Reactor and method for producing carbonaceous materials - Patents.com

Abstract

In an embodiment of the present disclosure, a fluidized bed reactor for decomposing gaseous hydrocarbons into nanofibers and other carbonaceous materials and hydrogen includes a gas-impermeable structure including a continuous sidewall having a hollow interior volume that receives a hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas into the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, wherein the reaction vessel and the gas-impermeable structure have a common longitudinal axis; one or more gas distributors positioned to cause the hydrocarbon-containing gas to flow downwardly through the first end, the hollow interior volume, and the second end, and upwardly through an annular volume between the gas-impermeable structure and the reaction vessel; and a bed of catalyst particulate matter positioned within the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 63 / 404,442, filed September 7, 2022, and U.S. Provisional Application No. 63 / 419,258, filed October 25, 2022, entitled "Reactor and Process for Producing Carbonaceous Materials," the entire disclosures of which are hereby incorporated by reference herein.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to reactors and methods for producing carbonaceous materials, and in particular to reactors and methods for producing carbon nanomaterials, specifically carbon nanofiber materials. [Background technology]

[0003] The pyrolysis 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 significantly lower than that required by the steam reforming process (approximately 190 kJ / mol). Furthermore, unlike steam reforming, the hydrogen produced by the pyrolysis of methane can be produced in an oxygen-free environment and does not involve the water-gas shift reaction, allowing the reaction to produce both high-purity carbon and a carbon monoxide-free hydrogen gas stream. CH4 + 75.6 kJ / mol → C + 2H2

[0004] Pyrolysis of natural gas has been used for many years to produce carbon black, with the resulting hydrogen gas used as a supplemental fuel for the process. These processes are usually carried out semi-continuously using two tandem reactors at high operating temperatures (typically around 1,400°C), but those skilled in the art have attempted to lower these operating temperatures through 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, for example, Marina A. Ermakova et al., "Decomposition of methane over iron catalysts at the range of moderate temperatures: the influence of the 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 (July 2001), which is incorporated herein by reference in its entirety.

[0005] Direct catalytic decomposition of methane offers two major advantages over thermal decomposition: (i) the operating temperature can be dramatically reduced from approximately 1,400 °C to at least as low as approximately 550 °C, thereby significantly lowering the energy input requirements of the process, and (ii) judicious use of catalysts can also produce a variety of high-value engineered carbon nanostructures, 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 practical (i.e., commercially and economically relevant), highly effective catalysts, which have not been available until now, are required. Such catalysts should exhibit high activity over long periods of time and continue to function in the presence of high concentrations of accumulated carbon.

[0006] Furthermore, catalytic decomposition of methane can be a variable process due to strict requirements for metal particle size and the tendency of reaction conditions to adversely affect catalyst morphology. Previous studies have shown that the highest yields of solid carbon are achieved when the catalyst has an average particle size of approximately 30–40 nm, but have also shown that nickel catalyst particles can undesirably agglomerate as soon as the catalyst comes into contact with methane. See, for example, MA 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), incorporated herein by reference in its entirety. This particle sintering behavior reduces catalytic activity. Thus, although the concept of producing carbon and hydrogen by catalytic decomposition of methane has attracted strong interest and demonstrated technical feasibility, consistently achieving the desired high-quality carbonaceous product has been elusive. Many previous approaches in the art have failed to provide any degree of control over the types of carbon nanomaterials produced, and as a result, the carbonaceous products of these approaches typically must be purified by difficult, expensive, and / or time-consuming chemical and physical processes, making them impractical for commercial applications.

[0007] Furthermore, most of the catalytic cracking of methane and other solid carbon producing reactors are fixed bed type, which has many drawbacks: a) The endothermic reaction reduces the surface temperature of the catalyst, leading to the slow to rapid formation of carbon solids on the active surface of the catalyst, thereby deactivating the catalyst, which ultimately leads to very low yields and a reactor configuration unsuitable for producing solid carbon structures. b) Stationary catalyst particles are covered with solid carbon nanomaterials, reducing the driving force for chemisorption of carbon molecules onto the catalyst surface. Summary of the Invention

[0008] These and other needs are addressed by the various aspects, embodiments and configurations of the present disclosure.

[0009] In one embodiment of the present disclosure, the rotating media fluidized bed reactor may include: a. hydrocarbon-containing gas inlet; b. a gas impermeable structure comprising a continuous sidewall and a hollow interior volume for receiving a hydrocarbon-containing gas; c. a plurality of gas distributors positioned around the periphery of the gas impermeable structure and in fluid communication with the hollow interior to receive at least a majority of the hydrocarbon-containing gas from the hollow interior volume and discharge the hydrocarbon-containing gas to a reaction zone located exterior to the gas impermeable structure to create a vortex fluid flow, the reaction zone including suspended catalyst particles for causing decomposition of hydrocarbons in the hydrocarbon-containing gas to form carbonaceous materials; and d. An outlet gas conduit for receiving a reactant gas, the outlet gas conduit having an inlet positioned substantially on the axis of the vortex fluid flow.

[0010] In one embodiment of the present disclosure, the method may include the following steps: 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 a hollow interior volume for receiving a hydrocarbon-containing gas; and c. A gas distributor positioned at the periphery of the gas-impermeable structure, in fluid communication with the hollow interior, receiving at least a majority of the hydrocarbon-containing gas from the hollow interior volume, and discharging the hydrocarbon-containing gas to a reaction zone located exterior to the gas-impermeable structure to create a vortex fluid flow, the reaction zone including suspended catalyst particles for causing decomposition of hydrocarbons in the hydrocarbon-containing gas to form carbonaceous materials. including, steps, d. Removing the reaction gas from the outlet gas conduit of the reactor; and e. Removing the composite material comprising the carbonaceous products and catalyst particles from the reactor.

[0011] In one embodiment of the present disclosure, the rotating media fluidized bed reactor may include: a. hydrocarbon-containing gas inlet; b. a gas impermeable structure comprising a continuous sidewall and a hollow interior volume for receiving a hydrocarbon-containing gas; c. a gas distributor positioned near the periphery of the gas-impermeable structure and in fluid communication with the hollow interior to receive at least a majority of the hydrocarbon-containing gas from the hollow interior volume and discharge the hydrocarbon-containing gas to a reaction zone located exterior to the gas-impermeable structure to create a vortex fluid flow, the reaction zone including suspended catalyst particles for causing decomposition of hydrocarbons in the hydrocarbon-containing gas to form carbonaceous materials; and d. An outlet gas conduit for receiving a reactant gas, the outlet gas conduit having an inlet positioned substantially on the axis of the vortex fluid flow.

[0012] To support the swirl pattern and provide better catalyst particle suspension, each gas distributor may include an upwardly angled inclined surface to direct the discharged hydrocarbon-containing gas upward along a flow path transverse to the central axis of the reactor and / or tangential to the continuous side wall of the gas-impermeable structure. Each of the plurality of gas distributors includes an inlet and an outlet, each of which may be oriented in a substantially vertical plane to avoid orifice blockage, and a passageway interconnecting the inlet and outlet, which may have an arc-shaped central axis.

[0013] The reactor may include a gas curtain generator positioned at the inlet of the outlet gas conduit for discharging a curtain gas in a flow direction transverse to the flow direction of the reactant gas to reduce the velocity of the reactant gas and substantially inhibit ingress of entrained catalyst particles into the outlet gas conduit.

[0014] In one embodiment of the present disclosure, the reactor system may include: a. a reaction vessel including an inlet for a hydrocarbon-containing gas and an outlet for a reaction gas stream; b. a gas-impermeable structure including a continuous sidewall having a hollow interior volume that receives a hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas into the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, wherein the reaction vessel and the gas-impermeable structure have a common longitudinal axis; c. one or more gas distributors positioned to direct a hydrocarbon-containing gas downwardly through the first end, the hollow interior volume, and the second end and upwardly through the annular volume between the gas-impermeable structure and the reaction vessel; and d. A bed of catalyst particulate matter positioned within the annular volume such that a hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials.

