Patent Application
20240316518
This disclosure relates to the field of industrial chemical production, and, in particular, to the design and construction of reactor cells for photocatalysis of gaseous species for industrial chemical production.
Photocatalysis, as used herein, refers to irradiating a chemical process with photons to accelerate the rate of chemical conversion of reactants to selectively form a desired product. Incident photons of sufficient energy and wavelength activate photo-induced reactions by unlocking reaction mechanisms that otherwise may not be accessible via thermally activated processes. Recent developments in photocatalysis include the use of plasmonic nanoparticles that exhibit strong interactions with visible light due to the excitation of electronic oscillations. See, e.g., the following, the contents of each of which is incorporated by reference herein: (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., “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., “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, 5 Oct. 2018, 69-72, https://doi.org/10.1126/science.aat6967. These plasmonic nanoparticles offer the possibility of increased efficiency due to increased selectivity to desired products at reduced energy consumption. While plasmonic nanoparticles have attracted significant interest in academia for various chemical transformations, known industrial applications are limited to wastewater treatment and purification processes, all of which are 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, the entirety of which is incorporated by reference herein.
Conversely, thermal catalysis is responsible for the production of approximately 85% of all industry-produced chemicals. However, thermal catalysis typically requires relatively extreme reaction conditions, including high temperatures and pressures, resulting in reduced process efficiency and a large carbon footprint.
Combining photocatalysis with thermal catalysis in a cooperative manner offers the possibility of increasing product selectivity while reducing the energy requirement for the process. However, considerable engineering challenges accompany combining photon sources and heaters into a single modular system, and therefore, photothermal catalytic systems have been studied predominantly in academia. See, e.g., Nair et al., “Thermo-Photocatalysis: Environmental and Energy Applications,” ChemSusChem, 2019, 12 (10), 2098-2116, https://doi.org/10.1002/cssc.201900175, the entirety of which is incorporated by reference herein.
Needed are improved reactor designs for photocatalysis and photothermal catalytic systems for industrial chemical production.
One embodiment set forth herein is directed to a photocatalytic reactor cell assembly that includes an outer cell wall and an inner cell wall. The outer cell wall and the inner cell wall are arranged concentrically about a vertical axis to define an annular volume between the outer cell wall and the inner cell wall. A top endcap fitting having a reactant gas inlet and a bottom endcap fitting having a product gas outlet respectively form a top seal and a bottom seal with the outer cell wall and the inner cell wall. A photocatalyst packed bed is positioned in the annular volume between the outer cell wall and the inner cell wall by a porous base filter. A light housing includes photon emitters arranged to uniformly emit photons incident on the photocatalyst packed bed in order to activate continuous photo-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 resultant gaseous product exits via the gas outlet.
One or more cooling structures and/or mechanisms may be provided to provide cooling to the photon emitters and/or to portions of the light housing on which the photon emitters are mounted.
One or more heaters may be provided to heat the photocatalyst packed bed, to increase the reaction rate of photo-induced gas-phase reactions.
These, as well as other embodiments, aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, this summary and other descriptions and figures provided herein are intended to illustrate embodiments by way of example only and, as such, numerous variations are possible. For instance, structural elements and process steps can be rearranged, combined, distributed, eliminated, or otherwise changed, while remaining within the scope of the embodiments as claimed.
The accompanying drawings are included to provide a further understanding of the systems, apparatus, devices, and/or methods of the disclosure, and are incorporated in 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 illustrated as simplistic representations to promote comprehension. The drawings illustrate one or more embodiments of the disclosure, and together with the description, serve to explain the principles and operation of the disclosure.
Example systems, apparatus, devices, 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 an “example” is not necessarily to be construed as preferred or advantageous over other embodiments or features unless stated as such. Thus, other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein. The aspects described herein are not limited to specific embodiments, apparatus, or configurations, and as such can, of course, vary. It should be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and unless specifically defined herein, is not intended to be limiting.
Throughout this specification, unless the context requires otherwise, the words “comprise” and “include” and variations (e.g., “comprises,” “comprising,” “includes,” “including,” “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.
Further, unless context suggests otherwise, the features illustrated in each of the figures may be used in combination with one another. Thus, the figures should be generally viewed as component aspects of one or more overall embodiments, with the understanding that not all illustrated features are necessary for each embodiment.
As used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
Ranges can 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.
Any enumeration of elements, blocks, or steps in this specification or the claims is for purposes of clarity. Thus, such enumeration should not be interpreted to require or imply that these elements, blocks, or steps adhere to a particular arrangement or are carried out in a particular order.
Effective, functional photocatalytic reactors are designed such that catalyst contacted with the reactant is uniformly illuminated by a photon source, thus driving the chemical reaction. Irradiation of light could be achieved by using natural (e.g., solar) or artificial sources of light (e.g., IR lamps, UV lamps, arc lamps, or light emitting diodes (LEDs). Typical reactor configurations include slurry reactors, annular reactors, immersion reactors and optical fiber/tube reactors. See, e.g., Van Gerven et al., “A Review of Intensification of Photocatalytic Processes,” Chem. Eng. Process. Process Intensif., 2007, 46 (9 SPEC. ISS.), 781-789, https://doi.org/10.1016/j.cep.2007.05.012, the entirety of which is incorporated by reference herein. Challenges to process intensification of these reactors mainly arise from photon and mass transfer limitations. Research into photocatalytic reactors for the conversion of gaseous species is still in its infancy, and the present applicants are not aware of any reported examples of a successful scale-up of a laboratory set-up to an industrially relevant scale. Difficulties in reactor design, material selection, and an incomplete understanding of the critical parameters that are important to reactor design have hampered past development efforts. See, e.g., de Lasa et al., “Photocatalytic Reaction Engineering,” Springer, Boston, M A, 2005, https://doi.org/i0.1007/0-387-27591-6.
