Reactor cell for photocatalysis of gaseous species for industrial chemical production

Abstract

1. A reactor cell assembly having an annular volume, a top end cap fitting having a reactant gas inlet, a bottom compression end cap fitting having a product gas outlet, a photocatalyst packed bed positioned within the annular volume, a porous base filter for positioning the photocatalyst packed bed within the annular volume, and a light housing, wherein at least one of the outer and inner portions of the light housing includes a circumferential array of photon emitters arranged to uniformly emit photons incident on the photocatalyst packed bed to activate continuous light-induced gas phase reactions as at least one gaseous reactant introduced via the gas inlet flows through the photocatalyst packed bed and at least one resulting gaseous product exits via the gas outlet.

Description

[Technical Field]

[0001] Field FIELD OF THE DISCLOSURE

[0001] This disclosure relates to the field of industrial chemical manufacturing, and more particularly to the design and construction of reactor cells for photocatalysis of gaseous species for industrial chemical manufacturing. [Background technology]

[0002] background

[0002] Photocatalysis, as used herein, refers to the application of photons to a chemical process to accelerate the rate of chemical conversion of reactants to selectively form a desired product. Incident photons of sufficient energy and wavelength activate light-induced reactions by liberating reaction mechanisms that may otherwise be unavailable through thermally activated processes. Recent developments in photocatalysis include the use of plasmonic nanoparticles, which exhibit strong interactions with visible light due to the excitation of electronic vibrations.See, for example, the following, the contents of each of which are incorporated herein by reference: (1) Stankiewicz, “Energy Matters: Alternative Sources and Forms of Energy for Intensification of Chemical and Biochemical Processes,” Chem. Eng. Res. Des., 2006, 84 (7 A), 511-521, https: / / doi.org / 10.1205 / cherd.05214; (2) Robatjazi et al., “Plasmon-Driven Carbon-Fluorine (C(Sp 3)-F) Bond Activation with Mechanistic Insights into Hot-Carrier-Mediated Pathways,” Nat. Catal., 2020, 3 (7), 564-573, https: / / doi.org / 10.1038 / s41929-020-0466-5; (3) Zhou et al. al., “Light-Driven Methane Dry Reforming with Single Atomic Site Antenna-Reactor Plasmonic Photocatalysts,” Nat. Energy, 2020, 5 (1), 61-70, https: / / doi.org / 10.1038 / s41560-019-0517-9;(4) Gerven et al. al., “2009-VanGervenStankiewicz-Structure, Energy, Synergy, Time.pdf,” 2009, 2465-2474; and (5) Zhou et al., “Quantifying Hot Carrier and Thermal Contributions in Plasmonic Photocatalysis,” Science, 05 Oct. 2018, 69-72, https: / / doi.org / 10.1126 / science.aat6967. These plasmonic nanoparticles offer the potential for increased efficiency due to increased selectivity of desired products with reduced energy consumption.Although plasmonic nanoparticles have attracted considerable interest in academic settings for various chemical transformations, known industrial applications are limited to wastewater treatment and purification processes, all of which involve liquid-state reactions. See, e.g., Mozia, “Photocatalytic Membrane Reactors (PMRs) in Water and Wastewater Treatment: A Review,” Sep. Purif. Technol., 2010, 73 (2), 71-91, https: / / doi.org / 10.1016 / j.seppur.2010.03.021, which is incorporated herein by reference in its entirety.

[0003]

[0003] In contrast, thermal catalysts are responsible for the production of approximately 85% of all industrially produced chemicals. However, thermal catalysts generally require relatively harsh reaction conditions, such as high temperatures and pressures, which reduces process efficiency and leaves a large carbon footprint.

[0004]

[0004] The cooperative combination of photocatalysis with thermal catalysis offers the potential to increase product selectivity while reducing the energy requirements of the process. However, because combining a photon source and a heater into a single modular system poses significant industrial challenges, photothermal catalytic systems have primarily been studied in academic settings. See, for example, Nair et al., "Thermo-Photocatalysis: Environmental and Energy Applications," ChemSusChem, 2019, 12 (10), 2098-2116, https: / / doi.org / 10.1002 / cssc.201900175, the entire contents of which are incorporated herein by reference. Summary of the Invention [Problem to be solved by the invention]

[0005]

[0005] There is a need for improved reactor designs for photocatalytic and photothermal catalytic systems for industrial chemical production. [Means for solving the problem]

[0006] overview One embodiment described herein relates to a photocatalytic reactor cell assembly including an outer cell wall and an inner cell wall. The outer cell wall and the inner cell wall are concentrically arranged around a vertical axis to define an annular volume between the outer cell wall and the inner cell wall. A top end cap fitting having a reactant gas inlet and a bottom end cap fitting having a product gas outlet form top and bottom seals with the outer cell wall and the inner cell wall, respectively. A photocatalytic packed bed is positioned within the annular volume between the outer cell wall and the inner cell wall by a porous base filter. The light housing includes a photon emitter arranged to uniformly emit photons incident on the photocatalytic packed bed to activate a continuous light-induced gas-phase reaction as at least one gaseous reactant introduced via the gas inlet flows through the photocatalytic packed bed and at least one resulting gaseous product exits via the gas outlet.

[0007]

[0007] One or more cooling structures and / or mechanisms may be provided to cool the photon emitter and / or portions of the optical housing in which the photon emitter is mounted.

[0008]

[0008] One or more heaters may be provided to heat the photocatalyst packed bed to enhance the reaction rate of the photoinduced gas phase reaction.

[0009]

[0009] These and other embodiments, aspects, advantages, and alternatives will become apparent to those skilled in the art upon reading the following detailed description, with reference, where appropriate, to the accompanying drawings. Furthermore, this summary, as well as the other descriptions and figures provided herein, are intended to illustrate embodiments by way of example only, and therefore, many variations are possible. For example, structural elements and process steps may be rearranged, combined, distributed, excluded, or otherwise modified while remaining within the scope of the claimed embodiments.

[0010] BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the systems, apparatus, devices, and / or methods of the present disclosure and are incorporated into and constitute a part of this specification. The drawings are not necessarily to scale, and sizes of various elements may be distorted for clarity and / or shown as simplified diagrams to facilitate understanding. The drawings illustrate one or more embodiments of the present disclosure and, together with the description, serve to explain the principles and operation of the present disclosure. [Brief explanation of the drawings]

[0011] [Figure 1]

[0011] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 2]

[0012] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 3]

[0013] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 4]

[0014] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 5]

[0015] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 6]

[0016] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 7]

[0017] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 8]

[0018] FIG. 1 is an elevational view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 9]

[0019] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 10]

[0020] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 11]

[0021] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 12]

[0022] FIG. 1 is an elevation view illustrating a single IR lamp that may be used as a photon emitter and / or heater component, according to an example embodiment. [Figure 13]

[0023] 1 is a schematic cross-sectional view illustrating a single IR lamp that may be used as a photon emitter and / or heater component, according to an example embodiment. [Figure 14]

[0024] 1 is a table illustrating three categories of infrared radiation for industrial applications. [Figure 15]

[0025] 1 is a graph showing the percentage of radiation transmission as a function of wavelength for quartz. [Figure 16]

[0026] 1 is a graph showing the absorption of IR radiation for various gas species as a function of wavelength. [Figure 17]

[0027] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 18]

[0028] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 19]

[0029] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 20]

[0030] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 21]

[0031] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 22]

[0032] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 23]

[0033] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 24]

[0034] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 25]

[0035] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 26]

[0036] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 27]

[0037] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 28]

[0038] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 29]

[0039] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 30]

[0040] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly according to an example embodiment. [Figure 31]

[0041] 1 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 32]

[0042] 1 is a cross-sectional view illustrating a photocatalytic reactor cell assembly according to an exemplary embodiment. [Figure 33]

[0043] FIG. 1 is a vertical cross-sectional view showing details of a top seal for a photocatalytic reactor cell assembly according to an example embodiment. [Figure 34]

[0044] FIG. 10 is a vertical cross-sectional view showing details of a top seal for a photocatalytic reactor cell assembly according to another exemplary embodiment. [Figure 35]

[0045] FIG. 10 is a vertical cross-sectional view showing details of a top seal for a photocatalytic reactor cell assembly according to yet another exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Detailed Description

[0046] Exemplary systems, devices, apparatus, and / or methods are described herein. It should be understood that the word "example" is used to mean "serving as an example, instance, or illustration." Any embodiment or feature described herein as being "example" is not necessarily to be construed as preferred or advantageous over other embodiments or features, unless so stated. As such, other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein. The aspects described herein are not limited to specific embodiments, devices, or configurations, and as such, may, of course, vary. It should be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings, can be arranged, substituted, combined, separated, and designed in a wide variety of different ways. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting, unless specifically defined herein.

[0013]

[0047] Throughout this specification, unless the context requires otherwise, the words "comprise" and "comprises" and variations (e.g., "include," "including," "comprises," "comprising," "comprising," "has," and "having") will be understood to imply the inclusion of a stated component, feature, element or step or group of components, features, elements or steps, but not the exclusion of any other component, feature, element or step or group of components, features, elements or steps.

[0014]

[0048] Furthermore, unless the context suggests otherwise, the features shown in each of the drawings may be used in combination with one another, and as such, the drawings should be considered as a whole as component aspects of one or more overall embodiments, with the understanding that not all described features are essential to each embodiment.

[0015]

[0049] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0016]

[0050] Ranges may be expressed herein as from "about" one particular value and / or to "about" another particular value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0017]

[0051] Any recitation of elements, blocks, or steps in the specification or claims is for clarity purposes, and therefore such recitation should not be construed as requiring or implying that these elements, blocks, or steps adhere to a particular arrangement or be performed in a particular order.

[0018] I. Overview

[0052] An effective and functional photocatalytic reactor is designed to facilitate chemical reactions by uniformly illuminating the catalyst in contact with the reactants with a photon source. Irradiation can be achieved by using natural light sources (e.g., the sun) or artificial light sources (e.g., IR lamps, UV lamps, arc lamps, or light-emitting diodes (LEDs)). Typical reactor configurations include slurry reactors, annular reactors, immersion reactors, and fiber optic / tube reactors. See, for example, Van Gerven et al., "A Review of Intensification of Photocatalytic Processes," Chem. Eng. Process. Process Intensif., 2007, 46 (9 SPEC. ISS.), 781-789, which is incorporated herein by reference in its entirety. See https: / / doi.org / 10.1016 / j.cep.2007.05.012. Challenges in process intensification of these reactors arise primarily from photon and mass transport limitations. Research on photocatalytic reactors for the conversion of gas species is still in its early stages, and applicants are unaware of any reported cases that have been successfully scaled up from laboratory facilities to industrially relevant scales. Difficulties in reactor design and material selection, as well as an incomplete understanding of critical parameters important to reactor design, have hindered past development efforts. See, e.g., de Lasa et al., “Photocatalytic Reaction Engineering,” Springer, Boston, MA, 2005, https: / / doi.org / 10.1007 / 0-387-27591-6.

[0019]

[0053] Several large-scale photocatalytic reactors have been proposed, and among these designs, slurry reactors, annular reactors, submerged reactors, and light-tube reactors have been tested exclusively for liquid-state reactions in the wastewater treatment field. See, for example, de Lasa et al., "Photocatalytic Reaction Engineering," Springer, Boston, MA, 2005. The light source in such reactors is oriented to illuminate the reactor's longitudinal axis to promote photocatalytic treatment of the wastewater. The catalyst within the reactor is either fluidized by the wastewater or immobilized by a support material. Commonly reported drawbacks associated with these types of reactors center around the lack of uniform irradiance of the photocatalyst and mass transfer limitations associated with insufficient contact between the photocatalyst and the fluid. Strategies to improve mixing and overcome mass transfer limitations include the use of rotors and / or impellers within the reactor to introduce turbulence into the fluid. See, for example, U.S. Patent Application Publication No. 20130008857A1. More recently, photocatalytic reactors have been used for the removal of volatile organic components as part of air purification modules. See, e.g., U.S. Patent Application Publication No. 20210023255A1. These reactor designs incorporate "fins" or directional blades to improve mass transfer and contact between the air and the coated photocatalyst.

[0020]

[0054] Implementation of these processes at scales beyond those studied in research and development environments has been hindered for a variety of reasons. Photocatalytic reactor development lacks the decades of experience associated with thermocatalytic reactors. A solid understanding of the fundamental processes underlying thermocatalytic reactors facilitates the scaling up of laboratory-scale thermocatalytic reactor processes to pilot scale and beyond. Thermocatalytic reactors also benefit from validated numerical and kinetic modeling. Conversely, research on photocatalytic and photothermal catalytic processes has instead focused on elucidating product formation and reaction kinetics and gaining a mechanistic understanding of the underlying chemical phenomena. The inclusion of photons in photocatalysis causes the reactor performance to deviate considerably from traditional thermocatalytic reactors. Added complications include the selection of a suitable light source and reactor geometry, which affect the photon behavior and catalytic performance of the process. These unknowns add significant variability to scale-up and process intensification. See, for example, Pasquali et al., "Radiative Transfer in Photocatalytic Systems," AIChE J., 1996, 42 (2), 532-537, https: / / doi.org / 10.1002 / aic.690420222 and Alfano et al., "Photocatalysis in Water Environments Using Artificial and Solar Light," 2000; Vol. 58, https: / / doi.org / 10.1016 / S0920-5861(00)00252-2, both of which are incorporated herein by reference.

[0021]

[0055] Other complexities have contributed to the relatively slow development of photocatalytic reactor design. See, for example, Su et al., "Photochemical Transformations Accelerated in Continuous-Flow Reactors: Basic Concepts and Applications," Chem. - A Eur. J., 2014, 20 (34), 10562-10589. https: / / doi.org / 10.1002 / chem.201400283, which is incorporated herein by reference in its entirety. One such consideration includes the selection of materials for reactor cell construction, as photocatalytic processes require a transparent window through which light or photons can irradiate the catalyst. The reactor geometry should also be optimized for photon transport so that light loss is minimized and photon flux is focused on the catalyst bed. Photocatalytic reactor cell design should also facilitate gas-solid mixing and transport properties to promote optimal catalytic performance. Fabrication of a stainless steel and glass-based pilot-scale photocatalytic reactor within design specifications is an engineering challenge that has been an obstacle to further development. The inclusion of reflective materials, control electronics for the photon source, and auxiliary processes to support photocatalytic reactor function has significantly complicated the development of photocatalytic reactors.