[0015] In one embodiment of the present disclosure, the method may include the following steps: a. introducing a hydrocarbon-containing gas into an inlet of a reaction vessel, the reaction vessel comprising: i. a gas impermeable structure including a sidewall having a hollow interior volume for receiving a hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas into the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end; ii. one or more gas distributors positioned to direct a hydrocarbon-containing gas downwardly through the first end, the hollow interior volume, and the second end and upwardly through the annular volume between the gas-impermeable structure and the reaction vessel; and iii. a bed of catalyst particulate matter positioned within the annular volume such that a hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials. including, steps, b. removing the reaction gas from the outlet gas conduit of the reactor; and c. Removing the composite material comprising the carbonaceous products and catalyst particles from the outlet of the reactor.

[0016] In one embodiment of the present disclosure, the reactor system may include: a. a reaction vessel including an inlet for a hydrocarbon-containing gas and an outlet for a reaction gas stream; b. a gas-impermeable structure including a continuous sidewall having a hollow interior volume that receives a hydrocarbon-containing gas through a first end, passes the hydrocarbon-containing gas into the hollow interior volume, and discharges the hydrocarbon-containing gas through a second end, wherein the reaction vessel and the gas-impermeable structure have a common longitudinal axis; c. one or more rotatable blades having axes of rotation along a common longitudinal axis that direct the hydrocarbon-containing gas to flow downwardly through the first end, the hollow interior volume, and the second end, and upwardly through the annular volume between the gas-impermeable structure and the reaction vessel; d. a bed of catalyst particulate matter positioned within the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials; and e. A quiet zone at the upper end of the reactor vessel between the first end of the gas-impermeable structure and the upturned surface of the reactor vessel, wherein the velocity of the hydrocarbon-containing gas in the quiet zone is less than the gas velocity required to entrain at least about 5% of the catalyst particulate material in the bed of catalyst particulate material.

[0017] The gas-impermeable structure in any of the above embodiments may have a number of three-dimensional shapes. For example, the gas-impermeable structure may comprise a polygonal prism, where the sidewalls are the surfaces of the polygonal prism. The gas-impermeable structure may comprise an arcuate sidewall, such as the sidewall of a cone or a frustoconical prism.

[0018] While any reaction can occur within the reactor system of the above embodiments, the reactor and method are typically used for catalytic decomposition of hydrocarbons in a hydrocarbon-containing gas into carbon nanofibers and hydrogen gas.

[0019] The gas distributor in any of the above embodiments may be stationary or may include a plurality of gas distributors positioned substantially uniformly around the periphery of the gas impermeable structure.

[0020] The gas distributor of any of the above embodiments may include one or more gas injectors for hydrocarbon-containing gas and / or one or more rotatable surfaces.

[0021] The gas distributor in any of the above embodiments may be rotatable and may rotate about the longitudinal axis of the reactor and / or the gas impermeable structure.

[0022] The continuous sidewall in any of the above embodiments may be arcuate, and the gas impermeable structure may comprise an open cylinder centered on the longitudinal axis of the reactor cylindrical sidewall.

[0023] The quiet zone in any of the above embodiments may be located at the upper end of the reactor vessel between the first end of the gas impermeable structure and the upturned surface of the reactor vessel. The velocity of the hydrocarbon-containing gas in the quiet zone is typically less than the gas velocity required to entrain at least about 5% of the catalyst particulate matter in the bed of catalyst particulate matter.

[0024] The operating conditions of the reactor system in any of the above embodiments depend on the particular implementation. The pressure of the hydrocarbon-containing gas is typically in the range of about -100 KPa to about 100,000 KPa, the first velocity of the hydrocarbon-containing gas in the hollow interior volume is typically in the range of about 0.015 to about 20 fps, the second velocity of the hydrocarbon-containing gas in the quiet zone is typically in the range of about 0.15 to about 20 fps, the third velocity of the hydrocarbon-containing gas in the fluidized bed is typically in the range of about 0.015 to about 20 fps, the temperature of the hydrocarbon-containing gas in the fluidized bed is typically in the range of about 550 to about 850°C, and the P of the particulate catalyst particles is typically in the range of about 0.015 to about 20 fps. 90 The diameter is typically in the range of about 0.1 to about 5 microns, the gas-impermeable structure is generally an open elliptical cylinder or cylinder, the first and second ends of the gas-impermeable structure are spaced apart from the respective opposing surfaces of the reaction vessel, and the ratio of the height (H) of the gas-impermeable structure to the diameter (D) or width (W) of the gas-impermeable structure is in the range of about 1:1 to about 6:1.

[0025] The reactor system of any of the above embodiments can use a bimodal technique for removing carbonaceous products: in a first mode, the gas-impermeable structure can be in a hermetically sealed first position to allow catalytic cracking of hydrocarbons, and in a second mode, the gas-impermeable structure can be in a different, non-hermetically sealed second position to allow removal of carbonaceous material from the reaction zone.

[0026] In any of the above embodiments, a vacuum pump can be positioned between the heat exchanger and the pressure swing absorption system to create a partial vacuum to induce flow of the reactant gas stream, the heat exchanger transfers heat from the reactant gas stream to the hydrocarbon-containing gas, and the vacuum pump is in fluid communication with the outlet of the reaction vessel.

[0027] The present disclosure can provide many advantages depending on the specific configuration. For example, vortex flow can provide higher slip velocity, which provides better heat and mass transfer. A quiet zone to suppress entrainment of particulate matter in the reaction gas can prevent clogging of the particle separator. A vacuum pump can maintain the operating pressure in the reactor within safe operating requirements. The reactor system can inexpensively produce nanofibers as a bulk material. The length of the nanofibers can be controlled by controlling the gas velocity in the reaction zone. That is, generally, higher fluidization gas velocity results in shorter nanofiber product length due to increased gas turbulence, while lower fluidization gas velocity results in longer nanofiber product length. The process can be either a continuous batch process or a continuous process depending on the implementation.

[0028] These and other advantages are apparent from the disclosure of aspects, embodiments and configurations contained herein.

[0029] 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. Each one of A, B, and C in the above expressions may be associated with elements such as X, Y, and Z, or with elements X1 through X2. n , Y1~Y m and Z1 to Z o When referring to a class of elements such as X, Y, and Z, the phrase refers to a single element selected from X, Y, and Z, a combination of elements selected from the same class (e.g., X1 and X2), and a combination of elements selected from two or more classes (e.g., Y1 and Z). o ) is intended to refer to

[0030] It should be noted that the term "a" or "an" entity refers to one or more of that entity. Thus, the terms "a" (or "an"), "one or more," and "at least one" may be used interchangeably herein. It should also be noted that the terms "comprising," "including," and "having" can be used interchangeably.

[0031] As used herein, the term "means" is to be given its broadest possible interpretation pursuant to 35 U.S.C. § 112(f) and / or § 112(6). Accordingly, any claim incorporating the term "means" is intended to encompass all structure, material, or acts defined herein, and all equivalents thereof. Furthermore, structures, materials, or acts, and equivalents thereof, are intended to include all that are described in this Summary of Disclosure, Brief Description of the Drawings, Detailed Description, Abstract, and the claims themselves.

[0032] Unless otherwise stated, all ingredient or composition levels refer to the active portion of that ingredient or composition and do not include impurities, e.g., residual solvents or by-products, that may be present in commercial sources of such ingredient or composition.

[0033] All percentages and ratios are calculated by total composition weight unless otherwise indicated.

[0034] It should be understood that every maximum numerical limitation given throughout this disclosure is deemed to include 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 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 every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. For example, the phrase "about 2 to about 4" includes the whole number and / or integer ranges of about 2 to about 3, about 3 to about 4, as well as each possible range based on real numbers (e.g., irrational and / or rational numbers), such as about 2.1 to about 4.9, about 2.1 to about 3.4, etc.

[0035] The foregoing is a simplified summary of the present disclosure to provide an understanding of some aspects thereof. This summary is neither an extensive nor an exhaustive overview of the present disclosure and its various aspects, embodiments, and configurations. It is intended not to identify key or critical elements of the present disclosure or to delineate the scope of the present disclosure, but rather to present selected concepts of the present disclosure in a simplified form as a prelude to the more detailed description that is presented below. It will be understood that other aspects, embodiments, and configurations of the present disclosure can utilize, alone or in combination, one or more of the features defined above or described in detail below. Also, while the present disclosure is presented in terms of exemplary embodiments, it should be understood that individual aspects of the present disclosure may be claimed separately.

