Fuel processing system using plasma burner and fuel processing method using same

Abstract

Disclosed in an embodiment of the present invention is a fuel processing system using a plasma burner, the fuel processing system comprising: a main fuel supply unit that supplies flame-retardant fuel; a plasma burner that generates heat by burning the flame-retardant fuel supplied from the main fuel supply unit; and a catalyst reactor that reforms or decomposes the flame-retardant fuel supplied from the main fuel supply unit by using a catalyst, wherein a reaction of reforming or decomposing the flame-retardant fuel is an endothermic reaction, and the catalyst reactor can receive heat from the plasma burner.

Description

Fuel processing system using a plasma burner and fuel processing method using the same

[0001] The present invention relates to a fuel treatment system using a plasma burner for reforming or decomposing fuel and a fuel treatment method using the same.

[0002] As a measure against global warming, efforts are being made to reduce greenhouse gases. For example, attempts are being made to convert biomass, organic polymer waste, and the like into liquid fuels or carbon materials.

[0003] Furthermore, in modern life where hydrogen (H2) vehicles are increasingly being used, hydrogen production technology has become important. As for methods to produce hydrogen, it is possible to produce hydrogen in large quantities by reforming methane or cracking ammonia as a raw material.

[0004] However, since the reforming of methane and the decomposition of ammonia are endothermic reactions requiring a large amount of heat, directly supplying ammonia or biogas to the combustion burner may result in a low heat output and a prolonged flame length, which can cause problems such as unstable combustion.

[0005] The object of the present invention is to provide a fuel treatment system and a fuel treatment method using a plasma burner capable of efficiently reforming or decomposing biogas or ammonia, which are flame-retardant gases.

[0006] A fuel processing system using a plasma burner according to one embodiment of the present invention comprises: a main fuel supply unit for supplying flame-retardant fuel; a plasma burner for generating heat by burning the flame-retardant fuel supplied from the main fuel supply unit; and a catalytic reactor for reforming or decomposing the flame-retardant fuel supplied from the main fuel supply unit using a catalyst, wherein the reaction for reforming or decomposing the flame-retardant fuel is an endothermic reaction, and the catalytic reactor may receive heat from the plasma burner.

[0007] A fuel treatment method using a plasma burner according to one embodiment of the present invention may include a plasma combustion step of supplying fuel and air to a plasma burner to generate plasma and burning the fuel to generate a flame, a catalytic reaction step of using the heat generated in the plasma combustion step and a catalyst to decompose or reform the fuel to generate a treatment gas, and a hydrogen separation step of separating hydrogen contained in the treatment gas.

[0008] As described above, a fuel treatment system using a plasma burner according to one embodiment of the present invention can stably burn flame-retardant fuel using a plasma burner and supply heat to a catalytic reactor.

[0009] FIG. 1 is a schematic diagram illustrating a fuel processing system according to one embodiment of the present invention.

[0010] Figure 2 is a cross-sectional view schematically illustrating an example of the plasma burner of Figure 1.

[0011] Figure 3 is a flowchart for explaining the fuel processing method of the fuel processing system of Figure 1.

[0012] FIG. 4 is a schematic diagram illustrating a fuel processing system according to another embodiment of the present invention.

[0013] Figure 5 is a flowchart for explaining the fuel processing method of the fuel processing system of Figure 4.

[0014] FIG. 6 is a schematic diagram illustrating a fuel processing system according to another embodiment of the present invention.

[0015] A fuel processing system using a plasma burner according to one aspect of the present invention comprises: a main fuel supply unit for supplying flame-retardant fuel; a plasma burner for generating heat by burning the flame-retardant fuel supplied from the main fuel supply unit; and a catalytic reactor for reforming or decomposing the flame-retardant fuel supplied from the main fuel supply unit using a catalyst, wherein the reaction for reforming or decomposing the flame-retardant fuel is an endothermic reaction, and the catalytic reactor may receive heat from the plasma burner.

