Feeding device to feed reactant gas and catalytic reformer

Abstract

Invention relates to a feeding device (4) to feed / distribute a reactant gas to a catalytic reformer (1), the feeding device (4) comprises: - a number of headers (41) to be extended radially on a feeding area (FA) of the catalytic reformer, inward to a longitudinal center axis (CL) of the catalytic reformer, the number of headers (41) being two, three, four or more; - a number of tubes (42) in flow connection with headers (41) and provided with openings (43) to feed / distribute reactant gas, tubes (42) are extending in a circumferential direction; - tubes (42) are configured to define feeding zones (FZ) wherein a flow rate of the reactant gas in each feeding zone (FZ) is independently controllable. Invention relates also to a catalytic reformer (1).

Description

Feeding device to feed reactant gas and catalytic reformerTechnical field

[0001] The present invention relates to a feeding device to feed I distribute reactant in gas phase in a catalytic reformer. The catalytic reformer is configured to convert hydrocarbon feedstock into product gas. The catalytic reformer may comprise a reactor shell forming an enclosure having a circular / polygonal cross section and defining an interior space for catalyst to be accommodated, a support structure for supporting the catalyst and the feeding device. The present invention relates to an improved reactor system and catalyst configuration for the production of synthesis gas (syngas) from biomass using reactant in gas phase, such as steam and oxygen. The invention specifically concerns an enhanced reactant gas feeding device for a downward-flow type catalytic reformer reactor, designed to improve catalyst stability, thermal efficiency, and syngas yield. Especially the present invention relates to a feeding device according to the preamble of claim 1 and a catalytic reformer according to the preamble of claim 14.Background art

[0002] Catalytic reforming to convert hydrocarbon feedstock into product gas is a well-established process for converting renewable carbonaceous materials into synthesis gas composed primarily of hydrogen (H2), carbon monoxide (CO), and carbon dioxide (CO2). Such gas can be utilized in a wide range of downstream applications including Fischer-Tropsch synthesis, methanol production, and hydrogen generation for fuel cells.

[0003] Conventional reforming reactors are often configured as fluidized-bed, fixed-bed, or entrained-flow systems. Among these, downward-flow configurations — in which biomass and reforming agents in gas phase descend through the reactor under gravity — are advantageous due to improved solids handling, controlled residence time, and facilitated removal of ash or char residues. In such systems, catalytic reforming typically occurs at temperatures between 700 °C and 950 °C, and at pressures ranging from atmospheric to about 10 bar.

[0004] A carefully controlled ratio of steam to carbon (S / C), generally in the range of 0.8 to 2.0 mol / mol, is used to suppress coke formation and drive the reforming reactions. A limited supply of oxygen (or air), controlled by the oxygen-to-carbon (O / C) ratio, typically0.1 to 0.4 mol / mol, provides the necessary heat through partial oxidation reactions. The synthesis gas composition is influenced by these operating parameters as well as by the nature and performance of the catalyst system.

[0005] Known catalytic systems typically utilize nickel (Ni) or noble metal-based catalysts (e.g., Rh, Pt) supported on thermally stable materials such as alumina, zirconia, or cerium oxide, sometimes promoted with alkali or alkaline earth metals to enhance resistance to deactivation. These catalysts facilitate endothermic steam reforming reactions as well as exothermic partial oxidation and water-gas shift reactions.

[0006] An object of the invention is to provide a feeding device for catalytic reformer and a catalytic reformer in which the performance is considerably improved compared to the prior art solutions.Disclosure of the Invention

[0007] Objects of the invention can be met substantially as is disclosed in the independent claim and in the other claims describing more details of different embodiments of the invention.