[0036] The accompanying drawings are incorporated into and constitute a part of this specification to illustrate several examples of the present disclosure. These drawings, together with the description, explain the principles of the present disclosure. The drawings merely illustrate preferred and alternative examples of how the present disclosure may be made and used, and should not be construed as limiting the disclosure to only the examples shown and described. Further features and advantages will become apparent from the following more detailed description of various aspects, embodiments and configurations of the present disclosure, as illustrated by the drawings referenced below. [Brief explanation of the drawings]

[0037] [Figure 1A] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 1B] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 2A] FIG. 2 is a schematic diagram of the embodiment of FIG. 1. [Figure 2B] FIG. 2 is a front view of a reactor system according to the embodiment of FIG. 1. [Figure 3] FIG. 2C is a rear perspective view of the reactor system of FIG. 2B (reactor housing sidewalls omitted). [Figure 4]FIG. 2C is a top perspective view of the reactor system of FIG. 2B (reactor housing sidewalls omitted). [Figure 5] FIG. 2C is a cross-sectional front view of the reactor system of FIG. 2B. [Figure 6A] FIG. 2C is an exploded view of a portion of the reactor system of FIG. 2B. [Figure 6B] FIG. 6B is an assembly drawing of a portion of the reactor system shown in FIG. 6A. [Figure 7] FIG. 2C is a cross-sectional view of a portion of the reactor system of FIG. 2B. [Figure 8] FIG. 2C is a side view of a gas distribution device of the reactor system of FIG. 2B. [Figure 9] FIG. 8 is an exploded view of a portion of the reactor system shown in FIG. [Figure 10] FIG. 8 is a perspective exploded view of a portion of the reactor system shown in FIG. 7. [Figure 11] FIG. 2C is a cross-sectional view of a portion of the reactor system of FIG. 2B. [Figure 12] FIG. 2C is a perspective cross-sectional view of a portion of the reactor system of FIG. 2B. [Figure 13] FIG. 2C is a plan view of a gas distribution device of the reactor system of FIG. 2B. [Figure 14] FIG. 2C is an exploded view of a portion of the gas distribution device of the reactor system of FIG. 2B. [Figure 15] FIG. 2C is an exploded view of a portion of the gas distribution device of the reactor system of FIG. 2B. [Figure 16] FIG. 2C is a diagram of the gas distribution device and reactor cone of the reactor system of FIG. 2B. [Figure 17] FIG. 2C is a bottom view of the gas distribution device and reactor cone of the reactor system of FIG. 2B. [Figure 18] FIG. 2C is a side view of a portion of the gas distribution device and reactor cone of the reactor system of FIG. 2B. [Figure 19] FIG. 19 is a partial cross-sectional side view of a portion of the gas distribution apparatus and reactor cone of FIG. 18. [Figure 20] FIG. 19 is a cross-sectional side view of a portion of the gas distribution apparatus and reactor cone of FIG. 18. [Figure 21]19 is another cross-sectional side view of a portion of the gas distribution apparatus and reactor cone of FIG. 18. [Figure 22] FIG. 2C is a side view of a gas curtain generator of the reactor system of FIG. 2B. [Figure 23] FIG. 23 is a bottom view of the gas curtain generator of FIG. 22. [Figure 24] FIG. 23 is a top view of the gas curtain generator of FIG. 22. [Figure 25] FIG. 23 is a top cross-sectional view of the gas curtain generator of FIG. 22. [Figure 26] FIG. 23 is a bottom cross-sectional view of the gas curtain generator of FIG. 22. [Figure 27] FIG. 2C illustrates a first spatial position of the reactor cone device of the reactor system of FIG. 2B, which allows for removal of product and catalyst. [Figure 28] FIG. 2C illustrates a second spatial position of the reactor cone device of the reactor system of FIG. 2B, which allows for catalytic production of product. [Figure 29A] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 29B] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 30] 30A and 30B are cross-sectional views of a reactor along a longitudinal bisecting plane according to one embodiment of the present disclosure. [Figure 31A] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 31B] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 32] FIG. 1 is a block diagram of a reactor system according to one embodiment of the present disclosure. [Figure 33] FIG. 30C is a cross-sectional view of the reactor of FIGS. 30A and 30B taken along the transverse bisecting plane according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0038] In an embodiment of the present disclosure, a stationary chamber rotating media fluidized bed reactor for cracking gaseous hydrocarbons into nanofibers and other carbonaceous materials and hydrogen is described. The reactor may have a stationary or rotating gas distributor containing angled slots and / or precision orifices to create a slip velocity vortex of the reactant gas flow around a gas-impermeable cone. "Slip velocity vortex" refers to a swirling flow pattern that includes hydrocarbon gas and particulate catalyst and provides a slip velocity, or 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 where the flow rotates around an axis, and the flow may be straight, curved, or curvilinear. While the embodiments discussed below refer to a static gas distribution assembly, it should be understood that the gas distribution assembly may also be configured to rotate around the longitudinal axis of a centrally positioned reactant gas outlet piping within the reactor.

[0039] In an embodiment of the present disclosure, a fluidized bed reactor for decomposing gaseous hydrocarbons into nanofibers and other carbonaceous materials and hydrogen gas incorporates a stationary or moving gas-impermeable open-ended baffle for positioning a fluidized bed in the annular space between the baffle and the reactor wall while leaving the interior volume of the baffle substantially free of catalyst particulate matter. To fluidize the bed, gas flow through the open baffle end, downward through the baffle interior volume, and upward through the annular space is provided by rotation of one or more blades having an axis of rotation substantially aligned with the common longitudinal axis of the baffle and the reactor.

[0040] It is also understood that in the above embodiments, innovation can be achieved either by pumping the reactant gases with a blower before the reactor or by a vacuum pump located at the outlet of the reactor, and either technique achieves the same reactant gas transport requirements.

[0041] 1A, one embodiment of a hydrocarbon gas decomposition reactor system 100 according to the present disclosure is depicted. The reactor system 100 includes a reactor 101, discussed in more detail below, in fluid communication with a particulate separator 122 and a heat exchanger (HX) 106 via a conduit 105. A fresh hydrocarbon feed or hydrocarbon gas 110 is preheated in the HX 106 to a temperature suitable for separation. The hydrocarbon gas decomposition reaction selectively produces first and second intermediate carbonaceous products 125 and 114 from the particulate catalyst 123 and the hydrocarbon gas 110.

[0042] Fresh hydrocarbon gas 110 is first preheated by waste heat from the product or reactant gas 190 in the HX 106. The preheated gas 110A then flows to a mixing (equalization) tank 104 and flows into a preheater 124 as a mixture 113 of fresh and recovered methane, where it is heated with hydrogen 111A, partially diverted from the hydrogen stream 111 recovered from pressure swing adsorption (PSA). PSA is a gas separation device well known in the industry that separates gas species from a mixture of gases under pressure according to the species' molecular properties and affinity for the adsorbent material. By controlling the pressure and temperature, a specific dew point can be set and the migration of one gas species from another can be retarded. Specifically, in this disclosure, the product gas 111 from the reactor 101 is a mixture of hydrogen and unreacted methane. In the recovery of methane from PSA, a "sweep" gas is typically used to remove methane from the PSA pressure vessel. Hydrogen (H) is typically used as a sweep gas and becomes part of the "recovered methane" gas. The PSA sends methane to equalization tank 104, where it is mixed with fresh methane. The mixed gas is preheated to the reaction temperature by preheater 124 and fed to the reactor as preheated mixed gas stream 126. The hydrocarbon gas can be any gaseous hydrocarbon, with shorter chain hydrocarbon gases, such as gases from the alkane group (e.g., methane, ethane, propane, butane, pentane, and hexane), being typical, and methane being more typical. The hydrocarbon gas can also be any gas from the alkene group (carbon-carbon double bond), alkyne group (carbon-carbon triple bond), or 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 remainder being nitrogen, hydrogen, or carbon dioxide gas. To avoid oxidation of the carbonaceous material formed on the particulate catalyst 123, the gas in 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 percent molecular oxygen and other oxidants.

