WO2024054914A1

WO2024054914A1 - Reactor and process for producing carbonaceous materials

Info

Publication number: WO2024054914A1
Application number: PCT/US2023/073644
Authority: WO
Inventors: Juzer Jangbarwala; Aram SARKISSIAN
Original assignee: Pact Fuel, Llc
Priority date: 2022-09-07
Filing date: 2023-09-07
Publication date: 2024-03-14

Abstract

In embodiments of this disclosure, a fluidized bed reactor for the decomposition of a gaseous hydrocarbon into nanofibers and other carbonaceous materials and hydrogen includes a gas impermeable structure comprising a continuous sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas through the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, the reaction vessel and gas impermeable structure having a common longitudinal axis, one or more gas distributors positioned to cause the hydrocarbon-containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel, and a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials.

Description

REACTOR AND PROCESS FOR PRODUCING CARBONACEOUS MATERIALS

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of and priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Serial Nos. 63/404,442, filed on September 7, 2022, and 63/419,258, filed October 25, 2022, both entitled "Reactor and Process for Producing Carbonaceous Materials," the entire disclosures of which are hereby incorporated herein by reference.

FIELD

The disclosure relates generally to a reactor as well as a process for producing carbonaceous materials and particularly to a reactor and process for producing carbon nanomaterial, specifically carbon nanofiber materials.

BACKGROUND

The thermal decomposition of methane to carbon and hydrogen gas, illustrated by reaction scheme (1) below, is a moderately endothermic process, but its energy requirement per mole of carbon produced (75.6 kJ/mol) is considerably less than that required by steam reforming processes (about 190 kJ/mol). Additionally, unlike steam reforming, the hydrogen produced by thermal decomposition of methane can be produced in an oxygen-free environment and does not involve a water-gas shift reaction, and the reaction can therefore produce both high-purity carbon and a hydrogen gas stream that is free of carbon monoxide.

CH₄ + 75.6

Thermal decomposition of natural gas has long been used to produce carbon black, with the resulting hydrogen gas being used as a supplementary fuel for the process. These processes are usually practiced in a semi-continuous fashion using two tandem reactors at high operational temperatures (typically about 1,400 °C), but those skilled in the art have attempted to reduce these operating temperatures via catalysis. Data on the catalytic decomposition of methane using aluminum-, cobalt-, chromium-, iron-, nickel-, platinum-, palladium-, and rhodium -based catalysts have been reported in the literature; see, e.g., Marina A. Ermakova et al., “Decomposition of methane over iron catalysts at the range of moderate temperatures: the influence of structure of the catalytic systems and the reaction conditions on the yield of carbon and morphology of carbon filaments,” 201(2) Journal of Catalysis 183 (luly 2001), the entirety of which is incorporated herein by reference. Directly catalyzed decomposition of methane offers two major advantages over thermal decomposition: (i) the operational temperature can be dramatically lowered, from about 1,400 °C to at least as low as about 550 °C, thereby significantly reducing the energy input requirements of the process, and (ii) various engineered carbon nanostructures of high value can also be generated by the judicial use of catalysts, thereby increasing the commercial value of the process. Because natural gas is widely available in large quantities, catalytic decomposition of methane to produce hydrogen gas and high- value carbon nanostructures on an industrial scale is technically feasible. However, for this decomposition process to be of practical, (z.e., commercial and financial) significance, highly effective catalysts, which heretofore have been unavailable, are required. Such catalysts should exhibit high activity for a prolonged period of time and continue to function in the presence of high concentrations of accumulated carbon.

Additionally, catalytic decomposition of methane can be a capricious process due to exacting requirements for metal particle size and the tendency of the reaction conditions to have a detrimental effect on catalyst morphology. Previous work has shown that the highest yields of solid carbon are obtained where the average particle size of the catalyst is about 30 to 40 nm, but also that nickel catalyst particles may undesirably aggregate as soon as the catalyst comes into contact with methane; see, e.g., M. A. Ermakova et al., “XRD studies of evolution of catalytic nickel nanoparticles during synthesis of filamentous carbon from methane,” 62(2) Catalysis Letters 93 (Oct. 1999), the entirety of which is incorporated herein by reference. This particle sintering behavior results in a reduction of catalytic activity. Thus, while the concept of generating carbon and hydrogen by catalyzed decomposition of methane has attracted intense interest and demonstrated technical feasibility, consistent achievement of a desired high-quality carbonaceous product has been difficult to achieve; many previous approaches in the art have failed to provide any degree of control over the type of carbon nanomaterials produced, and as a result the carbonaceous products of these approaches must be purified by chemical and physical processes that are typically difficult, expensive, and/or time-consuming, making them impractical for commercial applications.

Further, most catalytic cracking of methane and other solid carbon production reactors are the fixed bed type and have many disadvantages: a) endothermic reactions lower the surface temperature of catalysts, resulting in a slow to rapid formation of carbon solids on the active face of the catalysts, thereby inactivating the catalyst. This finally translates in very low yields and renders the reactor configuration inappropriate for the production of solid carbon structures. b) stationary catalyst particles get covered by the solid carbon nanomaterials, decreasing the driving force for the carbon molecule to chemisorb on the catalyst surface.

SUMMARY

These and other needs are addressed by the various aspects, embodiments, and configurations of the present disclosure.

In an embodiment of the disclosure, a rotating media fluidized bed reactor can include: a. an inlet for a hydrocarbon-containing gas; b. a gas impermeable structure comprising a continuous sidewall and hollow interior volume to receive the hydrocarbon-containing gas; c. plural gas distributors positioned around a periphery of the gas impermeable structure and in fluid communication with the hollow interior to receive at least most of the hydrocarbon-containing gas from the hollow interior volume and discharge the hydrocarbon-containing gas in a reaction zone located exteriorly to the gas impermeable structure to create a vortex fluid flow, the reaction zone comprises suspended catalyst particles to cause decomposition of hydrocarbons in the hydrocarbon-containing gas to form a carbonaceous material; and d. an exit gas conduit to receive a reacted gas, the exit gas conduit having an inlet positioned substantially at an axis of the vortex fluid flow.

In an embodiment of the disclosure, a method can include the steps of: a. introducing a hydrocarbon-containing gas into an inlet of a rotating media fluidized bed reactor, the fluidized bed reactor comprising: b. a gas impermeable structure comprising a continuous sidewall and hollow interior volume to receive the hydrocarbon-containing gas; and c. a gas distributor positioned at a periphery of the gas impermeable structure and in fluid communication with the hollow interior to receive at least most of the hydrocarbon-containing gas from the hollow interior volume and discharge the hydrocarbon-containing gas into a reaction zone located exteriorly to the gas impermeable structure to create a vortex fluid flow, the reaction zone comprising suspended catalyst particles to cause decomposition of hydrocarbons in the hydrocarbon-containing gas to form a carbonaceous material; d. removing a reacted gas from an exit gas conduit of the reactor; and e. removing a composite material comprising carbonaceous product and catalyst particles from the reactor.

In an embodiment of the disclosure, a rotating media fluidized bed reactor can include: a. an inlet for a hydrocarbon-containing gas; b. a gas impermeable structure comprising a continuous sidewall and hollow interior volume to receive the hydrocarbon-containing gas; c. a gas distributor positioned near a periphery of the gas impermeable structure and in fluid communication with the hollow interior to receive at least most of the hydrocarbon-containing gas from the hollow interior volume and discharge the hydrocarbon-containing gas in a reaction zone located exteriorly to the gas impermeable structure to create a vortex fluid flow, the reaction zone comprises suspended catalyst particles to cause decomposition of hydrocarbons in the hydrocarbon-containing gas to form a carbonaceous material; and d. an exit gas conduit to receive a reacted gas, the exit gas conduit having an inlet positioned substantially at an axis of the vortex fluid flow.

To assist the vortex flow pattern and provide better catalyst particle suspension, each gas distributor can include an upwardly angled ramp surface to direct the discharged hydrocarbon-containing gas upwardly along a path of flow transverse to a central axis of the reactor and/or tangential to the continuous sidewall of the gas impermeable structure. Each of the plural gas distributors comprises an inlet and outlet, each of which can be oriented in a substantially vertical plane to avoid orifice blockage, and a passage interconnecting the inlet and outlet, and the passage can have an arcuate central axis.

