Process intensive reactor with reduced thermal stresses.

Abstract

Reactors that are subject to large variations in temperature are subject to thermal stresses that may lead to failure or process interruptions. In the present invention, a reactor design is provided that protects the reactor from thermal stresses. By providing expansion joints and varying wall thickness or stiffness to accommodate thermal expansion, thermal stresses can be reduced.

Description

[Technical field]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 245,182, filed September 16, 2021. [Background technology]

[0002] TeGrotenhuis et al., Zheng et al., and Wegeng et al. have designed reactors to use solar radiation from a solar concentrator. See U.S. Patent Nos. 10,981,141, 11,358,111, and 9,950,305, which are incorporated herein by reference. Typically, they are disk-shaped reactors whose outer surface is mated with a solar concentrator. However, this work does not describe a means to reduce stress from thermal expansion.

[0003] Integrated heat transfer reactors with small channels have long been used for thermochemical reactions. Designs for these reactors have addressed the problem of thermal expansion. For example, in U.S. Pat. No. 7,931,875, Tonkovich et al. address the problem of thermal expansion by leaving the hottest end of the reactor free from expansion. U.S. Pat. Nos. 9,134,079 and 9,475,026 describe various manifold designs and flow control through multiple parallel channels. Despite these and other achievements, there remains a need to reduce thermal stresses and control flow in disk-shaped reactors that take in energy from the environment (e.g., from solar concentrators or induction heating sources or other energy sources) through or within the outer wall of the reactor. Summary of the Invention

[0004] In a first aspect, the present invention provides a disc shaped device comprising: a disc including a central axis and a first set of channels radiating from the central axis towards an outer periphery of the disc, the first set of channels comprising a plurality of channels, each of the channels in the plurality of channels comprising at least one inlet arranged about the central axis; a fluid inlet arranged parallel to and along the central axis; and a plurality of connections between the fluid inlet and the at least one inlet of each of the channels, each channel having a first cross-sectional area perpendicular to the channel length, and each inlet or inlets having a second cross-sectional area. the disc includes a circular top wall across a major surface of the disc and a cylindrical side wall around an outer periphery of the disc, and further includes one or any combination of the following features: each channel in the plurality of channels includes an expansion joint along the channel length; the side wall is thicker or harder than the top wall; each channel in the plurality of channels has a width that is perpendicular to the length and thickness and that narrows towards the outer periphery of the disc such that the wall thickness increases towards the outer periphery; or the second cross-sectional area is at least 20%, or 50%, or 70% smaller than the first cross-sectional area.

[0005] In any of its aspects, the invention provides a method for producing a reactor comprising the steps of: each wall of the reactor is made of a single material, the single material being a superalloy; each channel in the plurality of channels includes an expansion joint along the length of the channel, the expansion joint being selected from the group consisting of a tongue and groove joint, an angled gap, a thinned wall, a thinned wall to gap, a bellows, or a gap with overlapping flanges; the expansion joint includes an angled gap, the angled gap being angled in the direction of flow, angled against the flow, or angled in a V-shape; the expansion joint is a tongue and groove joint; the expansion joint includes a thinned wall, the wall being at least 40% thinner (or at least 60% thinner) than the average thickness of the wall, the average being over the length of the channel not including the thinned section; the side wall is thicker than the top wall; or the side walls being made of a material having a harder material than the top wall; each of the channels in the plurality of channels having a width perpendicular to the length and thickness, the width narrowing toward the periphery of the disk such that the wall thickness increases toward the periphery; the central fluid inlet being perpendicular to each of the channels in the plurality of channels; the reactor including a first disk-shaped layer of reaction channels including a solid catalyst and a second disk-shaped layer including heat recoupling channels, reaction products in the first layer can pass through return channels in the second layer returning toward the central axis; the second cross-sectional area being at least 20%, or 50%, or 70% less than the first cross-sectional area; the expansion joint including a bellows and including a central opening through the entire thickness of the disk-shaped device.

