Steam reforming reactor with internal axial heating

Abstract

A steam reforming reactor may include a shell, an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube, a fluid inlet in fluid communication with the annulus, a fluid outlet in fluid communication with the annulus, a catalytic reactor disposed within the annulus, the catalytic reactor configured to allow fluid to flow through the annulus, and at least one internal heating device disposed within the inner tube, the at least one internal heating device configured to heat a fluid traveling through the annulus.

Description

STEAM REFORMING REACTOR WITH INTERNAL AXIAL HEATINGCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to United States Provisional Patent Application No. 63 / 510028, filed on June 23, 2023. The disclosure of the abovereferenced application is hereby expressly incorporated by reference in its entirety.FIELD

[0002] The present disclosure relates to heating configurations for steam methane reformer deploying annular catalytic reactors.BACKGROUND

[0003] A conventional steam methane reformer (“SMR”) emits approximately nine tons of CO2 for every ton of hydrogen produced even when using light hydrocarbon feed natural gas. Approximately 55%-60% of the CO2 attributable to the feed carbon content can be effectively removed from the syngas, using a process known as pre-combustion CO2 capture, and made available for sequestration. The remainder of the CO2, however, which mainly comes from the fuel combustion needed for providing the heat for steam reforming, must be captured from the SMR furnace flue gas in a process known as post-combustion CO2 capture. The post-combustion CO2 capture process is much more energy and capital intensive than pre-combustion capture due to inherent flue gas characteristics and continues to be technologically and economically challenging in terms of cost-effectiveness and reliability.

[0004] Thus, it would be desirable to reduce or eliminate the flue-gas CO2 from the SMR process and thereby also achieve nearly full decarbonization of hydrogen generation.SUMMARY

[0005] In a first aspect, a steam reforming device includes a shell; an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube; a fluid inlet in fluid communication with the annulus; a fluid outlet in fluid communication with the annulus; a catalytic reactor system disposed within the annulus, the catalytic reactorsystem configured to allow fluid to flow through the annulus; and at least one internal heating device disposed within the inner tube, the at least one internal heating device configured to heat a fluid flowing through the annulus.

[0006] In some embodiments, the at least one internal heating device is electrically powered.

[0007] In some embodiments, at least a portion of the shell is cylindrical. In some embodiments, the inner tube is disposed coaxially within the shell. In some embodiments, the at least one internal heating device is disposed coaxially within the inner tube.

[0008] In some embodiments, the at least one internal heating device is disposed with the inner tube such that the at least one internal heating device contacts the inner tube.

[0009] In some embodiments, the at least one internal heating device is separated from the inner tube by a central volume. In some embodiments, the steam reforming reactor further includes a conductive material disposed within the central volume.

[0010] In some embodiments, the at least one internal heating device is configured to release variable amounts of heat along a length of the inner tube.

[0011] In a second aspect, a system includes a plurality of reaction tubes, each reaction tube including: a shell; an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube; a fluid inlet in fluid communication with the annulus; a fluid outlet in fluid communication with the annulus; a catalytic reactor system disposed within the annulus, the catalytic reactor configured to allow fluid to flow through the annulus; and at least one internal heating device disposed within the inner tube, the at least one internal heating device configured to heat a fluid flowing through the annulus.

[0012] In some embodiments, the plurality of reaction tubes are arranged in at least one row.

[0013] In some embodiments, the at least one row includes a plurality of rows arranged parallel to each other.

[0014] In some embodiments, the system further includes an external heating device, the external heating device configured to supplement the heating provided by the at least one internal heating device of each reaction tube.

[0015] In some embodiments, the external heating device burns a portion of a product stream that has passed through at least one of the plurality of reaction tubes.

[0016] In some embodiments, the external heating device is electrically powered.

[0017] In some embodiments, the external heating device is further configured to release variable amounts of heat along a length of each inner tube.

[0018] In some embodiments, the external heating device is configured to independently control the variable amounts of heat released for each inner tube of each reactor tube.

[0019] In a third aspect, a method of steam reforming includes providing a fluid feed stream to a reaction device; passing the fluid feed stream over the catalytic reactor system; heating the fluid feed stream, via the at least one internal heating device, as it passes over the catalytic reactor system; reacting the fluid feed stream to form a product stream; extracting a first compound of interest from the product stream; and recycling at least a portion of the product stream back into the reaction device. The reaction device includes: a shell; an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube; a catalytic reactor disposed within the annulus, the catalytic reactor configured to allow fluid to flow through the annulus; and at least one internal heating device disposed within the inner tube.

[0020] In some embodiments, recycling at least a portion of the product stream comprises recycling at least a portion of a second compound of interest extracted from the product stream.

[0021] In some embodiments, providing a fluid feed stream includes providing a mixture of hydrocarbons and steam.

