Box-type combined reformer

Abstract

One embodiment of the present invention provides a box-type composite reformer comprising: a box-type main body; a plurality of first catalyst tubes installed in the main body and reacting at a first temperature; a plurality of second catalyst tubes installed in the main body and reacting at a second temperature higher than the first temperature; and a combustion unit for supplying heat to the plurality of first catalyst tubes and the plurality of second catalyst tubes, wherein the combustion unit is disposed at the center of the main body, the plurality of first catalyst tubes are disposed facing each other on both sides of the combustion unit, and the plurality of second catalyst tubes are disposed facing each other on both sides of the combustion unit, inside the plurality of first catalyst tubes.

Description

Technology Field

[0001] The present invention relates to a box-type composite reformer, and more specifically, to a box-type composite reformer in which the reformer is in the shape of a box and catalyst tubes are symmetrically arranged to face each other with respect to a burner, thereby enabling an increase in reforming capacity without a decrease in reforming efficiency, and in which the reforming capacity can be easily increased by increasing the number of catalyst tubes in the width direction of the reformer or by connecting multiple reformers in a modular form. Background Technology

[0002] Conventional steam methane reformers (SMRs) are facilities for reforming natural gas in which methane (CH4) is the main component. As disclosed in Korean Patent Publication No. 2019-0112290, when reforming gas containing hydrocarbons with a high number of carbon atoms (CxHy), a separate facility called a pre-reformer must be added to convert it into methane before reforming, which has the problem of complex structure and process.

[0003] To address this, Korean Patent Publication No. 2023-0049360 discloses a composite reformer. The composite reformer includes two or more catalyst tubes (200, 400) that react at different temperatures, thereby enabling the reforming of a hydrocarbon (CxHy) having two or more carbon atoms into methane (CH4) and simultaneously reforming the methane (CH4) into a synthesis gas containing hydrogen (H2) and carbon monoxide (CO).

[0004] In a conventional composite reformer, the first catalyst tubes (200) and the second catalyst tubes (400) are arranged in an annular shape around the combustion section (500) located in the center of the reformer. In this case, if the number of catalyst tubes is increased to increase the capacity of the composite reformer, the distance between the first catalyst tubes (200) and the second catalyst tubes (400) becomes larger. As a result, the flow path space through which the combustion gas passes outside each catalyst tube becomes larger, leading to a decrease in the amount of heat absorbed by the tubes due to the decrease in the flow velocity of the combustion gas, and ultimately, a problem arises in that the reforming efficiency decreases.

[0005] If the thickness of the first wall (120) between the first catalyst tube (200) and the second catalyst tube (400) is increased so that the area of ​​the combustion gas flow path does not increase, or if refractory materials such as refractory bricks are placed at the bottom of the reformer, there is a problem that the weight and cost of the reformer increase. Prior art literature

[0006] Korean Patent Publication No. 2019-0112290 (Published Oct. 04, 2019) Korean Patent Publication No. 2023-0049360 (Published Apr. 13, 2023) The problem to be solved

[0007] The purpose of the present invention is to provide a box-type composite reformer that enables an increase in reforming capacity without a decrease in reforming efficiency, as the reformer is in the form of a box and the catalyst tubes are symmetrically arranged to face each other with the burner as the center, and facilitates an increase in reforming capacity by increasing the number of catalyst tubes in the width direction of the reformer or by connecting multiple reformers in a modular form.

[0008] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0009] An embodiment of the present invention for solving the above problem provides a box-type composite reformer comprising: a box-type main body; a plurality of first catalyst tubes installed in the main body and reacting at a first temperature; a plurality of second catalyst tubes installed in the main body and reacting at a second temperature higher than the first temperature; and a combustion unit for supplying heat to the plurality of first catalyst tubes and the plurality of second catalyst tubes, wherein the combustion unit is disposed at the center of the main body, the plurality of first catalyst tubes are disposed facing each other on both sides of the combustion unit, and the plurality of second catalyst tubes are disposed facing each other on both sides of the combustion unit, inside the plurality of first catalyst tubes.

[0010] According to an embodiment, the plurality of first catalyst tubes and the plurality of second catalyst tubes may be symmetrically arranged on both sides of the combustion section.

[0011] According to an embodiment, the plurality of first catalyst tubes disposed on the same side of the combustion section may be arranged parallel to each other along the width direction of the main body, and the plurality of second catalyst tubes disposed on the same side of the combustion section may be arranged parallel to each other along the width direction of the main body.

[0012] According to an embodiment, each of the first catalyst tubes is formed in a U-shape, and the plurality of first catalyst tubes can be arranged side by side so that the U-shapes face each other.

[0013] According to an embodiment, it may further include a plurality of inlet pipes connected to each of the plurality of first catalyst tubes and extending to the outside of the main body; and an inlet header connected to the plurality of inlet pipes.

