Method and system for generating power

Abstract

To generate power using magnesium as a fuel.SOLUTION: A method for generating power includes: a melting step 12 (liquefying step) of melting (liquefying) magnesium 21; a spraying step 13 of spraying the magnesium (mixed liquid 23) that is melt (liquefied) in the melting step 12 (liquefying step); a combustion step 14 (oxidation step) of combusting (oxidizing) the magnesium (misty mixture 25) that is sprayed in the spraying step 13 and generating a magnesium oxide 27; and a power generation step 15 of generating power using reaction heat 29 that is generated in the combustion step 14.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for generating electricity using magnesium as fuel. [Background technology]

[0002] Patent Document 1 discloses an external combustion engine that uses magnesium as fuel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 55-35188 Summary of the Invention [Problem to be solved by the invention]

[0004] When a large block of magnesium is burned, a layer of magnesium oxide forms on the surface of the magnesium that is exposed to air, blocking the air and hindering the combustion of the magnesium inside, slowing down the burning speed and leaving unburned residue. Magnesium oxide also acts as an insulator, reducing the amount of heat that can be extracted. One way to prevent this is to process magnesium into a powder, but this creates the risk of spontaneous combustion and makes it difficult to handle. The present invention aims to solve such problems, for example. [Means for solving the problem]

[0005] The power generation method includes a liquefaction process for liquefying magnesium, a spraying process for spraying the magnesium liquefied in the liquefaction process, an oxidation process for oxidizing the magnesium sprayed in the spraying process to produce magnesium oxide, and a power generation process for generating electricity by utilizing reaction heat generated in the oxidation process. The power generation system includes a liquefaction device that liquefies magnesium, a spraying device that sprays the magnesium liquefied by the liquefaction device, an oxidation device that oxidizes the magnesium sprayed by the spraying device to produce magnesium oxide, and a power generation device that generates electricity by utilizing reaction heat generated in the oxidization device. Effect of the Invention

[0006] According to the power generation method and power generation system, magnesium is liquefied, for example by heating it to a temperature equal to or higher than its melting point, and then sprayed and combusted, so that it is possible to prevent a decrease in the combustion rate and the generation of unburned remains. [Brief description of the drawings]

[0007] [Figure 1] FIG. [Diagram 2] FIG. 1 is a diagram showing an example of a power generation system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] With reference to FIG. 1, a power generation process 10 will be described. The power generation process 10 includes, for example, a melting step 12, an atomization step 13, a combustion step 14, power generation steps 15 and 16, and a magnesium reduction step 17.

[0009] In the melting step 12 (an example of a liquefying step), the magnesium 21 is liquefied. For example, the magnesium 21 and the tin 22 are mixed by being poured into a melting tank, and the mixed magnesium 21 and tin 22 are heated to a temperature equal to or higher than the melting point to melt the magnesium 21 and the tin 22, thereby liquefying the magnesium 21 and the tin 22 and generating a mixed liquid 23 of the magnesium 21 and the tin 22.

[0010] In the spraying process 13, the magnesium 21 liquefied in the melting process 12 is sprayed. For example, the mixed liquid 23 generated in the melting process 12 is sprayed into the combustion furnace by a spray nozzle or the like provided in the combustion furnace to generate a mist mixture 25. In the spraying process 13 (an example of a water spraying process), water 24 (steam) is sprayed and mixed with the sprayed magnesium 21. For example, the water 24 is sprayed into the combustion furnace by an injection nozzle or the like provided in the combustion furnace. The injection nozzle for spraying the water 24 may be the injection nozzle for injecting the mixed liquid 23, or may be an injection nozzle different from the injection nozzle for injecting the mixed liquid 23. For example, the liquefied magnesium 21 is atomized by spraying water 24 or ejecting steam gas. That is, the liquefied magnesium is blown away to create fine particles of magnesium, and a mist mixture 25 in which the water 24 and magnesium 21 are mixed is generated.

[0011] In the combustion step 14 (an example of an oxidation step), the magnesium 21 sprayed in the spray step 13 is oxidized to produce magnesium oxide 27. For example, the magnesium 21 contained in the mist mixture 25 is combusted by introducing air (oxygen 26) into a combustion furnace in which the mist mixture 25 is suspended. This reaction generates reaction heat 29.

[0012] In addition, in the combustion process 14 (an example of a reduction process), the water 24 sprayed in the spraying process 13 is reduced by the magnesium 21 sprayed in the spraying process 13 to generate hydrogen. For example, the magnesium 21 and water 24 contained in the mist mixture 25 generated in the spraying process 13 react with each other to generate magnesium oxide 27 and hydrogen 28. This reaction also generates reaction heat 29.

[0013] Furthermore, in the combustion step 14 (an example of a tin oxidation step), the tin 22 sprayed in the spray step 13 is oxidized to generate tin oxide. For example, the tin 22 contained in the mist mixture 25 is burned together with the magnesium 21 by the oxygen 26 mixed into the mist mixture 25 in order to burn the magnesium 21. This reaction also generates reaction heat 29. Then, in the combustion process 14 (an example of a tin reduction process), some of the hydrogen 28 produced by reducing the water 24 with the magnesium 21 reduces the tin oxide produced by oxidizing the tin 22 to produce tin 22. This reaction also generates reaction heat 29. The produced tin 22 may be reused in the melting process 12.

