solid/gas separator 46 comprise an inlet 52, a gas outlet 54, a second gas outlet 63, and a solid outlet 56. The one or more solid/gas separators 46 are adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon. It is envisaged that the second gas outlet 63 may optionally be in communication with one or more of the pre-reactor conditioner 18, reactor heater 65, and/or electricity generator 69 such that at least a portion of gas stream 48 may be recycled. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[00141 ] The solid outlet 56 is in communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 1 6. The solids conditioner 58 may perform one or more of the conditioning functions of packaging (pellitising, compressing), functionalising, and/or purifying the solid stream 50. [00142] The gas outlet 54 is in communication with a pre-gas separation conditioner 60, which comprises a conditioned gas outlet 61 , such that at least a portion of the gas stream 48 is conditioned to produce a conditioned gas stream 62. The pre-gas separation conditioner 60 may do any one or more of pressurising, cooling,

scrubbing/purification to remove impurities of the gas outlet product 48, preferably pre- gas separation conditioner 60 pressurises and/or scrubs gas stream 48.

[00143] The pre-gas separation conditioner 60 is in fluid connection with a gas separator 64 which is adapted to separate and purify at least a portion of the

components of the gas stream 62 to produce one or more purified gaseous product streams 66. At least one of the purified gaseous product streams 66 comprises hydrogen gas.

[00144] The gas separator 64 is in communication with a post-gas separation conditioner 68 adapted to condition the purified gaseous product streams 66 to provide hydrogen gas 14 in purified form and one or more conditioned gaseous streams 70 that may comprise one or more of CH₄, C0₂, CO or the mixed gaseous stream. Purified hydrogen stream 14 may be connected to one or more gas storage tanks, piped to an end user, or optionally used as an energy means for one or each of the one or more of or all of the conditioners 18, 42, 58, 60, 68 or reactor heater 65, or optionally fed into electricity generator 69 for electricity generation. Reactor heater 65 may directly or indirectly heat reactor 26. It is envisaged by the inventors that direct heating (not shown) will involve heating the reactor 26 by injection of combustion products from reactor heater 65 into reactor 26 in addition to the hydrocarbon feedstock 20. Indirect heating (shown) heats by indirect heat transfer of the heat from combustion into reactor 26 or by heating the hydrocarbon gas prior to or on injection into reactor 26. It is envisaged that indirect heating can include the use of heating jackets, heating coils, or heat exchangers and the like. The skilled person is aware of the different means of indirect heating that are known in the art and would be able to choose the appropriate means.

[00145] When conditioned gaseous product stream 70 comprises a mixed gaseous stream of one or more of CO, C0₂, and CH₄, the mixed gaseous stream may also be optionally connected to pre-reactor conditioner 18 for supply to the one or more reactors as the hydrocarbon feedstock or optionally fed into electricity generator 69 for electricity generation. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[00146] Referring to Figure 2, there is shown a system 1 00 for the conversion of a hydrocarbon feedstock 12 to hydrogen gas 14 and graphitic carbon 16. In so much as system 1 00 shares features with system 10, like numerals denote like parts. The hydrocarbon feedstock 12 is introduced into a pre-reactor conditioner 18 adapted to condition the hydrocarbon feedstock 18 to produce a conditioned hydrocarbon feedstock 20.

[00147] The pre-reactor conditioner 18 is adapted to perform one or more of heating, pressurising, plasma treatment, cooling, desulfurisation, drying, purification and expansion of the hydrocarbon feedstock 12 producing a conditioned hydrocarbon feedstock 20.

[00148] The pre-reactor conditioner is in communication with a first reactor 124. First reactor 1 24 is adapted to contact at a temperature between 600 °C and 1 000 °C a conditioned iron oxide catalyst 29 with the conditioned hydrocarbon feedstock 20 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon and unreacted hydrocarbon. The first reactor 124 comprises a catalyst inlet 32, a gas inlet 34, a mixed phase outlet 36. The mixed phase outlet 36 is in communication with a first post-reactor conditioner 142. The post-reactor conditioner 142 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The first post-reactor conditioner 142 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30, preferably the first post-reactor conditioner 142 cools and/or dewaters the mixed phase stream 30.