[0008] According to an embodiment it is provided a feeding device to feed I distribute reactant in gas phase to a catalytic reformer. The reactant in gas phase comprises one or more reforming agents, including steam and / or CO2, and may further comprise an oxidizing agent, such as oxygen. The reactant in gas phase preferably comprises a mixture of oxygen and steam, ora mixture of oxygen, steam and CO2. Hereinafter, the reactant in gas phase is referred to as reactant gas. The feeding device comprises: - a number of headers extending radially on a feeding area of the catalytic reformer, inward to a longitudinal center axis of the catalytic reform er, the number of headers being two, three, four or more;- a number of tubes in flow connection with headers and provided with openings to feed I distribute reactant gas, tubes are extending in a circumferential direction;- tubes are configured to define feeding zones wherein a flow rate of the reactant gas in each feeding zone is independently controllable.

[0009] According to an embodiment it is provided a catalytic reform er to convert hydrocarbon feedstock into product gas, the catalytic reformer comprising a reactor shellforming an enclosure having a circular / polygonal cross section and defining an interior space for catalyst to be accommodated, a support structure for supporting the catalyst and the feeding device.

[0010] In the above disclosed embodiments of the feeding device and the catalytic reformer are provided to convert hydrocarbon feedstock into product gas, such as in gasification to convert biomass for example to aviation fuels. The catalytic reformer comprises a reactor shell forming an enclosure having a circular / polygonal cross section and defining an interior space for catalyst to be accommodated. The circular / polygonal cross section is a suitable shape to enable controllable process in the interior space of the reactor shell. To enable catalyst reaction, reactant gas, preferably oxygen and steam are mixed and fed into gas flow on top of catalyst layer laying on a support structure for supporting the catalyst. The purpose of the feeding device is to feed I distribute reactant gas to a feeding area of the catalytic reformer. Feeding of reactant gas is done with multiple headers. Thus, according to the present embodiment, a number of headers are extending radially, inward to a longitudinal center axis of the catalytic reformer, the number of headers being two, three, four or more. In flow connection with headers there are a number of tubes provided with openings to feed I distribute reactant gas. Tubes are extending in a circumferential direction. The tubes have been set on a variety of radiuses so that tubes form a coaxial configuration that is connected to headers. Headers feed reactant gas to tubes and tubes have holes at lower surfaces as reactant gas outlet. Holes are to be drilled in pattern and size that produce acceptably even distribution. To enable better adjustment, reactant gas can be only fed to a certain section of tubes from one header. T ubes are configured to define feeding zones wherein a flow rate of the reactant gas in each feeding zone is independently controllable.This allows precise control and even distribution of feeding in individual sectors or annular-shaped feeding zones as a coaxial configuration. Tubes are preferably welded to headers as to provide rigidity to the feeding device structure. In a centre area, an additional nozzle tube can be added to the header end, if necessary.

[0011] The above explained feeding device provides an effect by means of which the performance of the catalytic reformer is considerably improved. Especially the controllability is improved for various load situations and the construction is simple yet rigid, long-lasting at all relevant operating temperatures.

[0012] According to an embodiment the feeding area partitioned into feeding zones by the headers. This provides an effect that the partitioning can be done in a simple and effective way. It also enables easy controllability and response to different processconditions and possible variations in different areas of the ongoing process on the catalyst support.

[0013] According to an embodiment tubes that are in flow connection with one header formsone independently controllable feeding zone in a coaxial configuration. In this embodiment the tube is in flow connection with only one header and the other headers are bypassed without flow connection, the tube is just mechanically supported by the other bypassed headers. This enables a configuration, where there are coaxial, annularshaped feeding zones. The number of feeding zones depends on the number of headers, for example if there are three headers, there may be three annular-shaped, coaxial independently controllable feeding zones. If there are four headers, there may be four coaxial independently controllable feeding zones.

[0014] According to an embodiment each tube is divided in sectors by a stopper / s to configure a tube sector so that each tube sector is in flow connection with one header. Sectors may be arranged between each two adjacent headers. This feature has an effect that the flow rate at each tube sector can be reliable determined and adjusted. In a case where there would be two headers in flow connection with one tube sector, the oxygen -steam feeding would find its balance in terms of feeding pressure, flow resistance or pressure difference between different headers. That may have some complications in feeding reliability, therefore this division by stoppers has been considered as a preferred option.