[0016] In this embodiment, the catalyst reactor may be arranged to surround the plasma burner.

[0017] In this embodiment, a steam supply pipe for supplying steam may be connected to the catalytic reactor.

[0018] In this embodiment, the flame-retardant fuel may be biogas or ammonia.

[0019] In this embodiment, an external fuel supply pipe for supplying combustible fuel may be further connected to the plasma burner.

[0020] In this embodiment, a hydrogen separator for separating hydrogen from the treatment gas discharged from the catalytic reactor may be further included.

[0021] In this embodiment, a circulation supply pipe may be further included to supply at least a portion of the byproduct gas or purified hydrogen discharged from the hydrogen separator to the plasma burner.

[0022] In this embodiment, the flame-retardant fuel, the byproduct gas discharged from the hydrogen separator, and the purified hydrogen can be supplied together to the plasma burner and combusted.

[0023] In this embodiment, the device may further include a hydrogen tank for storing the hydrogen discharged from the hydrogen separator and a hydrogen supply pipe for supplying the hydrogen stored in the hydrogen tank to the plasma burner.

[0024] In this embodiment, the flame-retardant fuel is biogas, and a water-gas shift reactor may be further included between the hydrogen separator and the catalytic reactor.

[0025] In the present embodiment, the plasma burner may include a housing having an internal space and a discharge electrode inserted inside the housing.

[0026] In this embodiment, a swirler that forms a vortex of incoming air may be installed in the housing.

[0027] In this embodiment, an external heater surrounding the catalyst reactor may be further included.

[0028] In this embodiment, the external heater can receive combustion gas from the plasma burner and heat the catalytic reactor.

[0029] A fuel treatment method using a plasma burner according to another aspect of the present invention may include a plasma combustion step of supplying fuel and air to a plasma burner to generate plasma and burning the fuel to generate a flame, a catalytic reaction step of using the heat generated in the plasma combustion step and a catalyst to decompose or reform the fuel to generate a treatment gas, and a hydrogen separation step of separating hydrogen contained in the treatment gas.

[0030] The hydrogen separation step according to one embodiment of the present invention can supply the discharged byproduct gas and some hydrogen to the plasma burner.

[0031] The hydrogen separation step according to one embodiment of the present invention can separate hydrogen using a pressure swing adsorption method.

[0032] The plasma combustion step according to one embodiment of the present invention can form a flame by burning biogas or ammonia.

[0033] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0034] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that in the accompanying drawings, identical components are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that may obscure the essence of the present invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted.

[0036] A fuel processing system according to the first embodiment of the present invention will be described below.

[0037] FIG. 1 is a schematic diagram illustrating a fuel processing system according to one embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view illustrating an example of a plasma burner of FIG. 1.

[0038] Referring to FIGS. 1 and 2, a fuel processing system (101) according to one embodiment of the present invention may include a plasma burner (110), a catalytic reactor (120), a water-gas shift reactor (131), a hydrogen separator (132), and a main fuel supply unit (141).

[0039] The fuel processing system (101) is a system that extracts hydrogen by decomposing a flame-retardant fuel using a catalyst and heat. The fuel processing system (101) may be composed of a system that produces hydrogen by reforming or decomposing biogas.

[0040] The plasma burner (110) generates plasma to burn biogas and generate heat. The plasma burner (110) can be composed of direct current arc plasma, alternating current arc plasma, etc.

[0041] Additionally, an external fuel supply pipe (145) is connected to the plasma burner (110), and a combustible fuel with a high octane rating, such as natural gas, may be supplied through the external fuel supply pipe (145).

[0042] A plasma burner (110) may include a housing (10) having an internal space, a discharge electrode (20) inserted inside the housing (10), and a swirler (30) disposed on one side of the housing (10).

