Method for producing low-potassium wood biomass ash, method for reducing potassium in wood biomass ash, method for producing cement, and method for converting wood biomass ash into cement resource

Abstract

To provide a new production method for obtaining low-kalium woody biomass ash from the woody biomass ash.SOLUTION: There is provided a production method for obtaining low-kalium woody biomass ash in which the kalium content in woody biomass ash is reduced. The method comprises: a first process of generating a hydrogen chloride-containing gas by burning a chlorine-containing waste substance under oxidative atmosphere; a second process of heating the woody biomass ash to contact the ash with the hydrogen chloride-containing gas; and a third process of removing a water-soluble component by cleaning the contacted ash using water.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing low-potassium wood biomass ash, a method for reducing potassium in wood biomass ash, a method for producing cement, and a method for converting wood biomass ash into a cement resource. [Background technology]

[0002] Since the start of the Feed-in Tariff Scheme for Renewable Energy (FIT Scheme), the number of certified wood biomass power generation facilities has been on the rise, as stable profits from selling electricity can be expected. As a result, the amount of wood biomass ash generated, which is the ash from the combustion of wood biomass, is expected to increase in the future, and there is a desire to establish a method for its effective use.

[0003] One of the methods to effectively utilize large amounts of wood biomass ash is to use it as a cement resource. However, wood biomass ash contains concentrated potassium, which is contained in plants. If this is used as a cement raw material as is, the amount of alkali metals (sodium and potassium, especially potassium) in the cement will increase, resulting in a decrease in quality. For this reason, there is a need to develop technology to reduce the potassium content in wood biomass ash.

[0004] Conventionally, there have been widely known techniques for reducing the amount of alkali metals in waste containing a large amount of alkali metal components, such as a method of reacting a component containing a chlorine atom with an alkali metal and removing the reacted component by volatilization or washing with water.

[0005] For example, Patent Document 1 discloses a method in which wood biomass ash and solid chlorine-containing waste are mixed together, heated, and washed with water to remove alkali metals. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-157230 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, much of the wood biomass ash generated by wood biomass power generation facilities contains poorly soluble potassium, which is thought to be trapped within the aluminosilicate (crystal) structure and cannot be easily removed.

[0008] Furthermore, Patent Document 1 discloses reacting a solid chlorine-containing material with solid wood biomass ash. However, when two solids are involved, sufficient crushing or mixing is required to uniformly react the chlorine-containing material with the wood biomass ash, which is expected to result in higher processing costs.

[0009] A main object of the present invention is to provide a novel method for producing low-potassium wood biomass ash, which produces wood biomass ash with reduced potassium from wood biomass ash. [Means for solving the problem]

[0010] As a result of intensive research by the inventors to solve the above problems, they discovered that the most practical method for reducing potassium from wood biomass ash is to burn chlorine-containing waste in an oxidizing atmosphere to generate gas containing hydrogen chloride, bring wood biomass ash into contact with the gas containing hydrogen chloride to generate potassium chloride, and then remove the potassium chloride by washing with water, which led to the completion of the present invention.

[0011] One aspect of the present invention relates to a method for producing low-potassium wood biomass ash, which produces wood biomass ash with reduced potassium content from wood biomass ash. The method includes a first step of burning chlorine-containing waste in an oxidizing atmosphere to generate a gas containing hydrogen chloride, a second step of heating the wood biomass ash and bringing the wood biomass ash into contact with the gas containing hydrogen chloride, and a third step of washing the wood biomass ash after the contact with water to remove soluble matter. The wood biomass ash may have an aluminosilicate structure composed of silicon and aluminum. According to the method, the hydrogen chloride-containing gas produced from the chlorine-containing waste is used to sufficiently bring the hydrogen chloride into contact with the wood biomass ash, and the amount of sparingly soluble potassium that is incorporated in the aluminosilicate (crystal) structure of the wood biomass ash is reduced to produce low-potassium wood biomass ash. The low-potassium wood biomass ash has a further reduced potassium content, and can therefore be stably used as a cement raw material.

[0012] In the first step, the chlorine-containing waste is burned in an oxidizing atmosphere. When the chlorine-containing waste is burned in a reducing atmosphere, for example, the frequency of troubles such as pipe blockage tends to increase due to organic components such as tar generated. In addition, in a reducing atmosphere, flammable gas may be generated and hydrogen chloride gas may become highly concentrated, so the cost of gas leakage prevention measures for the equipment tends to be high.

[0013] In the second step, the temperature at which the wood biomass ash is contacted with the gas containing hydrogen chloride (contact temperature) may be 700 to 1100° C. In the second step, the contact time between the wood biomass ash and the gas containing hydrogen chloride may be 1 to 120 minutes.