[0022] In some embodiments, the method further includes separating a carbon-rich stream from the product stream.

[0023] In some embodiments, recycling at least a portion of the product stream includes recycling the separated carbon-rich stream back into the reaction vessel.

[0024] In some embodiments, extracting the first compound of interest includes extracting carbon dioxide from the product stream.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The detailed description is set forth with reference to the accompanying figures. The use of the same numbers in different figures indicates similar or identical items.

[0026] For this discussion, the devices and systems illustrated in the figures are shown as having a multiplicity of components. Various implementations of devices and / or systems, as described herein, may include fewer components, and remain within the scope of the disclosure. Alternatively, other implementations of devices and / or systems may include additional components, or various combinations of the described components, and remain within the scope of the disclosure.

[0027] Figure 1A shows a front cross-sectional view of a system with a reaction vessel for steam reforming with an internal heating source.

[0028] Figure IB shows a top cross-sectional view of the system of Figure 1A, taken about the line B-B in Figure 1A.

[0029] Figure 2 shows an example embodiment of a system for steam reforming including a row of reaction vessels.

[0030] Figure 3 shows an example embodiment of a system for steam reforming including multiple tube rows.

[0031] Figure 4A shows an example embodiment of a system for steam reforming including tubes cluster arrangement.

[0032] Figure 4B shows a top cross-sectional view of the system of Figure 4A, taken about the line B-B in Figure 4A.

[0033] Figure 4C shows an example embodiment of outlet headers in a multi-ring configuration.

[0034] Figure 5 shows a schematic view of an example process for converting hydrocarbons into hydrogen while reducing the amount of carbon dioxide produced.

[0035] Figure 6 shows a schematic view of an example process for converting hydrocarbons into hydrogen while reducing the amount of carbon dioxide produced.DETAILED DESCRIPTION

[0036] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Thus, in some embodiments, part numbers may be used for similar components in multiple figures, or part numbers may vary from figure to figure. The illustrative embodiments described herein are not meant to belimiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. 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, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

[0037] The following detailed description is directed to certain specific embodiments of the development. Reference in this specification to “one embodiment,” “an embodiment,” or “in some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present technology. The appearances of the phrases “one embodiment,” “an embodiment,” or “in some embodiments” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but may not be requirements for other embodiments. Furthermore, embodiments of the development may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the technology described herein.

[0038] Steam reforming processes typically include reacting a hydrocarbon with steam and / or carbon dioxide over a catalyst to produce syngas, a mixture of hydrogen and oxides of carbon. The hydrogen content of the syngas is often increased by cooling the syngas and reacting it over a catalyst to convert some of its carbon monoxide and remaining water vapor to additional hydrogen and carbon dioxide. A final treatment is to separate the hydrogen product from the remainder of the syngas which may include steam, CFU, CO, and CO2.

[0039] The process using a conventional steam methane reformer (“SMR”) emits approximately nine tons of CO2 for every ton of hydrogen produced even when using light hydrocarbon feed natural gas. Approximately 55%-60% of the CO2 attributable to feed carbon can be effectively removed from the syngas, using a process known as pre-combustion CO2 capture, and made available for sequestration. The remainder of the CO2, however, which mainly comes from the fuel combustion needed for providing the heat for steam reforming,must be captured from the SMR furnace flue gas in a process known as post-combustion CO2 capture. The post-combustion CO2 capture process is much more energy and capital intensive than pre-combustion capture and continues to be technologically and economically challenging in terms of cost-effectiveness and reliability.

[0040] It would be desirable to reduce the amount of CO2 generated from the fuel combustion of heating a steam methane reformer while still providing the reformer with sufficient heat for the necessary reactions to take place.

[0041] Generally described, the present disclosure provides systems and methods for steam reforming using an internal heater. The internal heating device may be disposed within a reactor tube within an empty axial volume. As described herein, a reactor tube can be a variety of plant equipment, including vessels, containers, exchangers, pipes, devices, or other various equipment. An internal heating device can provide efficient and constant heating to reaction components within the reactor tube. Conventional steam reforming reactors and methods use external heaters to heat the reaction tubes. Such external heaters burn carbon rich fuel to heat the reactor tubes, resulting in large amounts of carbon dioxide being produced. Moreover, conventional steam reforming reactors do not have an annular configuration, and thus may not be compatible with internal heating. Advantageously, embodiments of the present disclosure provide for effective production of hydrogen through a steam reforming process while reducing the amount of carbon dioxide leaving the system. The external heating requirements of a reactor tube may be reduced or eliminated by employing an internal heating device like those described herein, in conjunction with an annular reactor configuration that is adapted to receive heat efficiently from an internal heating device. Employing an internal heating device reduces the amount of carbon dioxide released in a flue gas created by burning carbon rich fuel in an external heater.