[0022]

[0056] To address some of the shortcomings of conventional photocatalytic reactor cells, various embodiments of improved reactor cell assemblies for photocatalysis of gaseous species for industrial chemical production are disclosed herein. Reactor cell embodiments of the present disclosure include exemplary reactor cells that can carry out chemical reactions with a feed gas using incident photons (i.e., light) across a packed bed of photocatalyst disposed in an annular portion of the reactor cell having an outer cell wall and an inner cell wall. In some exemplary embodiments, one or both of the outer cell wall and the inner cell wall are transparent. Other reactor cell embodiments are also described herein.

[0023]

[0057] The exemplary embodiments described herein generally relate to photocatalytic reactor cells that are annular in nature and include a nanoparticle photocatalyst packed bed. The annular region can be made of materials transparent to the visible and near-IR regions. Gaseous reactants flow through the photocatalyst packed bed, similar to that in a plug-flow reactor, allowing for continuous reaction and production of desired products. Energy for the photocatalyst can be provided on one or both sides (i.e., outside and / or inside) of the annular region via a light housing, which can have, for example, multiple photon emitters, such as light-emitting diodes (LEDs) or IR lamps, attached to or functioning in multiple portions of the light housing. Specific geometries and the use of transparent, reflective, or scattering materials enable efficient methods of delivering light energy to the photocatalyst, promoting efficient chemical reaction. In some embodiments, the light housing can include a cooling assembly to assist in cooling the photon emitters and / or the surface to which the photon emitters are attached. In some other embodiments, one or more heaters can be included to enhance the photocatalytic reaction rate.

[0024]

[0058] Some embodiments described herein enable reduced reliance on fossil fuels and reduced carbon emissions. For example, embodiments having LEDs as photon emitters may use electricity to activate the LEDs. Such electricity may be generated using renewable resources, such as solar, hydroelectric, or wind power. As a result, environmental benefits may be realized for industrial chemical reactions that have traditionally been performed by thermocatalysis using thermal energy generated by the combustion of fossil fuels.

[0025]

[0059] Chemical reactions that may be carried out in various embodiments of reactor cells described herein traditionally require very high temperatures due to the high enthalpy of the reactions. Conventional thermal catalytic reactors are typically made of relatively expensive materials that can withstand such high temperatures. Furthermore, conventional thermal catalytic reactors are typically provided with thermal energy in an inefficient and environmentally unfriendly manner by burning fossil fuels. Conversely, various reactor cell embodiments described herein may support carrying out these same chemical reactions in the presence of visible light at temperatures much lower than those required for conventional thermal catalytic reactors. This allows for the use of relatively inexpensive materials, such as glass or aluminum, in the construction of the reactor. Furthermore, the associated lower operating temperatures may extend the life of reactor components for the exemplary photocatalytic reactors described herein.

[0026]

[0060] The various reactor cell assembly embodiments described herein can serve as a platform technology that uses light energy to enable multiple gas-phase chemical reactions that require high enthalpy reactions and high activation energies. For example, the following is a non-exclusive list of possible reactions and reaction types using one or more exemplary embodiments described herein: 1. Steam methane reforming. 2. Dry methane reforming. 3. Partial oxidation of methane. 4. Autothermal reforming. 5. Decomposition of ammonia. 6. Ammonia synthesis. 7. Water-gas shift reaction. 8. Reverse water gas shift reaction. 9. Modification of heavier hydrocarbons (e.g., alkylated cyclics, resins, and asphaltenes). 10. Fischer-Tropsch synthesis. 11. Methanol synthesis. 12. Ethanol synthesis. 13. Hydrogenation to make saturated compounds. 14. Dehydrogenation to make ethylene. 15. Cleavage of carbon-halogen bonds, e.g., C-F, C-Cl, C-I.

[0027] II. Reactor Cell Assembly for Photocatalysis of Gaseous Species A. Reactor cell assembly with cooled outer and inner LED light housings

[0061] FIG. 1 is an isometric view illustrating a photocatalytic reactor cell assembly 100 according to a first exemplary embodiment. FIG. 2 is a longitudinal cross-sectional view illustrating a photocatalytic reactor cell assembly 100 according to the first exemplary embodiment. FIG. 3 is a cross-sectional view illustrating a photocatalytic reactor cell assembly 100 according to the first exemplary embodiment. FIG. 4 is a longitudinal cross-sectional view illustrating a photocatalytic reactor cell assembly 100 with a photocatalyst installed according to the first exemplary embodiment. The following description of the first exemplary embodiment will refer to features and components shown in one or more of FIGS. 1-4, with like reference numerals referring to like features and components. As with all figures referenced herein, one or more of FIGS. 1-4 may omit certain features and / or components as appropriate to facilitate better explanation and understanding.

[0028]

[0062] As shown, the photocatalytic reactor cell assembly 100 includes an outer cell wall 102 including a first tube 104 having a first outer diameter 106 and a first inner diameter 108. The photocatalytic reactor cell assembly 100 also includes an inner cell wall 110 including a second tube 112 having a second outer diameter 114 and a second inner diameter 116, where the second outer diameter 114 is smaller than the first inner diameter 108. The outer cell wall 102 and the inner cell wall 110 are concentrically arranged about a vertical axis 118 to define an annular volume 120 between the outer cell wall 102 and the inner cell wall 110.

[0029]

[0063] 1-4 (and other embodiments shown herein), the first tube 104 and the second tube 112 are cylindrical and have circular cross-sections. In other embodiments, the first tube 104 and / or the second tube 112 may have a non-cylindrical shape. For example, one or both of the first tube 104 or the second tube 112 may be constructed of a tube having a square, hexagonal, octagonal, or other regular polygonal cross-section. For embodiments using a non-circular cross-section for the first tube 104 and / or the second tube 112, the term "diameter" is intended to refer to the perpendicular distance between the vertical axis 118 and a side (or corner) of the first tube 104 and / or the second tube 112, and the term "annular volume" is intended to refer to the shaped volume between the outer cell wall 102 and the inner cell wall 110. Additionally, the first outer diameter 106 and / or the first inner diameter 108 of the first tube 104 may vary over the height (length) of the first tube 104, such as when a central portion of the first tube 104 is wider than the end portions. Similarly, the second outer diameter 114 and the second inner diameter 116 of the second tube 112 may vary over the height (length) of the second tube 112. For example, the first tube 104 and / or the second tube 112 may have two or more cylindrical sections of different diameters, each joined end-to-end via an angled connecting section that acts as a size adapter between the different cylindrical sections.

[0030]

[0064] 1-4, at least a portion of both the outer cell wall 102 and the inner cell wall 110 are constructed of a material that is transparent to photons emitted by the photon emitter (as described in more detail below). For example, the outer cell wall 102 and the inner cell wall 110 may be constructed of a material that is transparent to photons in the visible light spectrum. As another example, the outer cell wall 102 and the inner cell wall 110 may be constructed of a material that is transparent to photons in the near-infrared (near-IR) spectrum. Thus, the outer cell wall 102 and / or the inner cell wall 110 may be constructed of one or more of, but not limited to, glass, fused silica glass, borosilicate glass, or a metallic material. As another alternative, the outer cell wall 102 and / or the inner cell wall 110 may be constructed of a transparent ceramic material, such as one of the materials described in Kachaev, AA, Grashchenkov, DV, Lebedeva, YE et al. Optically Transparent Ceramic (Review). Glass Ceram 73, 117-123 (2016). https: / / doi.org / 10.1007 / s10717-016-9838-3. In embodiments that use only heating (and not photon emission) adjacent either or both of the outer cell wall 102 and / or the inner cell wall 110, the outer cell wall 102 and / or the inner cell wall 110 may comprise a coated or polished metal (e.g., stainless steel or aluminum).

[0031]

[0065] As shown in Figures 2 and 4, the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 can include two or more portions along its height (length), such as a center portion 122 and an upper portion 124. The center portion can be filled with a photocatalyst packed bed 126, as shown in Figure 4, while the upper portion 124 can serve as a headspace 128 to allow for mixing of reactant gases. The upper portion 124 can be empty, as shown in Figure 4, or can be at least partially occupied by a gas mixing material, such as quartz wool, SiC, or beads (e.g., alumina and / or silica beads). Additionally, the upper portion 124 can be heated, for example, by one or more internal heaters and / or external clamp heaters (not shown).

[0032]

[0066] A photocatalyst packed bed 126 is positioned in the annular volume 120 between the outer cell wall 102 and the inner cell wall 110. The photocatalyst packed bed 126 has a photocatalyst on a support material. For example, the photocatalyst packed bed 126 can include a photocatalyst co-precipitated with a support material. The photocatalyst can include, for example, antenna-reactor plasmonic nanoparticles. Various antenna-reactor catalysts developed by Rice University, described in U.S. Pat. No. 10,766,024, incorporated herein by reference, can effectively use light energy to carry out various chemical reactions. For example, such antenna-reactor catalysts can be used in the reactor cell embodiments described herein to provide high conversion at high space velocities, resulting in high hydrogen production rates per unit volume of catalyst bed. Depending on the type of chemical reaction being carried out, an appropriate antenna-reactor catalyst is matched with a correspondingly appropriate LED diode to efficiently activate the photocatalyst, thereby providing a high reaction rate. For example, in the case of photocatalytic steam methane reforming (PSMR), high reaction rates equal to 270 micromol / g / s were achieved using an appropriate photocatalyst in the reactor cell embodiments described herein.

[0033]

[0067] In some embodiments, only a portion of the outer cell wall 102 and / or the inner cell wall 110 is transparent to photons. This transparent portion of the outer cell wall 102 and / or the inner cell wall 110 may correspond to the central portion 122 of the annular volume 120 shown in FIGS. 2 and 4 , such that the transparent portion of the outer cell wall 102 and / or the inner cell wall 110 is directly adjacent to the packed photocatalyst bed 126. For example, in one embodiment, at least a first portion of at least one of the outer cell wall 102 and / or the inner cell wall 110 is constructed of a material that is transparent to photons emitted by the photon emitter, while at least a second portion of at least one of the outer cell wall 102 and the inner cell wall 110 includes one or more reflective surfaces to reflect any randomly emitted photons into the packed photocatalyst bed 126. In another exemplary embodiment, at least a first portion of at least one of the outer cell wall 102 and the inner cell wall 110 is constructed of a material that is transparent to photons emitted by the photon emitter, while at least a second portion of at least one of the outer cell wall 102 and the inner cell wall 110 includes one or more scattering surfaces to scatter any emitted random photons into the photocatalytic packed bed 126. The "second portion" referred to in each of the two previously described embodiments may correspond to the upper portion 124 of the annular volume 120 shown in FIGS. 2 and 4, such that the second portion is directly adjacent to the headspace 128 and / or the portion of the annular volume 120 below the photocatalytic packed bed 126 (i.e., the opposite side of the photocatalytic packed bed 126 from the headspace 128). In yet another exemplary embodiment, both reflective and scattering surfaces may be included in the outer cell wall 102 and / or the inner cell wall 110, or may be included in other components of the photocatalytic reactor cell 100.

[0034]

[0068] The use of reflective and / or scattering surfaces can help minimize heat loss from the reactor cell assembly 100. Based on multiphysics simulation modeling using COMSOL, it has been determined that heat loss can be minimized using one or more of the following principles: (a) using appropriate materials in different parts of the reactor to minimize or advantageously reuse radiant heat transferred from the excited catalyst bed to other parts of the reactor; (b) using appropriate insulation in different parts of the reactor; and (c) minimizing the use of metals in the reactor and instead using materials with lower thermal conductivity (e.g., glass or quartz), thereby increasing resistance to heat transfer from the photocatalytic reactor cell assembly 100 to the environment. Reactor cell embodiments described herein operate at much lower temperatures than conventional thermal reactors, allowing for the use of materials such as quartz, aluminum, and ceramics. This may reduce energy loss from the reactor cell assembly 100, potentially improving energy efficiency compared to conventional reactors.

[0035]

[0069] As shown in FIG. 4 , a porous base filter 130 may be included within the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 to position the photocatalytic packed bed 126 within the annular volume 120. The photocatalytic reactor cell assembly 100 is oriented vertically (perpendicular to the ground) with respect to gravity or other forces (not shown, but believed to originate from the bottom of FIG. 4 ), and the porous base filter 130 is preferably located on the lower (i.e., bottom) surface of the photocatalytic packed bed 126. The porous base filter 130 has a plurality of openings (pores) with pore sizes selected to be gas permeable (allowing the flow of one or more resulting gaseous products) but impermeable to the photocatalytic packed bed 126. For example, the pore size is selected to be impermeable to the micron-sized aggregates of photocatalytic nanoparticles and the support material (e.g., aerogel) within the photocatalytic packed bed 126. The porous base filter 130 is constructed of a gas-permeable structural material, such as, but not limited to, one of porous metal, stainless steel (SS316), austenitic nickel-chromium-based alloy, nickel-chromium-iron-molybdenum alloy, quartz wool, or ceramic. When both the outer cell wall 102 and the inner cell wall 110 are cylindrical, the porous base filter 130 preferably has an annular shape corresponding to the shape of the annular volume 120.

[0036]

[0070] Table 1 below sets forth exemplary physical dimensions for various exemplary reactor cell embodiments described herein.

[0037] [Table 1]

[0038]

[0071] The photocatalytic reactor cell 100 shown in FIGS. 1-4 includes a light housing including an outer portion 132a and an inner portion 132b. While both the outer portion 132a and the inner portion 132b of the light housing are shown, in some embodiments, either the outer portion 132a or the inner portion 132b may be omitted from the light housing. The outer portion 132a of the light housing is concentrically disposed about the vertical axis 118 outside the outer cell wall 102. The inner portion 132b of the light housing is concentrically disposed about the vertical axis 118 inside the inner cell wall 110. In the example of FIGS. 1-4, both the outer portion 132a and the inner portion 132b have circumferential arrays of photon emitters arranged to uniformly emit photons incident on the photocatalytic packed bed 126. The circumferential array 142a of photon emitters in the outer portion 132a of the light housing is positioned to emit photons toward the photocatalytic packed bed 126 (i.e., toward the interior of the outer portion 132a). The circumferential array 142b of photon emitters in the inner portion 132b of the light housing is positioned to emit photons toward the photocatalytic packed bed 126 (i.e., generally away from the interior of the inner portion 132b). For example, the circumferential array 142a of photon emitters may be positioned on the inner surface of the outer portion 132a, and the circumferential array 142b of photon emitters may be positioned on the outer surface of the inner portion 132b, to uniformly emit photons incident on the photocatalytic packed bed 126. As another example, the circumferential array of photon emitters 142a may be arranged as a plurality of light bulbs emitting photons toward the interior of outer portion 132a, and the circumferential array of photon emitters 142b may be arranged as a plurality of light bulbs emitting photons toward the exterior of inner portion 132b, uniformly emitting photons that are incident on the photocatalyst packed bed 126. The photon emissions that are incident on the photocatalyst packed bed 126 activate continuous light-induced gas-phase reactions as at least one gaseous reactant flows through the photocatalyst packed bed 126, resulting in at least one gaseous product.