The reactor can include a gas curtain generator positioned at the inlet to the exit gas conduit to discharge a curtain gas in a direction of flow transverse to a direction of flow of the reacted gas to reduce a velocity of the reacted gas and substantially inhibit entry of entrained catalyst particles into the exit gas conduit.

In an embodiment of the disclosure, a reactor system can include: a. a reaction vessel comprising an inlet for a hydrocarbon-containing gas and an outlet for a reacted gas stream; b. a gas impermeable structure comprising a continuous sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas through the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, the reaction vessel and gas impermeable structure having a common longitudinal axis; c. one or more gas distributors positioned to cause the hydrocarbon- containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel; and d. a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials.

In an embodiment of the disclosure, a method can include the steps of: a. introducing a hydrocarbon-containing gas into an inlet of a reaction vessel, the reaction vessel comprising: i. a gas impermeable structure comprising a sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas through the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end; ii. one or more gas distributors positioned to cause the hydrocarbon- containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel; and iii. a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials.; b. removing a reacted gas from an exit gas conduit of the reactor; and c. removing a composite material comprising carbonaceous product and catalyst particles from an outlet of the reactor.

In an embodiment of the disclosure, a reactor system can include: a. a reaction vessel comprising an inlet for a hydrocarbon-containing gas and an outlet for a reacted gas stream; b. a gas impermeable structure comprising a continuous sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas through the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, the reaction vessel and gas impermeable structure having a common longitudinal axis; c. one or more rotatable blades having an axis of rotation along the common longitudinal axis to cause the hydrocarbon-containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel; d. a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials; and e. a quiet zone at an upper end of the reaction vessel between the first end of the gas impermeable structure and an opposing upper surface of the reaction vessel, wherein a velocity of the hydrocarbon-containing gas in the quiet zone is less than a gas velocity required to entrain at least about 5% of the catalyst particulates in the bed of catalyst particulates.

The gas impermeable structure in any of the above embodiments can have a number of three-dimensional shapes. For example, the gas impermeable structure can comprise a polygonal prism, wherein the sidewall is a surface of the polygonal prism. The gas impermeable structure can comprise an arcuate sidewall, such as the sidewall of a cone or frustoconical prism.

While any reaction can occur in the reactor system of the above embodiments, the reactor and method are typically used to catalytically decompose hydrocarbon in the hydrocarbon-containing gas into carbon nanofibers and hydrogen gas.

The gas distributor in any of the above embodiments can be stationary and comprise multiple gas distributors positioned substantially uniformly around a periphery of the gas impermeable structure.

The gas distributors in any of the above embodiments can include one or more gas injectors of the hydrocarbon-containing gas and/or one or more rotatable surfaces.

The gas distributor in any of the above embodiments can be rotatable and rotate about a longitudinal axis of the reactor and/or gas impermeable structure.

The continuous sidewall in any of the above embodiments can be arcuate, and the gas impermeable structure can include an open cylinder centered about a longitudinal axis of a reactor cylindrical sidewall.

A quiet zone in any of the above embodiments can be located at an upper end of the reaction vessel between the first end of the gas impermeable structure and an opposing upper surface of the reaction vessel. A velocity of the hydrocarbon-containing gas in the quiet zone is typically less than a gas velocity required to entrain at least about 5% of the catalyst particulates in the bed of catalyst particulates.

The operating conditions of the reactor system in any of the above embodiments depend on the particular implementation. A pressure of the hydrocarbon-containing gas typically ranges from about -100 KPa to about 100,000 KPa; a first velocity of the hydrocarbon-containing gas in the hollow interior volume typically ranges from about 0.015 to about 20 fps, a second velocity of the hydrocarbon-containing gas in the quiet zone typically ranges from about 0.15 to about 20 fps, and a third velocity of the hydrocarbon-containing gas in the fluidized bed typically ranges from about 0.015 to about 20 fps; a temperature of the hydrocarbon-containing gas in the fluidized bed typically ranges from about 550 to about 850 °C; a P90 size of particulate catalyst particles typically ranges from about 0.1 to about 5 microns; the gas impermeable structure is commonly an open elliptic or circular cylinder with the first and second ends of the gas impermeable structure being spaced from a respective opposing surface of the reaction vessel; and a ratio of a height (H) of the gas impermeable structure: the diameter (D) or width (W) of the gas impermeable structure ranging from about 1 : 1 to about 6:1 .

The reactor system in any of the above embodiments can use a bimodal technique to remove carbonaceous products. In a first mode, the gas impermeable structure can be in a first position that is hermetically sealed to enable catalytic decomposition of hydrocarbons and, in a second mode, the gas impermeable structure can be in a different second position that is not hermetically sealed to enable removal of carbonaceous material from the reaction zone.

In any of the above embodiments, a vacuum pump can be positioned between a heat exchanger and pressure swing absorption system to create a partial vacuum to cause flow of the reacted gas stream. The heat exchanger transfers heat from reacted gas stream to the hydrocarbon-containing gas, and the vacuum pump is in fluid communication with the outlet of the reaction vessel.

The present disclosure can provide a number of advantages depending on the particular configuration. For example, vortex flow can provide a higher slip velocity, which provides better heat and mass transfer. The quiet zone to inhibit particulate entrainment in the reacted gas can prevent clogging of the particle separator. A vacuum pump can maintain operating pressure within the reactor to within safe operating requirements. The reactor system can inexpensively produce nanofibers as a bulk material. The lengths of the nanofibers can be controlled by controlling the gas velocity in the reaction zone; that is, higher fluidizing gas velocities generally yield shorter nanofiber product lengths due to increased gas turbulence while lower fluidizing gas velocities yield longer nanofiber product lengths The process can be either a continuous batch process or continuous process depending on the implementation.

These and other advantages will be apparent from the disclosure of the aspects, embodiments, and configurations contained herein

As used herein, " at least one", "one or more", and "and/or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", "A, B, and/or C", and "A, B, or C" means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. When each one of A, B, and C in the above expressions refers to an element, such as X, Y, and Z, or class of elements, such as Xi-Xn, Yi-Y_m, and Zi-Z₀, the phrase is intended to refer to a single element selected from X, Y, and Z, a combination of elements selected from the same class (e.g., Xi and X2) as well as a combination of elements selected from two or more classes (e.g., Yi and Z_o).

It is to be noted that the term "a" or "an" entity refers to one or more of that entity. As such, the terms "a" (or "an"), "one or more" and "at least one" can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.

The term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C., Section 112(f) and/or Section 112, Paragraph 6. Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials or acts and the equivalents thereof shall include all those described in the summary of the disclosure, brief description of the drawings, detailed description, abstract, and claims themselves.

Unless otherwise noted, all component or composition levels are in reference to the active portion of that component or composition and are exclusive of impurities, for example, residual solvents or by-products, which may be present in commercially available sources of such components or compositions.

All percentages and ratios are calculated by total composition weight, unless indicated otherwise. It should be understood that every maximum numerical limitation given throughout this disclosure is deemed to include each and every lower numerical limitation as an alternative, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this disclosure is deemed to include each and every higher numerical limitation as an alternative, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this disclosure is deemed to include each and every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. By way of example, the phrase from about 2 to about 4 includes the whole number and/or integer ranges from about 2 to about 3, from about 3 to about 4 and each possible range based on real (e.g., irrational and/or rational) numbers, such as from about 2.1 to about 4.9, from about 2.1 to about 3.4, and so on.

The preceding is a simplified summary of the disclosure to provide an understanding of some aspects of the disclosure. This summary is neither an extensive nor exhaustive overview of the disclosure and its various aspects, embodiments, and configurations. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure but to present selected concepts of the disclosure in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other aspects, embodiments, and configurations of the disclosure are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below. Also, while the disclosure is presented in terms of exemplary embodiments, it should be appreciated that individual aspects of the disclosure can be separately claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the disclosure. The drawings simply illustrate preferred and alternative examples of how the disclosure can be made and used and are not to be construed as limiting the disclosure to only the illustrated and described examples. Further features and advantages will become apparent from the following, more detailed, description of the various aspects, embodiments, and configurations of the disclosure, as illustrated by the drawings referenced below.