[0042] Advantageously, embodiments of the present disclosure also provide for efficient modular designs for steam reforming systems. Using conventional methods, using a modular design for a steam reforming system would be limited by the external heating systems. Each reactor tube would be ideally positioned such that it was adequately heated. Embodiments of the present disclosure provide for more efficient and compact modular reactor designs. The inclusion of internal heaters allows for large numbers of reactor tubes to be placed in close proximity to each other while still providing adequate heating to each reactor.

[0043] Figure 1 A shows a front cross-sectional view of a system 100 including a reaction tube 101 with an internal heating source. Figure IB shows a top cross-sectional view of the reaction tube 101 taken about the line B-B shown in Figure 1A. The cross section of Figure 1A is taken about the line A-A shown in Figure IB. The system 100 includes a reaction tube 101 and a power feeder 180. In some embodiments, the system 100 may further include an external heater. It is appreciated that the reaction tube 101 can be used in variety of equipment and devices without departing from the scope of this application.

[0044] As seen in Figure 1A, the reaction tube 101 includes a shell 110, an inner tube 120, a catalytic reactor 130, and an internal heating device 140. As seen in Figure IB, the shell 110 can have a generally circular cross-section and can be substantially cylindrical in shape. The shell 110 includes a fluid inlet 112 and a fluid outlet 114. In some embodiments, the shell 110 may have an insulating material disposed on the inner surface 111 of the shell 110 to prevent heat from escaping the reaction tube. In some embodiments, the shell 110 may be composed of an insulating material. In some embodiments, for example where the system100 comprises an external heating device, the shell 110 may not comprise an insulating material. In some embodiments, the shell 110 may be composed of a heat conductive material. In some embodiments, the diameter of the shell 110 may decrease at a second end 115 of the shell 110 adjacent to the fluid outlet 114.

[0045] As shown in Figure 1A, the fluid inlet 112 is positioned at a first end 113 of the shell 110. A fluid feed stream 117 enters the fluid inlet 112 and flows into the reaction tube 101. In some embodiments, the diameter of the fluid inlet 112 may be increased or decreased to alter the flow rate of a fluid feed stream 117 entering the shell 110. In some embodiments, the flow rate may be adjusted to alter retention times of the fluid within the shell 110.

[0046] The fluid outlet 114 is positioned at a second end 115 of the shell 110 generally opposite the first end 113. A fluid product stream 119 flows from the reaction tube101 out through the fluid outlet 114. In some embodiments, the diameter of the fluid outlet 114 may be increased or decreased to alter the flow rate of a fluid product stream 119 exiting the reaction tube 101. In some embodiments, the flow rate may be adjusted to alter retention times of the fluid within the reaction tube 101.

[0047] The inner tube 120 is disposed with the shell 110 and may also be substantially cylindrical in shape. In some embodiments, the inner tube may be a hollowcylinder. In some embodiments, the inner tube is disposed concentrically or coaxially within the shell 110. In some embodiments, the inner tube 120 may be composed of a conductive material. The inner tube 120 is disposed within the shell 110 such that inner tube does not contact the shell 110, thereby forming an annulus 150 between the shell 110 and the inner tube 120. As seen in Figure 1A, the annulus 150 is in fluid communication with the fluid inlet 112 and the fluid outlet 114.

[0048] As seen in Figure 1A, the catalytic reactor 130 is disposed within the annulus 150. The catalytic reactor 130 may take the form of a structured packing or other suitable form, thereby allowing a fluid to flow through the catalytic reactor 130. In some embodiments, the structured packing may be catalyst coated. In some embodiments, the catalytic reactor 130 may take the form of a honeycomb catalytic reactor. In some embodiments, the catalytic reactor 130 may be composed of a substrate. The substrate may be a metal or a ceramic. In some embodiments, the catalytic reactor 130 may contain nickel, platinum, palladium, rhodium, rhenium, and / or other suitable catalytic materials. In some embodiments, the catalytic reactor 130 may be suitable for promoting a steam reforming reaction at temperatures less than 600° C.

[0049] As seen in Figures 1A and IB, the internal heating device 140 is disposed within the inner tube 120. In some embodiments, the internal heating device may include one or a plurality of individual heating devices disposed within the inner tube 120. In some embodiments, the internal heating device 140 is disposed concentrically or coaxially within the inner tube 120. The internal heating device 140 may be in the form of a cylinder or a rod. In some embodiments, the internal heating device 140 may be a hollow cylinder. In some embodiments, the inner tube 120 may be separated from the internal heating device 140 by a central volume 160. In some embodiments, the central volume 160 may be filled with a conductive material to promote heat transfer through the reaction tube 101. The presence of a central volume 160 may be beneficial when internal heating devices of various sizes are employed. In some embodiments, the inner tube 120 may contact the internal heating device 140. In some embodiments, the internal heating device 140 is fluidly isolated from the annulus. In some embodiments, the internal heating device 140 is configured to release varying amounts of heat along the length of the shell 110. This may be beneficial to avoid localized overheating especially near the second end 115 of the shell 110. In some embodiments, the internal heatingdevice 140 is configured to release varying amounts of heat along the length of the inner tube 120.