[0039]

[0072] In some exemplary embodiments, the outer portion 132a of the light housing is of an outward-opening clamshell design and includes two (or more) sections joined by a hinge (not shown) to allow for installation or removal of the outer portion 132a within the photocatalytic reactor cell assembly 100. Similarly, the inner portion 132b of the light housing may be of an inward-opening clamshell design that includes two (or more) sections joined by a hinge (not shown) to allow for installation or removal of the inner portion 132b within the photocatalytic reactor cell assembly 100.

[0040]

[0073] As shown in FIGS. 1-4, both the outer portion 132a and the inner portion 132b of the light housing are cylindrical with a circular cross-section. In other embodiments, the outer portion 132a and / or the inner portion 132b of the light housing may have a non-cylindrical shape. For example, the outer portion 132a and / or the inner portion 132b of the light housing may have a square, hexagonal, octagonal, or other regular polygonal cross-section to match the cross-sectional shape of the first tube 104 and / or the second tube 112. Furthermore, the cross-sectional width of the outer portion 132a and / or the inner portion 132b may vary across the height (length) of the outer portion 132a and / or the inner portion 132b, such as when the central portion of the outer portion 132a and / or the inner portion 132b is wider than the end portions. For example, the outer portion 132a and / or the inner portion 132b may have two or more cylindrical portions with different diameters, each of which is joined end-to-end via an angled connecting portion that acts as a size adapter between the different cylindrical portions of the outer portion 132a and / or the inner portion 132b of the light housing.

[0041]

[0074] The exterior of the outer portion 132a of the light housing may be shaped differently than the interior of the outer portion 132a. For example, instead of both its interior and exterior being cylindrical, the outer portion 132a may be cylindrical on its interior but surrounded by other devices, components, and / or materials, such as thermal management and / or control devices, components, and / or materials, to give the exterior a non-cylindrical shape. Similarly, the interior of the inner portion 132b of the light housing may be shaped differently than the exterior of the inner portion 132b. For example, instead of being entirely hollow as shown in FIGS. 1-4, the inner portion 132b may instead be solid or filled with other devices, components, and / or materials.

[0042]

[0075] As shown in Figures 1-4 and several other figures herein, some or all of the photon emitters in the circumferential array of photon emitters on outer portion 132a and / or inner portion 132b may be mounted on LED circuit boards or other forms of LEDs. For example, the circumferential array of photon emitters on outer portion 132a and / or inner portion 132b may include multiple adjacent LED boards, each containing multiple LEDs, e.g., several thousand LEDs, each about 1-5 mm in diameter. The LEDs may be selected to emit photons in the visible light spectrum (i.e., about 380 nm to about 750 nm). Alternatively or additionally, some or all of the photon emitters in the circumferential array of photon emitters on outer portion 132a and / or inner portion 132b may be infrared (IR) lamps attached via sockets, connectors, pins, wires, or other forms to emit photons in the near-IR spectrum (i.e., about 750 nm to about 2,500 nm). Further details regarding the use of IR bulbs as photon emitters (and / or heaters) are presented, particularly with respect to Figures 9-16. Other embodiments may include other types of photon emitters, both artificial (e.g., ultraviolet (UV) lamps and galvanic arc lamps) and natural (e.g., using solar radiation). Generally, to facilitate efficient operation of the photocatalytic reactor cell assembly 100, the photon emitter is selected to emit photons having sufficient energy and wavelength to activate the desired photoinduced gas-phase reaction.

[0043]

[0076] The photocatalytic reactor cell assembly 100 may also include integrated control electronics for controlling the photon emitters and a driver for driving the photon emitters. For example, the LED driver may be selected to operate at a power load of 50% or more to improve driver efficiency during operation of the photocatalytic reactor cell assembly 100. A system of several or many photocatalytic reactor cell assemblies 100 may, for example, share at least some common electronics. In addition to operating the LED driver at a power load of 50% or more during operation, another design consideration for efficient light delivery is varying the operating current to enable the LEDs to operate at maximum efficiency. Furthermore, the LEDs themselves may be selected to have high photon efficiency within the same spectral range as the photocatalyst (e.g., the same visible spectral range). Diodes of different semiconductor materials are available with different specific electrical-to-photon energy efficiencies. Selecting a diode with high photon efficiency within the same range as the photocatalyst may increase light absorption by the catalyst.

[0044]

[0077] The outer portion 132a of the light housing may be attached to the outer cell wall 102 (e.g., by epoxy, adhesive, or mechanical fasteners). The inner portion 132b of the light housing may be attached to the inner cell wall 110 (e.g., by epoxy, adhesive, or mechanical fasteners). Alternatively, the outer portion 132a and / or inner portion 132b of the light housing may simply be positioned adjacent to and in close proximity to the outer cell wall 102 and inner cell wall 110, respectively, without being physically attached. As yet another alternative, the respective separation distances between (a) the outer portion 132a and / or inner portion 132b of the light housing and (b) the outer cell wall 102 and inner cell wall 110, respectively, may be selected to achieve a desired illumination geometry. For example, either or both of the outer portion 132a and inner portion 132b may have a small separation distance between themselves and the outer cell wall 102 and inner cell wall 110, respectively. As another example, either the outer portion 132a or the inner portion 132b may have a small separation relative to the outer cell wall 102 or the inner cell wall 110, while the other has a relatively large separation. Separation 208 is shown as an exemplary separation between the inner cell wall 110 and the inner portion 132b of the light housing. Alternatively or additionally, the outer portion 132a and / or the inner portion 132b of the light housing may include a frame or other structure to which a circumferential array of photon emitters is attached, which may or may not be directly attached to the outer cell wall 102 and / or the inner cell wall 110. For example, such a frame or other structure may be constructed of aluminum, stainless steel (SS316), or some other material. The outer portion 132a and / or the inner portion 132b of the light housing may have a single unitary frame or structure, or may have multiple frames or structures, such as one frame or structure on the outer portion 132a of the light housing and another frame or structure on the inner portion 132b of the light housing. In some embodiments, one or more mounting frames or structures for the circumferential array(s) of photon emitters may act as cooling structures in the form of cooling jackets, heat sinks, or other heat dissipation mechanisms.

[0045]

[0078] The embodiment shown in FIGS. 1-4 includes cooling structures in the form of an outer cooling block 134 and an inner cooling block 138. The outer cooling block 134 is associated with the outer portion 132a of the light housing, while the inner cooling block 138 is associated with the inner portion 132b of the light housing. As shown, the outer cooling block 134 has a plurality of outer coolant passages 136, and the inner cooling block 138 has a plurality of inner coolant passages 140. While multiple coolant passages are shown in the example of FIGS. 1-4, alternatively or in addition, the outer cooling block 134 and / or the inner cooling block 138 may include hollow-walled reservoirs through which a cooling fluid is circulated in whole or in part. For example, the outer cooling block 134 and / or the inner cooling block 138 may include walls (e.g., aluminum walls, which may be a cost-effective embodiment) defining receptacles through which a cooling fluid is passed at a predetermined flow rate. In one exemplary embodiment, the outer cooling block 134 and / or the inner cooling block 138 function solely as a heat sink and do not use a cooling fluid. In the case of LEDs used as photon emitters, the cooling structure may, for example, maintain the surface on which the photon emitters are mounted at a temperature of 150 degrees Celsius or less.

[0046]

[0079] Generally, the outer portion 132a of the light housing may include an outer cooling block 134, and the inner portion 132b of the light housing may include an inner cooling block 138. The outer cooling block 134 and / or the inner cooling block 138 may be configured to assist in cooling the photon emitters and / or associated electronics, such as LED drivers. For example, a circumferential array of photon emitters may include multiple LEDs (on LED boards) mounted on at least one wall (e.g., an aluminum wall) of one or more cooling blocks 134 and / or 138, such that cooling fluid passing through one or more coolant passages and / or one or more receptacles in each cooling block assists in cooling the multiple LED boards. Coolant may be introduced to and removed from one or more cooling blocks 134 and / or 138 via one or more coolant lines that interface with the outer coolant passage 136 and / or the inner coolant passage 140. Such coolant lines (not shown) may recirculate / reuse the coolant (after appropriate heat removal or dissipation) and / or may introduce new coolant and remove old coolant without recirculation.

[0047]

[0080] The cooling fluid used in the outer cooling block 134 and / or the inner cooling block 138 may be selected to have a predetermined heat capacity. The cooling fluid (or coolant) may be selected, for example, from the following non-exclusive list: ammonia, synthetic hydrocarbons of aromatic chemistry (i.e., diethylbenzene [DEB], dibenzyltoluene, diaryl alkyls, partially hydrogenated terphenyls), silicate esters, aliphatic hydrocarbons of the paraffin and isoparaffin type, dimethyl and methylphenyl-poly(siloxanes), fluorinated compounds such as perfluorocarbons (i.e., FC-72, FC-77), hydrofluoroethers (HFEs) and perfluorocarbon ethers (PFEs), ethylene glycol, propylene glycol, methanol / water, ethanol / water, calcium chloride solution (e.g., 29 wt%), aqueous solutions of potassium formate and acetate, and liquid metals (e.g., Ga-In-Sn).

[0048] B. End cap fittings, seals, tension rods, gas inlets and outlets

[0081] FIG. 5 is an isometric view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIG. 6 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly according to an exemplary embodiment. FIGS. 5 and 6 use the same reference numerals as in FIGS. 1-4 to refer to the same or similar features and / or components. Either or both of FIGS. 5 and 6 may omit certain features and / or components from those shown in FIGS. 1-4 (or each other), as appropriate, to facilitate better explanation and understanding. For example, FIGS. 5 and 6 omit at least the outer cooling block 134, the inner cooling block 138, details of the outer and inner portions 132a and 132b of the light housing, the photocatalytic packed bed 126, and the porous base filter 130. FIGS. 5 and 6 are presented primarily to illustrate the top and bottom end cap fittings of the photocatalytic reactor cell assembly 100, along with various features and components and features associated with the top and bottom end cap fittings.

[0049]

[0082] As shown, the photocatalytic reactor cell assembly 100 includes a top compression end cap fitting 144 having an annular shape. The top compression end cap fitting 144 includes one or more (e.g., four) reactant gas inlets 146 that accept a continuous flow of input gaseous reactant feedstock, which may include one or more component reactant gases. The top compression end cap fitting 144 may have a first peripheral flange 148 that fits around a top portion 150 of the outer cell wall 102, a first inner peripheral flange 152 that fits inside or outside a top portion 154 of the inner cell wall 110, or both the first peripheral flange 148 and the first inner peripheral flange 152. While the above description and FIGS. 5 and 6 show a cylindrical (annular) shape for the top compression end cap fitting 144, a circular shape could be used instead. As yet another alternative, a non-cylindrical (non-annular) shape may be suitable for a first tube 104 having a non-circular cross-section. For example, the top compression end cap fitting 144 may have a cross section that matches the regular polygonal cross section of the first tube 104. Additionally, in some embodiments, either or both of the first outer circumferential flange 148 and the first inner circumferential flange 152 may be omitted.

[0050]

[0083] As also shown, the photocatalytic reactor cell assembly 100 includes a bottom compression end cap fitting 156 having an annular shape. The bottom compression end cap fitting 156 has one or more (e.g., four) product gas outlets 158 for outputting a continuous stream of gaseous products, which may include one or more component product gases. The bottom compression end cap fitting 156 has a second peripheral flange 160 that fits around a bottom portion 162 of the outer cell wall 102, a second inner peripheral flange 164 that fits inside or outside a bottom portion 166 of the inner cell wall 110, or both the second peripheral flange 160 and the second inner peripheral flange 164. While the above description and FIGS. 5 and 6 show a cylindrical (annular) shape for the bottom compression end cap fitting 156, a circular shape could be used instead. As yet another alternative, a non-cylindrical (non-annular) shape could be suitable for a first tube 104 having a non-circular cross-section. For example, the bottom compression end cap fitting 156 may have a cross-section that matches the regular polygonal cross-section of the first tube 104. Additionally, in some embodiments, either or both of the second outer circumferential flange 160 and the second inner circumferential flange 164 may be omitted.

[0051]

[0084] The top compression end cap fitting 144 and the bottom compression end cap fitting 156 may be constructed of, for example, stainless steel (SS316), an austenitic nickel-chromium-based alloy, a nickel-chromium-iron-molybdenum alloy, or aluminum. Alternatively or additionally, the top compression end cap fitting 144 and the bottom compression end cap fitting 156 may be constructed of other materials, such as materials with low thermal expansion coefficients. Furthermore, the portion of at least one of the top compression end cap fitting 144 and the bottom compression end cap fitting 156 that faces the photocatalyst packed bed 126 (i.e., the portion facing inward) may be polished to reflect emitted photons into the photocatalyst packed bed 126. Alternatively, to achieve a similar purpose, a reflective coating (not shown) may be deposited or attached to the top compression end cap fitting 144 and / or the bottom compression end cap fitting 156 that face the photocatalyst packed bed 126.