[0043] The housing (10) is formed in a tubular shape having an internal space and can be grounded. An inlet (15) for introducing fuel and air may be formed at one end of the housing (10). A swirler (30) for inducing rotational flow may be installed in the inlet (15).

[0044] The discharge electrode (20) is inserted inside the housing (10) and can extend along the longitudinal direction of the housing (10). The discharge electrode (20) can be charged with a preset discharge voltage, and a DC or AC power source can be connected to the discharge electrode (20).

[0045] An arc (AC) is formed between the discharge electrode (20) and the inner wall of the housing (10), and the fuel is heated by the arc (AC) to form a flame (50). A stable flame (50) can be formed using flame-retardant fuel by the high-temperature arc (AC).

[0046] Biogas and air can be introduced into the inlet (15), and the biogas and air introduced through the inlet (15) can form a vortex by the swirler (30). Thus, the biogas and air can rotate the arc by the rotational vortex within the housing (110), and the flame (50) can be stabilized.

[0047] The catalytic reactor (120) may be formed to surround the plasma burner (110). The catalytic reactor (120) includes a plurality of catalysts (121), and the catalysts (121) may be reforming catalysts, precious metal catalysts, or non-precious metal catalysts. The catalysts (121) may be in the form of beads or cartridges. The catalysts (121) may include a support and a catalyst layer coated on the support, and various structures and materials for decomposing fuel may be applied.

[0048] The catalytic reactor (120) reforms or decomposes fuel to produce a treatment gas, and the treatment gas can be transferred to a water-gas shift reactor (131). The treatment gas may consist of a reformed gas. For example, if the fuel is CH4, the CH4 can be reformed into carbon monoxide (CO) and hydrogen by a catalytic reaction as shown in Chemical Formula 1 below.

[0049] [Chemical Formula 1]

[0050] CH4 + H2O → CO + 3H2(ΔH>0)

[0051] The main fuel supply unit (141) supplies fuel to the catalytic reactor (120) and the plasma burner (110), and can be connected to the catalytic reactor (120) and the plasma burner (110) via a fuel supply pipe (142). The main fuel supply unit (141) can supply biogas to the catalytic reactor (120) and the plasma burner (110).

[0052] Additionally, steam may be supplied to the catalytic reactor (120). A steam supply pipe (146) for supplying steam may be connected to the catalytic reactor (120). The steam supplied through the steam supply pipe (146) may participate in the steam reforming reaction.

[0053] A water-gas shift reactor (131) is connected to a catalytic reactor (120) to receive a treatment gas, which is a reforming gas produced in the catalytic reactor (120), and water-gas shifts (WGS) the treatment gas to obtain a mixture of hydrogen and carbon dioxide gas. The water-gas shift reaction is a process that produces hydrogen by reacting carbon monoxide produced in the reforming reaction with water vapor as shown in Chemical Formula 2 below.

[0054] [Chemical Formula 2]

[0055] CO + H2O → CO2 + H2(ΔH<0)

[0056] The heat exchanger (136) cools the treatment gas discharged from the water-gas shift reactor (131). The heat exchanger (136) can cool the treatment gas using air and supply the air to the catalytic reactor (120) to heat the catalytic reactor (120). Additionally, the heat exchanger (136) can cool the treatment gas using biogas and supply the heated biogas to the catalytic reactor (120).

[0057] The hydrogen separator (132) receives treatment gas from the heat exchanger (136) and separates hydrogen, byproduct gas, and unreacted fuel. The hydrogen separator (132) can separate hydrogen using a pressure swing adsorption (PSA) method, or it can separate hydrogen using a hydrogen separation membrane. The hydrogen separator (132) can be made of various structures, and the present invention is not limited thereto.

[0058] The purified hydrogen separated from the hydrogen separator (132) can be moved to a storage facility or supplied to a consumption site through piping. The hydrogen separated from the hydrogen separator (132) can be stored in a hydrogen tank (133). A hydrogen supply pipe (137) can be connected to the hydrogen tank (133) to supply the hydrogen stored in the hydrogen tank (133) to a plasma burner (110).