Fig. 1A is a block diagram of a reactor system according to an embodiment of this disclosure; Fig. IB is a block diagram of a reactor system according to an embodiment of this disclosure;

Fig. 2A is a schematic of the embodiment of Fig. 1;

Fig. 2B is a front view of a reactor system according to the embodiment of Fig. 1;

Fig. 3 is a rear perspective view of the reactor system of Fig. 2B (with the reactor housing sidewall omitted);

Fig. 4 is a top perspective view of the reactor system of Fig. 2B (with the reactor housing sidewall omitted);

Fig. 5 is a front cross-sectional view of the reactor system of Fig. 2B;

Fig. 6A is a disassembled view of a portion of the reactor system of Fig. 2B;

Fig. 6B is an assembled view of the portion of the reactor system shown in Fig. 6A;

Fig. 7 is a cross-sectional view of a portion of the reactor system of Fig. 2B;

Fig. 8 is a side view of a gas distribution apparatus of the reactor system of Fig. 2B;

Fig. 9 is a disassembled view of the portion of the reactor system shown in Fig. 7;

Fig. 10 is a perspective disassembled view of the portion of the reactor system shown in Fig. 7;

Fig. 11 is a cross-sectional view of a portion of the reactor system of Fig. 2B;

Fig. 12 is a perspective cross-sectional view of a portion of the reactor system of Fig. 2B;

Fig. 13 is a plan view of the gas distribution apparatus of the reactor system of Fig. 2B;

Fig. 14 is an exploded view of a portion of the gas distribution apparatus of the reactor system of Fig. 2B;

Fig. 15 is an exploded view of a portion of the gas distribution apparatus of the reactor system of Fig. 2B;

Fig. 17 is a bottom view of the gas distribution apparatus and reactor cone of the reactor system of Fig. 2B;

Fig. 18 is a side view of a portion of the gas distribution apparatus and reactor cone of the reactor system of Fig. 2B;

Fig. 19 is a partial side cross-sectional view of the portion of the gas distribution apparatus and reactor cone of Fig. 18; Fig. 20 is a side cross-sectional view of the portion of the gas distribution apparatus and reactor cone of Fig. 18;

Fig. 21 is another side cross-sectional view of the portion of the gas distribution apparatus and reactor cone of Fig. 18;

Fig. 22 is a side view of a gas curtain generator of the reactor system of Fig. 2B;

Fig. 23 is a bottom view of the gas curtain generator of Fig. 22;

Fig. 24 is a top view of the gas curtain generator of Fig. 22;

Fig. 25 is a top cross-sectional view of the gas curtain generator of Fig. 22;

Fig. 26 is a bottom cross-sectional view of the gas curtain generator of Fig. 22;

Fig. 27 depicts a first spatial position of the reactor cone apparatus of the reactor system of Fig. 2B that enables product and catalyst removal;

Fig. 28 depicts a second spatial position of the reactor cone apparatus of the reactor system of Fig. 2B that enables catalytic production of product;

Fig. 29A is a block diagram of a reactor system according to an embodiment of this disclosure;

Fig. 29B is a block diagram of a reactor system according to an embodiment of this disclosure;

Fig. 30A is a cross-sectional view of a reactor along a longitudinal bisecting plane according to an embodiment of the disclosure;

Fig. 30B is a cross-sectional view of a reactor along a longitudinal bisecting plane according to an embodiment of the disclosure;

Fig. 31 A is a block diagram of a reactor system according to an embodiment of this disclosure;

Fig. 3 IB is a block diagram of a reactor system according to an embodiment of this disclosure;

Fig. 32 is a block diagram of a reactor system according to an embodiment of this disclosure; and

Fig. 33 is a cross sectional view of the reactor of Figs. 30A and 3 OB in a latitudinal bisecting plane according to an embodiment of this disclosure.

DETAILED DESCRIPTION

In embodiments of this disclosure, a stationary chamber rotating media fluidized bed reactor for the decomposition of a gaseous hydrocarbon into nanofibers and other carbonaceous materials and hydrogen is described. The reactor can have a stationary or rotating gas distributor that comprises angled slots and/or precision orifices to create a slip velocity vortex of reactant gas flow around a gas impermeable cone. A “slip velocity vortex refers to a vortex flow pattern comprising the hydrocarbon gas and particulate catalyst providing a slip velocity, or a difference between the velocity of the particulate catalyst and the velocity of the gas phase. In fluid dynamics, a vortex is a region in a fluid in which the flow revolves around an axis line, which may be straight, curved or curvilinear. While the embodiments discussed below are with reference to a stationary gas distribution assembly, it is to be appreciated that the gas distribution assembly may be configured to rotate about the longitudinal axis of reacted gas exit tubing positioned centrally within the reactor.

In embodiments of this disclosure, a fluidized bed reactor for the decomposition of a gaseous hydrocarbon into nanofibers and other carbonaceous materials and hydrogen gas incorporates a stationary or moving gas impermeable and open-ended baffle to position the fluidized bed in an annular space between the baffle and reactor wall while leaving an interior volume of the baffle substantially free of catalyst particulates. Gas flow through the open baffle ends, downwardly through the baffle interior volume, and upwardly through annular space to fluidize the bed is provided by rotation of one or more blades having an axis of rotation substantially aligned with a common longitudinal axis of the baffle and reactor.

It is also to be understood in the above embodiments that an innovation can be achieved by either pumping the reactant gases with a blower preceding the reactor or a vacuum pump placed on the exit of the reactor, both techniques achieving the same reactant gas transport requirement.

With reference to Fig. 1 A, an embodiment of a hydrocarbon gas decomposition reactor system 100 according to the present disclosure is depicted. The reactor system 100 comprises a reactor 101 discussed in greater detail below in fluid communication with particle separator 122 and heat exchanger (HX) 106 via conduit 105. Fresh hydrocarbon feed or hydrocarbon gas 110 is preheated in HX 106 to temperatures amenable for separation. The hydrocarbon gas decomposition reaction selectively produces first intermediate and second intermediate carbonaceous products 125 and 114 from particulate catalyst 123 and hydrocarbon gas 110.

The fresh hydrocarbon gas 110 is first pre heated by the waste heat from the product or reacted gas 190 in HX 106. The pre heated gas 110A then flows to a mixing (equalization) tank 104 and flows as a mix of new and recovered methane 113 into the preheater 124 where it is heated together with hydrogen 111 A partially rerouted from the recovered hydrogen stream 111 from the pressure swing adsorption (PSA). A PSA is a gas separation device well known in the industry and separates a gas species from a mixture of gases under pressure according to the species' molecular characteristics and affinity for an adsorbent material. By controlling the pressure and temperature, specific dew points can be dialed in, retarding the movement of one gas from others. Specifically, in the present disclosure, the product gas 111 from the reactor 101 will be a mixture of hydrogen and unreacted methane. In the recovery of methane from a PSA, a “sweep” gas is commonly used to remove the methane from the PSA pressure vessel. Hydrogen (H2) is generally used as the sweep gas and becomes part of the “recovered methane” gas. The PSA will route the methane to the equalization tank 104, where the recovered methane will be mixed with fresh methane. The mixed gases are pre heated by preheater 124 to reaction temperature and fed to the reactor as a preheated mixed gas stream 126. The hydrocarbon gas can be any gaseous hydrocarbon, with shorter chain hydrocarbon gases, such as a gas from the alkane group (e g., methane, ethane, propane, butane, pentane, and hexane), being typical and methane more typical. The hydrocarbon gas can also be any gas from the alkene group (carbon to carbon double bond), alkyne group (carbon to carbon triple bond) or an aromatic group. In one embodiment, the hydrocarbon gas comprises at least about 50 mole percent more typically at least about 75 mole percent and even more typically at least about 90 mole percent methane, with the balance being nitrogen, hydrogen or carbon dioxide gases. To avoid oxidation of the carbonaceous material forming on the particulate catalyst 123, the gas within the reactor system 100, including the hydrocarbon gas 110 is at least substantially free of molecular oxygen and other oxidants and typically contains no more than about 0.01 mole % of molecular oxygen and other oxidants.

