Desulfurization unit

Abstract

A desulfurizing device (21) comprises: a flow path through which flows a hydrocarbon fuel containing a sulfur compound; a first desulfurizing agent which is filled into a first desulfurizer (1); a second desulfurizing agent which is filled into a second desulfurizer (2); a cooler (4); and a heater (3). The first desulfurizing agent is provided to the flow path, is constituted by a metal-organic framework having a copper ion and an organic ligand, and removes at least some of the sulfur compound contained in the hydrocarbon fuel. The second desulfurizing agent is provided to the flow path downstream of the first desulfurizing agent in the direction of flow of the hydrocarbon fuel, and among the sulfur compounds contained in the hydrocarbon fuel, removes carbonyl sulfide. The cooler (4) cools the first desulfurizing agent to a temperature that is higher than or equal to the dew point of the hydrocarbon fuel, but lower than or equal to a temperature at which deterioration of the first desulfurizing agent is suppressed. The heater (3) heats the second desulfurizing agent to a temperature that is higher than or equal to a temperature at which carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizing agent.

Description

Technical Field

[0001] The present disclosure relates to a desulfurization device for removing sulfur compounds from hydrocarbon fuels.

Background Art

[0002] Patent Document 1 discloses a configuration for removing sulfur compounds from a hydrocarbon fuel containing sulfur compounds using a metal-organic framework having copper ions and an organic ligand.

[0003] Patent Document 2 discloses a desulfurization device including a first desulfurizing agent for removing sulfur compounds contained in a hydrocarbon fuel and a second desulfurizing agent disposed downstream of the first desulfurizing agent for removing carbonium sulfide contained in the hydrocarbon fuel.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] The present disclosure provides a desulfurization device capable of suppressing a decrease in adsorption performance due to deterioration in water at high temperatures of a first desulfurizing agent, suppressing a decrease in adsorption performance of carbonyl sulfide by a second desulfurizing agent, and reducing the amount of desulfurizing agent and the size of the device.

[0006] The desulfurization device in the present disclosure includes a flow path through which a hydrocarbon fuel containing sulfur compounds flows, a first desulfurizing agent provided in this flow path, a second desulfurizing agent provided in a flow path on the downstream side of the first desulfurizing agent in the flow direction of the hydrocarbon fuel, a cooling unit, and a heater.

[0007] The first desulfurizing agent is composed of a metal-organic framework having copper ions and an organic ligand, and is configured to remove at least a part of the sulfur compounds contained in the hydrocarbon fuel.

[0008] The second desulfurizing agent is configured to remove carbonyl sulfides from the sulfur compounds contained in hydrocarbon fuels.

[0009] The cooling unit is configured to cool the temperature of the first desulfurizer to a temperature above the dew point of the hydrocarbon fuel and below a temperature at which the degradation of the first desulfurizer is suppressed.

[0010] The heater is configured to raise the temperature of the secondary desulfurizer to a temperature above which the carbonyl sulfide contained in the hydrocarbon fuel can be removed by the secondary desulfurizer.

[0011] The desulfurization apparatus in this disclosure suppresses the decrease in adsorption performance due to the degradation of the first desulfurizing agent in water at high temperatures, suppresses the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent, and can reduce the amount of desulfurizing agent and the size of the desulfurization apparatus. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a block diagram showing the configuration of the desulfurization apparatus in Embodiment 1. [Figure 2] Figure 2 is a block diagram showing the configuration of the desulfurization apparatus in Embodiment 2. [Figure 3] Figure 3 is a block diagram showing the configuration of the desulfurization apparatus in Embodiment 3. [Figure 4] Figure 4 is a block diagram showing the configuration of the desulfurization apparatus in Embodiment 4. [Modes for carrying out the invention]

[0013] (Knowledge and other information that formed the basis of this disclosure) Since the time the inventors conceived of this disclosure, desulfurization apparatuses have been known that use a metal-organic structure having copper ions and an organic ligand to remove sulfur compounds from hydrocarbon fuels containing sulfur compounds. This desulfurization apparatus can remove sulfur compounds contained in hydrocarbon fuels simply and effectively.

[0014] Furthermore, a desulfurization apparatus is known that includes a first desulfurizing agent that removes tetrahydrothiophene (hereinafter referred to as THT), which is a part of the sulfur compounds contained in hydrocarbon fuels, and a second desulfurizing agent that is placed downstream of the first desulfurizing agent and removes carbonyl sulfides contained in hydrocarbon fuels. This desulfurization apparatus can effectively remove carbonyl sulfides from the sulfur compounds contained in the fuel gas using the second desulfurizing agent.