[0059] The circulation supply pipe (135) connects the hydrogen separator (132) and the plasma burner (110) and can supply at least a portion of the byproduct gas discharged from the hydrogen separator (132) and purified hydrogen to the plasma burner (110). The byproduct gas discharged from the hydrogen separator (132) may contain hydrogen and carbon dioxide. The byproduct gas and purified hydrogen can be burned together with biogas in the plasma burner (110).

[0060] The separation efficiency in the hydrogen separator (132) can be lowered to increase the hydrogen content in the byproduct gas. The byproduct gas may contain about 75% to 90% carbon dioxide and 10% to 25% hydrogen. When the byproduct gas is supplied to the plasma burner (110), the flame-retardant fuel can be burned under conditions of excess carbon dioxide, and the flame can be stabilized under conditions of excess carbon dioxide.

[0061] Meanwhile, air or oxygen is injected while forming a vortex within the plasma burner (110), but byproduct gas and biogas may be supplied through the inlet (15), or through the inner surface of the housing (10) or the discharge electrode (20).

[0062] Figure 3 is a flowchart for explaining the fuel processing method of the fuel processing system of Figure 1.

[0063] Referring together to FIGS. 1 to 3, a fuel treatment method according to one embodiment of the present invention may include a plasma combustion step (S101), a catalytic reaction step (S102), and a hydrogen separation step (S103).

[0064] The plasma combustion step (S101) can generate plasma such as direct current arc plasma or alternating current arc plasma by supplying fuel and air to the plasma burner (110). Additionally, the plasma combustion step (S101) can generate a flame (50) by burning fuel. The plasma combustion step (S101) can generate a flame (50) and heat by burning biogas, which is a flame-retardant fuel. As an optional embodiment, the plasma combustion step (S101) may burn a combustible gas, such as natural gas, supplied from an external fuel supply pipe (145).

[0065] The catalytic reaction step (S102) reforms the fuel using the heat generated in the plasma combustion step (S101) and the catalyst. The catalytic reaction step (S102) can reform the biogas by supplying it as fuel to a catalytic reactor (120) containing the catalyst to produce a treated gas containing hydrogen.

[0066] The hydrogen separation step (S103) separates hydrogen contained in the treatment gas generated in the catalytic reactor (120). The hydrogen separation step (S103) can obtain a mixture of hydrogen and carbon dioxide gas by performing a water-gas shift (WGS) on the treatment gas. Additionally, the hydrogen separation step (S103) can separate hydrogen in various ways, such as a pressure swing adsorption method. The hydrogen separation step (S103) can transfer the discharged byproduct gas and some hydrogen to the plasma burner (110).

[0067] FIG. 4 is a schematic diagram illustrating a fuel processing system according to another embodiment of the present invention.

[0068] Referring to FIG. 4, the fuel processing system (102) according to the present invention may include a plasma burner (110), a catalytic reactor (120), a heat exchanger (134), a hydrogen separator (132), and a main fuel supply unit (141).

[0069] The plasma burner (110) can generate plasma to burn fuel and generate heat. The plasma burner (110) can be composed of direct current arc plasma, alternating current arc plasma, etc. The plasma burner (110) can form a flame by burning ammonia, which is a flame-retardant fuel.

[0070] Additionally, an external fuel supply pipe (145) is connected to the plasma burner (110), and a combustible fuel with a high octane rating, such as natural gas, may be supplied through the external fuel supply pipe (145).

[0071] The catalytic reactor (120) may be formed to surround the plasma burner (110). The catalytic reactor (120) includes a plurality of catalysts (121) and decomposes ammonia to produce a treatment gas containing hydrogen as shown in Chemical Formula 3 below. Here, the catalyst (121) may be composed of a decomposition catalyst.