[0052]

[0085] The top and bottom compression end cap fittings 144, 156 form top and bottom seals 168, 170 with the outer and inner cell walls 102, 110, respectively. Either or both of the top and bottom seals 168, 170 may be formed by pressure, such as by a compressive force applied to the top surface of the top compression end cap fitting 144 and / or a compressive force applied to the bottom surface of the bottom compression end cap fitting 156. Such compressive force forces the top and bottom compression end cap fittings 144, 156 toward each other, vertically pinching or crushing the outer and inner cell walls 102, 110 when the photocatalytic reactor cell is oriented vertically (perpendicular to the ground). The top seal 168 and / or the bottom seal 170 may further include one or more gaskets or O-rings, such as elastomeric gaskets and / or O-rings, to provide a relatively airtight (i.e., gas-tight) seal (e.g., a gasket face seal and / or an O-ring seal) between the top compression end cap fitting 144 and / or the bottom compression end cap fitting 156 and the outer cell wall 102 and / or the inner cell wall 110. In some embodiments, a combination of a gasket and an O-ring may be used to provide an airtight seal. In some embodiments, the outer cell wall 102 and the inner cell wall 110 may be of different heights (lengths) to accommodate sealing with a gasket, as opposed to an O-ring. For example, the outer cell wall 102 may be longer than the inner cell wall 110 to aid in mating with the top compression end cap fitting 144 and the bottom compression end cap fitting 156. In such cases, it may be beneficial to use a gasket face seal on the inner cell wall 110 and an O-ring seal on the outer cell wall 102. The top seal 168 and / or bottom seal 170 may include gaskets and / or O-rings located along the ends / edges or sides of the outer cell wall 102 or inner cell wall 110, depending on the configuration of the top compression end cap fitting 144 and / or bottom compression end cap fitting 156. In other embodiments, a gasket or O-ring may not be necessary, with an adequate seal provided by one or more compression forces.Additionally or alternatively, the top and bottom compression end cap fittings 144 and 156, and / or the first tube 104 and second tube 112 may be constructed of one or more materials, such as some plastics, elastomers, or other polymers, which promote a seal when they come into contact.

[0053]

[0086] Figures 33-35 show further details regarding top seal 168 and bottom seal 170 according to some non-limiting embodiments. Each of Figures 33-35 includes reference numbers corresponding to those shown in Figures 5 and 6; the descriptions of the components referred to by those reference numbers are incorporated by reference to Figures 33-35 and will not be repeated here.

[0054]

[0087] FIG. 33 shows details of a top seal 168 for a photocatalytic reactor cell assembly 100 according to an example embodiment. As shown, the top seal 168 is formed by the top compression end cap fitting 144 being compressed against the outer cell wall 102 and the inner cell wall 110 via, for example, tension rods 174. An outer gasket 250 is positioned in a first recess of the top compression end cap fitting 144 between the first peripheral flange 148 and a gasket shoulder 254 (both of which are annular to fit the overall shape of the top compression end cap fitting 144). An inner gasket 252 is positioned in a second recess between the gasket shoulder 254 and the first inner peripheral flange 152. The compressive force applied by the top compression end cap fitting 144 against the outer cell wall 102 and the inner cell wall 110 causes the outer gasket 250 and the inner gasket 252 to form the top seal 168. A similar arrangement (or other arrangements as described below and / or elsewhere) may be provided to implement bottom seal 170.

[0055]

[0088] FIG. 34 shows details of a top seal 168 for a photocatalytic reactor cell assembly 100 according to another exemplary embodiment. As shown, the top seal 168 is formed differently for the inner cell wall 110 and the outer cell wall 102. For the inner cell wall 110, the top seal 168 is formed by the top compression end cap fitting 144 being compressed against the inner cell wall 110 via, for example, a tension rod 174. An inner gasket 252 (which may simply be a gasket material, e.g., an applied coating) is positioned on the top compression end cap fitting 144 (and / or the top edge of the inner cell wall 110), at least where the top compression end cap fitting 144 meets the inner cell wall 110. The compressive force applied to the top compression end cap fitting 144 against the inner cell wall 110 forms the top seal 168 at the inner gasket 252. A similar arrangement (or other arrangements as described below and / or elsewhere) may be provided to implement at least a portion of bottom seal 170.

[0056]

[0089] In the outer cell wall 102, the top seal 168 is formed by a first outer upper O-ring 256 and a second outer upper O-ring 258, respectively, positioned between the outer cell wall 102 and an annular outer O-ring compression sleeve 260. An outer O-ring compression sleeve wedge 262 (trapezoidally shaped) is also positioned between the outer cell wall 102 and the annular O-ring compression sleeve 260, separating the first outer upper O-ring 256 from the second outer upper O-ring 258, as shown. The outer O-ring compression sleeve 260 has a trapezoidal / tapered lip that applies a compressive force to the first outer upper O-ring 256 and the second outer upper O-ring 258 to form a substantially airtight seal, with the O-rings 256 and 258 contacting the outer cell wall 102. Outer O-ring compression sleeve 260 may have a tightening mechanism (e.g., ratchet or compression sleeve fastener 266) and / or may use tapered surfaces (i.e., other than perpendicular to the plane of outer cell wall 102) that form a trapezoidal pressure chamber for O-rings 256 and 258 to apply force to O-rings 256 and 258 as outer O-ring compression sleeve 260 is moved toward top compression end cap fitting 144. In other words, O-rings 256 and 258 may deform slightly toward outer cell wall 102 when the respective tapered surfaces of first perimeter flange 148, outer O-ring compression sleeve 260, and outer O-ring compression sleeve wedge 262 are moved closer to one another. While two O-rings are shown, in some embodiments, the outer portion of top seal 168 may use a single O-ring, three O-rings, or other numbers of O-rings or other sealing members. In the illustrated example, a gap 264 is provided to prevent the outer cell from contacting the top compression end cap fitting 144, thereby allowing the top seal 168 at the inner cell wall 110 to withstand all or substantially all of the compressive load applied between the top compression end cap fitting 144 and the inner cell wall 110 and better form a seal with the inner gasket 252. The gap 264 also reduces the need for tight manufacturing tolerances that would otherwise be required to seal two concentric faces using a gasket (i.e., a face seal).A similar arrangement (or other arrangements as described below and / or elsewhere) may be provided to implement at least a portion of bottom seal 170.

[0057]

[0090] FIG. 35 shows details of a top seal 168 for a photocatalytic reactor cell assembly 100 according to yet another exemplary embodiment. As shown, the top seal 168 is formed using O-rings and outer and inner O-ring compression sleeves. The outer portion of the top seal 168 is similar or identical to that described with respect to FIG. 34 , except that a gap 264 may or may not be included. The inner portion of the top seal 168 is formed by a first inner upper O-ring 272 and a second inner upper O-ring 274, respectively, positioned between the inner cell wall 110 and the annular inner O-ring compression sleeve 268. An inner O-ring compression sleeve wedge 270 (trapezoidally shaped) is also positioned between the inner cell wall 110 and the annular O-ring compression sleeve 270, separating the first inner upper O-ring 272 from the second outer upper O-ring 274, as shown. The inner O-ring compression sleeve 268 has a trapezoidal / tapered lip that applies a compressive force to the first inner upper O-ring 272 and the second outer upper O-ring 274 to form a substantially airtight seal, with the O-rings 272 and 274 contacting the inner cell wall 110. The inner O-ring compression sleeve 268 may have a tightening mechanism (e.g., a ratchet or compression sleeve fastener 266 that draws the inner O-ring compression sleeve 268 closer to the top compression end cap fitting 144) and / or may use a tapered surface (i.e., other than perpendicular to the plane of the inner cell wall 110) that forms a trapezoidal pressure chamber for the O-rings 272 and 274 to apply a force to the O-rings 272 and 274 as the inner O-ring compression sleeve 268 is moved toward the top compression end cap fitting 144. In other words, O-rings 272 and 274 may deform slightly toward inner cell wall 110 when the respective tapered surfaces of first inner circumferential flange 152, inner O-ring compression sleeve 268, and inner O-ring compression sleeve wedge 270 are moved closer to one another. Although two O-rings are shown, in some embodiments, the inner portion of top seal 168 may use a single O-ring, three O-rings, or other numbers of O-rings or other sealing members. A similar arrangement (or other arrangements as described below and / or elsewhere) may be provided to implement at least a portion of bottom seal 170.

[0058]

[0091] 5 and 6, the photocatalytic reactor cell assembly 100 further includes at least one tension rod 174 for applying a compressive force to the top compression end cap fitting 144 and / or the bottom compression end cap fitting 156. For example, as best shown in FIG. 6, the tension rod 174 is coupled to both the top compression end cap fitting 144 and the bottom compression end cap fitting 156 to exert a compressive force sufficient to form the top seal 168 and the bottom seal 170. The tension rod 174 is aligned with the vertical axis 118 around which the outer cell wall 102 and the inner cell wall 110 are concentrically arranged. When two or more tension rods 174 provide the compressive force, the plurality of such tension rods 174 may each be spaced a common distance from and about the vertical axis 118 relative to one another to apply a relatively uniform compressive force around or around the top compression end cap fitting 144 and / or the bottom compression end cap fitting 156. The tension rod(s) 174 may be located inside and / or outside the outer cell wall 102, the inner cell wall 110, and / or the light housing. The tension rod(s) 174 may be constructed of, for example, stainless steel (SS316), an austenitic nickel-chromium-based alloy, a nickel-chromium-iron-molybdenum alloy, or aluminum. Alternatively, or in addition, the tension rod(s) 174 may be constructed of another material. In further embodiments, the tension rod(s) 174 may serve as a mounting structure for attaching the photocatalytic reactor cell 100 to another structure, such as a multi-cell frame forming part of a larger reactor system. In some embodiments, the inner portion 132b and / or the outer portion 132a of the light housing are secured to tension rods.

[0059]

[0092] One or more tension rods 174 may include threads that cooperate with at least one threaded fastener 176 to facilitate tightening of the top compression end cap fitting 144 and / or the bottom compression end cap fitting 156 to the outer cell wall 102 and the inner cell wall 110. The top compression end cap fitting 144 and / or the bottom compression end cap fitting 156 may each include a support 172 through which the tension rod 174 exerts a compressive force. The one or more supports 172 may be threaded or non-threaded to interact with the one or more tension rods 174 and / or the one or more threaded fasteners 176. As an alternative to threads, springs, clamps, air pressure, and / or other mechanisms may be used to apply the compressive force. The one or more supports 172 may be constructed of, for example, stainless steel (SS316), an austenitic nickel-chromium-based alloy, a nickel-chromium-iron-molybdenum alloy, or aluminum. Alternatively, or in addition, the one or more supports 172 may be constructed of another material. In the exemplary embodiment shown in FIGS. 5 and 6 , the supports 172 have a generally conical shape, with the top compression end cap fitting 144 and the bottom compression end cap fitting 156 serving as the respective bases of each conical support 172, and tension rods clamping at the respective apexes of each conical support 172. Alternatively, the one or more supports 172 may have other shapes. In still other embodiments, such as in the case of top compression end cap fittings 144 and / or bottom compression end cap fittings 156 having a disk shape (instead of an annular section shape) or other shape without a central void, tension rods 172 are in direct physical contact with top compression end cap fittings 144 and / or bottom compression end cap fittings 156. As previously mentioned, multiple tension rods 174 may be coupled to each of top compression end cap fittings 144 and bottom compression end cap fittings 156 to exert a collective compressive force sufficient to form top and bottom seals.Potential advantages offered by using one or more tension rods 174 include, among others: (a) improved overall efficiency of the photoreactor due to little to no interference with the photons; (b) reduced exposure to high temperatures compared to other sealing mechanisms, thereby limiting thermal expansion; (c) improved force distribution at the sealing surface compared to multi-bolt flange systems; and (d) concentration of compressive forces between the concentric quartz tubes to limit deformation of the compressive end caps without the use of hardware that penetrates the catalyst bed, thus limiting potential energy loss from the catalyst to hardware that would otherwise penetrate the catalyst bed.

[0060]

[0093] Returning to Figure 4, when the photocatalytic reactor cell assembly 100 is oriented vertically (perpendicular to the ground) with respect to gravity (not shown, but believed to arise from the bottom of Figure 4), the porous base filter 130 is preferably located on the underside (i.e., bottom) of the photocatalyst packed bed 126, closer to the bottom compression end cap fitting 156 than to the top compression end cap fitting 144. The photocatalyst packed bed 126 is vertically positioned in the central portion 122 of the annular volume 120. The upper portion 124 of the annular volume 120 closest to the top compression end cap fitting 144 is devoid of the photocatalyst packed bed 126 to provide sufficient headspace 128 for reactant gas mixing. As at least one gaseous reactant introduced via gas inlet 146 flows through photocatalyst packed bed 126 and at least one resulting product gas exits via gas outlet 158, the emission of photons incident on photocatalyst packed bed 126 (by multiple photon emitters 142a and 142b) activates continuous light-induced gas-phase reactions.

[0061]

[0094] FIG. 7 is an isometric view, and FIG. 8 is an elevational view, illustrating a photocatalytic reactor cell assembly 100 according to another exemplary embodiment. FIGS. 7 and 8 use the same reference numerals as in FIGS. 1-6 to refer to the same or similar features and / or components. Either or both of FIGS. 7 and 8 may omit certain features and / or components from those shown in FIGS. 1-6 (or each other), as appropriate, to facilitate better explanation and understanding. For example, FIGS. 7 and 8 omit at least the outer cooling block 134, the inner cooling block 138, details of the outer and inner portions 132a and 132b of the light housing, the photocatalytic packed bed 126, and the porous base filter 130 (although the described exemplary embodiment may include them). FIGS. 7 and 8 are presented primarily to illustrate variations of the top and bottom end cap fittings 144 and 156 of the photocatalytic reactor cell assembly 100 shown in FIGS. 5 and 6 (i.e., the absence of the support 172 and tension rod 174). Therefore, the photocatalytic reactor cell assembly 100 of FIGS. 7 and 8 is of simpler construction than the photocatalytic reactor cell assembly 100 of FIGS.

[0062]

[0095] 7 and 8 , the photocatalytic reactor cell assembly 100 includes an outer cell wall 102 and an inner cell wall 110, with a top compression end cap fitting 144 and a bottom compression end cap fitting 156 attached to the top and bottom portions of the outer cell wall 102 and the inner cell wall 110, respectively. The top compression end cap fitting 144 includes a reactant gas inlet 146, a first peripheral flange 148 that fits around the top portion 150 of the outer cell wall 102, and a first inner peripheral flange 152 that fits inside the top portion of the inner cell wall 110. Similarly, the bottom compression end cap fitting 156 includes a product gas outlet 158, a second peripheral flange 160 that fits around the bottom portion 162 of the outer cell wall 102, and a second inner peripheral flange (not shown) that fits inside the bottom portion of the inner cell wall 110. In some exemplary embodiments, the top and bottom compression end cap fittings 144, 156 are press-fit into the outer and inner cell walls 102, 110. Alternatively, the top and bottom compression end cap fittings 144, 156 are press-fit into a light housing that surrounds at least a portion (e.g., the outside and inside, respectively) of the outer and inner cell walls 102, 110. Other attachment configurations and / or mechanisms may also be used.