[0050] The power feeder 180 is electrically connected to the internal heating device 140. The power feeder 180 supplies the internal heating device 140 with electrical power. In some embodiments, the power feeder 180 provides the internal heating device 140 with electrical power in the form of an alternating current or in the form of a direct current.

[0051] In this embodiment, a fluid feed stream 117 flows into the shell 110 of the reaction tube 101 via the fluid inlet 112. In some embodiments, the fluid feed stream 117 comprises hydrocarbons and steam. In some embodiments, the hydrocarbons may be light hydrocarbons. In some embodiments, light hydrocarbons are hydrocarbons with low molecular weight. For example, light hydrocarbons may include methane, ethane, propane, butane or a combination or mixture of the above. In some embodiments, the fluid feed stream 117 may be compressed natural gas (CNG) mixed with steam. The fluid feed stream 117 enters the annulus 150 of the reaction tube 101 and passes through the catalytic reactor 130. The fluid feed stream 117 is heated via the internal heating device 140 while it passes over and through the catalytic reactor 130. In some embodiments, an external heater may provide additional heating to the reaction tube 101. While passing over the catalytic reactor 130 and being heated, the fluid feed stream 117 reacts. In some embodiments, the fluid feed stream 117 reacts to form syngas comprising a mixture of steam, CH4, CO, and CO2. The reacted syngas exits the reaction tube 101 via the fluid outlet 114.

[0052] This configuration is beneficial for reducing the amount of CO2 released in a flue gas because the external heating requirements for the reaction tube 101 arc reduced or eliminated due to the internal heating device 140. This configuration may be beneficial for providing an increased heat transfer rate to the fluid within the annulus 150 without a pressure drop penalty. This configuration is additionally beneficial for heating a hydrocarbon and steam feedstock with renewable and / or green energy. Furthermore, this configuration allows a plurality of reaction tubes to used beneficially in a modular fashion without being constrained by the limitations of providing external heating to each of the reaction tubes.

[0053] Figure 2 shows an example embodiment of a system for steam reforming including a row of internally heated reactors. As seen in Figure 2, the system 200 includes a plurality of reaction tubes 101, a feed inlet header 216, an outlet header 218, and a power feeder280. In some embodiments, the system 200 can additionally include an external heating device290.

[0054] As seen in Figure 2, the plurality of reaction tubes 101 arc aligned in single row 202. Each reaction tube 101 may include a shell 110, an internal heating device 140, a fluid inlet 112 and a fluid outlet 114. Additionally, each reaction tube 101 may include an inner tube, an annulus, and a catalytic reactor like those described above with reference to Figures 1A and IB. Each reaction tube 101 may be similar or identical to the reaction tube 101 described above in connection with Figures 1A and IB.

[0055] As seen in Figure 2, the feed inlet header 216 is in fluid communication with the fluid inlet 112 of each reaction tube 101. A fluid feed stream flows through the feed inlet header 216 to the fluid inlet 112 of each reaction tube 101 and into the annulus of the reaction tube 101. The feed inlet header 216 may supply each reaction tube 101 with approximately equal amounts of a fluid feed stream. In some embodiments, the feed inlet header 216 supplies each reaction tube 101 with a variable amount of a fluid feed stream. In some embodiments, the feed inlet header 216 may be positioned above or laterally displaced from the external heating device 290 (if present) such that the fluid feed stream is not heated by the external heating device 290. In some embodiments, the feed inlet header 216 may be positioned such that a fluid feed stream traveling in the feed inlet header 216 is at least partially heated by the external heating device 290.

[0056] The outlet header 218 is in fluid communication with the fluid outlet 114 of each reaction tube 101. A fluid product stream exits the reaction tube 101 via the fluid outlet 114 of each reaction tube 101. The fluid product stream flows from the fluid outlet 114 to the outlet header 218.

[0057] The power feeder 280 is in electrical communication with the internal heating device 140 of each reaction tube 101. In some embodiments, the power feeder 280 may provide equal amounts of electrical power to the internal heating device 140 of each reaction tube 101. In some embodiments, the power feeder 280 may provide varying amounts of electrical power to the internal heating device 140 of each reaction tube 101. In some embodiments, the power feeder 280 may be configured to adjust the heating of each individual reaction tube 101 or for a cluster of reaction tubes 101 without affecting the other reaction tubes 101.

