Calcium oxide production method and apparatus

Abstract

The present invention provides a method and apparatus for producing calcium oxide that can be fired at a lower temperature than conventional methods. [Solution] A calcium oxide generating apparatus for generating calcium oxide from calcium carbonate, comprising a pressure vessel for chemically reacting the raw materials, a heating means, and a carbon dioxide detection means for detecting carbon dioxide in the pressure vessel, wherein the pressure vessel is composed of a firing chamber, a heating chamber, a mesh plate separating the firing chamber and the heating chamber, and an adjustment valve for adjusting the pressure in the pressure vessel, wherein calcium carbonate and iron as a catalyst are introduced into the firing chamber, water is introduced into the heating chamber, the water in the heating chamber is heated by the heating means to vaporize it into superheated steam, the superheated steam in the heating chamber is allowed to flow into the firing chamber through the mesh plate, calcium oxide and carbon dioxide are generated from the calcium carbonate in the firing chamber under high temperature and high pressure conditions, and the generation state of calcium oxide is confirmed by detecting the carbon dioxide in the pressure vessel with the carbon dioxide detection means.

Description

Technical Field

[0001] The present invention relates to a method for producing calcium oxide and a production apparatus, and more particularly to a method for producing calcium oxide and a production apparatus for performing firing at a lower temperature than conventional ones.

Background Art

[0002] Conventionally, quicklime (calcium oxide) has been widely used in various industries such as mortar used in construction and pH adjusters for acidic soil. In the process of producing such calcium oxide, it is known that a large amount of carbon dioxide gas is generated by a chemical reaction when limestone (calcium carbonate) is fired, and this is cited as one of the problems in aiming for a decarbonized society.

[0003] Also, in the firing of calcium carbonate, a high temperature of 900°C to 1450°C is required, and a large amount of carbon dioxide is emitted by consuming fossil fuels to generate a large amount of thermal energy used for combustion. Therefore, in the production of calcium oxide, a production method capable of reducing the temperature required for firing calcium carbonate has been demanded.

[0004] In order to solve the above problems, a technical proposal described in Patent Document 1 has been made. Specifically, it is a technical proposal for producing quicklime (calcium oxide) by firing limestone (calcium carbonate) in a firing furnace while continuously contacting it with superheated steam. However, in the technical proposal described in Patent Document 1, since the superheated steam in the firing furnace is discharged to the outside together with CO2 generated from calcium carbonate, it is necessary to continuously send superheated steam for firing calcium carbonate. As a result, a large amount of thermal energy is required to continuously generate superheated steam, and thus the above problems have not been solved.

[0005] Therefore, the applicant focused on the temperature and pressure during calcium oxide production and conceived the idea of ​​lowering the calcination temperature required for calcium oxide production by increasing the pressure during calcination while utilizing a catalyst that promotes the chemical reaction during the calcination of calcium carbonate. Based on this idea, the applicant developed a calcium oxide production method that performs calcination at a lower temperature than conventional methods, leading to the proposal of the "Calcium Oxide Production Method and Production Apparatus" in the present invention. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-96876 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In view of the above problems, the present invention aims to provide a method and apparatus for producing calcium oxide that can be fired at a lower temperature than conventional methods. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides a calcium oxide generating apparatus for generating calcium oxide from calcium carbonate, comprising a pressure vessel for chemically reacting the raw materials that are introduced, a heating means, and a carbon dioxide detection means for detecting carbon dioxide in the pressure vessel, wherein the pressure vessel is composed of a calcination chamber, a heating chamber, a mesh plate separating the calcination chamber and the heating chamber, and an adjustment valve for adjusting the pressure in the pressure vessel, wherein calcium carbonate and iron as a catalyst are introduced into the calcination chamber, water is introduced into the heating chamber, the water in the heating chamber is heated by the heating means to vaporize it into superheated steam, the superheated steam in the heating chamber is allowed to flow into the calcination chamber through the mesh plate, and under high temperature and high pressure conditions, calcium oxide and carbon dioxide are generated from the calcium carbonate in the calcination chamber via iron, and the state of calcium oxide generation is confirmed by detecting the carbon dioxide in the pressure vessel with the carbon dioxide detection means.