The particulate catalyst 123 can be any metallic or intermetallic catalyst, such as AL, NI, CU, Co, Cr, Fe, Ni, Pt, Pd, and Rh-based catalysts and alloys of these metals. In one embodiment, the catalyst is an oxide alloy of a basic metal, transition metal, and alkaline earth metal, such as the catalyst disclosed in US Application 63/225,733, filed concurrently herewith entitled “Catalyst for the Generation of Graphitic Nonofibers and CO-Free Hydrogen”. The particulate catalyst 123 typically has a P90 size ranging from about 0.10 to about 5.0 microns.

The particle separator 122 can be any device that can separate gas from entrained particulates. In one implementation, the particle separator 122 is a cyclone separator that uses the principle of inertia to remove entrained particulate matter from an input gas stream. In a cyclone separator, the input gas is fed into a chamber that creates a spiral vortex. The lighter components of this gas have less inertia, so it is easier for them to be influenced by the vortex and travel up it. Contrarily, larger components of particulate matter have more inertia and are not as easily influenced by the vortex. In one implementation, the particle separator 122 is a centrifuge. Like the cyclone, the centrifuge spins objects around a center axis. This spinning pushes harder on dense material than on less dense material which separates objects by their densities.

In some implementations, the particle separator is a housing with cartridge type filter elements 191 that pass the reacted gas as the filtrate but retains entrained particles as the retentate with an automatic backpulse facilitated by preheated hydrogen gas 109A being used to cause the retentate to be removed from the filter media of the cartridges. The filter media can be backpulsed periodically during production of the carbonaceous material with valve 108B open and closing valve 108 A, temporarily suspending the fluid connection between the reactor 101 and the heat exchanger 106. The first intermediate carbonaceous product 125 from the back pulse (filtered solids) are directed back to the reactor chamber.

The mixed hydrocarbon gas 113 and hydrogen 111 A are pre heated by the preheater 124 and fed to the reactor 101 where it interacts with the particulate catalyst 123 to form first or second intermediate carbonaceous products 125 and 114. The hydrocarbon gas is typically heated to a temperature ranging from about 550 to about 850°C and input at a pressure ranging from about -100 KPa (when a vacuum pump is used to transport the reactant gas) to about 100 KPa (when a blower is used to transport the reactant gas) and gas velocity ranging from about 0.015 to about 20 fps. The mixed hydrocarbon gas 113 is diffused or distributed substantially in the reactor and suspends or fluidizes the particulate catalyst by forming a vortex flow pattern. Carbonaceous materials, typically carbon nanomaterial and more typically carbon nanofiber materials, grow on the suspended particulate catalyst 123 and, when the materials reach a threshold size, the materials, under the force of the fluidizing gas, break off, are suspended by the fluidizing gas, and, when the fluidizing gas is discontinued, fall to the bottom of the reactor as the second intermediate carbonaceous product. In one implementation, the process is operated under conditions substantially minimizing break off of the material and causing the particulate catalyst 123 and attached carbonaceous material to be removed by the fluidizing gas from the reactor 101 and into the particle separator 122 where they are separated from the gas as the first intermediate carbonaceous product 125. A back pulse on the cartridge type filter elements 1913 using hydrogen gas 109A returns the first intermediate product 125 back to the reactor 101.

In another embodiment, the cartridge type filter elements 191 of the particle separator 122 (Fig. IB) are suspended inside the reactor and the back pulse simply drops the first intermediate carbonaceous product back into the reactor 101. In this embodiment, no external particle separator 122 is typically employed.

Referring again to Fig. 2A to substantially minimize the volume of particles leaving the reactor and into the particle separator 122, a quiet zone mechanism to inhibit the particulate catalyst 123 and intermediate carbonaceous product from exiting the reactor 101 is provided. Via the gas flow conduit 112, a curtain gas 158 (e.g., a reducing gas such as hydrogen gas or a noble gas) forms a gas curtain, or reverse gas flow, within the conduit 112 to cause a decreased gas velocity within the quiet zone 201. As discussed below, the decreased gas velocity is below the gas velocity required to entrain the particulate catalyst 123 and/or intermediate carbonaceous product, thereby causing the particles to remain in the reactor 101. As will be appreciated, the reverse velocity of the curtain gas 158 is less than the exit velocity of the gas in the gas flow conduit 112, more typically is no more than about 75%, and even more typically no more than about 50% of the exit velocity.

Referring now to Fig. 2A, a more detailed embodiment of a reactor system 200 is depicted.

An input gas compressor or blower 109 feeds preheated hydrocarbon gas 110 into the reactor via input gas flow conduit 120, typically at a gas velocity ranging from about 0.015 to about 20 fps. The gas stream 126 is pushed at a first velocity (typically ranging from about 0.015 to about 20 fps) through a gas distributor assembly 204, comprising a cone 212 and gas distributor system 216, as shown by gas flow arrows 220 (which are typically substantially tangential to the rounded surface of the cone 212) to create a vortex 208 from the inflowing gas swirling at a lower second velocity (typically ranging from about 0.015 to about 20 fps) around the cone 212. The reactor cone 212 provides a conical gas impermeable structure for the gas vortex 208 to spin around.

The tapered continuous sidewall of the cone 212 provides for different cross- sectional areas of flow relative to the area between the cone sidewall and interior surface of the reactor 101. The varying cross-sectional areas of flow increasing progressively from the base of the cone to the cone apex can provide for different velocity zones and different slip velocities. In many applications, a lower velocity zone is proximal the base of the cone (and typically ranges from about 10 to about 15% of the height H of the cone 12), and an upper velocity zone is near an apex of the cone (and typically above about 40% of the cone height H), with an intermediate velocity zone being located therebetween (which typically ranges from about 15% to about 40% of the cone height H). The slip velocity in the lower velocity zone is typically less than the slip velocity in the intermediate velocity zone, and the slip velocity in the upper velocity zone is typically greater than the slip velocity in the intermediate and lower velocity zones. While a continuously tapered sidewall of the cone 212 is shown in the figures, it is to be appreciated that the sidewall can be discontinuously tapered or stepped to provide similar velocity zones.

Particulate catalyst 123 is placed into the reactor 101 prior to startup or fed through feed chamber 3228 (see Fig. 32) by a venturi action created by the reactant gas flow and/or during operation, and the vortex 208 created by the gas distributor 216 keeps the particulate catalyst 125 particles (not shown in drawing) suspended in a reaction zone having a turbulent regime flow around the circumference of the cone 212. The hgas stream 126 reacts with the suspended particulate catalyst 123 particles in the vortex 208, and the particulate catalyst 123 particles start growing carbonaceous material, such as graphite nanofibers, which increases the weight of the catalyst particles. The curtain gas 158 is fed into the reactor 101, via a top-down curtain gas flow conduit 224 positioned within gas flow conduit 112, and a gas curtain generator 226, in an opposing direction of flow to the gas stream 126 to form a gas curtain 228 of a third gas flow velocity less than the first and second gas flow velocities. The downward flow of curtain gas 158 effectively forms a curtain of low gas velocity (typically ranging from about 1 :3 to about 1:6 ratio of curtaimfeed flow rate) to prevent the particulate catalyst particles 123 from rising above the turbulent flow or reaction zone formed by the vortex 208. A gaseous mixture 210 of the unreacted hydrocarbon gas and gaseous byproducts (e g., hydrogen gas) and curtain gas exits as a particle-free gas from the vortex 208 via recycle flow conduit 112.

Reactor discharge bin 232 is fluidly connected to the reactor 101. Intermittently, when a sufficient amount of carbonaceous material has been broken off from the turbulence on the particulate catalyst 140 within the gas vortex 208, an input shaft 236 assists the slide of the gas distributor assembly 204 by following discharge guide 240 and the combination of these functions will tilt the gas distributor assembly 204 dropping carbonaceous material into the bin 232, which is hermetically sealed to prevent oxygen from coming into contact with the carbonaceous material.

The carbonaceous material is discharged from the discharge bin 232 using a jacketed cooling auger 244 driven by motor 248. The second intermediate carbonaceous product 136 is discharged to product storage tank 252 via an airlock 256 and jacketed cooling auger 260 driven by motor 264.