[00149] The first post-reactor conditioner 142 is in communication with a first solid/gas separator 146. The first solid/gas separator 146 comprises an inlet 52, a gas outlet 54 and a solid outlet 56. The first solid/gas separator 146 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon.

[001 50] The solid outlet 56 is in communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 1 6. The solids conditioner may perform one or more of the conditioning functions of packaging (pelletising, compressing), functionalising, and/or purifying the solid stream 50.

[001 51 ] The gas outlet 54 is in communication with a second pre-reactor conditioner 150 to condition gas stream 48. The second pre-reactor conditioner 150 is in

communication with the second reactor 126 to provide second conditioned hydrocarbon feedstock 1 52. Second conditioned hydrocarbon feedstock 1 52 comprises a mixture of hydrocarbons, hydrogen, and trace amounts of carbon monoxide and carbon dioxide. The second reactor 126 is adapted to contact at a temperature between 600 °C and 1000 °C a conditioned iron oxide catalyst 29 with the second conditioned hydrocarbon feedstock 1 52 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon, and unreacted hydrocarbon. The second reactor 126 comprises a catalyst inlet 32, a second conditioned hydrocarbon feedstock inlet 134 and a mixed phase outlet 36. The second pre-reactor conditioner 150 will typically increase the temperature and pressure of the second conditioned hydrocarbon feedstock to that of the second reactor 126.

[001 52] While the arrangement shown in Figure 2 demonstrates the use of two reactors 124, 126 in series, additional reactors may be included in the series to increase the proportion of hydrogen to methane in gas stream 48 by increasing gas residence time.

[001 53] In communication with the catalyst inlet 32 in the second reactor 1 26 is a catalyst conditioner 37. The catalyst conditioner 37 is adapted to condition the iron oxide catalyst 28 prior to entry to the second reactor 126 to produce a conditioned iron oxide catalyst 29. It is envisaged the conditioning may include one or more of beneficiation, washing, drying, crushing, milling, sieving, purification, and heating of the catalyst.

[001 54] The mixed phase outlet 36 is in communication with a second post-reactor conditioner 144. The second post-reactor conditioner 144 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The second post-reactor conditioner 144 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30.

[001 55] The post-reactor conditioner 144 is in communication with a second solid/gas separator 148. The solid/gas separator 148 comprise an inlet 52, a gas outlet 54, a second gas outlet 63, and a solid outlet 56. The second solid/gas separator 148 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon. It is envisaged that the second gas outlet 63 may optionally be in

communication with one or more of the pre-reactor conditioner 18, electricity generator 69, and/or reactor heater 65 such that at least a portion of gas stream 48 may be recycled. Reactor heater 65 may directly or indirectly heat first reactor 1 24 and/or second reactor 126. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[001 56] The solid outlets 56 of the first and second solid/gas conditioners are in communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 16. The solids conditioner may perform one or more of the conditioning functions of packaging

(pelletising, compressing), functionalising, and/or purifying the solid stream 50.

[001 57] The gas outlet 54 is in communication with a pre-gas separation conditioner 60, which comprise a conditioned gas outlet 61 , to produce a conditioned gas stream 62. The pre-gas separation conditioner 60 may do any one or more of pressurising, cooling, scrubbing/purification to remove impurities of the gas outlet product 48.

[001 58] The pre-gas separation conditioner 60 is in fluid connection with a gas separator 64 which is adapted to separate and purify at least a portion of the

[001 59] The gas separator 64 is in communication with a post-gas separation conditioner 68 adapted to condition the purified gaseous product streams 66 to provide hydrogen gas 14 in purified form and one or more conditioned gaseous streams 70 that may comprise one or more of CH₄, C0₂, CO or the mixed gaseous stream. Purified hydrogen stream 14 may be connected to one or more gas storage tanks, piped to an end user, or optionally used as an energy source for one or each of the one or more of or all of the conditioners 18, 142, 144, 1 50, 58, 60, 68 or reactor heater 65, or optionally fed into electricity generator 69 for electricity generation. [001 60] When conditioned gaseous product stream 70 comprises a mixed gaseous stream of one or more of CO, C0₂, and CH₄, the mixed gaseous stream may also optionally be connected to pre-reactor conditioner 18 for supply to the one or more reactors as the hydrocarbon feedstock, fed into electricity generator 69 for electricity generation, or optionally fed into reactor heater 65 for use as a combustible fuel.