[0014] According to an embodiment, it may further include a plurality of outlet pipes connected to each of the plurality of second catalyst tubes and extending to the outside of the main body; and an outlet header connected to the plurality of outlet pipes.

[0015] According to an embodiment, a flow control unit may be installed between each of the inlet pipes and the inlet headers to control the flow rate of hydrocarbon gas flowing into each of the first catalyst tubes.

[0016] According to an embodiment, a plurality of combustion gas discharge pipes each connected to the main body on both sides of the combustion section may be further included so that combustion gas generated in the combustion section is discharged.

[0017] According to an embodiment, the combustion unit includes a plurality of burners, and the plurality of burners may be spaced apart along the width direction of the main body.

[0018] According to an embodiment, the plurality of burners can burn the same fuel.

[0019] According to an embodiment, the plurality of burners can burn different fuels.

[0020] According to an embodiment, some of the plurality of burners may receive and burn a portion of the hydrocarbon gas supplied to the first catalyst tube, and the remaining portion may receive and burn tail gas from which hydrogen has been separated from the synthesis gas discharged from the second catalyst tube.

[0021] According to an embodiment, the combustion unit includes a plurality of burners, some of which may be disposed on the end surface of the main body and the remaining parts disposed on the side of the main body.

[0022] According to an embodiment, the combustion unit includes a burner installed outside the main body, and combustion may occur inside the main body.

[0023] According to an embodiment, the combustion unit may include a burner installed outside the main body, a combustion furnace connected to the burner and installed outside the main body, and a connecting duct connecting the combustion furnace and the main body.

[0024] According to an embodiment, the connecting duct may become wider in the width direction of the main body as it extends from the combustion furnace to the main body.

[0025] Another embodiment of the present invention for solving the above problem provides a box-type composite reformer module system comprising a plurality of box-type composite reformers, wherein each of the box-type composite reformers comprises: a box-type body; a plurality of first catalyst tubes installed in the body and reacting at a first temperature; a plurality of second catalyst tubes installed in the body and reacting at a second temperature higher than the first temperature; a combustion unit for supplying heat to the plurality of first catalyst tubes and the plurality of second catalyst tubes; and a plurality of inlet pipes connected to each of the plurality of first catalyst tubes and extending to the outside of the body; wherein an inlet header is provided that extends along the plurality of box-type composite reformers and is connected to all of the plurality of inlet pipes of the plurality of box-type composite reformers.

[0026] According to an embodiment, each of the above-mentioned box-type composite reformers further comprises a plurality of outlet pipes connected to each of the plurality of second catalyst tubes and extending to the outside of the main body; and may be provided with an outlet header extending along the plurality of box-type composite reformers and connected to all of the plurality of outlet pipes of the plurality of box-type composite reformers.

[0027] According to an embodiment, the combustion unit is positioned at the center of the main body, the plurality of first catalyst tubes are positioned facing each other on both sides of the combustion unit, and the plurality of second catalyst tubes may be positioned facing each other on both sides of the combustion unit, further inside than the plurality of first catalyst tubes.

[0028] According to an embodiment, the plurality of first catalyst tubes disposed on the same side of the combustion section are arranged parallel to each other along the width direction of the main body through which the inlet header extends, and the plurality of second catalyst tubes disposed on the same side of the combustion section may be arranged parallel to each other along the width direction of the main body. Effects of the invention

[0029] According to the present invention, since the reformer is in the form of a box and the catalyst tubes are symmetrically arranged to face each other with the burner as the center, it is possible to increase the reforming capacity without reducing the reforming efficiency. Specifically, even if the number of catalyst tubes is increased in the width direction of the reformer, the distance between the first catalyst tube and the second catalyst tube does not increase, so the reforming capacity is increased without a decrease in reforming efficiency. In addition, since multiple box-type composite reformers can be connected in a modular form, it is easy to increase the reforming capacity. Furthermore, since the external shape of the reformer is formed in a box shape, the manufacturing cost can be reduced.

[0030] In addition, since a flow control unit is installed in each of the multiple inlet pipes, if a difference in the amount of heat absorbed by each first catalyst tube occurs due to factors such as combustion gas imbalance, the flow rate of hydrocarbon gas flowing into each first catalyst tube can be controlled. That is, the reaction temperature conditions of the tubes can be adjusted by reducing the flow rate of hydrocarbon gas flowing into the tube with a lower amount of heat absorbed.

[0031] In addition, since the combustion section includes a plurality of burners spaced apart along the width direction of the main body or a plurality of burners arranged on the end surface and side of the main body, it is possible to prevent the occurrence of a dead zone with minimal flame influence inside the main body, thereby preventing a reduction in the heat absorption capacity of the tube due to the occurrence of a dead zone.

