Reactor and method for producing carbonaceous material

Abstract

In an embodiment of the present invention, a fluidized bed reactor for decomposing gaseous hydrocarbons into nanofibers and other carbonaceous materials and hydrogen comprises: an air impermeable structure comprising a continuous sidewall having a hollow interior volume, a gas-impermeable structure having a hollow interior volume receiving the hydrocarbon-containing gas passing through the first end, passing the hydrocarbon-containing gas through the hollow interior volume, and discharging the hydrocarbon-containing gas through the second end, the reaction vessel and the gas-impermeable structure having a common longitudinal axis; one or more gas distributors positioned to cause a hydrocarbon-containing gas to flow downward through the first end, the hollow interior volume, and the second end and upward through the annular volume between the gas impermeable structure and the reaction vessel; and a bed of catalyst particles positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce the nanomaterial.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. Provisional Application Serial No. 63 / 404,442, filed on September 7, 2022, and U.S. Provisional Application Serial No. 63 / 419,258, filed on October 25, 2022, both of which are entitled “Reactor and Process for Producing Carbonaceous Materials,” the entire disclosures of which are incorporated herein by reference. Technical Field

[0003] The present invention generally relates to reactors and methods for producing carbonaceous materials, and in particular to reactors and methods for producing carbon nanomaterials, particularly carbon nanofiber materials. Background Art

[0004] The thermal decomposition of methane into carbon and hydrogen (as shown in the following reaction equation (1)) is a moderately endothermic process, but its energy requirement per mole of carbon produced (75.6 kJ / mol) is significantly lower than the energy requirement required for the steam reforming process (about 190 kJ / mol). In addition, unlike steam reforming, the hydrogen produced by the thermal decomposition of methane can be produced in an oxygen-free environment and does not involve a water-gas shift reaction, so the reaction can produce a high-purity carbon and a carbon monoxide-free hydrogen stream.

[0005] CH4+75.6kJ / mol→C+2H2

[0006] Thermal decomposition of natural gas has long been used to produce carbon black, with the hydrogen produced being used as a supplemental fuel for the process. These processes are typically carried out in a semi-continuous manner using two reactors in series at high operating temperatures (typically about 1,400° C.), but those skilled in the art have attempted to lower these operating temperatures by 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 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) (the entire contents of which are incorporated herein by reference).

[0007] Compared with thermal decomposition, direct catalytic decomposition of methane has two major advantages: (i) the operating temperature can be significantly reduced, 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 high-value engineered carbon nanostructures can also be produced through the judicious use of catalysts, thereby increasing the commercial value of the process. Because natural gas is widely available in large quantities, it is technically feasible to catalytically decompose methane on an industrial scale to produce hydrogen and high-value carbon nanostructures. However, in order for this decomposition method to be of practical significance (i.e., commercial and economic significance), efficient catalysts that have been difficult to obtain so far are required. Such catalysts should exhibit high activity over long periods of time and continue to function in the presence of high concentrations of carbon deposits.

[0008] In addition, the catalytic decomposition of methane can be a fickle process due to the stringent requirements for metal particle size and the tendency of reaction conditions to adversely affect catalyst morphology. Previous work has shown that the highest solid carbon yields are obtained with catalysts having an average particle size of about 30 to 40 nm, but nickel catalyst particles can aggregate undesirably once in 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) (the entire contents of which are incorporated herein by reference). This particle sintering behavior results in reduced catalytic activity. Thus, while the concept of producing carbon and hydrogen by the catalytic decomposition of methane has attracted considerable interest and demonstrated technical feasibility, consistently obtaining the desired high-quality carbonaceous products has been elusive; many previous approaches in the art have failed to provide any degree of control over the type of carbon nanomaterial produced, and thus the carbonaceous products of these approaches must be purified by chemical and physical methods that are often difficult, expensive, and / or time consuming, and therefore preclude their use in commercial applications.

[0009] Furthermore, most catalytic cracking of methane and other solid carbon production reactors are of the fixed bed type, which has many disadvantages:

[0010] a) The endothermic reaction reduces the surface temperature of the catalyst, resulting in a slow to fast formation of carbon solids on the active face of the catalyst, which deactivates the catalyst. This ultimately results in very low yield conversion and makes the reactor configuration unsuitable for the production of solid carbon structures.

[0011] b) The fixed catalyst particles are covered by solid carbon nanomaterials, which reduces the driving force for the chemical adsorption of carbon molecules on the catalyst surface. Summary of the invention

[0012] These needs and other needs are addressed by various aspects, embodiments and configurations of the present invention.

[0013] In an embodiment of the present invention, the rotating medium fluidized bed reactor may include:

[0014] a. An inlet for hydrocarbon-containing gas;

[0015] b. a gas-impermeable structure comprising a continuous sidewall and a hollow interior volume for receiving a hydrocarbon-containing gas;

[0016] c. a plurality of gas distributors positioned about 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 to discharge the hydrocarbon-containing gas in a reaction zone located outside the gas-impermeable structure to generate a vortex fluid flow, the reaction zone including suspended catalyst particles to cause hydrocarbons in the hydrocarbon-containing gas to decompose to form carbonaceous materials; and

[0017] d. An outlet conduit for receiving the post-reaction gas, the outlet conduit having an inlet positioned substantially at the axis of the vortex fluid flow.

[0018] In an embodiment of the present invention, the method may include the following steps:

[0019] a. introducing a hydrocarbon-containing gas into an inlet of a rotating medium fluidized bed reactor, the fluidized bed reactor comprising:

[0020] b. a gas-impermeable structure comprising a continuous sidewall and a hollow interior volume for receiving a hydrocarbon-containing gas; and

[0021] c. a plurality of gas distributors positioned at 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 to discharge the hydrocarbon-containing gas in a reaction zone located outside the gas-impermeable structure to generate a vortex fluid flow, the reaction zone including suspended catalyst particles, so as to decompose hydrocarbons in the hydrocarbon-containing gas to form carbonaceous materials;

[0022] d. removing the post-reaction gas from the outlet conduit of the reactor; and

[0023] e. Removing the composite material including the carbonaceous products and catalyst particles from the reactor.

[0024] In an embodiment of the present invention, the rotating medium fluidized bed reactor may include:

[0025] a. An inlet for hydrocarbon-containing gas;

[0026] b. a gas-impermeable structure comprising a continuous sidewall and a hollow interior volume for receiving a hydrocarbon-containing gas;

[0027] c. a gas distributor positioned about 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 to discharge the hydrocarbon-containing gas in a reaction zone located outside the gas-impermeable structure to generate a vortex fluid flow, the reaction zone including suspended catalyst particles, to cause hydrocarbons in the hydrocarbon-containing gas to decompose to form carbonaceous materials; and

[0028] d. An outlet conduit for receiving the post-reaction gas, the outlet conduit having an inlet positioned substantially at the axis of the vortex fluid flow.

[0029] To assist in the vortex flow pattern and provide better catalyst particle suspension, each gas distributor may include an upwardly inclined ramp surface to direct the discharged hydrocarbon-containing gas upwardly along a flow path transverse to the central axis of the reactor and / or tangential to the continuous sidewall 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 clogging; and a channel interconnecting the inlet and outlet, the channel may have an arcuate central axis.

[0030] The reactor may include a gas curtain generator positioned at the inlet to the outlet conduit to discharge curtain gas in a flow direction transverse to the flow direction of the reacted gas to reduce the velocity of the reacted gas and substantially prevent entrained catalyst particles from entering the outlet conduit.