Referring to Figs. 2B and 3-5, a particular implementation of the reactor system 200 is depicted. The cylindrical reactor 101, particle separator 122, and compressor or blower 109 are shown in fluid communication with each other via the recycle flow conduits 112 and 116, input gas flow conduit 120, and recycle flow conduit 128. Referring to Fig. 5, the recycle flow conduit 128 and the recycle flow conduit 112 each extends into the interior of the reactor as shown by first and second recycle conduit segments 500 and 504, respectively. A first inlet 508 of the first recycle conduit segment 500 extends into the reactor interior a shorter distance than a second inlet 512 of the second recycle conduit segment 504; that is, the first inlet 508 is positioned above the second inlet 512 to prevent particulate catalyst particles 140 from premature removal from reaction zone. The second inlet 512 is positioned in spatial proximity to an apex 516 of the cone 212 and, in some implementations, is positioned within the second inlet 512 and second recycle conduit segment. The cone 212, recycle flow conduit 112, and second inlet 512 are centered about a longitudinal axis 272 of the reactor 101.

The embodiment of Figs. 2B and 3-5 comprises a second reactor discharge bin 520 positioned beneath the particle separator 122 to receive the first intermediate carbonaceous product 125. The use of dual reactor discharge bins 232 and 520 enables lighter composite particles, comprising the particulate catalyst 140 and lighter amounts of carbonaceous material (e.g., shorter carbon nanofiber lengths), to be removed by using gas flow velocities (higher than the second gas flow velocity) to blow the composite particles into the first inlet 508 for collection as the first intermediate carbonaceous product 125 in the second reactor discharge bin 520 and heavier composite particles, comprising the particulate catalyst 140 and heavier amounts of carbonaceous material (e.g., longer carbon nanofiber lengths), to be removed by spatial movement of the gas distributor assembly 204.

Referring to Figs. 6A, 6B, 9-10, 12, and 27-28, the discharge of the second intermediate carbonaceous product 125 into the reactor discharge bin 232 will be described. As can be seen from the figures, the gas distributor assembly 204 is fastened via plural fasteners 606 to the base of the reactor 101 and interior 1004 of the gas distribution system 216 via a flange assembly comprising a flange 600 and interconnected conduit segment 604. The inlet of the conduit segment 604 is connected to an outlet of an elbow 608 and the inlet of the elbow 608 movably engages the outlet of the input gas flow conduit 120. To maintain a hermetic seal between the elbow 608 and the input gas flow conduit 120, the inlet of the elbow 608 comprises a gasket assembly 1000.

To discharge the second intermediate carbonaceous product 114 into the reactor discharge bin 232, the reactor assembly 100 operates in first and second modes.

In a first mode shown in Fig. 28, the gas distributor assembly 204 comprising the cone 212 and gas distributor 216 is in engaged by a hermetic seal with the reactor 101 and the gasket assembly 1000 on the inlet of the elbow 608 engages and forms a hermetic seal with an outlet of the input gas flow conduit 120. The gas distributor assembly 204 and conduit segment 604 are in a first spatial position relative to a length of the discharge guide 240. In this configuration, the reactor 101 is fluidized with the hydrocarbon gas 110 to cause graphite or carbon nanofibers to form on the particulate catalyst 123.

In a second mode shown in Fig. 27, the gas distributor assembly is disengaged from (and no longer forms a hermetic seal with) the reactor 101 and the gasket assembly 1000 on the inlet of the elbow 608 is disengaged (and no longer forms a hermetic seal with) the outlet of the input gas flow conduit 120. The gas distributor assembly 204 and conduit segment 604 are in a second spatial position (different from the first spatial position) relative to the length of the discharge guide 240. In this configuration, the reactor 101 is not fluidized with the hydrocarbon gas 110 and the composite particles in the reactor 101 can be discharged into the reactor discharge bin 232.

Any displacement mechanism can be used to selectively place the reactor assembly in either the first or second mode. For example, the input shaft 236 can engage a cam that is rotated to cause the input shaft to move up and down. In another example, the input shaft is pneumatically or hydraulically displaced.

While the discharge guide 240 is shown as a guide rail movably engaging a guide member 2700 (e.g., protruding pin or wheel), any guide or linkage mechanism can be used, such as a linear slide mechanism comprising ball bearings moving along a shaft.

With reference to Figs. 7-8, and 13-21, the gas distributor assembly 204 will be described. The gas distributor assembly 204 comprises plural gas injectors 1416 positioned at substantially uniformly spaced locations around a circumference of the interior 1004 of the gas distributor assembly 204. Holes 1300 positioned at substantially uniformly spaced locations around the inlet 704 align with holes in the flange 600 and are configured to receive fasteners 606.

The interior volume 700 of the cone 212 is at least substantially hollow and the cone sidewalls impermeable to gas flow to act as a manifold for hydrocarbon gas entering via the inlet 704 such that the hollow interior substantially equalizes the inflowing hydrocarbon gas pressure before the gas passes through plural inlet orifices 708, flows through respective internal passageways 1400 and outward through respective output orifices 1404 in a substantially vertical surface 1406 into the reactor interior volume. To provide smoother gas flow and reduced gas pressure loss, the passageways 1400 are typically curved (e g., arcuate or in some cases radiused) and not sharply angled. The outflowing gas is directed by ramp 1408 along a path of flow substantially parallel to the ramp slope (which typically ranges from about 1 to about 75 degrees and more typically from about 1 to about 45 degrees relative to a horizontal plane) and into the reactor interior. The rounded edge 1412 of each of the plural gas injectors 1416 provides a smooth gas exit into the reactor interior.

Typically, the inlet and output orifices 708 and 1404 and each intervening passageway 1400 for each gas injector 1416 and for all gas injectors 1416 are substantially the same diameter. The diameter is selected to provide an output gas velocity that is at least the terminal velocity for the particulate catalyst particles to maintain entrainment of the particles and inhibit particle collection in the substantially flat surface 1416 at the output orifice 1404 and gas injector clogging. Typically, the output gas velocity ranges from about 0.5 to about 20 fps.

The cone angle 9 2000 (Fig. 20) formed between the cone sidewall and a horizontal plane determines the speed of the gas flow in the reaction zone and the size of the carbonaceous material (e g., graphite nanofibers) produced. For example, to produce longer graphite nanofibers the angle 9 is decreased to produce a lower gas velocity in the reaction zone, and to produce shorter graphite nanofibers the angle 9 is increased to produce a higher gas velocity in the reaction zone. Stated differently, the angle 9 for longer graphite nanofibers is less than the angle 9 for shorter graphite nanofibers. Typically, the angle 9 2909 ranges from about 1 to about 45 degrees and a ratio of the cone height (H) versus the cone diameter (D) (Fig. 8) ranges from about 1 : 1 to about 6: 1.

Referring to Figs. 11 and 22-26, the gas curtain generator 1100 that emits the curtain gas curtain will be described. The gas curtain generator 1100 is in fluid communication with a curtain gas supply conduit 1104 that connects to and forms a hermetic seal with a fitting 1108 of the generator 1100. The curtain gas flows through an inlet 2500, through a passageway 2504 and into an annular space 2508 for emission through an annular ring 1112 to form the gas curtain. As shown in Fig. 22, the diameter of the generator 1100 steps down from a first larger diameter inlet 2200 that engages the conduit segment 504 to a second diameter outlet 2204 having a smaller diameter. The step down is done using an intermediate section 2208 that progressively reduces diameter form the first diameter to the second diameter.

In another embodiment of the reactor design shown in Figs. 29A-B and 30A-B, the turbulent flow 208 is generated by recirculation of the feed gas internally. Unlike the reactor designs discussed above in which the turbulence 208 is in a substantially helical flow path around a periphery of the cone 212 (e g., in a flow path transverse to a longitudinal axis of the reactor), the turbulent flow 208 is in a substantially vertical plane due to the open upper and lower ends of the baffle 301 (e.g., in a plane substantially parallel to the longitudinal axis of the reactor). While the baffle 301 and reactor 300 can be in any desired curvate and/or angular and/or curvilinear latitudinal or longitudinal cross- sectional shape, the shapes of the baffle 301 and reactor 300 should be the same. Common cross-sectional shapes include elliptic or circular cylinders. For example, as shown in Fig. 33 a baffle 301 cylindrical in latitudinal cross section is used in a reactor that is also cylindrical in latitudinal cross section. The distance “D” between the exterior wall of the baffle and the interior wall of the reactor is substantially constant around the baffle circumference. As shown by Fig. 33, the cylindrical baffle 301 and reactor vessel share a common longitudinal axis. While the reactor is a closed vessel, the baffle 301 has open upper and lower ends 308 and 312 to permit gas to flow exteriorly upwards (as shown by flow arrows 314) and interiorly downwards relative to the baffle (gas impermeable) sidewalls 316 and around the upper and lower baffle ends 308 and 312 as shown. Reactor 300 comprises a fan assembly comprising a motor 303 in operative communication with one or more fan blades 320 via a drive shaft 324 to circulate the gas within the reactor 300 in the manner described. The gas is continuously circulated within the reactor by rotation of the one or more fan blades 320 typically in the counterclockwise direction so as to fluidize a bed of particulate catalyst particles located in a reaction zone 328 located between the sidewall 316 and reactor 300 wall. Typically, the open lower end of the baffle and baffle interior volume 330 are substantially free of catalyst particles. All external arrangements remain the same. While the reactor 300 is described with specific reference to a fan assembly, other methods may be used to induce fluidizing gas flow including gas injectors as noted above positioned at the upper end 308 of the reactor or at a lower end of reactor in the reaction zone outside of the sidewalls 316.