[0058] The external heating device 290 may be positioned such that it heats each of the plurality of reaction tubes 101 equally. In some embodiments, the external heating device 290 may be electrically powered. In some embodiments, the external heating device 290 may bum the remaining product feed stream after the product feed stream has been processed and filtered to heat the plurality of reaction tubes 101. In some embodiments, the external heating device burns a mixture of hydrocarbon fuel and a portion of a product feed stream. In some embodiments, the external heating device 290 is configured to release heat variably along the length of the tube row 202. In some embodiments, the external heating device 290 is configured to supplement the heating provided to each reaction tube 101 by each internal heating device 140.

[0059] In some embodiments, the number of reaction tubes 101 can be reduced by increasing the length of each reaction tube 101. This configuration may be beneficial for increasing the length of each reaction tube 101 as each reaction tube 101 is electrically heated by the internal heating device 140, thus the length of each reaction tube is not limited by the flame length or other limitations of a non-electric heater.

[0060] In some embodiments where an external heating device is not present, the plurality of reaction tubes 101 in the single row 202 may be disposed in close proximity to each other.

[0061] Figure 3 shows an example embodiment of a system for heating using multiple tube rows. As seen in Figure 3, the system 300 may include a plurality of rows 302, an overhead inlet header 322, and a combined outlet header 324. The components of system 300 may be substantially similar to those of system 200 described above in connection with Figure 2.

[0062] The plurality of rows may be positioned parallel to each other. The plurality of rows may be positioned proximate each other. Each row 302 may include a plurality of reaction tubes 101, a feed inlet header 316, an outlet header 318, and a power feeder 380. Each row 302 may be substantially similar to the row 202 described above in connection with Figure 2.

[0063] As seen in Figure 3, the plurality of reaction tubes 101 may be aligned in a plurality of rows 302. Each reaction tube 101 may include a shell 110, an internal heating device 140, a fluid inlet 112 and a fluid outlet 114. Additionally, each reaction tube 101includes an inner tube, an annulus, and a catalytic reactor like those described above. Each reaction tube 101 and its components may be similar or identical to the reaction tube lOland the components of the reaction tube 101 described above in connection with Figures 1A-1B.

[0064] As seen in Figure 3, the overhead inlet header 322 is in fluid communication with the feed inlet header 316 of each row 302. A fluid feed stream flows through the overhead inlet header 322 to the feed inlet header 316 of each row 302. The fluid feed stream then flows through the feed inlet header 316 of each row into the fluid inlet 112 of each reaction tube 101 and into the annulus of the reaction tube 101. The overhead inlet header 322 may supply each feed inlet header 316 with approximately equal amounts of a fluid feed stream. In some embodiments, the overhead inlet header 322 may supply feed inlet header with varying amounts of a fluid feed stream.

[0065] The combined outlet header 324 is in fluid communication with the outlet header 318 of each row 302. A fluid product stream exits the reaction tube 101 via the fluid outlet 114 of each reaction tube. The fluid product stream flows from the fluid outlet 114 to the respective outlet header 318. The fluid product streams from each outlet header 318 to the combined outlet header 324.

[0066] In conventional steam reforming systems comprising multiple rows, the rows must be spaced out to provide sufficient space for external heaters to provide heating to every row. This configuration as portrayed in Figure 3 may be beneficial for reducing the amount of space needed for a multiple tube row layout. The lack of an external heating device allows each row 302 to be placed in close proximity to each other.

[0067] Figures 4A and 4B show an example embodiment of a system 400 for heating using multiple tubes in a cluster formation. Figure 4A shows a front view of the system 400 with the outer surface removed for clarity purposes. Figure 4B shows a top cross-sectional view of the system 400 taken about the line B-B shown in Figure 4A.

[0068] As seen in Figures 4A and 4B, the system 400 may include a plurality of reaction tubes 101 and an outer enclosure 492. The system 400 may additionally comprise a power feeder, an outlet header, and an inlet header like those described above in connection with Figure 2 and Figure 3.

[0069] Each reaction tube 101 may include a shell 110, an internal heating device 140, a fluid outlet 114, an inner tube 120, an annulus 150, and a catalytic reactor 130.Additionally, each reaction tube 101 may include a fluid inlet like those described above with reference to Figures 1A and IB. Each reaction tube 101 may be similar or identical to the reaction tube 101 described above in connection with Figures 1A and IB.

[0070] As seen in Figure 4B, the plurality of reaction tubes 101 may be disposed within an outer enclosure 492. The outer enclosure 492 may be substantially cylindrical in shape. In some embodiments, the outer enclosure 492 may comprise supports configured to hold the plurality of reaction tubes 101 in place. In some embodiments, the interior of the outer enclosure 492 may be insulated to prevent heat loss.