[0006] The invention also includes a method of conducting a thermochemical reaction, further comprising passing reactants through the device and applying heat into the reaction channel through an exterior wall of the reaction channel opposite the heat recoupling channel.

[0007] In a further aspect, the present invention provides a method of conducting a thermochemical reaction comprising: providing a disk shaped apparatus comprising: a disk including a central axis and a first set of channels radiating from the central axis towards an outer periphery of the disk, the first set of channels comprising a plurality of channels, each of the channels in the plurality of channels comprising at least one inlet arranged around the central axis; a fluid inlet arranged parallel to and along the central axis; and a plurality of connections between the fluid inlet and the at least one inlet of each of the channels, the disk including a circular top wall across a major surface of the disk and a cylindrical side wall around an outer periphery of the disk; and applying heat through a major surface of the disk (e.g., the outer horizontal plate of FIG. 8c), wherein the heat flux is higher near the center of the reactor and decreases towards the outer periphery of the reactor.

[0008] In any of its aspects, the invention may be further characterized by one or any combination of the following: the thermal chemical reaction is an endothermic reaction; the thermal chemical reaction includes a reforming or reverse hydrogenation reaction of a hydrocarbon (including methane); and the heat flux over 50% of the major surface area near the center of the disk is at least 10% greater or at least 20% greater than the 50% of the major surface area furthest from the center of the disk.

[0009] In another aspect, the invention provides a disk shaped device, the disk shaped device comprising: a central axis; a first set of channels radiating from the central axis towards an outer periphery of the disk, the first set of channels comprising a plurality of channels, each of the channels in the plurality of channels comprising at least one inlet arranged about the central axis; a fluid inlet arranged parallel to and along the central axis; and a plurality of connections between the fluid inlet and the at least one inlet of each of the channels, the disk having a circular top wall over a major surface of the disk and a cylindrical top wall around the outer periphery of the disk. The first set of channels defines a first layer, the device further comprising a second layer adjacent to the first layer, the second layer including a second set of channels extending from an outer periphery of the disk to a central axis, the first set of channels connecting to the second set of channels at the outer periphery such that flow from the first set of channels passes into the second set of channels, a catalyst is present in the first set of channels and a catalyst is present in the second set of channels such that at least 90% by mass of the catalyst in the second set of channels is present within 50% of the channels closest to the outer periphery.

[0010] The present invention also includes a method of conducting a thermochemical reaction in any of the devices described herein.

[0011] Typically, each channel has a cross-sectional area that is essentially constant over the channel length. Having a reduced cross-section at the inlet (the interface between the central fluid inlet and the multiple channels) creates a pressure drop that evens out or matches the flow to the multiple channels. The channels can have any length in one direction, typically at least 1 meter or at least 2 meters, heights are typically 1 mm to 1 cm but can be longer, and widths are typically 1 mm to 1 cm but can be longer.

[0012] Typically, each wall of the reactor is made of a single material, typically a superalloy that has good strength at high temperatures. In cases where the walls are welded to the sheet, the thickness is measured relative to the portion welded to the reactor, and in cases where the channels are formed in a single piece of material, the wall thickness is measured from the outside (side facing the environment) of the wall to the nearest edge of the channel. A "stiffer" wall is one that exhibits less deformation compared to a portion of equal area (in a dimension perpendicular to the thickness) when an equal force is applied at a selected temperature (800°C unless otherwise specified). In preferred embodiments, the thickness and / or stiffness is at least 10%, 20%, or 50% greater (in some embodiments, up to 100% greater), and typically a central fluid inlet is perpendicular to each of the channels in the multiple channels.

