Axial-modified pipe

Abstract

In the axial reforming tube of the present invention, at least a portion of the inner surface of the reforming tube has a rough surface portion having an arithmetic mean roughness Ra of 12.5 μm or more and 500 μm or less, the axial reforming tube extends along its axial length, and the rough surface portion has a circumferential groove pattern.

Description

Technical Field

[0001] The present invention relates to an axial reforming tube, and more specifically to an axial reforming tube for steam methane reforming, but is not limited thereto.

Background Art

[0002] Steam methane reforming is a process widely used in the production of hydrogen from natural gas. For example, steam and methane are heated to 700 degrees to 1000 degrees and 3 bar to 40 bar, pass over a nickel catalyst, and a highly endothermic steam methane reforming reaction (the following "Chemical Formula 1") produces hydrogen, carbon monoxide, and some carbon dioxide. Through the water gas shift reaction with moderate heat generation (the following "Chemical Formula 2"), carbon monoxide and water react on the catalyst to produce carbon dioxide and further hydrogen. Next, carbon dioxide is absorbed by pressure swing absorption, leaving substantially pure hydrogen.

[0003]

Chem.

Chem.

[0004] Steam methane reforming is usually carried out in an axial reforming tube (also called a reforming tube, reformer tube, axial reforming tube, reforming catalyst tube, or reformer). Axial reforming tubes are also used in other reforming processes such as the production of ammonia and methanol.

[0005] When in use, reforming tubes for steam methane reforming are typically oriented vertically within a furnace (a refractory-lined box). Axial reforming tubes made of alloy steel are commonly used to withstand the pressure and temperature required for reforming and to allow for rapid heat transfer from an external heat source through the walls of the reforming tube to the gas flowing along the tube. An example material used in the manufacture of axial reforming tubes is Paralloy's heat-resistant austenitic stainless steel H39WM, which contains 0.4% carbon, 25% chromium, 35% nickel, and 1% niobium.

[0006] To increase the strength of axial reforming pipes and to improve the ratio of internal surface area to volume for heat transfer between the inner surface of the reforming pipe and the gas flowing along it, axial reforming pipes are typically made longer relative to their inner diameter. For example, a reforming pipe with an inner diameter of 10 cm may have a length of 13 m.

[0007] During use, the gas flows generally axially along the axial reforming tube. The steam methane reforming reaction occurs where the reagent gas passes over the catalyst, with the gas flowing along the reforming tube passing around it. The gas also flows along the inner surface of the reforming tube.

[0008] Catalysts are typically shaped to favorably have a high surface area-to-volume ratio, resulting in a relatively low pressure drop (pressure loss) in the gas flowing through the catalyst bed.

[0009] Axial reforming tubes are typically manufactured by spin casting, and the inner surface of the reforming tube is formed by smooth boring, resulting in an arithmetic mean roughness (Ra) of, for example, 3.2 μm to 1.6 μm. This arithmetic mean roughness corresponds to an Rt roughness of 13 μm to 6.3 μm (where Rt is the range of roughness data points collected). Conventionally, boring to create a smooth inner surface of the reforming tube is considered desirable in order to reduce the pressure drop along the reforming tube by reducing resistance to gas flow along the inner surface of the reforming tube, thereby maximizing the yield of reformed gas products. [Overview of the project]

[0010] This disclosure provides an axially modified pipe and a modification system as described in the attached claims.

[0011] According to the first embodiment, at least a portion of the inner surface of the axially modified tube has a roughened surface portion having an arithmetic mean roughness of 12.5 μm or more and 500 μm or less, the axially modified tube extends along the axial length, and the roughened surface portion ,groove The pattern The grooves on the inner surface of the axially modified tube are offset from the circumferential direction by 10 degrees or less. An axially modified pipe is provided.

[0012] According to a second embodiment, a modification system is provided that includes an axial modification pipe according to the first embodiment.

[0013] The inner surface of the roughened portion may have an arithmetic mean roughness of at least 25 μm. The inner surface of the roughened portion may have an arithmetic mean roughness of at least 50 μm. The inner surface of the roughened portion may have an arithmetic mean roughness of at least 100 μm.

[0015] The front of the inner surface of the axially modified tube from the circumferential direction Marking groove This can be 5 degrees or less.

[0016] The pattern of the circumferential groove may be formed as one or more helical grooves.