[0032] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims. Brief explanation of the drawing

[0033] FIG. 1 is a perspective view illustrating a box-type composite reformer according to a first embodiment of the present invention. FIG. 2 is a perspective view in which the inlet header, outlet header, and part of the main body are omitted from FIG. 1. Figure 3 is a horizontal cross-sectional view of Figure 2. FIG. 4 is a vertical cross-sectional view of the box-type composite reformer of FIG. 1 with the inlet header and outlet header omitted. Figure 5 is a vertical cross-sectional view of Figure 1. FIGS. 6 and 7 are vertical cross-sectional views illustrating other embodiments of the combustion section of FIG. 5. FIG. 8 is a perspective view illustrating a box-type composite reformer according to a second embodiment of the present invention. FIG. 9 is a perspective view illustrating a box-type composite reformer according to a third embodiment of the present invention. Figure 10 is a vertical cross-sectional view of Figure 9. Figure 11 is a partial vertical cross-sectional view of Figure 9. FIG. 12 is an enlarged cross-sectional view showing the connection portion between the inlet header and a plurality of inlet pipes in a box-type composite reformer according to the fourth embodiment of the present invention. FIG. 13 is a plan view showing the orifices of FIG. 12 separated. FIG. 14 is a perspective view illustrating the box-type composite reformer module system of the present invention. Specific details for implementing the invention

[0034] Hereinafter, a preferred embodiment of the box-type composite reformer of the present invention will be described with reference to the attached drawings.

[0035] Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intention or practice of the user or operator; additionally, the following embodiments are not intended to limit the scope of the present invention but are merely exemplary details of the components presented in the claims of the present invention.

[0036] To clearly explain the present invention, parts unrelated to the description have been omitted, and the same reference numerals are used for identical or similar components throughout the specification. Throughout the specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may additionally include other components.

[0037] In addition, components referred to as '~parts' throughout the specification may consist of two or more components combined into a single component, or a single component may be divided into two or more components based on more detailed functions. Furthermore, each component described below may additionally perform some or all of the functions performed by other components in addition to its primary function, and it goes without saying that some of the primary functions performed by each component may be exclusively performed by other components.

[0039] First, let us look at a box-type composite reformer (1) according to the first embodiment of the present invention with reference to FIGS. 1 to 5.

[0040] A box-type composite reformer (1) according to the first embodiment of the present invention may include a box-type main body (100), a first catalyst tube (200), a connecting tube (300), a second catalyst tube (400), a combustion section (500), an inlet pipe (250), an inlet header (600), an outlet pipe (450), an outlet header (700), and a combustion gas discharge pipe (800).

[0041] The box-shaped main body (100) forms the outer shape of the reformer and is formed in the shape of a box having an internal space.

[0042] Two or more catalyst tubes that react at different temperatures are installed in the main body (100). Specifically, a plurality of first catalyst tubes (200) that react at a first temperature (T1) and a plurality of second catalyst tubes (400) that react at a second temperature (T2) higher than the first temperature (T1) are provided. The first temperature (T1) and the second temperature (T2) can be set differently depending on the reaction that takes place in the first catalyst tubes (200) and the second catalyst tubes (400).

[0043] In the first catalyst tube (200), hydrocarbon gas containing hydrocarbons and steam are supplied. In this embodiment, the explanation is based on the assumption that biogas containing methane and carbon dioxide is supplied as the hydrocarbon gas. When biogas and steam are supplied to the first catalyst tube (200) in this manner, in the first catalyst tube (200), methane reacts with steam through reaction equation (1) to be reformed into syngas containing hydrogen and carbon monoxide (wet reforming), and in the second catalyst tube (400), methane reacts with carbon dioxide through reaction equation (2) to be reformed into syngas containing hydrogen and carbon monoxide (dry reforming).

[0044] Reaction Equation (1) ------- CH4 + H2O → CO + 3H2

[0045] Reaction Equation (2) ------- CH4 + CO2 → 2CO + 2H2

[0046] Here, the first temperature (T1), which is the reaction temperature of the first catalyst tube (200), may be approximately 450°C to 650°C, and a catalyst for wet reforming methane may be applied to the first catalyst tube (200). For example, a nickel-based catalyst using MgO or Al2O3 or a combination thereof as a support may be applied to the first catalyst tube (200). The second temperature (T2), which is the reaction temperature of the second catalyst tube (400), may be approximately 650°C to 850°C, and a catalyst for dry reforming methane may be applied to the second catalyst tube (400). For example, a nickel-based catalyst may also be applied to the second catalyst tube (400).