[0031] In an embodiment of the present invention, the reactor system may include:

[0032] a. a reaction vessel comprising an inlet for a hydrocarbon-containing gas and an outlet for a reacted gas stream;

[0033] b. a gas-impermeable structure comprising a continuous sidewall having a hollow interior volume, the hollow interior volume receiving a hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas through the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end, the reaction vessel and the gas-impermeable structure having a common longitudinal axis;

[0034] c. 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 the annular volume between the gas-impermeable structure and the reaction vessel; and

[0035] d. A bed of catalyst particles positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce nanomaterials.

[0036] In an embodiment of the present invention, the method may include the following steps:

[0037] a. introducing a hydrocarbon-containing gas into an inlet of a reaction vessel comprising:

[0038] i. an air-impermeable structure comprising a sidewall having a hollow interior volume, the hollow interior volume receiving a hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas through the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end;

[0039] ii. 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 the annular volume between the gas-impermeable structure and the reaction vessel; and

[0040] iii. a bed of catalyst particles positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce nanomaterials;

[0041] b. removing the post-reaction gas from the outlet conduit of the reactor; and

[0042] c. Removing the composite material including the carbonaceous product and catalyst particles from the outlet of the reactor.

[0043] In an embodiment of the present invention, the reactor system may include:

[0044] a. a reaction vessel comprising an inlet for a hydrocarbon-containing gas and an outlet for a reacted gas stream;

[0045] b. a gas-impermeable structure comprising a continuous sidewall having a hollow interior volume, the hollow interior volume receiving a hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas through the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end, the reaction vessel and the gas-impermeable structure having a common longitudinal axis;

[0046] c. one or more rotatable blades having axes of rotation along a common longitudinal axis to cause 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;

[0047] d. a bed of catalyst particles positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce nanomaterials; and

[0048] e. A quiet zone at the upper end of the reaction vessel between the first end of the air-impermeable structure and the opposite upper surface of the reaction 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 particles in the catalyst particle bed.

[0049] The airtight structure in any of the above embodiments can have a variety of three-dimensional shapes. For example, the airtight structure can include a polygonal prism, wherein the sidewall is the surface of the polygonal prism. The airtight structure can include an arcuate sidewall, such as the sidewall of a cone or a truncated cone prism.

[0050] Although any reaction may occur in the reactor system of the above-described embodiments, the reactor and method are generally used to catalytically decompose hydrocarbons in a hydrocarbon-containing gas into carbon nanofibers and hydrogen.

[0051] The gas distributor in any of the above embodiments may be fixed and include a plurality of gas distributors positioned substantially evenly around the perimeter of the gas impermeable structure.

[0052] The gas distributor in any of the above embodiments may include one or more gas injectors and / or one or more rotatable surfaces of a hydrocarbon-containing gas.

[0053] The gas distributor in any of the above embodiments may be rotatable and rotate about the longitudinal axis of the reactor and / or the gas-impermeable structure.

[0054] The continuous side wall in any of the above embodiments may be arcuate, and the gas impermeable structure may include an open cylinder centered on the longitudinal axis of the cylindrical side wall of the reactor.

[0055] The quiet zone in any of the above embodiments can be located at the upper end of the reaction vessel between the first end of the gas-impermeable structure and the opposite upper surface of the reaction vessel. The velocity of the hydrocarbon-containing gas in the quiet zone is generally less than the gas velocity required to entrain at least about 5% of the catalyst particles in the catalyst particle bed.

[0056] The operating conditions of the reactor system in any of the above embodiments depend on the specific implementation. The pressure of the hydrocarbon-containing gas is generally in the range of about -100 KPa to about 100,000 KPa; the first velocity of the hydrocarbon-containing gas in the hollow internal volume is generally in the range of about 0.015 to about 20 fps, the second velocity of the hydrocarbon-containing gas in the static zone is generally in the range of about 0.15 to about 20 fps, and the third velocity of the hydrocarbon-containing gas in the fluidized bed is generally in the range of about 0.015 to about 20 fps; the temperature of the hydrocarbon-containing gas in the fluidized bed is generally in the range of about 550° C. to about 850° C.; the P of the particulate catalyst particles is generally in the range of about 100 to about 150° C. 90 The size is typically in the range of about 0.1 to about 5 microns; the air-impermeable structure is typically an open elliptical or circular cylinder, wherein the first and second ends of the air-impermeable structure are spaced apart from respective opposing surfaces of the reaction vessel; and the ratio of the height (H) of the air-impermeable structure: the diameter (D) or width (W) of the air-impermeable structure is in the range of about 1:1 to about 6:1.

[0057] The reactor system in any of the above embodiments can use a dual-mode 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 materials from the reaction zone.

[0058] In any of the above embodiments, a vacuum pump can be positioned between the heat exchanger and the pressure swing adsorption system to generate a partial vacuum to cause the flow of the reacted gas stream. The heat exchanger transfers heat from the reacted gas stream to the hydrocarbon-containing gas, and the vacuum pump is in fluid communication with the outlet of the reaction vessel.

[0059] Depending on the specific configuration, the present invention can provide a variety of advantages. For example, eddy flow can provide higher slip velocity, which provides better heat and mass transfer. The quiet zone used to prevent entrained particles in the post-reaction gas can prevent clogging of the particle separator. The vacuum pump can maintain the operating pressure in the reactor within the safe operating requirements. The reactor system can produce nanofibers as bulk materials at low cost. The length of the nanofibers can be controlled by controlling the gas velocity in the reaction zone; that is, higher fluidizing gas velocities generally produce shorter nanofiber product lengths due to increased gas turbulence, while lower fluidizing gas velocities produce longer nanofiber product lengths. Depending on the embodiment, the method can be a continuous batch method or a continuous method.

[0060] These and other advantages will become apparent from the disclosure of the aspects, embodiments, and configurations contained herein.

[0061] As used herein, "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctions and disjunctions 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 of A, B, and C in the above expressions refers to elements such as X, Y, and Z or to categories of elements such as X1-X n 、Y1-Y m and Z1-Z o When the phrase is used, it is intended to refer to individual elements selected from X, Y, and Z, combinations of elements selected from the same category (e.g., X1 and X2), and combinations of elements selected from two or more categories (e.g., Y1 and Z o ).

[0062] It should be noted that the term "an" entity refers to one or more of that entity. Therefore, the terms "one", "one or more", and "at least one" can be used interchangeably herein. It should also be noted that the terms "comprising", "including", and "having" can be used interchangeably.

[0063] As used herein, the term "means" should be interpreted as broadly as possible in accordance with 35 U.S.C. Section 112(f) and / or Section 112(6). Therefore, claims including the term "means" should cover all structures, materials, or acts set forth herein and all their equivalents. In addition, structures, materials, or acts and their equivalents should include all those described in the Summary of the Invention, the Figures, the Detailed Description, the Abstract, and the claims themselves.

[0064] Unless otherwise indicated, all component or composition levels refer to the active portion of that component or composition, and are exclusive of impurities, such as residual solvents or by-products, which may be present in commercial sources of such components or compositions.

[0065] All percentages and ratios are calculated by weight of the total composition, unless otherwise specified.

[0066] It should be understood that each maximum numerical limit given throughout the present invention is considered to include each and each lower numerical limit as an alternative, as if these lower numerical limits are clearly written in this article. Each minimum numerical limit given throughout the present invention is considered to include each and each higher numerical limit as an alternative, as if these higher numerical limits are clearly written in this article. Each numerical range given throughout the present invention is considered to include each and each narrower numerical range falling within such a wider numerical range, as if such a narrower numerical range is clearly written in this article. For example, the phrase about 2 to about 4 includes integers (whole number / integer) within the range of about 2 to about 3, about 3 to about 4, and each possible range based on real numbers (e.g., irrational numbers and / or rational numbers), such as about 2.1 to about 4.9, about 2.1 to about 3.4, etc.