[0017] The side surface of the circumferential groove may be inclined by a lateral angle between 0 and 50 degrees with respect to a plane perpendicular to the axial length. The side surface of the circumferential groove may be inclined by a lateral angle between 0 and 30 degrees with respect to a plane perpendicular to the axial length. The lateral angle may be at least 10 degrees. The lateral angle may be 25 degrees or less.

[0018] The axial length of the bottom of the circumferential groove may be 50% or more and 200% or less of the depth of the circumferential groove.

[0019] The adjacent circumferential grooves may be separated from each other by the top surface portion (crown portion), and the axial length of the top surface portion may be 50% or more and 100% or less of the depth of the circumferential groove.

[0020] The adjacent circumferential grooves may be separated from each other by the top surface portion, a sharp edge may be formed between the top surface portion and the side surface of the circumferential groove, and the sharp edge may have an average curvature radius of 20 μm or less.

[0021] The rough surface portion may extend over the entire length of the axially modified tube.

[0022] The axially modified tube may have an arithmetic mean roughness of 3.2 μm or less and include a smooth surface portion bonded to the rough surface portion.

[0023] The rough surface portion may be bonded between the two smooth surface portions.

[0024] The axially modified tube may have a length of at least 700 mm.

[0025] The inner diameter of the axially modified tube may be 350 mm or less.

[0026] The axially modified tube may have a length of at least 700 mm, and the inner diameter of the axially modified tube may be 95 mm or more and 280 mm or less. [[ID=三十]]

[0027] The axially modified tube may have a length of at least 2 meters. The inner diameter of the axially modified tube may be 95 mm or more and 250 mm or less.

[0028] The reforming system may further include a catalyst bed filled in at least a part of the axially modified tube, a heater that heats at least a part of the axially modified tube, a pump that feeds gas through the catalyst bed, and a control system that monitors and controls the operation of the reforming system.

Brief Description of the Drawings

[0029] Examples will be further described with reference to the attached drawings below.

[0030] [Figure 1A] This shows an axially modified pipe. [Figure 1B] Figure 1A shows a cross-sectional view of a portion of the axially modified pipe. [Figure 1C] This shows a photograph of a portion of the interior of an axially modified pipe. [Figure 1D] This diagram shows a portion of the interior of an axially modified pipe. [Figure 2] This shows an example of gas flow across the inner surface of an axial reforming pipe. [Figure 3] Another axially modified pipe is shown. [Figure 4] This shows the modification system. [Figure 5A] This shows the heat transfer coefficients in three axially modified tubes with different internal surface roughness. [Figure 5B] This shows the pressure drop in three axially modified tubes with different internal surface roughness. [Figure 6] This graph shows experimental results illustrating the heat transfer coefficient for different values ​​of internal surface roughness. [Figure 7A] The simulation plots of gas temperature along the central plane of two different axial reforming pipes are shown. [Figure 7B] The simulation plots of gas temperature along the central plane of two different axial reforming pipes are shown. [Modes for carrying out the invention]

[0031] Throughout this specification, similar reference numerals refer to the same elements.

[0032] Figure 1A shows an axial reforming pipe 100 for use in a generally axial gas flow F (the catalyst is not shown for illustrative purposes), and Figure 1B shows a magnified view of region B shown in Figure 1A.

[0033] The axial reforming tube 100 has an axial length that is much longer than its inner diameter. The axial reforming tube may be hollow cylindrical. During use, the gas flow F will pass around the catalyst within the reforming tube, but overall it is axial along the length of the reforming tube 100, as shown by line AA in Figure 1A.

[0034] The inner surface 110 of the wall of the axial reforming pipe 100 has an Ra roughness of at least 12.5 μm. Here, Ra roughness is the arithmetic mean roughness of the surface (e.g., an Rt roughness of at least 50 μm). Such roughness of the inner surface of the axial reforming pipe alters the gas flow along the inner surface of the axial reforming pipe compared to a smooth inner surface. As a result, turbulence is generated, preventing the formation of a boundary layer and laminar flow along the inner surface of the pipe wall. This turbulence promotes heat transfer from the pipe wall to the gas flowing inside the reforming pipe. By providing an Ra roughness of at least 12.5 μm on the inner surface 110 of the pipe wall, heat transfer is significantly improved, and by providing an Ra roughness of at least 25 μm on the inner surface 110 of the pipe wall, heat transfer can be improved by approximately 10%. In these cases, the effect on the pressure drop (pressure loss) of the gas flowing along the reforming pipe is minimal. This improvement in heat transfer coefficient can improve the efficiency of the steam methane reforming reaction. The inventors of this application have confirmed that the advantage of improved heat transfer due to the above-mentioned surface roughness outweighs the effect of increased aerodynamic resistance due to the induction of turbulence along the inner surface of the pipe wall.