[0047] Although it is described that the wet reforming reaction of methane takes place in the first catalyst tube (200), it is obvious that since the wet reforming reaction of methane can take place over a wide temperature range, it can also take place in part in the second catalyst tube (400).

[0048] The first catalyst tube (200) and the second catalyst tube (400) are connected through a connecting tube (300), so that biogas and steam supplied to the first catalyst tube (200) can flow sequentially from the first catalyst tube (200) to the second catalyst tube (400) through the connecting tube (300). Accordingly, biogas and steam can flow sequentially through the first catalyst tube (200) and the second catalyst tube (400) and be reformed into synthesis gas through wet reforming and dry reforming reactions. That is, in the first catalyst tube (200), methane can react with steam to be converted into synthesis gas, and methane that did not react in the first catalyst tube (200) can react with carbon dioxide in the second catalyst tube (400) to be converted into synthesis gas. In this case, since it is not necessary to separately remove carbon dioxide from the biogas and supply it to the reformer, a device for removing carbon dioxide is not required.

[0049] A combustion unit (500) for supplying heat to a plurality of first catalyst tubes (200) and a plurality of second catalyst tubes (400) is installed in the main body (100). The combustion unit (500) is positioned at the center along the longitudinal direction (l) of the main body (100). As a result, combustion gas generated in the combustion unit (500) is supplied to the center of the main body (100).

[0050] At this time, a plurality of first catalyst tubes (200) are arranged to face each other on both sides of the combustion section (500) along the longitudinal direction (l), and a plurality of second catalyst tubes (400) are also arranged to face each other on both sides of the combustion section (500) along the longitudinal direction (l) from the inner side of the plurality of first catalyst tubes (200). In particular, a plurality of first catalyst tubes (200) arranged on the same side of the combustion section (500) are arranged parallel to each other along the width direction (w) of the main body (100), and a plurality of second catalyst tubes (400) arranged on the same side of the combustion section (500) are also arranged parallel to each other along the width direction (w) of the main body (100). Furthermore, it is preferable that a plurality of first catalyst tubes (200) and a plurality of second catalyst tubes (400) are arranged symmetrically on both sides of the combustion section (500).

[0051] Specifically, in this embodiment, a total of 10 first catalyst tubes (200) are provided, and 5 of the first catalyst tubes (200) are symmetrically arranged to face each other on both sides of the combustion section (500). In addition, the 5 first catalyst tubes (200) placed on the same side of the combustion section (500) are arranged in parallel and spaced apart at regular intervals along the width direction (w) of the main body (100). Likewise, a total of 10 second catalyst tubes (400) are provided, and 5 of the second catalyst tubes (400) are symmetrically arranged to face each other on both sides of the combustion section (500). In addition, the 5 second catalyst tubes (400) placed on the same side of the combustion section (500) are arranged in parallel and spaced apart at regular intervals along the width direction (w) of the main body (100). At this time, in order to minimize the width of the main body (100), it is preferable that the first catalyst tube (200) and the second catalyst tube (400) be arranged parallel to each other along the longitudinal direction (l) of the main body (100).

[0052] The connecting tubes (300) are also made up of a total of 10, each connecting one first catalyst tube (200) and one second catalyst tube (400). The number of catalyst tubes and connecting tubes can be varied depending on the size of the reformer, etc.

[0053] In this way, since the reformer is in the shape of a box and the catalyst tubes (200, 400) are symmetrically arranged to face each other with respect to the combustion section (500), it is possible to increase the reforming capacity without reducing the reforming efficiency. Specifically, even if the number of catalyst tubes (200, 400) is increased in the width direction (w) of the reformer, the distance between the first catalyst tube (200) and the second catalyst tube (400) does not increase, so the reforming capacity is increased without reducing the reforming efficiency. Furthermore, since the external shape of the reformer is formed in the shape of a box, the manufacturing cost can be reduced.

[0054] Since the plurality of second catalyst tubes (400) are positioned further inside than the plurality of first catalyst tubes (200), the combustion gas supplied from the combustion unit (500) supplies heat to the plurality of second catalyst tubes (400) and then supplies heat to the plurality of first catalyst tubes (200), and the second catalyst tubes (400) can react at a higher temperature than the first catalyst tubes (200).

[0055] A first wall (120) and a second wall (140) may be provided inside the main body (100) to guide the flow of combustion gas supplied from the combustion section (500) in order to effectively supply heat to a plurality of first catalyst tubes (200) and a plurality of second catalyst tubes (400). The first wall (120) is provided between a plurality of first catalyst tubes (200) and a plurality of second catalyst tubes (400) and extends vertically upward from the lower side of the main body (100) in the drawing. Additionally, the second wall (140) is provided radially inside the plurality of second catalyst tubes (400) and extends vertically downward from the upper side of the main body (100) in the drawing. The widths of both the first wall (120) and the second wall (140) correspond to the width of the main body (100). Accordingly, the combustion gas supplied from the combustion section (500) flows in a zigzag pattern along the longitudinal direction of the first catalyst tube (200) and the second catalyst tube (400) to sufficiently supply heat to the first catalyst tube (200) and the second catalyst tube (400), and a temperature gradient according to the reaction temperature can be applied. To improve heat transfer efficiency, fins may be placed on the first catalyst tube (200) and / or the second catalyst tube (400).

