Gasifier

Abstract

To reduce greenhouse gas emissions in the generation of fuel.SOLUTION: A gasifier 1 comprises a mixer 4 that produces a mixture of liquid biofuel and hydrogen gas, and a reactor 5 containing a catalyst that produces methane gas from the mixture at reaction temperature.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed herein relates to a gasifier. [Background technology]

[0002] In the technical field related to gasification apparatuses, a gasification apparatus such as that disclosed in Patent Document 1 is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2011-510115 Summary of the Invention [Problem to be solved by the invention]

[0004] From the viewpoint of preventing global warming, it is desirable to reduce greenhouse gas emissions. For example, there is a demand for technology that can reduce greenhouse gas emissions in the generation of fuel for boilers.

[0005] The technology disclosed in this specification aims to reduce greenhouse gas emissions in the production of fuels. [Means for solving the problem]

[0006] The present specification discloses a gasifier that includes a mixer that produces a mixture of liquid biofuel and hydrogen gas, and a reactor containing a catalyst that produces methane gas from the mixture at a reaction temperature. [Effects of the Invention]

[0007] The technology disclosed in this specification makes it possible to reduce greenhouse gas emissions in the production of fuel. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically illustrating a gasification apparatus according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments.

[0010] 1 is a diagram schematically illustrating a gasification apparatus 1 according to an embodiment. The gasification apparatus 1 gasifies liquid biofuel using hydrogen gas to produce methane gas. The methane gas produced in the gasification apparatus 1 is used as fuel for a boiler, for example.

[0011] As shown in FIG. 1, the gasification apparatus 1 includes a fuel tank 2, a hydrogen tank 3, a mixer 4, a reactor 5, a heat exchanger 9, a condensate tank 10, a pump 11, a hydrogen sensor 12, a regulator 13, and a controller 14.

[0012] The fuel tank 2 contains liquid biofuel. Examples of liquid biofuel include fatty acid methyl ester, biomethanol, and bioethanol. Fatty acid methyl ester (FAME) is produced by methyl esterifying vegetable oil, waste cooking oil, etc. Biomethanol is produced by partially burning and cooling biomass materials such as plants. Bioethanol is produced by fermenting and distilling biomass materials such as sugarcane or corn. The liquid biofuel contained in the fuel tank 2 is supplied to the mixer 4 via a fuel supply line 15.

[0013] The hydrogen tank 3 contains hydrogen gas. The hydrogen gas is green hydrogen produced using renewable energy. The hydrogen gas contained in the hydrogen tank 3 is supplied to the mixer 4 via a hydrogen supply line 16.

[0014] The mixer 4 produces a mixture of liquid biofuel and hydrogen gas. The mixer 4 mixes the liquid biofuel supplied from the fuel tank 2 with the hydrogen gas supplied from the hydrogen tank 3. An example of the mixer 4 is an ejector that mixes the liquid biofuel and hydrogen gas by injecting hydrogen gas into the liquid biofuel. The mixture of liquid biofuel and hydrogen gas produced in the mixer 4 is supplied to the reactor 5 via a mixture line 17.

[0015] Reactor 5 includes a reaction vessel that accommodates the mixture, a catalyst that produces methane gas from the mixture at a reaction temperature, and a heater that heats the reaction vessel to the reaction temperature. Examples of catalysts include zeolite, silicon dioxide (SiO2), and aluminum oxide (Al2O3). The reaction temperature is, for example, 250°C or higher and 600°C or lower. When the mixture of liquid biofuel and hydrogen gas is heated to the reaction temperature and comes into contact with the catalyst, methane gas is produced from the mixture through a catalytic reaction. The product, including methane gas, produced in reactor 5 is supplied to heat exchanger 9 via product line 18.