[0067] The above is a brief summary of the invention to provide an understanding of some aspects of the invention. This summary is neither a broad overview nor an exhaustive overview of the invention and its various aspects, embodiments, and configurations. Its purpose is neither to determine the key or important elements of the invention nor to limit the scope of the invention, but to present the selected concepts of the invention in a simplified form as an introduction to the more detailed description below. As will be understood, other aspects, embodiments, and configurations of the invention may utilize one or more features described above or described in detail below, alone or in combination. Also, although the invention is presented according to exemplary embodiments, it should be understood that various aspects of the invention may be claimed separately. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present invention. These drawings, together with the description, explain the principles of the present invention. The accompanying drawings simply illustrate preferred and optional examples of how to make and use the present invention, and should not be construed as limiting the present invention to only the examples shown and described. Further features and advantages will become clear through the following more detailed description of various aspects, embodiments and configurations of the present invention, as shown by the accompanying drawings referenced below.

[0069] Figure 1A is a block diagram of a reactor system according to an embodiment of the present invention;

[0070] Figure 1B is a block diagram of a reactor system according to an embodiment of the present invention;

[0071] Figure 2A is a schematic diagram of the embodiment of Figure 1;

[0072] Figure 2B is a front view of a reactor system according to the embodiment of FIG. 1 ;

[0073] Figure 3 yes Figure 2B A rear perspective view of a reactor system (wherein the side wall of the reactor housing is omitted);

[0074] Figure 4 yes Figure 2B A top perspective view of a reactor system (wherein the side wall of the reactor shell is omitted);

[0075] Figure 5 yes Figure 2B A front cross-sectional view of a reactor system;

[0076] Fig. 6A yes Figure 2B a disassembled view of a portion of a reactor system;

[0077] Figure 6B yes Fig. 6A An assembled view of a portion of a reactor system shown in ;

[0078] Figure 7 yes Figure 2B a cross-sectional view of a portion of a reactor system;

[0079] Figure 8 yes Figure 2B A side view of a gas distribution device of a reactor system;

[0080] Fig. 9 yes Figure 7 an exploded view of a portion of the reactor system shown in;

[0081] Fig.10 yes Figure 7 a perspective exploded view of a portion of the reactor system shown in;

[0082] Fig.11 yes Figure 2B a cross-sectional view of a portion of a reactor system;

[0083] Fig.12 yes Figure 2B A perspective cutaway view of a portion of a reactor system;

[0084] Fig.13 yes Figure 2B A plan view of a gas distribution device of a reactor system;

[0085] Fig.14 yes Figure 2B an exploded view of a portion of a gas distribution device of a reactor system;

[0086] Fig.15 yes Figure 2B an exploded view of a portion of a gas distribution device of a reactor system;

[0087] Fig.17 yes Figure 2B A bottom view of a gas distribution device and a reactor cone of a reactor system;

[0088] Fig.18 yes Figure 2B A side view of a gas distribution device and a portion of a reactor cone of a reactor system;

[0089] Fig.19 yes Fig.18 A partial side cross-sectional view of a portion of a gas distribution device and a reactor cone;

[0090] Fig. 20 yes Fig.18 A side cross-sectional view of a portion of a gas distribution device and a reactor cone;

[0091] Fig.21 yes Fig.18 Another side cross-sectional view of a portion of the gas distribution device and the reactor cone;

[0092] Fig. 22 yes Figure 2B A side view of a gas curtain generator of a reactor system;

[0093] Fig.23 yes Fig. 22 Bottom view of the air curtain generator;

[0094] Fig.24 yes Fig. 22 A top view of an air curtain generator;

[0095] Fig.25 yes Fig. 22 A top cross-sectional view of an air curtain generator;

[0096] Fig.26 yes Fig. 22 A bottom cross-sectional view of an air curtain generator;

[0097] Fig. 27 Shows Figure 2B a first spatial position of a reactor cone arrangement of a reactor system that enables product and catalyst removal;

[0098] Fig.28 Shows Figure 2B a second spatial position of the reactor cone arrangement of the reactor system, which enables catalytic production of the product;

[0099] Fig.29A is a block diagram of a reactor system according to an embodiment of the present invention;

[0100] Fig.29B is a block diagram of a reactor system according to an embodiment of the present invention;

[0101] Fig. 30A is a cross-sectional view of a reactor along a longitudinal bisector plane according to an embodiment of the present invention;

[0102] Fig. 30B is a cross-sectional view of a reactor along a longitudinal bisector plane according to an embodiment of the present invention;

[0103] Fig.31A is a block diagram of a reactor system according to an embodiment of the present invention;

[0104] Fig.31B is a block diagram of a reactor system according to an embodiment of the present invention;

[0105] Fig.32is a block diagram of a reactor system according to an embodiment of the present invention; and

[0106] Fig.33 According to an embodiment of the present invention, Fig. 30A and Fig. 30B A cross-sectional view of the reactor in a transverse bisector plane. DETAILED DESCRIPTION

[0107] In an embodiment of the present invention, a fixed chamber rotating medium fluidized bed reactor for decomposing gaseous hydrocarbons into nanofibers and other carbonaceous materials and hydrogen is described. The reactor can have a fixed or rotating gas distributor, which includes inclined grooves and / or precise orifices to produce a slip velocity vortex of reactant gas flow around an airtight cone. "Slip velocity vortex" refers to a vortex flow pattern including hydrocarbon gas and particulate catalyst, which provides a slip velocity, or the difference between the velocity of the particulate catalyst and the gas phase velocity. In fluid dynamics, a vortex is an area in which the flow in a fluid rotates around an axis, which can be straight or curved or curved. Although the embodiments discussed below are with reference to a fixed gas distribution assembly, it should be understood that the gas distribution assembly can be configured to rotate around the longitudinal axis of a post-reaction gas exhaust conduit centrally positioned in the reactor.

[0108] In an embodiment of the invention, a fluidized bed reactor for decomposing gaseous hydrocarbons into nanofibers and other carbonaceous materials and hydrogen includes a fixed or movable gas-impermeable and open-ended baffle to position a fluidized bed in an annular space between the baffle and the reactor wall while leaving the internal volume of the baffle substantially free of catalyst particles. Gas flow through the open baffle ends, downward through the internal volume of the baffle, and upward through the annular space to fluidize the bed is provided by rotation of one or more blades, the rotation axis of the blades being substantially aligned with the common longitudinal axis of the baffle and the reactor.

[0109] It should also be understood that in the above embodiments, innovations can be implemented by pumping the reactant gases with a blower before the reactor or by placing a vacuum pump on the reactor outlet, both techniques achieving the same reactant gas delivery requirements.

[0110] refer to Figure 1A , shows an embodiment of a hydrocarbon gas decomposition reactor system 100 according to the present invention. The reactor system 100 includes a reactor 101, discussed in more detail below, which is in fluid communication with a particulate separator 122 and a heat exchanger (HX) 106 via a conduit 105. Fresh hydrocarbon feed or hydrocarbon gas 110 is preheated to a temperature suitable for separation in the HX 106. The hydrocarbon gas decomposition reaction selectively produces a first intermediate carbonaceous product 125 and a second intermediate carbonaceous product 114 from a particulate catalyst 123 and the hydrocarbon gas 110.