[0015] However, metal-organic structures containing copper ions and organic ligands can be destroyed by moisture when hydrocarbon fuels contain water and the temperature is high. Therefore, when metal-organic structures containing copper ions and organic ligands are used as a primary desulfurizing agent, there is a problem in that the adsorption performance of sulfur compounds in the primary desulfurizing agent decreases.

[0016] Furthermore, a problem with the second desulfurizing agent that removes carbonyl sulfide is that its carbonyl sulfide adsorption performance decreases as the temperature drops.

[0017] Therefore, this disclosure provides a desulfurization apparatus that can suppress the decrease in adsorption performance due to the degradation of the first desulfurizing agent in water at high temperatures, suppress the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent, and reduce the amount of desulfurizing agent and the size of the apparatus.

[0018] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted.

[0019] The attached drawings and the following description are provided to enable a person skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0020] (Embodiment 1) Hereinafter, using Figure 1, we will describe the desulfurization apparatus 21 in Embodiment 1, which is an example of a desulfurization apparatus in this disclosure.

[0021] [1-1. Configuration] FIG. 1 is a block diagram showing the configuration of the desulfurization apparatus 21 in Embodiment 1. In FIG. 1, the flow path through which the hydrocarbon fuel containing the sulfur compound flows is indicated by an arrow. The same applies to FIGS. 2 to 4 described later. As shown in FIG. 1, the desulfurization apparatus 21 includes a first desulfurizer 1, a second desulfurizer 2, a heater 3, a cooler 4, and a controller 41. Further, the desulfurization apparatus 21 is configured to supply the hydrocarbon fuel supplied from the outside to the desulfurization apparatus 21 to the fuel utilization device 31 after desulfurizing it with the first desulfurizer 1 and the second desulfurizer 2.

[0022] The first desulfurizer 1 is provided in the middle of the flow path through which the hydrocarbon fuel containing the sulfur compound flows.

[0023] The hydrocarbon fuel in the first embodiment is city gas mainly composed of methane, and contains THT and carbonyl sulfide as sulfur compounds. Further, the hydrocarbon fuel contains 1% by volume of water vapor.

[0024] The first desulfurizer 1 is filled with a first desulfurizing agent that mainly removes THT among the sulfur compounds contained in the hydrocarbon fuel.

[0025] In the first embodiment, as an example of the first desulfurizing agent in the present disclosure, HKUST-1 (manufactured by BASF), which is a metal-organic framework composed of copper ions and benzene-1,3,5-tricarboxylic acid, is used.

[0026] The second desulfurizer 2 is filled with a second desulfurizing agent that removes carbonyl sulfide among the sulfur compounds contained in the hydrocarbon fuel. As shown in FIG. 1, the second desulfurizer 2 is provided in the flow path on the downstream side of the first desulfurizer 1 in the flow direction of the hydrocarbon fuel.

[0027] In the first embodiment, as an example of the second desulfurizing agent in the present disclosure, a metal oxide containing nickel and copper that removes carbonyl sulfide is used.

[0028] Heater 3 is a heater that heats the second desulfurizer 2 so that the temperature of the second desulfurizer is above the temperature at which carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizer.

[0029] Cooler 4 is a cooling fan that cools the first desulfurizer 1 so that the temperature of the first desulfurizer is above the dew point of the hydrocarbon fuel and below the temperature at which the degradation of the first desulfurizer is suppressed.

[0030] The controller 41 controls the operation of the desulfurization apparatus 21. The controller 41 comprises a signal input / output unit (not shown), an arithmetic processing unit (not shown), and a memory unit (not shown) for storing the control program. In other words, the controller 41 has a computer system having a processor and memory. The computer system functions as the controller 41 by the processor executing the control program stored in memory. The control program executed by the processor is assumed to be pre-recorded in the computer system's memory, but it may also be recorded on a non-temporary recording medium such as a memory card and provided, or provided via a telecommunication line such as the Internet.

[0031] Furthermore, the desulfurization unit 21 is covered with an outer casing (not shown).

[0032] [1-2. Operation] The operation of the desulfurization apparatus 21, configured as described above, will be explained below.

[0033] The following operations are performed by the controller 41 controlling the entire desulfurization apparatus 21, including the heater 3 and the cooler 4.

[0034] First, hydrocarbon fuel is supplied to the first desulfurizer 1. In this embodiment 1, the conditions for the hydrocarbon fuel are a flow rate of 3 NL / min, a temperature of 25°C, a water vapor concentration of 1 volume%, and sulfur compound concentrations of 10 ppm for THT and 0.1 ppm for carbonyl sulfide.

[0035] The first desulfurizer 1 primarily removes THT from the sulfur compounds contained in the hydrocarbon fuel. The hydrocarbon fuel that has passed through the first desulfurizer 1 is supplied to the second desulfurizer 2. The second desulfurizer 2 removes carbonyl sulfides that were not removed in the first desulfurizer 1.