[0063] C. Reactor cell assembly with light housing having outer and inner IR lamps

[0096] FIG. 9 is an isometric view of a reactor cell assembly 100 according to an exemplary embodiment. FIG. 10 is a longitudinal cross-sectional view of a reactor cell assembly 100 according to an exemplary embodiment. FIG. 11 is a cross-sectional view of a reactor cell assembly 100 according to an exemplary embodiment. FIGS. 9-11 may omit certain features and / or components from those shown in the various FIGS. 1-8 (or from each other) as appropriate for better illustration and understanding. For example, FIGS. 9-11 omit at least the outer cooling block 134, the inner cooling block 138, details of the outer and / or inner portions 132a and 132b of the light housing, the photocatalytic packed bed 126, the porous base filter 130, the reactant gas inlet 146, and the product gas outlet 158 ​​(although the exemplary embodiment described may include them). FIGS. 9-11 are presented primarily to illustrate variations of the photocatalytic reactor cell 100 in which an IR lamp serves as a photon emitter and / or heater within the light housing.

[0064]

[0097] As shown in Figures 9-11, reactor cell assembly 100 includes an outer cell wall 102 around which a plurality of photon emitters 142a in the form of IR lamps are circumferentially arranged, serving as the outer portion of an optical housing. Reactor cell assembly 100 further includes an inner cell wall 110 within which a plurality of photon emitters 142b in the form of IR lamps are circumferentially arranged, serving as the inner portion of an optical housing. A top compression end cap fitting 144 and a bottom compression end cap fitting 156 form respective top and bottom seals through which one or more input gaseous reactants and one or more output gaseous products are intended to pass via respective one or more reactant gas inlets and one or more product gas outlets, neither of which are shown in Figures 9-11.

[0065]

[0098] In embodiments in which reactor cell assembly 100 is a photocatalytic reactor cell assembly, annular volume 120 between outer cell wall 102 and inner cell wall 110 may contain a photocatalyst packed bed, where incident light (e.g., in the near-IR spectrum) emitted from multiple photon emitters 142a and 142b activates successive light-induced gas-phase reactions as at least one gaseous reactant flows through the photocatalyst packed bed to generate at least one resultant gaseous product. IR lamps may further supply heat to the photocatalyst packed bed to further catalyze one or more reactions. In alternative embodiments in which reactor cell assembly 100 is a thermocatalytic reactor cell (no photocatalyst in the packed catalyst bed), IR lamps in multiple photon emitters 142a and / or 142b may simply provide infrared radiative heating to the catalyst bed. Because the IR lamps are located on either side of the annular volume 120 between the outer cell wall 102 and the inner cell wall 110, radiant heating is distributed more evenly and directly throughout the catalyst packed bed compared to conventional thermal reactors.

[0066]

[0099] 12 and 13 are elevation and schematic cross-sectional views, respectively, illustrating a single IR lamp 178 that may be used as a photon emitter in multiple photon emitters 142a and / or 142b, according to certain exemplary embodiments. Additionally or alternatively, lamp 178 may be used as a heating element for a photocatalytic reactor cell assembly or a thermal reactor cell assembly, according to exemplary embodiments.

[0067]

[0100] 12 and 13, the IR lamp 178 includes a tungsten filament 180 at the center of a quartz envelope 182 and may have one or more support rings 184 encircling the tungsten filament 180 around the inner periphery of the quartz envelope 182. A portion of the inner surface of the quartz envelope 182 is preferably coated with a reflective coating 186, such as a glazed ceramic coating, to direct the generated infrared radiation toward a target 188 (e.g., a packed photocatalyst bed). For example, the reflective coating 186 may be on a surface of the IR lamp distal from the vertical axis 118 (see, e.g., FIG. 1) in the case of the outer portion 142a of the light housing, or on a surface of the IR lamp proximal to the vertical axis 118 in the case of the inner portion 142b of the light housing. The reflective coating 186 may be selected, for example, to be stable at high temperatures, e.g., up to 1000 degrees Celsius or higher. The amount of the interior surface of the quartz envelope 182 that is coated with the reflective coating 186 can depend on several factors, such as the diameter of the quartz envelope 182, the distance to the target 188, and the width of the target 188. In one exemplary embodiment, half (180 degrees) of the interior circumference of the quartz envelope 182 is coated with the reflective coating 186, as shown in FIG. 13 . This can result in focused radiation being directed at a 120-degree field of view from the IR lamp 178, for example. This focused radiation toward the target 188 provides higher efficiency compared to an IR lamp 178 in which the quartz envelope 182 does not include the reflective coating 186, because radiation that would otherwise be directed away from the target 188 is instead focused toward the target 188. One or more leads 190 can be used to supply current through the tungsten filament 180 to generate the desired infrared radiation.

[0068]

[0101] Infrared radiation is electromagnetic radiation with wavelengths longer than those of visible light. For example, the visible light spectrum can have wavelengths from about 380 nm to about 750 nm, while infrared radiation can have wavelengths from about 750 nm to about 1 mm. Infrared radiation is emitted or absorbed by molecules when they change their rotational / vibrational motion. Absorption of this radiation is generally associated with an increase in the temperature of the molecule. The maximum amount of radiation emitted by an ideal emitter (blackbody) is proportional to the fourth power of its temperature:

number

[0069]

[0102] Infrared heating can be applied to a target by using electric infrared heater technology, in which an electric current is passed through a resistive filament, such as tungsten or nichrome wire, which generates heat and light and emits infrared radiation. The usable range of infrared radiation in industrial applications is 760 μm to about 10,000 nm (10 μm) and is divided into three categories (short wave, high intensity; medium wave, medium intensity; and long wave, low intensity) as shown in Table 1400 in FIG. 14.

[0070]

[0103] Various embodiments of the reactor cell assembly disclosed herein use short-wave IR lamps (e.g., IR lamps 178) to provide heat to the catalyst bed contained in the reactor cell (i.e., the annular volume between the outer and inner cell walls). The IR lamps are mounted within an optical housing (which may simply be a circular group or row of IR lamps themselves) made of an IR-reflective material (e.g., reflective coating 186) to contain substantially all of the emitted radiation within the reactor cell assembly. The short-wave IR lamps generate radiation from a filament (e.g., a tungsten filament 180) at a temperature of 2200°C with a peak wavelength of 1.25 μm. The quartz envelope 182 containing the tungsten filament 180 has excellent high-temperature stability and transmits more than 97% of the infrared radiation (at 677°C) generated by the emitter, as shown in graph 1500 of FIG. 15. These same properties of quartz also favor permeation of the outer and / or inner walls of the reactor cell assembly, allowing for efficient absorption by the catalyst and reactants.

[0071]

[0104] The infrared-transmitting properties of quartz help overcome limitations imposed by its low thermal conductivity, making it a good candidate for constructing the exterior and / or interior walls of a reactor assembly. Furthermore, infrared radiation (including near-infrared radiation) is strongly absorbed by various gas species, such as the reactant gases that may be used in embodiments of the reactor cell assembly disclosed herein. Figure 16 is a graph 1600 illustrating the IR absorption spectra of various gas species (water (vapor), carbon dioxide, carbon monoxide, and methane). Thus, while primary radiation may be centered around a peak wavelength of 1.25 μm, any reflected or scattered radiation may be in the range of about 2 μm to about 10 μm. As shown in Figure 16, this higher wavelength reflected or scattered radiation is more likely to be absorbed by the reactant gases, allowing for efficient radiation utilization by the reactor cell assembly according to various exemplary embodiments.

[0072] D. Reactor cell assembly with optical housing having cooled outer LED and inner IR lamp

[0105] FIG. 17 is an isometric view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIG. 18 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIG. 19 is a cross-sectional view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIGS. 17-19 may omit certain features and / or components from those shown in the various FIGS. 1-11 (or from each other) as appropriate for better illustration and understanding. For example, FIGS. 17-19 omit at least the photocatalytic packed bed 126, the porous base filter 130, the reactant gas inlet 146, and the product gas outlet 158 ​​(although the exemplary embodiment described may include them). FIGS. 17-19 are presented primarily to illustrate variations of the photocatalytic reactor cell 100, in which an LED serves as a photon emitter in the outer portion 132a of the light housing, and an IR lamp serves as a photon emitter and / or heater in the inner portion 132b of the light housing.

[0073]

[0106] As shown in Figures 17-19, reactor cell assembly 100 includes an outer cell wall 102 around which are circumferentially arranged a plurality of photon emitters 142a in the form of LEDs (e.g., several thousand LEDs, each 1-5 mm in diameter) that serve as the outer portion 132a of the light housing. For example, the LEDs may be mounted on an LED circuit board or in other configurations as shown in Figures 1-4 and several other figures herein. Reactor cell assembly 100 further includes an inner cell wall 110 within which are circumferentially arranged a plurality of photon emitters 142b in the form of IR lamps that serve as the inner portion 132b of the light housing. A top compression end cap fitting and a bottom compression end cap fitting (neither of which are shown in Figures 17-19, but which may be similar to those shown in Figures 5-8, for example) form respective top and bottom seals through which only one or more gaseous reactant inputs and one or more gaseous product outputs are intended to pass via respective one or more reactant gas inlets and one or more product gas outlets, for example, similar to those shown in Figures 5-8.

[0074]

[0107] In embodiments in which reactor cell assembly 100 is a photocatalytic reactor cell assembly, annular volume 120 between outer cell wall 102 and inner cell wall 110 may contain a photocatalytic packed bed. Incident light emitted from multiple photon emitters 142 a and 142 b (e.g., in the visible and near-IR spectrum, respectively) activates continuous photoinduced gas-phase reactions as at least one gaseous reactant flows through the photocatalytic packed bed to produce at least one resultant gaseous product. Additionally or alternatively, an IR lamp may supply heat to the photocatalytic packed bed to further catalyze one or more reactions.

[0075]

[0108] Also shown in Figures 17-19 is an outer cooling block 134 including a plurality of outer cooling passages 136. As described with reference to Figures 1-4, the outer cooling block 134 is associated with the outer portion 132a of the optical housing. While the examples of Figures 17-19 also show a plurality of coolant passages 136, the outer cooling block 134 may alternatively or additionally include a hollow-walled reservoir through which a cooling fluid is circulated in whole or in part. For example, the outer cooling block 134 may include an aluminum wall defining a receptacle through which a cooling fluid is passed at a predetermined flow rate. In one exemplary embodiment, the outer cooling block 134 merely functions as a heat sink and does not utilize a cooling fluid. The cooling structure may, for example, maintain a surface on which the photon emitters are mounted at a temperature of 150 degrees Celsius or less.

[0076]

[0109] In addition to the outer cooling block 134, an inner cooling block (not shown) may be included to cool the photon emitter 142b (IR lamp) within the inner portion 132b of the light housing. For example, such an inner cooling block may have a structure and form factor similar to that shown as inner cooling block 138 in FIGS. 20-22, described below, and may use any of several cooling methods, such as fluid cooling, forced air cooling, and / or conduction cooling (e.g., via one or more heat sinks). Also, the cooling block need not itself be in the form of a solid block, but instead may be implemented as two or more separate cooling structures, such as fans, cooling wires, or heat sinks.

[0077] E. Reactor Cell Assembly with Light Housing Having Outer IR Lamp and Cooled Inner LED

[0110] FIG. 20 is an isometric view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIG. 21 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIG. 22 is a cross-sectional view of a photocatalytic reactor cell assembly 100 according to an exemplary embodiment. FIGS. 20-22 may omit certain features and / or components from those shown in the various FIGS. 1-11 (or from each other) as appropriate for better illustration and understanding. For example, FIGS. 20-22 omit at least the photocatalytic packed bed 126, the porous base filter 130, the reactant gas inlet 146, and the product gas outlet 158 ​​(although the exemplary embodiment described may include them). FIGS. 20-22 are presented primarily to illustrate variations of the photocatalytic reactor cell 100, in which an IR lamp serves as a photon emitter and / or heater in the outer portion 132a of the light housing, and an LED serves as a photon emitter in the inner portion 132b of the light housing. Thus, Figures 20-22 show examples where the outer portion of the light housing can act as a heater to heat the annular volume, thereby increasing the reaction rate of a light-induced gas phase reaction.

[0078]

[0111] As shown in Figures 20-22, reactor cell assembly 100 includes an outer cell wall 102 around which are circumferentially arranged a plurality of photon emitters 142a in the form of IR lamps, which serve as the outer portion 132a of the light housing. Reactor cell assembly 100 further includes an inner cell wall 110 within which are circumferentially arranged a plurality of photon emitters 142b in the form of LEDs, which serve as the inner portion 132b of the light housing. For example, the LEDs may be mounted on an LED circuit board or in other configurations as shown in Figures 1-4 and several other figures herein. A top compression end cap fitting and a bottom compression end cap fitting (neither of which are shown in FIGS. 20-22, but which may be similar to those shown in FIGS. 5-8, for example) form respective top and bottom seals through which only one or more gaseous reactant inputs and one or more gaseous product outputs are intended to pass via respective one or more reactant gas inlets and one or more product gas outlets, for example, similar to those shown in FIGS. 5-8.

[0079]

[0112] In embodiments in which reactor cell assembly 100 is a photocatalytic reactor cell assembly, annular volume 120 between outer cell wall 102 and inner cell wall 110 may contain a photocatalytic packed bed. Incident light emitted from multiple photon emitters 142 a and 142 b (e.g., in the near-IR and visible spectrum, respectively) activates continuous photoinduced gas-phase reactions as at least one gaseous reactant flows through the photocatalytic packed bed to produce at least one resultant gaseous product. Additionally or alternatively, an IR lamp may provide heat to the photocatalytic packed bed to further catalyze one or more reactions.

[0080]

[0113] Also shown in FIGS. 20-22 is an inner cooling block 138 including multiple inner cooling passages 140. As described with reference to FIGS. 1-4, the inner cooling block 138 is associated with the inner portion 132b of the light housing. While the examples of FIGS. 20-22 also show multiple coolant passages 140, the inner cooling block 138 may alternatively or additionally include a hollow-walled reservoir through which a cooling fluid is circulated in whole or in part. For example, the inner cooling block 138 may include an aluminum wall defining a receptacle through which a cooling fluid is passed at a predetermined flow rate. In one exemplary embodiment, the inner cooling block 138 merely functions as a heat sink and does not use a cooling fluid. The cooling structure may, for example, maintain a surface on which the photon emitter is mounted at a temperature of 150 degrees Celsius or less. Similarly, in addition to the inner cooling block 138, the outer portion 132a of the light housing may include an outer cooling block (not shown) for cooling the photon emitter 142a (IR lamp). For example, such an outer cooling block may have a structure and form factor similar to that shown as outer cooling block 134 in Figures 17-19 described below, and may use any of several cooling methods, such as fluid cooling, forced air cooling, and / or conduction cooling (e.g., via one or more heat sinks). Also, the cooling block need not be in the form of a solid block itself, but instead may be implemented as two or more separate cooling structures, such as fans, cooling wires, or heat sinks.