Several large-scale photocatalytic reactors have been proposed, and of these designs, slurry reactors, annular reactors, immersion reactors, and optical tube reactors have been tested in the area of wastewater treatment, for liquid state reactions only. See, e.g., de Lasa et al., “Photocatalytic Reaction Engineering,” Springer, Boston, M A, 2005. The light source in such reactors is oriented such that it illuminates the longitudinal axis of the reactors to drive the photocatalytic treatment of wastewater. The catalyst in the reactor is either fluidized by the wastewater or immobilized by 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 in the reactor to create turbulent fluid flow. See, e.g., U.S. Patent Application Publication No. US20130008857A1. More recently, photocatalytic reactors are being used for the removal of volatile organic components as part of air purification modules. See, e.g., U.S. Patent Application Publication No. US20210023255A1. These reactor designs incorporate “fins” or directional blades to improve mass transfer and contacting of the air with the coated photocatalyst.
Implementation of these processes at a larger scale than that studied in research and development settings has been stymied for a variety of reasons. Photocatalytic reactor development has not had the decades of experience associated with thermal catalytic reactors. A sound understanding of the fundamental processes underlying thermal catalytic reactors simplifies the scaleup of a lab-scale thermal catalytic reactor process to the pilot scale and beyond. Thermal catalytic reactors also benefit from proven numerical and kinetic modeling. Conversely, investigations into photocatalytic and photo-thermal catalytic processes have instead focused on clarifying product formation and reaction kinetics, as well as obtaining a mechanistic understanding of the underlying chemistry. The inclusion of photons in photocatalysis causes significant deviations in reactor performance from traditional thermal catalytic reactors. Added complexities include the selection of suitable light sources and reactor geometries (which affects photon behavior and catalytic performance of the process). These unknowns add significant variability to scale-up and process intensification. See, e.g., 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 by reference herein.
Other complexities have contributed to the relatively slow development of photocatalytic reactor designs. See, e.g., 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, the entirety of which is incorporated by reference herein. One such consideration includes the choice of material for reactor cell construction, as photocatalytic processes require transparent windows for light or photons to irradiate the catalyst. Reactor geometries should also be optimized for photon transport such that light losses are minimized and photon flux is concentrated toward the catalyst bed. A photocatalytic reactor cell design should also be able to facilitate gas-solid mixing and transport characteristics to promote optimal catalytic performance. Fabrication of stainless steel and glass-based pilot-scale photocatalytic reactors within design specifications is an engineering challenge that has been an obstacle to further development. Inclusion of reflective materials, control electronics for photon sources, and auxiliary processes to support photocatalytic reactor functions have added considerable complexity to the development of photocatalytic reactors.
To address some of the shortcomings of prior photocatalytic reactor cells, disclosed herein are various embodiments of an improved reactor cell assembly for photocatalysis of gaseous species for industrial chemical production. The disclosed reactor cell embodiments include example reactor cells capable of performing chemical reactions with gaseous feed using incident photons (i.e., light) over a packed bed of photocatalyst placed in the annulus of a reactor cell having outer and inner cell walls. In some example embodiments, one or both of the outer and inner cell walls are transparent. Other reactor cell embodiments are also described herein.
Example embodiments set forth herein are generally directed to a photocatalytic reactor cell that is annular in nature, with a nanoparticle photocatalyst packed bed. The annular region may be made of materials transparent in the visible and near IR region. The gaseous reactants flow through the packed photocatalyst bed similar to as in a plug-flow reactor, allowing for continuous reaction and generation of the desired product. The energy to the photocatalyst may be provided on one or both sides (i.e., exterior and/or interior) of the annular region via a light housing having many photon emitters, such as Light Emitting Diodes (LEDs) or IR lamps, mounted on or serving as portions of the light housing, for example. The specific geometry and use of transparent or reflective or scattering materials allows for an efficient way of transmitting light energy to the photocatalyst, to promote efficient chemical reactions. In some embodiments, the light housing may include a cooling assembly to assist in cooling the photon emitters and/or surfaces on which the photon emitters are mounted. In some other embodiments, one or more heaters may be included to increase the photocatalytic reaction rate.
Some embodiments set forth herein allow for reduced dependency on fossil fuels and reduced carbon emissions. For example, embodiments having LEDs as photon emitters may utilize electricity for activation of the LEDs. Such electricity may be generated using renewable resources, such as solar-, hydro-, or wind-generated power. As a result, environmental benefits may be realized for industrial chemical reactions that have conventionally been performed via thermal catalysis using heat energy generated by burning of fossil fuels.
The chemical reactions that can be performed in various embodiments of the reactor cells described herein conventionally require very high temperatures due to high enthalpy of reaction. Conventional thermal catalytic reactors are typically made of relatively expensive materials that can sustain such high temperatures. In addition, conventional thermal catalytic reactors are typically imparted with heat energy in an inefficient and environmentally unfriendly manner via burning of fossil fuels. Conversely, various reactor cell embodiments described herein can assist in performing these same chemical reactions in the presence of visible light at much lower temperatures than required for conventional thermal catalytic reactors. This enables the use of relatively inexpensive materials, such as glass or aluminum, for the construction of the reactor. Additionally, the accompanying lower operating temperatures may prolong the lifespan of reactor components for the example photocatalytic reactors described herein.
The various reactor cell assembly embodiments set forth herein may serve as a platform technology allowing for multiple gas-phase chemical reactions requiring high enthalpy of reaction and high activation energy via the use of light energy. For example, the following is a non-exclusive list of reactions and reaction types possible using one or more example embodiments set forth herein:
A. Reactor Cell Assembly having Cooled Outer and Inner LED Light Housing
As illustrated, the photocatalytic reactor cell assembly 100 includes an outer cell wall 102 comprising 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 comprising 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 arranged concentrically about a vertical axis 118 to define an annular volume 120 between the outer cell wall 102 and the inner cell wall 110.
In the example of
For the embodiment illustrated in
As shown in
The 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 may include a photocatalyst co-precipitated with a support material. The photocatalyst may comprise antenna-reactor plasmonic nanoparticles, for example. Various antenna-reactor catalysts developed by Rice University are described in U.S. Pat. No. 10,766,024 (incorporated by reference herein) and can effectively utilize light energy to perform 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 velocity, resulting in a high hydrogen production rate per unit volume of catalyst bed. Depending on the type of chemical reaction to be performed, an appropriate antenna-reactor catalyst can be matched with correspondingly appropriate LED diodes to efficiently activate the photocatalyst, thereby resulting in high reaction rates. For example, in the case of Photocatalytic Steam Methane Reformation (PSMR), a high reaction rate equivalent to 270 micromoles/g/s has been achieved using an appropriate photocatalyst in reactor cell embodiments described herein.