[0036] The temperature of the second desulfurizer 2 is controlled by the heater 3 to be 60°C, for example.

[0037] The temperature of the first desulfurizer 1 is controlled by the cooler 4 to be 25°C, for example.

[0038] After passing through the second desulfurizer 2, the hydrocarbon fuel is supplied to the fuel utilization equipment 31 with a sulfur compound concentration of 1 ppb or less.

[0039] The following describes the results of periodically measuring the hydrocarbon fuel downstream of the second desulfurizer 2 by gas chromatography while varying the temperatures of the first desulfurizer 1 and the second desulfurizer 2.

[0040] First, in Example 1, the hydrocarbon fuel downstream of the second desulfurizer 2 was periodically measured by gas chromatography, with the temperature of the first desulfurizer 1 set to 25°C and the temperature of the second desulfurizer 2 set to 60°C, similar to the desulfurization apparatus 21 in Embodiment 1. In Example 1, an increase in the concentration of THT and carbonyl sulfide was detected downstream 1000 hours after the start of the test.

[0041] Next, as Comparative Example 1, the cooler 4 was stopped, and the operation was started so that the first desulfurizer 1 and the second desulfurizer 2 were both at 60°C.

[0042] In Comparative Example 1, when the hydrocarbon fuel downstream of the second desulfurizer 2 was measured periodically by gas chromatography, an increase in THT concentration was detected downstream after 500 hours from the start of the test. In other words, in Comparative Example 1, where the temperature of the first desulfurizer 1 was higher (60°C) compared to the temperature in Example 1 (25°C), a decrease in the adsorption performance of the first desulfurizer due to degradation in water at high temperatures was observed in a relatively short time (500 hours).

[0043] In addition, as Comparative Example 2, the heater 3 was stopped, and the operation was started so that the temperature of the first desulfurizer 1 and the temperature of the second desulfurizer 2 were both 25°C.

[0044] In Comparative Example 2, when the hydrocarbon fuel downstream of the second desulfurizer 2 was measured periodically by gas chromatography, an increase in the concentration of carbonyl sulfide downstream was detected 100 hours after the start of the test. In other words, in Comparative Example 2, where the temperature of the second desulfurizer 2 was lower (25°C) compared to the temperature in Example 1 (60°C), a decrease in the adsorption performance of carbonyl sulfide by the second desulfurizer was observed in a relatively short time (100 hours).

[0045] Furthermore, when the first desulfurizing agent was removed after the test and its BET surface area was measured, the BET surface area for the first desulfurizer 1 operated at a temperature of 25°C (Comparative Example 2) and the BET surface area for the first desulfurizer 1 operated at 60°C (Comparative Example 1) were 90% and 50% of the initial surface area, respectively.

[0046] [1-3. Effects, etc.] As described above, in this embodiment 1, the desulfurization apparatus 21 comprises a flow path through which hydrocarbon fuel containing sulfur compounds flows, a first desulfurization agent, a second desulfurization agent, a cooler 4, and a heater 3.

[0047] The first desulfurizing agent is packed into the first desulfurizer 1 located in the flow path, and is composed of a metal-organic structure having copper ions and an organic ligand, and is configured to remove at least a portion of the sulfur compounds contained in the hydrocarbon fuel.

[0048] The second desulfurizing agent is located in a flow path downstream of the first desulfurizing agent packed in the first desulfurizer 1 in the direction of hydrocarbon fuel flow, and is configured to remove carbonyl sulfide from the sulfur compounds contained in the hydrocarbon fuel.

[0049] Cooler 4 is an example of a cooling unit in this disclosure and is configured to cool the temperature of the first desulfurizer to a temperature above the dew point of the hydrocarbon fuel and below a temperature at which the degradation of the first desulfurizer is suppressed.

[0050] The heater 3 is configured to raise the temperature of the second desulfurizing agent to a temperature above which the carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizing agent.

[0051] As a result, the desulfurization apparatus 21 can suppress the decrease in adsorption performance due to the degradation of the first desulfurizing agent in water at high temperatures, and suppress the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent. Therefore, the amount of desulfurizing agent and the size of the desulfurization apparatus 21 can be reduced.

[0052] (Embodiment 2) Hereinafter, using Figure 2, we will explain the desulfurization apparatus 22 in Embodiment 2, which is an example of a desulfurization apparatus in this disclosure, focusing on the differences from the desulfurization apparatus 21 in Embodiment 1.

