Heating furnace system

Abstract

This system uses carbon-containing fuel and provides a heating furnace system suitable for reducing CO2 emissions. [Solution] A heating furnace system comprising a heating furnace having a burner that heats an object to be heated by burning fuel with an oxidizer, and a CO2 recovery device that recovers CO2 from exhaust gas produced by the combustion of the fuel by the burner and discharged from the heating furnace, wherein the fuel includes a carbon-containing fuel and the oxidizer has an oxygen concentration of 90% or more.

Description

Technical Field

[0001] The present invention relates to a heating furnace system.

Background Art

[0002] There is known a burner that heats an object to be heated by burning fuel with an oxidizing agent (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a heating furnace system that heats an object to be heated by a burner as described above, when using a carbon-containing fuel such as fossil fuel as the fuel, the amount of CO2 emissions as a greenhouse gas becomes a problem.

[0005] Therefore, an object of the present invention is to provide a heating furnace system that uses a carbon-containing fuel as the fuel and is suitable for reducing CO2 emissions.

Means for Solving the Problems

[0006] One aspect of the present invention is as follows.

[0007] [1] A heating furnace having a burner that heats an object to be heated by burning fuel with an oxidizing agent, a CO2 recovery device that recovers CO2 from the exhaust gas generated by the combustion of the fuel by the burner and discharged from the heating furnace, and the fuel includes a carbon-containing fuel, the oxidizing agent has an oxygen concentration of 90% or more, a heating furnace system.

[0008] [2] The heating furnace system according to [1], further comprising a fuel regeneration unit that chemically transforms the CO2 recovered by the CO2 recovery device into a reusable fuel that is reused as part of the fuel.

[0009] [3] The heating furnace system according to [2], wherein the fuel regeneration unit chemically converts the CO2 recovered by the CO2 recovery device into CO as a recycled fuel by reacting it with hydrogen in a reverse shift reaction.

[0010] [4] The heating furnace system according to [2] or [3], wherein the fuel regeneration unit chemically transforms the CO2 recovered by the CO2 recovery device into CH4 as the recycled fuel by reacting it with hydrogen as a Sabatier reaction.

[0011] [5] The heating furnace system according to [3] or [4], wherein the fuel regeneration unit has a hydrogen generation unit that chemically transforms H2O into the hydrogen used in the fuel regeneration unit by electrolysis.

[0012] [6] The heating furnace system according to [5], wherein the fuel regeneration unit utilizes electricity generated from renewable energy for electrolysis in the hydrogen generation unit.

[0013] [7] The fuel regeneration unit is a heating furnace system according to any one of [2] to [6], wherein the CO2 recovered by the CO2 recovery device is chemically converted into CO as a reusable fuel by plasma and a catalyst.

[0014] [8] The heating furnace system according to [7], wherein the fuel regeneration unit utilizes electricity generated from renewable energy for the generation of the plasma.

[0015] [9] The fuel regeneration unit uses the electric power generated by renewable energy to regenerate the reusable fuel from the CO2, the heating furnace system according to any one of [2] to [8].

[0016]

[10] The fuel regeneration unit regenerates the reusable fuel within the range where the electric power generated by the renewable energy can be used, the heating furnace system according to [9].

[0017]

[11] It has a control device for controlling the usage amount of the fuel and the usage amount of the oxidant, The control device, A calculation unit that calculates the amount of the reusable fuel that can be regenerated in the fuel regeneration unit within the range where the electric power generated by the renewable energy can be used, Based on the calculation result by the calculation unit, it has a determination unit that determines the usage amount of the fuel and the usage amount of the oxidant, the heating furnace system according to

[10] .

Advantages of the Invention

[0018] According to the present invention, a heating furnace system suitable for reducing the CO2 emission amount can be provided by using a carbon-containing fuel as the fuel.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic diagram showing the heating furnace system of the first embodiment of the present invention. [Figure 2] It is a schematic diagram showing the heating furnace system of the second embodiment of the present invention. [Figure 3] It is a schematic diagram showing the heating furnace system of the third embodiment of the present invention.