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 middle portion 122 of the annular volume 120 illustrated in
The use of reflective and/or scattering surfaces may help to minimize heat losses from the reactor cell assembly 100. Based on multiphysics simulation modeling using COMSOL, it has been determined that heat losses may be minimized using one or more of the following principles: (a) utilizing appropriate materials at different parts of the reactor to minimize or advantageously re-use the radiative heat transferred from the energized catalyst bed to other parts of the reactor; (b) utilizing appropriate insulation materials at different parts of the reactor; (c) minimizing the use of metal in the reactor and instead using materials with lower thermal conductivity (e.g., glass or quartz), thus increasing the resistance to heat transfer from the photocatalytic reactor cell assembly 100 to the environment. The reactor cell embodiments described herein operate at much lower temperatures then conventional thermal reactors, allowing for the use of materials such as quartz, aluminum, and ceramics. This may reduce the loss of energy from reactor cell assembly 100, thus potentially increasing energy efficiency compared to conventional reactors.
As illustrated in
Table 1, below, sets forth example physical dimensions for various example reactor cell embodiments set forth herein:
The photocatalytic reactor cell 100 illustrated in
In some example embodiments, the outer portion 132a of the light housing is of an outwardly opening clamshell design and comprises two (or more) sections coupled by a hinge (not shown) to allow for installation or removal of the outer portion 132a in the photocatalytic reactor cell assembly 100. Similarly, the inner portion 132b of the light housing may be of an inwardly opening clamshell design comprising two (or more) sections coupled by a hinge (not shown) to allow for installation or removal of the inner portion 132b in the photocatalytic reactor cell assembly 100.
As illustrated in
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 being cylindrically shaped on both its interior and exterior, the outer portion 132a may be cylindrical on its interior, but surrounded by other equipment, components, and/or materials, such as heat management and/or control equipment, components, and/or materials, giving 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 generally hollow as shown in
Some or all of the photon emitters in the circumferential array of photon emitters on the outer portion 132a and/or the inner portion 132b may be LEDs mounted on LED circuit boards or in other configurations, as is illustrated in
The photocatalytic reactor cell assembly 100 may also include integrated control electronics to control the photon emitters, as well as drivers to drive the photon emitters. For example, LED drivers may be selected to operate at 50% or greater power load during operation of the photocatalytic reactor cell assembly 100, in order to improve driver efficiency. A system of several or many photocatalytic reactor cell assemblies 100 may share at least some common electronics, for example. In addition to operating the LED drivers at a 50% or greater power load during operation, another design consideration for efficient light delivery is to alter operating current to allow the LEDs to operate at maximum efficiency. In addition, the LEDS themselves may be chosen to have high photon efficiency in the same spectrum range (e.g., same visible spectrum range) as the photocatalyst. Diodes of different semiconductor materials are available with different specified electrical-to-photon energy efficiency. By choosing diodes with high photon efficiency in the same range as the photocatalyst, absorption of light by the catalyst can be increased.
The outer portion 132a of the light housing may be attached (e.g., via epoxy, adhesive, or mechanical fasteners) to the outer cell wall 102. The inner portion 132b of the light housing may be attached (e.g., via epoxy, adhesive, or mechanical fasteners) to the inner cell wall 110. Alternatively, the outer portion 132a and/or the inner portion 132b of the light housing may simply be positioned adjacent and in close proximity to the outer cell wall 102 and the inner cell wall 110, respectively, without being physically attached. As yet another alternative, a respective separation distance between (a) the outer portion 132a and/or the inner portion 132b of the light housing and (b) the outer cell wall 102 and the inner cell wall 110 may be chosen to realize desired lighting geometries. For example, either or both of the outer portion 132a and the inner portion 132b may have a small separation between itself and the outer cell wall 102 and the inner cell wall 110, respectively. As another example, either the outer portion 132a or the inner portion 132b may have a small separation to the outer cell wall 102 or the inner cell wall 110, while the other has a relatively larger separation. Separation 208 is illustrated as an example 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 upon which the circumferential array of photon emitters is mounted, and which may or may not be attached directly to the outer cell wall 102 and/or the inner cell wall 110. For example, such 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 for the outer portion 132a of the light housing and another frame or structure for the inner portion 132b of the light housing. In some embodiments, the mounting frame(s) or structure(s) for the circumferential array(s) of photon emitters may serve as cooling structures, in the form of cooling jackets, heat sinks, or other heat-dissipation mechanisms.
The embodiment illustrated in
Generally, the outer portion 132a of the light housing may comprise an outer cooling block 134 and the inner portion 132b of the light housing may comprise 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, the circumferential array of photon emitters may include a plurality of LEDs (on LED boards) mounted on at least one of the walls (e.g., aluminum walls) of the cooling block(s) 134 and/or 138, so that cooling fluid passing through each cooling block's coolant passage(s) and/or receptacle(s) assists in cooling the plurality of LED boards. Coolant may be introduced to and removed from the cooling block(s) 134 and/or 138 via one or more coolant lines interfaced with the outer coolant passages 136 and/or the inner coolant passages 140. Such coolant lines (not illustrated) may recirculate/recycle coolant (after appropriate heat removal or dissipation) and/or may introduce new coolant and remove old coolant, with no recirculation.
The cooling fluid utilized in the outer cooling block 135 and/or the inner cooling block 138 may be chosen to have a predetermined heat capacity. The cooling fluid (or coolant) may be selected from the following non-exhaustive list, for example: ammonia, synthetic hydrocarbons of aromatic chemistry (i.e., diethyl benzene [DEB], dibenzyl toluene, diaryl alkyl, partially hydrogenated terphenyl), silicate-esters, aliphatic hydrocarbons of paraffinic and iso-paraffinic type, dimethyl- and methyl phenyl-poly (siloxane), fluorinated compounds such as perfluorocarbons (i.e., FC-72, FC-77) hydrofluoroethers (HFE) and perfluorocarbon ethers (PFE), ethylene glycol, propylene glycol, methanol/water, ethanol/water, calcium chloride solution (e.g., 29% by wt.), aqueous solutions of potassium formate and acetate salts, and liquid metals (e.g., Ga—In—Sn).