[0013] In some embodiments, the reactor is a two-layer reactor having a first disc-shaped layer of reaction channels containing a solid catalyst and a second disc-shaped layer containing heat recoupling channels, where the reaction products in the first layer can pass through return channels in the second layer back toward the central axis. The expansion joint is preferably selected from a tongue and groove joint, an angled gap (angled in the direction of flow, angled against the flow, angled in a V-shape), a thinned wall, a thinned wall to the gap, a bellows, or a gap with overlapping flanges. [Brief description of the drawings]

[0014] [Figure 1] These are two layers showing the cut outs exposing the flow distribution header (center of the reactor) along with the flow channel (bottom) and recuperation (top) channels. This shows the high temperature alloy portion of the reactor, and the optional foam catalyst insert is not shown, but will be placed within the lower channel in this view. [Diagram 2]Stresses (Von Mises stress in psi) in a two-layer reactor at 6 kW heat input, 85% conversion, and 280 psig internal pressure with increased reaction channel wall thickness near the reactor periphery to reduce thermal expansion and pressure induced stresses. The maximum stresses on the reactor surfaces are about 30 ksi (kilopounds per square inch) on the unheated surface and about 22 ksi on the top (hot) portion of the reactor. [Diagram 3] A three-layer reactor showing a cutaway (left) and the entire reactor (right). The three-layer reactor has catalyst-filled channels adjacent to the top and bottom of the reactor. The catalyst channels sandwich a recoupling channel. [Figure 4] This is the header for the three-layer reactor. [Diagram 5] 1 is a wireframe representation of the reactor interior at the center of the reactor, along with the cross spiral flow of the recoupling channels in the spoke arrangement of the inlet and outlet headers. [Figure 6] Finite element simulation results showing the stress in the reactor cross section near the periphery of the reactor. This reactor geometry has thicker reaction channel side walls closer to the device periphery. The maximum stress in the reaction channel wall is reduced to about 206 MPa (30 ksi). The maximum stress is also shifted toward the center of the reactor, where the temperature is lower and the stress can be better withstood. [Figure 7] Finite element simulation results showing the stresses in the reactor cross section near the reactor periphery. This reactor geometry incorporates a break in the inner wall of the reaction channel. This break acts as an expansion joint and reduces stresses in the internal reactor structure. In this simulation, the maximum stress was less than 20.6 MPa (3 ksi). [Figure 8a] 1A and 1B illustrate schematic cutaway side views of a three-layer reactor. [Figure 8b] Illustrates a configuration with gaps to allow for low stress expansion. [Figure 8c](Top) shows a view from above of the four horizontal layers of the reactor, (bottom) are the flow channels with gaps in the vertical walls separating the channels. [Figure 9] 1 illustrates generally the types of expansion joints that can be used to reduce thermal stresses in the reactor wall. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Reactor Design Designs have been developed for flat plate reactors for the steam reforming of hydrocarbons and other endothermic reactions, with variations including design improvements that reduce thermal expansion stresses. While these designs have been built on previous solar thermochemical methane steam reformers, current reactor designs have been developed for use with electrical induction heating. Other heat sources utilized include electricity (e.g., induction heating, resistive heating) as well as radiant energy (solar concentrators, lamps, microwaves, etc.).

[0016] These reactor designs are disc shaped and include two-layer and three-layer designs. Steam reforming reactors operate at high temperatures (700°C-900°C) and increasing pressures, e.g., up to 15-20 bar or higher. At these high temperatures and pressures, material strength is a major concern, and reactors are constructed from metal alloys such as cobalt superalloys (e.g., Haynes 230 and 282) that are specifically designed for high temperature applications.

[0017] At those high operating temperatures, creep rupture is a potential failure mechanism, and the reactor needs to be designed to minimize the stress in the reactor structure caused by the internal pressure, especially since the pressure-induced stress is constant at a given pressure during operation. Thermal expansion stress is also a concern. Unlike pressure-induced stress, thermal expansion stress relaxes with hold time at high temperatures due to creep, because thermal expansion stress is not a constant stress when operating, but is present when the device heats up and at the beginning of operation. A concern with thermal stress is its contribution to cyclic fatigue failure after multiple operating cycles as the reactor heats up and cools down. Thermal expansion stress can be greater than steady-state pressure-induced stress. It is desirable to maximize the operating life of the reactor, and to do this, both pressure and thermal expansion stress should be minimized. Now, with other unique features of flat-plate reactors, we discuss some design features that result in reducing thermal expansion stress in those flat-plate reactors. These features have been developed and analyzed through the use of finite element modeling (COMSOL Multiphysics) to model thermal expansion stresses, simulate reactor performance, and test improvements. The reactor design is explained by the modeling results and feature descriptions.