[0111] Fresh hydrocarbon gas 110 is first preheated by waste heat from product or reacted gas 190 in 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 new and recovered methane, where the preheated gas 110A is heated together with hydrogen 111A that is re-delivered from a portion of a recovered hydrogen stream 111 from a pressure swing adsorption (PSA). PSA is a gas separation device well known in the industry that separates gaseous substances from a gas mixture under pressure based on the molecular properties of the substances and their affinity for adsorbent materials. By controlling pressure and temperature, a specific dew point can be adjusted to slow down the movement of one gas from other gases. Specifically, in the present invention, the product gas 111 from the reactor 101 will be a mixture of hydrogen and unreacted methane. When recovering methane from a PSA, a "purge" gas is typically used to remove methane from the PSA pressure vessel. Hydrogen (H2) is usually used as a purge gas and becomes part of the "recovered methane" gas. The PSA will transport methane to the equalization tank 104, and the methane recovered in the equalization tank 104 will be mixed with fresh methane. The mixed gas is preheated to the reaction temperature by a preheater 124 and fed to the reactor as a preheated mixed gas stream 126. The hydrocarbon gas can be any gaseous hydrocarbon, usually a shorter chain hydrocarbon gas, such as a gas from the alkane family (e.g., methane, ethane, propane, butane, pentane and hexane), and more usually methane. The hydrocarbon gas can also be any gas from the olefin family (carbon-carbon double bond), the alkyne family (carbon-carbon triple bond) or the aromatic family. In one embodiment, the hydrocarbon gas includes at least about 50 mol %, more usually at least about 75 mol %, and even more usually at least about 90 mol % of methane, and the balance is nitrogen, hydrogen or carbon dioxide gas. To avoid oxidation of carbonaceous material formed 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 percent molecular oxygen and other oxidants.

[0112] The particle 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 alkali metals, transition metals and alkaline earth metals, such as the catalyst disclosed in U.S. application 63 / 225,733 entitled "Catalyst for the Generation of Graphitic Nanofibers and CO-Free Hydrogen" filed concurrently with the present invention. The particle catalyst 123 generally has a P in the range of about 0.10 to about 5.0 microns. 90 size.

[0113] The particle separator 122 can be any device that can separate gas from entrained particles. In one embodiment, the particle separator 122 is a cyclone separator, which 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 produces a spiral vortex. The lighter components in this gas have less inertia, so they are more easily affected by the vortex and move upward. In contrast, the larger components of the particulate matter have greater inertia and are less susceptible to the vortex. In one embodiment, the particle separator 122 is a centrifuge. Like a cyclone separator, a centrifuge rotates objects around a central axis. This rotation exerts greater force on dense materials than on less dense materials, separating objects based on their density.

[0114] In some embodiments, the particulate separator is a housing having a cartridge filter element 191 that passes the post-reaction gas as a filtrate but retains entrained particles as a retentate, with the preheated hydrogen 109A used to cause automatic backwashing to remove the retentate from the cartridge's filter media. The filter media can be periodically backwashed during the production of carbonaceous material by opening and closing valve 108A with valve 108B, temporarily pausing the fluid connection between reactor 101 and heat exchanger 106. The first intermediate carbonaceous product 125 (filtered solids) from the backwash is directed back to the reactor chamber.

[0115] The mixed hydrocarbon gas 113 and hydrogen 111A are preheated by the preheater 124 and fed to the reactor 101, where it interacts with the particulate catalyst 123 to form the first intermediate carbonaceous product 125 or the second intermediate carbonaceous product 114. The hydrocarbon gas is usually heated to a temperature in the range of about 550°C to about 850°C and is input at a pressure in the range of about -100KPa (when a vacuum pump is used to deliver the reactant gas) to about 100KPa (when a blower is used to deliver the reactant gas) and a gas velocity in the range of about 0.015 to about 20fps. The mixed hydrocarbon gas 113 is substantially diffused or distributed in the reactor, and the particulate catalyst is suspended or fluidized by forming a vortex flow pattern. The 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, the material falls off under the force of the fluidizing gas, is suspended by the fluidizing gas, and when the fluidizing gas stops, the material falls to the bottom of the reactor as a second intermediate carbonaceous product. In one embodiment, the method is operated under conditions that substantially minimize the shedding of the material and cause the particulate catalyst 123 and attached carbonaceous material to be 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. Backwashing on the cartridge filter element 1913 using hydrogen 109A returns the first intermediate product 125 to the reactor 101.

[0116] In another embodiment, the cartridge filter element 191 ( Figure 1B ) is suspended inside the reactor, and a simple backwash is performed to allow the first intermediate carbonaceous product to fall back into the reactor 101. In this embodiment, an external particle separator 122 is generally not used.

[0117] Reference again Figure 2A In order to substantially minimize the volume of particulates exiting the reactor and entering the particulate separator 122, a quiet zone mechanism is provided for preventing the particulate catalyst 123 and the intermediate carbonaceous products from exiting the reactor 101. Via the gas flow conduit 112, a curtain gas 158 (e.g., a reducing gas such as hydrogen or a noble gas) forms a gas curtain or reverse gas flow within the conduit 112 to cause the gas velocity within the quiet zone 201 to be reduced. As discussed below, the reduced gas velocity is lower than the gas velocity required to entrain the particulate catalyst 123 and / or the intermediate carbonaceous products, thereby causing the particulates 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 no more than about 75% of the exit velocity, and even more typically no more than about 50% of the exit velocity.

[0118] Reference now Figure 2A , a more detailed embodiment of the reactor system 200 is shown.

[0119] An input gas compressor or blower 109 feeds preheated hydrocarbon gas 110 into the reactor through an input gas flow conduit 120, with a gas velocity typically in the range of about 0.015 to about 20 fps. A gas stream 126 is forced through a gas distributor assembly 204 at a first velocity (typically in the range of about 0.015 to about 20 fps), which includes a cone 212 and a gas distributor system 216, as indicated by gas flow arrows 220 (which are typically substantially tangential to the circular surface of the cone 212), to create a vortex 208 from the inflowing gas rotating around the cone 212 at a lower second velocity (typically in the range of about 0.015 to about 20 fps). The reactor cone 212 provides a conical, gas-impermeable structure for the gas vortex 208 to rotate around.

[0120] The tapered continuous sidewall of the cone 212 provides a different flow cross-sectional area relative to the area between the cone sidewall and the inner surface of the reactor 101. The different flow cross-sectional areas that gradually increase from the base of the cone to the top of the cone can provide different velocity zones and different glide speeds. In many applications, the low velocity zone is close to the base of the cone (and is generally in the range of about 10% to about 15% of the height H of the cone 212), while the high velocity zone is close to the top of the cone (and is generally above about 40% of the cone height H), and the medium velocity zone is located between them (which is generally in the range of about 15% to about 40% of the cone height H). The glide speed in the low velocity zone is generally less than the glide speed in the medium velocity zone, and the glide speed in the high velocity zone is generally greater than the glide speed in the medium velocity zone and the low velocity zone. Although the continuous tapered sidewall of the cone 212 is shown in the drawings, it should be understood that the sidewall can be discontinuously tapered or stepped to provide similar velocity zones.

[0121] The particulate catalyst 123 is introduced into the reactor 101 prior to startup, either by the venturi effect created by the reactant gas flow and / or during operation through the feed chamber 3228 (see Fig.32) is fed, and the vortex 208 generated by the gas distributor 216 keeps the particulate catalyst 125 particles (not shown) suspended in the reaction zone with turbulent flow around the periphery of the cone 212. The gas stream 126 reacts with the particulate catalyst 123 particles suspended in the vortex 208, and the particulate catalyst 123 particles begin to grow carbonaceous materials, such as graphite nanofibers, which increases the weight of the catalyst particles. The curtain gas 158 is fed into the reactor 101 in the opposite flow direction of the gas stream 126 via the top-down curtain gas flow conduit 224 and the gas curtain generator 226 positioned in the gas flow conduit 112 to form a gas curtain 228 having a third gas flow velocity less than the first gas flow velocity and the second gas flow velocity. The downward flow of the curtain gas 158 effectively forms a curtain with a low gas velocity (the ratio of curtain:feed flow rate is typically in the range of about 1:3 to about 1:6) to prevent the particulate catalyst particles 123 from rising above the turbulence or reaction zone formed by the vortex 208. The gaseous mixture 210 of unreacted hydrocarbon gas and gaseous byproducts (e.g., hydrogen) and curtain gas exits the vortex 208 as a particulate-free gas via the recycle flow conduit 112.