As shown, the photocatalytic reactor cell assembly 100 includes a top compression endcap fitting 144 having an annular shape. The top compression endcap fitting 144 includes one or more (e.g., four) reactant gas inlets 146 for receiving a continuous flow of input gaseous reactant feedstock, which may include one or more constituent reactant gases. The top compression endcap fitting 144 may have a first outer circumferential flange 148 to fit around a top portion 150 of the outer cell wall 102, a first inner circumferential flange 152 to fit inside or outside a top portion 154 of the inner cell wall 110, or both the first outer circumferential flange 148 and first inner circumferential flange 152. While the above discussion and FIGS. 5 and 6 illustrate a cylindrical (annular) shape for the top compression endcap fitting 144, a circular shape may alternatively be used. As yet another alternative, non-cylindrical (non-annular) shapes may be suitable for a first tube 104 having a non-circular cross-section. For example, the top compression endcap fitting 144 may have a cross section that matched a regular polygonal cross section of the first tube 104. In addition, either or both of the first outer circumferential flange 148 and the first inner circumferential flange 152 may be omitted, in some embodiments.
Also as shown, the photocatalytic reactor cell assembly 100 includes a bottom compression endcap fitting 156 having an annular shape. The bottom compression endcap fitting 156 has one or more (e.g., four) product gas outlets 158 for outputting a continuous flow of gaseous product, which may include one or more constituent product gases. The bottom compression endcap fitting 156 has a second outer circumferential flange 160 to fit around a bottom portion 162 of the outer cell wall 102, a second inner circumferential flange 164 to fit inside or outside a bottom portion 166 of the inner cell wall 110, or both the second outer circumferential flange 160 and the second inner circumferential flange 164. While the above discussion and
The top compression endcap fitting 144 and the bottom compression endcap fitting 156 may be constructed of stainless steel (SS316), an austenitic nickel-chromium-based alloy, a nickel-chromium-iron-molybdenum alloy, or aluminum, for example. The top compression endcap fitting 144 and the bottom compression endcap fitting 156 alternatively or additionally may be constructed of other materials, such as those having a low coefficient of thermal expansion. Moreover, a portion (i.e., an inside-facing portion) of at least one of the top compression endcap fitting 144 and the bottom compression endcap fitting 156 facing the photocatalyst packed bed 126 may be polished to reflect emitted photons into the photocatalyst packed bed 126. Alternatively, a reflective coating (not shown) may be deposited or adhered to the top compression endcap fitting 144 and/or the bottom compression endcap fitting 156 facing the photocatalyst packed bed 126 to accomplish a similar purpose.
The top compression endcap fitting 144 and the bottom compression endcap fitting 156 respectively form a top seal 168 and a bottom seal 170 with the outer cell wall 102 and the inner cell wall 110. Either or both of the top seal 168 and the bottom seal 170 may be formed via pressure, such as by a compression force applied to a top surface of the top compression endcap fitting 144 and/or a compression force applied to a bottom surface of the bottom compression endcap fitting 156. Such a compression force presses the top and bottom compression endcap fittings 144 and 156 toward each other, vertically sandwiching or squeezing the outer cell wall 102 and the inner cell wall 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 an elastomeric gasket and/or O-ring, to create a relatively gas-tight (i.e., gas-impermeable) seal (e.g., a gasket face seal and/or an O-ring seal) between the top compression endcap fitting 144 and/or the bottom compression endcap fitting 156 and the outer cell wall 102 and/or the inner cell wall 110. A combination of gaskets and O-rings may be used to create gas-tight seals, in some embodiments. 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 inner cell wall 102 may be longer than the outer cell wall 110 to assist in coupling with the top compression endcap fitting 144 and the bottom compression endcap fitting 156. In such a case, it may be beneficial to use a gasket face seal for the inner cell wall 110 and an O-ring seal for the outer cell wall 102. The top seal 168 and/or the bottom seal 170 may include a gasket and/or O-ring located at an end/edge of the outer cell wall 102 or inner cell wall 110 or along a side of the inner cell wall 102 or inner cell wall 110, depending on the configuration of the top compression endcap fitting 144 and/or the bottom compression endcap fitting 156. In other embodiments, no gaskets or O-rings may be necessary, with adequate seals being created through compression force(s). Additionally or alternatively, the top and bottom compression endcap fittings 144 and 156 and/or the first tube 104 and second tube 112 may be constructed of material(s), such as certain plastics, elastomers, or other polymers, that promote a seal when interfaced.
For 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 each positioned between the outer cell wall 102 and an annular outer O-ring compression sleeve 260. An outer O-ring compression sleeve wedge 262 (trapezoidal-shaped) is also positioned between the outer cell wall 102 and an annular O-ring compression sleeve 260 and separates the first outer upper O-ring 256 from the second outer upper O-ring 258, as illustrated. The outer O-ring compression sleeve 260 has a trapezoidal/tapered lip to apply a compressive force to the first outer upper O-ring 256 and the second outer upper O-ring 258 to form a substantially gas-tight seal where the O-rings 256 and 258 contact the outer cell wall 102. The outer O-ring compression sleeve 260 may have a tightening mechanism (e.g., a ratchet or a compression sleeve fastener 266) and/or may utilize tapered surfaces (i.e., other than normal to the surface of the outer cell wall 102) forming a trapezoidal compression chamber for the O-rings 256 and 258) to apply a force to the O-rings 256 and 258 as the outer O-ring compression sleeve 260 is moved toward the top compression endcap fitting 144. In other words, the O-rings 256 and 256 may deform slightly toward the outer cell wall 102 as the tapered surfaces on the first outer circumferential flange 148, the outer O-ring compression sleeve 260, and the 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 the top seal 168 may utilize a single O-ring, three O-rings, or other numbers of O-rings or other sealing members. In the example shown, a void 264 is provided to prevent the outer cell from contacting the top compression endcap fitting 144, which allows the top seal 168 at the inner cell wall 110 to bear all or substantially all of the compressive load imparted between the tope compression endcap fitting 144 and the inner cell wall 110, to better form the seal with the inner gasket 252. The void 265 also lessens the need for tight manufacturing tolerances that would otherwise be required to seal two concentric faces using gaskets (i.e., face seals). A similar arrangement (or others, as described below and/or elsewhere) may be provided to realize at least a portion of the bottom seal 170.