Modes for Carrying Out the Invention

[0022] Fuel 2 is not particularly limited as long as it contains a carbon-containing fuel, but it is preferable that it contains a carbon-containing fuel as its main component (i.e., the carbon-containing fuel is more than 50% and 100% or less). In this embodiment, the carbon-containing fuel is mainly composed of methane (CH4), but is not limited to this, and may be various fossil fuels or mixtures thereof. As fossil fuels, solid fuels such as pulverized coal, liquid fuels such as kerosene or heavy oil, or gaseous fuels such as natural gas or LPG can be used.

[0023] It is preferable that fuel 2 is supplied to the burner 5a in a gaseous state (i.e., as fuel gas) and ejected from the burner 5a. Similarly, it is preferable that oxidizer 3 is supplied to the burner 5a in a gaseous state (i.e., as oxidizer gas) and ejected from the burner 5a. A portion of oxidizer 3 may be supplied to the burner flame 5b without passing through the burner 5a. It is preferable that this portion of oxidizer 3 is also supplied in a gaseous state.

[0024] The heating furnace 5 heats the object to be heated 4 by radiant heat transfer from the burner flame 5b produced by burning fuel 2 with the burner 5a, and by convective heat transfer from the flow of combustion gases generated by the combustion, and melts it as needed. The object to be heated 4 is not particularly limited and may be, for example, a metal such as aluminum or glass.

[0025] The exhaust gas 6 contains CO2 and H2O (water) produced by combustion, as well as other gases (for example, N2: nitrogen contained in the oxidizer 3). The CO2 recovery device 7 recovers CO2 from the exhaust gas 6 and discharges H2O and other gases. The type of CO2 recovery device 7 is not particularly limited and can be appropriately selected depending on the amount of exhaust gas discharged from the heating furnace 5. Examples include membrane separation, PSA (Pressure Swing Adsorption), chemical adsorption, or physical adsorption.

[0026] The chemical formulas for burning CH4, the main component of common fossil fuels, in air and in oxygen are as follows. Table 1 shows the CO2 and H2O concentrations in the exhaust gas 6 for each case. CH4+2O2+8N2→CO2+2H2O+8N2...Formula (1) CH4+2O2 →CO2+2H2O ...Equation (2) Equation (1) shows the case when CH4 is burned in air. Equation (2) shows the case when CH4 is burned in oxygen.

[0027] [Table 1]

[0028] As shown in Table 1, the CO2 concentration in the combustion gas is higher when combustion is performed using oxygen (oxygen concentration 100%) than when combustion is performed using air (oxygen concentration 20%). Therefore, as in this embodiment, by using an oxidizer 3 with an oxygen concentration of 90% or higher, the CO2 concentration in the exhaust gas 6 (combustion gas discharged from the heating furnace 5) can be increased, making it easier to recover CO2 with the CO2 recovery device 7. In addition, the proportion of radiant gases (CO2 and H2O) in the combustion gas increases, which improves the radiant heat transfer efficiency. Furthermore, the energy efficiency for heating can be improved by improving the radiant heat transfer efficiency and reducing the amount of exhaust gas 6.

[0029] The heating furnace system 1 has a fuel regeneration unit 8 that chemically transforms the CO2 recovered by the CO2 recovery device 7 into recycled fuel 2a, which is reused as part of the fuel 2. With this configuration, by circulating the recovered CO2 as recycled fuel 2a, the amount of CO2 emitted from the heating furnace system 1 to the outside can be reduced, and at the same time, the amount of fuel 2 consumed can be reduced.

[0030] The fuel regeneration unit 8 has a reverse shift reaction unit 8a that chemically transforms the CO2 recovered by the CO2 recovery device 7 into CO as a reusable fuel 2a by reacting it with hydrogen in a reverse shift reaction.

