Marine engine fuel supply device

Abstract

To provide a marine engine fuel supply device capable of supplying fuel containing methane CH4 and hydrogen H2 to a marine engine without using a hydrogen storage tank.SOLUTION: A marine engine fuel supply device comprises: an LPG reformer 40 (reforming device) that uses LPG (liquefied petroleum gas) as a raw material to produce methane-rich gas containing methane CH4, hydrogen H2, and carbon dioxide CO2; and a CO2 separator 50 (removal device) that removes part of carbon dioxide contained in the methane-rich gas produced by the LPG reformer 40 and supplies the gas to a marine engine. The methane-rich gas produced by the LPG reformer 40 has a carbon dioxide (CO2) concentration of less than 20 vol% and a hydrogen (H2) concentration of 10 vol% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a marine engine fuel supply system, and more particularly to a marine engine fuel supply system that supplies fuel to a lean-burn marine engine. [Background technology]

[0002] Conventionally, there has been a marine engine fuel supply device that supplies fuel gas to a marine engine by reforming liquefied petroleum gas (LPG) to increase the methane concentration (see, for example, JP 2019-74053 A (Patent Document 1)).

[0003] In order to reduce carbon dioxide emissions from the above-mentioned marine engines, it has been considered to supply liquefied natural gas (LNG), which is mainly composed of methane (CH4), and hydrogen (H2) to the marine engine to perform hydrogen co-combustion. In a marine engine fuel supply system that supplies LNG and hydrogen (H2) as fuel to a marine engine, LNG from an LNG tank and hydrogen (H2) from a hydrogen storage tank are supplied to the intake port of the marine engine, respectively. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-74053 Summary of the Invention [Problem to be solved by the invention]

[0005] The marine engine fuel supply system, which supplies LNG and hydrogen H2 as fuel to a marine engine, requires a hydrogen supply source such as a hydrogen storage tank, which poses the problem of the hydrogen supply source taking up a large proportion of the onboard space on the ship.

[0006] Therefore, an object of the present invention is to provide a marine engine fuel supply device that can supply fuel containing methane CH4 and hydrogen H2 to a marine engine without using a hydrogen supply source such as a hydrogen storage tank. [Means for solving the problem]

[0007] A marine engine fuel supply device according to one aspect of the present invention includes: a reformer that uses liquefied petroleum gas as a raw material to produce a methane-rich gas containing methane, hydrogen, and carbon dioxide; a removal device that removes part or all of the carbon dioxide contained in the methane-rich gas produced by the reformer and supplies the gas to a marine engine; Equipped with The methane-rich gas produced in the reformer has a carbon dioxide concentration of less than 20 vol % and a hydrogen concentration of 10 vol % or more.

[0008] According to the above configuration, the methane-rich gas produced in the reformer contains a carbon dioxide concentration of less than 20 vol% and a hydrogen concentration of 10 vol% or more. By removing some or all of the carbon dioxide contained in this methane-rich gas using the removal device to reduce the carbon dioxide concentration, the methane and hydrogen concentrations in the methane-rich gas are increased. This allows the methane-rich gas with increased methane and hydrogen concentrations to be supplied to a marine engine as fuel without using a hydrogen supply source such as a hydrogen storage tank. Furthermore, by reducing the carbon dioxide concentration in the methane-rich gas supplied to the marine engine, the carbon dioxide concentration in the exhaust gas can be reduced.

[0009] In one embodiment, the marine engine fuel supply device further comprises: The methane-rich gas supplied from the removal device to the marine engine has a carbon dioxide concentration of 5 vol % or less.

[0010] According to the above embodiment, by setting the carbon dioxide concentration in the methane-rich gas supplied from the removal device to the marine engine to be 5 vol% or less, the hydrogen concentration contained in the methane-rich gas is further increased, and the combustion efficiency of mixed combustion of methane and hydrogen is improved.

[0011] In one embodiment, the marine engine fuel supply device further comprises: The removal device removes carbon dioxide contained in the methane-rich gas by utilizing water vapor from the exhaust gas economizer.

[0012] According to the above embodiment, the water vapor from the exhaust gas economizer is used to remove carbon dioxide contained in the methane-rich gas using, for example, a removal device that uses a CO separation membrane, so that the heat of the exhaust gas can be used to generate water vapor without providing a separate water vapor generation device. [Effects of the Invention]

[0013] As is apparent from the above, according to the present invention, it is possible to realize a marine engine fuel supply device that can supply a fuel containing methane and hydrogen to a marine engine without using a hydrogen supply source such as a hydrogen storage tank. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing the configuration of a fuel supply system using a marine engine fuel supply device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A marine engine fuel supply system according to the present invention will now be described in detail with reference to the accompanying drawings.