In the embodiments of
The tension rod(s) 174 may include threads cooperating with at least one threaded fastener 176 to facilitate tightening of the top compression endcap fitting 144 and/or the bottom compression endcap fitting 156 onto the outer cell wall 102 and the inner cell wall 110. The top compression endcap fitting 144 and/or the bottom compression endcap fitting 156 may each include a support 172 through which the tension rod 174 exerts the compression force. The support(s) 172 may be threaded or non-threaded to interact with the tension rod(s) 174 and/or with threaded fastener(s) 176. As an alternative to threads, springs, clamps, air pressure, and/or other mechanisms may be used to apply the compression force. The support(s) 172 may be constructed of stainless steel (SS316), an austenitic nickel-chromium-based alloy, a nickel-chromium-iron-molybdenum alloy, or aluminum, for example. The support(s) 172 alternatively or additionally may be constructed of another material. In the example embodiments shown in
Referring back to
As shown in
C. Reactor Cell Assembly with Light Housing Having Outer and Inner IR Lamps
As shown in
In embodiments in which the reactor cell assembly 100 is a photocatalytic reactor cell assembly, the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 may include a photocatalyst packed bed upon which emitted incident light (e.g., in the near-IR spectrum) from the pluralities of photon emitters 142a and 142b activates continuous photo-induced gas-phase reactions as at least one gaseous reactant flows through the photocatalyst packed bed to produce at least one resultant gaseous product. The IR lamps may additionally supply heat to the photocatalyst packed bed to further catalyze the reaction(s). In alternative embodiments in which the reactor cell assembly 100 is a thermal catalytic reactor cell (with no photocatalyst in the packed catalyst bed), the IR lamps in the plurality of photon emitters 172a and/or 172b may simply provide infrared radiative heating to the catalyst bed. Since the IR lamps are located on both sides of the annular volume 120 between the outer cell wall 102 and the inner cell wall 110, radiative heating is distributed more evenly and directly into the catalyst packed bed compared to conventional thermal reactors.
As shown in
Infrared radiation is electromagnetic radiation with wavelengths longer than those of visible light. For example, while the visible light spectrum may have wavelengths from about 380 nm to about 750 nm, infrared radiation may have wavelengths from about 750 nm to about 1 mm. Infrared radiation is emitted or absorbed by molecules when they change their rotational/vibrational movements. This absorption of radiation is commonly associated with an increase in temperature of the molecule. The maximum amount of radiation emitted by an ideal emitter (a black body) is proportional to the 4th power of its temperature:
where σ is the Stefan-Boltzmann constant. The introduction of non-ideality in an emitter's ability to radiate energy requires the addition of a proportionality constant ε, known as emissivity, which is the ability of a body to emit infrared energy. Typical emissivity values range from 0.02 (e.g., for mirrors or polished gold) to as high as 0.95 (e.g., for oxidized surfaces and carbon).
Infrared heating can be applied to a target by using an electrical infrared heater technology in which electric current is passed through a resistive filament such as tungsten or nichrome wire such that it glows and emits infrared radiation. The usable range of infrared radiation for industrial applications is from 760 μm to about 10,000 nm (10 μm) and is classified into three categories (short-wave, high-intensity; medium-wave, medium-intensity; and long-wave, long-intensity), as illustrated in the table 1400 shown in
Various embodiments of the reactor cell assemblies disclosed herein utilize short-wave IR lamps (e.g., IR lamp 178) to impart heat to the catalyst bed contained in the reactor cell (i.e., in the annular volume between the outer cell wall and the inner cell wall). The IR lamps are provided in the light housing (which may be simply a circular grouping or bank of the IR lamps themselves) fabricated with IR reflective materials (e.g., the reflective coating 186) to contain substantially all of the emitted radiation within the reactor cell assembly. Short-wave IR lamps generate radiation with a peak wavelength of 1.25 μm from a filament (e.g., the tungsten filament 180) that is at a temperature of 2200° C. The quartz envelope 182 housing the tungsten filament 180 has excellent high temperature stability and transmits over 97% of the infrared radiation generated by the emitter (at 677° C.), as illustrated in the graph 1500 of
The infrared-transmission characteristics of quartz help to overcome the limitations posed by the low thermal conductivity of quartz, making it a good candidate for construction of the outer wall and/or inner wall of the reactor assembly. In addition, infrared radiation (including near-IR radiation) is strongly absorbed by various gaseous species, such as reactant gases that might be utilized in the reactor cell assembly embodiments disclosed herein.
D. Reactor Cell Assembly with Light Housing Having Cooled Outer LED and Inner IR Lamps
As shown in
In embodiments in which the reactor cell assembly 100 is a photocatalytic reactor cell assembly, the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 may include a photocatalyst packed bed. Emitted incident light from the pluralities of photon emitters 142a and 142b (e.g., in the visible and the near-IR spectrums, respectively) activates continuous photo-induced gas-phase reactions as at least one gaseous reactant flows through the photocatalyst packed bed to produce at least one resultant gaseous product. The IR lamps may additionally or alternatively supply heat to the photocatalyst packed bed to further catalyze the reaction(s).
Also illustrated in
In addition to the outer cooling block 134, an inner cooling block (not shown) may be included to cool the photon emitters 142b (IR lamps) in the inner portion 132b of the light housing. For example, such an inner cooling block may have a structure and form factor similar to what is illustrated as inner cooling block 138 in
E. Reactor Cell Assembly with Light Housing having Outer IR Lamps and Cooled Inner LEDs
As shown in
In embodiments in which the reactor cell assembly 100 is a photocatalytic reactor cell assembly, the annular volume 120 between the outer cell wall 102 and the inner cell wall 110 may include a photocatalyst packed bed. Emitted incident light from the pluralities of photon emitters 142a and 142b (e.g., in the near-IR and the visible spectrums, respectively) activates continuous photo-induced gas-phase reactions as at least one gaseous reactant flows through the photocatalyst packed bed to produce at least one resultant gaseous product. The IR lamps may additionally or alternatively supply heat to the photocatalyst packed bed to further catalyze the reaction(s).