[0081] F. Heated Reactor Cell Assembly

[0114] Additionally or alternatively, some exemplary embodiments of the photocatalytic reactor cell assembly 100 include a heater to apply heat to at least the annular volume 120, thereby enhancing the reaction rate of the light-induced gas-phase reaction. Figures 23-32 show examples of such heaters, such as band heaters, recessed annular heaters, recessed helical coil heaters, and recessed IR heaters. Other types of heaters can be used in a manner similar to those shown. For example, one or more cartridge heaters can be used as immersion heaters, potentially providing efficient, low-cost direct immersion heaters.

[0082] G. Reactor cell with outer band heater

[0115] FIG. 23 is an isometric view of a photocatalytic reactor cell assembly 100 with an external band heater 200, according to an exemplary embodiment. FIG. 24 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly 100 with an external band heater 200, according to an exemplary embodiment. FIG. 25 is a cross-sectional view of a photocatalytic reactor cell assembly 100 with an external band heater 200, according to an exemplary embodiment. FIGS. 23-25 ​​may omit certain features and / or components from those shown in various other figures described herein (or from each other) to facilitate better illustration and understanding. For example, FIGS. 23-25 ​​omit at least the photocatalytic packed bed 126, the porous base filter 130, the reactant gas inlet 146, and the product gas outlet 158 ​​(although the exemplary embodiments described may include them). 23-25 ​​are presented primarily to illustrate variations of the photocatalytic reactor cell assembly 100 in which the outer band heaters 200 provide beneficial heating to multiple portions of the photocatalytic reactor cell assembly 100, such as the photocatalytic packed bed 126 (not shown). The outer band heaters 200 provide direct contact with the outer cell walls 102 of the photocatalytic reactor cell assembly 100, allowing for direct heat conduction in conjunction with radiative heat transfer, thus minimizing heat loss.

[0083]

[0116] The outer band heater 200 may take the form of a tubular furnace heater, a ceramic fiber heater, or a heating coil wrapped around the outer cell wall 102. As shown in FIGS. 23-25 ​​, the outer band heater 200 wraps around the outer cell wall 102 so that a first edge of the outer band heater 200 abuts an opposite edge of the outer band heater 200 at a seam 202. A small or non-existent seam 202 may contribute to consistent heating of the photocatalytic reactor cell assembly 100. Of course, wider seams 202 or multiple seams 202 are also possible and may provide other benefits, such as simplified assembly or manufacturing. In some embodiments, the outer band heater 200 is flexible, so assembly may involve wrapping the band heater 200 around the outer cell wall 102 and connecting it end-to-end.

[0084]

[0117] Also shown in FIGS. 23-25 ​​are a top compression end cap fitting 144 with a first peripheral flange 148 and a bottom compression end cap fitting 156 with a second peripheral flange 160. The first and second peripheral flanges 148 and 160 facilitate forming respective top and bottom seals with the outer cell wall 102 to prevent leakage of gaseous reactants or products. Similar flanges or other sealing mechanisms, such as gaskets and / or O-rings, may be used for the inner cell wall 110. Further details regarding the top and bottom seals may be found, for example, with reference to FIGS. 5 and 6. One or more tension rods (not shown) may interface with the top compression socket 204 and the bottom compression socket 206, which may be, for example, threaded openings, to assist in forming compression seals in the top compression end cap fitting 144 and the bottom compression end cap fitting 156. Other arrangements, described elsewhere herein, may be used instead. One or more reactant gas inlets (not shown) and product gas outlets (not shown) respectively provide one or more reactant gases to and remove one or more product gases from the annular volume 120 between the outer cell wall 102 and the inner cell wall 110.

[0085]

[0118] In the exemplary embodiment shown in Figures 23-25, the inner portion 132b of the light housing may be similar or identical to the inner portion 132b shown in Figures 1-4 and 20-22 and includes a photon emitter 142b and an inner cooling block 138 with inner cooling passages 140. However, in contrast to the exemplary embodiments of Figures 1-4 and 20-22, the light housing of Figures 23-25 ​​does not include an outer portion 132a with a photon emitter, but instead includes a band heater 200. Thus, Figures 23-25 ​​illustrate an example in which the outer portion of the light housing acts as a heater to heat the annular volume, thereby increasing the reaction rate of a light-induced gas-phase reaction.

[0086] H. Reactor cell with embedded annular heater

[0119] FIG. 26 is an isometric view illustrating a photocatalytic reactor cell assembly 100 with an annular heater 210, according to an exemplary embodiment. FIG. 27 is a longitudinal cross-sectional view illustrating a photocatalytic reactor cell assembly 100 with an annular heater 210, according to an exemplary embodiment. FIG. 28 is a cross-sectional view illustrating a photocatalytic reactor cell assembly 100 with an annular heater 210, according to an exemplary embodiment. FIGS. 26-28 may omit certain features and / or components from those shown in various other figures described herein (or from each other) to facilitate better illustration and understanding. For example, FIGS. 26-28 omit at least the photocatalytic packed bed 126, the porous base filter 130, the reactant gas inlet 146, and the product gas outlet 158 ​​(although the exemplary embodiments described may include them). 26-28 are presented primarily to illustrate variations of the photocatalytic reactor cell assembly 100 in which an annular heater 210 embedded or immersed in the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 provides beneficial heating to multiple portions of the photocatalytic reactor cell assembly 100, such as the photocatalyst packed bed 126 (not shown). The use of such an embedded / immersed annular heater provides energy directly to the catalyst bed in the annular region, thereby minimizing heat loss by eliminating multiple layers of material between the heat source and the catalyst, compared to external heaters.

[0087]

[0120] With the exception of the annular heater 210, all components shown in FIGS. 26-28 may be similar or identical to those shown in FIGS. 1-3 and are labeled accordingly. Further details regarding such components are described elsewhere herein. In an exemplary embodiment, the annular heater 210 may have a shape (e.g., cylindrical) similar to the first tube 104 and / or the second tube 112. The annular heater 210 may be, for example, a ceramic fiber heater, a substrate with a resistive heating element, or another annular-shaped heater. In some embodiments, the mechanism for providing the heat is less important than the shape of the annular heater 210. An annular heater 210 having a shape that closely resembles the shape of the annular region 120 may advantageously provide consistent heating throughout the annular volume 120. A thicker annular heater 210 may have more thermal mass, but there is a tradeoff in the form of less space available for the photocatalyst packed bed 126 within the annular volume 120. 26-28, the portion of the annular volume 120 occupied by the annular heater 210 is approximately one-third or less, although other portions may be appropriate for some reactor cell geometries, such as a relatively thin or relatively thick annular volume 120.

[0088] I. Reactor cell with embedded helical coil heater

[0121] 29 is an isometric view illustrating a reactor cell assembly 100 with an embedded coil heater 212, according to an example embodiment. To simplify the illustration for better understanding, many components have been omitted from FIG. 29, such as the optical housing (outer and inner portions), end cap fittings, gas inlets and outlets, catalyst bed (e.g., photocatalyst packed bed), porous base filter, cooling block, and any additional heaters other than the coil heater 212.

[0089]

[0122] The reactor cell assembly 100 of Figure 29 includes an outer cell wall 102 concentrically disposed around an inner cell wall 110 to define an annular volume 120 between the outer cell wall 102 and the inner cell wall 110. As shown in Figure 4, the annular volume 120 includes a central portion 122 having a photocatalyst packed bed 126 for catalyzing a light-induced gas-phase reaction. To enhance the reaction rate of the light-induced gas-phase reaction, an embedded coil heater 212 is embedded or immersed in some or all of the central portion 122 of the annular volume 120.

[0090]

[0123] In an exemplary embodiment, the coil heater 212 may be implemented as a helical tube 214 in which a resistance heating wire 216 (e.g., a continuous filament, potentially including a hot section near the catalyst bed and a cold section away from the catalyst bed) is disposed. For example, the coil heater 212 may be an IR coil lamp having a quartz helical tube 214 with a tungsten filament serving as the resistance heating wire 216, similar in configuration to that shown in FIG. 12 , but shaped as a helix that generally conforms to the shape of the annular volume 120. One or more interface tubes 218 (e.g., made of quartz) may interface with first and second ends of the helical tube 214 and receive electrical leads (not shown) to drive current through the resistance heating wire 216. According to some embodiments, the embedded coil heater 212 implemented as a helical quartz IR coil lamp may provide both infrared and radiant heating to the photocatalyst packed bed 126, enhancing the reaction rate of a photoinduced gas-phase reaction. In some embodiments, the use of such coil heaters allows for higher watt densities at higher temperatures for highly endothermic reactions.

[0091] J. Reactor Cell with Embedded IR Heater

[0124] FIG. 30 is an isometric view of a photocatalytic reactor cell assembly 100 with an embedded IR heater 220, according to an exemplary embodiment. FIG. 31 is a longitudinal cross-sectional view of a photocatalytic reactor cell assembly 100 with an embedded IR heater 220, according to an exemplary embodiment. FIG. 32 is a cross-sectional view of a photocatalytic reactor cell assembly 100 with an embedded IR heater 220, according to an exemplary embodiment. FIGS. 30-32 may omit certain features and / or components from those shown in various other figures described herein (or from each other) to facilitate better illustration and understanding. For example, FIGS. 30-32 omit at least the photocatalytic packed bed 126, the porous base filter 130, the reactant gas inlet 146, and the product gas outlet 158 ​​(although the exemplary embodiments described may include them). 30-32 are presented primarily to illustrate variations of the photocatalytic reactor cell assembly 100 in which multiple (e.g., two or more, three or more, four or more, or other numbers) IR heaters 220 are embedded in the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 to provide beneficial heating to multiple portions of the photocatalytic reactor cell assembly 100, such as the photocatalyst packed bed 126 (not shown). The use of embedded IR lamps as heaters allows for direct contact with the catalyst within the annular volume 120, providing both radiative and conductive heat transfer and reducing heat loss. Such a configuration also allows for higher watt densities at higher temperatures, making it highly suitable for highly endothermic reactions such as photocatalytic dry methane reforming (PDMR).

[0092]

[0125] With the exception of the recessed IR heater 220, all components shown in FIGS. 29-31 are similar or identical to those shown in FIGS. 1-3 and are numbered accordingly. Further details regarding such components are described elsewhere herein. In an exemplary embodiment, each of the IR heaters 220 may be similar or identical to the IR lamps described with reference to FIGS. 9-22, particularly FIG. 12. However, the reflective coating 186 shown in FIG. 13 may be omitted from at least the portion of the IR heater 220 adjacent to the photocatalytic bed 126. As shown, the photocatalytic reactor cell assembly 100 includes a plurality of infrared (IR) lamps positioned adjacent to one another in an annular arrangement about a vertical axis between the inner and outer cell walls. The plurality of IR heaters 220, evenly distributed throughout the annular volume 120, advantageously provides consistent heating throughout the annular volume 120. Including relatively more IR heaters 220 may result in more heating, but there is a tradeoff in the form of less space available for the photocatalytic packed bed 126 within the annular volume 120. In the embodiment shown in Figures 30-32, the portion of the annular volume 120 occupied by the IR heaters 220 is approximately one-quarter or less. Other portions may be appropriate for some reactor cell geometries, e.g., IR lamps that are relatively small or large compared to the thickness of the annular volume 120.

[0093] K. Exemplary Reactions and Associated Reaction Conditions

[0126] The various reactor cell assembly embodiments described herein can serve as a platform technology for enabling multiple gas-phase chemical reactions over solid catalysts, such as high-enthalpy reactions and reactions requiring high activation energy by using light energy. For example, the following are some of the reactions and reaction types possible using one or more exemplary embodiments described herein: steam methane reforming; dry methane reforming; partial oxidation of methane; autothermal reforming; ammonia cracking; ammonia synthesis; water-gas shift reaction; reforming of heavier hydrocarbons (e.g., alkylated cyclics, resins, and asphaltenes); Fischer-Tropsch synthesis; methanol synthesis; ethanol synthesis; hydrogenation to make saturates; and dehydrogenation to make ethylene. Other gas-phase reactions and reaction types are also possible using the various embodiments described herein.

[0094]

[0127] Tables 2 and 3 below provide exemplary reaction condition ranges for two exemplary chemical reactions that may be used to carry out chemical reactions in various embodiments of the reactor cells described herein.

[0095]

[0128] Photocatalytic Steam Methane Reforming (multiple embodiments):

[0096] [Table 2]

[0097]

[0129] Photocatalytic decomposition of ammonia (multiple embodiments):

[0098] [Table 3]

[0099]

[0130] Tables 4 and 5 below show exemplary hydrogen production rates by catalyst bed volume for various exemplary reactor cell embodiments described herein.

[0100]

[0131] Photocatalytic Steam Methane Reforming (some embodiments):

[0101] [Table 4]

[0102]

[0132] Photocatalytic decomposition of ammonia (some embodiments):

[0103] [Table 5]

[0104] L. Multiphysics Simulation Modeling and Experimental Results

[0133] COMSOL modeling was used to model the delivery of light to the photocatalytic bed for various light housing designs for an annular-shaped reactor cell assembly. This modeling demonstrated that, in some embodiments, when considering driver losses, electrical and thermal losses in the diode, and light housing losses, the LED-based inner portion of the light housing (i.e., inside the annular portion of the annular-shaped reactor) can deliver approximately 63% of the input electrical energy to the photocatalytic bed. Similarly, when considering driver losses, electrical and thermal losses in the diode, and light housing losses, the modeling demonstrated that the LED-based outer portion of the light housing (i.e., outside the annular portion of the annular-shaped reactor) can deliver approximately 55% of the input electrical energy to the photocatalytic bed. Theoretical calculations were also performed to estimate IR lamp energy delivery efficiency. Based on these theoretical calculations, the exemplary maximum IR energy efficiency achieved using various exemplary embodiments disclosed herein is 75%.