[0009] Furthermore, the present invention provides a method for producing calcium oxide from calcium carbonate, comprising: an input step of adding calcium carbonate, iron as a catalyst, and water to a pressure vessel; a heating step of heating the water in the pressure vessel until it becomes superheated steam at 350-450°C and a pressure of 10 MPa; a calcination step of producing calcium oxide and carbon dioxide from calcium carbonate via iron in the superheated steam region; and a confirmation step of detecting carbon dioxide in the pressure vessel and confirming the state of calcium oxide production.

[0010] Furthermore, the present invention provides a suction step prior to the heating step, in which air inside the pressure vessel is discharged via a suction pump, and employs a means of performing the heating step with the air inside the pressure vessel diluted. [Effects of the Invention]

[0011] According to the calcium oxide production method and apparatus of the present invention, by vaporizing into superheated steam and calcining calcium carbonate in a pressure vessel, the thermal energy used for the superheated steam also acts inside the pressure vessel, making it possible to increase the thermal efficiency of the heating means. [Brief explanation of the drawing]

[0012] [Figure 1] This is an explanatory diagram showing an embodiment of the calcium oxide production apparatus according to the present invention. [Figure 2] This is a flowchart showing the steps of the calcium oxide production method according to the present invention. [Modes for carrying out the invention]

[0013] The calcium oxide production apparatus and production method according to the present invention are characterized by the fact that calcium carbonate is calcined at high temperature and high pressure in a pressure vessel using a catalyst. Hereinafter, embodiments of the calcium oxide production apparatus and production method according to the present invention will be described with reference to the drawings. Furthermore, the overall configuration and the configuration of each part of the calcium oxide production apparatus and production method according to the present invention are not limited to the embodiments described below, and can be appropriately modified within the scope of the technical idea of ​​the present invention, that is, within the range of shapes, dimensions, structures, etc. that can achieve the same effects.

[0014] Figure 1 is an explanatory diagram showing an embodiment of the calcium oxide production apparatus 10 according to the present invention. Figure 2 is a flowchart showing the steps of the calcium oxide production method 1 according to the present invention. The calcium oxide generating apparatus 10 according to the present invention mainly consists of a pressure vessel 20, a heating means 30, and a carbon dioxide detection means 40.

[0015] The pressure vessel 20 is a sealed container capable of withstanding high pressure used to produce calcium oxide, and has a hollow section inside the container, comprising a calcination chamber 21, a heating chamber 22, and a mesh plate 23. The pressure vessel 20 is a container whose upper and lower ends are closed when the hollow section is sealed. As shown in Figure 1, a firing chamber 21 is provided on the upper side of the hollow section, and a heating chamber 22 is provided on the lower side of the hollow section. A mesh plate 23 is provided at the boundary between the firing chamber 21 and the heating chamber 22. The pressure vessel 20 is a vessel and structure made of materials that can withstand pressures higher than the pressure (10 MPa) that increases in the heating process 3 described later, and at the same time, can withstand temperatures exceeding the firing temperature of 450°C. Furthermore, the pressure vessel 20 is equipped with an adjustment valve 24 and a confirmation valve 41, which can be opened to release the gas inside the pressure vessel 20 to the outside. These are used for adjusting the pressure inside the pressure vessel 20 and for confirming the state of calcium oxide formation in the confirmation process 5. By vaporizing the superheated steam and calcining the calcium carbonate within the pressure vessel 20, the thermal energy used for the superheated steam also acts within the pressure vessel 20, thereby increasing the thermal efficiency of the heating means 30.