[0043] The particulate catalyst 123 can be any metal 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 concurrently filed U.S. application Ser. No. 63 / 225,733, entitled "Catalyst for the Generation of Graphitic Non-Oxides and CO2-Free Hydrogen." The particulate catalyst 123 typically ranges from about 0.10 to about 5.0 microns. 90 It has a diameter.

[0044] The particle separator 122 can be any device capable of separating gas from entrained particulate matter. In one implementation, the particle separator 122 is a cyclone separator that uses the principles 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. Lighter components of the gas have lower inertia and are therefore more susceptible to being affected by the vortex and tend to rise up the vortex. Conversely, heavier components of the particulate matter have higher inertia and are less easily affected by the vortex. In one implementation, the particle separator 122 is a centrifuge. Like a cyclone, a centrifuge rotates objects around a central axis. This rotation pushes denser materials harder than less dense materials, separating objects by their density.

[0045] In some implementations, the particle separator is a housing containing a cartridge-type filter element 191 that passes the reaction gas as filtrate but retains entrained particles as retentate, and an automatic back-pulse facilitated by preheated hydrogen gas 109A is used to remove the retentate from the cartridge's filter media. The filter media may be back-pulsed periodically during production of the carbonaceous material by opening valve 108B and closing valve 108A, temporarily interrupting the fluid connection between the reactor 101 and the heat exchanger 106. The initial intermediate carbonaceous product 125 (filtered solids) from the back-pulse is directed back into the reactor chamber.

[0046] The mixed hydrocarbon gas 113 and hydrogen 111A are preheated by a preheater 124 and fed to the reactor 101, where they interact 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 is input at a pressure ranging from about -100 KPa (if a vacuum pump is used to transport the reactant gas) to about 100 KPa (if a blower is used to transport the reactant gas), and a gas velocity ranging from about 0.015 to about 20 fps. The mixed hydrocarbon gas 113 is substantially diffused or distributed within the reactor, suspending or fluidizing the particulate catalyst by forming a vortex pattern. Carbonaceous material, typically carbon nanomaterial, more typically carbon nanofiber material, grows on the suspended particulate catalyst 123; when the material reaches a threshold size, it breaks under the force of the fluidizing gas, becomes suspended by the fluidizing gas, and falls to the bottom of the reactor as a second intermediate carbonaceous product when the fluidizing gas is stopped. In one implementation, the process is operated under conditions that substantially minimize breakage of the material, and the particulate catalyst 123 and attached carbonaceous material are removed from the reactor 101 by the fluidizing gas and enter the particle separator 122, where they are separated from the gas as a first intermediate carbonaceous product 125. The first intermediate product 125 is returned to the reactor 101 by back-pulsing the cartridge-type filter element 1913 with hydrogen gas 109A.

[0047] In another embodiment, the cartridge-type filter element 191 of the particle separator 122 (FIG. 1B) is suspended within the reactor, and the back pulse simply drops the first intermediate carbonaceous product back into the reactor 101. In this embodiment, the external particle separator 122 is typically not utilized.

[0048] 2A , substantially minimizing the volume of particles exiting the reactor and entering the particle separator 122 provides a quiescent mechanism that inhibits the particulate catalyst 123 and intermediate carbonaceous products from exiting the reactor 101. Through 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 countercurrent gas flow within the conduit 112, causing a reduction in gas velocity within the quiescent zone 201. As discussed below, the reduced gas velocity is less than the gas velocity required to entrain the particulate catalyst 123 and / or intermediate carbonaceous products, thereby allowing the particles to remain within the reactor 101. As will be appreciated, the countercurrent velocity of the curtain gas 158 is less than the exit velocity of the gas in the gas flow conduit 112, more typically about 75% or less, and even more typically about 50% or less of the exit velocity.

[0049] Referring now to FIG. 2A, a more detailed embodiment of reactor system 200 is depicted.

[0050] An input gas compressor or blower 109 feeds preheated hydrocarbon gas 110 to the reactor via an input gas flow conduit 120 at a gas velocity typically ranging from about 0.015 to about 20 fps. Gas stream 126 is forced through a gas distributor assembly 204, including a cone 212 and a gas distributor system 216, at a first velocity (typically ranging from about 0.015 to about 20 fps), creating a vortex 208 from the inlet gas, which swirls around the cone 212 at a lower second velocity (typically ranging from about 0.015 to about 20 fps), as indicated by gas flow arrows 220 (which are typically substantially tangential to the curved surface of the cone 212). The reactor cone 212 provides a conical, gas-impermeable structure for the gas vortex 208 to rotate within.

[0051] The tapered, continuous sidewall of the cone 212 provides different cross-sectional flow areas for the region between the cone sidewall and the inner surface of the reactor 101. The gradually increasing, varying cross-sectional flow area from the base of the cone to the apex of the cone can provide different velocity zones and different slip velocities. In many applications, the lower velocity zone is near the base of the cone (typically in the range of about 10 to about 15% of the height H of the cone 212), the upper velocity zone is near the apex of the cone (typically above about 40% of the height H of the cone), and the intermediate velocity zone is located therebetween (typically in the range of about 15 to about 40% of the height H of the cone). The slip velocity in the lower velocity zone is typically less than that in the intermediate velocity zone, and the slip velocity in the upper velocity zone is typically greater than that in the intermediate and lower velocity zones. Although a continuously tapered sidewall of the cone 212 is shown in the figures, it should be understood that the sidewall may be discontinuously tapered or stepped to provide similar velocity zones.

[0052] The particulate catalyst 123 is placed in the reactor 101 prior to start-up or is fed through a feed chamber 3228 (see FIG. 32) during operation by venturi action caused by the reactant gas flow, and / or by a vortex 208 created by the gas distributor 216 to keep the particulate catalyst 125 particles (not shown) suspended in a reaction zone with a turbulent flow around the circumference of the cone 212. The gas stream 126 reacts with the particulate catalyst 123 particles suspended in the vortex 208, causing the particulate catalyst 123 particles to begin growing carbonaceous materials, such as graphite nanofibers, thereby increasing the weight of the catalyst particles. A curtain gas 158 is fed into the reactor 101 in a counterflow direction to the gas stream 126 via a top-down curtain gas flow conduit 224 positioned within the gas flow conduit 112 and a gas curtain generator 226 to form a gas curtain 228 with a third gas flow velocity less than the first and second gas flow velocities. The downward flow of curtain gas 158 effectively forms a low gas velocity curtain (typically with a curtain:feed flow rate ratio ranging from about 1:3 to about 1:6) to prevent particulate catalyst particles 123 from rising above the turbulence or reaction zone formed by vortex 208. A gaseous mixture 210 of unreacted hydrocarbon gas and gaseous by-products (e.g., hydrogen gas) and curtain gas exits vortex 208 as particle-free gas via recycle flow conduit 112.

[0053] Reactor discharge bin 232 is in fluid communication with reactor 101. Intermittently, when a sufficient amount of carbonaceous material breaks off from the turbulent flow over particulate catalyst 140 in gas vortex 208, input shaft 236 assists the sliding of gas distributor assembly 204 by sliding along discharge guide 240, and the combination of these functions tilts gas distributor assembly 204 to drop the carbonaceous material into bin 232, which is hermetically sealed to prevent oxygen from contacting the carbonaceous material.

[0054] The carbonaceous material is discharged from the discharge bin 232 using a jacketed cooling auger 244 driven by a motor 248. The second intermediate carbonaceous product 136 is discharged to a product storage tank 252 via an airlock 256 and a jacketed cooling auger 260 driven by a motor 264.

[0055] 2B and 3-5, a specific implementation of reactor system 200 is depicted. Cylindrical reactor 101, particle separator 122, and compressor or blower 109 are shown in fluid communication with one another via recycle flow conduits 112 and 116, input gas flow conduit 120, and recycle flow conduit 128. Referring to FIG. 5, recycle flow conduit 128 and recycle flow conduit 112 extend into the reactor interior, as indicated by first and second recycle conduit segments 500 and 504, respectively. A first inlet 508 of first recycle conduit segment 500 extends a shorter distance into the reactor interior than a second inlet 512 of second recycle conduit segment 504. That is, first inlet 508 is positioned above second inlet 512 to prevent premature removal of particulate catalyst particles 140 from the reaction zone. The second inlet 512 is positioned spatially proximate to the apex 516 of the cone 212, and in some implementations is positioned within the second inlet 512 and the second recycle conduit segment. The cone 212, the recycle flow conduit 112, and the second inlet 512 are centered about the longitudinal axis 272 of the reactor 101.