Reactor heater 65 may directly or indirectly heat first reactor 124 and/or second reactor 126. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[001 61 ] Referring to Figure 3, there is shown a system 200 for the conversion of a hydrocarbon feedstock 12 to hydrogen gas 14 and graphitic carbon 16. In so much as system 200 shares feature with systems 10 and 100, like numerals denote like parts. The hydrocarbon feedstock 12 is introduced into a pre-reactor conditioner 18 adapted to condition the hydrocarbon feedstock 18 to produce a conditioned hydrocarbon feedstock 20.

[001 62] The pre-reactor conditioner 18 is adapted to perform one or more of heating, pressurising, plasma treatment, cooling, desulfurisation, drying, purification and expansion of the hydrocarbon feedstock 12 producing a conditioned hydrocarbon feedstock 20.

[001 63] The pre-reactor conditioner is in communication with a first reactor 124. First reactor 1 24 is adapted to contact at a temperature between 600 °C and 1 000 °C a conditioned iron oxide catalyst 29 with the conditioned hydrocarbon feedstock 20 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon and unreacted hydrocarbon. The first reactor 124 comprises a catalyst inlet 32, a gas inlet 34, a mixed phase outlet 36. The mixed phase outlet 36 is in communication with a first post-reactor conditioner 142. The first post-reactor conditioner 142 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The first post-reactor conditioner 142 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30.

[001 64] The first post-reactor conditioner 142 is in communication with a first solid/gas separator 146. The first solid/gas separator 146 comprises an inlet 52, a gas outlet 54 and a solid outlet 56. The first solid/gas separator 146 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon. [001 65] The solid outlet 56 is in communication with a second pre-reactor conditioner 150 to condition solid stream 50. The second pre-reactor conditioner 150 is in communication with the second reactor 126 to provide a second conditioned solid stream 250. The second reactor 126 is adapted to contact at a temperature between 600 °C and 1000 °C a conditioned solid stream 250 with the conditioned hydrocarbon feedstock 20 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon, and unreacted hydrocarbon. The second reactor 126 comprises a solid injection inlet 252, a gas inlet 34 and a mixed phase outlet 36. The pre-reactor conditioner will typically increase the temperature and pressure of the conditioned solid stream to that of the second reactor 126.

[001 66] While the arrangement shown in Figure 3 demonstrates the use of two reactors 124, 126 in series, additional reactors may be included in the series to increase the ratio of graphite to catalyst in solid stream 50 by increasing solid residence time.

[001 67] The mixed phase outlet 36 of the second reactor 126 is in communication with a second post-reactor conditioner 144. The second post-reactor conditioner 144 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The second post-reactor conditioner 144 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30.

[001 68] The post-reactor conditioner 144 is in communication with a second solid/gas separator 148. The solid/gas separator 148 comprise an inlet 52, a gas outlet 54, a second gas outlet 63, and a solid outlet 56. The second solid/gas separator 148 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon. It is envisaged that the second gas outlet 63 may be in communication with one or more of the pre-reactor conditioner 18 and/or reactor heater 65 such that at least a portion of gas stream 48 may be recycled. Reactor heater 65 may directly or indirectly heat first reactor 124 and/or second reactor 126.

[001 69] The solid outlet 56 of second solid/gas conditioner is in communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 16. The solids conditioner may perform one or more of the conditioning functions of packaging (pellitising, compressing),

functionalising, and/or purifying the solid stream 50. [001 70] The gas outlets 54 of the first and second solid/gas conditioners are in communication with a pre-gas separation conditioner 60, which comprises a conditioned gas outlet 61 , to produce a conditioned gas stream 62. The pre-gas separation conditioner 60 may do any one or more of pressurising, cooling, scrubbing/purification to remove impurities of the gas outlet product 48.