[0105]

[0134] COMSOL ray-tracing simulations were used to determine the intensity of light incident on the photocatalyst packed bed 126 and the efficiency of the light housing (inner and / or outer portions). Each LED (out of thousands of LEDs) acts as a point light source, emitting radiation in the visible spectrum at a certain irradiance. The COMSOL simulation traces each ray through the geometric shapes representing the light housing and other components of the reactor cell assembly 100. The traced rays bounce off surfaces based on Snell's law and Fresnel's equations. Each ray loses some energy with each boundary interaction, eventually dropping below a certain energy threshold and no longer propagating. The photocatalyst packed bed 126 is simulated to be highly absorbing, so if a traced ray reaches the photocatalyst 126, it is completely absorbed due to the COMSOL simulation.

[0106]

[0135] Once the light rays emitted from each individual LED (or other light source) are traced and all representative rays for all LEDs are traced through the light housing geometry, the stored energy (in watts) accumulated at each boundary is divided by the area of ​​the underlying mesh (e.g., a finite element mesh containing triangles). This gives the intensity at each face (e.g., a triangular mesh face segment) that can be used as a heat source for further heat transfer / fluid flow simulations. Mathematically, the resulting light intensity at any triangular mesh face is:

number

[0107]

[0136] Table 6 below shows experimental results and design calculations illustrating the performance of an exemplary embodiment of the reactor cell assembly described herein using photocatalytic steam methane reforming (PSMR) as an exemplary reaction. As can be seen, the conversion percentage was 83% in both the experimental results and the design calculations, which appears to be a significant improvement over typical hydrogen-producing reactors.

[0108] [Table 6] [Example]

[0109] III. Working Examples

[0137] The following numbered examples are embodiments.

[0110]

[0138] 1. A photocatalytic reactor cell assembly, comprising: an outer cell wall including a first tube having a first outer diameter and a first inner diameter; an inner cell wall including a second tube having a second outer diameter and a second inner diameter, the second outer diameter being smaller than the first inner diameter, the outer cell wall and the inner cell wall being concentrically arranged about a vertical axis to define an annular volume between the outer cell wall and the inner cell wall; a top compression end cap fitting having an annular shape and including a reactant gas inlet; a bottom compression end cap fitting having an annular shape and including a product gas outlet, the top compression end cap fitting and the bottom compression end cap fitting forming top and bottom seals with the outer cell wall and the inner cell wall, respectively; a photocatalyst packed bed positioned within the annular volume between the outer cell wall and the inner cell wall, the photocatalyst packed bed including a photocatalyst; and a porous base filler for positioning the photocatalyst packed bed within the annular volume. a porous base filter on a lower surface of the photocatalyst packed bed closer to the bottom compression end cap fitting than to the top compression end cap fitting, the porous base filter having a pore size selected to be gas permeable but impermeable to the photocatalyst in the photocatalyst packed bed; and a light housing including an outer portion and an inner portion, the outer portion being concentrically disposed about a vertical axis outside the outer cell wall and the inner portion being concentrically disposed about the vertical axis inside the inner cell wall, at least one of the outer portion and the inner portion including a circumferential array of photon emitters arranged to uniformly emit photons incident on the photocatalyst packed bed, whereby the photon emissions incident on the photocatalyst packed bed activate a continuous light-induced gas-phase reaction as at least one gaseous reactant introduced through the gas inlet flows through the photocatalyst packed bed and at least one resulting gaseous product exits through the gas outlet.

[0111]

[0139] 2. The photocatalytic reactor cell assembly of Example 1, wherein the first tube is cylindrical.

[0112]

[0140] 3. The photocatalytic reactor cell assembly of example 1 or 2, wherein the first tube has a circular cross section.

[0113]

[0141] 4. The photocatalytic reactor cell assembly of any one of Examples 1 to 3, wherein the second tube is cylindrical.

[0114]

[0142] 5. The photocatalytic reactor cell assembly of any one of Examples 1-4, wherein the second tube has a circular cross section.

[0115]

[0143] 6. The photocatalytic reactor cell assembly of any one of Examples 1 to 5, wherein the first tube and the second tube are cylindrical.

[0116]

[0144] 7. The photocatalytic reactor cell assembly of any one of Examples 1-6, wherein the first tube and the second tube have a circular cross section.

[0117]

[0145] 8. The photocatalytic reactor cell assembly of any one of Examples 1-7, wherein at least a portion of at least one of the outer cell wall and the inner cell wall is constructed of a material that is transparent to photons emitted by the photon emitter.

[0118]

[0146] 9. The photocatalytic reactor cell assembly of any one of Examples 1-8, wherein at least a portion of at least one of the outer cell wall and the inner cell wall is transparent to photons in the visible light spectrum.

[0119]

[0147] 10. The photocatalytic reactor cell assembly of any one of Examples 1-9, wherein at least a portion of at least one of the outer cell wall and the inner cell wall is transparent to photons in the near-IR spectrum.

[0120]

[0148] 11. The photocatalytic reactor cell assembly of any one of Examples 1-10, wherein at least one of the outer cell wall and the inner cell wall comprises a glass tube.

[0121]

[0149] 12. The photocatalytic reactor cell assembly of any one of Examples 1-11, wherein at least one of the outer cell wall and the inner cell wall comprises fused silica glass.

[0122]

[0150] 13. The photocatalytic reactor cell assembly of any one of Examples 1-12, wherein at least one of the outer cell wall and the inner cell wall comprises borosilicate glass.

[0123]

[0151] 14. The photocatalytic reactor cell assembly of any one of Examples 1-13, wherein at least one of the outer cell wall and the inner cell wall comprises a metallic material.

[0124]

[0152] 15. The photocatalytic reactor cell assembly of any one of Examples 1-14, wherein at least a first portion of at least one of the outer cell wall and the inner cell wall is constructed of a material that is transparent to photons emitted by the photon emitter, and at least a second portion of at least one of the outer cell wall and the inner cell wall includes a reflective surface for reflecting the emitted photons into the photocatalyst packed bed.

[0125]

[0153] 16. The photocatalytic reactor cell assembly of any one of Examples 1-15, wherein at least a first portion of at least one of the outer cell wall and the inner cell wall is constructed of a material that is transparent to photons emitted by the photon emitter, and at least a second portion of at least one of the outer cell wall and the inner cell wall includes a scattering surface for scattering the emitted photons into the photocatalyst packed bed.

[0126]

[0154] 17. The photocatalytic reactor cell assembly of any one of Examples 1-16, wherein the photocatalytic packed bed comprises a photocatalyst co-precipitated with a support material.

[0127]

[0155] 18. The photocatalytic reactor cell assembly of any one of Examples 1-17, wherein the photocatalyst comprises an antenna-reactor plasmonic nanoparticle.

[0128]

[0156] 19. The photocatalytic reactor cell assembly of any one of Examples 1-18, wherein the photocatalyst packed bed is positioned vertically in a central portion of the annular volume, and an upper portion of the annular volume nearest the top compression end cap fitting is devoid of a photocatalyst packed bed to provide sufficient headspace for reactant gas mixing.

[0129]

[0157] 20. The photocatalytic reactor cell assembly of any one of Examples 1-19, wherein the top compression end cap fitting and the bottom compression end cap fitting are constructed of stainless steel (SS316).

[0130]

[0158] 21. The photocatalytic reactor cell assembly of any one of Examples 1-19, wherein the top compression end cap fitting and the bottom compression end cap fitting are constructed of an austenitic nickel-chromium based alloy.

[0131]

[0159] 22. The photocatalytic reactor cell assembly of any one of Examples 1-19, wherein the top compression end cap fitting and the bottom compression end cap fitting are constructed of a nickel-chromium-iron-molybdenum alloy.

[0132]

[0160] 23. The photocatalytic reactor cell assembly of any one of Examples 1-19, wherein the top compression end cap fitting and the bottom compression end cap fitting are constructed of aluminum.

[0133]

[0161] 24. A photocatalytic reactor cell assembly according to any one of Examples 1 to 23, wherein the portion of at least one of the top compression end cap fitting and the bottom compression end cap fitting that faces the photocatalyst packed bed is polished to reflect emitted photons into the photocatalyst packed bed.

[0134]

[0162] 25. A photocatalytic reactor cell assembly as described in any one of Examples 1 to 24, wherein the top compression end cap fitting has at least one of a first outer peripheral flange that fits around the top portion of the outer cell wall or a first inner peripheral flange that fits inside the top portion of the inner cell wall.

[0135]

[0163] 26. A photocatalytic reactor cell assembly as described in any one of Examples 1 to 25, wherein the bottom compression end cap fitting has at least one of a second outer peripheral flange that fits around the bottom portion of the outer cell wall or a second inner peripheral flange that fits inside the bottom portion of the inner cell wall.

[0136]

[0164] 27. The photocatalytic reactor cell assembly of any one of Examples 1-26, further comprising a tension rod coupled to each of the top and bottom compression end cap fittings to exert a compressive force sufficient to form the top and bottom seals.

[0137]

[0165] 28. A photocatalytic reactor cell assembly as described in Example 27, wherein the tension rod is positioned so as to be collinear with a vertical axis about which the outer cell wall and the inner cell wall are concentrically arranged, and the tension rod includes threads that cooperate with at least one threaded fastener to facilitate tightening of the top compression end cap fitting and the bottom compression end cap fitting to the outer cell wall and the inner cell wall.

[0138]

[0166] 29. The photocatalytic reactor cell assembly of example 27 or 28, wherein the top compression end cap fitting and the bottom compression end cap fitting each include a support through which the tension rod exerts a compressive force.

[0139]

[0167] 30. The photocatalytic reactor cell assembly of example 29, wherein the tension rods and supports are constructed of aluminum.

[0140]

[0168] 31. The photocatalytic reactor cell assembly of any one of Examples 1-30, further comprising a plurality of tension rods coupled to each of the top and bottom compression end cap fittings to exert a compressive force sufficient to form the top and bottom seals.

[0141]

[0169] 32. The photocatalytic reactor cell assembly of any one of Examples 1-31, further comprising at least one gasket to assist in forming at least one of the top seal or the bottom seal.

[0142]

[0170] 33. The photocatalytic reactor cell assembly of any one of Examples 1-32, further comprising at least one O-ring to assist in forming at least one of the top seal or the bottom seal.

[0143]

[0171] 34. The photocatalytic reactor cell assembly of any one of Examples 1-33, wherein the outer portion of the light housing is cylindrical.

[0144]

[0172] 35. The photocatalytic reactor cell assembly of any one of Examples 1-34, wherein the outer portion of the light housing has a circular cross section.

[0145]

[0173] 36. The photocatalytic reactor cell assembly of any one of Examples 1-35, wherein the inner portion of the light housing is cylindrical.

[0146]

[0174] 37. The photocatalytic reactor cell assembly of any one of Examples 1-36, wherein the interior portion of the light housing has a circular cross section.

[0147]

[0175] 38. The photocatalytic reactor cell assembly of any one of Examples 1-37, wherein the inner light housing portion and the outer light housing portion are cylindrical.

[0148]

[0176] 39. The photocatalytic reactor cell assembly of any one of Examples 1-38, wherein the outer portion of the light housing and the inner portion of the light housing have a circular cross section.

[0149]

[0177] 40. The photocatalytic reactor cell assembly of any one of Examples 1 to 39, wherein at least one of the outer portion of the light housing or the inner portion of the light housing comprises an aluminum frame, and a circumferential array of photon emitters is mounted on the aluminum frame.

[0150]

[0178] 41. A photocatalytic reactor cell assembly according to any one of Examples 1 to 40, wherein at least one of the outer portion of the light housing or the inner portion of the light housing includes a cooling block, a circumferential array of photon emitters mounted on the cooling block, and the cooling block has at least one cooling passage through which a cooling fluid passes.

[0151]

[0179] 42. The photocatalytic reactor cell assembly of any one of Examples 1-41, wherein the cooling block includes a wall defining a receptacle through which a cooling fluid is passed at a predetermined flow rate.

[0152]

[0180] 43. The photocatalytic reactor cell assembly of any one of Examples 1-42, wherein the cooling fluid has a predetermined heat capacity.

[0153]

[0181] 44. A photocatalytic reactor cell assembly described in any one of Examples 1 to 43, wherein the circumferential array of photon emitters includes a plurality of LEDs mounted on at least one of the aluminum walls of the cooling block, whereby cooling fluid passing through the receptacle assists in cooling the plurality of LEDs.

[0154]

[0182] 45. A photocatalytic reactor cell assembly described in any one of Examples 1 to 44, wherein the circumferential array of photon emitters includes a plurality of LEDs, and at least one of the cylindrical shell of the light housing or the inner portion of the light housing includes a cooling block, and the cooling block has at least one of a plurality of coolant passages or a plurality of baffles for passing a cooling fluid through the aluminum cooling block to assist in cooling the plurality of LEDs.

[0155]

[0183] 46. ​​A photocatalytic reactor cell assembly described in any one of Examples 1 to 45, wherein the outer portion includes an outer cooling block and the inner portion includes an inner cooling block, and the outer cooling block and the inner cooling block are configured to assist in cooling the photon emitter.

[0156]

[0184] 47. A photocatalytic reactor cell assembly as described in any one of Examples 1 to 46, wherein the outer portion of the light housing includes a circumferential array of photon emitters arranged on the inner surface of the outer portion to uniformly emit photons incident on the photocatalytic packed bed.

[0157]

[0185] 48. A photocatalytic reactor cell assembly according to any one of Examples 1 to 47, wherein the inner portion of the light housing includes a circumferential array of photon emitters arranged on the outer surface of the inner portion to uniformly emit photons incident on the photocatalytic packed bed.

[0158]

[0186] 49. A photocatalytic reactor cell assembly described in any one of Examples 1 to 48, wherein the outer portion of the light housing includes a first portion of a circumferential array of photon emitters arranged on the inner surface of the outer portion to uniformly emit photons incident on the photocatalytic packed bed, and the inner portion of the light housing includes a second portion of a circumferential array of photon emitters arranged on the outer surface of the inner portion to uniformly emit photons incident on the photocatalytic packed bed.

[0159]

[0187] 50. A photocatalytic reactor cell assembly described in any one of Examples 1 to 49, wherein the outer portion of the light housing is of a clamshell design and includes two sections joined by a hinge to allow installation or removal of the outer portion within the photocatalytic reactor cell assembly.

[0160]

[0188] 51. The photocatalytic reactor cell assembly of any one of Examples 1-50, wherein the inner portion of the light housing is secured to a tension rod.

[0161]

[0189] 52. The photocatalytic reactor cell assembly of any one of Examples 1-51, wherein the outer portion and the inner portion are each connected to at least one of the supports in at least one of the top compression end cap fitting and the bottom compression end cap fitting.

[0162]

[0190] 53. The photocatalytic reactor cell assembly of example 52, wherein the support is constructed of aluminum.