[0018] Two-layer reactor The first reactor concept is a two-layer design (two layers of flow channels) with reaction channels adjacent to the externally applied heat source and recoupling channels adjacent to the unheated surface of the disk. A cross-sectional view of half of this reactor design is shown in FIG. 1. In this two-layer design, the reaction gases enter the device near the center of the disk. Many endothermic reactions are achieved with this design, and for simulation purposes, it is assumed that the feed gas, consisting of a mixture of methane and steam, flows into a header that distributes the incoming gases into multiple catalyst-filled reaction channels (positioned like the spokes of a wheel) where the gas flows through a hot catalyst toward the periphery of the disk. The header is designed to distribute the feed gas evenly to the different reaction channels, even when the heat input into the reactor is not evenly distributed. This is achieved using an innovative header design with small inlet channels. Endothermic steam reforming reactions may occur in the catalyst-filled reaction channels that convert the steam and methane to hydrogen, carbon monoxide, and carbon dioxide. The endothermic steam reforming reaction requires the application of heat, and the catalyst-filled channels are heated by an external heat source applied to and / or within the exterior surface (bottom surface in the figure) adjacent to the catalyst channels. Types of heat sources that can be applied include electric induction heaters, electric resistance heaters, microwave heaters, concentrated sunlight from a dish, trough, or other solar concentrators, and other radiant energy sources. At the periphery of the device (disk), the flow changes direction and flows back toward the center of the disk-shaped reactor through recoupling channels that do not contain catalyst. As heat is transferred from the hot product gases in the reaction channels to the somewhat cooler reactant gases, the hot gases in those recoupling channels contribute some heat to the reaction. The recoupling channels can be shaped in a spiral or curved configuration to provide a cross spiral in relation to the reaction channels, and the reaction channels can be shaped in a spiral or curved configuration in relation to the straight recoupling channels, or alternatively, both sets of channels can be straight or spiral / curved.This crossed spiral or bent configuration helps spread heat among the reaction channels, reducing hot spots and allowing for more uniform conversion among the multiple reaction channels. This is particularly beneficial when using non-uniform heat sources such as concentrated solar or induction heating. Recoupling also reduces the temperature of the gases exiting the reactor, allowing the high temperature recuperator to operate at a lower temperature, increasing the strength, reducing the size, and / or increasing the life of the recouperator.

[0019] In either design, the reaction channel may have a height that is less than 1 mm in height (perpendicular to the flow and parallel to the direction of heat input) but preferably ranges from 1 to 10 mm or 3 to 6 mm, and the recoupling channel may have a height that is less than 1 mm in height but may range from 1 mm to 10 mm or 3 to 6 mm. The walls separating adjacent reaction channels or adjacent recoupling channels are preferably 0.3 mm to 2 mm or 0.5 mm to 1 mm thick. The walls separating the reaction and recoupling channels are preferably 0.4 mm to 4 mm or 0.5 mm to 2 mm thick.

[0020] During operation, this two-layer reactor experiences thermal expansion stresses as the heated outer wall adjacent to the reaction channel (bottom in FIG. 1) expands. The opposing unheated surface (top) is cooler and does not expand as much as the heater surface. This causes the reactor to dent (dish-bend), which creates thermal expansion stresses due to temperature gradients and non-uniform expansion created in the reactor metal structure.

[0021] The heat input can vary from less than 1 kW to tens of kW, or even more than 100 kW. In a preferred embodiment, the reactor has a heat input of 9.8 W / cm 2 ~20W / cm 2It is designed to operate at heat inputs of 6 kW to 12 kW resulting in heat fluxes in the range of 1000 MPa (3000 psi) to 1000 MPa (5000 psi). During operation, reactor temperatures are typically in the range of 600°C to 900°C, with the hottest parts of the reactor approaching and in some cases exceeding 900°C. At those high temperatures, creep rupture is a failure mechanism of concern. COMSOL simulations have been performed of a two-tiered reactor design assuming steam-methane reforming using a constant heating rate of 6 kW. First, a temperature profile for the reactor was solved, which was then used to calculate thermal expansion stresses along with the stresses resulting from the operating pressure. Initial calculations showed stresses as high as 330 MPa (50 ksi) on the reactor surface and similar stresses internally in some of the hottest parts of the reactor.