[0056] 2B and 3-5 includes a second reactor discharge bin 520 positioned below the particle separator 122 to receive the first intermediate carbonaceous product 125. The use of dual reactor discharge bins 232 and 520 allows lighter composite particles comprising particulate catalyst 140 and lighter carbonaceous material (e.g., shorter carbon nanofiber lengths) to be removed by using a gas flow rate (higher than the second gas flow rate) to blow the composite particles into the first inlet 508 and collect them as the first intermediate carbonaceous product 125 in the second reactor discharge bin 520, and heavier composite particles comprising particulate catalyst 140 and heavier carbonaceous material (e.g., longer carbon nanofiber lengths) to be removed by spatial movement of the gas distributor assembly 204.

[0057] 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, the gas distributor assembly 204 is fastened to the base of the reactor 101 via a plurality of fasteners 606 and to the interior 1004 of the gas distribution system 216 via a flange assembly including a flange 600 and interconnected conduit segments 604. The inlet of the conduit segment 604 is connected to the outlet of an elbow 608, the inlet of which movably engages the outlet of the input gas flow conduit 120. The inlet of the elbow 608 includes a gasket assembly 1000 to maintain an airtight seal between the elbow 608 and the input gas flow conduit 120.

[0058] The reactor assembly 100 operates in a first and second mode to discharge the second intermediate carbonaceous product 114 into the reactor discharge bin 232 .

[0059] 28, the gas distributor assembly 204, including the cone 212 and the gas distributor 216, engages the reactor 101 with an airtight seal, and the gasket assembly 1000 on the inlet of the elbow 608 engages the outlet of the input gas flow conduit 120 to form an airtight seal. The gas distributor assembly 204 and the conduit segment 604 are in a first spatial position relative to the length of the discharge guide 240. In this configuration, the reactor 101 is fluidized with the hydrocarbon gas 110, and graphite or carbon nanofibers are formed on the particulate catalyst 123.

[0060] 27, the gas distributor assembly is disengaged from (and no longer forms an airtight seal with) the reactor 101, and the gasket assembly 1000 on the inlet of the elbow 608 is disengaged from (and no longer forms an airtight seal with) the outlet of the input gas flow conduit 120. The gas distributor assembly 204 and the 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 within the reactor 101 can be discharged to the reactor discharge bin 232.

[0061] Any displacement mechanism can be used to selectively position the reactor assembly in either the first or second mode. For example, the input shaft 236 may engage a cam that is rotated to move the input shaft up or down. In another example, the input shaft is displaced pneumatically or hydraulically.

[0062] Although the ejection guide 240 is shown as a guide rail that movably engages a guide member 2700 (e.g., a protruding pin or wheel), any guide or linkage mechanism can be used, such as a linear slide mechanism including ball bearings that move along a shaft.

[0063] 7-8 and 13-21, the gas distributor assembly 204 is described. The gas distributor assembly 204 includes a plurality of gas injectors 1416 positioned at substantially uniformly spaced locations around the circumference of the interior 1004 of the gas distributor assembly 204. Holes 1300 positioned at substantially uniformly spaced locations around the circumference of the inlet 704 align with holes in the flange 600 and are configured to receive the fasteners 606.

[0064] The interior volume 700 of the cone 212 is at least substantially hollow, with the cone sidewalls impermeable to gas flow and acting as a manifold for hydrocarbon gas entering through the inlet 704, such that the hollow interior substantially equalizes the incoming hydrocarbon gas pressure before the gas passes through a plurality of inlet orifices 708, flows through respective interior passages 1400, and flows outward through respective output orifices 1404 in a substantially vertical surface 1406 and into the reactor interior volume. To provide smoother gas flow and reduced gas pressure loss, the passages 1400 are typically curved (e.g., arc-shaped, or possibly rounded) and do not have sharp angles. The exiting gas is directed by the ramp 1408 into the reactor interior along a flow path substantially parallel to the slope of the slope (typically in the range of about 1 to about 75 degrees, more typically about 1 to about 45 degrees, relative to the horizontal). The curved edge 1412 of each of the multiple gas injectors 1416 provides a smooth gas exit into the reactor interior.

[0065] Typically, the inlet and output orifices 708 and 1404 of each and every gas injector 1416, and each intervening passage 1400, are substantially the same diameter. The diameters are selected to provide an output gas velocity that is at least the terminal velocity of the particulate catalyst particles to maintain particle entrainment and inhibit particle collection at the substantially flat surface 1416 of the output orifice 1404 and clogging of the gas injector. Typically, the output gas velocity ranges from about 0.5 to about 20 fps.

[0066] The cone angle θ 2000 (FIG. 20) formed between the cone sidewall and the horizontal plane determines the speed of 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 θ is decreased to lower the gas velocity in the reaction zone, while to produce shorter graphite nanofibers, the angle θ is increased to increase the gas velocity in the reaction zone. In other words, the angle θ for longer graphite nanofibers is smaller than the angle θ for shorter graphite nanofibers. Typically, the angle θ 2000 ranges from about 1 to about 45 degrees, and the ratio of the cone height (H) to the cone diameter (D) (FIG. 8) ranges from about 1:1 to about 6:1.

[0067] 11 and 22-26, a gas curtain generator 1100 that emits a curtain gas curtain is described. The gas curtain generator 1100 is in fluid communication with a curtain gas supply conduit 1104 that connects to and forms an airtight seal with fitting 1108 on the generator 1100. The curtain gas flows through an inlet 2500, through a passage 2504 into an annular space 2508, and is emitted through an annular ring 1112, forming a gas curtain. As shown in FIG. 22, the diameter of the generator 1100 steps down from a first, larger diameter inlet 2200 that engages conduit segment 504 to a second, smaller diameter outlet 2204. The step-down is accomplished using an intermediate section 2208 that gradually reduces in diameter from the first diameter to the second diameter.

[0068] In another embodiment of the reactor design shown in Figures 29A-B and 30A-B, turbulent flow 208 is generated by internal recirculation of the feed gas. Unlike the reactor designs discussed above, in which turbulent flow 208 is in a substantially helical flow path around the periphery of cone 212 (e.g., in a flow path transverse to the longitudinal axis of the reactor), turbulent flow 208 is in a substantially vertical plane (e.g., in a plane substantially parallel to the longitudinal axis of the reactor) due to the open upper and lower ends of baffle 301. Baffle 301 and reactor 300 may have any desired curved and / or angular and / or curvilinear transverse or longitudinal cross-sectional shape, but the shapes of baffle 301 and reactor 300 should be the same. Common cross-sectional shapes include elliptical or cylindrical. For example, as shown in Figure 33, baffle 301 with a cylindrical transverse cross-section is used in a reactor that also has a cylindrical transverse cross-section. The distance "D" between the outer wall of the baffle and the inner wall of the reactor is substantially constant around the circumference of the baffle. As shown by FIG. 33, the cylindrical baffle 301 and the 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 allow gas to flow upwardly (as indicated by flow arrows 314) externally against the baffle (gas-impermeable) sidewall 316 and downwardly internally, around the baffle's upper and lower ends 308 and 312, as shown. The reactor 300 includes a fan assembly including a motor 303 in operative communication with one or more fan blades 320 via a drive shaft 324 to circulate gas within the reactor 300 in the manner described. Gas is continuously circulated within the reactor by rotation of one or more fan blades 320, typically in a counterclockwise direction, to fluidize a bed of particulate catalyst particles located in a reaction zone 328 located between the sidewall 316 and the reactor 300 wall. Typically, the open lower end of the baffle and the baffle interior volume 330 are substantially free of catalyst particles. All external configurations remain the same.Although reactor 300 is described with specific reference to a fan assembly, other methods for inducing a fluidizing gas flow may be used, including the gas injectors described above positioned at the upper end 308 of the reactor or at the lower end of the reactor in the reaction zone outside the sidewall 316.

