Methods and reactors for direct catalytic conversion of hydrocarbons to hydrogen

Abstract

An integrated system for converting hydrocarbons gases to solid carbon and hydrogen products includes a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, a heating section in fluid communication with the pyrolysis reactor, a separator system in fluid communication with the pyrolysis reactor through the product gas outlet, and a heat exchanger configured to remove heat from the reaction product gases exiting the pyrolysis reactor. The bed of particulates comprises catalyst particles, solid carbon, and inert media. The heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet, and the separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor.

Description

METHODS AND REACTORS FOR DIRECT CATALYTIC CONVERSION OF HYDROCARBONS TO HYDROGENCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 514,787 filed on July 20, 2023 and entitled, “METHODS FOR DIRECT CATALYTIC CONVERSION OF HYDROCARBONS TO HYDROGEN,’; the entire disclosure of which is incorporated herein by reference.STATEMENT REGARDING GOVERNMENTALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] None.BACKGROUND

[0003] The pyrolysis of low-cost hydrocarbon feedstocks including petroleum and natural gas produces solid carbon and gas phase molecular hydrogen. For example, the conversion can occur according to the following equation:

[0004] This reaction has the potential for producing a hydrogen product without carbon dioxide which is a major challenge in society today. In the absence of a catalyst, the reaction requires very high temperatures (T >1000 °C) and there are many technical challenges associated with heat management in such high temperature processes. Further, the carbon product produced is typically associated with polycyclic hydrocarbon contaminants. To date there have been no significant commercial processes using pyrolysis to produce hydrogen as a primary product.SUMMARY

[0005] In some embodiments, a chemical reactor for converting hydrocarbons gases to solid carbon and hydrogen products comprises a reactor vessel and a bed of particulates disposed within the reactor vessel. The reactor vessel comprises a first inlet for hydrocarbon gases, a second inlet for catalyst or catalyst precursors, a third inlet for inert media, one or more first outlets for product gases, and product solids with catalyst, or both, and one or more second outlets for inert media. A diameter of the reactor vessel varies along a height of the reactor vessel, and the diameter of the reactor vessel defines at least three distinct zones each having differentdiameters. The at least three distinct zones are configured to have different gas-solid interactions based on the different diameters, and the diameter is configured to control a gas velocity within the reactor vessel to control gas-solid interactions within the reactor to allow varying degrees of fluidization of the solids within the reactor vessel. The bed of particulates comprises catalyst particles, solid carbon, and inert media in a stratified arrangement, and the bed of particulates is configured to become partially or wholly segregated under the influence of gases flowing upwards through the reactor vessel.

[0006] In some embodiments, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises: passing a feed gas comprising hydrocarbon gases into a reactor vessel, passing the feed gas through a bed of particulates disposed within the reactor vessel, forming solid carbon and hydrogen as the feed gas passes through the bed of particulates, and stratifying the bed of particulates in response to passing the feed gas through the bed of particulates. The reactor vessel comprises a first inlet for hydrocarbon gases, a second inlet for catalyst or catalyst precursors, a third inlet for inert media, and a first outlet for product gases and product solids with catalyst, and a second outlet for inert media. A diameter of the reactor vessel varies along a height of the reactor vessel, and the diameter of the reactor vessel defines at least three distinct zones each having different diameters. The bed of particulates comprises catalyst particles, solid carbon, and inert media in a stratified arrangement, and the bed of particulates partially or wholly segregates under the influence of the feed gas flow ing upwards through the reactor vessel.

[0007] In some embodiments, an integrated system for converting hydrocarbons gases to solid carbon and hydrogen products comprises: a preheater configured to exchange heat between a feed stream of hydrocarbon gases and reaction product gases, a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, a heating section in fluid communication with the pyrolysis reactor, a separator system in fluid communication with the pyrolysis reactor through the product gas outlet, a heat exchanger configured to remove heat from the reaction product gases exiting the pyrolysis reactor. The bed of particulates comprises catalyst particles, solid carbon, and inert media, and the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for heated inert media particles near a top of the bed of particulates, an outlet for the inert media near a bottom of the bed of particulates. The heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet. The separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor.

[0008] In some embodiments, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises heating a feed stream to produce a heated feed stream by exchanging heat between the feed stream and a reaction product gas stream, passing the heated feed stream to a pyrolysis reactor, contacting the heated feed stream with the catalyst particles to form reaction products comprising solid carbon and hydrogen from the hydrocarbon gas, removing a portion of the inert media from the bed of particulates during the contacting, heating the inert media removed from the bed of particulates in a heating section to form heated inert media, passing the heated inert media back to the bed of particulates, separating the reaction products to form a solid carbon product and a gaseous product, and extracting heat from the reaction products downstream of the pyrolysis reactor. The feed stream comprises hydrocarbon gas, and the pyrolysis reactor comprises a bed of particulates disposed in a reactor vessel. The bed of particulates comprises catalyst particles, solid carbon, and inert media.

[0009] In some embodiments, an integrated system for converting hydrocarbons gases to solid carbon and hydrogen products comprises a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, a heating section in fluid communication with the pyrolysis reactor, and a carbon formation reactor in fluid communication with an outlet of the heating section. The bed of particulates comprises catalyst particles, solid carbon, and inert media, and the pyrolysis reactor comprises a feed gas inlet at a low er portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for heated inert media particles near a top of the bed of particulates, an outlet for the inert media near a bottom of the bed of particulates. The heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet. The carbon formation reactor is configured to receive the hot gas stream from the heating section and convert at least a portion of carbon oxides in the hot gas stream to solid carbon and water.

[0010] In some embodiments, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises passing a feed stream through a bed of particulates in a reactor vessel, forming a product stream within the reactor vessel based on reacting the feed stream with the catalyst particles, passing a portion of the inert media from the reactor vessel to a heating section, combusting a combustion gas in the heating section to produce combustion products, contacting the combustion products with the inert media to produce heated inert media, passing the combustion products to a carbon formation reactor, and converting at least a portion of the carbon oxides in the combustion products to solid carbon within the carbon formation reactor. The feed stream comprises hydrocarbon gas, and the bed of particulates comprises catalystparticles, solid carbon, and inert media. The product stream comprises solid carbon and hydrogen, and the combustion products comprise carbon oxides.

[0011] In some embodiments, an integrated system for converting hydrocarbons gases to solid carbon and hydrogen products comprises a preheater configured to exchange heat between a feed stream of hydrocarbon gases and a heated particulate stream to produce a cold solids stream, a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, a separator system in fluid communication with the pyrolysis reactor through the product gas outlet, and a heat exchanger configured to exchange heat between the cold solids stream and the product gas. The bed of particulates comprises catalyst particles, solid carbon, and inert media, and the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for inert media particles near a top of the bed of particulates, an outlet for the inert media near a middle of the bed of particulates. The pyrolysis reactor is configured to convert a hydrocarbon gas into solid carbon and hydrogen in the bed or particulates, and the separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor.

[0012] In some embodiments, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises: heating a feed stream using heat exchange with a particulate stream to produce a heated feed stream and a cold solids stream, passing the heated feed stream to a pyrolysis reactor, converting the hydrocarbon gas to a product stream comprising solid carbon and hydrogen within the pyrolysis reactor, exchanging heat between the cold solids stream and the product stream to form a heated solids stream, and passing the heated solids stream back to the pyrolysis reactor. The feed stream comprises hydrocarbon gas, and the pyrolysis reactor comprises a bed of particulates disposed in a reactor vessel. The bed of particulates comprises catalyst particles, solid carbon, and inert media.

[0013] These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For a more complete understanding of the present disclosure, reference is now made to the following brief descri ption. taken in connection with the accompanying drawings and detailed description:

[0015] Figure 1 shows schematically how iron containing catalysts evolve according to some embodiments.

[0016] Figure 2 is a schematic diagram of the pyrolysis process according to some embodiments.

[0017] Figures 3 is a schematic diagram of a pyrolysis reactor whereby heat is provided by way of a circulating inert media according to some embodiments.

[0018] Figure 4 is a schematic of a variable diameter two-phase reactor whereby different gas solid behavior is achieved in each reactor zone according to some embodiments according to some embodiments.

[0019] Figure 5 is another schematic of a variable diameter two-phase reactor with 4 zones according to some embodiments.

[0020] Figure 6 is a process flow diagram of a preferred integrated process according to some embodiments.

[0021] Figure 7 is a schematic diagram of a combustor according to some embodiments.

[0022] Figure 8 is a process diagram of the pyrolysis process with combustion gases converted to carbon according to some embodiments.

[0023] Figure 9 is a block flow diagram of an integrated process with carbon dioxide conversion to solid carbon according to some embodiments.

[0024] Figure 10 shows block flow diagrams of a configuration with carbon dioxide conversion to solid carbon block flow.

[0025] Figure 11 shows schematic diagram of a pyrolysis reactor with separation according to some embodiments.

[0026] Figure 12 shows performance data from an integrated process.

[0027] Figure 13 shows a chart showing stratification criteria.

[0028] Figure 14 shows a fluidization map.

[0029] Figure 15 shows an approach temperature and flow ratio diagram.

[0030] Figure 16 shows a schematic representation of a heat integrated pyrolysis reactor system according to some embodiments.DESCRIPTION

[0031] The processes, systems, and methods disclosed herein demonstrate how molecular hydrogen production from the decomposition of hydrocarbon feedstocks without net generation of carbon oxides can be facilitated in an integrated chemical process consisting of a unique tw o- phase reactor containing different solids including a condensed phase catalyst and gas-phase chemicals heated by continuous circulation of externally heated inert solid materials, which can be referred to as an inert media herein, and specific means for heat integration. Specific processconfigurations are disclosed with heat integration to maximize the hydrogen yield per kg of hydrocarbon feedstock and minimize the added energy required. Furthen in some embodiments, hydrocarbon fuels can be used for heat generation by way of combustion and the carbon oxides produced reacted with hydrogen on catalytic materials to produce solid carbon and water thereby eliminating carbon oxide.