[0022] To reduce the stress in the hottest portion of the reaction sidewall, several design alternatives were simulated. One of them was to increase the thickness of the reaction channel sidewall near the periphery of the reactor. This reduces the tensile (pulling the top and bottom plates apart) stress due to pressure, but an unexpected benefit is that it reveals how increasing the strength of this portion of the reaction channel wall changes the thermal expansion stresses in the reactor. By increasing the stiffness of the sidewall near the hot periphery of the reactor, the maximum thermal expansion stress in the wall moves toward the center of the reactor. This is beneficial because an operating reactor becomes cooler toward the center, and metal alloys have better strength and creep rupture properties at lower temperatures.

[0023] Due to the stronger reaction channel walls, the simulations showed reduced thermal expansion stresses in the range of 130 MPa to 200 MPa (20 ksi to 30 ksi). The highest stresses were on the reactor surface and were located on the cooler unheated top surface. The hot surface of the reactor showed a maximum stress of about 22 ksi, which is 1 / 3 lower compared to the base case two-layer reactor design. Figure 2 shows the stresses on the exterior surface of the reactor, and stresses were also calculated on the reactor cross section (not shown).

[0024] Simulations performed for the two-layer reactor design used a constant heat flux across the surface of the reactor. The higher temperature gradients caused by the higher flux are the primary contributor to temperature gradients in the reactor structure resulting in higher than desired thermal expansion stresses. Higher heat fluxes also result in higher maximum temperatures. Since more heat is entering the reactor where it is coolest and has the highest material strength, it is beneficial to change the heat flux profile to one where the heat flux is higher near the center of the reactor and decreases toward the periphery of the reactor. The lower heat input toward the hotter periphery reduces the maximum temperature and temperature gradient in the hottest parts of the reactor. This can be achieved by adjusting the magnetic field through the design of the induction coils to cause more induction heating toward the center of the reactor with induction heating. This reduces the thermal expansion stresses in those hottest parts of the reactor.

[0025] 3-layer reactor A useful way to reduce thermal expansion stresses is to reduce the heat flux per area of ​​the reactor surface. However, it is also desirable to maximize the throughput of a reactor of a given size. To achieve this, a three-layer reactor design has been developed. The concept is a disk-shaped reactor that is heated on both sides. Figure 3 shows a diagram of a three-layer reactor.

[0026] In a three-layer reactor, methane and water vapor flow into headers that distribute the flow to catalyst-filled channels contained next to the top and bottom of the reactor. Similar to the channels in the two-layer reactor, the catalyst channels can be less than 1 mm thick or up to 1 cm thick or more in the direction parallel to the heat input, but are preferably 3 mm to 6 mm thick. Heat is added to both the top and bottom of the reactor to provide heat for the endothermic reaction. Heat can be applied using an electric induction heating source, an electric resistance heating source, or other heat sources as described in the previous discussion of the two-layer reactor. A special case is to use a solar concentrator to provide heat on one side and another method of heating on the other side.

[0027] The reactor is designed for a total heat input of 8 kW to 12 kW, although the reactor can be designed for lesser or greater heat fluxes ranging from less than 1 kW to tens of kWs (e.g., 50 kW or 70 kW) or even above 100 kW. Figure 4 shows a close view of the header, which distributes the flow to the catalyst-filled reaction channels and collects the flow from the recoupling channel. The inlet to the reaction channel contains a flow restriction channel (triangular in cross section) designed to provide a pressure drop to evenly distribute the flow to the multiple reaction channels.