[0122] The reactor discharge silo 232 is fluidly connected to the reactor 101. Intermittently, when a sufficient amount of carbonaceous material falls off the particulate catalyst 140 within the turbulent gas vortex 208, the input shaft 236 assists the sliding of the gas distributor assembly 204 by following the discharge guide member 240, and the combination of these functions will tilt the gas distributor assembly 204, allowing the carbonaceous material to fall into the silo 232 which is hermetically sealed to prevent oxygen from contacting the carbonaceous material.

[0123] 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 air lock 256 and a jacketed cooling auger 260 driven by a motor 264.

[0124] refer to Figure 2B and Figures 3 to 5 , showing a specific embodiment of a reactor system 200. The cylindrical reactor 101, the particle separator 122, and the compressor or blower 109 are shown as being in fluid communication with each other via the circulation flow conduits 112 and 116, the input gas flow conduit 120, and the circulation flow conduit 128. Figure 5, the circulating flow conduit 128 and the circulating flow conduit 112 each extend into the interior of the reactor, as shown in the first circulating conduit segment 500 and the second circulating conduit segment 504, respectively. The first inlet 508 of the first circulating conduit segment 500 extends into the interior of the reactor a shorter distance than the second inlet 512 of the second circulating conduit segment 504; that is, the first inlet 508 is positioned above the second inlet 512 to prevent the particulate catalyst particles 140 from being removed from the reaction zone prematurely. The second inlet 512 is positioned spatially close to the top 516 of the cone 212, and in some embodiments, is positioned within the second inlet 512 and the second circulating conduit segment. The cone 212, the circulating flow conduit 112, and the second inlet 512 are centered on the longitudinal axis 272 of the reactor 101.

[0125] Figure 2B and Figures 3 to 5 The embodiment includes a second reactor discharge bin 520 positioned below the particle separator 122 to receive the first intermediate carbonaceous product 125. The use of the dual reactor discharge bins 232 and 520 enables lighter composite particles to be removed by blowing the composite particles into the first inlet 508 using an air flow velocity (higher than the second air flow velocity) to be aggregated in the second reactor discharge bin 520 as the first intermediate carbonaceous product 125, while heavier composite particles are removed by spatial movement of the gas distributor assembly 204, the lighter composite particles including the particulate catalyst 140 and a lighter amount of carbonaceous material (e.g., a shorter carbon nanofiber length), and the heavier composite particles including the particulate catalyst 140 and a heavier weight of carbonaceous material (e.g., a longer carbon nanofiber length).

[0126] Will refer to Fig. 6A , Figure 6B , Figures 9 and 10 , Fig.12 as well as Figure 27 to Figure 28 , the discharge of the second intermediate carbonaceous product 125 into the reactor discharge silo 232 is described. As can be seen from the figure, the gas distributor assembly 204 is fastened to the base of the reactor 101 and the interior 1004 of the gas distribution system 216 via a flange assembly including a flange 600 and interconnected conduit segments 604 by a plurality of fasteners 606. The inlet of the conduit segment 604 is connected to the outlet of the elbow 608, and the inlet of the elbow 608 is movably engaged with the outlet of the input gas flow conduit 120. In order to maintain a gas-tight seal between the elbow 608 and the input gas flow conduit 120, the inlet of the elbow 608 includes a sealing gasket assembly 1000.

[0127] To discharge the second intermediate carbonaceous product 114 into the reactor discharge silo 232 , the reactor assembly 100 is operated in a first mode and a second mode.

[0128] exist Fig.28 In the first mode shown, the gas distributor assembly 204 including the cone 212 and the gas distributor 216 engages with the reactor 101 through a gas-tight seal, and the gasket assembly 1000 at the inlet of the elbow 608 engages with the outlet of the input gas flow conduit 120 and forms a gas-tight seal. The gas distributor assembly 204 and the conduit section 604 are in a first spatial position relative to the length of the exhaust guide member 240. In this configuration, the reactor 101 is fluidized with the hydrocarbon gas 110 so that graphite or carbon nanofibers are formed on the particulate catalyst 123.

[0129] exist Fig. 27 In the second mode shown, the gas distributor assembly 204 is disengaged from the reactor 101 (and no longer forms a gas-tight seal), and the gasket assembly 1000 at the inlet of the elbow 608 is disengaged from the outlet of the input gas flow conduit 120 (and no longer forms a gas-tight seal). 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 member 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 silo 232.

[0130] Any shifting mechanism can be used to selectively place the reactor assembly in the first mode or the second mode. For example, the input shaft 236 can engage a cam, which rotates to cause the input shaft to move up and down. In another example, the input shaft is pneumatically or hydraulically shifted.

[0131] Although the discharge guide member 240 is shown as a guide rail that movably engages a guide member 2700 (eg, a protruding pin or wheel), any guide member or linkage mechanism may be used, such as a linear slide mechanism including a ball bearing that moves along an axis.

[0132] refer to Figures 7 and 8 as well as Figures 13 to 21 , the gas distributor assembly 204 will be described. The gas distributor assembly 204 includes a plurality of gas injectors 1416 positioned at substantially evenly spaced locations around the circumference of the interior 1004 of the gas distributor assembly 204. The holes 1300 positioned at substantially evenly spaced locations around the inlet 704 are aligned with the holes in the flange 600 and are configured to receive the fasteners 606.

[0133] The interior volume 700 of the cone 212 is at least substantially hollow, and the cone sidewalls are impermeable to gas flow to act as a manifold for hydrocarbon gas entering via the inlet 704, so that the hollow interior substantially equalizes the pressure of the incoming hydrocarbon gas before the gas flows through the plurality of inlet orifices 708, flows through the corresponding internal channels 1400, and flows outwardly through the corresponding output orifices 1404 in the substantially vertical surface 1406 into the reactor interior volume. In order to provide smoother gas flow and reduced gas pressure loss, the channels 1400 are typically curved (e.g., arcuate or in some cases rounded) and not at sharp angles. The outflowing gas is guided by the ramp 1408 along a flow path substantially parallel to the slope of the ramp (which is typically about 1 to about 75 degrees relative to the horizontal plane, more typically about 1 to about 45 degrees) and enters the reactor interior. The rounded edge 1412 of each of the plurality of gas injectors 1416 provides a smooth gas outlet into the reactor interior.

[0134] Typically, the inlet orifice 708 and the output orifice 1404 of each gas injector 1416 and all gas injectors 1416 and each intermediate passage 1400 have substantially the same diameter. The diameter is selected to provide an output gas velocity of at least the terminal velocity of the particulate catalyst particles to maintain entrainment of the particles and prevent accumulation of particles in the substantially flat surface 1416 at the output orifice 1404 and gas injector clogging. Typically, the output gas velocity is in the range of about 0.5 to about 20 fps.