[0056] In some cases, a recirculation wall (160) may be further provided that has a width corresponding to the width of the main body (100) and crosses a plurality of second catalyst tubes (400). Since the recirculation wall (160) is provided at a distance from both the upper and lower surfaces of the main body (100), as shown by the dotted arrow in FIG. 4, combustion gas can be recirculated by flowing outward through the space below the recirculation wall (160) and then flowing back inward through the space above the recirculation wall (160). In addition, the remaining combustion gas will continue to flow outward through the space above the first wall (120), that is, toward a plurality of first catalyst tubes (200).

[0057] In this manner, after supplying heat to a plurality of first catalyst tubes (200) and a plurality of second catalyst tubes (400), the combustion gas can be discharged to the outside through a plurality of combustion gas discharge pipes (800) each connected to the main body (100) on both sides of the combustion section (500). As a result, the combustion gas flowing to each side of the combustion section (500) can be easily discharged through each combustion gas discharge pipe (800). Although the plurality of combustion gas discharge pipes (800) are shown as converging in the drawing, they are not limited thereto.

[0058] A plurality of first catalyst tubes (200) and a plurality of second catalyst tubes (400) are extended vertically along the height direction (h) of the main body (100). In this embodiment, the first catalyst tube (200) is formed in a U-shape, and the second catalyst tube (400) is formed as a bayonet tube. However, this is not limited thereto, and to reduce the length of the main body (100), both the first catalyst tube (200) and the second catalyst tube (400) may be bayonet tubes.

[0059] In particular, it is preferable that a plurality of first catalyst tubes (200) be arranged side by side so that their U-shapes face each other, and as the first catalyst tubes (200) are formed in a U-shape, the reaction time of the catalyst can be extended.

[0060] Each of the second catalyst tubes (400) includes an outer tube (420) and an inner tube (440) disposed inside the outer tube (420). The inner tube (440) extends from the interior of the outer tube (420) but does not come into contact with the lower end of the outer tube (420), forming a certain space between them. As a result, the outer tube (420) and the inner tube (440) can communicate with each other, and gas introduced between the outer tube (420) and the inner tube (440) through the connecting tube (300) can flow into the interior of the inner tube (440). In this embodiment, the connecting tube (300) is connected to the outer tube (420), but it may also be connected to the inner tube (440).

[0061] In order to supply hydrocarbon gas and steam to a plurality of first catalyst tubes (200), an inlet pipe (250) extending to the outside of the main body (100) is connected to each of the plurality of first catalyst tubes (200). In this embodiment, the inlet pipe (250) is formed integrally with the first catalyst tube (200). An inlet header (600) is connected to the plurality of inlet pipes (250) outside the main body (100). To this end, the inlet header (600) extends along the width direction (w) of the main body (100) where the plurality of first catalyst tubes (200) are arranged side by side. As a result, the hydrocarbon gas and steam supplied to the inlet header (600) can be divided and supplied to each of the first catalyst tubes (200) through the inlet pipe (250). At this time, each inlet pipe (250) has a first flange (252), and the inlet header (600) has a second flange (602) corresponding to the first flange (252), and the inlet pipe (250) and the inlet header (600) can be connected by joining the first flange (252) and the second flange (602) to each other.

[0062] In order to discharge synthesis gas from a plurality of second catalyst tubes (400), an outlet pipe (450) extending to the outside of the main body (100) is connected to each of the plurality of second catalyst tubes (400). In this embodiment, the outlet pipe (450) is formed integrally with the second catalyst tube (400). An outlet header (700) is connected to the plurality of outlet pipes (450) outside the main body (100). To this end, the outlet header (700) extends along the width direction (w) of the main body (100) where the plurality of second catalyst tubes (400) are arranged side by side. As a result, the synthesis gas discharged from each of the second catalyst tubes (400) can be collected and discharged through the outlet pipe (450) to the outlet header (700). At this time, each outflow pipe (450) has a third flange (452), and the outflow header (700) has a fourth flange (702) corresponding to the third flange (452), and the outflow pipe (450) and the outflow header (700) can be connected by joining the third flange (452) and the fourth flange (702) to each other.