[0014] In the power generation process 15, electricity is generated by utilizing the reaction heat 29 generated in the combustion process 14. For example, electricity is generated by boiling water to generate steam, which then rotates a turbine.

[0015] In the power generation process 16 (an example of a hydrogen power generation process), hydrogen 28 generated in the combustion process 14 is used to generate electricity. For example, hydrogen 28 is combusted in a combustion furnace separate from the combustion furnace, and the generated reaction heat is used to generate electricity. Alternatively, electricity may be generated using a hydrogen gas turbine.

[0016] In the magnesium reduction step 17 (an example of a reduction step), the magnesium oxide 27 produced in the combustion step 14 is reduced to produce magnesium 21. The produced magnesium 21 may be reused in the melting step 12.

[0017] The power generation system 30 will be described with reference to FIG. The power generation system 30 generates power by executing the power generation process 10. The power generation system 30 includes, for example, a magnesium production apparatus 31, a magnesium melting apparatus 32, a magnesium combustion apparatus 33, a power generation apparatus 34, and a hydrogen power generation apparatus 35.

[0018] The magnesium manufacturing apparatus 31 (an example of a magnesium reduction apparatus) manufactures magnesium by carrying out the magnesium reduction step 17. In the magnesium manufacturing apparatus 31, for example, a magnesium-tin alloy connected to the cathode of a DC power supply and zirconium dioxide (zirconia) connected to the anode of the DC power supply are placed in a heat-resistant container. When magnesium oxide molten salt containing magnesium oxide as a raw material is placed in the heat-resistant container and the heat-resistant container is heated to, for example, 1300°C, the magnesium oxide molten salt is electrolyzed and magnesium is precipitated on the magnesium-tin alloy connected to the cathode. This is collected and the tin and magnesium are separated to obtain magnesium.

[0019] The magnesium manufacturing apparatus 31 is installed, for example, near a large-scale power generation facility. This makes it possible to reduce transmission losses. The magnesium manufacturing apparatus 31 manufactures magnesium by using, for example, surplus electricity from a large-scale power generation facility whose output is difficult to adjust, or electricity from a solar power generation facility whose output is unstable. Energy can be stored in the form of magnesium.

[0020] The magnesium melting apparatus 32 (an example of a liquefaction apparatus) melts magnesium by carrying out the melting step 12. For example, solid magnesium and solid or liquid tin are charged into a melting tank heated to 200°C to 850°C, thereby melting the magnesium and tin to obtain a mixed liquid of magnesium and tin. It is possible to melt only magnesium without adding tin, but adding tin is preferable because it allows magnesium to be melted at a temperature lower than the melting point of magnesium, which is 650°C, thereby reducing energy consumption.

[0021] The magnesium melting apparatus 32 is installed, for example, near the power consumption area, which can reduce transmission losses. Magnesium produced in magnesium production equipment 31 is transported to magnesium melting equipment 32 by transportation means such as trucks. That is, solid magnesium is transported instead of transmitting electricity using power lines. Since the energy required to transport solid magnesium is smaller than the energy lost in transmitting electricity, energy loss can be suppressed.

[0022] The magnesium combustion device 33 (an example of an injection device and an oxidation device) combusts magnesium by carrying out the spraying step 13 and the combustion step 14. For example, the mixed liquid melted in the magnesium melting device 32 and steam are sprayed into a combustion furnace by an injection nozzle and mixed with air, thereby combusting magnesium and tin. The magnesium combustion device 33 is installed, for example, in the immediate vicinity of the magnesium melting device 32. The melting tank of the magnesium melting device 32 and the injection nozzle of the magnesium combustion device 33 are connected, for example, by a pipe. The mixed liquid melted in the magnesium melting device 32 is supplied to the magnesium combustion device 33 through the pipe by a pump installed in the middle of the pipe.

[0023] Tin oxide produced by combustion is reduced by hydrogen generated by the reduction of water by magnesium, returning to tin, which accumulates at the bottom of the combustion furnace. This is collected and reused in the magnesium melting device 32. For example, a second pipe is connected between the magnesium melting device 32 and the melting furnace of the magnesium combustion device 33, and the liquid tin that has accumulated at the bottom of the melting furnace is supplied to the melting tank of the magnesium melting device 32 via the second pipe by a pump installed in the middle of the second pipe.

[0024] Magnesium oxide produced by combustion also accumulates at the bottom of the combustion furnace as combustion ash. This is collected and reused in the magnesium production apparatus 31. For example, it is transported to the magnesium production apparatus 31 by a transportation means such as a truck. The energy required to transport magnesium from the magnesium production apparatus 31 to the magnesium melting apparatus 32 and the energy required to transport magnesium oxide from the magnesium melting apparatus 32 to the magnesium production apparatus 31 are combined to be smaller than the energy loss when transmitting electricity over the same distance using a power line, so energy loss can be reduced.