[0135] The cone angle θ2000 ( Fig. 20 ) determines the velocity of the gas flow in the reaction zone and the size of the carbonaceous material (e.g., graphite nanofibers) produced. For example, to prepare longer graphite nanofibers, the angle θ is reduced to produce a lower gas velocity in the reaction zone, while to prepare shorter graphite nanofibers, the angle θ is increased to produce a higher 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 θ2000 is in the range of about 1 to about 45 degrees, and the ratio of the cone height (H) to the cone diameter (D) ( Figure 8 ) is in the range of about 1:1 to about 6:1.

[0136] Reference Fig.11 as well as Figure 22 to Figure 26, an air curtain generator 1100 for releasing a curtain of air will be described. The air curtain generator 1100 is in fluid communication with a curtain air supply conduit 1104, which is connected to a fitting 1108 of the generator 1100 and forms an airtight seal therewith. The curtain air flows through the inlet 2500, through the passage 2504 and into the annular space 2508 for release through the annular ring 1112 to form an air curtain. Fig. 22 As shown in FIG. 5 , the diameter of the generator 1100 is gradually reduced from a first larger diameter inlet 2200 that joins the catheter segment 504 to a second diameter outlet 2204 having a smaller diameter. This gradual reduction is accomplished using an intermediate section 2208 that gradually reduces in diameter from the first diameter to the second diameter.

[0137] exist FIG. 29A to FIG. 29B as well as FIG. 30A to FIG. 30B In another embodiment of the reactor design shown, turbulence 208 is generated by internal circulation of the feed gas. Unlike the reactor design discussed above in which turbulence 208 is in a flow path that is substantially spiral around the circumference of the cone 212 (e.g., in a flow path that is transverse to the longitudinal axis of the reactor), due to the open upper and lower ends of the baffle 301, the turbulence 208 is in a substantially vertical plane (e.g., in a plane that is substantially parallel to the longitudinal axis of the reactor). Although the baffle 301 and the reactor 300 can be any desired curved and / or angled and / or curved transverse or longitudinal cross-sectional shape, the shapes of the baffle 301 and the reactor 300 should be the same. Common cross-sectional shapes include ellipses or circular cylinders. For example, as Fig.33 As shown, a baffle 301 that is cylindrical in transverse cross-section is used in a reactor that is also cylindrical in 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 perimeter of the baffle. Fig.33As shown, the cylindrical baffle 301 and the reactor vessel share a common longitudinal axis. When the reactor is a closed vessel, the baffle 301 has an open upper side end 308 and a lower side end 312 to allow gas to flow outwardly upward (as shown by flow arrows 314) and inwardly downward relative to the baffle (airtight) side wall 316 as shown in the figure and around the upper side end 308 and the lower side end 312 on the baffle. The reactor 300 includes a fan assembly, which includes a motor 303 operably connected to one or more fan blades 320 via a drive shaft 324 so that the gas circulates in the reactor 300 in the manner described. The gas is continuously circulated in the reactor by rotating one or more fan blades 320 in a counterclockwise direction, so as to fluidize the bed of particulate catalyst particles in the reaction zone 328 between the side wall 316 and the reactor 300 wall. Typically, the open lower side end of the baffle and the baffle internal volume 330 are substantially free of catalyst particles. All external arrangements remain the same. Although reactor 300 is described with specific reference to a fan assembly, other methods may be used to induce fluidizing gas flow, including gas injectors positioned at reactor upper end 308 or at the reactor lower end in the reaction zone outside sidewall 316 as described above.

[0138] Quiet zone 390 is not formed using a gas curtain like quiet zone 201. Instead, it is formed by carefully controlling the gas velocity in reactor 300 in combination with the turbulent flow 208 morphology (which forms vortices that prevent particles from being entrained by the gas leaving the reactor). As discussed below, 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 in reactor 300. As will be appreciated, the gas flow is typically maintained at a velocity of no more than about 90%, more typically no more than about 80%, of the velocity required to entrain unreacted catalyst particles. As carbon nanomaterials form on the catalyst particles, the particles become heavier and require higher velocities for entrainment. The highest level of particle entrainment typically occurs when fresh catalyst particles are introduced into reactor 300. The size of the quiet zone typically depends on the vertical gas velocity, the size and weight / density of the particles, the reactor diameter, etc.

[0139] exist FIG. 31A to FIG. 31BIn another embodiment of the reactor design shown, a product discharge stage (e.g., a carbon discharge stage) can be deployed to remove composite materials including carbonaceous products and / or catalyst particles (e.g., the first intermediate carbonaceous product 125 or the second intermediate carbonaceous product 114) from the reactor. The product discharge stage can be achieved by causing the flow of the fan assembly (e.g., reversing the direction of the fan blades 320) to be generally in a clockwise direction and reversing the reactor flow pattern. In addition, the inlets 103, 105, 326, or a combination thereof can be sealed. In one embodiment, inlets 103 and 105 can be sealed, while inlet 326 can remain open during the product discharge stage. In some embodiments, inlets 103 and 105 can be opened during the catalyst feed cycle and can remain closed at all other times, such as during the product discharge stage. In reference to Fig.31A In one embodiment, inlet 326 and valve 108A may be closed for the product discharge phase. Fig.31B In one embodiment, valve 108A may be closed and inlet 326 may remain open during the product discharge phase.

[0140] Thus, when producing carbonaceous products, one or more of the inlets (e.g., inlets 103, 105, and 326) and / or one or more valves (e.g., valve 108A) can be closed (e.g., sealed), such as in a batch reactor design, and the flow of the fan assembly can be reversed. During the product discharge phase and in response to the reversal of the fan direction, the flow of the return gas can flow outwardly downwardly and inwardly (typically hydrogen) upwardly through the center of the filter housing (e.g., FIG. 31A to FIG. 31B As shown). Thus, the carbonaceous product can flow downward. The carbonaceous product can then leave the reactor via a valve, door, etc. opened at the bottom of the reactor. In some embodiments, reference Fig.31A and Fig.31B , line 322 may be opened (e.g., may be cyclically opened) for the product discharge phase, e.g., to allow the product to be removed from the reactor. The carbonaceous product may be collected in a reactor discharge silo (117, 118, or both), e.g., as described in reference Figure 2A Depicted reactor discharge silo 232. In some embodiments, the reactor discharge silo may include or lead to a cooling loop.

[0141] Fig.29A , Fig. 30A and Fig.31A The reactor design may have an external filter reactor configuration as described above, while Fig.29B , Fig. 30B and Fig.31B The reactor design can have an internal filtering reactor configuration as also described above.

[0142] Although Fig.29A , Fig. 30A and Fig.31A Reactor designs can use baffles with open upper and / or lower ends spaced apart from the relative inner walls of the reactor vessel as shown in the figure, it being understood that the configuration of the open ends can also be achieved by other baffle configurations. For example, the permeable upper or lower portions of the baffles can also be positioned adjacent to the impermeable center portion of the baffle. The permeability can be produced by a perforated or ventilated surface having one or more openings, slits, orifices, ports or other holes to allow air flow through. In some configurations, the opening size is less than the average, mean, median or P of the catalyst particles before the nanomaterial is substantially formed. 50 or P 25 The baffle may be sized (depending on the reactor configuration) to maintain the interior of the baffle substantially free of catalyst particles. The gas permeable upper or lower portion may be connected to the upper or lower reactor vessel wall or spaced apart from the wall. The gas permeable upper or lower portion may be positioned only in part or all of the upper or lower end of the baffle.

[0143] Fig.32 3200. The reactor system 3200 includes a reactor 3204 (which can be any of the reactor configurations discussed above) that is fluidly connected to a particle separator 122 and a multi-stage heat exchanger (HX) 106 via a conduit 3208. A fresh hydrocarbon feed or hydrocarbon gas 110 (which is typically mainly methane and / or other short-chain hydrocarbons) is preheated in the HX 106 to a temperature suitable for separation. The hydrocarbon gas decomposition reaction selectively produces a first intermediate carbonaceous product 125 and a second intermediate carbonaceous product 114 from the particle catalyst 123 and the hydrocarbon gas 110.