[0053] [2-1. Structure] Figure 2 is a block diagram showing the configuration of the desulfurization apparatus 22 in Embodiment 2. As shown in the figure, the desulfurization apparatus 22 in Embodiment 2 differs from the desulfurization apparatus 21 in Embodiment 1 in that it has a fourth desulfurization apparatus 6 in parallel with the third desulfurization apparatus 5 instead of the first desulfurization apparatus 1. Furthermore, the desulfurization apparatus 22 differs from the desulfurization apparatus 21 in that it has a first on-off valve 7 and a second on-off valve 8 upstream and downstream of the third desulfurization apparatus 5, respectively, and a third on-off valve 9 and a fourth on-off valve 10 upstream and downstream of the fourth desulfurization apparatus 6, respectively. In addition, the desulfurization apparatus 22 differs from the desulfurization apparatus 21 in that it has a controller 42 instead of a controller 41.

[0054] Furthermore, the desulfurization device 22 differs from the desulfurization device 21 in that it is connected to the hydrogen generation device 32 instead of the fuel utilization device 31 in Embodiment 1.

[0055] The desulfurization unit 22 is configured to desulfurize hydrocarbon fuel supplied to the desulfurization unit 22 from the outside in either the third desulfurizer 5 or the fourth desulfurizer 6 and the second desulfurizer 2, and then supply it to the hydrogen generation unit 32. That is, the desulfurization unit 22 is equipped with a first on-off valve 7, a second on-off valve 8, a third on-off valve 9, and a fourth on-off valve 10 (hereinafter also referred to as each on-off valve) that allow hydrocarbon fuel to flow through either the third desulfurizer 5 or the fourth desulfurizer 6. Each on-off valve is controlled by a controller 42 to prevent the hydrocarbon fuel from flowing through the other desulfurizer (for example, the fourth desulfurizer 6) while it is flowing through one of the third desulfurizers (for example, the third desulfurizer 5) of the third desulfurizer 5 or the fourth desulfurizer 6.

[0056] Furthermore, the third desulfurizer 5 and the fourth desulfurizer 6 are filled with the same first desulfurizing agent as the first desulfurizer 1 in Embodiment 1, but in half the amount as the first desulfurizer 1. That is, the total amount of first desulfurizing agent used in the desulfurization apparatus 22 in Embodiment 2 is the same as the amount of first desulfurizing agent used in the desulfurization apparatus 21 in Embodiment 1.

[0057] [2-2. Operation] The operation of the desulfurization apparatus 22, configured as described above, will be explained below.

[0058] The following operations are performed by the controller 42 controlling the entire desulfurization apparatus 22, including the heater 3, the cooler 4, and each on / off valve.

[0059] At the start of operation, the first on-off valve 7 and the second on-off valve 8 are open, and the third on-off valve 9 and the fourth on-off valve 10 are closed, and hydrocarbon fuel is supplied to the third desulfurizer 5.

[0060] Similar to Embodiment 1, the conditions for the hydrocarbon fuel in Embodiment 2 are a flow rate of 3 NL / min, a temperature of 25°C, a water vapor concentration of 1 volume%, and sulfur compound concentrations of 10 ppm for THT and 0.1 ppm for carbonyl sulfide.

[0061] 550 hours after the start of operation, the first on-off valve 7 and the second on-off valve 8 are closed, and the third on-off valve 9 and the fourth on-off valve 10 are opened, switching the supply of hydrocarbon fuel to the fourth desulfurizer 6.

[0062] Here, 550h is the time it takes for the THT concentration to increase downstream of the third desulfurizer 5, which was determined in advance through testing.

[0063] Furthermore, the temperature of the second desulfurizer 2 is controlled by the heater 3 to be 60°C, for example.

[0064] The temperatures of the third desulfurizer 5 and the fourth desulfurizer 6 are controlled by the cooler 4 to be 25°C, for example.

[0065] In Example 2, the hydrocarbon fuel downstream of the second desulfurizer 2 was periodically measured by gas chromatography, with the temperatures of the third desulfurizer 5 and the fourth desulfurizer 6 set to 25°C and the temperature of the second desulfurizer 2 set to 60°C, similar to the desulfurization apparatus 22 in Embodiment 2. As a result, in Example 2, an increase in the concentration of THT and carbonyl sulfide downstream was detected 1100 hours after the start of the test. That is, in Example 2, without changing the amount of the first desulfurizing agent used, the elapsed time from the start of the test until an increase in the concentration of THT and carbonyl sulfide downstream was detected was made even longer than in Example 1. In other words, in Example 2, compared to Example 1, further suppression of the decrease in adsorption performance due to degradation of the first desulfurizing agent in water at high temperatures and suppression of the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent were observed.

[0066] [2-3. Effects, etc.] As described above, in this second embodiment, the desulfurization apparatus 22 comprises a flow path through which hydrocarbon fuel containing sulfur compounds flows, a first desulfurization agent, a second desulfurization agent, a cooler 4, and a heater 3.