[001 71 ] The pre-gas separation conditioner 60 is in fluid connection with a gas separator 64 which is adapted to separate and purify at least a portion of the

[001 72] The gas separator 64 is in communication with a post-gas separation conditioner 68 adapted to condition the purified gaseous product streams 66 to provide hydrogen gas 14 in purified form and one or more conditioned gaseous streams 70 that may comprise one or more of CH₄, C0₂, CO or the mixed gaseous stream. Purified hydrogen stream 14 may be connected to one or more gas storage tanks, piped to an end user, used as an energy source for one or each of the one or more of or all of the conditioners 18, 142, 144, 1 50, 58, 60, 68 or reactor heater 65, or optionally fed into electricity generator 69 for electricity generation.

[001 73] When conditioned gaseous product stream 70 comprises a mixed gaseous stream of one or more of CO, CO₂, and CH₄, the mixed gaseous stream may also optionally be connected to pre-reactor conditioner 18 for supply to the one or more reactors as the hydrocarbon feedstock, used in reactor heater 65 as a fuel source, or optionally fed into electricity generator 69 for electricity generation. . Reactor heater 65 may directly or indirectly heat first reactor 124 and/or second reactor 126. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[001 74] Referring to Figure 4, there is shown a system 300 for the conversion of a hydrocarbon feedstock 12 to hydrogen gas 14 and graphitic carbon 16. In so much as system 300 shares feature with systems 10, 100, and 200, like numerals denote like parts. The hydrocarbon feedstock 12 is introduced into a pre-reactor conditioner 18 adapted to condition the hydrocarbon feedstock 18 to produce a conditioned

hydrocarbon feedstock 20. The pre-reactor conditioner 18 is adapted to perform one or more of heating, pressurising, plasma treatment, cooling, desulfurisation, drying, purification and expansion of the hydrocarbon feedstock 12 producing a conditioned hydrocarbon feedstock 20.

[001 75] The pre-reactor conditioner is in communication with a first reactor 124. First reactor 1 24 is adapted to contact at a temperature between 600 °C and 1 000 °C a conditioned iron oxide catalyst 29 with the conditioned hydrocarbon feedstock 20 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon and unreacted hydrocarbon. The first reactor 124 comprises a catalyst inlet 32, a gas inlet 34, a mixed phase outlet 36. The mixed phase outlet 36 is in communication with a first post-reactor conditioner 142. The first post-reactor conditioner 142 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The first post-reactor conditioner 142 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30.

[001 76] The first post-reactor conditioner 142 is in communication with a first solid/gas separator 146. The first solid/gas separator 146 comprises an inlet 52, a gas outlet 54 and a solid outlet 56. The first solid/gas separator 146 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon.

[001 77] The gas outlet 54 and the solid outlet 56 are in communication with a second pre-reactor conditioner 150 to condition solid stream 50 and gas stream 48. The second pre-reactor conditioner 150 is in communication with the second reactor 126 to provide a second conditioned solid stream 250 and a second conditioned hydrocarbon feedstock 1 52. The second conditioned hydrocarbon feedstock 152 comprises a mixture of hydrocarbons, hydrogen, and trace amounts of carbon monoxide and carbon dioxide.. The second reactor 126 is adapted to contact at a temperature between 600 °C and 1 000 °C a conditioned solid stream 250 with the second conditioned

hydrocarbon feedstock 152 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon, and unreacted hydrocarbon. The second reactor 1 26 comprises a solid injection inlet 252, a second conditioned hydrocarbon feedstock inlet 134 and a mixed phase outlet 36. The second pre-reactor conditioner will typically increase the temperature and pressure of the conditioned solid stream 250 and the second conditioned hydrocarbon feedstock 1 52 to that of the second reactor 126.

[001 78] While the arrangement shown in Figure 4 demonstrates the use of two reactors 124, 126 in series, additional reactors may be included in the series to increase the ratio of graphite to catalyst in solid stream 50 and the ratio of hydrogen to unreacted hydrocarbon feedstock in gas stream 48 by increasing solid and gas residence time.

[001 79] The mixed phase outlet 36 of the second reactor 126 is in communication with a second post-reactor conditioner 144. The second post-reactor conditioner 144 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The second post-reactor conditioner 144 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30.

[001 80] The post-reactor conditioner 144 is in communication with a second solid/gas separator 148. The solid/gas separator 148 comprise an inlet 52, a gas outlet 54, a second gas outlet 63, and a solid outlet 56. The second solid/gas separator 148 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon. It is envisaged that the second gas outlet 63 may be in communication with one or more of the pre-reactor conditioner 18, electricity generator 69, and/or reactor heater 65 such that at least a portion of gas stream 48 may be recycled.