[0016] FIG. 1 is a schematic diagram showing the configuration of a fuel supply system using a marine engine fuel supply device according to one embodiment of the present invention. The marine engine fuel supply device of this embodiment uses propane C3H8 and butane C4H 10It is installed on LPG carriers that transport LPG (Liquefied Petroleum Gas), which is mainly composed of these substances.

[0017] As shown in Figure 1, the marine engine fuel supply system of this embodiment includes an LPG reformer 40 and a CO2 separator 50. The LPG reformer 40 is an example of a reformer. The CO2 separator 50 is an example of a removal device. In Figure 1, the pump 20, vaporizer 30, and exhaust gas economizer 70 are facilities of an LPG carrier.

[0018] In the marine engine fuel supply device, LPG (liquid) is supplied from an LPG storage tank 10 to a vaporizer 30 by a pump 20. The vaporizer 30 vaporizes the LPG (liquid) and supplies it to an LPG reformer 40.

[0019] The LPG reformer 40 uses the steam from the exhaust gas economizer 70 and the LPG (gas) from the vaporizer 30 as raw materials and converts them into a methane-rich gas (reformed gas) containing methane CH4, hydrogen H2, and carbon dioxide CO2. The LPG reformer 40 uses the LPG and steam as raw materials and converts them into a reformed gas whose main component is methane CH4 through a methanation reaction using a reforming catalyst (nickel Ni, ruthenium Ru, etc.).

[0020] Here, the concentration of hydrogen (H2) in the methane-rich gas produced is increased by controlling the conditions of the reforming process, such as the reaction temperature (for example, 400°C to 500°C) and the amount of steam in the LPG reformer 40. The higher the concentration of hydrogen (H2) contained in the methane-rich gas, the less carbon dioxide (CO2) is contained in the exhaust gas from the marine engine 60, making it possible to reduce emissions of carbon dioxide (CO2), a greenhouse gas.

[0021] The CO2 separator 50 removes a portion of the carbon dioxide CO2 contained in the methane-rich gas from the LPG reformer 40. In this embodiment, the CO2 separator 50 removes the carbon dioxide CO2 by separating it from the methane-rich gas using water vapor and a CO2 separation membrane.

[0022] Here, it is desirable to control the amount of carbon dioxide CO2 removed in the CO2 separator 50 so that the weight ratio of hydrogen H2 to methane CH4 in the methane-rich gas is about 35 / 60. Furthermore, the carbon dioxide CO2 removed from the methane-rich gas by the CO2 separator 50 is not emitted into the atmosphere but is stored using well-known storage technology.

[0023] Next, the methane-rich gas from which a portion of the carbon dioxide CO2 has been removed by the CO2 separator 50 is supplied to the marine engine 60. Note that the methane-rich gas from which a portion of the carbon dioxide CO2 has been removed by the CO2 separator 50 may be stored in a buffer tank, and then the methane-rich gas may be supplied to the marine engine 60 from the buffer tank.

[0024] The marine engine 60 includes a gas injection valve 62 having an injection nozzle 62a that injects methane-rich gas as fuel into an intake port 61, a fuel injection valve 63 that injects heavy oil A, a cylinder 64, and a piston 65 housed in the cylinder 64. The marine engine 60 is a dual fuel engine that can switch between diesel mode operation using heavy oil A as fuel and gas mode operation using methane-rich gas as fuel depending on the situation. In gas mode operation, efficient lean combustion is performed.

[0025] During diesel mode operation, heavy oil A is injected from the fuel injection valve 63 into the combustion chamber 66. On the other hand, during gas mode operation, methane-rich gas is injected into the intake port 61 from the injection nozzle 62a of the gas injection valve 62.

[0026] The exhaust gas economizer 70 generates steam by utilizing the heat of the exhaust gas from the marine engine 60. The steam generated by the exhaust gas economizer 70 is used in the LPG reformer 40, which converts LPG into methane-rich gas, and also in the CO2 separator 50, which removes carbon dioxide CO2 from the methane-rich gas.