[0028] The embodiments illustrated in the figures are not intended to limit the invention. For example, FIG. 4 illustrates a cylindrically symmetric manifold, but in alternative embodiments, the inlets and outlets can be off-center. A disk-shaped reactor can have a hole through the center and can be enclosed in an annular solenoid, for example, to inductively heat the reactor. Also, as in a two-layer reactor, the reaction and recoupling channels can be straight, curved (e.g., helical), or a combination thereof. One configuration with straight reaction channels and curved recoupling channels, resulting in counter-cross flow heat transfer (FIG. 5), is designed to help distribute heat between hot and cold reaction channels caused by potentially non-uniform heat input.

[0029] As the three-layer reactor is heated on both the top and bottom surfaces, both the hot top and bottom surfaces expand by approximately the same amount. Due to this, the reactor does not assume a dish or bowl shape, but remains relatively flat. However, since the reactor does not collapse, there may be increased thermal expansion stresses due to the hot outer surface and the cooler internal temperature of the reactor. Finite element simulations of the three-layer reactor have shown high stresses at the side walls of the reactor due to thermal expansion stresses. Figure 10 shows the temperature profile of a three-layer reactor with uniform heat flux on the top and bottom heated surfaces. The simulation assumes constant heat input on the top and bottom surfaces over the catalyst-containing portion of the reactor. In the simulation, the methane inlet flow and steam inlet flow are maintained at a steam-methane ratio of 3:1, and the inlet flow is adjusted to achieve the desired conversion. In the three-layer reactor, high thermal expansion stresses of over 344 MPa (50 ksi) caused by thermal expansion on the outer heated surfaces stretching the reaction channel sidewalls are seen at the reaction channel sidewalls near the periphery of the device stresses at the reaction channel walls.

[0030] Two methods were devised to reduce the thermal expansion stresses in the inner parts of the reactor. The first was to increase the thickness of the reaction channel sidewalls towards the periphery of the device. As in the case of the two-layer reactor, this reduces the overall stress in the sidewalls and moves the maximum stress in the sidewalls towards the center of the reactor, where the reactor is cooler and the high temperature alloys are better able to withstand the stress without fracture or deformation. Figure 6 shows the simulation results for a three-layer reactor with reaction channel sidewalls that are thicker towards the periphery.

[0031] A second method to reduce stress has been to incorporate one or more faults in the reaction channel walls. The faults act in a manner similar to expansion joints in a sidewalk or concrete floor, allowing the outside of the reactor to expand without cumulative stretching of the interior portions of the reactor. This expansion joint concept eliminates nearly all thermal expansion stresses. However, a challenge in utilizing expansion faults is that faults in the reaction channel walls provide a potential path for flow through the joint from the higher pressure reaction channel to the lower pressure recoupling channel. A substantial flow bypass (Figure 7) is detrimental to reactor performance and can result in overheating or poor conversion.

[0032] Thermal Expansion Joints Simulations show that thermal expansion faults can greatly reduce thermal expansion stresses in a three-layer design. This type of fault reduces stress in a two-layer reactor. Some concepts for providing insulation and preventing flow bypass are shown in Figures 8-9. The figures show the amount of strain (difference in length) seen in a reactor that is hotter outside the center and cooler in the center.

[0033] Another way to achieve the thermal barrier is to make the catalyst insertion with an impermeable wall that prevents flow from the catalyst channel through a structural wall between the reaction channel and the recoupling channel. This provides a sliding joint that prevents undesired flow bypass. Another concept is to provide a bellows structure in the sidewall that allows some bending and movement of the sidewall channel without creating significant stress. It is expected that the bellows portion will protrude into the recoupling channel to allow for easy filling of the catalyst channel. Thus, in a preferred structure, the bellows protrudes into the heat exchange channel and not into the reaction channel, so that the catalyst can be easily inserted into the reaction channel.