[001 81 ] The solid outlet 56 of second solid/gas conditioner 148 is in communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 16. The solids conditioner may perform one or more of the conditioning functions of packaging (pellitising, compressing), functionalising, and/or purifying the solid stream 50.

[001 82] The gas outlet 54 of the second solid/gas conditioner is in communication with a pre-gas separation conditioner 60, which comprise a conditioned gas outlet 61 , to produce a conditioned gas stream 62. The pre-gas separation conditioner 60 may do any one or more of pressurising, cooling, scrubbing/purification to remove impurities of the gas outlet product 48.

[001 83] The pre-gas separation conditioner 60 is in fluid connection with a gas separator 64 which is adapted to separate and purify at least a portion of the

[001 84] The gas separator 64 is in communication with a post-gas separation conditioner 68 adapted to condition the purified gaseous product streams 66 to provide hydrogen gas 14 in purified form and one or more conditioned gaseous streams 70 that may comprise one or more of CH₄, C0₂, CO or the mixed gaseous stream. Purified hydrogen stream 14 may be connected to one or more gas storage tanks, piped to an end user, or optionally used as an energy source for one or each of the one or more of or all of the conditioners 18, 142, 144, 1 50, 58, 60, 68 or reactor heater 65, or optionally fed into electricity generator 69 for electricity generation.

[001 85] When conditioned gaseous product stream 70 comprises a mixed gaseous stream of one or more of CO, C0₂, and CH₄, the mixed gaseous stream may also be connected to pre-reactor conditioner 18 for supply to the one or more reactors as the hydrocarbon feedstock or optionally fed into electricity generator 69 for electricity generation. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[001 86] Referring to Figure 5, there is shown a system 400 for the conversion of a hydrocarbon feedstock 12 to hydrogen gas 14 and graphitic carbon 16. In so much as system 400 shares feature with system 10, 100, 200, and 300, like numerals denote like parts. The hydrocarbon feedstock 12 is introduced into a pre-reactor conditioner 18 adapted to condition the hydrocarbon feedstock 18 to produce a conditioned

[001 87] The pre-reactor conditioner is in communication with a first reactor 124. First reactor 1 24 is adapted to contact at a temperature between 600 °C and 1000 °C a second conditioned solid stream 415 with the conditioned hydrocarbon feedstock 20 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon and unreacted hydrocarbon. The first reactor 124 comprises a solids inlet 410, a gas inlet 34, a mixed phase outlet 36. The mixed phase outlet 36 is in communication with a first post-reactor conditioner 142. The first post-reactor conditioner 142 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The first post-reactor conditioner 142 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30.

[001 88] The first post-reactor conditioner 142 is in communication with a first solid/gas separator 146. The first solid/gas separator 146 comprises an inlet 52, a gas circulation outlet 416 and a solid outlet 56. The first solid/gas separator 146 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a circulating gas stream 420 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon.

[001 89] The solid outlet 56 of the first second solid/gas conditioner is in

communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 16. The solids conditioner may perform one or more of the conditioning functions of packaging

(pellitising, compressing), functionalising, and/or purifying the solid stream 50.

[001 90] The circulating gas outlet 416 is in communication with a second pre-reactor conditioner 150 to condition circulation gas stream 420. The second pre-reactor conditioner 150 is in communication with the second reactor 126 to provide a second conditioned hydrocarbon feedstock 1 52. Second conditioned hydrocarbon feedstock 152 comprises a mixture of hydrocarbons, hydrogen, and trace amounts of carbon monoxide and carbon dioxide. The second reactor 126 is adapted to contact at a temperature between 600 °C and 1 000 °C a conditioned iron oxide catalyst 29 with the second conditioned hydrocarbon feedstock 152 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon, and unreacted hydrocarbon. The second reactor 1 26 comprises a catalyst inlet 32, a second conditioned hydrocarbon feedstock inlet 134 and a mixed phase outlet 36. The second pre-reactor conditioner 1 50 will typically increase the temperature and pressure of the second conditioned hydrocarbon feedstock 1 52 to that of the second reactor 126.