[0016] The firing chamber 21 is provided on the upper side of the pressure vessel 20 and is the part where the calcium carbonate is fired. The firing chamber 21 is the part into which the high-temperature and high-pressure superheated steam generated in the heating chamber 22 flows. When the superheated steam fills the firing chamber 21, the temperature of the entire pressure vessel 20 rises to the firing temperature at which the calcium carbonate is fired. At the bottom of the firing chamber 21, which is the boundary between the firing chamber 21 and the heating chamber 22, a mesh plate 23 is provided, and the calcium carbonate and iron introduced into the pressure vessel 20 are placed thereon. Thereafter, the calcium carbonate is fired by the high-temperature and high-pressure superheated steam. In addition, the firing chamber 21 is provided with an adjustment valve 24 for adjusting the pressure in the pressure vessel 20, a thermometer 25 capable of measuring the temperature in the pressure vessel 20, and a pressure gauge 26 capable of measuring the pressure in the pressure vessel 20. And based on the detection results, it will be adjusted to the temperature and pressure required for firing calcium carbonate.

[0017] The heating chamber 22 is provided on the lower side of the pressure vessel 20 and is the part where the water introduced into the pressure vessel 20 is stored while being heated by the heating means 30. Since the heating chamber 22 is also the part where the water is heated by the heating means 30, a structure or material (such as a stainless steel material) that has heat resistance to withstand the heating and is easy to transfer heat to the hollow part of the pressure vessel 20 is used. Also, on the top surface of the heating chamber 22, which is the boundary between the heating chamber 22 and the firing chamber 21, a mesh plate 23 is provided. The water introduced into the compression vessel 20 flows into the heating chamber 22 through the meshes of the mesh plate 23 and is stored at the bottom. At the same time, the superheated steam generated by the heating chamber 22 rises upward through the meshes of the mesh plate 23 and heads towards the firing chamber 21. In the heating chamber 22, all the stored water is vaporized by the heat from the heating means 30, which raises the pressure in the pressure vessel 20. At the same time, the vaporized water is continuously heated to become high-temperature superheated steam, so the temperature in the pressure vessel 20 also continues to rise as the pressure does, and it becomes possible to reach the temperature and pressure required for firing calcium carbonate.

[0018] The mesh plate 23 is provided in the hollow part of the pressure vessel 20 to separate the firing chamber 21 and the heating chamber 22, and is a plate body having a mesh shape. The mesh of the mesh plate 23 is formed to be narrower than the diameters of granular calcium carbonate and iron, so that when the materials are introduced into the pressure vessel 20, the calcium carbonate and iron do not fall into the lower heating chamber 22 and are placed on the top surface of the mesh plate 23. Furthermore, it becomes easier to recover the calcium oxide generated by firing. For example, when the diameters of calcium carbonate and iron are 5 mm in granular form, the mesh of the mesh plate 23 is at least less than 5 mm, preferably about 4 mm in size. The mesh plate 23 is provided so as to cross the hollow part of the pressure vessel 20, and thus serves as both the bottom surface of the firing chamber 21 and the top surface of the heating chamber 22. Then, the calcium carbonate and iron introduced into the pressure vessel 20 are placed on the top surface part of the mesh plate 23, and the water also introduced passes through the mesh and flows into the lower heating chamber 22. Thereafter, the high-temperature and high-pressure superheated steam generated by heating in the heating chamber 22 is sent upward from the mesh of the mesh plate 23 into the firing chamber 21, so that a region filled with superheated steam (hereinafter referred to as the "superheated steam region") is formed around the calcium carbonate and iron in the firing chamber 21, and the temperature rises to the firing temperature.

[0019] The compression vessel 20 naturally has a structure that can be opened and sealed. When each material (calcium carbonate, iron, water) is introduced, the compression vessel 20 is temporarily opened for introduction, and after introduction, it is sealed again. After the generation of calcium oxide is completed, the inside of the compression vessel 20 is brought to normal pressure and then opened to take out the calcium oxide. In addition, the calcium carbonate and iron introduced into the calcium oxide generation device 10 are in granular form with diameters larger than the mesh of the mesh plate 23. Even when each material is introduced from above the compression vessel 20, firing is performed while being placed on the top surface part without falling downward through the mesh of the mesh plate 23. And the water also introduced passes through the mesh of the mesh plate 23 and falls downward to be stored in the bottom surface part of the heating chamber 22.