[0015] According to an embodiment the stopper is provided between two adjacent headers. There are a couple of alternatives to accomplish the previously discussed stopper configuration. One is to provide a stopper somewhere between two adjacent headers, here the preferred configuration is the half way between the headers, meaning that the tube sector is equally long from both adjacent headers and the stopper is in the middle. According to an embodiment the stopper is the adjacent header. This is the second alternative for the stopper configuration. The tube sector is open only from one end while the other end is a dead end, only welded to the following header.

[0016] According to an embodiment tube sectors that are in flow connection with one header forms one independently controllable feeding zone. By means of controllability, this is the most convenient way to control the feeding. As the operational conditions within the reactor shell are harsh, the steering device, such as a valve or like, is most suitably located outside the reactor shell.

[0017] According to an embodiment a flow rate of each header is independently controllable. By means of controllability, this is the most convenient way to control the feeding. As the operational conditions within the reactor shell are harsh, a control device affecting in particular to the flow rate is especially practical in use. Such device, such as a header valve or like, is most suitably located outside the reactor shell where the conditions are much easier, for example in terms of temperature and corrosive atmosphere.

[0018] According to an embodiment tubes comprise openings pointing downwards to feed / distribute reactant gas. This is the preferred design, the reactant gas flows directly toward the catalyst. This has been found to be the most effective design. It is possible to have also openings pointing somewhere else than downwards, but the effectivity of the reactant gas feed may be reduced. In the present embodiment pointing downwards has naturally some tolerance, it does not need to be exactly downwards, but within a range of downwards preferably ±15°, ±30° or even ±45° is still to be considered pointing downwards. The opening may also be provided with a nozzle to affect on a flow pattern of the opening.

[0019] According to an embodiment the openings are dimensioned in size and spaced circumferentially in a pattern that provides a predetermined distribution of reactant gas. As the process operating parameters, feedstock volume, delay time, etc. determines the need of reactant gas, the feeding device need to be designed accordingly.

[0020] According to an embodiment tubes are spaced radially apart from one another and substantially concentrically surround the longitudinal center axis of the catalytic reformer. The effect of this feature is to enable even distribution of the reactant gas and simultaneously provide a structure of a reasonable stiffness that is still cost effective if looked from a manufacturing point of view.

[0021] According to an embodiment the headers are configured as manifolds to comprise constant or variable cross-sectional flow area, such as decreasing cross sectional toward the longitudinal center axis of the catalytic reformer. The effect of this feature is to enable even distribution and flow conditions within the headers. The headers have a determined length and number of attached tube sectors / circumferential zones I openings at tubes. The flow conditions need to be calculated and headers dimensioned so that the reactant gas distribution is even at a requested accuracy.

[0022] According to an embodiment the headers comprise openings or nozzles to feed I distribute reactant gas to a central area of the feeding area of the catalytic reformer. Headers extending radially, inward to the central are around the longitudinal center axisof the catalytic reformer, may be joined together or not by the longitudinal center axis. Depending on the construction, a nearest tube may be at a distance that is too far from this central area. Therefore it may be easiest to provide a suitable opening for feeding reactant gas directly to the header. An opening having distinct flow characteristic may be formed as a nozzle.

[0023] According to an embodiment the catalytic reform er com prises a number of feeding devices, the number of the feeding devices corresponds to the number of support structures for supporting the catalyst. A general construction of the catalytic reformer may be a multi stage reactor wherein there are multiple support structures and feeding devices in an array. If that is the case, then this feature is among preferred embodiments.