Also illustrated in
F. Reactor Cell Assembly with Applied Heating
Some example embodiments of the photocatalytic reactor cell assembly 100 additionally or alternatively include a heater to apply heat to at least the annular volume 120, thereby increasing the reaction rate of the photo-induced gas-phase reactions.
G. Reactor Cell having Outer Band Heater
The outer band heater 200 may take the form of a tube furnace heater, a ceramic fiber heater, or a heater coil wrapped around the outer cell wall 102. As shown in
Also shown in
In the example embodiment illustrated in
H. Reactor Cell having Embedded Annular Heater
With the exception of the annular heater 210, all components illustrated in
I. Reactor Cell having Embedded Helical Coil Heater
The reactor cell assembly 100 of
In an example embodiment, the coil heater 212 may be implemented as a helical tube 214 having a resistive heater wire 216 (e.g., a continuous filament, potentially including a hot section near the catalyst bed and cold sections away from the catalyst bed) disposed therein. For example, the coil heater 212 may be an IR coil lamp having a helical tube 214 made of quartz with a tungsten filament serving as the resistive heater wire 216, in a configuration similar to as shown in
J. Reactor Cell having Embedded IR Heaters
With the exception of the embedded IR heaters 220, all components illustrated in
The various reactor cell assembly embodiments set forth herein may serve as a platform technology allowing for multiple gas-phase chemical reactions on a solid catalyst, including reactions requiring high enthalpy of reaction and high activation energy via the use of light energy. For example, the following are some of the reactions and reaction types possible using one or more example embodiments set forth herein: steam methane reforming; dry methane reforming; partial oxidation of methane; autothermal reforming; decomposition of ammonia; ammonia synthesis; water gas shift reactions; reforming of heavier hydrocarbons (e.g., alkylated cyclics, resins and asphaltenes); Fischer-Tropsch synthesis; methanol synthesis; ethanol synthesis; hydrogenation to make saturated compounds; and dehydrogenation to make ethylene. Other gas-phase reactions and reaction types are also possible using various embodiments set forth herein.
Tables 2 and 3, below, illustrate example reaction condition ranges for two example chemical reactions that can be used for performing chemical reactions in various embodiments of the reactor cell set forth herein.
Tables 4 and 5, below, illustrate example hydrogen production rates by catalyst bed volume for various example reactor cell embodiments set forth herein.
COMSOL modeling was used to model light delivery to the photocatalyst bed for various light housing designs for an annular-shaped reactor cell assembly. This modeling has demonstrated that in some embodiments, an LED-based inner portion of the light housing (i.e., the interior of the annulus of the annular-shaped reactor) is capable of delivering approximately 63% of input electrical energy to the photocatalyst bed, when considering driver loss, electrical-to-heat loss at diode, and light housing loss. Similarly, the modeling demonstrated that an LED-based outer portion of the light housing (i.e., the exterior of the annulus of the annular-shaped reactor) is capable of delivery approximately 55% of input electrical energy to the photocatalyst bed, when considering driver loss, electrical-to-heat loss at diode, and light housing loss. Theoretical calculations were also performed to estimate IR lamp energy delivery efficiency. Based on these theoretical calculations, an example maximum IR energy efficiency to be achieved using various example embodiments disclosed herein is 75%.
To find the light intensity incident on the photocatalyst packed bed 126 and the efficiency of the light housing (inner and/or outer portions), a COMSOL ray-tracing simulation has been employed. Each LED (out of thousands or more of LEDs) acts as a point sources of light and emits radiation in the visible spectrum with a certain emissive power. The COMSOL simulation traces representative rays through a geometry representing the light housing and other components of the reactor cell assembly 100. The traced light rays bounce off surfaces based off Snell's law and the Fresnel equations. Each ray loses some energy with each boundary interaction and eventually falls below a certain energy threshold and stops propagating. The photocatalyst packed bed 126 is simulated as highly absorptive so that if a traced ray reaches the photocatalyst 126, it is completely absorbed for purposes of the COMSOL simulation.
The rays emitted from each individual LED (or other light source) are traced, and once all representative rays for all LEDs have been traced through the light housing geometry, the accumulated energy (in watts) that is deposited at each boundary is then divided by the area of the underlying mesh (e.g., a finite element mesh comprising triangles). This gives an intensity at each surface (e.g., triangular mesh surface segment) that may be used as a heat source for further heat transfer/fluid flow simulations. Mathematically, the resulting light intensity on any triangular mesh surface is:
where I is intensity in W/m2, A is area in m2, and Q is the power of a ray in W. Here the subscript i represents the index of mesh triangle and the subscript j represents the index of rays that have accumulated on that specific mesh triangle.
Table 6, below, illustrates experimental results and design calculations demonstrating performance of example embodiments of the reactor cell assembly set forth herein, using Photocatalytic Steam Methane Reformation (PSMR) as an example reaction. As can be seen, the conversion percentage is 83% for both experimental results and design calculations, which is believed to be a significant improvement over typical hydrogen-producing reactors.
The following numbered examples are embodiments.