[0069] The quiet zone 390 is not formed using a gas curtain, as in the case of the quiet zone 201. Instead, the quiet zone 390 is formed by careful control of the gas velocity within the reactor 300 combined with the turbulence 208 pattern (forming vortices that can prevent particulate matter 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 products, thereby causing the particles to remain within the reactor 300. As will be appreciated, the gas flow is typically maintained at a velocity no greater than about 90%, more typically no greater than about 80%, of the velocity required to entrain unreacted catalyst particulate matter. As carbon nanomaterials form on the catalyst particles, the particles become heavier, requiring higher velocities for entrainment. The highest levels of particulate matter entrainment typically occur when fresh catalyst particulate matter is introduced into the reactor 300. The dimensions of the quiet zone typically depend on the vertical gas velocity, the size and weight / density of the particulate matter, the diameter of the reactor, and the like.

[0070] In another embodiment of the reactor design shown in FIGS. 31A-B, a product discharge stage (e.g., a carbon discharge stage) may be deployed to remove composite materials, including carbonaceous products and / or catalyst particles (e.g., first or second intermediate carbonaceous products 125 and 114), from the reactor. The product discharge stage may be achieved by reversing the flow of the fan assembly, typically in a clockwise direction (e.g., by reversing the orientation of fan blades 320), reversing the flow pattern of the reactor. Additionally, inlets 103, 105, 326, or a combination thereof, may be sealed. In one embodiment, inlets 103 and 105 may be sealed, and inlet 326 may remain open during the product discharge stage. In some implementations, inlets 103 and 105 may be open during the catalyst feed cycle and remain closed at all other times, such as during the product discharge stage. In one embodiment with reference to FIG. 31A, inlet 326 and valve 108A may be closed during the product discharge stage. In one embodiment, referring to FIG. 31B, valve 108A may be closed and inlet 326 may remain open during the product discharge stage.

[0071] Thus, during production of the carbonaceous product, as in a batch reactor design, one or more inlets (e.g., inlets 103, 105, and 326) and / or one or more valves (e.g., valve 108A) may be closed (e.g., sealed), and the flow of the fan assembly may be reversed. During the product discharge phase, and in response to the reversal of the fan direction, countercurrent gas flow may flow downward through the center of the filter housing (as depicted in Figures 31A-31B) to the exterior and upward through the interior (which is typically hydrogen gas). Thus, the carbonaceous product may flow downward. The carbonaceous product may then exit the reactor through an open valve, door, or the like at the bottom of the reactor. In some implementations, referring to Figures 31A and 31B, line 322 may be open (e.g., periodically open) during the product discharge phase, for example, to allow the product to be removed from the reactor. The carbonaceous products may be collected in a reactor discharge bin (117, 118, or both), such as reactor discharge bin 232 as described with reference to FIG. 2A. In some implementations, the reactor discharge bin may include or be connected to a cooling circuit.

[0072] The reactor designs of Figures 29A, 30A and 31A may have the external filter reactor configuration described above, while the reactor designs of Figures 29B, 30B and 31B may have the internal filter reactor configuration also described above.

[0073] While the reactor designs of Figures 29A, 30A, and 31A may employ baffles having open top and / or bottom ends spaced from the opposing interior walls of the reactor vessel as shown in the figures, it is understood that the open-end configuration may be achieved with other baffle configurations. For example, the gas-permeable top or bottom of the baffle may be positioned adjacent to the gas-impermeable center of the baffle. Gas permeability may result from a perforated or vented surface having one or more openings, apertures, orifices, ports, or other holes for passing a gas stream. In some configurations, the opening size may be adjusted to a value equal to the mean, mean, median, or P of catalyst particulate matter prior to substantial nanomaterial formation in order to maintain the baffle interior substantially free of catalyst particulate matter. 50 Or P 25 The gas permeable upper or lower portion may be connected to the upper or lower wall of the reactor vessel or may be spaced apart from the wall. The gas permeable upper or lower portion may be positioned over only a portion or all of the upper or lower end of the baffle.

[0074] Another embodiment of a reactor system 3200 is shown in Figure 32. The reactor system 3200 includes a reactor 3204 (which may be any of the reactor configurations discussed above) in fluid communication with a particulate separator 122 and a multi-stage heat exchanger (HX) 106 via a conduit 3208. Fresh hydrocarbon feed or hydrocarbon gas 110 (typically primarily methane and / or other short-chain hydrocarbons) is preheated in the HX 106 to a temperature suitable for separation. The hydrocarbon gas cracking reaction selectively produces first intermediate and second intermediate carbonaceous products 125 and 114 from the particulate matter catalyst 123 and the hydrocarbon gas 110.

[0075] The hydrocarbon gas 110 is first preheated by waste heat from the product or reactant gas 190 (which is a mixture of unreacted methane and / or other short-chain hydrocarbons and by-product hydrogen gas) in the HX 106 to form a preheated hydrocarbon gas 3208 and a cooled reactant gas 3212. The cooled reactant gas 3212 optionally passes through a vacuum pump 3216 to create a partial vacuum and provide the driving force for the gas to 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 cooler gas stream. The vacuum pump 3216 may be any type of vacuum pump, such as a positive displacement, momentum transfer, or entrainment vacuum pump. The cooled reactant gas 3212 then flows into a compressor 3220 which compresses the gas, which is primarily a mixture of unreacted methane and / or other short chain hydrocarbons and by-product hydrogen gas, for separation into a hydrogen gas-containing stream 111 recovered by the PSA 107 and a separated hydrocarbon-containing stream 115. The PSA 107 is in fluid communication with a chiller 3224 which uses a coolant to maintain the PSA 107 within a desired operating temperature range.

[0076] 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 the mixed gas stream 113. Optionally, a bleed stream of the recovered hydrogen stream 111 can be introduced into the equalization tank 104 to provide the desired gas mixture. Typically, the mixed gas stream contains from about 70 to about 100 mole % methane and / or other short chain hydrocarbons, and from about 30 to about 0 mole % hydrogen (H (2) ) is included.

[0077] The mixed gas is preheated to a reaction temperature by a preheater 124 and coupled in-line with particulate catalyst 123 contained in a particulate catalyst container 3228 in fluid communication with the preheated mixed gas stream 3232. Valves 108G and 108J are operated continuously or discontinuously to provide a metered amount of particulate catalyst particles 123 to the gas stream 3232, such as by gravity and / or venturi flow. The velocity of the gas stream 3232 and the particle size of the particulate catalyst particles are selected to entrain at least a majority of the catalyst particles in the gas stream. Typically, the velocity of the gas stream is in the range of about 0.1 fps to about 1.0 fps, and at least a majority of the catalyst particles have a size in the range of about 0.5 micrometers to 5 micrometers.

[0078] 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, reactor system 3200 uses either a vacuum pump 3216 or a blower 109 depending on the application. The advantage of a vacuum pump over a blower 109 is that it can reduce the risk of raising the operating pressure of the reactor above the desired operating pressure if separator 122 is clogged or partially blocked.

[0079] The preheated gas stream 3232 is fed to a reactor 3204, which may be any of the reactor configurations described above, where it interacts with the particulate catalyst 123 to produce first and second intermediate carbonaceous products 125 and 114 and a product or reactant gas 190. The preheated gas stream 3232 is typically heated to a temperature ranging from about 550 to about 850°C, and is input at a pressure ranging from about -100 KPa (if a vacuum pump 3126 is used to transport the reactant gas) to about 100 KPa (if a blower 109 is used to transport the reactant gas), and at a gas velocity ranging from about 0.015 to about 20 fps. The mixed hydrocarbon gas 113 is substantially diffused or distributed within the reactor, suspending or fluidizing the particulate catalyst with the turbulent flowing gas. Carbonaceous material, typically carbon nanomaterial, more typically carbon nanofiber material, grows on the suspended particulate catalyst 123, and when the material reaches a threshold size, it breaks down under the force of the fluidizing gas, becomes suspended by the fluidizing gas, and falls to the bottom of the reactor as a second intermediate carbonaceous product when the fluidizing gas is stopped. In one implementation, the process is operated under conditions that substantially minimize breakage of the material, and cause the particulate catalyst 123 and attached carbonaceous material to be removed from the reactor 3204 by the fluidizing gas and enter the particle separator 122, where it is separated from the gas as a first intermediate carbonaceous product 125.