[0072] [Chemical Formula 3]

[0073] 3NH3→ N2+ 3H2(ΔH>0)

[0074] The main fuel supply unit (141) supplies fuel to the catalytic reactor (120) and the plasma burner (110), and can be connected to the catalytic reactor (120) and the plasma burner (110) via a fuel supply pipe (142). The main fuel supply unit (141) can supply ammonia to the catalytic reactor (120) and the plasma burner (110).

[0075] The heat exchanger (134) is connected to the catalytic reactor (120) to receive the treatment gas generated in the catalytic reactor (120) and performs heat exchange with the catalytic reactor (120). The heat exchanger (134) can cool the treatment gas and supply the air used to cool the treatment gas to the catalytic reactor (120). Additionally, the heat exchanger (134) can cool the treatment gas using ammonia and supply the heated ammonia to the catalytic reactor (120).

[0076] The hydrogen separator (132) receives processing gas from the heat exchanger (134) and separates hydrogen, byproduct gas, and unreacted fuel. The hydrogen separator (132) can separate hydrogen using a pressure swing adsorption (PSA) method, or it can separate hydrogen using a hydrogen separation membrane. The hydrogen separator (132) can be made of various structures, and the present invention is not limited thereto.

[0077] Hydrogen separated from the hydrogen separator (132) can be stored in a hydrogen tank (133). A hydrogen supply pipe (137) can be connected to the hydrogen tank (133) to supply the hydrogen stored in the hydrogen tank (133) to a plasma burner (110).

[0078] The circulation supply pipe (135) connects the hydrogen separator (132) and the plasma burner (110) and can supply the byproduct gas discharged from the hydrogen separator (132) and some hydrogen to the plasma burner (110). The byproduct gas discharged from the hydrogen separator (132) may contain hydrogen and nitrogen. The byproduct gas and hydrogen may be burned together with ammonia in the plasma burner (110).

[0079] Figure 5 is a flowchart for explaining the fuel processing method of the fuel processing system of Figure 4.

[0080] Referring to FIGS. 4 and FIGS. 5 together, the fuel treatment method according to the present embodiment may include a plasma combustion step (S201), a catalytic reaction step (S202), and a hydrogen separation step (S203).

[0081] The plasma combustion step (S201) can generate plasma using direct current arc plasma, alternating current arc plasma, etc., and burn fuel. The plasma combustion step (S201) can generate heat by burning ammonia, which is a flame-retardant fuel.

[0082] The catalytic reaction step (S202) decomposes ammonia using the heat generated in the plasma combustion step (S201). The catalytic reaction step (S202) can decompose ammonia to produce a treatment gas containing hydrogen.

[0083] The hydrogen separation step (S203) separates hydrogen contained in the treatment gas generated in the catalytic reactor (120). The hydrogen separation step (S203) can heat exchange the treatment gas with the catalytic reactor (120). Additionally, the hydrogen separation step (S203) can separate hydrogen in various ways, such as a pressure swing adsorption method. The hydrogen separation step (S203) can transfer the discharged byproduct gas and some hydrogen to the plasma burner (110).

[0084] FIG. 6 is a schematic diagram illustrating a fuel processing system according to another embodiment of the present invention.

[0085] Referring to FIG. 6, the fuel processing system (103) according to the present invention may include a plasma burner (110), a catalytic reactor (120), a water-gas shift reactor (131), a hydrogen separator (132), a main fuel supply unit (141), and an external heater (160).

[0086] The fuel processing system (102) according to FIG. 6 has the same structure as the fuel processing system (101 of FIG. 1) shown and described in FIG. 1, except for the external heater (160), so a redundant description of the same configuration is omitted.

[0087] The external heater (160) receives combustion gas from the plasma burner (110) and may include a tube that surrounds the catalytic reactor (120). The external heater (160) may be formed to extend in a circumferential direction around the catalytic reactor (120) and wrap the catalytic reactor (120) in a spiral shape. Accordingly, the catalytic reactor (120) can be efficiently heated using the heat of the high-temperature combustion gas discharged from the plasma burner (110).