[0014] The proportion of fly ash in the wood biomass ash may be 60 mass % or more.

[0015] No. 3In the step, the mass ratio of water to the wood biomass ash after contact (mass of water / mass of wood biomass ash after contact) may be 1 to 20. 3 In the step, the water may be hydrochloric acid water containing hydrogen chloride. 2 It may contain hydrochloric acid water obtained by subjecting hydrogen chloride in the gas discharged in the step to gas-liquid contact.

[0016] Another aspect of the present invention relates to a method for reducing potassium in wood biomass ash, which reduces the amount of potassium contained in wood biomass ash. The method includes a first step of burning chlorine-containing waste in an oxidizing atmosphere to generate hydrogen chloride, a second step of heating the wood biomass ash and contacting the wood biomass ash with a gas containing hydrogen chloride, and a third step of washing the wood biomass ash after contact with water to remove soluble matter. The method for reducing potassium can reduce the amount of sparingly soluble potassium that is incorporated in the aluminosilicate (crystal) structure of the wood biomass ash.

[0017] Another aspect of the present invention relates to a method for producing cement, the method comprising the step of using the low-potassium wood biomass ash produced by the above-mentioned method as a cement raw material.

[0018] Another aspect of the present invention relates to a method for converting wood biomass ash into a cement resource, in which the low-potassium wood biomass ash produced by the above-mentioned production method is used as a cement raw material. Effect of the Invention

[0019] According to the present invention, there is provided a novel method for producing low-potassium wood biomass ash, which obtains wood biomass ash with reduced potassium from wood biomass ash. According to the present invention, there is also provided a method for reducing potassium in wood biomass ash, which is capable of reducing the amount of potassium contained in wood biomass ash. Furthermore, according to the present invention, there are provided a method for producing cement using the low-potassium wood biomass ash produced by the above-mentioned production method, and a method for converting wood biomass ash into a cement resource. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing one embodiment of a production facility for low-potassium wood biomass ash. [Diagram 2] FIG. 2 is a schematic diagram showing the reaction apparatus used in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, embodiments of the present invention will be described in detail, however, the present invention is not limited to the following embodiments.

[0022] [Production method for low-potassium wood biomass ash] A method for producing low-potassium wood biomass ash according to one embodiment is for obtaining wood biomass ash having a reduced amount of potassium from wood biomass ash. The method for producing low-potassium wood biomass ash according to the present embodiment includes at least a first step, a second step, and a third step.

[0023] <First step> This process is a process in which chlorine-containing waste is burned in an oxidizing atmosphere to generate gas containing hydrogen chloride.

[0024] Examples of chlorine-containing waste include polyvinyl chloride resin, vinylidene chloride resin, etc. These may be used alone or in mixture, and waste products containing these may be used. Examples of waste products include waste wallpaper, waste carpets, mixed construction waste products, etc.

[0025] The oxidizing atmosphere is not particularly limited as long as it contains oxygen, but the volume concentration of oxygen is preferably 0.1 to 24% by volume. The oxidizing atmosphere may be, for example, an air atmosphere.

[0026] The apparatus (incinerator) for burning chlorine-containing waste is not particularly limited as long as it can burn chlorine-containing waste in an oxidizing atmosphere, but since hydrogen chloride gas is generated, it is preferable that the apparatus is capable of providing a reaction system without gas leakage. Examples of the apparatus (incinerator) for burning chlorine-containing waste include a fluidized bed furnace, a stoker furnace, and a rotary kiln furnace. In addition, fuels such as heavy oil, coal, kerosene, and wood chips may be burned simultaneously to burn the chlorine-containing waste.

[0027] The temperature at which the chlorine-containing waste is burned is preferably 300 to 1100°C, more preferably 350 to 1100°C, further preferably 500 to 1100°C, and particularly preferably 800 to 1000°C.

[0028] This step is usually carried out in a reaction system that allows gas flow and does not leak hydrogen chloride-containing gas. The reaction system in this step is connected to a reaction system for heating the wood biomass ash in the second step described below, whereby the generated hydrogen chloride-containing gas and thermal energy are transferred to the next reaction system, allowing efficient heating of the wood biomass ash.

[0029] <Second step> This step involves heating wood biomass ash and contacting the wood biomass ash with a gas containing hydrogen chloride.