1. A photocatalytic reactor cell assembly, comprising: an outer cell wall comprising a first tube having a first outer diameter and a first inner diameter; an inner cell wall comprising a second tube having a second outer diameter and a second inner diameter, wherein the second outer diameter is smaller than the first inner diameter, and wherein the outer cell wall and the inner cell wall are arranged concentrically about a vertical axis to define an annular volume between the outer cell wall and the inner cell wall; a top compression endcap fitting having an annular shape and comprising a reactant gas inlet; a bottom compression endcap fitting having an annular shape and comprising a product gas outlet, wherein the top compression endcap fitting and the bottom compression endcap fittings respectively form a top seal and a bottom seal with the outer cell wall and the inner cell wall; a photocatalyst packed bed positioned in the annular volume between the outer cell wall and the inner cell wall, wherein the photocatalyst packed bed comprises a photocatalyst; a porous base filter to position the photocatalyst packed bed in the annular volume, wherein the porous base filter is on an underside of the photocatalyst packed bed closer to the bottom compression endcap fitting than to the top compression endcap fitting, and wherein the porous base filter has a pore size chosen to be gas permeable but impermeable to the photocatalyst in the photocatalyst packed bed; and a light housing comprising an outer portion and an inner portion, wherein the outer portion is arranged concentrically around the vertical axis outside the outer cell wall, wherein the inner portion is arranged concentrically around the vertical axis inside the inner cell wall, and wherein at least one of the outer portion and the inner portion comprises a circumferential array of photon emitters arranged to uniformly emit photons incident on the photocatalyst packed bed, whereby the emission of photons incident on the photocatalyst packed bed activates continuous photo-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 resultant gaseous product exits via the gas outlet.
2. The photocatalytic reactor cell assembly of example 1, wherein the first tube is cylindrical.
3. The photocatalytic reactor cell assembly of example 1 or example 2, wherein the first tube has a circular cross section.
4. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the second tube is cylindrical.
5. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the second tube has a circular cross section.
6. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the first tube and the second tube are cylindrical.
7. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the first tube and the second tube have a circular cross section.
8. The photocatalytic reactor cell assembly of any of the preceding examples, 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 the photons emitted by the photon emitters.
9. The photocatalytic reactor cell assembly of any of the preceding examples, 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.
10. The photocatalytic reactor cell assembly of any of the preceding examples, 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.
11. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the outer cell wall and the inner cell wall comprises glass tubing.
12. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the outer cell wall and the inner cell wall comprises fused quartz glass.
13. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the outer cell wall and the inner cell wall comprises borosilicate glass.
14. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the outer cell wall and the inner cell wall comprises a metallic material.
15. The photocatalytic reactor cell assembly of any of the preceding examples, 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 the photons emitted by the photon emitters, and wherein at least a second portion of at least one of the outer cell wall and the inner cell wall comprises a reflective surface to reflect emitted photons into the photocatalyst packed bed.
16. The photocatalytic reactor cell assembly of any of the preceding examples, 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 the photons emitted by the photon emitters, and wherein at least a second portion of at least one of the outer cell wall and the inner cell wall comprises a scattering surface to scatter emitted photons into the photocatalyst packed bed.
17. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photocatalyst packed bed comprises the photocatalyst co-precipitated with a support material.
18. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photocatalyst comprises antenna-reactor plasmonic nanoparticles.
19. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photocatalyst packed bed is positioned vertically in a middle portion of the annular volume, and wherein an upper portion of the annular volume closest to the top compression endcap fitting is devoid of the photocatalyst packed bed to provide sufficient headspace for reactant gas mixing.
20. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the top compression endcap fitting and the bottom compression endcap fitting are constructed of stainless steel (SS316).
21. The photocatalytic reactor cell assembly of any of examples 1-19, wherein the top compression endcap fitting and the bottom compression endcap fitting are constructed of an austenitic nickel-chromium-based alloy.
22. The photocatalytic reactor cell assembly of any of examples 1-19, wherein the top compression endcap fitting and the bottom compression endcap fitting are constructed of a nickel-chromium-iron-molybdenum alloy.
23. The photocatalytic reactor cell assembly of any of examples 1-19, wherein the top compression endcap fitting and the bottom compression endcap fitting are constructed of aluminum.
24. The photocatalytic reactor cell assembly of any of the preceding examples, wherein a portion of at least one of the top compression endcap fitting and the bottom compression endcap fitting facing the photocatalyst packed bed is polished to reflect emitted photons into the photocatalyst packed bed.
25. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the top compression endcap fitting has at least one of a first outer circumferential flange to fit around a top portion of the outer cell wall or a first inner circumferential flange to fit inside a top portion of the inner cell wall.
26. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the bottom compression endcap fitting has at least one of a second outer circumferential flange to fit around a bottom portion of the outer cell wall or a second inner circumferential flange to fit inside a bottom portion of the inner cell wall.
27. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising a tension rod coupled to each of the top compression endcap fitting and the bottom compression endcap fitting to exert a compression force sufficient to cause the top seal and the bottom seal to be formed.
28. The photocatalytic reactor cell assembly of example 27, wherein the tension rod is arranged to be co-linear with the vertical axis about which the outer cell wall and the inner cell wall are concentrically arranged, and wherein the tension rod comprises threads cooperating with at least one threaded fastener to facilitate tightening of the top compression endcap fitting and the bottom compression endcap fitting onto the outer cell wall and the inner cell wall.
29. The photocatalytic reactor cell assembly of example 27 or example 28, wherein the top compression endcap fitting and the bottom compression endcap fitting each comprise a support through which the tension rod exerts the compression force.
30. The photocatalytic reactor cell assembly of example 29, wherein the tension rod and the supports are constructed of aluminum.
31. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising a plurality of tension rods coupled to each of the top compression endcap fitting and the bottom compression endcap fitting to exert a compression force sufficient to cause the top seal and the bottom seal to be formed.
32. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising at least one gasket to assist in causing at least one of the top seal or the bottom seal to be formed.
33. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising at least one O-ring to assist in causing at least one of the top seal or the bottom seal to be formed.
34. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing is cylindrical.
35. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing has a circular cross section.
36. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the inner portion of the light housing is cylindrical.
37. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the inner portion of the light housing has a circular cross section.
38. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the inner portion of the light housing and the outer portion of the light housing are cylindrical.
39. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing and the inner portion of the light housing have a circular cross section.
40. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the outer portion of the light housing or the inner portion of the light housing comprises an aluminum frame upon which the circumferential array of photon emitters is mounted.
41. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the outer portion of the light housing or the inner portion of the light housing comprises a cooling block upon which the circumferential array of photon emitters is mounted, and wherein the cooling block has at least one cooling passage through which a cooling fluid passes.
42. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the cooling block comprises walls defining a receptacle through which the cooling fluid is passed at a predetermined flow rate.
43. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the cooling fluid has a predetermined heat capacity.
44. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the circumferential array of photon emitters comprises a plurality of LEDs mounted on at least one of the aluminum walls of the cooling block, whereby the cooling fluid passing through the receptacle assists in cooling the plurality of LEDs.
45. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the circumferential array of photon emitters comprises a plurality of LEDs, and wherein at least one of the cylindrical shell of the light housing or the inner portion of the light housing comprises a cooling block having at least one of a plurality of coolant passages of a plurality of baffles for passing a cooling fluid through the aluminum cooling block to assist in cooling the plurality of LEDs.
46. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion comprises an outer cooling block and the inner portion comprises an inner cooling block, the outer cooling block and the inner cooling block being configured to assist in cooling the photon emitters.
47. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing comprises the circumferential array of photon emitters arranged on an inner surface of the outer portion to uniformly emit photons incident on the photocatalyst packed bed.
48. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the inner portion of the light housing comprises the circumferential array of photon emitters arranged on an outer surface of the inner portion to uniformly emit photons incident on the photocatalyst packed bed.
49. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing comprises a first portion of the circumferential array of photon emitters arranged on an inner surface of the outer portion to uniformly emit photons incident on the photocatalyst packed bed, and wherein the inner portion of the light housing comprises a second portion of the circumferential array of photon emitters arranged on an outer surface of the inner portion to uniformly emit photons incident on the photocatalyst packed bed.
50. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing is of a clamshell design and comprises two sections coupled by a hinge to allow for installation or removal of the outer portion in the photocatalytic reactor cell assembly.
51. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the inner portion of the light housing fastens to the tension rod.
52. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion and the inner portion are each connected to at least one of the supports on at least one of the top compression endcap fitting and the bottom compression endcap fitting.
53. The photocatalytic reactor cell assembly of example 52, wherein the supports are constructed of aluminum.
54. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the light housing is fluid-cooled.
55. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the light housing is water-cooled.
56. The photocatalytic reactor cell assembly of any of the preceding examples in which the photon emitters are LEDs, wherein the light housing comprises a cooling system to maintain a surface on which the photon emitters are mounted at a temperature not exceeding 150 degrees Celsius.
57. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the light housing comprises at least one heat sink.
58. The photocatalytic reactor cell assembly of example 57, wherein the heat sink is constructed of aluminum.
59. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the light housing further comprises integrated control electronics to control the photon emitters.
60. The photocatalytic reactor cell assembly of any of the preceding examples, wherein both the outer portion and the inner portion have annular cross sections.
61. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the circumferential array of photon emitters comprises a plurality of LED boards adjacent to one another, each LED board comprising a plurality of LEDs.
62. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photon emitters are selected to emit photons having a sufficient energy and wavelength to activate the photo-induced gas-phase reactions.
63. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photon emitters comprise Light-Emitting Diodes (LED) to emit photons in the visible light spectrum.
64. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photon emitters comprise Infrared (IR) lamps to emit photons in the near-IR spectrum.
65. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the photon emitters are selected from the group consisting of UV lamps, IR lamps, arc lamps, or LEDs.
66. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising drivers for the photon emitters, wherein the drivers are selected to operate at 50% or greater power load in order to improve driver efficiency.
67. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the circumferential array of photon emitters comprises a plurality of infrared (IR) lamps arranged adjacent to one another annularly around the vertical axis.
68. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion comprises the circumferential array of photon emitters in form of infrared (IR) lamps arranged adjacent to one another annularly around the vertical axis and outside of the outer cell wall, wherein each IR lamp comprises a reflective coating to reflect IR radiation toward the photocatalytic packed bed, and wherein the reflective coating of each IR lamp is on a surface of the IR lamp distal from the vertical axis.
69. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the inner portion comprises the circumferential array of photon emitters in form of infrared (IR) lamps arranged adjacent to one another annularly around the vertical axis and inside of the inner cell wall, wherein each IR lamp comprises a reflective coating to reflect IR radiation toward the photocatalytic packed bed, and wherein the reflective coating of each IR lamp is on a surface of the IR lamp proximal to the vertical axis.
70. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the porous base filter comprises a gas-permeable structural material.
71. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the porous base filter comprises at least one of porous metal, quartz wool, or ceramic.
72. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the porous base filter comprises stainless steel (SS316), an austenitic nickel-chromium-based alloy, or a nickel-chromium-iron-molybdenumm alloy.
73. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the porous base filter has an annular shape.
74. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising a heater to heat the annular volume, thereby increasing the reaction rate of the photo-induced gas-phase reactions.
75. The photocatalytic reactor cell assembly of any of the preceding examples, wherein the outer portion of the light housing is a heater that heats the annular volume to thereby increase the reaction rate of the photo-induced gas-phase reaction.
76. The photocatalytic reactor cell assembly of example 74 or example 75, wherein the heater is selected from a tube furnace heater or a band heater.
77. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising an immersion infrared (IR) coil lamp disposed in a helical quartz tube in the annular volume.
78. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising a heater embedded in the annular volume, wherein the heater comprises a plurality of infrared (IR) lamps arranged adjacent to one another annularly around the vertical axis between the inner cell wall and the outer cell wall.
79. The photocatalytic reactor cell assembly of any of the preceding examples, further comprising an annular heater immersed in the annular volume.
80. The photocatalytic reactor cell assembly of any of the preceding examples, wherein at least one of the first tube or the second tube comprises a plurality of cylindrical portions having different diameters, and wherein the cylindrical portions are joined end-to-end via angular connecting portions.
The above detailed description sets forth various features and operations of the disclosed systems, apparatus, devices, and/or methods with reference to the accompanying figures. The example embodiments described herein and in the figures are not meant to be limiting, with the true scope being indicated by the following claims. Many modifications and variations can be made without departing from its scope, as will be apparent to those skilled in the art. Functionally equivalent systems, apparatus, devices, and/or methods within the scope of the disclosure, in addition to those described herein, will be apparent to those skilled in the art from the foregoing descriptions. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations. 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 herein by reference for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/031444 | 5/27/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63202099 | May 2021 | US |