[0032] The pyrolysis of low-cost hydrocarbon feedstocks such as natural gas produces solid carbon and gas phase molecular hydrogen. While natural gas is used as an example, the feed gas can comprise any suitable hydrocarbon, including but not limited to, light alkanes such as methane, ethane, natural gas, alkenes, alcohols, as well as other gaseous hydrocarbons, including those that can be gasified such as the gasified or pyrolyzed products of liquid, and solid hydrocarbons (e.g. crude oil, biomass, naphtha, etc.). For example, the conversion can occur according to the following equation:

[0033] This reaction has the potential for producing a molecular hydrogen product without carbon dioxide which is a major challenge in society today. In the absence of a catalyst, the reaction requires very high temperatures (T >1000 °C) and there are many technical challenges associated with heat management in such high temperature processes. Further, the carbon product produced is typically associated with polycyclic hydrocarbon contaminants. To date there have been no significant commercial processes using pyrolysis to produce hydrogen as a primary product.

[0034] To facilitate the reaction at lower temperatures, metallic catalysts have been shown to be active including transition metals (e.g. Fe, Ni, Co) and their carbides. Catalytic pyrolysis of methane has been observed at temperatures as low' as 600 °C on the most active pyrolysis catalysts. In general, solid catalysts used for pyrolysis in fixed bed reactors rapidly deactivate as the solid carbon is deposited on the catalyst surface, thereby blocking access to the catalytic sites by the hydrocarbon and plugging the reactor. Provided sufficient hydrogen can be produced prior to catalyst deactivation, it is possible to make use of catalysts in a process that either regenerates the catalyst activity or disposes of the catalyst together with the solid carbon. n(vCH.2m )' + Active Cataly ' st - >nC sol ,id , + n *mH.2. + Inactive CatalystIf the catalyst can be replaced or regenerated at a very low cost and the hydrogen yield per unit mass of catalyst is sufficiently high such a process can be cost-effective. To date, only iron hasbeen found to have sufficiently low-cost and high hydrogen yields to be of potential use in the pyrolysis of hydrocarbons; however, with sufficient recovery the process disclosed herein can make use of other catalytic metals. A number of different solid catalyst precursors can become active catalysts. In some embodiments, the systems and processes disclosed herein make use of iron which may be introduced in various forms into the reactor under high carbon concentrations and through a process of segregation, made possible by the reactions of carbon containing molecules with iron, evolves and fragments into nanoparticulate catalysts composed primarily of iron carbide from which a solid carbon product is produced.

[0035] In some aspects, various catalysts can be used in the system for the pyrolysis of hydrocarbons. Exemplary catalysts can include catalytic components such as iron (e.g., iron oxide), nickel, cobalt, or any other suitably catalytic components. In some aspects, the catalysts used herein can be in the solid or liquid phase within the reactor. For example, nanoparticles of iron carbide can melt as low as 360 °C such that they would be in a liquid or liquid like state in a pyrolysis reactor operating at temperatures between about 750 °C to about 1000 °C. A catalyst in a liquid or liquid like state can be referred to as a condensed phase catalyst in this disclosure. The use of a condensed phase catalyst may be useful in providing a segregated fluidized bed as disclosed herein, which can provide a stratified bed within the reactor when operated under the proper conditions.

[0036] The phy sical transformation is schematically illustrated in Figure 1. As shown, the catalyst can start as a larger particle comprising an ore. an oxide, a carbide, or an elemental form of a catalyst. Depending on the source of the catalyst or catalyst precursors, other components such as silica, alumina, or the like may also be present. A dissociated carbon (e.g., a methane dissociated in contact with the catalyst, and / or one or more carbon oxides within the reactor) can contact the catalyst to form a carbide. For example, when the catalyst comprises iron, an iron carbide can be formed upon contact with a carbon under reaction conditions. Additional carbon can then form a filamentous carbon on the carbide. Once sufficient carbon has been evolved from the catalyst within a reactor, the carbon product, predominately containing a small fraction of the catalyst, is removed from the reactor as a co-product with hydrogen.

[0037] Figure 2 shows schematically the basic process 10 of hydrocarbon pyrolysis. The hydrocarbon feedstock in stream 12, which can be natural gas or other hydrocarbon, and carbon containing molecules can be pre-heated and introduced into a reactor 14 containing a catalyst where the hydrocarbon is decomposed into solid carbon and hydrogen. In some embodiments, at least one region of the reactor can comprise a fluidized bed. The solid carbon can be separated from the hydrogen and other gas phase components in a solid separation unit 16. In someembodiments, the separation occurs by entraining the carbon product in the exiting hydrogen gas stream where it is removed by way of one or more cyclones, and after cooling, bag filters. The resulting solids stream comprising carbon can form carbon stream 20. In other embodiments, the solid carbon can be removed as a separate stream from the reactor. The hydrogen can be further cooled and the heat of the gas stream can be recovered by way of a number of novel heat transfer systems as described herein. The hydrogen can be separated from other gas phase components in gas separator 118 to form the product stream 22 and any hydrocarbon containing gases can be recycled to the reactor in recycle stream 21. Heat is added to the reactor to provide the reaction energy7by way of externally heated circulating inert media.

[0038] In some embodiments, heat addition to catalytic fluidized bed reactors can be facilitated by circulating an inert media. The inert media can comprise any suitable inert, and the inert may have a size that is larger than that of the active catalyst within the reactor 31. Figure 3 illustrates schematically how externally heated coarse, high density7, inert media move towards the bottom of the reactor preheating the countercurrent upward flowing gas, and the inert media can be removed from the lower section of the reactor for reheating. In this application, novel and specific details of such a process are provided to show optimized means for producing high process energy efficiency and high hydrogen yields.

[0039] As shown in Figure 3, a heating leg or section can be used to remove a portion of the inert media from a lower portion of the reactor. The inert can pass to a heating section where the inert solids are heated by one or more means of heat addition including by not limited to chemical and electrical. In a preferred embodiment combustion gases can be introduced in the riser 46 and used to directly heat the inert media. The heated solids can then pass through a solids separator 48 to allow the combustion gases to leave the system while returning the heated inert particles to the top of the fluidized bed, thereby introducing heat into the reactor. While described as using a combustion source to directly heat the inert media, in some aspects, a heated gas can also be used. For example, an electrically heated gas such as nitrogen, carbon dioxide, or hydrogen can be passed through the riser 46 to transport and heat the inert media without the presence of any combustion.

[0040] The products within the reactor 31 can pass out of an upper section and pass through a separator 42 to produce a gaseous product stream and a solids stream comprising carbon and / or catalyst. In some aspects, a portion of the solid carbon and catalyst can be removed directly from the reactor 31 as a solids stream 44. Makeup catalyst can be introduced into the reactor directly and / or introduced with either the heated recycle stream (e.g., by7being introduced upstream of the heating leg 46) and or with the hydrocarbon feed stream 10.

[0041] The reaction conditions within the reactor 31 can comprise any suitable temperature, pressure, gas flow rate, and catalyst composition to convert at least a portion of the hydrocarbons in the feed stream 10 to solid carbon and hydrogen. In some aspects, the reactor 31 can operate at a temperature of between about 700 °C to about 1100 °C, or between about 750 °C to about 950 °C. The temperature within the reactor 31 may vary such that a temperature in a lower portion of the reactor 31 may be lower due to the incoming hydrocarbon feed stream, while the temperature in an upper portion of the reactor 31 may be higher due to the incoming inert media that has been externally heated. A conversion of the hydrocarbon within the reactor, on a single pass basis, can be between about 25% to about 95%, or between about 30% to about 85%.

[0042] Some aspects of the disclosure are illustrated in Figure 4 whereby a novel reactor concept is shown consisting of a stratified two-phase (gas-condensed phase) reactor containing at least two different solid particulate t pes; coarse, high density chemically inert particulates 49 (including but not limited to sand, silica, alumina, zirconia, silicon carbide, carbon, etc.) and smaller, low density, condensed phase catalyst nanoparticles mostly in contact with solid carbon products evolved from the catalyst. Hydrocarbon gases 40 can enter the reactor at the bottom and travel upwards with a gas velocity determined by the reactor diameter, the gas void fraction within the solid bed, and the gas flowrate. By virtue of the inert media density and the gas velocity, as determined by the reactor diameter, the denser and larger inert media returned to the reactor in stream 47 at locations near the top of the solids bed are caused to segregate to the lower zone of the reactor counter-current to the gas flow and transfer heat to the rising hydrocarbon feed stream. The relatively cool inert media are removed from the lower section through a course inert outlet 45, heated, and returned near the top of the bed.

[0043] A unique feature of the reactor is the specific design of the reactor geometry' to control the gas-solid behavior by selection of the reactor diameter such that there are at least 3 distinct zones where the gas-solid behaviors are different. In some aspects, an internal height of the reactor can be at least about 3, at least about 4, or at least about 5 times the smallest internal reactor diameter. The dense inert particles segregate to the lower region of the reactor where the diameter of the lower zone of the reactor is selected such that the gas velocity is above the minimum fluidization velocity of the inert media which are fluidized into regimes including bubbling, slugging, or turbulent within the lower zone 42, zone 1. Typically, the inert media are between 0.1 mm and 10 mm in average diameter. Whereas the coarse dense inert media segregate to the bottom, by the unique design of the reactor, the lower density, smaller carbon products containing nanoparticle catalysts are caused to accumulate near the top 44 of the reactor, zone 3. The pyrolysis reaction occurs as the hydrocarbon reactants contact the catalyst producingsolid carbon on the catalyst surface and hydrogen gas. The reactor diameter in zone 3 that is primarily composed of the carbon products containing nanoparticle catalysts is selected to be at or near the minimum fluidization velocity of these smaller, less dense particles. In one preferred embodiment the diameter is selected such that the gas velocity is below the minimum fluidization velocity' allowing a prolonged gas residence time within the zone and providing for the bed to expand as solid carbon is produced on the catalyst causing the carbon / catalyst aggregate to decrease in density and the bed void fraction to increase towards the top. The gas percolates through the expanding bed without significant fluidization. In another embodiment, the diameter of zone 3 can be set such that there is fluidization within the top pyrolysis zone, zone 3. In steadystate operation the solid carbon containing the nanoparticulate catalyst exits the reactor either through a specific solid exit stream or by entrainment with the exiting hydrogen gas stream.