[0025] The power generation device 34 generates power by executing the power generation step 15. The power generation device 34 generates power, for example, by boiling water using reaction heat generated in the magnesium combustion device 33 to rotate a turbine. The power generation device 34 is installed, for example, in close proximity to the magnesium combustion device 33.

[0026] The hydrogen power generation device 35 generates electricity by executing the power generation process 16, using the hydrogen generated in the magnesium combustion device 33. For example, the hydrogen power generation device 35 introduces the hydrogen generated in the magnesium combustion device 33 and air into a re-burning furnace, burns the hydrogen, and boils water with the generated reaction heat to turn a turbine, thereby generating electricity. The hydrogen power generation device 35 is installed, for example, in close proximity to the magnesium combustion device 33. The re-burning furnace of the hydrogen power generation device 35 is installed, for example, at a higher position than the combustion furnace of the magnesium combustion device 33, and a pipe is used to connect the top of the combustion furnace of the magnesium combustion device 33 to the re-burning furnace of the hydrogen power generation device 35. This allows the hydrogen generated in the combustion furnace of the magnesium combustion device 33 to rise and be introduced into the re-burning furnace of the hydrogen power generation device 35.

[0027] The magnesium melting device 32, magnesium combustion device 33, power generation device 34 and hydrogen power generation device 35 can be configured on a relatively small scale and do not produce harmful substances, so as mentioned above, they can be placed in the immediate vicinity of the electricity consumption area, thereby reducing transmission losses.

[0028] The reaction heat generated in the magnesium combustion device 33 can be easily adjusted by adjusting the pressure of the pump or the opening of the valve that supplies the mixed liquid from the magnesium melting device 32 to the magnesium combustion device 33. Therefore, it is possible to generate only the necessary amount of electricity according to the power demand and the amount of power generated by other power generation facilities such as natural energy power generation.

[0029] The reaction heat generated when reducing water with magnesium is smaller than when magnesium is directly burned. Therefore, when some or all of the magnesium supplied to the combustion furnace is reacted with water vapor, the temperature inside the combustion furnace can be lowered compared to when all of the magnesium is burned. This reduces damage to the combustion furnace, extends its life, and allows the use of a combustion furnace with a relatively low heat resistance. In addition, the amount of electricity generated can be easily adjusted by changing the ratio of magnesium and water sprayed into the combustion furnace.

[0030] The above-described embodiment is an example for facilitating understanding of the present invention. The present invention is not limited thereto, and includes various modifications, changes, additions, or deletions without departing from the scope defined by the appended claims. This can be easily understood by those skilled in the art from the above description. [Explanation of symbols]

[0031] 10 power generation process, 12 melting process, 13 spray process, 14 combustion process, 15,16 power generation process, 17 magnesium reduction process, 21 magnesium, 22 tin, 23 mixed liquid, 24 water, 25 mist mixture, 26 oxygen, 27 magnesium oxide, 28 hydrogen, 29 reaction heat, 30 power generation system, 31 magnesium production equipment, 32 magnesium melting equipment, 33 magnesium combustion equipment, 34 power generation equipment, 35 hydrogen power generation equipment.

Claims

1. a liquefaction step of liquefying magnesium; a spraying step of spraying the magnesium liquefied in the liquefaction step; an oxidation step of oxidizing the magnesium sprayed in the spraying step to produce magnesium oxide; a power generation step of generating power by utilizing reaction heat generated in the oxidation step; A power generation method comprising:

2. a water spraying step of spraying water and mixing it with the magnesium sprayed in the spraying step; a reduction step of reducing the water sprayed in the water spraying step with the magnesium sprayed in the spraying step to generate hydrogen; The method of generating electricity according to claim 1 , further comprising:

3. A hydrogen power generation step of generating electricity using the hydrogen produced in the reduction step. The method of generating electricity according to claim 2 , further comprising:

4. In the liquefying step, magnesium and tin are mixed, and the mixed magnesium and tin are heated and melted to liquefy the magnesium and tin. The power generation method according to any one of claims 1 to 3.

5. In the liquefying step, magnesium and tin are mixed, and the mixed magnesium and tin are heated and melted to liquefy the magnesium and tin; In the spraying step, the mixed liquid of the magnesium and the tin liquefied in the liquefying step is sprayed, Furthermore, a tin oxidation step of oxidizing the tin sprayed in the spraying step to produce tin oxide; a tin reduction step of reducing the tin oxide produced in the tin oxidation step with the hydrogen produced in the reduction step to produce tin; The power generation method according to claim 2 or 3, comprising:

6. The tin produced in the tin reduction step is used in the liquefaction step. The power generation method according to claim 5.

7. A magnesium reduction step of reducing the magnesium oxide produced in the oxidation step to produce magnesium. Further comprising: The magnesium produced in the magnesium reduction step is used in the liquefaction step. The power generation method according to any one of claims 1 to 3.

8. A liquefaction device for liquefying magnesium; a spraying device that sprays the magnesium liquefied by the liquefaction device; an oxidation device for oxidizing the magnesium sprayed by the spray device to generate magnesium oxide; a power generation device that generates electricity by utilizing reaction heat generated in the oxidation device; A power generation system comprising:

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