The quiet zone 390 is not formed using a gas curtain as in the case of the quiet zone 201. Rather, it is formed by careful control of the gas velocity in the reactor 300 coupled with the turbulent flow 208 pattern (which forms eddies that can prevent particulates from being entrained by the gas exiting the reactor). As discussed above, the gas velocity is maintained below the gas velocity required to entrain the particulate catalyst 123 and/or intermediate carbonaceous product, thereby causing the particles to remain in the reactor 300. As will be appreciated, the gas flow is typically maintained at a velocity of no more than about 90% and more typically no more than about 80% of the velocity required to entrain the unreacted catalyst particulates. As carbon nanomaterial form on the catalyst particles, the particles become heavier and require a higher velocity for entertainment. The highest level of particulate entrainment typically occurs when fresh catalyst particulates are introduced into the reactor 300. The dimensions of the quiet zone typically depend on the vertical gas velocity, size and weight/density of the particulates, reactor diameter, and the like.

In another embodiment of the reactor design shown in Figs. 31A-B, a product discharge phase (e.g., carbon discharge phase) may be deployed to remove composite material comprising carbonaceous product and/or catalyst particles (e.g., first or second intermediate carbonaceous products 125 and 114) from the reactor. The product discharge phase may be accomplished by reversing the flow of the fan assembly (e g., reversing the direction of the fan blades 320), typically in the clockwise direction, and the reactor flow pattern. Additionally, inlets 103, 105, 326, or a combination thereof may be sealed off. In one embodiment, inlets 103 and 105 may be sealed off, and inlet 326 may remain open during the product discharge phase. In some implementations, inlets 103 and 105 may be open during the catalyst feed cycle and may remain closed at all other times, such as during the product discharge phase. In one embodiment with reference to FIG. 31 A, inlet 326 and valve 108A may be closed for the product discharge phase. In one embodiment with reference to FIG. 3 IB, valve 108A may be closed, and inlet 326 may remain open for the product discharge phase.

As such, upon production of the carbonaceous product, one or more of inlets (e g., inlets 103, 105, and 326) and/or one or valves (e.g., valve 108A) may be closed (e.g., sealed off), such as in a batch reactor design, and the flow of the fan assembly may be reversed. In the product discharge phase and in response to the reversal of the fan direction, the flow of a backflow gas may flow exteriorly downwards and interiorly (which is typically hydrogen gas) upwards through the center of the filter housing (as depicted in Figs. 31 A through 3 IB). As such, the carbonaceous product may flow downward. The carbonaceous product may then exit the reactor via an opened valve, door, etc. at the bottom of the reactor. In some implementations, with reference to Figs. 31 A and 3 IB, line 322 may be opened (e.g., may cycle open) for the product discharge phase, such as to allow the product to be removed from the reactor. The carbonaceous product may be collected in a reactor discharge bin (117, 118, or both), such as a reactor discharge bin 232 as described with reference to Fig. 2A. In some implementations, the reactor discharge bin may include or lead to a cooling circuit.

The reactor designs of Figs. 29A, 30A, and 31 A can have an external filter reactor configuration as described above while the reactor design of Figs. 29B, 30B, and 3 IB can have an internal filter reactor configuration also described above.

While the reactor designs of Figs. 29 A, 30A, and 31 A can use a baffle having an open upper and/or lower end that is spaced from an opposing interior wall of the reactor vessel as shown in the figures, it is be appreciated that the open ended configuration can be realized through other baffle configurations. For example, a gas permeable upper or lower portion of the baffle can also be positioned adjacent to the gas impermeable central portion of the baffle. The gas permeability can result from a perforated or vented surface that has one or more openings, apertures, orifices, ports, or other holes to pass the gas stream. In some configurations, the opening size is smaller than the average, mean, median or Pso or P25 size (depending on the reactor configuration) of the catalyst particulates before substantial nanomaterial formation to maintain the baffle interior substantially free of catalyst particulates. The gas permeable upper or lower portion can connect with the upper or lower reactor vessel wall or be spaced from the wall. The gas permeable upper or lower portion can be positioned in only a portion or all of the upper or lower end of the baffle.

Another embodiment of the reactor system 3200 is shown in Fig. 32. The reactor system 3200 comprises a reactor 3204 (which can be any of the reactor configurations discussed above) in fluid communication with particle separator 122 and a multi-stage heat exchanger (HX) 106 via conduit 3208. Fresh hydrocarbon feed or hydrocarbon gas 110 (which is typically predominantly methane and/or other short chained hydrocarbons) is preheated in HX 106 to temperatures amenable for separation. The hydrocarbon gas decomposition reaction selectively produces first intermediate and second intermediate carbonaceous products 125 and 114 from particulate catalyst 123 and hydrocarbon gas 110.

The hydrocarbon gas 110 is first pre heated by the waste heat from the product or reacted gas 190 (which is a mixture of unreacted methane and/or other short chained hydrocarbons and byproduct hydrogen gas) in HX 106 to form a preheated hydrocarbon gas 3208 and cooled reacted gas 3212. The cooled reacted gas 3212 optionally passes through vacuum pump 3216 to create a partial vacuum and provide a driving force to cause gas flow through the reactor system 3200. The vacuum pump 3216 is positioned on the cooled gas discharge side of the heat exchanger 106 to improve pump performance by operating on a lower temperature gas stream. The vacuum pump 3216 can be any type of vacuum pump, such as a positive displacement, momentum transfer, and entrapment vacuum pump. The cooled reacted gas 3212 then flows into a compressor 3220 to pressurize the gas, which is a mixture of predominantly unreacted methane and/or other short chained hydrocarbons and byproduct hydrogen gas, for separation by the PSA 107 into a recovered hydrogen gas-containing stream 111 and separated hydrocarbon- containing stream 115. The PSA 107 is in fluid communication by a coolant with a chiller 3224 to maintain the PSA 107 within a desired operating temperature range.

The separated hydrocarbon -containing stream 115 then flows into the equalization tank 104 where it is mixed with the preheated hydrocarbon gas 3208 to form a mixed gas stream 113. Optionally, a bleed stream of the recovered hydrogen stream 111 may be introduced into the equalization tank 104 to provide the desired gas mixture. Typically, the mixed gas stream comprises from about 70 to about 100 mole % methane and/or other short chained hydrocarbons and from about 30 to about 0 mole % hydrogen (H2).

The mixed gases are pre heated by preheater 124 to reaction temperature and combined in-line with particulate catalyst 123 contained in a particulate catalyst vessel 3228 in fluid communication with the preheated mixed gas stream 3232. Valves 108G and 108J are operated continuously or discontinuously to provide, such as by gravitational and/or venturi flow, a metered amount of particulate catalyst particles 123 into the gas stream 3232. The velocity of the gas stream 3232 and particle size of the particulate catalyst particles are selected to entrain at least most of the catalyst particles in the gas stream. Typically, the gas stream velocity ranges from about 0.1 fps to about 1.0 fps and at least most of the catalyst particles have a size ranging from about 0.5 micrometers to 5 micrometers

A blower 109 is optionally positioned immediately upstream or downstream (as shown) of the catalyst introduction location to pressurize the gas before introduction into the reactor. Typically, the reactor system 3200 will use either the vacuum pump 3216 or blower 109 depending on the application. The advantage of the vacuum pump over the blower 109 is that the vacuum pump, in the case of a plugged or partially occluded separator 122, can provide a lower risk of increasing the operating pressure of the reactor over the desired operating pressure.