[0034] Other Reactor Concepts The two-layer reactor concept and the three-layer reactor concept described previously can be heated on one (two-layer) and both (three-layer) sides, respectively. Another concept that has been investigated is a two-layer reactor heated on both sides. In this concept, the flow channels are arranged in a similar manner as in the two-layer reactor, but a catalyst is also placed in the return channel. This catalyst in the return channel can reach the header or not reach the header at all. For example, the catalyst can be placed in the outer 1 / 2 or 1 / 3, or it can be placed inside the reactor. Heat is added on the surface next to the location of the catalyst placement. Using this concept, the heat flux can be reduced and the hottest part of the reactor is moved away from the edge of the reactor. This brings advantages in reducing the maximum reactor temperature for a given heat input and hydrogen production rate.

[0035] simulation Computer simulations were performed for two-layer and three-layer versions of the endothermic reactor. The simulations were for a methane reforming reaction incorporating a rhodium-based catalyst operating in the range of 700°C to 900°C to convert methane and water to synthesis gas. The reaction is endothermic, requiring the input of heat. With the circular plate (disk-shaped) reactor described here, heat is applied to one or more of the flat surfaces. Methane and water vapor enter the center of the plate and flow outward through catalyst-filled channels toward the periphery of the disk. At the periphery, the reacted stream consisting of hydrogen, carbon monoxide, carbon dioxide with unreacted methane and water is returned toward the center of the reactor in recoupling channels. The reaction requires high temperatures, and heat can be applied to the reactor surface adjacent to the catalyst through several means, including solar heating, induction heating, electrical resistance heating, microwave heating, or other means.

[0036] The reactor simulation was performed using COMSOL™ Multiphysics. A flow-reaction simulation was performed first. This simulation generated a temperature profile for the reactor based on the desired operating conditions including inlet flow rate, inlet temperature, heat input, and conversion. Using the model, the heat input was driven by pressure, and the flow rate was adjusted to reach the desired conversion.

[0037] After the temperature profile of the reactor was simulated, it was used to model the thermal stresses and other stresses in the part. This was done using the Structural Mechanics module in COMSOL Multiphysics. The stress-strain calculations used the average properties for Haynes 282 at the average operating temperature. The displacements of the reactor were constrained at the inlet header at three points, and a pressure boundary condition was applied to the inner surface of the reactor. To test the contribution of stress due to thermal expansion, the thermal expansion portion of the calculation can be turned off.

[0038] The invention includes any of the reactors, any of the components, and any combination of the components described herein. The invention also includes any of the methods, method steps, and any combination of the method steps described herein. The methods are typically described in a combination of components or any combination of components. The invention also includes systems including both the reactors or any combination of components or any combination of components, along with the fluids and / or catalysts and / or conditions described herein. The methods of the invention include methane steam reforming, reforming of methane or other hydrocarbons (including dry reforming), reverse hydrogenation, and other endothermic reactions. The reactor includes additional layers that may also incorporate exothermic reactions, such as partial oxidation.

Claims

1. A disc-shaped device, comprising: A central axis, the disk including a first set of channels radiating from the central axis toward an outer periphery of the disk, the first set of channels including a plurality of channels, each of the channels in the plurality of channels including at least one inlet disposed about the central axis; a fluid inlet disposed parallel to and along the central axis; a plurality of connections between the fluid inlet and the at least one inlet of each of the channels; Each channel has a first cross-sectional area perpendicular to the channel length, and each inlet or inlets has a second cross-sectional area; the disk includes a circular top wall across a major surface of the disk and a cylindrical side wall around the outer periphery of the disk; Features: each channel in the plurality of channels including an expansion joint along a length of the channel; the side wall being thicker or harder than the top wall; each channel in the plurality of channels has a width perpendicular to a length and a thickness, the width narrowing towards the periphery of the disk such that the wall thickness increases towards the periphery; or the second cross-sectional area being at least 20%, or 50%, or 70% smaller than the first cross-sectional area; The apparatus further comprising one or any combination of:

2. The apparatus of claim 1 , wherein each wall of the reactor is made of a single material, the single material being a superalloy.

3. The apparatus of claim 1 or 2, wherein each channel in the plurality of channels includes an expansion joint along the channel length.

4. 4. The apparatus of claim 3, wherein the expansion joint is selected from the group consisting of a tongue and groove joint, an angled gap, a thinned wall, a thinned wall to a gap, a bellows, or a gap with overlapping flanges.