[001 91 ] While the arrangement shown in Figure 5 demonstrates the use of two reactors 124, 126 in series, additional reactors may be included in the series to increase to ratio of graphite to catalyst in solid stream 50 and the ratio of hydrogen to unreacted hydrocarbon feedstock in gas stream 48 by increasing solid and gas residence time, without being limited by the lower thermodynamic limit at elevated pressures.

[001 92] The mixed phase outlet 36 of the second reactor 126 is in communication with a second post-reactor conditioner 144. The second post-reactor conditioner 144 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The second post-reactor conditioner 144 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30. [001 93] The second post-reactor conditioner 144 is in communication with a second solid/gas separator 148. The solid/gas separator 148 comprise an inlet 52, a gas outlet 54, a second gas outlet 63, and a circulating solid outlet 41 2. The second solid/gas separator 148 is adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a circulating solid stream 414 comprising uncreacted catalyst and graphitic carbon. It is envisaged that the second gas outlet 63 may be in communication with one or more of the pre-reactor conditioner 18, electricity generator 69, and/or reactor heater 65 such that at least a portion of gas stream 48 may be recycled. Reactor heater 65 may directly or indirectly heat first reactor 124 and/or second reactor 126.

[001 94] The second solid/gas separation unit is in communication with a third pre- reactor conditioner 422, which is adapted to condition circulating solid stream 414 to provide a second conditioned solid stream 415. Third pre-reactor conditioner 422 is in communication with first reactor 124 to provide delivery of the second conditioned solid stream 415 to the solids inlet 410 in the first reactor 124.

[001 95] The gas outlet 54 of the second solid/gas conditioner is in communication with a pre-gas separation conditioner 60, which comprise a conditioned gas outlet 61 , to produce a conditioned gas stream 62. The pre-gas separation conditioner 60 may do any one or more of pressurising, cooling, scrubbing/purification to remove impurities of the gas outlet product 48.

[001 96] The pre-gas separation conditioner 60 is in fluid connection with a gas separator 64 which is adapted to separate and purify at least a portion of the

[001 97] The gas separator 64 is in communication with a post-gas separation conditioner 68 adapted to condition the purified gaseous product streams 66 to provide hydrogen gas 14 in purified form and one or more conditioned gaseous streams 70 that may comprise one or more of CH₄, C0₂, CO or the mixed gaseous stream. Purified hydrogen stream 14 may be connected to one or more gas storage tanks, piped to an end user, or optionally used as an energy source for one or each of the one or more of or all of the conditioners 18, 142, 144, 1 50, 422 58, 60, 68 or reactor heater 65, or optionally fed into electricity generator 69 for electricity generation. [001 98] When conditioned gaseous product stream 70 comprises a mixed gaseous stream of one or more of CO, C0₂, and CH₄, the mixed gaseous stream may also optionally be connected to pre-reactor conditioner 18 for supply to the one or more reactors as the hydrocarbon feedstock or optionally fed into electricity generator 69 for electricity generation. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[001 99] Referring to Figure 6, there is shown a system 500 for the conversion of a hydrocarbon feedstock 12 to hydrogen gas 14 and graphitic carbon 16 in accordance with a second aspect of the present invention. In so much as system 500 shares features with system 10, 100, 200, 300, and 400, like numerals denote like parts. The hydrocarbon feedstock 12 is introduced into a pre-reactor conditioner 18 adapted to condition the hydrocarbon feedstock 18 to produce a conditioned hydrocarbon feedstock 20.

[00200] The pre-reactor conditioner is in communication with two or more reactors 650. Each reactor is adapted to contact at a temperature between 600 °C and 1 000 °C an iron oxide catalyst 28 with the heated hydrocarbon feedstock 24 to produce a mixed phase stream 30 containing hydrogen gas, graphitic carbon and unreacted

hydrocarbon. Each of the two or more reactor 650 comprises a catalyst inlet 32, a gas inlet 34, a mixed phase outlet 36, and an optional solid outlet 660. The pre-reactor conditioner will typically increase the temperature and pressure of the second conditioned hydrocarbon feedstock to that of the two or more reactors 650. Each of the solids outlets 660 in the two or more reactors is in communication with solids conditioners 58 via solid inlets 658.