[0044] The transition / segregation zone 43, zone 2, in Figure 4 will have both inert media and more dense solid catalyst that is evolving (as in Figure 1) to the nanoparticulate iron carbon composite product. The physical interactions between the inerts and the catalyst and catalyst precursors in this region under the reducing gas environment and allow for greater carbon yields per unit mass of iron. There is also a zone above the solid bed. zone 4 (46 in Fig. 4) where disengagement between the solid and gas is caused to occur.

[0045] Another schematic of the reactor is shown in Figure 5. The operation of this reactor can be the same or similar to that shown in Fig. 4. In addition, the inert particles existing from the lower zone and returning into the disengagement zone and / or the catalytic pyrolysis zone can be heated in a separate heating section such as that shown in FIG. 3. Other heating sections can also be used.

[0046] An integrated process for production of hydrogen and carbon from natural gas is shown as a process flow diagram in Figure 6. The pyrolysis subsystem can include any of those shown in Figures 2-5. As shown, the natural gas feed 1 can be combined with a recycle stream 24 to form stream 3, which can be preheated through a cross exchanger 61 using heat from the product gases in stream 10. The resulting heated stream 4 can enter the two-phase reactor 62 where carbon and hydrogen can be produced. The two-phase reactor 62 can be heated by circulating coarse inert material, such as sand, in stream 5 A which is heated by combustion of a small fraction of the hydrogen product or other fuel in combustor 63 as shown in Figure 7. The combustor 63 can heat the inert material to between about 900 °C to about 1,100 °C, or between about 900 °C to about 1,000 °C, or to about 950 °C, using a combustion temperature of approximately 2,000 °C. The heated combustion gases in stream 34 can pass to a steam generator to produce high quality steam in stream 40. The remaining hot combustion cases in stream 36can be used to pre-heat the oxidant to up to 700 °C to allow the combustor to reach high temperatures. The heated inert material can return to the reactor 62 in stream 5B.

[0047] The resulting product gases in stream 8 leaving the separator 64 can be used to generate steam in stream 13 while also heating the combined feed stream 3 to a temperature of at least about 250 °C, at least about 300 °C, at least about 350 °C, or at least about 400 °C.

[0048] The solid carbon in stream 7, in one embodiment, can be removed from the reactor 62 in the product gas stream 6 and removed by a cyclone 64, however, in other embodiments the carbon may leave the reactor through a separate solids outlet. An advantage of the process shown in Figure 6 is the heat integration with high quality steam production from the high temperature reactor exit and the combustion gases which provides for high energy efficiency.

[0049] As part of the system, combustion gases can be contacted with the coarse inerts to provide heat for the reactor. One exemplary embodiment of a combustion system is shown in Figure 7. The combustion system shown in Figure 7 can be used as the combustor 63 of Figure 6 in some embodiments. The combustion system 63 can comprise a vessel / firebox at similar pressure as the pyrolysis reactor and operating at higher temperature than the pyrolysis reactor. Inert particles in stream 5 A can be heated as they move through the combustor 63. The residence time of particle can be controlled by placing internals, such that particles achieve the required temperature. The flame temperature can be kept as hot as possible to minimize heat loss with flue gas, to achieve high hydrogen yield from the process. Combustor internals are designed to induce natural draft w ithin vessel to make the temperature more uniform. The flame temperature can be as high as 2,000 °C while the circulation can maintain the combustor at a temperature between about 800 °C to about 1,100 °C, or between about 950 °C to about 1,000 °C. The internals are designed such that particles are not exposed to high temperature of the flame, and to avoid short circuiting of hot gases within combustion chamber. The hot solids are collected at the bottom of the combustor from where they are conveyed to the pyrolysis reactor using the same flue gas exiting the combustion chamber.

[0050] As shown in Figure 7, a central combustion section can be used to combust the incoming gases. An internal circulation channel can be used to maintain an even temperature within the combustor 63. The inert material in stream 5 A can fall through a series of plates or channels to allow the combustion gases to contact and heat the inert material within the combustor 63. As the inert material falls to the bottom of the combustor under the effects of gravity, the flue gases can be used to fluidized and carry the inert material upwards in stream 5B to an upper section f the reactor. A separator can be used at an upper point in the fluidized channel to separate the flue gases entraining the inert material from the solid inert material.

[0051] As described herein, heat addition to catalytic fluidized bed reactors can be facilitated by circulating an inert media. Figure 8 shows a block diagram of a system 80 along with a corresponding process using combustion gases to heat the inert media and then pass the combustion gases to a second reactor where the carbon oxides are converted to solid carbon. In this process, a hydrocarbon feed stream 81 can be passed to a pyrolysis reactor 82. The pyrolysis reactor can operate in the absence or substantial absence of oxygen, and can be any of the pyrolysis reactor as described herein. For example, the pyrolysis reactor 82 can be the same or similar to the reactor 14 of Figure 2, or the pyrolysis reactors of Figures 3-5. With the pyrolysis reactor 82, inert material can circulate with catalytic material, and the two solid phases can stratify within the pyrolysis reactor 82 as described herein. The resulting product can comprise solid carbon along with some amount of the catalyst, hydrogen, and some amount of unreacted hydrocarbons can be present in the outlet stream. The product stream can pass to a solid separator 83 wherein a solid stream 93 comprising the carbon and some amount of catalyst can leave the system 80. The remaining gases can pass to a gas separator 84 to produce a hydrogen product stream 94 and a recycle stream 95 comprising at least a portion of the unreacted hydrocarbons.

[0052] During the reaction in the pyrolysis reactor 82, the inert material can pass from the pyrolysis reactor 82 to a combustor 86. Within the combustor 86, a gas (e.g., a fuel gas inlet stream 88) can be combusted and the resulting flue gases can directly contact the inert material as described herein. The heated inert material can pass back to the pyrolysis reactor 82 to introduce heat into the pyrolysis reactor and allow the pyrolysis reaction to occur. The combustion of the heating gases w ithin the combustor 86 can result in the formation of carbon oxides such as carbon dioxide and carbon monoxide and / or other oxygen containing gases such as water. The combustion gases can then pass as stream 89 into a carbon formation reactor along with a feed stream of hydrogen 90, and optionally, some amount of unreacted hydrocarbons from the combustor 86. Within the carbon formation reactor 87, the carbon oxides can react with the hydrogen and / or hydrocarbons to form solid carbon and water in the presence of a catalyst. The solid carbon can be separated from the products and pass out of the system as a solid carbon stream 92, which can comprise some amount of catalyst as described herein. A product gas stream comprising water can pass out as stream 91. Some portion of unreacted gases can also pass out with the w ater stream 91 in some aspects.

[0053] The reactions occurring within the carbon formation reactor 87 can be both exothermic and endothermic. The reaction conditions within the carbon formation reactor 87 may include a pressure of between about 1 bar to about 50 bar. or between about 1 bar to about 20 bar, a temperature of about 400 °C to about 1000 °C, or between about 500 °C to about 750 °C. Thetemperature within the reactor may be maintained by providing an adiabatic reactor vessel and / or providing the reactants at the desired temperature into the reactor to maintain the temperature within the desired temperature range. The carbon formation reactor 87 can take a variety of forms such as a fixed bed reactor, a fluidized bed reactor, a moving bed reactor, or the like.

[0054] The carbon formation reactor 87 can use a catalyst to promote the reactions and the formation of solid carbon. The catalyst material can include any material suitable for catalyzing the formation of the solid carbon material from the carbon oxide and the gaseous reducing material. As an example, the catalyst material may be an element of Group VI, Group VII, Group VIII, Group IX, or Group X of the Periodic Table of Elements (e.g., iron, nickel, molybdenum, platinum, chromium, cobalt, tungsten, etc.), an actinide, a lanthanide, oxides thereof, alloys thereof, or combinations thereof. Any metal known to be subject to metal coking may also be suitable for use as the catalyst material.

[0055] The catalyst material may be provided within the carbon formation reactor 87 (e.g., within the reaction chamber) as one or more solid structures (e.g., a particle, a wafer, cylinder, plate, sheet, sphere, pellet, mesh, fiber, etc.), and / or as at least a partial coating on another structure (e.g., particles of the at least one material deposited on a structure, such as a wafer, cylinder, plate, sheet, sphere, mesh, pellet, etc.) within the reactor vessel. In some embodiments, the catalyst material may be provided w ithin the reactor as a plurality' of particles or particulates. The catalyst material may be stationary (e.g. , as a catalyst bed) or mobile (e.g., as a fluidized bed) within the reactor. In some embodiments, a portion of the catalyst material may be mobile within the reactor and another portion of the catalyst material may be stationary within the reactor.

[0056] As an example, the catalyst for the carbon formation reaction can include an iron-based catalyst. While not intending to be limited by theory', a dissociated carbon (e.g., a methane dissociated in contact with the iron, and / or one or more carbon oxides within the reactor) can contact the iron (e.g., a ferrite) within the catalyst to form an iron carbide. The iron carbide can then dissociate to reform the ferrite along with a layer of carbon (e.g. , graphite, etc.) on the ferrite. The process can continue and result in the buildup of carbon lay ers on the ferrite, where the reaction rate can decrease as the thickness of the carbon layer on the iron builds due to increased diffusion resistance to the reactive iron core. The catalyst may then deactivate upon the buildup of a sufficient carbon layer.