[0020] The regulating valve 24 is provided in the pressure vessel 20 and is a valve that adjusts the pressure inside the pressure vessel 20. The adjustment valve 24 adjusts the pressure increase caused by the vaporization of water inside the pressure vessel 20. By opening the valve, the gas inside the pressure vessel 20 is released to the outside, thereby reducing the pressure. It is also a valve that releases any remaining air inside the pressure vessel 20 (hereinafter referred to as "residual air") before superheated steam is introduced into the firing chamber 21. There are no particular limitations on the location of the adjustment valve 24, but since opening the adjustment valve 24 causes high-temperature and high-pressure superheated steam and residual air in the pressure vessel 20 to be ejected upward, it is preferable to install it in a position above the firing chamber 21. Although not shown in the diagram, it is also preferable to connect a suction pump that releases air from inside the pressure vessel 20 to the outside to the adjustment valve 24 before heating by the heating means 30, thereby sucking out residual air from inside the pressure vessel 20. By adopting this configuration, the pressure inside the compression vessel 20 is temporarily reduced, which has the excellent effect of lowering the boiling point of the water stored in the heating chamber 22 below that at atmospheric pressure.

[0021] When calcining calcium carbonate inside the pressure vessel 20, a thermometer 25 for measuring the temperature inside the pressure vessel 20 and a pressure gauge 26 for measuring the pressure are provided. The thermometer 25 measures the temperature when superheated steam is generated in the heating chamber 22 and the temperature near the mesh plate 23 where firing takes place, and uses a conventionally known technology. The pressure gauge 26 measures the pressure that increases due to the vaporization of water, and uses conventionally known technology. The pressure gauge 26 will mainly be used to adjust the pressure to a specified level (10 MPa) using the adjustment valve 24. By measuring the temperature and pressure of the pressure vessel 20, it becomes possible to adjust the amount of heating by the heating means 30 and to adjust the pressure that rises as water vaporizes, making it easier to maintain the temperature and pressure conditions necessary for calcining calcium carbonate.

[0022] The heating means 30 is a means for heating the pressure vessel 20, and continues heating after vaporizing the water stored in the heating chamber 22 to create superheated steam, raising it to a specified temperature (350°C to 450°C, preferably 380°C). The heating means 30 can be any conventionally known means that has the ability to heat the water inside the pressure vessel 20. For example, this could include a configuration in which a burner 31, as shown in Figure 1, is installed below the pressure vessel 20, or a configuration in which an electric heater or the like is installed around the pressure vessel 20. The amount of heat generated by the heating means 30 is linked to the measurement results from the thermometer 25, and the amount of heat generated to raise the temperature to the specified temperature and to the time required for firing the calcium carbonate is adjusted as needed, ensuring that the temperature is maintained efficiently until firing.

[0023] In this invention, a carbon dioxide detection means 40 connected to the pressure vessel 20 via a confirmation valve 41 is provided as a means for confirming that the calcination of calcium carbonate and the generation of calcium oxide are taking place. Based on the detection results of this carbon dioxide detection means 40, the calcination status is determined, and a decision is made to continue or stop the calcination. The carbon dioxide detection means 40 detects carbon dioxide from the gas inside the pressure vessel 20 and is used to confirm whether carbon dioxide, which is produced by the chemical reaction from calcium carbonate to calcium oxide, is present in the mixed gas (hereinafter sometimes simply referred to as "mixed gas") that is mixed with superheated steam inside the pressure vessel 20. At this time, by recording the amount of carbon dioxide before the calcination of calcium carbonate, it is also possible to understand the state of calcium oxide formation by comparing it with the state after calcination. The carbon dioxide detection means 40 detects the carbon dioxide gas in the pressure vessel 20 that flows in when the confirmation valve 41 is opened. The detection method can be any conventionally known technology, such as an instrument for measuring carbon dioxide concentration or an instrument for measuring the mass of carbon dioxide contained in the gas.