[0035] The inner surface 110 of the pipe wall has an Ra roughness of 500 μm or less (for example, an Rt roughness of 2000 μm or less). Limiting the Ra roughness to 500 μm or less promotes the mixing of turbulence generated by the rough surface shape with the gas flow away from the inner surface. As a result, turbulence does not remain separately within the depth of the rough surface shape (for example, at the bottom of the groove 112), but rather heat transfer from the pipe wall is enhanced.

[0036] As shown in Figures 1B, 1C, and 1D, the roughness of the inner surface of the pipe wall is formed as a pattern of multiple grooves (circumferential grooves) 112 extending generally in the circumferential direction and multiple raised portions 114. Figure 1D shows the inner surface of a portion of the axially modified pipe 100 (the portion extending from the end 102 of the modified pipe) as viewed radially outward from the central axis of the modified pipe (line AA in Figure 1A). The grooves 112 are at an angle of 10 degrees or less, or 5 degrees or less, from the circumferential direction (direction perpendicular to the axial direction). Noz The groove may extend around the inner surface of the modified pipe with a deviation of φ (angle of deviation viewed from the radial direction). Noz When the angle deviation (angle deviation viewed from the radial direction) φ is small, the formation of turbulent swirling flow 182 within the groove 112 is promoted, as shown in Figure 2. As a result, instead of the gas being swept out of the groove, a gas flow extending almost perpendicularly across each groove 112 is maintained, and the formation of turbulent swirling flow within the groove 112 is prevented.

[0037] As shown in Figure 1C, for example, the roughness of the inner surface 110 of the modified pipe 100 may be provided by one or more helical grooves 112 provided on the inner surface 110 of the modified pipe 100 (for example, by cutting). By cutting the helical grooves 112, roughness can be provided to the inner surface 110 of the modified pipe 100 while reducing the complexity of manufacturing.

[0038] Alternatively, the groove 112 may extend in the circumferential direction (perpendicular to the axial length of the modified pipe 100). For example, the groove 112 may be cut into a flat strip of material (e.g., steel). In this case, the groove 112 is cut perpendicular to the length of the strip before the strip is rounded across its width to form the modified pipe 100 and both ends are sealed (e.g., by welding).

[0039] Figure 2 shows a model of gas 180 flowing axially along the inner surface 110 of the axially reformed pipe 100. A turbulent swirling flow 182 of the gas flow is generated within the groove 112, which increases the rate at which heat is extracted from the pipe wall compared to a smooth inner surface.

[0040] The depth d of the groove 112 and raised portion 114 patterns is equal to the amplitude of the roughness of the inner surface 110 and is specified, for example, by an Rt roughness of 50 μm to 2000 μm (e.g., an Ra roughness of 12.5 μm to 500 μm). The axial length L1 of the top surface (crown portion) of the raised portion 114 may be 50% to 100% of the groove depth d. The axial length L2 of the bottom of the groove 112 may be 50% to 200% of the groove depth d. By providing a bottom of the groove 112 with an axial length L2 of 50% to 200% of the groove depth d, the formation of turbulent swirling flow 182 within the groove 112 is promoted. If the bottom of the groove 112 is narrower than this range, the size and formation of turbulent swirling flow 182 within the groove 112 may be limited. If the bottom of the groove 112 is wider than the range in question, the formation of turbulent swirling flow 182 can be reduced as laminar flow can extend into the groove 112.