[0067] The first desulfurizing agent is packed into the third desulfurizer 5 and the fourth desulfurizer 6, which are arranged in parallel to each other in the flow path, and is composed of a metal-organic structure having copper ions and an organic ligand, and is configured to remove at least a portion of the sulfur compounds contained in the hydrocarbon fuel.

[0068] The second desulfurizing agent is provided in the flow path downstream of the first desulfurizing agent packed in the third desulfurizer 5 and the fourth desulfurizer 6 in the direction of hydrocarbon fuel flow, and is configured to remove carbonyl sulfide from the sulfur compounds contained in the hydrocarbon fuel.

[0069] Cooler 4 is an example of a cooling unit in this disclosure, and is provided separately in the third desulfurizer 5 and the fourth desulfurizer 6, respectively, and is configured to cool the temperature of the first desulfurizer to a temperature above the dew point of the hydrocarbon fuel and below a temperature at which the deterioration of the first desulfurizer is suppressed.

[0070] The heater 3 is configured to raise the temperature of the second desulfurizing agent to a temperature above which the carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizing agent.

[0071] As a result, the desulfurization apparatus 22 can suppress the decrease in adsorption performance due to the degradation of the first desulfurizing agent in water at high temperatures, and suppress the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent. Therefore, the amount of desulfurizing agent and the size of the desulfurization apparatus 22 can be reduced.

[0072] Furthermore, as in Embodiment 2, the desulfurization apparatus 22 has a third desulfurizer 5 and a fourth desulfurizer 6, both filled with a first desulfurizing agent, installed in parallel. The desulfurization apparatus 22 includes a first on-off valve 7, a second on-off valve 8, a third on-off valve 9, and a fourth on-off valve 10, which are examples of switching valves in this disclosure that allow hydrocarbon fuel to flow through at least one of the third desulfurizers 5 and the fourth desulfurizer 6. The first on-off valve 7, the second on-off valve 8, the third on-off valve 9, and the fourth on-off valve 10 do not allow hydrocarbon fuel to flow through the other desulfurizers except for that at least one while hydrocarbon fuel is being supplied to at least one of the third desulfurizers 5 and the fourth desulfurizer 6.

[0073] Specifically, the desulfurization apparatus 22 is equipped with a first on-off valve 7 on the upstream side of the third desulfurizer 5 in the branch channel corresponding to the third desulfurizer 5, and a second on-off valve 8 on the downstream side of the third desulfurizer 5 in the branch channel corresponding to the third desulfurizer 5. Furthermore, the desulfurization apparatus 22 is equipped with a third on-off valve 9 on the upstream side of the fourth desulfurizer 6 in the branch channel corresponding to the fourth desulfurizer 6, and a fourth on-off valve 10 on the downstream side of the fourth desulfurizer 6 in the branch channel corresponding to the fourth desulfurizer 6.

[0074] In this case, the first on-off valve 7, the second on-off valve 8, the third on-off valve 9, and the fourth on-off valve 10 open and close so that the hydrocarbon fuel flows through either the third desulfurizer 5 or the fourth desulfurizer 6.

[0075] For example, while hydrocarbon fuel is flowing through the third desulfurizer 5 (hydrocarbon fuel is being supplied to the third desulfurizer 5), the first on-off valve 7 and the second on-off valve 8 are open, and the third on-off valve 9 and the fourth on-off valve 10 are closed, preventing hydrocarbon fuel from flowing through the fourth desulfurizer 6.

[0076] Conversely, while hydrocarbon fuel is flowing through the fourth desulfurizer 6 (hydrocarbon fuel is being supplied to the fourth desulfurizer 6), the third on-off valve 9 and the fourth on-off valve 10 are open, and the first on-off valve 7 and the second on-off valve 8 are closed, preventing hydrocarbon fuel from flowing through the third desulfurizer 5.

[0077] As a result, the desulfurization unit 22 can suppress the decrease in adsorption performance due to degradation by water at high temperatures of the first desulfurizing agent packed in the desulfurizer when hydrocarbon fuel is not flowing through it, and it becomes unnecessary to install extra first desulfurizing agent to compensate for the decrease in adsorption performance. Therefore, the amount of desulfurizing agent and the size of the desulfurization unit 22 can be reduced.

[0078] (Embodiment 3) Hereinafter, using Figure 3, we will explain the desulfurization apparatus 22 in Embodiment 3, which is an example of a desulfurization apparatus in this disclosure, focusing on the differences from the desulfurization apparatus 21 in Embodiment 1.