The preheated gas stream 3232 is fed into the reactor 3204, which can be any of the reactor configurations described above, where it interacts with the particulate catalyst 123 to produce the first and second intermediate carbonaceous products 125 and 114 and product or reacted gas 190. The preheated gas stream 3232 is typically heated to a temperature ranging from about 550 to about 850°C and input at a pressure ranging from about -100 KPa (when the vacuum pump 3126 is used to transport the reactant gas) to about 100 KPa (when the blower 109 is used to transport the reactant gas) and gas velocity ranging from about 0.015 to about 20 fps. The mixed hydrocarbon gas 113 is diffused or distributed substantially in the reactor and suspends or fluidizes the particulate catalyst by the turbulent gas flown. Carbonaceous materials, typically carbon nanomaterial and more typically carbon nanofiber materials, grow on the suspended particulate catalyst 123 and, when the materials reach a threshold size, the materials, under the force of the fluidizing gas, break off, are suspended by the fluidizing gas, and, when the fluidizing gas is discontinued, fall to the bottom of the reactor as the second intermediate carbonaceous product. In one implementation, the process is operated under conditions substantially minimizing break off of the material and causing the particulate catalyst 123 and attached carbonaceous material to be removed by the fluidizing gas from the reactor 3204 and into the particle separator 122 where they are separated from the gas as the first intermediate carbonaceous product 125.

The particle separator 122 can be any device that can separate gas from entrained particulates. In some implementations , the particle separator is a housing with cartridge type filter elements 191 that pass the reacted gas as the filtrate but retains entrained particles as the retentate with an automatic backpulse facilitated by backflush gas 3236, such as hydrogen gas being used to cause the retentate to be removed from the filter media of the cartridges. The filter media can be backpulsed periodically during production of the carbonaceous material by closing valves 108A, 108E, and 108F and opening valves 108B, 108D, and 108F. The back pulse on the cartridge type filter elements 191 using the backflush gas 3236 cleans the filter elements of any collected particulates and the removed particulates are collected in the product chamber 3250 as the first intermediate product 125 that is isolated from the reactor by closed valve 108F, thereby permitting the backpulse to be at a gas pressure of at least the pressure drop across the particle separator 122. After backpulsing is completed, valve 108D is optionally closed and valve 108F opened to discharge the collected first intermediate product 125 into the reactor 3204.

As noted above in connection with other embodiments, the second intermediate carbonaceous product 114 may exit the reactor via an opened valve, door, etc. at the

5 bottom of the reactor. In some implementations, valve 108H may be opened (e.g., may cycle open) for the product discharge phase, such as to allow the product to be removed from the reactor. The carbonaceous product may be collected in a reactor discharge bin (117, 118, or both), such as a reactor discharge bin 232 as described with reference to Fig. 2A. In some implementations, the reactor discharge bin may include or lead to a cooling

10 circuit. Valve 108C may be used to isolate reactor discharge bin 121 from reactor discharge bin 117 when valve 108H is opened.

EXPERIMENTAL

The following examples are provided to illustrate certain aspects, embodiments, 15 and configurations of the disclosure and are not to be construed as limitations on the disclosure, as set forth in the appended claims. All parts and percentages are by weight unless otherwise specified.

Example 1

A particulate catalyst was placed in a 5” quartz tube, which was heated by a 20 Thermacraft wrap-around electrical heater. Methane was flowed into one end of the quartz tube at a rate of 1, 2, or 3 cubic feet per minute (CFM) to form a fluidized bed of the catalyst, and the heater was activated to maintain a consistent temperature in all regions/zones within the quartz tube of 700 °C. The product gas was cooled by submerging a product gas portion of the reactor in a chilled water bath. The product gas 25 was then analyzed for hydrogen (H2) and methane (CH4) gas content after 5, 10, 15, 30, and 60 minutes to determine a relationship between the surface area of the reactor and the flow rate for a conventional fluidized bed. The results are given in Table 1 below.

Table 1

A number of variations and modifications of the disclosure can be used. It would be possible to provide for some features of the disclosure without providing others.

For example in one alternative embodiment, the inert gas curtain is provided by other nozzle or gas distribution system configurations, such as plural emitters positioned around a periphery of the conduit 512.

In another alternative embodiment, the gas distribution assembly comprises one or more gas distributors and rotates about a longitudinal axis of the reactor and/or gas impermeable structure. In another alternative embodiment, the reactor assembly is used as a fluidized bed reactor for other chemical processes and reactions, such as in the petroleum and chemical processing industries. For example, the fluidized bed reactor can be used for cracking and reforming of hydrocarbons (oil), carbonization and gasification of coal, ore roasting, Fischer-Tropsch synthesis, polyethylene manufacturing, limestone calcining, aluminum anhydride production, granulation, vinyl-chloride production, combustion of waste, nuclear fuel preparation, combustion of solid, liquid and gaseous fuels, drying, adsorption, cooling, heating, freezing, conveying, storing and thermal treating of various particulate solid materials.

In another alternative embodiment, the cone can have other geometrical configurations. Examples comprise frustoconical, triangular prism, rectangular-based pyramid, tetrahedron, cylindrical prism, sphere, rectangular prism, pentagonal prism, hexagonal prism, octagonal prism, other polygonal prisms, and other volumetric shapes configured to provide vortex gas flow. The sidewalls of the prism or other volumetric shape can be tapered to provide for more turbulent vortex gas flow. The present disclosure, in various aspects, embodiments, and configurations, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various aspects, embodiments, configurations, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the various aspects, aspects, embodiments, and configurations, after understanding the present disclosure. The present disclosure, in various aspects, embodiments, and configurations, includes providing devices and processes in the absence of items not depicted and/or described herein or in various aspects, embodiments, and configurations hereof, including in the absence of such items as may have been used in previous devices or processes, e g., for improving performance, achieving ease and\or reducing cost of implementation.

The foregoing discussion of the disclosure has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the disclosure are grouped together in one or more, aspects, embodiments, and configurations for the purpose of streamlining the disclosure. The features of the aspects, embodiments, and configurations of the disclosure may be combined in alternate aspects, embodiments, and configurations other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed aspects, embodiments, and configurations. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

Moreover, though the description of the disclosure has included description of one or more aspects, embodiments, or configurations and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative aspects, embodiments, and configurations to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.

Claims

What is claimed is:

1. A reactor system comprising: a reaction vessel comprising an inlet for a hydrocarbon-containing gas and an outlet for a reacted gas stream; a gas impermeable structure comprising a continuous sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas through the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, the reaction vessel and gas impermeable structure having a common longitudinal axis; one or more gas distributors positioned to cause the hydrocarbon-containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel; and a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials.

2. The reactor system of claim 1, wherein a hydrocarbon in the hydrocarbon- containing gas catalytically decomposes into carbon nanofibers and hydrogen gas, wherein the one or more gas distributors comprise one or more gas injectors of the hydrocarbon- containing gas and/or one or more rotatable surfaces.

3. The reactor system of claim 1, wherein the continuous sidewall is arcuate and wherein the gas impermeable structure comprises an open cylinder centered about a longitudinal axis of a reactor cylindrical sidewall.

4. The reactor system of claim 1, further comprising a quiet zone at an upper end of the reaction vessel between the first end of the gas impermeable structure and an opposing upper surface of the reaction vessel and wherein a velocity of the hydrocarbon- containing gas in the quiet zone is less than a gas velocity required to entrain at least about 5% of the catalyst particulates in the bed of catalyst particulates.

5. The reactor system of claim 4, wherein a pressure of the hydrocarbon- containing gas ranges from about -100 KPa to about 100,000 KPa, wherein a first velocity of the hydrocarbon-containing gas in the hollow interior volume ranges from about 0.015 to about 20 fps a second velocity of the hydrocarbon-containing gas in the quiet zone ranges from about 0.15 to about 20 fps, and wherein a third velocity of the hydrocarbon- containing gas in the fluidized bed ranges from about 0.015 to about 20 fps, wherein a temperature of the hydrocarbon-containing gas in the fluidized bed ranges from about 550 to about 850 °C, wherein a P90 size of particulate catalyst particles ranges from about 0.1 to about 5 microns, and wherein the gas impermeable structure is an open cylinder with the first and second ends of the gas impermeable structure being spaced from a respective opposing surface of the reaction vessel.