[0041] The sides 116A and 116B of the groove 112 and raised portion 114 patterns generally face toward both ends of the modified pipe 100. The sides 116A and 116B may have perpendiculars substantially parallel to the axial length of the modified pipe 100, i.e., they may have substantially 0-degree side angles θ1 and θ2 (for example, when the sides of a helical groove are angled only by the pitch of the helical groove). Alternatively, as shown in Figures 1B, 1C, and 2, the side angles θ1 and θ2 of the sides 116A and 116B of the groove 112 and raised portion 114 patterns may not be zero. For example, each side 116A and 116B may be angled by side angles θ1 and θ2 of 50 degrees or less (preferably 30 degrees or less), providing a thread angle (θ1 + θ2) of 100 degrees or less (preferably 60 degrees or less). For example, the sides 116A and 116B may each be angled with respect to the plane perpendicular to the longitudinal direction of the reformed pipe 100 by a side angle θ1 and θ2 greater than 0 degrees (for example, 50 degrees or less or 30 degrees or less). In Figure 2, the depth d is 200 μm, and the side angles θ1 and θ2 of the sides 116A and 116B are 15 degrees, respectively. By angling the sides 116A and 116B by a side angle θ1 and θ2 of at least 10 degrees, the generation of turbulent swirling flow 182 is promoted not in deeper parts of the groove 112, but rather closer to the top of the groove 112 (i.e., closer to the center of the reformed pipe 100). This strengthens the interaction between the turbulent swirling flow 182 and the adjacent, generally axial gas flow F, improving heat transfer from the pipe wall and the gas flow F away from the pipe wall. When angles θ1 and θ2 of 50 degrees or less (preferably 30 degrees or less) are applied to the sides 116A and 116B of the groove 112, the generation of turbulent swirling flow 182 within the groove 112 is promoted while laminar flow passing through the groove 112 is reduced, thereby promoting heat transfer from the pipe wall to the main gas flow F.

[0042] The edges 118A and 118B of the top surface of the raised portion 114 may be sharp. The sharpness of the edges 118A and 118B promotes the formation of turbulence in the gas flowing over the edges 118A and 118B, thereby disrupting the laminar flow and generating a turbulent swirling flow 182 within the groove 112. The sharp edges 118A and 118B may have an average radius of curvature of less than 20 μm.

[0043] Due to the roughness of the inner surface 110 of the axially modified pipe 100, the inner surface area of ​​the modified pipe 100 is increased compared to a pipe that has been smoothly bored. As a result, the surface area that can transfer heat to the gas flow F inside the modified pipe 100 is increased, thereby improving the heat transfer coefficient from the pipe wall to the gas flow F.

[0044] The axially modified pipe 100 in Figure 1A is shown as a single section (partition) having a roughened surface (for example, a pattern of grooves and ridges like a helical screw) that extends along the entire length of the inner surface of the modified pipe 100.

[0045] Alternatively, as shown in Figure 3, a portion of the modified pipe 100' may be formed as a roughened portion 100B' having a roughness pattern, and the other portion of the modified pipe 100' may be formed as smoothed portions 100A', 100C' having a smooth inner surface. For example, as shown in Figure 3, a roughened portion 100B' may be provided between two smoothed portions 110A', 110C'. Each portion of the modified pipe 100' (e.g., smoothed portions 110A', 110C' and roughened portion 100B') may have a length of several meters (e.g., at least 2 meters). For example, the modified pipe 100' may have a roughened portion with an inner surface Ra roughness of 12.5 μm to 500 μm and one or two smoothed portions with a smooth inner surface (Ra roughness of 3.2 μm or less). Roughened surfaces may be provided on all or part of the portion of the reforming pipe 100' filled with the catalyst bed CAT (Figure 4), thereby promoting heat transfer from the pipe wall to the gas flow F that flows through the catalyst and generally along the reforming pipe 100'. Smooth surfaces may also be provided in one or more regions where there is no catalyst, or in regions of the catalyst bed where enhanced heat transfer is not required. Enhanced heat transfer in the roughened sections of the reforming pipe 100' can improve reaction performance. The regions where heat transfer is enhanced may be aligned with the most endothermic reaction in the axial reforming pipe (e.g., a specific portion of the catalyst bed). By providing smooth surfaces on other parts of the axial reforming pipe 100, aerodynamic resistance to the gas flow F through the axial reforming pipe 100 can be reduced, potentially lowering manufacturing complexity and associated costs.

[0046] The axially modified pipe is many times longer than its inner diameter. The axially modified pipe may have a length of several meters. For example, the length of the axially modified pipe may be at least 700 mm, at least 2 m, or at least 5 m. Furthermore, the length of the axially modified pipe may be between 8 m and 13 m. The axially modified pipe may have an inner diameter much smaller than 1 meter. For example, the inner diameter of the axially modified pipe may be 350 mm or less, 95 mm to 280 mm, 95 mm to 250 mm, or 95 mm to 175 mm. The wall thickness of the axially modified pipe may be between 8 mm and 15 mm.