[0079] [3-1. Structure] Figure 3 is a block diagram showing the configuration of the desulfurization apparatus 23 in Embodiment 3. In the following, the vertical direction when the desulfurization apparatus 23 is installed for use (corresponding to the installation state in this disclosure) may be described as the up and down direction.

[0080] As shown in Figure 3, the desulfurization apparatus 23 in Embodiment 3 differs from the desulfurization apparatus 21 in Embodiment 1 in that it has an intake fan 11, an exhaust port 12, and an intake port 13 instead of a cooler 4. Furthermore, the desulfurization apparatus 23 differs from the desulfurization apparatus 21 in that the first desulfurizer 1 is installed lower than the second desulfurizer 2 in the vertical direction when the desulfurization apparatus 23 is installed, and that it has a controller 43 instead of a controller 41.

[0081] Furthermore, the desulfurization device 23 differs from the desulfurization device 21 in that it is connected to the hydrogen generation device 32 instead of the fuel utilization device 31 in Embodiment 1.

[0082] The desulfurization unit 23 is configured to desulfurize hydrocarbon fuel supplied to the desulfurization unit 23 from an external source using the first desulfurizer 1 and the second desulfurizer 2, and then supply it to the hydrogen generator 32.

[0083] Furthermore, since the desulfurization unit 23 is enclosed and isolated from the outside air, the internal heat causes it to be hotter than the outside air. For example, when the outside air temperature is 25°C, the internal temperature of the desulfurization unit 23 is assumed to be 60°C.

[0084] The exterior is provided with an air intake port 13 for taking in outside air and an exhaust port 12 for discharging the air inside the exterior (the air inside the desulfurization unit 23) to the outside of the exterior (outside the desulfurization unit 23). The intake fan 11 is installed at the air intake port 13 and operates to draw in outside air from the air intake port 13. The intake fan 11 is configured to cool the first desulfurizing agent to a temperature above the dew point of the hydrocarbon fuel and below the temperature at which the deterioration of the first desulfurizing agent is suppressed (for example, 25°C).

[0085] The intake fan 11 (intake port 13) is located below the first desulfurizer 1 in the vertical direction of the desulfurization apparatus 23 in its installed state. The exhaust port 12 is located above the second desulfurizer 2 in the vertical direction of the desulfurization apparatus 23 in its installed state. As described above, the first desulfurizer 1 is installed below the second desulfurizer 2 in the vertical direction of the desulfurization apparatus 23 in its installed state. In other words, the intake fan 11 (intake port 13), exhaust port 12, and first desulfurizer 1 are arranged so that outside air taken into the casing of the desulfurization apparatus 23 by the intake fan 11 cools the first desulfurizer 1 before being discharged outside the casing of the desulfurization apparatus 23 through the exhaust port 12.

[0086] [3-2. Operation] The operation of the desulfurization apparatus 23, configured as described above, will be explained below.

[0087] The following operations are performed by the controller 43 controlling the entire desulfurization apparatus 23, including the intake fan 11.

[0088] The temperature of the first desulfurizer 1 is controlled by the intake fan 11 to be 25°C, for example.

[0089] Other operations are the same as those of the desulfurization apparatus 21 in Embodiment 1 and are therefore omitted.

[0090] [3-3. Effects, etc.] As described above, in this embodiment 3, the desulfurization apparatus 23 comprises a flow path through which hydrocarbon fuel containing sulfur compounds flows, a first desulfurization agent, a second desulfurization agent, an intake port 13, an intake fan 11 and an exhaust port 12 which constitute an example of a cooling section in this disclosure, and a heater 3.

[0091] The first desulfurizing agent is packed into the first desulfurizer 1 located in the flow path, and is composed of a metal-organic structure having copper ions and an organic ligand, and is configured to remove at least a portion of the sulfur compounds contained in the hydrocarbon fuel.

[0092] The second desulfurizing agent is packed into the second desulfurizer 2, which is located in the flow path downstream of the first desulfurizer 1 in the direction of hydrocarbon fuel flow, and is configured to remove carbonyl sulfide from the sulfur compounds contained in the hydrocarbon fuel.

[0093] The intake fan 11 is configured to cool the temperature of the first desulfurizer to a temperature above the dew point of the hydrocarbon fuel and below a temperature at which the degradation of the first desulfurizer is suppressed.

[0094] The heater 3 is configured to raise the temperature of the second desulfurizing agent to a temperature above which the carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizing agent.

[0095] As a result, the desulfurization apparatus 23 can suppress the decrease in adsorption performance due to the degradation of the first desulfurizing agent in water at high temperatures, and suppress the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent. Therefore, the amount of desulfurizing agent and the size of the desulfurization apparatus 23 can be reduced.