[0071] The plurality of reaction tubes 101 may be disposed in the outer enclosure in a cluster formation. In some embodiments, the plurality of reactions tubes may be disposed within outer enclosure such that the reactions tubes form at least one ring within the outer enclosure. The rings may be disposed concentrically or coaxially within the outer enclosure.

[0072] In some embodiments, the plurality of reaction tubes may be disposed within the outer enclosure as a singular ring. In this embodiment, the system 400 may comprise an external heater. In some embodiments, the outer enclosure 492 may function as an external heater. In some embodiments, the external heater is disposed within the outer enclosure 492. In some embodiments, the external heater is disposed exterior to the outer enclosure 492. The external heater may be positioned such that it heats each of the plurality of reaction tubes 101 equally. In some embodiments, the external heating device may be electrically powered. In some embodiments, the external heating device may burn the remaining product feed stream after the product feed stream has been processed and filtered to heat the plurality of reaction tubes 101. In some embodiments, the external heating device is configured to supplement the heating provided to each reaction tube 101 by each internal heating device 140.

[0073] In some embodiments, for example as seen in Figure 4B, the plurality of reaction tubes may be disposed within the outer enclosure as a plurality of rings 494a, 494b. Each ring 494a, 494b may be disposed concentrically or coaxially with the outer enclosure 492.

[0074] In some embodiments, the outlet header, inlet header and power feeder may each mirror the arrangement of the plurality of reaction tubes 101. In some embodiments where the reactions tubes are arranged in a plurality of rings, the outlet header, inlet header, and power feeder may each take the form of a plurality of rings.

[0075] Figure 4C shows an example embodiment of outlet headers 418 in a ring configuration. This configuration may correspond to the reaction tube configuration as seen in Figure 4B. The outer outlet header 418b may correspond to an outer ring 494b of reactions 101, whereas the inner outlet header 418a may correspond to an inner ring 494a of reaction tubes 101. The power feeder and the inlet header may be configured to the outlet header as described above.

[0076] In conventional steam reforming systems, a multi-ring configuration of tubes, as seen in Figure 4B, would not be practical nor serviceable as the external heating would not be able to efficiently provide heating to the internal rings of the system. This configuration as portrayed in Figure 4B may be beneficial for allowing a multi-ring system to be deployed as each tube can be heated, via each internal heating device 140. This configuration as portrayed in Figures 4A and 4B may be beneficial for reducing the amount of space needed for a multiple tube layout. The lack of an external heating device allows each reaction tube 101 to be placed in close proximity to each other.

[0077] Figure 5 shows a schematic view of a process for converting hydrocarbons into hydrogen while reducing the amount of carbon dioxide produced. The system of Figure 5 may include any of the reaction tubes and / or systems described above with reference to Figures 1A-3.

[0078] As seen in Figure 5, a feed stream comprising hydrocarbons is provided, via line 1, to a steam reformer unit 3. In some embodiments, the feed stream comprises light hydrocarbons. In some embodiments, the feed stream comprises compressed natural gas (CNG). In some embodiments, the feed stream may be preheated. Line 2 conveys process steam to line 1 prior to the feed stream entering the steam reformer unit 3. In some embodiments, the process steam from line 2 may serve to at least partially heat the feed stream.

[0079] The mixed feed is then provided to the steam reformer reactor 3. In some embodiments, the steam reformer unit 3 may be similar to the systems 100, 200, 300 described above. The mixed feed is heated and converted over a catalyst to a syngas containing H2, CH4, CO, CO2, and steam. Steam reformer unit 3 is heated, at least partially, by an internal electric heater 4. In some embodiments, the steam reformer unit 3 may be partially enclosed by a process heater 14 which provides additional heating to the steam reformer unit 3.

[0080] Line 5 conveys the syngas from the steam reformer unit 3 to a shift conversion unit 6 wherein some of the CO and steam in the syngas react to form additional th and CO2. Line 7 coveys the shifted syngas from the shift conversion unit 6 to a CO2 removal unit 8. In some embodiments, the CO2 removal unit 8 is a carbon dioxide scrubber wherein carbon dioxide is dissolved in an amine solvent at a first temperature and the solvent is isolated from the syngas and heated to a second temperature at which carbon dioxide comes out of solution in gaseous state. The captured CO2 exits the system via line 9. The separated carbon dioxide may be further compressed for a specific use or for sequestration. The syngas in the CO2 removal unit 8 may be at a pressure of greater than 10 bar. The carbon dioxide may be expelled at a pressure greater than 10 bar. In some embodiments, the carbon dioxide may be expelled at a pressure between 30-60 bar. In some embodiments, approximately 65% of the feed carbon content is expelled via the CO2 removal unit. In some embodiments, approximately 70% of the feed carbon content is expelled via the CO2 removal unit. In some embodiments, greater than 70% of the feed carbon content is expelled via the CO2 removal unit.