[0027] In this embodiment, the methane-rich gas produced by the LPG reformer 40 has a carbon dioxide CO2 concentration of less than 20 vol% and a hydrogen H2 concentration of 10 vol% or more. In addition, the methane-rich gas supplied from the CO2 separator 50 to the marine engine 60 contains a carbon dioxide CO2 concentration of 5 vol% or less.

[0028] Table 1 below shows examples of the composition and concentration of the methane-rich gas (referred to as "reformed gas" in Table 1) generated in the LPG reformer 40 before CO2 removal and the methane-rich gas processed in the CO2 separator 50 after CO2 removal.

[0029] [Table 1]

[0030] In the marine engine fuel supply system configured as described above, the methane-rich gas produced by the LPG reformer 40 (reformer) has a carbon dioxide (CO2) concentration of less than 20 vol% and a hydrogen (H2) concentration of 10 vol% or more. A portion of the carbon dioxide (CO2) contained in this methane-rich gas is removed by the CO2 separator 50 (removal device), reducing the carbon dioxide (CO2) concentration and increasing the concentrations of methane (CH4) and hydrogen (H2). This allows the methane-rich gas with increased concentrations of methane (CH4) and hydrogen (H2) to be supplied to the marine engine 60 as fuel during gas mode operation without using a hydrogen supply source such as a hydrogen storage tank. The CO2 separator 50 (removal device) is smaller than the hydrogen storage tank, allowing for effective use of the limited installation space within the ship.

[0031] Furthermore, the concentration of carbon dioxide CO2 contained in the methane-rich gas supplied to the marine engine 60 is reduced, so that the concentration of carbon dioxide CO2 in the exhaust gas can be reduced.

[0032] All of the carbon dioxide CO2 contained in the methane-rich gas produced in the LPG reformer 40 (reformer) may be removed by a removal device.

[0033] Furthermore, in the above-described marine engine fuel supply device, there is no need to supply LNG and hydrogen H2 from different nozzles to the intake port 61 of the marine engine 60 and mix them, and methane-rich gas can be supplied from a single gas injection valve 62 to the intake port 61 of the marine engine 60, thereby simplifying the engine structure.

[0034] Furthermore, in the marine engine fuel supply device, by setting the concentration of carbon dioxide CO2 in the methane-rich gas supplied from the CO2 separator 50 to the marine engine 60 to be 5 vol% or less, the concentration of hydrogen H2 contained in the methane-rich gas is further increased, and the combustion efficiency of the mixed combustion of methane CH4 and hydrogen H2 is improved when the marine engine 60 is operating in gas mode.

[0035] In addition, the CO2 separator 50 uses water vapor from the exhaust gas economizer 70 to remove carbon dioxide CO2 contained in the methane-rich gas, so the heat of the exhaust gas can be used to generate water vapor without the need for a separate water vapor generator, thereby reducing energy consumption for water vapor generation.

[0036] In the above embodiment, the marine engine fuel supply device is described as being mounted on an LPG carrier, but the marine engine fuel supply device of the present invention may be used on other ships.

[0037] Furthermore, in the above embodiment, a marine engine fuel supply system has been described that supplies fuel to marine engine 60, which is a dual fuel engine. However, the marine engine fuel supply system of the present invention may also be used for a lean-burn marine engine other than a dual fuel engine.

[0038] Although specific embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. [Explanation of symbols]

[0039] 10...LPG storage tank 20...Pump 30...Carburetor 40...LPG reformer (reformer) 50…CO2 separator (removal device) 60...Marine engine 61...Intake port 62...Gas injection valve 62a...Injection nozzle 63...Fuel injection valve 64...Cylinder 65...Piston 66...Combustion chamber 70...Exhaust gas economizer

Claims

1. a reformer that uses liquefied petroleum gas as a raw material to produce a methane-rich gas containing methane, hydrogen, and carbon dioxide; a removal device that removes part or all of the carbon dioxide contained in the methane-rich gas produced by the reformer and supplies the gas to a marine engine; Equipped with A fuel supply device for a marine engine, wherein the methane-rich gas produced in the reformer has a carbon dioxide concentration of less than 20 vol % and a hydrogen concentration of 10 vol % or more.

2. 2. The marine engine fuel supply system according to claim 1, A marine engine fuel supply system, wherein the methane-rich gas supplied from the removal device to the marine engine has a carbon dioxide concentration of 5 vol % or less.

3. 2. The marine engine fuel supply system according to claim 1, The removal device removes carbon dioxide contained in the methane-rich gas by utilizing water vapor from an exhaust gas economizer.

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