[0016] Heat exchanger 9 exchanges heat between the product, including methane gas, produced in reactor 5 and a refrigerant. Water vapor may be produced in reactor 5 along with methane gas. Furthermore, the product may contain liquid biofuel vapor that remains after not completely reacting in reactor 5. That is, the product produced in reactor 5 may contain not only methane gas but also water vapor and liquid biofuel vapor. Heat exchanger 9 separates the water vapor and liquid biofuel vapor from the methane gas. By cooling the product with a refrigerant in heat exchanger 9, the water vapor and liquid biofuel vapor are condensed and separated from the methane gas.

[0017] The methane gas from which water vapor and liquid biofuel vapor have been separated in the heat exchanger 9 is sent to a gas line 19. The methane gas sent out from the heat exchanger 9 flows through the gas line 19. The methane gas that has flowed through the gas line 19 is used as fuel for the boiler. Note that the hydrogen gas that remains without being completely reacted in the reactor 5 is also sent out from the heat exchanger 9 to the gas line 19 together with the methane gas.

[0018] The hydrogen sensor 12 detects hydrogen gas flowing through the gas line 19. The hydrogen sensor 12 detects the concentration of hydrogen gas relative to methane gas. The hydrogen sensor 12 may also detect the flow rate of hydrogen gas flowing through the gas line 19. The detection data from the gas line 19 is sent to the controller 14.

[0019] The regulator 13 adjusts the amount of hydrogen gas supplied from the hydrogen tank 3 to the mixer 4. An example of the regulator 13 is a flow rate control valve. The regulator 13 is disposed on the hydrogen supply line 16. The controller 14 outputs a control command to the regulator 13 to adjust the amount of hydrogen gas supplied from the hydrogen tank 3 to the mixer 4 based on the detection data of the hydrogen sensor 12. The controller 14 outputs a control command to the regulator 13 to adjust the amount of hydrogen gas so that hydrogen gas is detected by the hydrogen sensor 12. The controller 14 controls the regulator 13 so that the concentration of hydrogen gas detected by the hydrogen sensor 12 becomes a target value. In this embodiment, the target value is a value slightly higher than zero. The target value of the hydrogen gas concentration is, for example, 1% or more and 5% or less.

[0020] If the hydrogen gas concentration detected by the hydrogen sensor 12 is a high value exceeding 5%, this means that too much hydrogen gas is being supplied from the hydrogen tank 3 to the mixer 4, and a large amount of hydrogen gas remains without fully reacting in the reactor 5. If the hydrogen gas concentration detected by the hydrogen sensor 12 is a low value below 1%, this means that too little hydrogen gas is being supplied from the hydrogen tank 3 to the mixer 4, and there is a high possibility that a large amount of liquid biofuel will remain without fully reacting in the reactor 5. The controller 14 adjusts the amount of hydrogen gas supplied from the hydrogen tank 3 to the mixer 4 so that too much hydrogen gas is not supplied from the hydrogen tank 3 to the mixer 4, and so that the liquid biofuel can sufficiently react in the reactor 5.

[0021] As described above, the water vapor and liquid biofuel vapor are condensed in the heat exchanger 9. The water vapor is condensed to produce water. The liquid biofuel vapor is condensed back into liquid biofuel. The condensate, which includes water and liquid biofuel, is discharged from the heat exchanger 9 to the condensate tank 10 via the condensate line 20.

[0022] The pump 11 operates to return the liquid biofuel produced by condensation to the mixer 4. The liquid biofuel has a lower specific gravity than water. In the condensate tank 10, the liquid biofuel accumulates above the water. The top of the condensate tank 10 is connected to the fuel supply line 15 via a return line 21. The pump 11 is disposed in the return line 21. The pump 11 operates to supply the liquid biofuel accumulated at the top of the condensate tank 10 to the mixer 4 via the fuel supply line 15.

[0023] As described above, the gasification apparatus 1 according to the embodiment includes a mixer 4 that produces a mixture of liquid biofuel and hydrogen gas, and a reactor 5 that contains a catalyst that produces methane gas from the mixture at a reaction temperature. Methane gas, which serves as fuel for the boiler, is produced from the liquid biofuel. Gas fuel is produced from the liquid biofuel, reducing greenhouse gas emissions during boiler operation.