[0081] Line 10 conveys the shifted syngas from the CO2 removal unit to a pressure swing adsorption (PSA) unit 11. The PSA unit 11 separates approximately 90% of the hydrogen from the syngas. Line 12 conveys the hydrogen product for further processing. The PSA tail gas is conveyed via line 13 to a process heater 14. The PSA tail gas may include the remaining H2, CH4, CO, and CO2 constituents of the syngas. The process heater 14 may serve as an external heater to steam reformer unit 3, supplementing the internal heating unit 4. The process may burn approximately 35%, approximately 30%, or less than 30% of the remaining feed carbon content. The burned carbon content may escape the process heater 14 in a flue gas in the form of CO2.

[0082] Figure 6 shows a schematic view of another embodiment of a process for converting hydrocarbons into hydrogen while reducing the amount of carbon dioxide produced. Some of the components of Figure 6 may be similar to those described in Figure 5.

[0083] As seen in Figure 6 and similar to Figure 5, a feed stream comprising hydrocarbons is provided, via line 1, to a steam reformer unit 3. In some embodiments, the feed stream comprises light hydrocarbons. In some embodiments, the feed stream comprises compressed natural gas (CNG). In some embodiments, the feed stream may be preheated. In some embodiments, the feed stream does not require preheating. Line 2 conveys process steamto line 1 prior to the feed stream entering the steam reformer unit 3. In some embodiments, the process steam from line 2 may serve to at least partially heat the feed stream.

[0084] The mixed feed is then provided to the steam reformer unit 3. In some embodiments, the steam reformer unit 3 may be similar to the systems 100, 200, 300 described above. The mixed feed is heated and converted over a catalyst to a syngas containing H2, CH4, CO, CO2, and steam. Steam reformer unit 3 is heated, at least partially, by an internal electric heater 4. In some embodiments, the steam reformer unit may be partially enclosed by a process heater 14 which provides additional heating to the steam reformer unit 3.

[0085] Line 5 conveys the syngas from the steam reformer unit 3 to a shift conversion unit 6 wherein some of the CO and steam in the syngas react to form additional H2 and CO2. Line 7 coveys the shifted syngas from the shift conversion unit 6 to a CO2 removal unit 8. In some embodiments, the CO2 removal unit 8 is a carbon dioxide scrubber wherein carbon dioxide is dissolved in an amine solvent at a first temperature and the solvent is isolated from the syngas and heated to a second temperature at which carbon dioxide comes out of solution in gaseous state. The captured CO2 exits the system via line 9. The separated carbon dioxide may be further compressed for a specific use or for sequestration. The syngas in the CO2 removal unit 8 may be at a pressure of greater than 10 bar. The carbon dioxide may be expelled at a pressure greater than 10 bar. In some embodiments, the carbon dioxide may be expelled at a pressure between 30-60 bar.

[0086] Line 10 conveys the syngas from the CO2 removal unit 8 to a pressure swing adsorption (PSA) unit 11. The PSA unit 11 separates approximately 90% of the hydrogen from the syngas. Line 12 conveys the hydrogen product for further processing. The PSA tail gas is conveyed via line 13 to a recycling processing block 15. The PSA tail gas may include the remaining H2, CH4, CO, and CO2 constituents of the syngas.

[0087] The carbon rich constituents of the PSA tail gas are separated from the other constituents of the PSA tail gas, via the recycle processing block 15. The carbon rich constituents are conveyed via line 16 and rejoined with the feed stream being conveyed via line 1. In some embodiments, the carbon rich constituents of the PSA tail gas may include carbon dioxide.

[0088] The remaining constituents are conveyed via line 17 to a process heater 18. The process heater 18 may serve as an external heater to steam reformer unit 3, supplementingthe internal heating unit 4. In some embodiments, a portion of the syngas conveyed via line 10 is redirected via line 14 and combined with the PSA tail gas being conveyed via line 13. In some embodiments, a portion of the PSA tail gas can be rerouted to line 10 to capture a portion of the hydrogen from the first pass through the PSA. Redirecting a portion of the syngas to line 14 may be beneficial in providing hydrogen rich fuel to the process heater 18, thereby reducing the amount of carbon rich fuel needed to fuel the process heater 18.

[0089] This embodiment may be beneficial for reducing the amount of CO2 released in the form of Hue gas. In the first pass, approximately 65%, 70%, or greater than 70% of the carbon content of the feed stream is captured via the CO2 removal unit. Approximately 90%, 92% or greater than 92% of the remaining carbon content is separated via the recycle processing block and reincorporated into the feed stream. Upon reaching steady state, approximately 97% of the carbon content in the feed stream is captured via the CO2 removal unit with approximately only 3% of the carbon content in the feed stream being burned in the process heater and released as CO2.