[0024] The calcium oxide generating apparatus 10 according to the present invention is composed of the above components. Specifically, the calcium oxide generating apparatus 10 is composed of a firing chamber 21 in which calcium carbonate is chemically reacted by firing with superheated steam at high temperature and pressure, a heating chamber 22 in which water is heated until it becomes superheated steam having a specified temperature and pressure, a pressure vessel 20 in which a mesh plate 23 is provided in the hollow part separating the firing chamber 21 and the heating chamber 22, a heating means 30 for heating the pressure vessel 20 to the firing temperature of calcium carbonate, and a carbon dioxide confirmation means 40 for confirming the carbon dioxide contained in the mixed gas in the pressure vessel 20.

[0025] The calcium oxide generating apparatus 10, consisting of the above components, will be described in detail based on Figure 1. First, granular calcium carbonate, iron, and water are introduced into the pressure vessel 20. The calcium carbonate and iron are placed on the top surface of the mesh plate 23, while the water passes through the mesh of the mesh plate 23 and flows into the bottom of the heating chamber 22 where it is stored. Water that flows into and is stored in the heating chamber 22 is heated by the heating means 30, vaporizing and expanding in volume as steam, thereby increasing the pressure inside the pressure vessel 20. After all the water has vaporized by the heating means 30, heating continues, generating superheated steam with the specified temperature (380°C) required for firing. At this time, if the pressure gauge 26 installed in the pressure vessel 20 detects a pressure of 10 MPa or higher, the adjustment valve 24 is opened to reduce the pressure inside the pressure vessel 20. The superheated steam generated in the heating chamber 22 rises through the mesh of the mesh plate 23 and flows into and fills the firing chamber 21, raising the temperature of the calcium carbonate placed on the top surface of the mesh plate 23 while simultaneously bringing the temperature inside the pressure vessel 20 to a temperature suitable for firing the calcium carbonate. Furthermore, since the superheated steam is a gas consisting only of water molecules, the area around the calcium carbonate becomes an inert gas atmosphere, making it less likely for unnecessary chemical reactions and oxidation to occur due to residual air during firing.

[0026] The calcium carbonate on the top surface of the mesh plate 23 and the inside of the calcination chamber 21 are heated to 380°C by the superheated steam that has passed through the mesh plate 23, and the calcium carbonate is calcined. At this time, the iron introduced along with the calcium carbonate acts as a catalyst, and chemical reactions such as oxidation and reduction occur. Furthermore, the high-pressure atmosphere created by the superheated steam reduces the amount of heat required to calcine the calcium carbonate. Furthermore, the calcination of calcium carbonate generates carbon dioxide along with calcium oxide. This generated carbon dioxide then mixes with the surrounding superheated steam to form a gas mixture.

[0027] To check the state of calcium oxide formation, the confirmation valve 41 is opened, allowing a portion of the mixed gas in the pressure vessel 20 to flow into the carbon dioxide confirmation means 40. Based on the detection results from the carbon dioxide confirmation means 40, the progress of the calcium carbonate calcination and the state of calcium oxide formation are checked, and a decision is made to continue or stop the calcination.

[0028] Next, the calcium oxide production method 1 using the calcium oxide production apparatus 10 described above will be explained based on Figure 2. The calcium oxide production method 1 according to the present invention consists of an input step 2, a heating step 3, a calcination step 4, and a confirmation step 5.

[0029] The input process 2 involves adding granular calcium carbonate, iron (a catalyst), and water into the pressure vessel 20. The calcium carbonate and iron are placed on a mesh plate 23, and the water is stored at the bottom of the heating chamber 22. At this stage, by pre-determining and adding the amount of iron required as a catalyst to the calcium carbonate, the calcination process in step 4 can proceed smoothly. Furthermore, it is preferable that the iron be the same shape (granular) as the calcium carbonate to facilitate its catalytic action. Furthermore, the amount of water introduced into the pressure vessel 20 is adjusted so that the pressure inside the pressure vessel 20 is 10 MPa or more in the state of superheated steam.