[0031] The reverse shift reaction is the reverse reaction (reaction from the right side to the left side) of the water-gas shift reaction shown in equation (3) below. It is a reaction in which hydrogen (H2) is added to CO2 and reacted with a catalyst to chemically change it into CO and H2O. CO+H2O→CO2+H2+41.2[kJ / mol]...Equation (3)

[0032] The fuel regeneration unit 8 utilizes electricity generated from renewable energy sources to regenerate the recycled fuel 2a from CO2. The fuel regeneration unit 8 has a hydrogen generation unit 8b that chemically transforms H2O into hydrogen used in the fuel regeneration unit 8 (in this embodiment, the reverse shift reaction unit 8a) by electrolysis. In this embodiment, it is preferable that the hydrogen generation unit 8b uses H2O discharged from the CO2 recovery device 7 and H2O produced in the reverse shift reaction unit 8a as the H2O to be electrolyzed. In this embodiment, it is preferable that the oxygen generated when H2O is electrolyzed by the hydrogen generation unit 8b be reused as part of the oxidizing agent 3.

[0033] The fuel regeneration unit 8 utilizes electricity generated from renewable energy sources for electrolysis in the hydrogen production unit 8b. In this embodiment, electricity generated from renewable energy sources is acquired and utilized by the acquisition unit 9. Renewable energy sources are non-fossil energy sources that can be used sustainably as energy sources, such as solar, wind, hydro, geothermal, solar thermal, or biomass.

[0034] The hydrogen used in the fuel regeneration unit 8 (reverse shift reaction unit 8a) is not limited to that produced in the hydrogen generation unit 8b, but may be supplied from any source. However, in this case, it is preferable that the hydrogen supplied from the source be so-called clean hydrogen, in which the amount of greenhouse gas (CO2) emitted in its production process is 3.4 kgCO2e / kgH2 or less.

[0035] The fuel regeneration unit 8 regenerates the recycled fuel 2a within the range of electricity generated from renewable energy (within the range of electricity acquired by the acquisition unit 9). With the above configuration, greenhouse gases emitted during the regeneration process of recycled fuel 2a can be reduced.

[0036] The heating furnace system 1 has a control device 10 that controls the amount of fuel 2 used and the amount of oxidizer 3 used. The control device 10 includes a calculation unit 10a that calculates the amount of reusable fuel 2a that can be recycled in the fuel recycling unit 8 within the range where electricity generated from renewable energy can be used, and a determination unit 10b that determines the amount of fuel 2 used and the amount of oxidizer 3 used based on the calculation results from the calculation unit 10a (as well as operating conditions such as the temperature of the heating furnace 5 and the amount of material to be heated 4). With the above configuration, even if the amount of electricity obtained from renewable energy is unstable, the heating furnace 5 can be operated stably without affecting the production volume or quality of the material to be heated 4.

[0037] The fuel regeneration unit 8 is not limited to a configuration having a reverse shift reaction unit 8a that chemically converts CO2 recovered by the CO2 recovery device 7 into CO as reusable fuel 2a by a reverse shift reaction, as in this embodiment. For example, instead of the reverse shift reaction unit 8a, the fuel regeneration unit 8 may have a Sabatier reaction unit 8c, as in the second embodiment shown in Figure 2, which chemically converts CO2 recovered by the CO2 recovery device 7 into CH4 as reusable fuel 2a by reacting it with hydrogen as a Sabatier reaction. The hydrogen used in the Sabatier reaction unit 8c is the same as in the first embodiment.