[0030] Woody biomass ash is ash generated when wood resources such as forest residues, sawmill residues, construction waste, and palm kernel shells are burned, and is a concept that includes the bottom ash that accumulates at the bottom of the combustion equipment and the fly ash that is collected by the dust collector. The main elements contained in this woody biomass ash are silicon and aluminum, which form an aluminosilicate structure, and phosphorus and potassium, which are plant nutrients. In woody biomass ash, most of the potassium is thought to be incorporated into the aluminosilicate (crystal) structure and exists in a water-insoluble state.

[0031] The proportion of fly ash in the wood biomass ash is preferably 60 mass % or more, more preferably 70 mass % or more, and even more preferably 80 mass % or more.

[0032] Since this step uses a gas containing hydrogen chloride, it is usually carried out in a reaction system in which gas flow is possible and gas containing hydrogen chloride does not leak. A reaction apparatus (heating reactor) capable of providing such a reaction system can be appropriately selected depending on the amount of woody biomass ash to be treated, and may be either a continuous type or a batch type. Examples of the reaction apparatus (heating reactor) include an apparatus containing a mantle heater, an apparatus containing a tubular furnace, a rotary kiln, a fluidized bed furnace, a moving grate type reactor, a multi-stage furnace reactor, and the like. In addition, such a reaction apparatus (heating reactor) may be configured to have a burner that simultaneously burns fuels such as heavy oil, coal, kerosene, and wood chips in order to maintain the temperature of the reaction apparatus. In addition, the exhaust gas contains volatilized chlorides, and a part of them is discharged together with the exhaust gas and precipitates. Therefore, a device such as a bag filter that removes precipitated chlorides in the exhaust gas of the reaction apparatus may be attached.

[0033] In this step, first, the wood biomass ash is heated to a predetermined temperature (contact temperature). The gas atmosphere of the reaction system during heating may be a gas atmosphere containing hydrogen chloride, or may be another gas atmosphere. The rate of temperature rise during heating is not particularly limited, and can be set arbitrarily depending on the amount of wood biomass ash to be treated, the reaction device, etc.

[0034] Next, the wood biomass ash is contacted with a gas containing hydrogen chloride at a predetermined temperature (contact temperature). When the heating of the wood biomass ash is started in an atmosphere of a gas other than the gas containing hydrogen chloride, the contact between the wood biomass ash and the gas containing hydrogen chloride can be started by starting the introduction of the gas containing hydrogen chloride.

[0035] By contacting wood biomass ash with gas containing hydrogen chloride, the reaction represented by the following formula (1) occurs, and the potassium (KO) contained in the wood biomass ash is converted into water-soluble potassium chloride (KCl). K2O+2HCl→2KCl+H2O (1)

[0036] The contact temperature between the wood biomass ash and the predetermined gas is preferably 700 to 1100° C. If the contact temperature is less than 700° C., the reaction in which potassium (ions) are released from the aluminosilicate structure to produce potassium chloride does not proceed sufficiently, and the reaction 3 Even by this step, potassium tends not to be sufficiently removed. If the contact temperature exceeds 1100°C, the equipment costs and operation costs tend to increase further. The contact temperature is more preferably 800 to 1000°C, and further preferably 900 to 1000°C.

[0037] The contact time between the woody biomass ash and the gas containing hydrogen chloride is preferably 1 to 120 minutes. If the contact time is less than 1 minute, the reaction in which potassium (ions) are released from the aluminosilicate structure to produce potassium chloride tends not to proceed sufficiently. If the contact time exceeds 120 minutes, the potassium removal rate may not be improved, and the equipment costs and operation costs tend to increase. The contact time is more preferably 10 to 120 minutes, further preferably 15 to 120 minutes, and particularly preferably 40 to 90 minutes.

[0038] In addition, the start point of the contact time may be the time when the gas containing hydrogen chloride is introduced (or the time when the gas containing hydrogen chloride is generated) when the gas atmosphere of the reaction system during heating is a gas atmosphere other than the gas containing hydrogen chloride. The time when the gas containing hydrogen chloride is introduced can be determined, for example, by installing a hydrogen chloride concentration meter in the reaction apparatus and observing the change in concentration. In addition, the time when the gas containing hydrogen chloride is introduced can also be determined, for example, based on a relationship between the heating time and the amount of hydrogen chloride generated, which is grasped in advance. In the case where the gas atmosphere of the reaction system during heating is already a gas atmosphere containing hydrogen chloride, the start point of the contact time may be the time when the contact temperature reaches 700°C.