[0047] Generally, an axially modified pipe 100 can be formed by welding a series of tubular sections together from one end to the other. A modified pipe having a section with a rough inner surface (roughed section) and another section with a smooth inner surface (smooth section) can be formed by welding correspondingly formed tubular sections together.

[0048] The axial reforming tube 100 may form part of the reforming system RS. As shown in Figure 4, in the reforming system RS, the reforming tube 100 is provided with a heater, and the catalyst bed CAT is filled into the reforming tube 100. Multiple axial reforming tubes 100 may be coupled parallel to each other to receive the reagent flow RF. The heater may be a furnace H through which the reforming tube 100 passes (or alternative heaters may be provided, such as ribbon heaters wrapped around each reforming tube). A rectifier FS may be provided upstream of the catalyst bed CAT to reduce turbulence in the reagent flow F to the catalyst. A control system CS is provided to monitor the gas flow rate and temperature of various parts of the reforming system, for example, before the reagent enters the catalyst and after the reagent exits the catalyst at one or more locations along the length range of the filled catalyst. The control system CS monitors each reforming tube 100, for example, but as an example, a monitor M is shown on only one reforming tube. Pump P is provided to deliver reagents to the catalyst. Pump P is provided, for example, downstream of the product flow after the gas has cooled following an endothermic reaction.

[0049] Figures 5A and 5B show exemplary experimental data in which the heat transfer coefficient and pressure drop were measured for 100 axially modified tubes (tubes 1-3 below) with different internal Ra roughness values. [Tube 1] Modified tube with an inner surface Ra roughness of 3.2 μm [Tube 2] Modified tube with an inner surface Ra roughness of 25 μm [Tube 3] Modified tube with an inner surface Ra roughness of 375 μm

[0050] In the test apparatus, air was drawn into the axially modified tube 100 via a rectifier FS and then pumped through a bed of catalyst (catalyst bed CAT) containing catalyst (spheres with a diameter of 16 mm and a porosity of 0.56) by a pump P. The outside of each axially modified tube 100 was heated by a ribbon heater wrapped around the tube. Each axially modified tube was tested twice, and corresponding data was collected as shown in the figure.

[0051] Figure 5A shows the heat transfer coefficient for each reformed tube (tube 1-3), and Figure 5B shows the pressure drop (pressure loss) within each reformed tube (tube 1-3). Tube 1 has a smooth inner surface and serves as a control tube for comparison. The heat transfer coefficients measured in tubes 2 and 3 were approximately 10% higher than those of tube 1.

[0052] In tube 1, the resistance to the gas flow F adjacent to the inner surface of the axially reformed pipe 100 is lowest. In tubes 2 and 3, the pressure drop is also greater than that of tube 1, which means that the resistance to the gas flow adjacent to the inner surface of the axially reformed pipe increases.

[0053] Table 1 below shows other exemplary experimental data regarding the measurement of heat transfer coefficient and pressure drop for multiple axially reformed tubes with different Rt roughness (and different Ra roughness) values. Multiple Rt roughness values ​​were used, ranging from smooth to 2500 μm (for Ra roughness, e.g., from smooth to approximately 625 μm). Catalyst beds consisting of spherical or cylindrical catalysts were also used. Figure 6 shows the heat transfer coefficients of the prototype axially reformed tubes in Table 1.

[0054] [Table 1]

[0055] Up to an Rt roughness of 1500 μm or 2000 μm on the inner surface of the axially modified tube (e.g., Ra roughness of approximately 375 μm or 500 μm), the heat transfer coefficient increases. The overall pressure drop hardly increases. Beyond an Rt roughness of 2000 μm, the fabrication of deeper grooves becomes complicated, and as a result, the heat transfer coefficient does not substantially improve.

[0056] Figure 7A shows a simulation plot of the gas temperature along the center plane of an axially reformed pipe with a smooth inner surface (e.g., Rt roughness of 25 μm or less), and Figure 7B shows a simulation plot of the gas temperature along the center plane of an axially reformed pipe with an Rt roughness of 2000 μm (e.g., Ra roughness of 500 μm). In both cases, the same cylindrical catalyst bed is used. Figure 7B shows how the heat transfer coefficient through the pipe wall is improved by providing a 2000 μm Rt roughness on a portion of the inner surface of the axially reformed pipe.