[0038] The Sabatier reaction is a reaction in which hydrogen and carbon dioxide are placed under high temperature and high pressure, and methane and water are produced using a catalyst, as shown in equation (4) below. It is preferable that the H2O produced in the Sabatier reaction is used as the H2O to be electrolyzed in the hydrogen production unit 8b, as in the first embodiment. CO2+4H2→CH4+2H2O...Formula (4)

[0039] Furthermore, instead of having a reverse shift reaction unit 8a or a Sabatier reaction unit 8c, the fuel regeneration unit 8 may be configured, as in the third embodiment shown in Figure 3, to chemically convert the CO2 recovered by the CO2 recovery device 7 into CO as recycled fuel 2a using plasma and a catalyst.

[0040] In this embodiment, the fuel regeneration unit 8 (plasma processing unit 8d) utilizes electricity generated from renewable energy sources to generate plasma. This electricity is acquired by the acquisition unit 9, as in the first embodiment.

[0041] The fuel regeneration unit 8 may have any combination of the reverse shift reaction unit 8a, the Sabatier reaction unit 8c, and the plasma processing unit 8d.

[0042] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and the embodiments described above can be modified in various ways without departing from the spirit of the present invention. [Explanation of symbols]

[0043] 1. Heating Furnace System 2 fuel 2a Recycled fuel 3. Oxidizing agent 4 Object to be heated 5 Heating furnace 5a Burner 5b Burner Flame 6. Exhaust gas 7 CO2 recovery device 8 Fuel regeneration section 8a Reverse shift reaction section 8b Hydrogen generation section 8c Sabatier reaction section 8d Plasma Processing Unit 9 Acquisition Department 10 Control device 10a Calculation Unit 10b Decision section

Claims

1. A heating furnace having a burner that heats an object to be heated by burning fuel with an oxidizer, CO2 is produced by the combustion of the fuel by the burner and emitted from the furnace. ２ CO2 recovery ２ It has a recovery device, The fuel mentioned above includes carbon-containing fuel. The oxidizing agent is a heating furnace system in which the oxygen concentration is 90% or higher.

2. The aforementioned CO ２ CO2 recovered by the recovery device ２ The heating furnace system according to claim 1, further comprising a fuel regeneration unit that chemically transforms the fuel into a reusable fuel that is reused as part of the aforementioned fuel.

3. The fuel regeneration unit is the CO ２ CO2 recovered by the recovery device ２ The heating furnace system according to claim 2, wherein the material is chemically converted into CO as a recycled fuel by reacting it with hydrogen as a reverse shift reaction.

4. The fuel regeneration unit is the CO ２ recovered by the recovery device, and CO ２ is reacted with hydrogen as a Sabatier reaction to chemically change it into CH as the reuse fuel. ４ The heating furnace system according to claim 2.

5. The fuel regeneration unit is H ２ A heating furnace system according to claim 3 or 4, further comprising a hydrogen generation unit that chemically transforms oxygen into the hydrogen used in the fuel regeneration unit by electrolysis.

6. The heating furnace system according to claim 5, wherein the fuel regeneration unit utilizes electricity generated from renewable energy for electrolysis in the hydrogen generation unit.

7. The fuel regeneration unit is the CO ２ CO2 recovered by the recovery device ２ The heating furnace system according to claim 2, wherein the material is chemically converted into CO as the recycled fuel by plasma and a catalyst.

8. The heating furnace system according to claim 7, wherein the fuel regeneration unit utilizes electricity generated from renewable energy for the generation of the plasma.

9. The fuel regeneration unit is the CO ２ The heating furnace system according to claim 2, wherein electricity generated from renewable energy is used to regenerate the recycled fuel.

10. The heating furnace system according to claim 9, wherein the fuel regeneration unit regenerates the recycled fuel within the range in which electricity generated from the renewable energy can be used.

11. The system includes a control device that controls the amount of fuel used and the amount of oxidizer used. The control device is A calculation unit that calculates the amount of recycled fuel that can be recycled in the fuel recycling unit within the range in which electricity generated from the aforementioned renewable energy can be used, The heating furnace system according to claim 10, further comprising a determination unit that determines the amount of fuel used and the amount of oxidizer used based on the calculation results of a calculation unit.

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