[0144] The hydrocarbon gas 110 is first preheated in the HX 106 by waste heat from the product or reacted gas 190 (which is a mixture of unreacted methane and / or other short-chain hydrocarbons and byproduct hydrogen), forming preheated hydrocarbon gas 3208 and cooled reacted gas 3212. The cooled reacted gas 3212 is optionally passed through a vacuum pump 3216, which creates a partial vacuum and provides a driving force to cause 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 lower temperature gas stream. The vacuum pump 3216 can be any type of vacuum pump, such as a positive displacement, momentum transfer, and capture vacuum pump. The cooled reacted gas 3212 then flows into a compressor 3220 to pressurize the gas (which is a mixture of mainly unreacted methane and / or other short-chain hydrocarbons and by-product hydrogen) so that it can be separated into a recovered hydrogen-containing stream 111 and a separated hydrocarbon-containing stream 115 by PSA 107. PSA 107 is fluidly connected to a cooler 3224 via a coolant to maintain PSA 107 within a desired operating temperature range.

[0145] 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 vent 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 includes about 70 to about 100 mole % methane and / or other short chain hydrocarbons and about 30 to about 0 mole % hydrogen (H2).

[0146] The mixed gas is preheated to reaction temperature by preheater 124 and combined in line with particulate catalyst 123 included in particulate catalyst container 3228 in fluid communication with 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, for example, 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 most of the catalyst particles in the gas stream. Typically, the gas stream velocity is in the range of about 0.1 fps to about 1.0 fps, and the size of at least most of the catalyst particles is in the range of about 0.5 microns to 5 microns.

[0147] Blower 109 is optionally positioned immediately upstream or downstream of the catalyst introduction location (as shown) to pressurize the gas before introduction into the reactor. Typically, reactor system 3200 will use either vacuum pump 3216 or blower 109 depending on the application. The advantage of a vacuum pump over a blower 109 is that in the event of a plugged or partially blocked separator 122, the risk of the vacuum pump increasing the operating pressure of the reactor to above the desired operating pressure can be lower.

[0148] 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 intermediate carbonaceous product 125 and the second intermediate carbonaceous product 114 and the product or reacted gas 190. The preheated gas stream 3232 is typically heated to a temperature in the range of 550°C to about 850°C and is input at a pressure in the range of about -100 KPa (when the reactant gas is delivered using the vacuum pump 3126) to about 100 KPa (when the reactant gas is delivered using the blower 109) and a gas velocity in the range of about 0.015 to about 20 fps. The mixed hydrocarbon gas 113 is substantially diffused or distributed in the reactor and the particulate catalyst is suspended or fluidized by the flowing turbulent gas. The carbonaceous material (usually carbon nanomaterial, more typically carbon nanofiber material) grows on the suspended particulate catalyst 123, and when the material reaches a threshold size, the material falls off under the force of the fluidizing gas, is suspended by the fluidizing gas, and when the fluidizing gas stops, the material falls to the bottom of the reactor as a second intermediate carbonaceous product. In one embodiment, the method is operated under conditions that substantially minimize the shedding of the material and cause the particulate catalyst 123 and the attached carbonaceous material to be removed from the reactor 3204 by the fluidizing gas and enter the particle separator 122, where they are separated from the gas as a first intermediate carbonaceous product 125.

[0149] The particle separator 122 can be any device capable of separating gas from entrained particles. In some embodiments, the particle separator is a housing having a cartridge filter element 191 that allows the post-reaction gas to pass as a filtrate, but retains the entrained particles as a retentate, and an automatic backwash is promoted by a backwash gas 3236 (such as the hydrogen used) to remove the retentate from the filter medium of the cartridge. By closing valves 108A, 108E and 108F and opening valves 108B, 108D and 108F, the filter medium can be periodically backwashed during the production of the carbonaceous material. Backwashing on the cartridge filter element 191 using backwash gas 3236 removes any accumulated particles in the filter element, and the removed particles are accumulated in the product chamber 3250 as a first intermediate product 125, which is isolated from the reactor by a closed valve 108F, thereby allowing the backwash to be at a gas pressure of at least the pressure drop on the particle separator 122. After backwashing is completed, valve 108D is optionally closed and valve 108F is opened to discharge the aggregated first intermediate product 125 into the reactor 3204.

[0150] As noted above in connection with other embodiments, the second intermediate carbonaceous product 114 can exit the reactor via an open valve, door, etc. at the bottom of the reactor. In some embodiments, valve 108H can be opened (e.g., can be cyclically opened) for the product discharge phase, for example to allow the product to be removed from the reactor. The carbonaceous product can be collected in a reactor discharge silo (117, 118, or both), for example as described in reference to Figure 2A The reactor discharge silo 232 is depicted. In some embodiments, the reactor discharge silo may include or lead to a cooling circuit. Valve 108C may be used to isolate the reactor discharge silo 121 from the reactor discharge silo 117 when valve 108H is open.

[0151] experiment

[0152] The following examples are provided to illustrate certain aspects, embodiments and configurations of the present invention and should not be construed as limiting the invention as set forth in the appended claims. Unless otherwise indicated, all parts and percentages are by weight.

[0153] Example 1

[0154] The particulate catalyst was placed in a 5" quartz tube and heated by a Thermacraft wrap-around electric 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 catalyst, and the heater was activated to maintain a consistent temperature of 700°C in all zones / areas within the quartz tube. The product gas was cooled by immersing the product gas portion of the reactor in a cold water bath. The product gas was then analyzed for hydrogen (H2) and methane (CH4) gas content after 5, 10, 15, 30 and 60 minutes to determine the 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.

[0155] Table 1

[0156]

[0157] Many variations and modifications of the invention may be used.Some features of the invention may be provided without providing others.

[0158] For example, in an alternative embodiment, the inert gas curtain is provided by other nozzle or gas distribution system configurations, such as a plurality of emitters positioned around the circumference of the conduit 512 .

[0159] 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.

[0160] In another alternative embodiment, the reactor assembly is used as a fluidized bed reactor for other chemical processes and reactions (e.g., in the petroleum and chemical processing industries. For example, fluidized bed reactors can be used for: cracking and reforming of hydrocarbons (oils), coking and gasification of coal, ore roasting, Fischer-Tropsch synthesis, polyethylene manufacturing, limestone calcining, aluminic anhydride production, granulation, vinyl chloride production, combustion of waste, nuclear fuel preparation, combustion of solid, liquid and gaseous fuels, drying, adsorption, cooling, heating, freezing, transportation, storage and thermal treatment of various particulate solid materials.

[0161] In another alternative embodiment, the cone can have other geometric configurations. Examples include truncated cones, triangular prisms, rectangular-based pyramids, tetrahedrons, cylindrical prisms, spheres, rectangular prisms, pentagonal prisms, hexagonal prisms, octagonal prisms, 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 more turbulent vortex gas flow.

[0162] In various aspects, embodiments and configurations, the present invention includes components, methods, processes, systems and / or devices substantially as shown and described herein, including various aspects, embodiments, configurations, sub-combinations and subsets thereof. After understanding the present invention, those skilled in the art will understand how to make and use various aspects, embodiments and configurations. In various aspects, embodiments and configurations, the present invention includes providing devices and methods in the absence of items not shown and / or described herein or in its various aspects, embodiments and configurations (including in the absence of such items that may have been used in previous devices or methods, for example, to improve performance, achieve ease of use and / or reduce implementation costs).