[0057] The figures provided in this application are schematic and not to scale.

[0058] Throughout this description and claims, the terms “equipped,” “having,” and “including,” and related terms, mean “not necessarily to include,” and are not intended to exclude other parts, appendices, elements, integers, or steps. Throughout this description and claims, singular nouns encompass plural nouns unless otherwise specified in the context. In particular, where the indefinite article is used, the specification should be understood to consider both singular and plural nouns unless otherwise specified in the context.

[0059] Features, integers, properties, compounds, chemical parts, or groups described in connection with specific aspects, embodiments, or examples of the present invention should be understood to be applicable to any other aspects, embodiments, or examples described herein, insofar as they do not conflict therewith. All features disclosed herein (including the appended claims, abstract, and drawings), and / or all steps of any method or process so thus disclosed, can be combined in any combination, except for combinations in which at least some of such features and / or steps are mutually exclusive. The present invention is not limited to the details of the embodiments described above. The present invention extends to any novel features or any novel combination of features disclosed herein (including the appended claims, abstract, and drawings), or any novel steps or any novel combination of steps of any method or process.

[0060] Attention has been paid to all papers and documents filed concurrently with or prior to this specification in connection with this application and made available to the public together with this specification, the contents of all such papers and documents are incorporated herein by reference.

Claims

1. At least a portion of the inner surface of the axially modified tube has a roughened surface portion with an arithmetic mean roughness of 12.5 μm or more and 500 μm or less. The axially modified pipe extends along its axial length, and the roughened portion has a circumferential groove pattern. The deviation of the circumferential groove from the circumferential direction on the inner surface of the axially modified tube is 10 degrees or less. The circumferential grooves are separated from each other by top surfaces, and sharp edges are formed between the top surfaces and the sides of the circumferential grooves, with the sharp edges having an average radius of curvature of 20 μm or less. Axial-modified pipe.

2. At least a portion of the axially modified tube is a roughened surface having an inner surface with an arithmetic mean roughness of at least 25 μm. The axially modified pipe according to claim 1.

3. The deviation of the circumferential groove from the circumferential direction on the inner surface of the axially modified pipe is 5 degrees or less. The axially modified pipe according to claim 1.

4. The pattern of the circumferential groove is formed as one or more helical grooves. The axially modified pipe according to claim 1.

5. The side surface of the circumferential groove is inclined by a lateral angle between 0 and 50 degrees with respect to the plane perpendicular to the axial length. The axially modified pipe according to claim 1.

6. The side surface of the circumferential groove is inclined by a lateral angle between 0 and 30 degrees with respect to the plane perpendicular to the axial length. The axially modified pipe according to claim 5.

7. The aforementioned side angle is at least 10 degrees. The axially modified pipe according to claim 5.

8. The aforementioned side angle is 25 degrees or less. The axially modified pipe according to claim 5.

9. The axial length of the bottom of the circumferential groove is 50% to 200% of the depth of the circumferential groove. The axially modified pipe according to claim 1.

10. The circumferential grooves are separated from each other by their top surfaces, and the axial length of the top surfaces is 50% to 100% of the depth of the circumferential grooves. The axially modified pipe according to claim 1.

11. The roughened portion extends along the entire length of the axially modified pipe. The axially modified pipe according to claim 1.

12. The axially modified tube has an arithmetic mean roughness of 3.2 μm or less and includes a smooth surface portion bonded to the rough surface portion. The axially modified pipe according to claim 1.

13. The roughened portion is bonded between the two smoothed portions. The axially modified pipe according to claim 12.

14. The axially modified pipe has a length of at least 700 mm. The axially modified pipe according to claim 1.

15. The inner diameter of the axially modified pipe is 350 mm or less. The axially modified pipe according to claim 1.

16. The axially modified pipe has a length of at least 2 meters, and the inner diameter of the axially modified pipe is between 95 mm and 280 mm. The axially modified pipe according to claim 1.

17. The axially modified pipe has a length of at least 2 meters, and its inner diameter is between 95 mm and 250 mm. The axially modified pipe according to claim 1.

18. A reforming system comprising an axial reforming pipe according to any one of claims 1 to 17.

19. A catalyst bed filled in at least a portion of the axial reforming tube, A heater for heating at least a portion of the axially modified tube, A pump that sends gas through the catalyst bed, The system further comprises a control system for monitoring and controlling the operation of the modification system. The modification system according to claim 18.

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