6. The reactor system of claim 1, wherein, in a first mode, the gas impermeable structure is in a first position that is hermetically sealed to enable catalytic decomposition of hydrocarbons and, in a second mode, the gas impermeable structure is in a different second position that is not hermetically sealed to enable removal of carbonaceous material from the reaction zone.

7. The reactor system of claim 1, further comprising a vacuum pump positioned between a heat exchanger and pressure swing absorption system that creates a partial vacuum to cause flow of the reacted gas stream, wherein the heat exchanger transfers heat from reacted gas stream to the hydrocarbon-containing gas, and wherein the vacuum pump is in fluid communication with the outlet of the reaction vessel.

8. A method comprising: introducing a hydrocarbon-containing gas into an inlet of a reaction vessel, the reaction vessel comprising: a gas impermeable structure comprising a sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon- containing gas through the hollow interior volume, and discharges the hydrocarbon- containing gas through a second end; one or more gas distributors positioned to cause the hydrocarbon-containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel; and a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials.; removing a reacted gas from an exit gas conduit of the reactor; and removing a composite material comprising carbonaceous product and catalyst particles from an outlet of the reactor.

9. The method of claim 8, wherein the continuous sidewall is arcuate, wherein a hydrocarbon in the hydrocarbon-containing gas catalytically decomposes into carbon nanofibers and hydrogen gas, wherein the one or more gas distributors comprise one or more gas injectors of the hydrocarbon-containing gas and/or one or more rotatable surfaces, wherein the hydrocarbon-containing gas comprises at least about 50 mole % methane and hydrogen gas, and wherein the hydrocarbon-containing gas is at least substantially free of molecular oxygen and other oxidants..

10. The method of claim 8, wherein the gas impermeable structure comprises one of an elliptic and circular cylinder and wherein the sidewall is a surface of the one of an elliptic and circular cylinder, and wherein the one of an elliptic and circular cylinder is substantially centered about a longitudinal axis of a reactor cylindrical sidewall.

11. The method of claim 8, wherein the one or more gas distributors comprise one or more rotatable blades and further comprising: removing by a particle separator substantially all of any entrained catalyst particulates from the reacted gas; thereafter passing the reacted gas and the hydrocarbon-containing gas through a heat exchanger to transfer heat form the reacted gas to the hydrocarbon-containing gas to provide a cooled reacted gas and preheated hydrocarbon-containing gas; passing the cooled reacted gas through a vacuum pump to create a vacuum that causes the reacted gas to flow through the particle separator; and after passing through the vacuum pump, passing the cooled reactor gas through a pressure swing absorption system to separate form a separated hydrocarbon-containing gas stream comprising at least most of the unreacted hydrocarbon in the cooled reactor gas from byproduct hydrogen gas in the reacted gas and a separated hydrogen-containing gas stream comprising at least most of the byproduct hydrogen gas.

12. The method of claim 11, further comprising: combining the separated hydrocarbon-containing stream with the preheated hydrocarbon-containing gas to form a mixed gas stream; passing the mixed gas stream through a preheater to form a preheated mixed gas stream comprising the hydrocarbon-containing gas; combining the preheated mixed gas stream with the particulate catalyst at a gas velocity sufficient to entrain at least most of the particulate catalyst in the preheated mixed gas stream; and passing the preheated mixed gas stream comprising entrained particulate catalyst through the inlet of the reaction vessel, wherein the preheated mixed gas stream velocity prior to passing through the inlet is more than the preheated mixed gas stream velocity after passing through the inlet.

13. The method of claim 8, wherein a pressure of the hydrocarbon-containing gas ranges from about -100 to about 100,000 KPa, wherein a first velocity of the hydrocarbon-containing gas in the hollow interior volume ranges from 0.015 to about 20 fps, a second velocity of the hydrocarbon-containing gas upon discharge from the gas distributor ranging from about 0.015 to about 20 fps, and wherein a third velocity of the hydrocarbon-containing gas in the reaction zone ranges from about 0.015 to about 20 fps, wherein a temperature of the hydrocarbon-containing gas in the reaction zone ranges from about 550 to about 850 °C, wherein a P90 size of particulate catalyst particles ranges from about 0.1 to about 5 microns, wherein the gas impermeable structure is a cone, and wherein a ratio of a height (H) of the cone versus a cone diameter (D) ranges from about

1 : 1 to about 6: 1.

14. The method of claim 8, wherein the removing of the composite material comprises: moving the gas impermeable structure from a first position that is hermetically sealed to enable catalytic decomposition of hydrocarbons to a different second position that is not hermetically sealed to enable removal of composite material from the reaction zone.

15. The method of claim 8, wherein the reaction vessel comprises a quiet zone at an upper end of the reaction vessel between the first end of the gas impermeable structure and an opposing upper surface of the reaction vessel and wherein a velocity of the hydrocarbon-containing gas in the quiet zone is less than a gas velocity required to entrain at least about 5% of the catalyst particulates in the bed of catalyst particulates to substantially inhibit entry of entrained catalyst particles into the exit gas conduit; and during the introducing, rotating the one or more gas distributors around a longitudinal axis of the gas impermeable structure; separating the carbonaceous material from the catalyst particles to form a carbonaceous product; and recycling the catalyst particles to the introducing.

16. A reactor system comprising: a reaction vessel comprising an inlet for a hydrocarbon-containing gas and an outlet for a reacted gas stream; a gas impermeable structure comprising a continuous sidewall having a hollow interior volume that receives the hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas through the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, the reaction vessel and gas impermeable structure having a common longitudinal axis; one or more rotatable blades having an axis of rotation along the common longitudinal axis to cause the hydrocarbon-containing gas to flow downwardly through the first end, hollow interior volume, and second end and upwardly through an annular volume between the gas impermeable structure and the reaction vessel; a bed of catalyst particulates positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulates to produce nanomaterials; and a quiet zone at an upper end of the reaction vessel between the first end of the gas impermeable structure and an opposing upper surface of the reaction vessel, wherein a velocity of the hydrocarbon-containing gas in the quiet zone is less than a gas velocity required to entrain at least about 5% of the catalyst particulates in the bed of catalyst particulates.

17. The reactor system of claim 16, wherein a hydrocarbon in the hydrocarbon- containing gas catalytically decomposes into carbon nanofibers and hydrogen gas, wherein the one or more gas distributors comprise one or more gas injectors of the hydrocarbon- containing gas and/or one or more rotatable surfaces.

18. The reactor system of claim 16, wherein the continuous sidewall is arcuate, wherein a pressure of the hydrocarbon-containing gas ranges from about -100 KPa to about 100,000 KPa, wherein a first velocity of the hydrocarbon-containing gas in the hollow interior volume ranges from about 0.015 to about 20 fps a second velocity of the hydrocarbon-containing gas in the quiet zone ranges from about 0.15 to about 20 fps, and wherein a third velocity of the hydrocarbon-containing gas in the fluidized bed ranges from about 0.015 to about 20 fps, wherein a temperature of the hydrocarbon-containing gas in the fluidized bed ranges from about 550 to about 850 °C, wherein a P90 size of particulate catalyst particles ranges from about 0.1 to about 5 microns, and wherein the gas impermeable structure is an open cylinder with the first and second ends of the gas impermeable structure being spaced from a respective opposing surface of the reaction vessel.

19. The reactor system of claim 16, wherein, in a first mode, the gas impermeable structure is in a first position that is hermetically sealed to enable catalytic decomposition of hydrocarbons and, in a second mode, the gas impermeable structure is in a different second position that is not hermetically sealed to enable removal of carbonaceous material from the reaction zone.

20. The reactor system of claim 16, further comprising a vacuum pump positioned between a heat exchanger and pressure swing absorption system that creates a partial vacuum to cause flow of the reacted gas stream, wherein the heat exchanger transfers heat from reacted gas stream to the hydrocarbon-containing gas, and wherein the vacuum pump is in fluid communication with the outlet of the reaction vessel.