[0057] The formation of the solid carbon then occurs on or around the catalyst such that the removal of solid carbon from the reactor vessel (e.g., using a separator such as a cyclone, settling chamber, etc.) can also result in the removal of the catalyst from the reactor. As a result, a small amount of catalyst may be introduced into the carbon formation reactor 87 along with thereactants while a corresponding amount of catalyst may be removed with the solid carbon. In some aspects, the amount of catalyst added into the reactor may have a mass ratio of catalyst to reactants of between about 0.0001 : 1 to about 1 : 1 , or between about 0.001 : 1 to about 0.1 : 1.

[0058] The conditions and catalyst of the pyrolysis reaction in the pyrolysis reactor 82, the conditions within the combustor 86, and the catalyst and the catalyst and conditions with the carbon formation reactor 87 can all be the same as or similar to the corresponding conditions described herein.

[0059] Figure 9 shows another configuration for an integrated pyrolysis process such that air instead of pure oxygen can be utilized. The system and process shown in Figure 9 is similar to the system and process of Figure 8, and the common elements can be the same or similar to those described herein. As shown in Figure 9, the hydrocarbon feed stream 81 can comprise any of the hydrocarbons described herein, and the stream can be split into two portions 101A, 101B. The first portion in stream 101 A can pass to the pyrolysis reactor 82 where the hydrocarbon can react to form solid carbon and hydrogen. The solids can be separate, and the product gases can pass to a gas separator 84 to produce a hydrogen product stream 94 and a separated stream 104 comprising at least a portion of the unreacted hydrocarbons. The separated stream 104 can pass to the carbon formation reactor 87.

[0060] During the reaction in the pyrolysis reactor 82, the inert material can pass from the pyrolysis reactor 82 to a combustor 86 in stream 85 A. Within the combustor 86, a gas (e.g., the second portion 101B of the hydrocarbon feed stream 81) can be combusted and the resulting flue gases can directly contact the inert material as described herein. The heated inert material can pass back to the pyrolysis reactor 82 in stream 85B to introduce heat into the pyrolysis reactor and allow' the pyrolysis reaction to occur. The combustion of the heating gases within the combustor 86 can result in the formation of carbon oxides such as carbon dioxide and carbon monoxide and / or other oxygen containing gases such as water.

[0061] Depending on the composition of the source of oxygen used to combust the hydrocarbon or hydrogen in the combustor 86, some addition gases such as nitrogen may be present in the flue gas stream 89. When present, a separator 109 can be used to separate the carbon oxides such as carbon dioxide or carbon monoxide from the inert gases such as nitrogen. A purge gas stream 106 comprising nitrogen or other inert or non-reacted gases can be separated from the flue gas stream 89 and passed out of the system. In some aspects, the purge gas stream 106 can pass through one or more heat exchanges to extract heat from the purge gas stream 106 prior to passing the purge gas stream 106 out of the system. The remaining stream 105 can comprise primarily the carbon oxides can pass to the carbon formation reactor 87. Within the carbon formationreactor 87, the carbon oxides in stream 105 can react with the hydrogen and / or hydrocarbons in the separated stream 104 as well as an optional external carbon dioxide stream 107 to form solid carbon and water in the presence of a catalyst, which can pass out of the carbon formation reactor as stream 108. The solid carbon can be separated from the products and pass out of the system, where the solid carbon can comprise some amount of catalyst as described herein. The product stream can be passed through one or more heat exchangers as described herein in order to extract heat and / or generate steam for use in the system.

[0062] The conditions and catalyst of the pyrolysis reaction in the pyrolysis reactor 82, the conditions within the combustor 86, and the catalyst and the catalyst and conditions with the carbon formation reactor 87 can all be the same as or similar to the corresponding conditions described herein. Within the system as shown in Figure 9, the hydrocarbon feed stream 81 or any portion thereof (e.g., stream 101A and / or stream 101B) can be pre-heated to at least about 300 C, at least about 350 C, or at least about 400 C. Within the combustor 86, the oxidant stream 102 can be air or any oxy gen enriched stream. An oxy gen enriched stream refers to any stream having an oxygen concentration greater than the atmospheric concentration of oxygen. The oxygen stream can be obtained at a desired purity from an oxygen storage tank, or via an oxygen enrichment process, for example, the separation of air into nitrogen and oxygen, such as pressure swing adsorption (PSA), vacuum swing adsorption (VSA), or cryogenic separation techniques. The oxygen in the oxygen stream may have at least about 70 vol%, at least 80 vol%, or at least 90 vol % oxygen (e.g.. 90. 91. 92, 93, 94, 95, 96, 97, 98, 99, 99.1, 99.2, 99.3. 99.4. 99.5. 99.6, 99.7, 99.8, 99.9, or 100 vol % oxygen).

[0063] In some aspects, the oxidant stream 102 can comprise oxygen (e.g., from an oxygen enriched stream) combined with a portion of the flue gas from stream 89 or stream 105, which can allow for the flame temperature to be controlled without introducing additional inert gases such as nitrogen. For example, the oxidant stream 102 can comprise between about 50 vol.% to about 70 vol.% oxygen with the remainder being a recycled portion of the flue gas stream. The resulting oxidant stream 102 can be approximately 20 vol.% oxygen entering the combustor 86. The oxidant stream 102 can be pre-heated to between about 600 °C to about 800 °C, or between about 650 °C to about 750 °C. As described herein, the resulting flame temperature can be around 2000 °C while keeping the gases contacting the inert media to around 1000 °C.

[0064] Figure 10 illustrates another configuration for generating hydrogen with the concurrent removal of carbon oxides. The system of Figure 10 is similar to the system of Figure 9, and the similar elements will not be redescribed in the interest of brevity. The main difference between the system of Figure 10 and that in Figure 9 is the use of an oxygen enriched stream as the oxidantstream 103 entering the combustor 86. The use of an oxygen enriched stream can reduce or avoid the presence of inert gases, thereby allow ing the separator 109 of Figure 9 to be avoided. It can be noted that some amount of inert gases can be present in the oxidant stream 103, and the inert gases can pass to the carbon formation reactor 87 and pass out with the product gases. The inert gases can then be separated from the downstream solid carbon and water streams leaving the carbon formation reactor 87.

[0065] Another embodiment of a pyrolysis reactor is shown in Figure 11 where the segregation of coarse inert media and fine catalyst is achieved outside the fluidized bed 115 and the reactor 31. One way of achieving this segregation is via series of separators such as cyclones. In this design the solids are withdrawn from the fluidized bed 115 in which pyrolysis occurs and passed through single or multiple cyclones in series. Preheated hydrocarbon feed to the reactor 31 can be used as a motive gas in these cyclones. Coarse inert media can travel to the combustor chamber in a heating section, w hile fine catalyst can be sent back for pyrolysis in the reactor 31. The reactor 31 can operate at any of the conditions disclosed herein for the pyrolysis reactor.

[0066] As shown in Figure 11, a first portion of the hydrocarbon feed stream 10 can pass into the reactor 31, which comprise a fluidized bed comprising inert media, solid carbon, and catalyst as described herein. A portion of the solids can pass out of a lower portion of the reactor 31 using various non-mechanical valve configurations assisted by a gas stream 111, which can comprise a portion of the hydrocarbon feed 10. In some aspects, the non-mechanical valve can enable movement of the solid particulates while providing isolation of the gases. Examples of non- mechanical valves can include a loop seal or an L-valve may also be used as a non-mechanical valve.

[0067] The solid stream can be fluidized and passed to a separator 112 such as a cyclone. In some aspects, the cyclone can comprise a classifier cyclone that can selectively pass particles of a certain size as a solids stream 85 A out of the separator 112, while the remaining solids can pass with the gas stream 114 back to fluidized bed 115 within the reactor 31. This can allow the inert particles to be selectively separated and passed to a heating sect on in the solids stream 85 A while the remaining catalyst particles and carbon entrained in the stream from the reactor 31 back into the reactor 31 without passing to the heating section. Once heated in the heating section, the inert media can pass back into the reactor 31 as stream 85B. In some aspects, the inert media can pass back into an upper portion of the reactor 31 above the fluidized bed 115, though in some aspects, the heated inert media in stream 85B can also pass directed back into the fluidized bed 115.

[0068] The smaller particles in the fluidized bed 115 can pass to an upper portion of the reactor 31 having an increased diameter, and as a result, a lower gas velocity, to allow any entrainedinert media to return to the fluidized bed 115. The smaller particles can comprise the solid carbon and some amount of catalyst particles that have degraded into small particles. The smaller particles can be entrained with the gas stream once their size is reduced sufficiently. The outlet stream 113 can pass out of the reactor 31 and pass to a separation system. In some embodiments, one or more separators such as cyclones can be used in parallel or series to separate any solids from the outlet stream 113. As shown in Figure 11, a first separator 116 can be used to separate any larger particles of the inert media and / or catalyst for return to the reactor 31. The smaller carbon and catalyst can pass through the separator 116 w ith the gas stream to a second separator 117 such as a cyclone. The second separator 117 can be used to separate all or substantially all of the solids particles from the gas stream to produce a first product stream 119 comprising the solid particles such as the solid carbon and catalyst, and a second product stream 118 comprising solid carbon and catalyst.

[0069] An exemplary performance of the process as described herein in terms of hydrogen yield, consumed power, and efficiency of pyrolysis at different extent of feed heat integration is shown in Figure 12. As shown, the hydrogen yield increases with increasing hydrocarbon feed temperature due to preheating as well as increased oxidant stream temperature due to pre-heating. Heat integration can be used a way to use the heat of the product gases and flue gases to preheat the hydrocarbon feed and / or air for combustion. High heat integration significantly improves the hydrogen yield. The hydrogen yield is defined as the ratio of hydrogen as product and the amount of hydrogen present in the feed. This process can use both methane and hydrogen as fuel for pyrolysis reaction. For well heat integrated processes hydrogen yield can be near 0.7. The results further demonstrate that the use of a carbon formation reactor within the system can be used to produce additional heat that can be converted to steam. This process produces excess steam for electricity generation. This can reduce the net power consumption below 1 kWh / kg of hydrogen. The results presented in Figure 12 are based on the use of an oxygen enriched stream. The use of air would reduce the efficiency of the system due to compression costs for the air, which can lead to an additional net power consumption of up to 1.5 kWh / kg of hy drogen.