[0030] Heating step 3 is a step in which the water in the pressure vessel 20 is heated using the heating means 30 until it becomes superheated steam at a specified temperature of 350-450°C and a specified pressure of 10 MPa. The water heated in heating step 3 is water introduced to the bottom of the pressure vessel 20. As the temperature rises, it vaporizes within the sealed pressure vessel 20, increasing both its volume and pressure. By continuing to heat the steam generated by vaporization, it becomes high-temperature, high-pressure superheated steam. The temperature of this superheated steam is preferably 350-450°C, and more preferably 380°C. Furthermore, although the volume increases when the water vaporizes, the pressure inside the pressure vessel 20 also increases simultaneously because the pressure vessel 20 is sealed. The pressure inside the pressure vessel 20, which increases with vaporization, is adjusted to approximately 10 MPa. In heating step 3, the amount of heat from the heating means 30 and the pressure that changes with the vaporization of water are appropriately adjusted using the thermometer 25 and pressure gauge 26 provided in the pressure vessel 20, thereby generating the superheated steam necessary for the next firing step 4.

[0031] Furthermore, it is also preferable to provide a suction step prior to the heating step 3, in which residual air in the pressure vessel 20 is discharged to the outside via a suction pump connected to the adjustment valve 24, and the heating step is performed with the air in the pressure vessel 20 diluted. By incorporating a suction step, a pressure drop occurs inside the container due to the dilution of the air, which lowers the boiling point of water before the heating step 3 can be performed. In this case, it is also preferable to use a carbon dioxide detection means 40 as a means of checking for residual air to detect the presence or absence of carbon dioxide in the pressure vessel 20.

[0032] Firing step 4 is a process in which calcium oxide and carbon dioxide are produced from calcium carbonate using iron as a catalyst in a superheated steam area, and the specified temperature and pressure are maintained by the superheated steam produced in the previous step until the firing of the calcium carbonate is complete. In the firing process 4, the high-temperature and high-pressure superheated steam generated in the previous process fills the compression vessel 20, and the area around the calcium carbonate and iron becomes a superheated steam region, raising the temperature to the firing temperature. Due to the high temperature and pressure, oxidation and reduction reactions and thermal decomposition (firing) occur in the iron, and carbon dioxide and calcium oxide are produced from the calcium carbonate. Furthermore, because the area surrounding the calcium carbonate is a superheated steam region, water molecules exclude other air, creating an inert gas atmosphere. This makes oxidation by oxygen in the residual air less likely. As a result, the catalytic action of iron on calcium carbonate is fully exerted, and the reaction is accelerated compared to an atmospheric environment. In the firing process 4, the iron introduced simultaneously with the calcium carbonate acts as a catalyst, performing oxidation and reduction reactions, thereby accelerating the chemical reaction of calcium carbonate and contributing to the production of calcium oxide at a lower temperature than conventional methods.

[0033] Confirmation step 5 is a step in which carbon dioxide is detected inside the pressure vessel 20 and the state of calcium oxide formation is confirmed. As the calcination process 4 progresses, the carbon dioxide generated simultaneously with the chemical reaction from calcium carbonate to calcium oxide mixes with the superheated steam in the pressure vessel 20 to form a mixed gas. By extracting a portion of the mixed gas filling the pressure vessel 20 and detecting the carbon dioxide contained in that gas with the carbon dioxide detection means 40, it becomes possible to confirm that the calcination of calcium carbonate is taking place in the compression vessel 20. Furthermore, by detecting the carbon dioxide concentration in the pressure vessel 20, it becomes possible to confirm the amount and state of calcium oxide production within the pressure vessel 20. The carbon dioxide detection means 40 used in this process can be any conventionally known technology, and involves taking out a portion of the mixed gas of superheated steam and carbon dioxide that fills the pressure vessel 20 and detecting the carbon dioxide and its concentration in that mixed gas.