[0090] Other advantages and other embodiments of the present technology will be obvious to those skilled in the art. Their omission here is not intended to exclude them from the claims advanced herein.

[0091] As used herein, “tube”, “vessel”, “device,” “chamber”, or “equipment” may be used interchangeably without departing from the scope of this application.

[0092] Although the present technology has been described in terms of certain preferred embodiments, various features of separate embodiments can be combined to form additional embodiments not expressly described. Moreover, other embodiments apparent to those of ordinary skill in the art after reading this disclosure are also within the scope of this disclosure. Furthermore, not all the features, aspects and advantages are necessarily required to practice the present technology. Thus, while the above detailed description has shown, described, and pointed out novel features of the present technology as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the apparatus or process illustrated may be made by those of ordinary skill in the technology without departing from the spirit or scope of the present disclosure. The present technology may be embodied in other specific forms not explicitly described herein.The embodiments described above are to be considered in all respects as illustrative only and not restrictive in any manner.

Claims

WHAT IS CLAIMED IS:

1. A steam reforming device comprising: a shell; an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube; a fluid inlet in communication with the annulus; a fluid outlet in communication with the annulus; a catalytic reactor system disposed within the annulus, the catalytic reactor system configured to allow fluid to flow through the annulus; and at least one internal heating device disposed within the inner tube, the at least one internal heating device configured to heat a fluid flowing through the annulus.

2. The device of claim 1, wherein the at least one internal heating device is electrically powered.

3. The device of claim 1, wherein at least a portion of the shell is cylindrical.

4. The device of claim 3, wherein the inner tube is disposed coaxially within the shell.

5. The device of claim 4, wherein the at least one internal heating device is disposed coaxially within the inner tube.

6. The device of claim 1, wherein the at least one internal heating device is disposed with the inner tube such that the at least one internal heating device contacts the inner tube.

7. The device of claim 1, wherein the at least one internal heating device is separated from the inner tube by a central volume.

8. The device of claim 7, further comprising a conductive material disposed within the central volume.

9. The device of claim 1, wherein the at least one internal heating device is configured to release variable amounts of heat along a length of the inner tube .

10. A system comprising: a plurality of reaction tubes, each reaction tube comprising: a shell;an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube; a fluid inlet in communication with the annulus; a fluid outlet in communication with the annulus; a catalytic reactor system disposed within the annulus, the catalytic reactor system configured to allow fluid to flow through the annulus; and at least one internal heating device disposed within the inner tube, the at least one internal heating device configured to heat a fluid flowing through the annulus.

11. The system of claim 10, wherein the plurality of reaction tubes are arranged in at least one row.

12. The system of claim 11, wherein the at least one row comprises a plurality of rows arranged parallel to each other.

13. The system of claim 10, further comprising an external heating device, the external heating device configured to supplement the heating provided by the at least one internal heating device of each reaction tube.

14. The system of claim 13, wherein the external heating device burns a portion of a product stream that has passed through at least one of the plurality of reaction tubes.

15. The system of claim 13, wherein the external heating device is electrically powered.

16. The system of claim 10, wherein the at least one internal heating device is further configured to release variable amounts of heat along a length of each inner tube.

17. The system of claim 16, wherein the at least one internal heating device is configured to independently control the variable amounts of heat released for each inner tube of each reactor tube.

18. A method of steam reforming, the method comprising: providing a fluid feed stream to a reaction device, wherein the reaction device comprises: a shell; an inner tube disposed within the shell such that an annulus is formed between the shell and the inner tube;a catalytic reactor system disposed within the annulus, the catalytic reactor system configured to allow fluid to flow through the annulus; and at least one internal heating device disposed within the inner tube; passing the fluid feed stream over the catalytic reactor system; heating the fluid feed stream, via the at least one internal heating device, as it passes over the catalytic reactor system; reacting the fluid feed stream to form a product stream; extracting a first compound of interest from the product stream; and recycling at least a portion of the product stream back into the reaction device.

19. The method of claim 18, wherein recycling at least a portion of the product stream comprises recycling at least a portion of a second compound of interest extracted from the product stream.

20. The method of claim 18, wherein providing a fluid feed stream comprises providing a mixture of hydrocarbons and steam.

21. The method of claim 18, further comprising separating a carbon-rich stream from the product stream.

22. The method of claim 21, wherein recycling at least a portion of the product stream comprises recycling the separated carbon-rich stream back into the reaction device.

23. The method of claim 18, wherein extracting the first compound of interest comprises extracting carbon dioxide from the product stream.

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