[0063] In the present invention, since a plurality of catalyst tubes (200, 400) are arranged in parallel along the width direction (w) of the main body (100), a dead zone with little influence from the flame may occur inside the main body (100) (particularly at the upper end of the width direction of the main body). Therefore, to prevent this, the combustion unit (500) may include a plurality of burners (520) spaced apart along the width direction (w) of the main body (100). As a result, as shown in FIG. 5, combustion gas can be supplied widely along the width direction (w) of the main body (100), thereby preventing a reduction in the heat absorption amount of the tubes due to the occurrence of a dead zone.

[0064] In FIG. 5, the burner (520) is installed outside the main body (100), and combustion takes place inside the main body (100).

[0065] At this time, the multiple burners (520) may burn the same fuel, but as in the present embodiment, they may burn different fuels. Specifically, some of the multiple burners (520) may receive and burn a portion of the hydrocarbon gas supplied to the first catalyst tube (200), and the remaining portion may receive and burn tail gas from which hydrogen has been separated from the synthesis gas discharged from the second catalyst tube (400).

[0066] In addition, in FIG. 5, multiple burners (520) are all formed with the same size as main burners (520a).

[0067] However, depending on the case, as shown in FIG. 6, only some of the multiple burners (520) may be composed of main burners (520a), and the rest may be composed of auxiliary burners (520b) that are smaller in size than the main burners (520a). In FIG. 6, the burner located at the center in the width direction (w) of the main body (100) is composed of main burners (520a), and the burners on both sides are composed of auxiliary burners (520b). For example, the main burner (520a) may burn hydrocarbon gas, and the auxiliary burner (520b) may burn tail gas.

[0068] In addition, as shown in FIG. 7, a plurality of main burners (520a) and a plurality of auxiliary burners (520b) arranged on each side of each main burner (520a) may be provided.

[0070] Although the above description is based on the assumption that biogas is supplied as the hydrocarbon gas, depending on the embodiment, a hydrocarbon gas containing a high hydrocarbon with two or more carbon atoms may be supplied as the hydrocarbon gas. In this way, when a hydrocarbon gas containing a high hydrocarbon and steam are supplied to the first catalyst tube (200), the reforming reaction taking place in the first catalyst tube (200) and the second catalyst tube (400) is as follows.

[0071] In the first catalyst tube (200), a hydrocarbon with two or more carbon atoms reacts with steam to be reformed into methane through reaction equations (3) and (4), and in the second catalyst tube (400), methane reacts with steam through reaction equation (5) to be reformed into a synthesis gas containing hydrogen and carbon monoxide.

[0072] Reaction Equation (3) ------- CnHm + nH2O → nCO + (n+m / 2)H2

[0073] Reaction Equation (4) ------- CO + 3H2 → CH4 + H2O

[0074] Reaction Equation (5) ------- CH4 + H2O → CO + 3H2

[0075] Here, the first temperature (T1), which is the reaction temperature of the first catalyst tube (200), may be approximately 350°C to 550°C, and a catalyst for reforming high hydrocarbons may be applied to the first catalyst tube (200). As a result, in the first catalyst tube (200), high hydrocarbons having two or more carbon atoms, such as ethane, propane, and butane, may be converted into methane, carbon monoxide, and hydrogen. The second temperature (T2), which is the reaction temperature of the second catalyst tube (400), may be approximately 700°C to 900°C, and a catalyst for reforming methane may be applied to the second catalyst tube (400).

[0076] Although it is described that the wet reforming reaction of methane takes place in the second catalyst tube (400), it is obvious that since the wet reforming reaction of methane can occur over a wide temperature range, it can also take place in part in the first catalyst tube (200).

[0077] In this way, even if the hydrocarbon gas supplied to the first catalyst tube (200) contains a large amount of high hydrocarbons, it can be reformed into synthesis gas through a steam reforming reaction while flowing sequentially through the first catalyst tube (200) and the second catalyst tube (400). That is, high hydrocarbons can be converted into methane in the first catalyst tube (200), and the methane converted in the first catalyst tube (200) can be introduced into the second catalyst tube (400) and converted into synthesis gas. In particular, the hydrocarbon gas supplied to the first catalyst tube (200) may be a pyrolysis gas generated by the pyrolysis of waste. For example, it may be a pyrolysis gas generated by the pyrolysis of waste plastic, and it contains a large amount of high hydrocarbons having two or more carbon atoms.

[0079] Next, with reference to FIG. 8, we will examine a box-type composite reformer according to a second embodiment of the present invention. Here, we will focus on describing only the combustion section (1500), which is different from the composite reformer shown in FIG. 1.