[00201 ] The two or more reactors 650 are arranged in parallel. In the parallel arrangement, both the hydrocarbon feedstock 24 and iron oxide catalyst 28 streams may be directed to each of the two or more reactors 650 independently. This arrangement allows for independent operation of each of the two or more reactors 650. The independent operation of the two or more reactors 650 has been found to be particularly advantageous as operation of individual reactors may be ceased while maintaining the processing of the hydrocarbon feedstock 12 in other reactors. By ceasing operation of a reactor for a period of time following the operation of the reactor, at least of portion of the solid graphite reactor will settle and may be moved via sold outlet 662 to solids conditioners 58. [00202] The mixed phase outlet 36 is in communication with a post-reactor conditioner 42. The post-reactor conditioner 42 is adapted to condition the mixed phase stream 30 to produce a conditioned mixed phase stream 44. The post-reactor conditioner 42 may do any one or more of dewatering, cooling, and/or extraction of volatiles of the mixed phase stream 30, preferably post-reactor conditioner 42 cools and/or dewaters mixed phase stream 30.

[00203] The post-reactor conditioner 42 is in communication with one or more solid/gas separators 46. One or more solid/gas separator 46 comprise an inlet 52, a gas outlet 54, a second gas outlet 63, and a solid outlet 56. The one or more solid/gas separators 46 are adapted to separate at least a portion of the conditioned mixed phase stream 44 into a gas stream 48 comprising hydrogen gas and a solid stream 50 comprising graphitic carbon. It is envisaged that the second gas outlet 63 may be in communication with one or more of the pre-reactor conditioner 18 and/or reactor heater 65 such that at least a portion of gas stream 48 may be recycled. Reactor heater 65 may directly or indirectly two or more reactors 650.

[00204] The solid outlet 56 is in communication with a solids conditioner 58. The solids conditioner 58 is adapted to condition the solid stream 50 to produce a graphitic carbon stream 1 6. The solids conditioner may perform one or more of the conditioning functions of packaging (pellitising, compressing), functionalising, and/or purifying the solid stream 50.

[00205] The gas outlet 54 is in communication with a pre-gas separation conditioner 60, which comprise a conditioned gas outlet 61 , such that at least a portion of the gas stream 48 is conditioned to produce a conditioned gas stream 62. The pre-gas separation conditioner 60 may do any one or more of pressurising, cooling,

scrubbing/purification to remove impurities of the gas outlet product 48.

[00206] The pre-gas separation conditioner 60 is in fluid connection with a gas separator 64 which is adapted to separate and purify at least a portion of the

[00207] The gas separator 64 is in communication with a post-gas separation conditioner 68 adapted to condition the purified gaseous product streams 66 to provide hydrogen gas 14 in purified form and one or more conditioned gaseous streams 70 that may comprise one or more of CH₄, C0₂, CO or the mixed gaseous stream. Purified hydrogen stream 14 may be connected to one or more gas storage tanks, piped to an end user, or optionally used as an energy source for one or each of the one or more of or all of the conditioners 18, 42, 58, 60, 68 or reactor heater 65, or optionally fed into electricity generator 69 for electricity generation.

[00208] When conditioned gaseous product stream 70 comprises a mixed gaseous stream of one or more of CO, C0₂, and CH₄, the mixed gaseous stream may also optionally be connected to pre-reactor conditioner 18 for supply to the one or more reactors as the hydrocarbon feedstock or optionally fed into electricity generator 69 for electricity generation. Electricity generator 69 may optionally be used to provide electricity 80 to reactor heater 65 or to other parts of the system, as required.

[00209] The arrangement shown in Figure 6 demonstrates the use of two reactors 250 in parallel. Such an arrangement simplifies the practical design of a commercial plant implementing the system described herein.

[00210] While the arrangement shown in Figure 6 demonstrates the use of two or more reactors 250 in parallel, the skilled person understands that each of the two or more reactors may be comprised of two or more secondary reactors used in series in any one of the arrangements described herein.