[0163]

[0191] 54. The photocatalytic reactor cell assembly of any one of Examples 1-53, wherein the light housing is fluid-cooled.

[0164]

[0192] 55. The photocatalytic reactor cell assembly of any one of Examples 1-54, wherein the light housing is water-cooled.

[0165]

[0193] 56. A photocatalytic reactor cell assembly described in any one of Examples 1 to 55, wherein the photon emitter is an LED and the light housing includes a cooling system for maintaining the surface on which the photon emitter is attached at a temperature of 150 degrees Celsius or less.

[0166]

[0194] 57. The photocatalytic reactor cell assembly of any one of Examples 1-56, wherein the optical housing includes at least one heat sink.

[0167]

[0195] 58. The photocatalytic reactor cell assembly of example 57, wherein the heat sink is constructed of aluminum.

[0168]

[0196] 59. The photocatalytic reactor cell assembly of any one of Examples 1-58, wherein the optical housing further comprises integrated control electronics for controlling the photon emitter.

[0169]

[0197] 60. The photocatalytic reactor cell assembly of any one of Examples 1-59, wherein both the outer portion and the inner portion have a circular cross-section.

[0170]

[0198] 61. The photocatalytic reactor cell assembly of any one of Examples 1-60, wherein the circumferential array of photon emitters includes a plurality of LED substrates adjacent to one another, each LED substrate including a plurality of LEDs.

[0171]

[0199] 62. The photocatalytic reactor cell assembly of any one of Examples 1-61, wherein the photon emitter is selected to emit photons having sufficient energy and wavelength to activate a photoinduced gas phase reaction.

[0172]

[0200] 63. The photocatalytic reactor cell assembly of any one of Examples 1-62, wherein the photon emitter comprises a light emitting diode (LED) for emitting photons in the visible light spectrum.

[0173]

[0201] 64. The photocatalytic reactor cell assembly of any one of Examples 1-63, wherein the photon emitter comprises an infrared (IR) lamp for emitting photons in the near-IR spectrum.

[0174]

[0202] 65. The photocatalytic reactor cell assembly of any one of Examples 1-64, wherein the photon emitter is selected from the group consisting of a UV lamp, an IR lamp, an arc lamp, or an LED.

[0175]

[0203] 66. The photocatalytic reactor cell assembly of any one of Examples 1 to 65, further comprising a driver for the photon emitter, the driver being selected to operate at a power load of 50% or more to improve driver efficiency.

[0176]

[0204] 67. A photocatalytic reactor cell assembly described in any one of Examples 1 to 66, wherein the circumferential array of photon emitters comprises a plurality of infrared (IR) lamps arranged adjacent to one another in an annular arrangement around the vertical axis.

[0177]

[0205] 68. A photocatalytic reactor cell assembly according to any one of Examples 1 to 67, wherein the outer portion comprises a circumferential array of photon emitters in the form of infrared (IR) lamps arranged annularly about the vertical axis and adjacent to one another outside the outer cell wall, each IR lamp comprising a reflective coating for reflecting IR radiation towards the photocatalytic packed bed, the reflective coating of each IR lamp being on a surface of the IR lamp distal from the vertical axis.

[0178]

[0206] 69. A photocatalytic reactor cell assembly according to any one of Examples 1 to 68, wherein the inner portion comprises a circumferential array of photon emitters in the form of infrared (IR) lamps arranged annularly about the vertical axis and adjacent to one another inside the inner cell wall, each IR lamp comprising a reflective coating for reflecting IR radiation towards the photocatalytic packed bed, the reflective coating of each IR lamp being on a surface of the IR lamp proximal from the vertical axis.

[0179]

[0207] 70. The photocatalytic reactor cell assembly of any one of Examples 1-69, wherein the porous base filter comprises a gas-permeable structural material.

[0180]

[0208] 71. The photocatalytic reactor cell assembly of any one of Examples 1-70, wherein the porous base filter comprises at least one of porous metal, quartz wool, or ceramic.

[0181]

[0209] 72. The photocatalytic reactor cell assembly of any one of Examples 1-71, wherein the porous base filter comprises stainless steel (SS316), an austenitic nickel-chromium-based alloy, or a nickel-chromium-iron-molybdenum alloy.

[0182]

[0210] 73. The photocatalytic reactor cell assembly of any one of Examples 1-72, wherein the porous base filter has an annular shape.

[0183]

[0211] 74. The photocatalytic reactor cell assembly of any one of Examples 1-73, further comprising a heater for heating the annular volume and thereby increasing the reaction rate of the photoinduced gas phase reaction.

[0184]

[0212] 75. The photocatalytic reactor cell assembly of any one of Examples 1-74, wherein the outer portion of the optical housing is a heater that heats the annular volume, thereby increasing the reaction rate of the photoinduced gas phase reaction.

[0185]

[0213] 76. The photocatalytic reactor cell assembly of embodiment 74 or 75, wherein the heater is selected from a tubular furnace heater or a band heater.

[0186]

[0214] 77. The photocatalytic reactor cell assembly of any one of Examples 1-76, further comprising an immersion infrared (IR) coil lamp disposed within a spiral quartz tube within the annular volume.

[0187]

[0215] 78. The photocatalytic reactor cell assembly of any one of Examples 1-77, further comprising a heater embedded in the annular volume, the heater comprising a plurality of infrared (IR) lamps arranged adjacent to one another in an annular arrangement around a vertical axis between the inner and outer cell walls.

[0188]

[0216] 79. The photocatalytic reactor cell assembly of any one of Examples 1-78, further comprising an annular heater immersed in the annular volume.

[0189]

[0217] 80. The photocatalytic reactor cell assembly of any one of Examples 1 to 79, wherein at least one of the first tube or the second tube includes a plurality of cylindrical portions having different diameters, and the cylindrical portions are joined end-to-end via angled connecting portions.

[0190] IV. Conclusion

[0218] The above detailed description, with reference to the accompanying drawings, sets forth various features and operations of the disclosed systems, devices, apparatus, and / or methods. The exemplary embodiments described in this specification and in the drawings are not meant to be limiting, with the true scope being set forth in the following claims. As will be apparent to those skilled in the art, many modifications and variations can be made without departing from the scope thereof. Functionally equivalent systems, devices, apparatus, and / or methods within the scope of the present disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. It will be readily understood that aspects of the present disclosure, as generally described herein and illustrated in the drawings, can be arranged, substituted, combined, separated, and designed in a variety of different ways. Such modifications and variations are intended to fall within the scope of the appended claims. Finally, all publications, patents, and patent applications cited herein are hereby incorporated by reference for all purposes.

Claims

1. 1. A photocatalytic reactor cell assembly comprising: an outer cell wall including a first tube having a first outer diameter and a first inner diameter; an inner cell wall including a second tube having a second outer diameter and a second inner diameter, the second outer diameter being smaller than the first inner diameter, the outer cell wall and the inner cell wall being concentrically disposed about a vertical axis to define an annular volume between the outer cell wall and the inner cell wall, the annular volume having an upper portion and a central portion; a top compression end cap fitting having an annular shape and including a reactant gas inlet; a bottom compression end cap fitting having an annular shape and including a product gas outlet, the top compression end cap fitting and the bottom compression end cap fitting forming top and bottom seals with the outer cell wall and the inner cell wall, respectively; a photocatalyst packed bed positioned within the annular volume between the outer cell wall and the inner cell wall, the photocatalyst packed bed including a photocatalyst; a porous base filter for positioning the photocatalyst packed bed within the annular volume, the porous base filter being on a lower surface of the photocatalyst packed bed closer to the bottom compression end cap fitting than to the top compression end cap fitting, vertically positioning the photocatalyst packed bed in the central portion and providing sufficient headspace in the upper portion for reactant gas mixing, the porous base filter having a pore size selected to be gas permeable but impermeable to the photocatalyst in the photocatalyst packed bed; a light housing including an outer portion and an inner portion, the outer portion being concentrically disposed about the vertical axis outside the outer cell wall, and the inner portion being concentrically disposed about the vertical axis inside the inner cell wall, at least one of the outer portion and the inner portion including a circumferential array of photon emitters arranged to uniformly emit photons incident on the photocatalytic packed bed; whereby the emission of photons incident on the photocatalytic packed bed activates a continuous light-induced gas phase reaction such that at least one gaseous reactant introduced via the gas inlet flows through the photocatalytic packed bed and at least one resultant gaseous product exits via the gas outlet.

2. 10. The photocatalytic reactor cell assembly of claim 1, wherein said first tube and said second tube have a circular cross section.

3. 10. The photocatalytic reactor cell assembly of claim 1, wherein at least a portion of at least one of said outer cell wall and said inner cell wall is constructed of a material that is transparent to said photons emitted by said photon emitter.

4. 10. The photocatalytic reactor cell assembly of claim 1, wherein at least one of the outer cell wall and the inner cell wall comprises fused silica glass, a metallic material, borosilicate glass, or a glass tube.

5. A photocatalytic reactor cell assembly as described in claim 1, wherein at least a first portion of at least one of the outer cell wall and the inner cell wall corresponding to the central portion of the annular volume is constructed of a material that is transparent to the photons emitted by the photon emitter, and at least a second portion of at least one of the outer cell wall and the inner cell wall corresponding to at least the upper portion of the annular volume includes a reflective surface for reflecting the photons emitted by the photon emitter into the photocatalytic packed bed.

6. 10. The photocatalytic reactor cell assembly of claim 1, wherein the photocatalyst is co-precipitated with a support material.

7. A photocatalytic reactor cell assembly as described in claim 1, wherein the upper portion of the annular volume nearest the top compression end cap fitting is devoid of the photocatalytic packed bed.

8. 10. The photocatalytic reactor cell assembly of claim 1, wherein the top compression end cap fitting and the bottom compression end cap fitting are constructed of stainless steel (SS316), an austenitic nickel-chromium base alloy, a nickel-chromium-iron-molybdenum alloy, or aluminum.

9. 2. The photocatalytic reactor cell assembly of claim 1, further comprising a tension rod located inside the inner cell wall and coupled to each of the top compression end cap fitting and the bottom compression end cap fitting to exert a compressive force sufficient to form the top seal and the bottom seal.

10. 10. The photocatalytic reactor cell assembly of claim 1, further comprising at least one gasket to assist in forming at least one of said top seal or said bottom seal.

11. 10. The photocatalytic reactor cell assembly of claim 1, further comprising at least one O-ring to assist in forming at least one of said top seal or said bottom seal.

12. 10. The photocatalytic reactor cell assembly of claim 1, wherein said outer portion of said light housing and said inner portion of said light housing have a circular cross section.

13. 13. A photocatalytic reactor cell assembly as described in any one of claims 1 to 12, wherein at least one of the outer portion of the light housing or the inner portion of the light housing includes a cooling block on which the circumferential array of photon emitters is mounted, the cooling block having at least one cooling passage through which a cooling fluid passes.

14. 14. The photocatalytic reactor cell assembly of claim 13, wherein the cooling block includes an aluminum wall defining a receptacle through which the cooling fluid is passed at a predetermined flow rate.

15. A photocatalytic reactor cell assembly as described in claim 1, wherein the outer portion of the optical housing includes an outer cooling block and the inner portion of the optical housing includes an inner cooling block, the outer cooling block and the inner cooling block being configured to assist in cooling the photon emitter.

16. 2. The photocatalytic reactor cell assembly of claim 1, wherein the outer portion of the light housing includes a circumferential array of photon emitters disposed on an inner surface of the outer portion to uniformly emit photons incident on the photocatalytic packed bed.

17. 2. The photocatalytic reactor cell assembly of claim 1, wherein the inner portion of the light housing includes a circumferential array of photon emitters positioned on an outer surface of the inner portion to uniformly emit photons incident on the photocatalytic packed bed.

18. 2. The photocatalytic reactor cell assembly of claim 1, wherein the outer portion of the light housing includes a first portion of a circumferential array of photon emitters arranged on an inner surface of the outer portion to uniformly emit photons incident on the photocatalytic packed bed, and the inner portion of the light housing includes a second portion of a circumferential array of photon emitters arranged on an outer surface of the inner portion to uniformly emit photons incident on the photocatalytic packed bed.

19. A photocatalytic reactor cell assembly as described in claim 1, wherein the outer portion of the optical housing and the inner portion of the optical housing are each connected to at least one support in at least one of the top compression end cap fitting and the bottom compression end cap fitting.

20. 10. The photocatalytic reactor cell assembly of claim 1, wherein said optical housing further includes integrated control electronics for controlling said photon emitter.

21. 10. The photocatalytic reactor cell assembly of claim 1, wherein said photon emitter is selected to emit photons having sufficient energy and wavelength to activate said photoinduced gas phase reaction.

22. 10. The photocatalytic reactor cell assembly of claim 1, wherein said photon emitter is selected from the group consisting of a UV lamp, an IR lamp, an arc lamp, or an LED.

23. 10. The photocatalytic reactor cell assembly of claim 1, wherein said circumferential array of photon emitters comprises a plurality of infrared (IR) lamps arranged adjacent one another in an annular configuration about said vertical axis.

24. A photocatalytic reactor cell assembly as described in claim 1, wherein the outer portion of the optical housing includes a circumferential array of photon emitters in the form of infrared (IR) lamps arranged annularly around the vertical axis and adjacent to one another outside the outer cell wall, each IR lamp including a reflective coating for reflecting IR radiation toward the photocatalytic packed bed, the reflective coating of each IR lamp being on a surface of the IR lamp distal from the vertical axis.

25. A photocatalytic reactor cell assembly as described in claim 1, wherein the inner portion of the optical housing includes a circumferential array of photon emitters in the form of infrared (IR) lamps arranged annularly around the vertical axis and adjacent to one another inside the inner cell wall, each IR lamp including a reflective coating for reflecting IR radiation toward the photocatalytic packed bed, the reflective coating of each IR lamp being on a surface of the IR lamp proximal to the vertical axis.

26. 10. The photocatalytic reactor cell assembly of claim 1, wherein said porous base filter comprises a gas-permeable structural material.

27. 10. The photocatalytic reactor cell assembly of claim 1, further comprising an immersion infrared (IR) coil lamp disposed within a spiral quartz tube within said annular volume.

28. 2. The photocatalytic reactor cell assembly of claim 1, further comprising a heater embedded in the annular volume, the heater comprising a plurality of infrared (IR) lamps arranged adjacent to one another in an annular arrangement around the vertical axis between the inner cell wall and the outer cell wall.

Images