[0070] Figure 13 shows criteria affecting the segregation of particles within a fluidized bed. The criterion uses gas velocity, minimum fluidization velocity, and density of dispersed and continuous phase. This criterion informs what fraction of solids will stay segregated. As a specific example, Figure 14 show's a table illustrating a sample calculation for segregating a bed with iron particle of 200 microns with minimum fluidization velocity of 0.02 m / s and inert sand particle of 1000 microns with minimum fluidization velocity of 0.23 m / s. With this configuration if the pyrolysis bed is operated at 0.25m / s, about 57% of the bed will be segregated (as per Figure13). The fluidization regime map presents the fluidization regime when the pyrolysis bed is operated with 0.25 m / s gas superficial velocity, and iron and sand particle of above-mentioned diameter. In some aspects, the gas velocity can be selected to allow the fluidized bed to operate within a fluidization regime for pyrolysis as a bubbling fluidized bed. One of ordinary skill in the art having the benefit of this disclosure and the criteria presented herein would understand how to select a gas velocity through the fluidized bed to operate within a desired fluidization regime.

[0071] Figure 15 presents the ratio of inert media to that of flue gas in the heating section. This can be an important criterion to allow7the flue gas to convey the inert media from combustion chamber (e g., the heating section or combustor as described herein, etc.) to the pyrolysis bed in the reactor. In some aspects, a solid to gas mass flow ratio can be less than, or less than or equal to, about 20. By operating at an approach temperature range of about 100 °C, the solid to gas mass flow ratio can be -13. This ensures stable circulation of solids in the system. As used in this section, the approach temperature represents a temperature differential betw een the operating temperature of the fluidized bed and the inlet temperature of the inert media entering the reactor.

[0072] Figure 16 shows another configuration of a heat integration scheme applied around the pyrolysis reactor. The configuration of Figure 1 is similar those described herein, and the like components will not be redescribed in the interest of brevity7. In this configuration, a small stream 161 of solids (inert media and / or catalytic particle) can be withdrawn from the pyrolysis zone 44. The solids can be circulated in counter-current contact with cold hydrocarbon feed 10 in a preheating zone 162. The hot solids in stream 161 can exchange heat with cool hydrocarbon feed 10 to cool the solids while heating the hydrocarbons in the hydrocarbon feed stream 10. The flowrate of the solids in stream 161 can be chosen such that temperature of the solids in stream 163 exiting the preheating zone 162 can be approximately equal to the incoming hydrocarbon feed stream 10. Here, a part of cold solids in stream 163 can optionally be removed as a solid product stream 164A. The remaining cold solids in stream 164B can be conveyed up to a heat recover zone 165. As shown the cold solids in stream 164B can first pass through a separator 166 to separate a transport gas used to pneumatically convey the cold solids in stream 164B within the system. In the heat recovery zone 165, the cold solids can be contacted in counter current flow with the hot product gases in stream 113 coming from pyrolysis reactor. In the heat recovery7zone 165, the solids can be heated by heat transferred from the outgoing gases in stream 113, and the heated solids can be fed to the pyrolysis bed in the reactor as solids stream 166. In some aspects, the raw material used to form the catalyst, or the catalyst itself in stream 168 can optionally be introduced into the heat recovery7zone 165 to preheat the catalyst prior to passingthe catalyst into the reaction zone. The cooled product gases can then leave the system as stream 167. This configuration can capture heat from the product gases in stream 113 so that the heat is recovered back to preheat the feed using the solids in stream 166 as a heat transport mechanism. It is likely that some pyrolysis can happen in the feed preheating zone and the catalytic solids can gather the resulting carbon. The use of the catalyst solids can help to avoid any buildup of carbon product in the heat recovery zone 165 or the feed preheating zone 162.

[0073] As described herein, various systems and methods can allow for heat integration along with a system that can produce hydrogen while reducing or avoiding any discharge of carbon oxides generated within the system. This can provide a number of advantages within the system. For example, the use of a multi -zone reactor configured to provide different gas phase velocities can be useful in providing size / density stratification using a segregated, multiple zone reactor with flow characteristics determined by the gas velocity and reactor dimensions. The multiple zones can allow for the use of an inert material along with a catalytic material to generate solid carbon and hydrogen in a single reactor. The integrated, continuous process can incorporate the stratified reactor, and / or a homogeneous fluidized bed reactor heated with circulating solids can also be used. Within this system, a condensed phase catalyst which can be all solid but may be all or partially liquid can be used. The catalyst can, in some aspects, include iron carbide nanoparticles. It should be noted that the nanoparticulate catalyst may be liquid or liquid-like. For example, nanoparticles of Fe carbide can melt as low as 360 °C. The various heat integration schemes can also be applied using the pyrolysis reactor and the surrounding systems to provide an efficient system.

[0074] Having described various processes, systems, compositions, and methods, certain aspects can include, but are not limited to:

[0075] In a first aspect, a chemical reactor for converting hydrocarbons gases to solid carbon and hydrogen products comprises: a reactor vessel comprising a first inlet for hydrocarbon gases, a second inlet for catalyst or catalyst precursors, a third inlet for inert media, one or more first outlets for product gases, and product solids with catalyst, or both, and one or more second outlets for inert media; wherein a diameter of the reactor vessel varies along a height of the reactor vessel, wherein the diameter of the reactor vessel defines at least three distinct zones each having different diameters, where the at least three distinct zones are configured to have different gassolid interactions based on the different diameters, and wherein the diameter is configured to control a gas velocity within the reactor vessel to control gas-solid interactions within the reactor to allow varying degrees of fluidization of the solids within the reactor vessel; and a bed of particulates disposed within the reactor vessel, wherein the bed of particulates comprises catalystparticles, solid carbon, and inert media in a stratified arrangement, wherein the bed of particulates is configured to become partially or wholly segregated under the influence of gases flowing upwards through the reactor vessel.

[0076] A second aspect can include the chemical reactor of the first aspect, further comprising: a heating section in fluid communication with the reactor vessel, wherein the heating section comprises a heating leg configured to receive inert media from the reactor vessel, receive a combustion gas and an oxidant gas, combust the combustion gas with the oxidant gas to heat the inert media and produce heated inert media, and return the heated inert media to the reactor vessel.

[0077] A third aspect can include the chemical reactor of the first or second aspect, wherein the heating section if configured to receive inert media from a lower zone of the reactor vessel and return the heated inert media to an upper zone of the reactor vessel.

[0078] A fourth aspect can include the chemical reactor of any one of the first to third aspects, wherein the height of the reactor vessel is at least 5 times the minimum diameter of the reactor vessel.

[0079] A fifth aspect can include the chemical reactor of any one of the first to fourth aspects, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0080] A sixth aspect can include the chemical reactor of any one of the first to fifth aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

[0081] A seventh aspect can include the chemical reactor of any one of the first to sixth aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0082] An eighth aspect can include the chemical reactor of any one of the first to seventh aspects, wherein the inert media has a larger particle size than a particle size of the solid carbon containing the catalyst or catalyst precursors.

[0083] A ninth aspect can include the chemical reactor of any one of the first to eighth aspects, wherein a first zone of the at least three zones comprises a lower zone, wherein the lower zone has a smaller diameter than any other zone of the at least three zones, and wherein the lower zone is at least 50 wt.% of the inert media in the bed of particulates.

[0084] A tenth aspect can include the chemical reactor of any one of the first to ninth aspects, wherein a second zone of the at least three zones comprises a pyrolysis zone, wherein the pyrolysis zone has a larger diameter than a zone of the at least three zones having a smallestdiameter, and wherein the pyrolysis zone has a smaller diameter than a zone of the at least three zones having a largest diameter, wherein the pyrolysis zone comprises at least 50 vol% catalyst or catalyst precursors in the bed of particulates.

[0085] An eleventh aspect can include the chemical reactor of any one of the first to tenth aspects, wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a larger diameter than any other zone of the at least three zones, and wherein the disengagement zone has less than 20 vol.% solids.

[0086] A twelfth aspect can include the chemical reactor of any one of the first to tenth aspects, wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a smaller diameter than a zone directly below the third zone.

[0087] A thirteenth aspect can include the chemical reactor of any one of the first to twelfth aspects, wherein the catalyst or catalyst precursors are in a condensed phase.

[0088] In a fourteenth aspect, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises: passing a feed gas comprising hydrocarbon gases into a reactor vessel, wherein the reactor vessel comprises a first inlet for hydrocarbon gases, a second inlet for catalyst or catalyst precursors, a third inlet for inert media, and a first outlet for product gases and product solids with catalyst, and a second outlet for inert media, wherein a diameter of the reactor vessel varies along a height of the reactor vessel, and wherein the diameter of the reactor vessel defines at least three distinct zones each having different diameters, passing the feed gas through a bed of particulates disposed within the reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media in a stratified arrangement, forming solid carbon and hydrogen as the feed gas passes through the bed of particulates; and stratifying the bed of particulates in response to passing the feed gas through the bed of particulates, wherein the bed of particulates partially or wholly segregates under the influence of the feed gas flowing upwards through the reactor vessel.

[0089] A fifteenth aspect can include the process of the fourteenth aspect, further comprising: passing a portion of the inert media from the reactor vessel to a heating section; contacting a heating gas with the inert media to produce heated inert media; and passing the heated inert media back to the reactor vessel.

[0090] A sixteenth aspect can include the process of the fourteenth aspect, further comprising: combusting a combustion gas in the heating section to produce combustion products, wherein the heating gas comprises the combustion products.

[0091] A seventeenth aspect can include the process of any one of the fourteenth to sixteenth aspects, wherein the heating section receives inert media from a lower zone of the reactor vessel and returns the heated inert media to an upper zone of the reactor vessel.

[0092] An eighteenth aspect can include the process of any one of the fourteenth to seventeenth aspects, wherein the height of the reactor vessel is at least 5 times the minimum diameter of the reactor vessel.