[0088] For example, an external heater (160) may be attached to the outer surface of the catalytic reactor (120) via a thermally conductive adhesive. For another example, the external heater (160) may be inserted inside the catalytic reactor (120).

[0089] Although an embodiment of the present invention has been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention.

Claims

1. Main fuel supply unit supplying flame-retardant fuel; A plasma burner that generates heat by burning the flame-retardant fuel supplied from the main fuel supply unit; and A catalytic reactor that modifies or decomposes the flame-retardant fuel supplied from the main fuel supply unit using a catalyst; The reaction for modifying or decomposing the above flame-retardant fuel is an endothermic reaction, and The above catalytic reactor is a fuel processing system using a plasma burner that receives heat from the above plasma burner.

2. In Paragraph 1, The above catalyst reactor is a fuel processing system using a plasma burner arranged to surround the plasma burner.

3. In Paragraph 2, A fuel processing system using a plasma burner connected to a steam supply pipe that supplies steam to the above-mentioned catalytic reactor.

4. In Paragraph 1, The above flame-retardant fuel is a fuel processing system using a plasma burner, which is biogas or ammonia.

5. In Paragraph 1, A fuel processing system using a plasma burner in which an external fuel supply pipe for supplying combustible fuel is further connected to the above plasma burner.

6. In Paragraph 1, A fuel treatment system using a plasma burner further comprising a hydrogen separator for separating hydrogen from the treatment gas discharged from the above-mentioned catalytic reactor.

7. In Paragraph 6, A fuel processing system using a plasma burner, further comprising a circulation supply pipe that supplies at least a portion of the byproduct gas or purified hydrogen discharged from the hydrogen separator to the plasma burner.

8. In Paragraph 7, A fuel processing system using a plasma burner in which the flame-retardant fuel, the byproduct gas discharged from the hydrogen separator, and purified hydrogen are supplied together and combusted in the plasma burner.

9. In Paragraph 6, A fuel processing system using a plasma burner, further comprising a hydrogen tank for storing the hydrogen discharged from the hydrogen separator and a hydrogen supply pipe for supplying the hydrogen stored in the hydrogen tank to the plasma burner.

10. In Paragraph 6, The above flame-retardant fuel is biogas, and A fuel processing system using a plasma burner that further includes a water-gas shift reactor between the hydrogen separator and the catalytic reactor.

11. In Paragraph 1, The above plasma burner is a fuel processing system using a plasma burner comprising a housing having an internal space and a discharge electrode inserted inside the housing.

12. In Paragraph 11, A fuel processing system using a plasma burner installed in the above housing, which forms a swirler of incoming air.

13. In Paragraph 1, A fuel processing system using a plasma burner further comprising an external heater surrounding the above-mentioned catalyst reactor.

14. In Paragraph 13, The above external heater is a fuel processing system using a plasma burner that receives combustion gas from the plasma burner and heats the catalytic reactor.

15. A plasma combustion step of supplying fuel and air to a plasma burner to generate plasma and burning the fuel to generate a flame; A catalytic reaction step for decomposing or reforming the fuel using heat and a catalyst generated in the above plasma combustion step to produce a treatment gas; and A fuel treatment method using a plasma burner comprising: a hydrogen separation step for separating hydrogen contained in the above-mentioned treatment gas.

16. In Paragraph 15, The above hydrogen separation step is a fuel treatment method using a plasma burner that supplies the discharged byproduct gas and some hydrogen to the plasma burner.

17. In Paragraph 15, The above hydrogen separation step is a fuel processing method using a plasma burner that separates hydrogen by a pressure swing adsorption method.

18. In Paragraph 15, The above plasma combustion step is a fuel treatment method using a plasma burner that forms a flame by burning biogas or ammonia.

Images