5. 5. The apparatus of claim 4, wherein the expansion joint includes an angled gap, the angled gap being angled in the direction of flow, angled against flow, or angled in a V-shape.

6. 5. The apparatus of claim 4, wherein the expansion joint is a tongue and groove joint.

7. 5. The apparatus of claim 4, wherein the expansion joint includes a thinned wall that is thinned to a thickness that is at least 40% less (or at least 60% less) than an average thickness of the wall, the average being greater than the length of the channel not including the thinned section.

8. The device of claim 1 or 2, wherein the side wall is thicker or harder than the top wall.

9. The apparatus of claim 1 , wherein the sidewalls are made of a material having a harder property than the top wall.

10. 4. The apparatus of claim 3, wherein each of the channels in the plurality of channels has a width perpendicular to a length and a thickness, the width narrowing toward the outer periphery of the disc such that the wall thickness increases toward the outer periphery.

11. 10. An apparatus according to any preceding claim, wherein a central fluid inlet is perpendicular to each of the channels in the plurality of channels.

12. 10. The apparatus of any of the preceding claims, wherein the reactor comprises a first disc-shaped layer of reaction channels containing a solid catalyst and a second disc-shaped layer containing heat recoupling channels, and reaction products in the first layer can pass through return channels in the second layer returning towards the central axis.

13. 2. An apparatus according to any preceding claim, wherein the second cross-sectional area is at least 20%, or 50%, or 70% less than the first cross-sectional area.

14. The apparatus of claim 3 , wherein the expansion joint comprises a bellows.

15. 10. A device according to any preceding claim, wherein the disc shaped device has a thickness aligned with the central axis and includes a central opening through the entire thickness of the disc shaped device.

16. 13. A method for conducting a thermochemical reaction, the method further comprising passing reactants through the apparatus of claim 12 and applying heat into the reaction channel through an exterior wall of the reaction channel opposite a heat recoupling channel.

17. 1. A method for conducting a thermochemical reaction, comprising: Providing a disk-shaped device, the disk-shaped device comprising: A central axis, the disc including a first set of channels radiating from the central axis toward the outer periphery of the disc, the first set of channels including a plurality of channels, each of the channels in the plurality of channels including at least one inlet disposed about the central axis; a fluid inlet disposed parallel to and along the central axis; a plurality of connections between the fluid inlet and the at least one inlet of each of the channels; The disk includes a circular top wall across a major surface of the disk and a cylindrical side wall around the outer periphery of the disk. The providing, applying heat through the major surface of the disk (e.g., the outer horizontal plate of FIG. 8c), where the heat flux is higher near the center of the reactor and decreases towards the outer periphery of the reactor; The method comprising:

18. 18. The method of claim 17, wherein the heat flux over 50% of the major surface area near the center of the disk is at least 10% greater, or at least 20% greater, than the 50% of the major surface area furthest from the center of the disk.

19. A disc-shaped device, comprising: A central axis, the disc including a first set of channels radiating from the central axis toward the outer periphery of the disc, the first set of channels including a plurality of channels, each of the channels in the plurality of channels including at least one inlet disposed about the central axis; a fluid inlet disposed parallel to and along the central axis; a plurality of connections between the fluid inlet and the at least one inlet of each of the channels; the disk includes a circular top wall across a major surface of the disk and a cylindrical side wall around the outer periphery of the disk; the first set of channels defines a first layer; the device further comprising a second layer adjacent to the first layer; the second layer includes a second set of channels extending from the outer periphery to the central axis of the disk, the first set of channels connecting to the second set of channels at the outer periphery such that flow from the first set of channels passes into the second set of channels; The device, wherein a catalyst is present in the first set of channels and the catalyst is present in the second set of channels such that at least 90% by mass of the catalyst in the second set of channels is present within 50% of the channel length closest to the periphery.

20. 1. A method for conducting a thermochemical reaction, comprising:

20. The method comprising conducting a thermochemical reaction in an apparatus according to claim 19.

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