[0093] A nineteenth aspect can include the process of any one of the fourteenth to eighteenth aspects, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0094] A twentieth aspect can include the process of any one of the fourteenth to nineteenth aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

[0095] A twenty first aspect can include the process of any one of the fourteenth to twentieth aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0096] A twenty second aspect can include the process of any one of the fourteenth to twenty first aspects, wherein the inert media has a larger particle size than a particle size of the solid carbon containing the catalyst or catalyst precursors, and wherein the catalyst or catalyst precursors segregate from the inert media based on differences in size and density.

[0097] A twenty third aspect can include the process of any one of the fourteenth to twenty second aspects, wherein a first zone of the at least three zones comprises a lower zone, wherein the lower zone has a smaller diameter than any other zone of the at least three zones, and wherein the lower zone is at least 50 wt.% of the inert media in the bed of particulates.

[0098] A twenty fourth aspect can include the process of any one of the fourteenth to twenty third aspects, wherein a second zone of the at least three zones comprises a pyrolysis zone, wherein the pyrolysis zone has a larger diameter than a zone of the at least three zones having a smallest diameter, and wherein the pyrolysis zone has a smaller diameter than a zone of the at least three zones having a largest diameter, wherein the pyrolysis zone comprises at least 50 vol% catalyst or catalyst precursors in the bed of particulates.

[0099] A twenty fifth aspect can include the process of any one of the fourteenth to twenty fourth aspects, wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a larger diameter than any other zone of the at least three zones, and wherein the disengagement zone has less than 20 vol.% solids.

[0100] A tw enty sixth aspect can include the process of any one of the fourteenth to twenty fifth aspects, wherein the catalyst or catalyst precursors are in a condensed phase.

[0101] In a twenty seventh aspect, an integrated system for converting hydrocarbons gases to solid carbon and hydrogen products comprises: a preheater configured to exchange heat between a feed stream of hydrocarbon gases and reaction product gases; a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media, wherein the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for heated inert media particles near a top of the bed of particulates, an outlet for the inert media near a bottom of the bed of particulates; a heating section in fluid communication with the pyrolysis reactor, wherein the heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet; a separator system in fluid communication with the pyrolysis reactor through the product gas outlet, where the separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor: and a heat exchanger configured to remove heat from the reaction product gases exiting the pyrolysis reactor.

[0102] A tw enty eighth aspect can include the integrated system of the twenty' seventh aspect, further comprising: a gas absorber-separation system in fluid communication with the pyrolysis reactor, wherein the gas absorber-separation system is configured to separate hydrogen gas from the reaction product gases.

[0103] A twenty ninth aspect can include the integrated system of the twenty seventh or twenty eighth aspect, wherein the separator system comprises one or more cyclone separators.

[0104] A thirtieth aspect can include the integrated system of any one of the twenty seventh to twenty ninth aspects, wherein the height of the reactor vessel is at least 5 times the minimum diameter of the reactor vessel.

[0105] A thirty first aspect can include the integrated system of any one of the twenty seventh to thirtieth aspects, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0106] A thirty second aspect can include the integrated system of any one of the twenty seventh to thirty first aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

[0107] A thirty third aspect can include the integrated system of any one of the twenty seventh to thirty second aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0108] A thirty fourth aspect can include the integrated system of any one of the twenty seventh to thirty third aspects, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

[0109] A thirty fifth aspect can include the integrated system of any one of the twenty seventh to thirty fourth aspects, wherein a first zone of the at least three zones comprises a lower zone, wherein the lower zone has a smaller diameter than any other zone of the at least three zones, and wherein the lower zone is at least 50 wt.% of the inert media in the bed of particulates.

[0110] A thirty sixth aspect can include the integrated system of any one of the twenty seventh to thirty fifth aspects, wherein a second zone of the at least three zones comprises a pyrolysis zone, wherein the pyrolysis zone has a larger diameter than a zone of the at least three zones having a smallest diameter, and wherein the pyrolysis zone has a smaller diameter than a zone of the at least three zones having a largest diameter, wherein the pyrolysis zone comprises at least 50 vol% catalyst or catalyst precursors in the bed of particulates.

[0111] A thirty seventh aspect can include the integrated system of any one of the twenty seventh to thirty7sixth aspects, wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a larger diameter than any other zone of the at least three zones, and wherein the disengagement zone has less than 20 vol.% solids.

[0112] A thirty eighth aspect can include the integrated system of any one of the twenty seventh to thirty7seventh aspects, wherein the catalyst or catalyst precursors are in a condensed phase.

[0113] In a thirty ninth aspect, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises: heating a feed stream to produce a heated feed stream by exchanging heat between the feed stream and a reaction product gas stream, wherein the feed stream comprises hydrocarbon gas; passing the heated feed stream to a pyrolysis reactor, wherein the pyrolysis reactor comprises a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media; contacting the heated feed stream with the catalyst particles to form reaction products comprising solid carbon and hydrogen from the hydrocarbon gas; removing a portion of the inert media from the bed of particulates during the contacting; heating the inert media removed from the bed of particulates in a heating section to form heated inert media; passing the heated inert media back to the bed of particulates; separating the reaction products to form a solid carbon product and a gaseous product; and extracting heat from the reaction products downstream of the pyrolysis reactor.

[0114] A fortieth aspect can include the process of the thirty ninth aspect, further comprising: separating a hydrogen gas stream from the reaction products downstream of the pyrolysis reactor.

[0115] A forty first aspect can include the process of the thirty ninth or fortieth aspect, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0116] A forty second aspect can include the process of any one of the thirty ninth to forty first aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

[0117] A fort}7third aspect can include the process of any one of the thirty' ninth to forty' second aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0118] A forty fourth aspect can include the process of any one of the thirty’ ninth to forty third aspects, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

[0119] A forty fifth aspect can include the process of any one of the thirty ninth to forty third aspects, wherein the pyrolysis reactor operates at a temperature between about 750 °C to about 1,000 °C.

[0120] A forty' sixth aspect can include the process of any one of the thirty' ninth to forty' fifth aspects, wherein heated feed stream flows through the bed of particulates at a flow rate sufficient to form a fluidized bed within at least a portion of the reactor vessel.

[0121] A forty seventh aspect can include the process of any one of the thirty ninth to forty sixth aspects, further comprising: stratifying the bed of particulates in response to passing the heated feed gas through the bed of particulates, wherein the bed of particulates partially or w holly segregates under the influence of the heated feed gas flowing upwards through the reactor vessel.

[0122] In a forty eighth aspect, an integrated system for converting hydrocarbons gases to solid carbon and hydrogen products comprises: a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media, wherein the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for heated inert media particles near a top of the bed of particulates, an outlet for the inert media near a bottom of the bed of particulates; a heating section in fluid communication with the pyrolysis reactor, wherein the heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet; and a carbon formation reactor in fluid communicationwith an outlet of the heating section, wherein the carbon formation reactor is configured to receive the hot gas stream from the heating section and convert at least a portion of carbon oxides in the hot gas stream to solid carbon and water.

[0123] A forty ninth aspect can include the integrated system of the forty eighth aspect, further comprising: a feed gas inlet into the carbon formation reactor, wherein the feed gas inlet is configured to receive a hydrogen or hydrocarbon stream for the conversion of at least the portion of carbon oxides in the hot gas stream to the solid carbon and the water.

[0124] A fiftieth aspect can include the integrated system of the forty eighth or forty ninth aspect, wherein the carbon formation reactor comprises a carbon formation catalyst, and wherein the carbon formation catalyst comprises an element of Group VI, Group VII, Group VIII, Group IX. or Group X of the Periodic Table of Elements, an actinide, a lanthanide, oxides thereof, alloys thereof, or combinations thereof.

[0125] A fi ty first aspect can include the integrated system of any one of the forty eighth to fiftieth aspects, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0126] A fifty second aspect can include the integrated system of any one of the forty eighth to fifty first aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

[0127] A fifty third aspect can include the integrated system of any one of the forty eighth to fifty second aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0128] A fifty fourth aspect can include the integrated system of any one of the forty' eighth to fifty third aspects, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

[0129] In a fifty fifth aspect, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises: passing a feed stream through a bed of particulates in a reactor vessel, wherein the feed stream comprises hydrocarbon gas, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media; forming a product stream within the reactor vessel based on reacting the feed stream with the catalyst particles, wherein the product stream comprises solid carbon and hydrogen; passing a portion of the inert media from the reactor vessel to a heating section; combusting a combustion gas in the heating section to produce combustion products, wherein the combustion products comprise carbon oxides; contacting the combustion products with the inert media to produce heated inert media; passing the combustionproducts to a carbon formation reactor: and converting at least a portion of the carbon oxides in the combustion products to solid carbon within the carbon formation reactor.

[0130] A fifty sixth aspect can include the process of the fifty fifth aspect, further comprising: passing a hydrogen or hydrocarbon stream into the carbon formation reactor during the converting to form the solid carbon and water.

[0131] A fifty' seventh aspect can include the process of the fifty fifth or fifty sixth aspect, wherein the carbon formation reactor comprises a carbon formation catalyst, and wherein the carbon formation catalyst comprises an element of Group VI, Group VII, Group VIII, Group IX, or Group X of the Periodic Table of Elements, an actinide, a lanthanide, oxides thereof, alloys thereof, or combinations thereof.

[0132] A fifty eighth aspect can include the process of any one of the fifty fifth to fifty seventh aspects, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0133] A fifty' ninth aspect can include the process of any one of the fifty fifth to fifty' eighth aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

[0134] A sixtieth aspect can include the process of any one of the fifty fifth to fifty ninth aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0135] A sixty first aspect can include the process of any one of the fifty fifth to sixtieth aspects, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

[0136] A sixty' second aspect can include the process of any one of the fifty fifth to sixty' first aspects, wherein the carbon formation reactor operates at a temperature between about 400 °C and about 1000 °C.