[0024] The exemplary embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used in this patent application as an open limitation that does not exclude the existence of also unrecited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims.Brief Description of Drawings

[0025] In the following, the invention will be described with reference to the accompanying exemplary, schematic drawings, in whichFigure 1 illustrates a cross sectional overview of a catalytic reformer,Figure 2 illustrates an isometric cross section of a subsequence of a catalytic reformer according to an embodiment of the invention,Figure 3 illustrates a feeding device according to still another embodiment of the invention,Figure 4A and 4B illustrates a feeding devices according to still another embodiments of the invention,Figure 5A and 5B illustrates a feeding devices according to still another embodiments of the invention.Detailed Description of Drawings

[0026] Figure 1 depicts schematically a cross section of a catalytic reformer 1 to convert hydrocarbon feedstock into product gas, the catalytic reformer 1 comprising a reactor shell 2 forming an enclosure having a circular / polygonal cross section and defining an interior space for catalyst to be accommodated, a support structure 3 for supporting the catalyst and a feeding device 4 to feed I distribute reactant gas to a feeding area FA of the catalyticreformer. A numberof headers 41 are extending radially on the feeding area FA of the catalytic reformer, inward to a longitudinal center axis CL of the catalytic reform er 1. The catalytic reform er 1 com prises a num ber of feeding devices 4, the num ber of the feeding devices 4 corresponds to the num ber of support structures 3 for supporting the catalyst. The feeding device comprises a numberof tubes 42 in flow connection with headers 41 and provided with openings 43 to feed I distribute reactant gas, tubes 42 are extending in a circumferential direction and being arranged for exam pie between each two adjacent headers 41.

[0027] Figure 2 depicts schematically an isometric cross section of a subsequence of the catalytic reformer 1 presented in Figure 1. The feeding device 4 feeds / distributes reactant gas to a feeding area FA of the catalytic reformer. In this embodiment the feeding area FA corresponds the whole circular cross section of the reactor shell 2. The feeding device 4 comprises:- a number of headers 41 extending radially on the feeding area FA of the catalytic reformer, inward to a longitudinal center axis CL of the catalytic reformer 1 , the number of headers 41 being two, three, four or more;- a number of tubes 42 in flow connection with headers 41 and provided with openings 43 (not visible in this FIG. 2 ) to feed I distribute reactant gas, openings 43 are pointing downwards toward the support structure 3, preferably the openings 43 are dimensioned in size and spaced circumferentially in a pattern that provides a predetermined distribution of reactant gas. Tubes 42 are extending in a circumferential direction and being arranged between each two adjacent headers 41 ; tubes 42 are configured to define feeding zones FZ wherein a flow rate of the reactant gas in each feeding zone FZ is independently controllable. Tubes 42 are spaced radially apart from one another and substantially concentrically surround the longitudinal center axis CL of the catalyticreformer1. Here in this embodiment one of the feeding zones FZ is presented as one 1 / 3 circle sector of the whole feeding area FA, shown as between two dashed lines on headers 41. The support structure 3 for supporting the catalyst is configured in the reactor shell 2 forming an enclosure having a circular / polygonal cross section and defining an interior space for catalyst to be accommodated.

[0028] Figure 3 depicts schematically a top cross section view of a feeding device 4 to feed I distribute reactant gas to a feeding area FA of the catalytic reformer, the feeding device 4 comprises:- A number of headers 41 extending radially, inward to a longitudinal center axis CL of the catalytic reformer 1, the number of headers 41 being two, three, four or more. The headers preferably extend from outside through a shell wall 20 and an insulation 21 into the interior space of the reactor shell 2.- A number of tubes 42 in flow connection with headers 41 and provided with openings 43 to feed / distribute reactant gas. Here the openings are not illustrated since they point to the opposite direction. Tubes 42 are extending in a circumferential direction and being arranged between each two adjacent headers 41. In more detail, tubes 42 are spaced radially apart from one another and substantially concentrically surround the longitudinal center axis CL of the catalytic reformer 1.- Tubes 42 are configured to define feeding zones FZ wherein a flow rate of the reactant gas in each feeding zone FZ is independently controllable. In this embodiment headers 41 are provided with header valves 410 to perform the independent controllability. The header valves 410 are preferably outside the reactor shell as the operating conditions, temperature, corrosion, etc. are much easier. According to an embodiment (not shown in FIG. 3) the headers 41 are configured as manifolds to comprise constant or variable cross-sectional flow area, such as decreasing cross sectional toward the longitudinal center axis CL of the catalytic reformer 1. Also the headers 41 may comprise openings or nozzles 43 or some other arrangement to feed I distribute reactant gas to the central area of the feeding area FA of the catalytic reformer 1.