[0024] For example, when fatty acid methyl esters are used as fuel, soot may be generated during combustion of the fatty acid methyl esters. When biomethanol or bioethanol is used as fuel, the required amount of heat may not be obtained. By using methane gas as fuel, soot generation is suppressed and the required amount of heat can be obtained.

[0025] Additionally, the transportation costs of liquid biofuels can be high. According to embodiments, the liquid biofuel is gasified into methane gas. The transportation costs of methane gas are likely to be lower than the transportation costs of liquid biofuels. Furthermore, methane gas can be transported using existing gas pipelines (infrastructure).

[0026] The gasification apparatus 1 includes a heat exchanger 9 that exchanges heat between a product containing methane gas produced in the reactor 5 and a refrigerant. Even if the methane gas produced in the reactor 5 contains water vapor and liquid biofuel vapor, the water vapor and liquid biofuel vapor are separated from the methane gas in the heat exchanger 9.

[0027] In the heat exchanger 9, the liquid biofuel vapor is condensed and returned to liquid biofuel. The gasifier 1 is equipped with a pump 11 that returns the liquid biofuel produced by condensation to the mixer 4. The liquid biofuel returned to the mixer 4 is mixed with hydrogen gas and then supplied to the reactor 5. This ensures that the liquid biofuel is used without waste.

[0028] The gasification apparatus 1 includes a gas line 19 through which the methane gas sent from the heat exchanger 9 flows, a hydrogen sensor 12 that detects the hydrogen gas flowing through the gas line 19, and a regulator 13 that adjusts the amount of hydrogen gas supplied to the mixer 4 based on the detection data of the hydrogen sensor 12. The regulator 13 ensures that an appropriate amount of hydrogen gas is supplied from the hydrogen tank 3 to the mixer 4.

[0029] The regulator 13 adjusts the amount of hydrogen gas so that hydrogen gas can be detected by the hydrogen sensor 12. As a result, an appropriate amount of hydrogen gas is supplied from the hydrogen tank 3 to the mixer 4 so that an excessive amount of hydrogen gas is not supplied from the hydrogen tank 3 to the mixer 4 and so that the liquid biofuel can react sufficiently in the reactor 5.

[0030] In the above-described embodiment, the methane gas generated by the gasification apparatus 1 does not have to be used as fuel for the boiler, and may be used as fuel for a combustion appliance other than the boiler. Also, the methane gas does not have to be used as fuel. [Explanation of symbols]

[0031] 1...gasifier, 2...fuel tank, 3...hydrogen tank, 4...mixer, 5...reactor, 9...heat exchanger, 10...condensate tank, 11...pump, 12...hydrogen sensor, 13...regulator, 14...controller, 15...fuel supply line, 16...hydrogen supply line, 17...mixture line, 18...product line, 19...gas line, 20...condensate line, 21...return line

Claims

1. a mixer that generates a mixture of liquid biofuel and hydrogen gas; a reactor containing a catalyst that produces methane gas from the mixture at a reaction temperature. Gasifier.

2. a heat exchanger that exchanges heat between the methane gas-containing product produced in the reactor and a refrigerant; The gasifier of claim 1 .

3. In the heat exchanger, the liquid biofuel vapor is condensed; a pump for returning the liquid biofuel produced by the condensation to the mixer; The gasifier of claim 2 .

4. a gas line through which the methane gas delivered from the heat exchanger flows; a hydrogen sensor for detecting hydrogen gas flowing through the gas line; and an adjuster that adjusts the amount of hydrogen gas supplied to the mixer based on the detection data of the hydrogen sensor. The gasifier of claim 2 .

5. the regulator adjusts the amount of the hydrogen gas so that the hydrogen gas is detected by the hydrogen sensor. The gasifier of claim 4.

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