[0080] The combustion unit (1500) includes a plurality of burners (1520), some of the plurality of burners (1520) are positioned on the end surface of the main body (100), and the remaining portions are positioned on the side surface of the main body (100). In this embodiment, one burner (1520) is positioned at the center of the upper surface of the main body (100), and three burners (1520) are positioned in the height direction on each side surface of the main body (100). As the burners (1520) are positioned on both the end surface and the side surface of the main body (100) in this manner, a dead zone with little influence from the flame is prevented from forming inside the main body (100) (especially at the upper end in the width direction of the main body), thereby preventing a reduction in the heat absorption amount of the tube.

[0082] Next, with reference to FIGS. 9 to 11, we will examine a box-type composite reformer according to a third embodiment of the present invention. Here, we will focus on describing only the combustion section (2500), which is different from the composite reformer shown in FIG. 1.

[0083] The combustion unit (2500) includes a burner (2520) installed on the outside of the main body (100), a combustion furnace (2540) connected to the burner (2520) and installed on the outside of the main body (100), and a connecting duct (2560) connecting the combustion furnace (2540) and the main body (100). As such, since a separate combustion furnace (2540) is provided on the outside of the main body (100), combustion does not occur inside the main body (100), but rather combustion occurs in the combustion furnace (2540), after which the combustion gas is supplied into the inside of the main body (100) through the connecting duct (2560).

[0084] At this time, it is preferable that the connecting duct (2560) widens in the width direction (w) of the main body (100) as it extends from the combustion chamber (2540) to the main body (100). Accordingly, even if only one burner (2520) and combustion chamber (2540) are formed, the combustion gas can be supplied widely in the width direction (w) of the main body (100), thereby preventing the formation of a dead zone with minimal flame influence inside the main body (100) (especially at the end of the main body in the width direction), and thus preventing a reduction in the heat absorption amount of the tube.

[0085] However, it is not limited to this, and multiple burners (2520) and multiple combustion chambers (2540) may be spaced apart along the width direction (w) of the main body (100).

[0087] Next, with reference to FIGS. 12 and 13, we will examine a box-type composite reformer according to the fourth embodiment of the present invention. Since there is a difference in that a flow rate control unit (900) is additionally installed in the composite reformer shown in FIG. 1, the flow rate control unit (900) will be explained in detail.

[0088] In this embodiment, a flow control unit (900) for controlling the flow rate of hydrocarbon gas flowing into each first catalyst tube (200) is installed between each inlet pipe (250) and the inlet header (600). Specifically, the flow control unit (900) is installed between the first flange (252) of the inlet pipe (250) and the second flange (602) of the inlet header (600). Any configuration for controlling the flow rate of gas, such as an orifice or a valve, can be applied to the flow control unit (900).

[0089] Accordingly, if a difference in the amount of heat absorbed by each first catalyst tube occurs due to factors such as combustion gas imbalance, the flow rate of hydrocarbon gas flowing into each first catalyst tube (200) can be controlled by the flow rate control unit (900). That is, the reaction temperature conditions of the tube can be adjusted by reducing the flow rate of hydrocarbon gas flowing into the first catalyst tube with a low amount of heat absorbed.

[0090] If, in a plurality of first catalyst tubes (200), the amount of heat absorbed is greater the closer it is to the center in the width direction (w) of the main body (100), then as shown in FIG. 13, the nozzle size of the orifice located at the center will be the largest, and the nozzle size of the orifice will become smaller as it moves away from it. As a result, the greater the amount of heat absorbed by the first catalyst tubes (200), the more hydrocarbon gas can be introduced.

[0092] Finally, with reference to FIG. 14, we will examine the box-type composite reformer module system (10) of the present invention. The box-type composite reformer module system (10) is configured by connecting a plurality of box-type composite reformers (1), and each box-type composite reformer (1) connected in FIG. 14 has the same structure as the box-type composite reformer (1) described in FIG. 1.

[0093] As shown in FIG. 14, since a plurality of box-type composite reformers (1) can be connected side by side along the width direction (w), space utilization can be maximized when connecting multiple reformers to increase reforming capacity.

[0094] At this time, instead of multiple inlet headers being provided separately for each box-type composite reformer, a single inlet header (600) may be extended along multiple box-type composite reformers (1) and connected to all of the multiple inlet pipes (250) of the multiple box-type composite reformers (1). Accordingly, hydrocarbon gas and steam can be supplied to all first catalyst tubes (200) even if they are supplied only to one inlet header (600) without the need to supply hydrocarbon gas and steam to each of the multiple inlet headers. As illustrated, a single inlet header (600) formed integrally may be extended along multiple box-type composite reformers (1), but the inlet headers provided for each box-type composite reformer (1) may also be connected to each other to form a single inlet header (600).

[0095] Likewise, instead of having multiple outlet headers provided separately for each box-type composite reformer, a single outlet header (700) can be extended along multiple box-type composite reformers (1) and connected to multiple outlet pipes (450) of multiple box-type composite reformers (1). Accordingly, the synthesis gas discharged from all second catalyst tubes (400) can be collected and discharged through a single outlet header (700).