[0137] A sixty third aspect can include the process of any one of the fifty fifth to sixty' second aspects, wherein the carbon formation reactor operates as a fluidized bed reactor.

[0138] In a sixty fourth aspect, an integrated system for converting hydrocarbons gases to solid carbon and hydrogen products comprises: a preheater configured to exchange heat between a feed stream of hydrocarbon gases and a heated particulate stream to produce a cold solids stream; a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media, wherein the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for inert media particles near a top of the bedof particulates, an outlet for the inert media near a middle of the bed of particulates, wherein the pyrolysis reactor is configured to convert a hydrocarbon gas into solid carbon and hydrogen in the bed or particulates; a separator system in fluid communication with the pyrolysis reactor through the product gas outlet, where the separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor; and a heat exchanger configured to exchange heat between the cold solids stream and the product gas.

[0139] A sixty fifth aspect can include the integrated system of the sixty fourth aspect, further comprising a cold solids conveyor, wherein the cold solids conveyor is configured to convey the cold solids from the preheater to the heat exchanger, and wherein the cold solids conveyor comprises a pneumatic conveyor.

[0140] A sixty sixth aspect can include the integrated system of the sixty fifth aspect, wherein the hydrocarbon gas comprises: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0141] A sixty seventh aspect can include the integrated system of any one of the sixty fourth to sixty sixth aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, or any combination thereof.

[0142] A sixty eighth aspect can include the integrated system of any one of the sixty’ fourth to sixty seventh aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0143] A sixty ninth aspect can include the integrated system of any one of the sixty fourth to sixty eighth aspects, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

[0144] In a seventieth aspect, a process for converting hydrocarbons gases to solid carbon and hydrogen products comprises: heating a feed stream using heat exchange with a particulate stream to produce a heated feed stream and a cold solids stream, wherein the feed stream comprises hydrocarbon gas; passing the heated feed stream to a pyrolysis reactor, wherein the pyrolysis reactor comprise a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media; converting the hydrocarbon gas to a product stream comprising solid carbon and hydrogen within the pyrolysis reactor; exchanging heat between the cold solids stream and the product stream to form a heated solids stream; and passing the heated solids stream back to the pyrolysis reactor.

[0145] A seventy first aspect can include the integrated system of the seventieth aspect, further comprising a cold solids conveyor, wherein the cold solids conveyor is configured to convey thecold solids from the preheater to the heat exchanger, and wherein the cold solids conveyor comprises a pneumatic conveyor.

[0146] A seventy second aspect can include the integrated system of the seventy first aspect, wherein the hydrocarbon gas comprises: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

[0147] A seventy third aspect can include the integrated system of any one of the seventy first to seventy second aspects, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, or any combination thereof.

[0148] A seventy fourth aspect can include the integrated system of any one of the seventy first to seventy third aspects, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

[0149] A seventy fifth aspect can include the integrated system of any one of the seventy first to seventy fourth aspects, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

[0150] It is to be further understood that the present description is not limited to the particular methodology, compounds, materials, manufacturing techniques, uses, and applications, described herein, as these may vary. It is also to be understood that the terminology7used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present systems and methods. It must be noted that as used herein and in the appended claims (in this application, or any derived applications thereof), the singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to "an element" is a reference to one or more elements and includes equivalents thereof known to those skilled in the art. All conjunctions used are to be understood in the most inclusive sense possible. Thus, the word "or" should be understood as having the definition of a logical "or" rather than that of a logical "exclusive or" unless the context clearly necessitates otherwise. Structures described herein are to be understood also to refer to functional equivalents of such structures. Language that may be construed to express approximation should be so understood unless the context clearly dictates otherwise.

[0151] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary' skill in the art to which this description belongs. Preferred methods, techniques, devices, and materials are described, although any methods, techniques, devices, or materials similar or equivalent to those described herein may be used in the practice or testing of the present systems and methods. Structures described hereinare to be understood also to refer to functional equivalents of such structures. The present systems and methods will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.

[0152] From reading the present disclosure, other variations and modifications will be apparent to persons skilled in the art. Such variations and modifications may involve equivalent and other features which are already known in the art, and which may be used instead of or in addition to features already described herein.

[0153] Although Claims may be formulated in this Application or of any further Application derived therefrom, to particular combinations of features, it should be understood that the scope of the disclosure also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalization thereof, whether or not it relates to the same systems or methods as presently claimed in any Claim and whether or not it mitigates any or all of the same technical problems as do the present systems and methods.

[0154] Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The Applicants hereby give notice that new claims may be formulated to such features and / or combinations of such features during the prosecution of the present Application or of any further Application derived therefrom.

Claims

CLAIMSWhat is claimed is:

1. An integrated system for converting hydrocarbons gases to solid carbon and hydrogen products, the system comprising: a preheater configured to exchange heat between a feed stream of hydrocarbon gases and reaction product gases; a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media, wherein the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for heated inert media particles near a top of the bed of particulates, an outlet for the inert media near a bottom of the bed of particulates; a heating section in fluid communication with the pyrolysis reactor, wherein the heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet; a separator sy stem in fluid communication with the pyrolysis reactor through the product gas outlet, where the separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor; and a heat exchanger configured to remove heat from the reaction product gases exiting the pyrolysis reactor.

2. The integrated system of claim 1, further comprising: a gas absorber-separation system in fluid communication with the pyrolysis reactor, wherein the gas absorber-separation system is configured to separate hydrogen gas from the reaction product gases.

3. The integrated system of claim 1, wherein the separator system comprises one or more cyclone separators.

4. The integrated system of claim 1, wherein the height of the reactor vessel is at least 5 times the minimum diameter of the reactor vessel.

5. The integrated system of claim 1, wherein the hydrocarbon gases comprise: methane, ethane, natural gas. alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

6. The integrated system of claim 1, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

7. The integrated system of claim 1, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

8. The integrated system of claim 1 , wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

9. The integrated system of claim 1, wherein a first zone of the at least three zones comprises a lower zone, wherein the lower zone has a smaller diameter than any other zone of the at least three zones, and wherein the lower zone is at least 50 wt.% of the inert media in the bed of particulates.

10. The integrated system of claim 1. wherein a second zone of the at least three zones compnses a pyrolysis zone, wherein the pyrolysis zone has a larger diameter than a zone of the at least three zones having a smallest diameter, and wherein the pyrolysis zone has a smaller diameter than a zone of the at least three zones having a largest diameter, wherein the pyrolysis zone comprises at least 50 vol% catalyst or catalyst precursors in the bed of particulates.1 1. The integrated system of claim 1 , wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a larger diameter than any other zone of the at least three zones, and wherein the disengagement zone has less than 20 vol.% solids.

12. The integrated system of claim 1, wherein the catalyst or catalyst precursors are in a condensed phase.

13. A process for converting hydrocarbons gases to solid carbon and hydrogen products, the process comprising: heating a feed stream to produce a heated feed stream by exchanging heat between the feed stream and a reaction product gas stream, w herein the feed stream comprises hydrocarbon gas; passing the heated feed stream to a pyrolysis reactor, wherein the pyrolysis reactor comprises a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media;contacting the heated feed stream with the catalyst particles to form reaction products comprising solid carbon and hydrogen from the hydrocarbon gas; removing a portion of the inert media from the bed of particulates during the contacting; heating the inert media removed from the bed of particulates in a heating section to form heated inert media; passing the heated inert media back to the bed of particulates; separating the reaction products to form a solid carbon product and a gaseous product; and extracting heat from the reaction products downstream of the pyrolysis reactor.

14. The process of claim 13, further comprising: separating a hydrogen gas stream from the reaction products downstream of the pyrolysis reactor.

15. The process of claim 13, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

16. The process of claim 13, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

17. The process of claim 13, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

18. The process of claim 13, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or cataly st precursors.

19. The process of claim 13. wherein the pyrolysis reactor operates at a temperature between about 750 °C to about 1,000 °C.

20. The process of claim 13, wherein heated feed stream flows through the bed of particulates at a flow rate sufficient to form a fluidized bed within at least a portion of the reactor vessel.

21. The process of claim 13. further comprising: stratifying the bed of particulates in response to passing the heated feed gas through the bed of particulates, wherein the bed of particulates partially or wholly segregates under the influence of the heated feed gas flowing upwards through the reactor vessel.

22. An integrated system for converting hydrocarbons gases to solid carbon and hy drogen products, the system comprising: a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media, wherein the pyrolysis reactor comprises a feed gas inlet at a lower portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for heated inert media particles near a top of the bed of particulates, an outlet for the inert media near a bottom of the bed of particulates; a heating section in fluid communication with the pyrolysis reactor, wherein the heating section is configured to heat the inert media in a hot gas stream and lift the heated inert media to the top of the heating section to return the heated inert media through the top inert media inlet; and a carbon formation reactor in fluid communication with an outlet of the heating section, wherein the carbon formation reactor is configured to receive the hot gas stream from the heating section and convert at least a portion of carbon oxides in the hot gas stream to solid carbon and water.

23. The integrated system of claim 22, further comprising: a feed gas inlet into the carbon formation reactor, wherein the feed gas inlet is configured to receive a hydrogen or hydrocarbon stream for the conversion of at least the portion of carbon oxides in the hot gas stream to the solid carbon and the water.

24. The integrated system of claim 22, wherein the carbon formation reactor comprises a carbon formation catalyst, and wherein the carbon formation catalyst comprises an element of Group VI, Group VII, Group VIII, Group IX, or Group X of the Periodic Table of Elements, an actinide, a lanthanide, oxides thereof, alloys thereof, or combinations thereof.