[0029] Figure 4A and Figure 4B depicts schematically a top cross section view of a feeding device 4 similar to in Figure 3. The feeding device 4 comprises number of tubes 42 in flow connection with headers 41 for feeding I distributing reactant gas. Tubes 42 are extending in a circumferential direction and being arranged between each two adjacent headers 41. In more detail, tubes 42 are spaced radially apart from one another and substantially concentrically surround the longitudinal center axis CL of the catalytic reformer 1. The main difference between embodiments of FIG. 4A and FIG. 4B is theconfiguration of feeding zone FZ. In both embodiments tubes 42 are configured to define feeding zones FZ wherein a flow rate of the reactant gas in each feeding zone FZ is independently controllable. Here the feeding zones are illustrated with radially illustrated dashed lines so that each tube 42 is divided in sectors 421 by a stopper / s 422 to configure a tube sector 421 so that each tube sector 421 is in flow connection with one header 41. In other way around, tube sectors 421 that are in flow connection with one header 41 form sone independently controllable feeding zone FZ. In the embodiment of FIG. 4A the stopper 422 is the adjacent header 41. In the embodiment of FIG. 4B the stopper 422 is provided between two adjacent headers 41.

[0030] Figure 5A and 5B illustrates feeding devices according to still another embodiments of the invention, both Figures 5A and 5B showing embodiment wherein the feeding area FA is partitioned into feeding zones FZ by the headers 411, 412, 413, 414. Here tubes (not shown) that are in flow connection with one header 411, 412, 413, 414 forms one annular-shaped independently controllable feeding zone FZ1 , FZ2, FZ3, FZ4 in a coaxial configuration i.e. the feeding zones are circle I polygonal shaped around the innermost circular / polygonal feeding zone. Here the terms circular, circle / polygonal are only descriptive, not bound to a mathematic shape of the term. The number of feeding zones depends on the number of headers, for example in the FIG 5A there are three headers 411, 412, 413, that conf igures three coaxial independently controllable feeding zones FZ1, FZ2 FZ3. In these embodiments tubes are in flow connection with only one header and the other headers are bypassed without flow connection. However, tubes are mechanically supported by the other bypassed headers to provide a suitable mechanical rigidity forthe tubes and the feeding device. This enables a configuration, where there are annular-shaped, coaxial feeding zones. Reactant gas feeding to tubes is illustrated here in these FIG 5A and 5B with arrows, headers 411 deliver reactant gas to feeding zone FZ1, headers 412 deliver reactant gas to feeding zone FZ2, headers 413 deliver reactant gas to feeding zone FZ3 and header 414 deliver Reactant gas to feeding zone FZ4. Depending on the flow conditions inside the reactor shell, this coaxial configuration may have some advantages over embodiments having feeding zones in sectors (as disclosed earlier in connection with FIG 4A and 4B) In the embodiment of FIG. 5B there is illustrated an embodiment with four headers 411, 412, 413, 414, providing four coaxial independently controllable feeding zones FZ1, FZ2, FZ3, FZ4. This embodiment provides even further possibilities to have increased precision in controlling the catalytic reforming process.

[0031] In the above description of drawings, the terms “upper”, “lower”, “on top”, “below”, “upward”, and “downward” relate to the above-mentioned, intended positions in the position shown in the figures. In this description, the singular form “a”, “an”, and “the” referring to a device or component does not exclude additional or a plurality of corresponding devices or components, unless where specifically specified. In the description, various devices and components may be described as “comprising” other components. The terms “com prise(s)”, “comprising”, “include(s)”, “having”, “has”, and variants thereof , are intended to be open- ended phrases that do not exclude the possibility of additional components, unless where specifically specified.