[0096] In this way, multiple box-type composite reformers (1) can be connected in a modular form, making it easy to increase the reforming capacity without increasing the complexity of the structure.

[0097] The present invention is not limited to the specific embodiments and descriptions described above, and various modifications can be made by anyone with ordinary knowledge in the technical field to which the present invention pertains without departing from the essence of the invention as claimed in the claims, and such modifications fall within the scope of protection of the present invention. Explanation of the symbols

[0098] 1: Box-type combined reformer 10: Box-type combined reformer module system 100: Box-type main body 120: The first wall 140: Second Wall 160: Recirculation wall 200: First catalyst tube 250: Inlet pipe 252: 1st flange 300: Connecting tube 400: Second catalyst tube 420: Outer Tube 440: Inner tube 450: Outflow pipe 452: 3rd flange 500, 1500, 2500: Combustion section 520, 1520, 2520: Burner 520a: Main burner 520b: Auxiliary burner 600: Inflow header 602: Second flange 700: Leak Header 702: 4th flange 800: Combustion gas exhaust pipe 900: Flow control unit 2540: Combustion furnace 2560: Connecting duct

Claims

Claim 1 A box-type composite reformer comprising: a box-type main body; a plurality of first catalyst tubes installed in the main body and reacting at a first temperature; a plurality of second catalyst tubes installed in the main body and reacting at a second temperature higher than the first temperature; and a combustion unit for supplying heat to the plurality of first catalyst tubes and the plurality of second catalyst tubes; wherein the combustion unit is positioned at the center of the main body, the plurality of first catalyst tubes are positioned facing each other on both sides of the combustion unit, the plurality of second catalyst tubes are positioned facing each other on both sides of the combustion unit from inside the plurality of first catalyst tubes, the plurality of first catalyst tubes positioned on the same side of the combustion unit are positioned parallel to each other along the width direction of the main body, and the plurality of second catalyst tubes positioned on the same side of the combustion unit are positioned parallel to each other along the width direction of the main body, and the plurality of first catalyst tubes and the plurality of second catalyst tubes are positioned symmetrically on both sides of the combustion unit. Claim 2 delete Claim 3 delete Claim 4 A box-type composite reformer according to claim 1, wherein each of the first catalyst tubes is formed in a U-shape, and the plurality of first catalyst tubes are arranged side by side so that the U-shapes face each other. Claim 5 A box-type composite reformer according to claim 1, further comprising: a plurality of inlet pipes connected to each of the plurality of first catalyst tubes and extending to the outside of the main body; and an inlet header connected to the plurality of inlet pipes. Claim 6 A box-type composite reformer according to claim 5, further comprising: a plurality of outlet pipes connected to each of the plurality of second catalyst tubes and extending to the outside of the main body; and an outlet header connected to the plurality of outlet pipes. Claim 7 A box-type composite reformer according to claim 5, characterized in that a flow control unit for controlling the flow rate of hydrocarbon gas flowing into each of the first catalyst tubes is installed between each of the inlet pipes and the inlet headers. Claim 8 A box-type composite reformer according to claim 1, further comprising a plurality of combustion gas discharge pipes each connected to the main body on both sides of the combustion section so as to discharge combustion gas generated in the combustion section. Claim 9 A box-type composite reformer according to claim 1, wherein the combustion unit comprises a plurality of burners, and the plurality of burners are spaced apart along the width direction of the main body. Claim 10 A box-type composite reformer according to claim 9, characterized in that the plurality of burners burn the same fuel. Claim 11 A box-type composite reformer according to claim 9, characterized in that the plurality of burners burn different fuels. Claim 12 A box-type composite reformer according to claim 11, characterized in that some of the plurality of burners receive and burn a portion of the hydrocarbon gas supplied to the first catalyst tube, and the remaining portion receives and burns tail gas from which hydrogen has been separated from the synthesis gas discharged from the second catalyst tube. Claim 13 A box-type composite reformer according to claim 1, wherein the combustion unit comprises a plurality of burners, some of which are disposed on the end surface of the main body and the remaining parts are disposed on the side surface of the main body. Claim 14 A box-type composite reformer according to claim 1, wherein the combustion unit includes a burner installed outside the main body, and combustion occurs inside the main body. Claim 15 A box-type composite reformer according to claim 1, wherein the combustion unit comprises a burner installed outside the main body, a combustion furnace connected to the burner and installed outside the main body, and a connecting duct connecting the combustion furnace and the main body. Claim 16 A box-type composite reformer according to claim 15, characterized in that the connecting duct widens in the width direction of the main body as it goes from the combustion furnace to the main body. Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete

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