[0034] The main production flow of calcium oxide production method 1, which consists of the above components, will now be explained. First, in the input process 2, calcium carbonate, iron, and water are added to the pressure vessel 20. Next, in heating step 3, the water in the pressure vessel 20 is heated, generating high-temperature, high-pressure superheated steam that fills the pressure vessel 20. Then, in the firing process 4, calcium carbonate and iron are fired in the pressure vessel 20, where the temperature and pressure have been increased by superheated steam, thereby generating calcium oxide and carbon dioxide. Furthermore, in order to confirm the state of calcium oxide formation during the calcination process 4, a confirmation process 5 is performed to detect carbon dioxide inside the pressure vessel 20.

[0035] As described above, according to the calcium oxide production method 1 and calcium oxide production apparatus 10 of the present invention, calcium carbonate, iron, and water are placed in the pressure vessel 20, and heating continues even after the water is vaporized by the heating means 30, generating high-temperature and high-pressure superheated steam necessary for calcining calcium carbonate. Furthermore, the iron acts as a catalyst, reducing the temperature required for calcining calcium carbonate, thus enabling the production of calcium oxide at a lower temperature than conventional calcination methods. [Industrial applicability]

[0036] This invention provides a novel method for producing calcium oxide, and at the same time, it is a technology that can significantly reduce the amount of heat required for calcining calcium carbonate, thereby suppressing the generation of carbon dioxide and being useful in realizing a decarbonized society. Therefore, we believe that the industrial applicability of the "calcium oxide production method and production apparatus" according to the present invention is extremely large. [Explanation of Symbols]

[0037] 1. Method for producing calcium oxide 2 Feeding process 3 Heating process 4. Firing process 5 Confirmation process 10 Calcium Oxide Generator 20 Pressure vessels 21 Firing Chamber 22 Heating chamber 23 Mesh plate 24 Adjustment valve 25 Thermometer 26 Pressure gauge 30 Heating means 31 Burner 40. Means of confirming carbon dioxide 41 Confirmation valve

Claims

1. A calcium oxide generating apparatus that produces calcium oxide from calcium carbonate, It consists of a pressure vessel for chemically reacting the raw materials that are introduced, a heating means, and a carbon dioxide detection means for detecting carbon dioxide inside the pressure vessel. The pressure vessel consists of a firing chamber, a heating chamber, a mesh plate separating the firing chamber and the heating chamber, and an adjustment valve for adjusting the pressure inside the pressure vessel. Calcium carbonate and iron, which acts as a catalyst, are placed in the firing chamber, and water is placed in the heating chamber. The heating means heats the water in the heating chamber and vaporizes it into superheated steam. The superheated steam in the heating chamber is introduced into the firing chamber via a mesh plate. Under high temperature and high pressure conditions, calcium oxide and carbon dioxide are produced from calcium carbonate in the firing chamber. A calcium oxide generating apparatus characterized by confirming the state of calcium oxide generation by detecting carbon dioxide in a pressure vessel using a carbon dioxide detection means.

2. A method for producing calcium oxide from calcium carbonate, The process involves adding calcium carbonate, iron (a catalyst), and water to a pressure vessel. A heating step in which the water in the pressure vessel is heated until it becomes superheated steam at 350-450°C and a pressure of 10 MPa, A calcination process in which calcium carbonate is converted into calcium oxide and carbon dioxide via iron within a superheated steam region, A confirmation process that detects carbon dioxide inside the pressure vessel and checks the state of calcium oxide formation, A method for producing calcium oxide consisting of the following components.

3. The method for producing calcium oxide according to claim 2, characterized in that a suction step is provided prior to the heating step, in which air in the pressure vessel is discharged via a suction pump, and the heating step is performed with the air in the pressure vessel diluted.

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