[0080] The particle separator 122 may be any device capable of separating gas from entrained particulate matter. In some implementations, the particle separator is a housing containing a cartridge-type filter element 191 that passes the reactant gas as a filtrate but retains entrained particles as a retentate. An automatic back-pulse facilitated by a back-flush gas 3236, such as hydrogen gas, is used to remove the retentate from the cartridge's filter media. The filter media may be back-pulsed periodically during carbonaceous material production by closing valves 108A, 108E, and 108F and opening valves 108B, 108D, and 108F. Back-pulsing the cartridge-type filter element 191 using the back-flush gas 3236 washes the collected particulate matter from the filter element, and the removed particulate matter is collected in the product chamber 3250 as the first intermediate product 125 isolated from the reactor by closed valve 108F, thereby allowing the back-pulse to create a gas pressure drop across at least the particle separator 122. After the backpulse is completed, valve 108D is optionally closed and valve 108F is opened to discharge the collected first intermediate product 125 into reactor 3204.

[0081] As described above in connection with other embodiments, the second intermediate carbonaceous product 114 may exit the reactor through an open valve, door, etc. at the bottom of the reactor. In some implementations, valve 108H may be open (e.g., may open periodically) during a product discharge phase, for example, 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 reactor discharge bin 232 as described with reference to FIG. 2A. In some implementations, the reactor discharge bin may include or be connected to a cooling circuit. Valve 108C may be used to isolate reactor discharge bin 121 from reactor discharge bin 117 when valve 108H is open.

[0082] experiment The following examples are provided to illustrate certain aspects, embodiments, and configurations of the present disclosure and are not to be construed as limitations on the present disclosure, as defined in the appended claims. All parts and percentages are by weight unless otherwise specified. [Example]

[0083] [Example 1] The particulate catalyst was placed in a 5" quartz tube, which was heated by a Thermacraft wraparound electric heater. Methane was flowed into one end of the quartz tube at rates of 1, 2, or 3 cubic feet per minute (CFM) to form a fluidized bed of catalyst, and the heater was activated to maintain a constant temperature of all regions / zones within the quartz tube at 700°C. The product gas was cooled by immersing the product gas section of the reactor in a cold water bath. The product gas was analyzed for hydrogen (H2) and methane (CH4) gas content after 5, 10, 15, 30, and 60 minutes to determine the relationship between reactor surface area and flow rate for a conventional fluidized bed. The results are shown in Table 1 below.

[0084] [Table 1]

[0085] Many variations and modifications of the present disclosure may be used. Some features of the present disclosure may be provided without providing other features.

[0086] For example, in one alternative embodiment, the inert gas curtain is provided by other nozzle or gas distribution system configurations, such as multiple emitters positioned around the periphery of the conduit 512 .

[0087] In another alternative embodiment, the gas distribution assembly includes one or more gas distributors and rotates about the longitudinal axis of the reactor and / or the gas impermeable structure.

[0088] 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, fluidized bed reactors may be used in hydrocarbon (oil) cracking and upgrading, coal carbonization and gasification, ore roasting, Fischer-Tropsch synthesis, polyethylene production, limestone calcination, anhydrous aluminum production, granulation, vinyl chloride production, waste combustion, nuclear fuel preparation, combustion of solid, liquid, and gaseous fuels, drying, adsorption, cooling, heating, freezing, transporting, storing, and thermally treating various particulate solid materials.

[0089] In other alternative embodiments, the cone may have other geometric configurations. Examples include a truncated cone, a triangular prism, a rectangular-based pyramid, a tetrahedron, a cylindrical prism, a sphere, a square prism, a pentagonal prism, a hexagonal prism, an octagonal prism, other polygonal prisms, and other volumetric shapes configured to provide a vortex gas flow. The sidewalls of the prism or other volumetric shapes can be tapered to provide a more turbulent vortex gas flow.

[0090] The present disclosure in its various aspects, embodiments, and configurations includes substantially all of the components, methods, processes, systems, and / or apparatus depicted and described herein, including various aspects, embodiments, configurations, subcombinations, and subsets thereof. After understanding the present disclosure, one of ordinary skill in the art will understand how to make and use the various aspects, aspects, embodiments, and configurations. The present disclosure in its various aspects, embodiments, and configurations includes providing devices and processes in the absence of items not depicted and / or described herein or in the various aspects, embodiments, and configurations herein, including the absence of items that may have been used in previous devices or processes, e.g., to improve performance, achieve ease, and / or reduce implementation costs.

[0091] The foregoing discussion of the present disclosure has been presented for purposes of illustration and description. The foregoing is not intended to limit the present disclosure to the form or forms disclosed herein. For example, in the foregoing Detailed Description, various features of the present disclosure are grouped together in one or more aspects, embodiments, and configurations for the purpose of streamlining the disclosure. Features of the aspects, embodiments, and configurations of the present disclosure may be combined into alternative aspects, embodiments, and configurations other than those discussed above. This method of disclosure should not 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 aspect, embodiment, or configuration. 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 present disclosure.

[0092] Furthermore, although the description of one or more aspects, embodiments, or configurations, as well as descriptions of specific variations and modifications, are included throughout the description of this disclosure, other variations, combinations, and modifications are within the scope of this disclosure, for example, as would be within the skill and knowledge of one of ordinary skill in the art after understanding this disclosure. It is intended to be entitled to include, to the extent permissible, alternative aspects, embodiments, and configurations, including such alternative, interchangeable, and / or equivalent structures, functions, ranges, or steps to those claimed, regardless of whether or not such alternative, interchangeable, and / or equivalent structures, functions, ranges, or steps are disclosed herein, and without any intention to dedicate patentable subject matter to the public. [Explanation of symbols]

[0093] 100 Reactor System 101 Reactor 103 Entrance 104 Mixing tank, equalization tank 105 Conduit, inlet 106 Heat exchanger 107 PSA 108A Valve 108B Valve 108C Valve 108D Valve 108E Valve 108F Valve 108G Valve 108H bulb 108J valve 109 Input gas compressor or blower 109A Preheated hydrogen gas 110 Hydrocarbon feed, hydrocarbon gas 110A Preheated Gas 111 Hydrogen Stream, Product Gas, Hydrogen Gas-Containing Stream 111A Hydrogen 112 Gas flow conduit, recycle flow conduit 113 Methane, mixed hydrocarbon gases, mixed gas streams 114 Second intermediate carbonaceous product 115 Hydrocarbon-containing streams 116 Recycle flow conduit 117 Reactor discharge bin 118 Reactor discharge bin 120 input gas flow conduit 121 Reactor discharge bin 122 Particle separator 123 Particulate catalyst 124 Preheater 125 First intermediate carbonaceous product, particulate catalyst 126 Preheated mixed gas stream 128 Recycle flow conduit 136 Second intermediate carbonaceous product 140 Particulate catalyst particles 158 Curtain Gas 190 Product or reaction gas 191 Cartridge-type filter element 200 Reactor System 201 Quiet Zone 204 Gas distributor assembly 208 Vortex, Turbulence 210 Gaseous mixtures 212 Cone 216 Gas distributor system, gas distributor, gas distribution system 220 Gas Flow Arrow 224 Curtain gas flow conduit 226 Gas Curtain Generator 228 Gas Curtain 232 Reactor discharge bin 236 Input shaft 240 Ejection Guide 244 Cooling Auger 248 Motor 252 Product storage tank 256 Airlock 260 Jacketed Cooling Auger 264 Motor 272 Longitudinal Axis 300 reactor 301 Baffle 303 Motor 308 Upper end 312 Lower end 314 Flow Arrow 316 Side wall 320 Fan Blade 322 Line 324 Drive shaft 326 Entrance 328 Reaction Zone 330 Baffle internal volume 390 Quiet Zone 500 First recycling pipeline segment 504 Second Recycling Pipe Segment 508 First Entrance 512 Second Entrance 516 Vertex 520 Second reactor discharge bin 600 flange 604 conduit segments 606 Fasteners 608 Elbow 700 internal volume 704 Entrance 708 Inlet Orifice 1000 Gasket Assembly 1004 Internal 1100 Gas Curtain Generator 1104 Curtain gas supply pipe 1108 Joint 1112 Annular Ring 1300 holes 1400 Internal passage 1404 Output orifice 1406 Substantially Vertical Surfaces 1408 ramp 1412 curved edge 1416 Gas injector, substantially flat surface 1913 Cartridge type filter element 2000 cone angle 2200 Entrance 2204 Exit 2208 Mid Section 2500 entrance 2504 Passage 2508 Annular Space 2700 Guide member 3200 Reactor System 3204 Reactor 3208 Conduits, preheated hydrocarbon gas 3212 Cooled reaction gas 3216 Vacuum pump 3220 Compressor 3224 Cooler 3228 Feed chamber, particulate catalyst container 3232 Preheated mixed gas stream 3236 Backflush gas 3250 Product Chamber