[0032] While the invention has been described herein by way of examples in connection with what are, at present, considered to be the most preferred embodiments, it is obvious to the skilled person that, along with the technical progress, the basic idea of the invention can be implemented in many ways. The invention and its embodiments are thus not limited to the examples and samples described above but they may vary within the contents of patent claims and their legal equivalents. The details mentioned in connection with any embodiment above may be used in connection with another embodiment when such combination is technically feasible.Reference number list1 catalytic reformer2 reactor shell20 shell wall21 insulation3 support structure4 feeding device41 header410 header valve411, 412, 413, 414 header42 tube421 tube sector422 stopper43 openingFA feeding areaFZ feeding zoneFZ1 feeding zone FZ2 feeding zone FZ3 feeding zone FZ4 feeding zone CL center axis

Claims

Claims1. A feeding device (4) to feed I distribute a reactant gas to a catalytic reformer (1), characterized in that the feeding device (4) comprises:- a number of headers (41) to be extended radially on a feeding area (FA) of the catalytic reformer, inward to a longitudinal center axis (CL) of the catalytic reformer, the number of headers (41) being two, three, four or more;- a number of tubes (42) in flow connection with headers (41) and provided with openings (43) to feed I distribute reactant gas, tubes (42) are extending in a circumferential direction;- tubes (42) are configured to define feeding zones (FZ) wherein a flow rate of the reactant gas in each feeding zone (FZ) is independently controllable.

2. A feeding device (4) according to claim 1 , characterized in that the feeding area (FA) is partitioned into feeding zones (FZ) by the headers (41).

3. A feeding device (4) according to claim 1 or 2, characterized in that tubes (421) that are in flow connection with one header (41) form one annular-shaped independently controllable feeding zone (FZ, FZ1 , FZ2, FZ3, FZ4) in a coaxial configuration.

4. A feeding device (4) according to claim 1 or 2, characterized in that each tube (42) is divided in sectors (421) by a stopper / s (422) to configure a tube sector (421) so that each tube sector (421) is in flow connection with one header (41).

5. A feeding device (4) according to claim 4, characterized in that the stopper (422) is provided between two adjacent headers (41).

6. A feeding device (4) according to claim 4, characterized in that the stopper (422) is the adjacent header (41).

7. A feeding device (4) according to any of claims 4-6, characterized in that tube sectors (421) that are in flow connection with one header (41) form one independently controllable feeding zone (FZ).

8. A feeding device (4) according to any of the preceding claims, characterized in that flow rate of each header (41) is independently controllable.

9. A feeding device (4) according to any of the preceding claims, characterized in that tubes (42) comprise openings (43) to be pointed toward catalyst.

10. A feeding device (4) according to any of the preceding claims, characterized in that the openings (43) are dimensioned in size and spaced circumferentially in a pattern that provides a predetermined distribution of reactant gas.

11. A feeding device (4) according to any of the preceding claims, characterized in that tubes (42) are spaced radially apart from one another and substantially concentrically surround the longitudinal center axis (CL) of the catalytic reformer (1).

12. A feeding device (4) according to any of the preceding claims, characterized in that the headers (41) are configured as manifolds to comprise constant or variable cross-sectional flow area, such as decreasing cross sectional toward the longitudinal center axis (CL) of the catalytic reformer (1).

13. A feeding device (4) according to any of the preceding claims, characterized in that the headers (41) comprise openings or nozzles (43) to feed / distribute reactant gas to a central area of the feeding area (FA) of the catalytic reformer (1).

14. A catalytic reformer (1) to convert hydrocarbon feedstock into product gas, the catalytic reform er (1) comprising a reactor shell (2) forming an enclosure having a circular / polygonal cross section and defining an interior space for catalyst to be accommodated, a support structure (3) for supporting the catalyst and the feeding device (4) according to any of the preceding claims.

15. A catalytic reformer (1) according to claim 14, characterized in that the catalytic reformer (1) comprises a number of feeding devices (4), the number of the feeding devices (4) corresponds to the number of support structures (3) for supporting the catalyst.

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