[0021 1 ] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. The invention includes all such variation and modifications. The invention also includes all of the steps, features, formulations and compounds referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

Claims

1 . A system for the conversion of a hydrocarbon feedstock to hydrogen gas and graphitic carbon, the system comprising: one or more reactors adapted to contact at a temperature between 600 °C and 1 000 °C an iron oxide catalyst with the hydrocarbon feedstock to produce one or more mixed phase streams containing hydrogen gas and graphitic carbon; and one or more solid/gas separators adapted to separate at least a portion of the one or more mixed phase streams of the one or more reactors into one or more gas streams comprising hydrogen gas and one or more solid streams comprising graphitic carbon.

2. A system according to claim 1 , wherein there are two or more reactors and the

reactors are arranged in series, parallel or a combination of both.

3. A system according to claim 2, wherein each reactor is in communication with at least one solid/gas separator.

4. A system according to claims 2 or 3, wherein at least a portion of one or more of the mixed phase stream, the gas stream and the solid stream is fed into a downstream reactor.

5. A system according to any one of claims 2 to 4, wherein additional iron oxide

catalyst is added to one or more of the downstream reactors.

6. A system according to any one of claims 2 to 5, wherein additional hydrocarbon

feedstock is added to one or more of the downstream reactors.

7. A system according to any one of the preceding claims, wherein each downstream reactor in the series operates at a lower pressure than the preceding reactor,

8. A system according to claim 8, wherein the and the gaseous stream is fed to

downstream reactors and the solid stream is fed to upstream reactors.

9. A system for the conversion of a hydrocarbon feedstock to hydrogen gas and

graphitic carbon, the system comprising: two or more reactors adapted to contact at a temperature between 600 °C and 1000 °C an iron oxide catalyst with the hydrocarbon feedstock to produce a one or more mixed phase streams containing hydrogen gas and graphitic carbon, wherein the two or more reactors are arranged in parallel, such that one or more or the two or more reactors may be operated independently of each other reactor; and one or more solid/gas separators adapted to separate at least a portion of the one or more mixed phase streams of the two or more reactors into a gas stream comprising hydrogen gas and a solid stream comprising graphitic carbon.

10. A system according to any one of claims 1 to 7 or 9, wherein the system comprises two or more reactors and each of the two or more reactors are operated at the same pressure and temperature as each other.

1 1 . A system according to any one of claims 1 to 9, wherein the system comprises two or more reactors and at least one of the two or more reactors is operated at a temperature and/or pressure independent of the other reactors.

12. A system according to any one of claims 1 to 1 1 , wherein two or more reactors are arranged in parallel and one or more of the reactors may be operated independently of each other reactor.

13. A system according to any one of the preceding claims, wherein the or each reactor comprises a catalyst inlet, a feedstock inlet and a mixed phase outlet.

14. A system according to any one of the preceding claims, wherein the or each

solid/gas separators comprise an inlet, a gas outlet and a solid outlet.

15. A system according to claim 14 wherein the inlet of at least one of the one or more solid/gas separators is in communication with at least one reactor mixed phase outlet.

16. A system according to any one of the preceding claims, wherein the iron oxide

catalyst is a low grade iron oxide catalyst.

17. A system according to claim 1 6, wherein the low grade iron oxide catalyst is iron ore

18. A system according to any one of claims 1 to 15, wherein the iron oxide catalyst is a high grade iron oxide catalyst.

19. A system according to any one of claims 1 to 18, wherein the or each of the reactors is operable at a pressure above atmospheric, preferably at a pressure between 0 and 1 00 bar(g), and particularly preferably at a pressure between 0 and 1 0 bar(g).

20. A system according to any one of claims 1 to 19, wherein the or each reactor may be adapted to selectively synthesise graphitic material with any one of carbon microspheres (CMSs), graphitic fibres, carbon nano-tubes (CNTs), carbon nano-onions (CNOs), or graphene morphologies.

21 . A system according to any one of claims 1 to 20, wherein the or each reactor is selected form the group comprising static bed, continuous stirred tank reactor (CSTR), moving bed, agitated bed, fluidised bed, assisted fluidised bed, rotary bed, vibrating bed, plug flow or continuous flow stirred-tank reactors or any mixture of reactors thereof.

22. A system according to any one of claims 1 to 21 , wherein the iron oxide catalyst is a self supported catalyst.

23. A system according to any one of claims 9 to 22, wherein each reactor in parallel may be in series with one or more reactors.