Claims

1. a reaction vessel including an inlet for a hydrocarbon-containing gas and an outlet for a reaction gas stream; a gas-impermeable structure including a continuous sidewall having a hollow interior volume for receiving the hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas into the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end, wherein the reaction vessel and the gas-impermeable structure have a common longitudinal axis; one or more gas distributors positioned to direct the hydrocarbon-containing gas downwardly through the first end, the hollow interior volume, and the second end and upwardly through an annular volume between the gas-impermeable structure and the reaction vessel; and a bed of catalyst particulate matter positioned within the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials. a reactor system comprising:

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

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

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

5. a pressure of the hydrocarbon-containing gas in the range of about -100 KPa to about 100,000 KPa; a first velocity of the hydrocarbon-containing gas in the hollow interior volume in the range of about 0.015 to about 20 fps; a second velocity of the hydrocarbon-containing gas in the quiet zone in the range of about 0.15 to about 20 fps; a third velocity of the hydrocarbon-containing gas in the fluidized bed in the range of about 0.015 to about 20 fps; a temperature of the hydrocarbon-containing gas in the fluidized bed in the range of about 550 to about 850°C; ９０ 5. The reactor system of claim 4, wherein the diameter ranges from about 0.1 to about 5 microns, the gas impermeable structure is an open cylinder, and the first and second ends of the gas impermeable structure are spaced apart from respective opposing surfaces of the reaction vessel.

6. 10. 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 allow catalytic cracking of hydrocarbons, and in a second mode, the gas-impermeable structure is in a different second position that is not hermetically sealed to allow removal of carbonaceous material from the reaction zone.

7. 10. The reactor system of claim 1, further comprising a vacuum pump positioned between a heat exchanger and a pressure swing absorption system to create a partial vacuum to induce flow of the reactant gas stream, the heat exchanger transferring heat from the reactant gas stream to the hydrocarbon-containing gas, and the vacuum pump in fluid communication with the outlet of the reaction vessel.

8. introducing a hydrocarbon-containing gas into an inlet of a reaction vessel, said reaction vessel comprising: a gas-impermeable structure including a sidewall having a hollow interior volume for receiving the hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas into the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end; one or more gas distributors positioned to direct the hydrocarbon-containing gas downwardly through the first end, the hollow interior volume, and the second end and upwardly through an annular volume between the gas-impermeable structure and the reaction vessel; and a bed of catalyst particulate matter positioned within the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials. including, steps, removing the reaction gas from an outlet gas conduit of the reactor; and removing a composite material comprising carbonaceous products and catalyst particles from an outlet of the reactor. A method comprising:

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

10. 9. The method of claim 8, wherein the gas impermeable structure comprises one of an elliptical cylinder and a cylinder, the sidewall being a surface of the one of the elliptical cylinder and the cylinder, and the one of the elliptical cylinder and the cylinder being centered substantially on a longitudinal axis of the reactor cylindrical sidewall.

11. the one or more gas distributors include one or more rotatable blades; removing substantially all entrained catalyst particulate matter from said reaction gas with a particulate separator; thereafter passing the reaction gas and the hydrocarbon-containing gas through a heat exchanger to transfer heat from the reaction gas to the hydrocarbon-containing gas to provide a cooled reaction gas and a preheated hydrocarbon-containing gas; passing the cooled reactant gas through a vacuum pump to create a vacuum that causes the reactant gas to flow through the particle separator; and passing the cooled reactor gas after passing through the vacuum pump through a pressure swing absorption system to separate and form a separated hydrocarbon-containing gas stream comprising at least a majority of the unreacted hydrocarbons in the cooled reactor gas from by-product hydrogen gas in the reaction gas, and separating and forming a separated hydrogen-containing gas stream comprising at least a majority of the by-product hydrogen gas. The method of claim 8 further comprising:

12. 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 a particulate catalyst at a gas velocity sufficient to entrain at least a majority of the particulate catalyst in the preheated mixed gas stream; and passing the preheated mixed gas stream containing entrained particulate catalyst through the inlet of the reactor vessel, wherein a velocity of the preheated mixed gas stream before passing through the inlet is greater than a velocity of the preheated mixed gas stream after passing through the inlet. The method of claim 11 further comprising:

13. a pressure of the hydrocarbon-containing gas in the range of about 100 to about 100,000 KPa; a first velocity of the hydrocarbon-containing gas in the hollow interior volume in the range of about 0.015 to about 20 fps; a second velocity of the hydrocarbon-containing gas upon discharge from the gas distributor in the range of about 0.015 to about 20 fps; a third velocity of the hydrocarbon-containing gas in the reaction zone in the range of about 0.015 to about 20 fps; a temperature of the hydrocarbon-containing gas in the reaction zone in the range of about 550 to about 850°C; ９０ 9. The method of claim 8, wherein the diameter ranges from about 0.1 to about 5 microns, the gas impermeable structure is a cone, and the ratio of the cone height (H) to the cone diameter (D) ranges from about 1:1 to about 6:

1.

14. the step of removing the composite material comprises:

10. The method of claim 8, comprising moving the gas-impermeable structure from a first location that is hermetically sealed to allow catalytic cracking of hydrocarbons to a different second location that is not hermetically sealed to allow removal of composite material from the reaction zone.

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

16. a reaction vessel including an inlet for a hydrocarbon-containing gas and an outlet for a reaction gas stream; a gas-impermeable structure including a continuous sidewall having a hollow interior volume for receiving the hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas into the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end, wherein the reaction vessel and the gas-impermeable structure have a common longitudinal axis; one or more rotatable blades having an axis of rotation aligned with the common longitudinal axis that direct the hydrocarbon-containing gas to flow downwardly through the first end, the hollow interior volume, and the second end, and upwardly through an annular volume between the gas-impermeable structure and the reaction vessel; a bed of catalyst particulate matter positioned within the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particulate matter to produce nanomaterials; and a quiet zone at the upper end of the reactor vessel between the first end of the gas impermeable structure and the upper surface of the reactor vessel, wherein the 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. a reactor system comprising:

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

18. the continuous sidewall is arcuate, the pressure of the hydrocarbon-containing gas is in the range of about -100 KPa to about 100,000 KPa, the first velocity of the hydrocarbon-containing gas in the hollow interior volume is in the range of about 0.015 to about 20 fps, the second velocity of the hydrocarbon-containing gas in the quiet zone is in the range of about 0.15 to about 20 fps, the third velocity of the hydrocarbon-containing gas in the fluidized bed is in the range of about 0.015 to about 20 fps, the temperature of the hydrocarbon-containing gas in the fluidized bed is in the range of about 550 to about 850°C, and the P ９０ 17. The reactor system of claim 16, wherein the diameter ranges from about 0.1 to about 5 microns, the gas impermeable structure is an open cylinder, and the first and second ends of the gas impermeable structure are spaced from respective opposing surfaces of the reaction vessel.

19. 17. 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 allow catalytic cracking of hydrocarbons, and in a second mode, the gas-impermeable structure is in a different second position that is not hermetically sealed to allow removal of carbonaceous material from the reaction zone.

20. 17. The reactor system of claim 16, further comprising a vacuum pump positioned between a heat exchanger and a pressure swing absorption system to create a partial vacuum to induce flow of the reactant gas stream, the heat exchanger transferring heat from the reactant gas stream to the hydrocarbon-containing gas, and the vacuum pump in fluid communication with the outlet of the reaction vessel.

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