[0096] Furthermore, as in this third embodiment, the desulfurization apparatus 23 is equipped with an outer casing to isolate it from the outside air, and includes an air intake port 13, an exhaust port 12, and an intake fan 11 as a cooling section. The air intake port 13 is provided in the outer casing to take in outside air. The exhaust port 12 is provided in the outer casing to discharge the air inside the outer casing to the outside. The intake fan 11 is provided at the air intake port 13 and operates to draw in outside air from the air intake port 13.

[0097] Furthermore, in the desulfurization apparatus 23, the first desulfurizing agent filled in the first desulfurizer 1 is located lower in the vertical direction than the second desulfurizing agent filled in the second desulfurizer 2, in the installed state of the desulfurization apparatus 23. Also, the air intake port 13 (intake fan 11) is located lower in the vertical direction than the first desulfurizing agent filled in the first desulfurizer 1, in the installed state of the desulfurization apparatus 23.

[0098] As a result, the desulfurization unit 23 can cool the first desulfurizing agent relatively efficiently with a relatively simple configuration, and suppress the temperature drop of the second desulfurizing agent. Therefore, a desulfurization unit 23 with a reduced size can be provided at a relatively low cost.

[0099] (Embodiment 4) Hereinafter, using Figure 4, we will explain the desulfurization apparatus 24 in Embodiment 4, which is an example of a desulfurization apparatus in this disclosure, focusing on the differences from the desulfurization apparatus 23 in Embodiment 3.

[0100] [4-1. Structure] Figure 4 is a block diagram showing the configuration of the desulfurization apparatus 24 in Embodiment 4. As shown in the figure, the desulfurization apparatus 24 in Embodiment 4 differs from the desulfurization apparatus 23 in Embodiment 3 shown in Figure 3 in that the first desulfurizer 1 is positioned closer to the exterior than the second desulfurizer 2, and that it is equipped with a controller 44 instead of a controller 43.

[0101] [4-2. Operation] The operation of the desulfurization apparatus 24, configured as described above, will be explained below.

[0102] The following operations are performed by the controller 44 controlling the entire desulfurization unit 24, including the intake fan 11.

[0103] The temperature of the first desulfurizer 1 is controlled by the intake fan 11 to be 25°C, for example.

[0104] Other operations are the same as in Embodiment 1 and will therefore be omitted.

[0105] [4-3. Effects, etc.] As described above, in this embodiment 4, the desulfurization apparatus 24 comprises a flow path through which hydrocarbon fuel containing sulfur compounds flows, a first desulfurization agent, a second desulfurization agent, an intake port 13, an intake fan 11, and an exhaust port 12 which constitute an example of a cooling section in this disclosure, and a heater 3.

[0106] The first desulfurizing agent is packed into the first desulfurizer 1 located in the flow path, and is composed of a metal-organic structure having copper ions and an organic ligand, and is configured to remove at least a portion of the sulfur compounds contained in the hydrocarbon fuel.

[0107] The second desulfurizing agent is packed into the second desulfurizer 2, which is located in the flow path downstream of the first desulfurizer 1 in the direction of hydrocarbon fuel flow, and is configured to remove carbonyl sulfide from the sulfur compounds contained in the hydrocarbon fuel.

[0108] The intake fan 11 is configured to cool the temperature of the first desulfurizer to a temperature above the dew point of the hydrocarbon fuel and below a temperature at which the degradation of the first desulfurizer is suppressed.

[0109] The heater 3 is configured to raise the temperature of the second desulfurizing agent to a temperature above which the carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizing agent.

[0110] As a result, the desulfurization apparatus 24 can suppress the decrease in adsorption performance due to the degradation of the first desulfurizing agent in water at high temperatures, and suppress the decrease in the adsorption performance of carbonyl sulfide by the second desulfurizing agent. Therefore, the desulfurization apparatus 24 can reduce the amount of desulfurizing agent and the size of the desulfurization apparatus 21.

[0111] Furthermore, as in this embodiment 4, the desulfurization apparatus 24 is equipped with an outer casing to isolate it from the outside air, and includes an air intake port 13, an exhaust port 12, and an intake fan 11 as a cooling section. The air intake port 13 is provided in the outer casing to take in outside air. The exhaust port 12 is provided in the outer casing to discharge the air inside the outer casing to the outside. The intake fan 11 is provided at the air intake port 13 and operates to draw in outside air from the air intake port 13.

[0112] Furthermore, in the desulfurization apparatus 24, the first desulfurizing agent filled in the first desulfurizer 1 is positioned closer to the outer casing than the second desulfurizing agent filled in the second desulfurizer 2.

[0113] As a result, the desulfurization unit 24 can cool the first desulfurizing agent relatively efficiently with a relatively simple configuration, and the temperature drop of the second desulfurizing agent can be suppressed. Therefore, a smaller desulfurization unit 24 can be provided at a relatively low cost.