25. The integrated system of claim 22. wherein the hydrocarbon gases comprise: methane, ethane, natural gas. alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

26. The integrated system of claim 22, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

27. The integrated system of claim 22. wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

28. The integrated system of claim 22, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

29. A process for converting hydrocarbons gases to solid carbon and hydrogen products, the system comprising: passing a feed stream through a bed of particulates in a reactor vessel, wherein the feed stream comprises hydrocarbon gas, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media; forming a product stream within the reactor vessel based on reacting the feed stream with the catalyst particles, wherein the product stream comprises solid carbon and hydrogen; passing a portion of the inert media from the reactor vessel to a heating section; combusting a combustion gas in the heating section to produce combustion products, wherein the combustion products comprise carbon oxides; contacting the combustion products with the inert media to produce heated inert media; passing the combustion products to a carbon formation reactor; and converting at least a portion of the carbon oxides in the combustion products to solid carbon within the carbon formation reactor.

30. The process of claim 29. further comprising: passing a hydrogen or hydrocarbon stream into the carbon formation reactor during the converting to form the solid carbon and water.

31. The process of claim 29, wherein the carbon formation reactor comprises a carbon formation catalyst, and wherein the carbon formation catalyst comprises an element of Group VI, Group VII, Group VIII, Group IX, or Group X of the Periodic Table of Elements, an actinide, a lanthanide, oxides thereof, alloys thereof, or combinations thereof.

32. The process of claim 29, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

33. The process of claim 29, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

34. The process of claim 29, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

35. The process of claim 29, wherein the inert mediahas a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

36. The process of claim 29, wherein the carbon formation reactor operates at a temperature between about 400 °C and about 1000 °C.

37. The process of claim 29. wherein the carbon formation reactor operates as a fluidized bed reactor.

38. A chemical reactor for converting hydrocarbons gases to solid carbon and hydrogen products, the reactor comprising: a reactor vessel comprising a first inlet for hydrocarbon gases, a second inlet for catalyst or catalyst precursors, a third inlet for inert media, one or more first outlets for product gases, and product solids with catalyst, or both, and one or more second outlets for inert media; wherein a diameter of the reactor vessel varies along a height of the reactor vessel, wherein the diameter of the reactor vessel defines at least three distinct zones each having different diameters, where the at least three distinct zones are configured to have different gas-solid interactions based on the different diameters, and wherein the diameter is configured to control a gas velocity within the reactor vessel to control gas-solid interactions within the reactor to allow varying degrees of fluidization of the solids within the reactor vessel; and a bed of particulates disposed within the reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media in a stratified arrangement, wherein the bed of particulates is configured to become partially or wholly segregated under the influence of gases flowing upw ards through the reactor vessel.

39. The chemical reactor of claim 38, further comprising: a heating section in fluid communication with the reactor vessel, wherein the heating section comprises a heating leg configured to receive inert media from the reactor vessel, receive a combustion gas and an oxidant gas, combust the combustion gas with the oxidant gas to heat the inert media and produce heated inert media, and return the heated inert media to the reactor vessel.

40. The chemical reactor of claim 38, wherein the heating section if configured to receive inert media from a lower zone of the reactor vessel and return the heated inert media to an upper zone of the reactor vessel.

41. The chemical reactor of claim 38, wherein the height of the reactor vessel is at least 5 times the minimum diameter of the reactor vessel.

42. The chemical reactor of claim 38, wherein the hydrocarbon gases comprise: methane, ethane, natural gas. alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

43. The chemical reactor of claim 38, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

44. The chemical reactor of claim 38, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

45. The chemical reactor of claim 38, wherein the inert media has a larger particle size than a particle size of the solid carbon containing the catalyst or catalyst precursors.

46. The chemical reactor of claim 38, wherein a first zone of the at least three zones compnses a lower zone, wherein the lower zone has a smaller diameter than any other zone of the at least three zones, and wherein the lower zone is at least 50 wt.% of the inert media in the bed of particulates.

47. The chemical reactor of claim 38. wherein a second zone of the at least three zones comprises a pyrolysis zone, wherein the pyrolysis zone has a larger diameter than a zone of the at least three zones having a smallest diameter, and wherein the pyrolysis zone has a smaller diameter than a zone of the at least three zones having a largest diameter, wherein the pyrolysis zone comprises at least 50 vol% catalyst or catalyst precursors in the bed of particulates.

48. The chemical reactor of claim 38, wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a larger diameter than any other zone of the at least three zones, and wherein the disengagement zone has less than 20 vol.% solids.

49. The chemical reactor of claim 38, wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a smaller diameter than a zone directly below the third zone.

50. The chemical reactor of claim 38, wherein the catalyst or catalyst precursors are in a condensed phase.

51. A process for converting hydrocarbons gases to solid carbon and hydrogen products, the process comprising: passing a feed gas comprising hydrocarbon gases into a reactor vessel, wherein the reactor vessel comprises a first inlet for hydrocarbon gases, a second inlet for catalyst or catalyst precursors, a third inlet for inert media, and a first outlet for product gases and product solids with catalyst, and a second outlet for inert media, wherein a diameter of the reactor vessel varies along a height of the reactor vessel, and wherein the diameter of the reactor vessel defines at least three distinct zones each having different diameters, passing the feed gas through a bed of particulates disposed within the reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media in a stratified arrangement, forming solid carbon and hydrogen as the feed gas passes through the bed of particulates; and stratifying the bed of particulates in response to passing the feed gas through the bed of particulates, wherein the bed of particulates partially or wholly segregates under the influence of the feed gas flowing upwards through the reactor vessel.

52. The process of claim 51 , further comprising: passing a portion of the inert media from the reactor vessel to a heating section; contacting a heating gas with the inert media to produce heated inert media; and passing the heated inert media back to the reactor vessel.

53. The process of claim 51, further comprising: combusting a combustion gas in the heating section to produce combustion products, wherein the heating gas comprises the combustion products.

54. The process of claim 51 , wherein the heating section receives inert media from a lower zone of the reactor vessel and returns the heated inert media to an upper zone of the reactor vessel.

55. The process of claim 51. wherein the height of the reactor vessel is at least 5 times the minimum diameter of the reactor vessel.

56. The process of claim 51, wherein the hydrocarbon gases comprise: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

57. The process of claim 51, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, oxides thereof, carbides thereof, or any combination thereof.

58. The process of claim 51, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

59. The process of claim 51 , wherein the inert media has a larger particle size than a particle size of the solid carbon containing the catalyst or catalyst precursors, and wherein the catalyst or catalyst precursors segregate from the inert media based on differences in size and density.

60. The process of claim 51, wherein a first zone of the at least three zones comprises a lower zone, wherein the lower zone has a smaller diameter than any other zone of the at least three zones, and wherein the lower zone is at least 50 wt.% of the inert media in the bed of particulates.

61. The process of claim 51, wherein a second zone of the at least three zones comprises a pyrolysis zone, wherein the pyrolysis zone has a larger diameter than a zone of the at least three zones having a smallest diameter, and wherein the pyrolysis zone has a smaller diameter than a zone of the at least three zones having a largest diameter, wherein the pyrolysis zone comprises at least 50 vol% catalyst or catalyst precursors in the bed of particulates.

62. The process of claim 51. wherein a third zone of the at least three zones comprises a disengagement zone, wherein the disengagement zone has a larger diameter than any other zone of the at least three zones, and wherein the disengagement zone has less than 20 vol.% solids.

63. The chemical reactor of claim 51, wherein the catalyst or catalyst precursors are in a condensed phase.

64. An integrated system for converting hydrocarbons gases to solid carbon and hydrogen products, the system comprising: a preheater configured to exchange heat between a feed stream of hydrocarbon gases and a heated particulate stream to produce a cold solids stream; a pyrolysis reactor comprising a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media, wherein the pyrolysis reactor comprises a feed gas inlet at a low er portion of the bed of particulates, a product gas and solid outlet above the bed of particulates, an inlet for inert media particles near a top of the bed of particulates, an outlet for the inert medianear a middle of the bed ofparticulates, wherein the pyrolysis reactor is configured to convert a hydrocarbon gas into solid carbon and hydrogen in the bed or particulates; a separator system in fluid communication with the pyrolysis reactor through the product gas outlet, where the separator system is configured to separate any particulates in a product gas produced in the pyrolysis reactor; and a heat exchanger configured to exchange heat between the cold solids stream and the product gas.

65. The integrated system of claim 64, further comprising a cold solids conveyor, wherein the cold solids conveyor is configured to convey the cold solids from the preheater to the heat exchanger, and wherein the cold solids conveyor comprises a pneumatic conveyor.

66. The integrated system of claim 64, wherein the hydrocarbon gas comprises: methane, ethane, natural gas, alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

67. The integrated system of claim 64, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, or any combination thereof.

68. The integrated system of claim 64, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

69. The integrated system of claim 64, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

70. A process for converting hydrocarbons gases to solid carbon and hydrogen products, the system comprising: heating a feed stream using heat exchange with a particulate stream to produce a heated feed stream and a cold solids stream, wherein the feed stream comprises hydrocarbon gas; passing the heated feed stream to a pyrolysis reactor, wherein the pyrolysis reactor comprise a bed of particulates disposed in a reactor vessel, wherein the bed of particulates comprises catalyst particles, solid carbon, and inert media; converting the hydrocarbon gas to a product stream comprising solid carbon and hydrogen within the pyrolysis reactor; exchanging heat between the cold solids stream and the product stream to form a heated solids stream; and passing the heated solids stream back to the pyrolysis reactor.

71. The integrated system of claim 70, further comprising a cold solids conveyor, wherein the cold solids conveyor is configured to convey the cold solids from the preheater to the heat exchanger, and wherein the cold solids conveyor comprises a pneumatic conveyor.

72. The integrated system of claim 71, wherein the hydrocarbon gas comprises: methane, ethane, natural gas. alkenes, alcohols, liquid hydrocarbons, solid hydrocarbons, or any combination thereof.

73. The integrated system of claim 70, wherein the catalyst or catalyst precursors comprise iron, nickel, cobalt, or any combination thereof.

74. The integrated system of claim 70, wherein the inert media comprises sand, silica, alumina, zirconia, silicon carbide, carbon, or any combination thereof.

75. The integrated system of claim 70, wherein the inert media has a larger particle size than a particle size of the catalyst or catalyst precursors or the solid carbon containing the catalyst or catalyst precursors.

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