[0163] The foregoing discussion of the present invention has been presented for the purpose of illustration and description. The foregoing is not intended to limit the present invention to one or more forms disclosed herein. For example, in the foregoing detailed description, various features of the present invention are grouped together in one or more aspects, embodiments and configurations for the purpose of simplifying the present invention. The features of the aspects, embodiments and configurations of the present invention may be combined in alternative aspects, embodiments and configurations other than those discussed above. The method of the present invention should not be interpreted as reflecting the intention that the present invention requires more features than the features explicitly recited in each claim. On the contrary, as reflected in the appended claims, the creative aspect is less than all the features of the single foregoing disclosed aspects, embodiments and configurations. Therefore, the following claims are hereby incorporated into the detailed description, wherein each claim itself exists independently as a separate preferred embodiment of the present invention.

[0164] In addition, although the description of the present invention has included descriptions of one or more aspects, embodiments or configurations and certain variations and modifications, other variations, combinations and modifications are also within the scope of the present invention, such as after understanding the present invention, within the skills and knowledge of those skilled in the art. The present invention is intended to obtain the right to include alternative aspects, embodiments and configurations to the extent permitted, including structures, functions, scopes or steps that are alternative, interchangeable and / or equivalent to the content claimed, regardless of whether such alternative, interchangeable and / or equivalent structures, functions, scopes or steps are disclosed herein, and no disclosure of any patentable subject matter is intended.

Claims

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, the hollow interior volume receiving a hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas through the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end, the reaction vessel and the 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, 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 particles is positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce nanomaterials.

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

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 the longitudinal axis of the reactor cylindrical sidewall.

4. The reactor system according to claim 1 further comprises a quiet zone, wherein the quiet zone is located at the upper end of the reaction vessel between the first end of the air-impermeable structure and the relative upper surface of the reaction 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 particles in the catalyst particle bed.

5. The reactor system of claim 4, wherein the pressure of the hydrocarbon-containing gas is in the range of about -100 KPa to about 100,000 KPa; wherein 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, wherein the temperature of the hydrocarbon-containing gas in the fluidized bed is in the range of about 550° C. to about 850° C., wherein the P of the particulate catalyst particles is 90 The size is in the range of about 0.1 to about 5 microns, and wherein the gas impermeable structure is an open cylinder, wherein the first end and the second end of the gas impermeable structure are spaced apart from respective opposing surfaces of the reaction vessel.

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

7. The reactor system according to claim 1, further comprising a vacuum pump, wherein the vacuum pump is positioned between a heat exchanger and a pressure swing adsorption system, wherein the vacuum pump generates a partial vacuum to cause the flow of the post-reaction gas stream, wherein the heat exchanger transfers heat from the post-reaction gas stream to the hydrocarbon-containing gas, and wherein the vacuum pump is connected to the outlet fluid of the reaction vessel.

8. A method comprising: A hydrocarbon-containing gas is introduced into an inlet of a reaction vessel comprising: a gas-impermeable structure including a sidewall having a hollow interior volume, the hollow interior volume receiving a hydrocarbon-containing gas through the first end so that the hydrocarbon-containing gas passes through the hollow interior volume, and discharging the hydrocarbon-containing gas through the second end; 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 particles positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce nanomaterials; removing post-reaction gases from an outlet conduit of the reactor; and A composite material including carbonaceous products and catalyst particles is removed from the outlet of the reactor.

9. The method of claim 8, wherein the continuous sidewall is arcuate, wherein hydrocarbons in the hydrocarbon-containing gas are catalytically decomposed into carbon nanofibers and hydrogen, wherein the one or more gas distributors comprise one or more gas injectors and / or one or more rotatable surfaces of the hydrocarbon-containing gas, wherein the hydrocarbon-containing gas comprises at least about 50 mol % methane and hydrogen, 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 ellipse and a circular cylinder, and wherein the sidewall is a surface of one of the ellipse and the circular cylinder, and wherein the one of the ellipse and the circular cylinder is substantially centered on the longitudinal axis of the cylindrical sidewall of the reactor.

11. The method of claim 8, wherein the one or more gas distributors include one or more rotatable blades, and the method further comprises: removing substantially all entrained catalyst particles from the reacted gas via a particulate separator; thereafter passing the reacted gas and the hydrocarbon-containing gas through a heat exchanger to transfer heat from the reacted gas to the hydrocarbon-containing gas to provide a cooled reacted gas and a preheated hydrocarbon-containing gas; passing the cooled post-reaction gas through a vacuum pump to create a vacuum, the vacuum causing the post-reaction gas to flow through the particle separator; and After passing through the vacuum pump, the cooled reactor gas is passed through a pressure swing adsorption system to separate a separated hydrocarbon-containing gas stream and a separated hydrogen-containing gas stream from the by-product hydrogen in the post-reaction gas, wherein the separated hydrocarbon-containing gas stream includes at least most of the unreacted hydrocarbons in the cooled reactor gas, and the separated hydrogen-containing gas stream includes at least most of the by-product hydrogen.

12. The method according to 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 a majority of the particulate catalyst in the preheated mixed gas stream; and The preheated mixed gas stream including entrained particulate catalyst is passed through an inlet of the reaction vessel, wherein a velocity of the preheated mixed gas stream before passing through the inlet exceeds a velocity of the preheated mixed gas stream after passing through the inlet.

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

1.

14. The method of claim 8, wherein removing the composite material comprises: The gas impermeable structure is moved 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 carbonaceous material from the reaction zone.

15. The method of claim 8, wherein the reaction vessel includes 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 particles in the catalyst particle bed to substantially prevent entrained catalyst particles from entering the outlet conduit; as well as During said introducing, rotating said one or more gas distributors about a longitudinal axis of said gas impermeable structure; separating the carbonaceous material from the catalyst particles to form a carbonaceous product; and The catalyst particles are recycled to the introducing step.

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, the hollow interior volume receiving a hydrocarbon-containing gas through a first end, passing the hydrocarbon-containing gas through the hollow interior volume, and discharging the hydrocarbon-containing gas through a second end, the reaction vessel and the gas-impermeable structure having a common longitudinal axis; one or more rotatable blades having axes of rotation along the common longitudinal axis 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; a bed of catalyst particles positioned in the annular volume such that the hydrocarbon-containing gas fluidizes the bed of catalyst particles to produce nanomaterials; and A quiet zone at an upper end of the reaction vessel between the first end of the air-impermeable structure and an opposite 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 particles in the catalyst particle bed.

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

18. The reactor system of claim 16, wherein the continuous sidewall is curved, wherein the pressure of the hydrocarbon-containing gas is in the range of about -100 KPa to about 100,000 KPa; wherein a first velocity of the hydrocarbon-containing gas in the hollow interior volume is in the range of about 0.015 to about 20 fps, a second velocity of the hydrocarbon-containing gas in the quiet zone is in the range of about 0.15 to about 20 fps, a third velocity of the hydrocarbon-containing gas in the fluidized bed is in the range of about 0.015 to about 20 fps, wherein a temperature of the hydrocarbon-containing gas in the fluidized bed is in the range of about 550° C. to about 850° C., wherein the P of the particulate catalyst particles is 90 The size is in the range of about 0.1 to about 5 microns, and wherein the gas impermeable structure is an open cylinder, wherein the first end and the second end of the gas impermeable structure are spaced apart from respective opposing surfaces 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 a pressure swing adsorption system, the vacuum pump generating a partial vacuum to cause flow of the reacted gas stream, wherein the heat exchanger transfers heat from the reacted gas stream to the hydrocarbon-containing gas, and wherein the vacuum pump is connected to the outlet fluid of the reaction vessel.

Images