[0114] (Other embodiments) As described above, Embodiments 1 to 4 have been presented as examples of the technology described herein. However, the technology described herein is not limited to these embodiments and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to combine the components described in Embodiments 1 to 4 above to create new embodiments.

[0115] Therefore, other embodiments are illustrated below.

[0116] In Embodiments 1 to 4, city gas mainly composed of methane was used as an example of the hydrocarbon fuel in this disclosure, but LPG (Liquefied Petroleum Gas) or natural gas may also be used.

[0117] Furthermore, while THT is used as an example of a sulfur compound in this disclosure, dimethyl sulfide or tert-butyl mercaptan, which are used as odorants for city gas, may also be used.

[0118] Furthermore, in Embodiment 2, two desulfurizers, the third desulfurizer 5 and the fourth desulfurizer 6, were exemplified as the multiple desulfurizers in this disclosure that are installed in parallel and filled with the first desulfurizing agent, but three or more desulfurizers may be used. In this modification, the desulfurization apparatus needs to be equipped with two on-off valves for each additional desulfurizer.

[0119] Furthermore, in Embodiment 2, four on-off valves, a first on-off valve 7, a second on-off valve 8, a third on-off valve 9, and a fourth on-off valve 10, were exemplified as the switching valves in this disclosure, but for example, a two-way valve may be used. Also, in the desulfurization apparatus in the above modification which includes three or more desulfurizers, for example, a multi-way valve corresponding to the number of desulfurizers may be used.

[0120] Furthermore, since the embodiments described above (1-4) and other embodiments are illustrative of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the scope of the claims or their equivalents. [Industrial applicability]

[0121] This disclosure is applicable to desulfurization equipment that removes sulfur compounds from hydrocarbon fuels. Specifically, this disclosure is applicable to fuel cell systems and hydrogen production equipment that incorporate hydrogen generators that produce hydrogen from city gas or LPG, for example. [Explanation of Symbols]

[0122] 1 First desulfurizer 2 Second desulfurizer 3 Heater 4 Cooler 5 Third desulfurizer 6 Fourth desulfurizer 7. First shut-off valve 8. Second shut-off valve 9. Third shut-off valve 10. Fourth on / off valve 11 Intake fan 12 Exhaust vents 13 Air intake 21 Desulfurization equipment 22 Desulfurization equipment 23 Desulfurization equipment 24 Desulfurization equipment 31 Fuel utilization equipment 32 Hydrogen generator 41 Controller 42 Controllers 43 Controller 44 Controllers

Claims

1. A flow path through which hydrocarbon fuels containing sulfur compounds flow, A first desulfurizing agent is provided in the aforementioned flow path and is composed of a metal-organic structure having copper ions and an organic ligand, which removes at least a portion of the sulfur compounds contained in the hydrocarbon fuel. A second desulfurizing agent is provided in the flow path downstream of the first desulfurizing agent in the flow direction of the hydrocarbon fuel, and removes carbonyl sulfide from the sulfur compounds contained in the hydrocarbon fuel. A cooling unit that cools the temperature of the first desulfurizing agent to a temperature above the dew point of the hydrocarbon fuel and below a temperature at which deterioration of the first desulfurizing agent is suppressed, A heater that raises the temperature of the second desulfurizing agent to a temperature at which carbonyl sulfide contained in the hydrocarbon fuel can be removed by the second desulfurizing agent, A desulfurization apparatus equipped with an exterior so as to be isolated from the outside air, The cooling unit comprises an intake port provided in the exterior for taking in outside air, an exhaust port provided in the exterior for discharging air from inside the exterior to the outside, and an intake fan that operates to draw in outside air through the intake port. The first desulfurizing agent is located lower in the vertical direction than the second desulfurizing agent in the installed state of the desulfurization apparatus. The air intake port is located below the first desulfurizing agent in the vertical direction in the installed state of the desulfurization apparatus. A desulfurization apparatus characterized by the following features.

2. Multiple desulfurizers filled with the aforementioned first desulfurizing agent are installed in parallel. A switching valve is provided to allow the hydrocarbon fuel to flow through at least one of the plurality of desulfurizers. The switching valve prevents the hydrocarbon fuel from flowing to the other desulfurizers among the plurality of desulfurizers, except for at least one of the plurality of desulfurizers, while the hydrocarbon fuel is being supplied to at least one of the plurality of desulfurizers. The desulfurization apparatus according to claim 1, characterized by the features described above.

3. The first desulfurizing agent is positioned closer to the outer casing than the second desulfurizing agent. The desulfurization apparatus according to claim 1, characterized by the features described above.

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