[0039] The average volume concentration of hydrogen chloride in the gas containing hydrogen chloride is preferably 0.01 to 10% by volume. The average volume concentration of hydrogen chloride is more preferably 0.1 to 5% by volume, and further preferably 0.5 to 2% by volume. By adjusting the average volume concentration of hydrogen chloride to such a range, it is possible to obtain a more stable potassium removal effect while suppressing corrosion or deterioration of the equipment. The average volume concentration of hydrogen chloride can be obtained, for example, by installing a concentration meter corresponding to hydrogen chloride in the reaction apparatus and tracking the change in the concentration of hydrogen chloride. In addition, when a gas containing hydrogen chloride of a predetermined concentration prepared in advance is used, the average volume concentration of hydrogen chloride can be a predetermined concentration of hydrogen chloride in the prepared gas. The average volume concentration of hydrogen chloride can be adjusted, for example, by varying the flow rate of air, nitrogen, etc. introduced. When hydrogen chloride generated by burning chlorine-containing waste to be described later is used, the average volume concentration of hydrogen chloride can be adjusted by varying the amount of chlorine-containing waste used, the chlorine content of the chlorine-containing waste, the amount of air introduced, etc.

[0040] The gas containing hydrogen chloride preferably contains oxygen. That is, the atmosphere in which the woody biomass ash and the gas containing hydrogen chloride are contacted may be an oxidizing atmosphere. In this case, the average volume concentration of oxygen in the gas containing hydrogen chloride is preferably 0.1 to 24 volume%, more preferably 5 to 24 volume%, further preferably 10 to 24 volume%, and particularly preferably 15 to 24 volume%. The average volume concentration of oxygen means the average value of the oxygen concentration in the reaction apparatus from the start point to the end point of the contact time. The gas containing hydrogen chloride may contain oxygen, nitrogen, carbon dioxide, etc. in addition to hydrogen chloride.

[0041] The hydrogen chloride-containing gas discharged in this step can be recovered, for example, by gas-liquid contact. The hydrochloric acid solution obtained by gas-liquid contact of the hydrogen chloride in the discharged gas can be used to wash the wood biomass ash in the third step.

[0042] <Third process> This step is a step in which the wood biomass ash after contact is washed with water to remove soluble matter.

[0043] In this step, a certain amount of the woody biomass ash after contact and water are mixed to form a slurry, and the slurry is stirred for a time period that allows sufficient elution of alkali metal salts such as potassium chloride in the woody biomass ash. This step is usually carried out after cooling the woody biomass ash after contact to a temperature of 100° C. or lower (for example, room temperature of 25° C.).

[0044] The wood biomass ash and water after contact can be stirred using a commonly used stirring device. The wood biomass ash and water after contact can be stirred while heating, if necessary.

[0045] In stirring the wood biomass ash and water after contact, the mass ratio of water to the wood biomass ash after contact (mass of water / mass of wood biomass ash after contact) is preferably 1 to 20. If the mass ratio is less than 1, the ionic strength of the water will be too high, tending to reduce the amount of potassium chloride eluted, and the viscosity of the slurry will be too high, tending to reduce transportability. In addition, if the mass ratio exceeds 20, a large amount of water will be required, tending to increase operating costs. The mass ratio is more preferably 3 to 15, and further preferably 5 to 12.

[0046] The water for washing the wood biomass ash may be hydrochloric acid water containing hydrogen chloride. By using hydrochloric acid water, it becomes possible to more sufficiently elute alkali metal salts such as potassium chloride in the wood biomass ash. The concentration of the hydrochloric acid water is not particularly limited, but may be 0.01 to 2 mol / L. The hydrochloric acid water may be a diluted version of commercially available hydrochloric acid water. The hydrochloric acid water may be the first 2 It may contain hydrochloric acid water obtained by subjecting hydrogen chloride in the gas discharged in the step to gas-liquid contact.

[0047] The manufacturing method of this embodiment may further include a step of separating the insoluble wood biomass ash from the soluble matter to obtain low-potassium wood biomass ash. The insoluble wood biomass ash and the soluble matter can be separated by filtration. The residual solid matter obtained by filtration may be dried. When the drying process is performed, the conditions may be, for example, 20 to 300°C and 0.1 to 100 hours.

[0048] 1 is a schematic diagram showing one embodiment of a production facility for low-potassium woody biomass ash. The production facility for low-potassium woody biomass ash includes an incinerator for carrying out the first step, a heating reactor for carrying out the second step, and a water washing facility for carrying out the third step. The production facility for low-potassium woody biomass ash may further include an absorption tower or the like for treating exhaust gas, as necessary.

[0049] The low-potassium wood biomass ash produced by the production method of this embodiment has a sufficiently reduced potassium content, and can therefore be used as a cement raw material.

[0050] [Method for reducing potassium in wood biomass ash] The method for reducing potassium in woody biomass ash according to one embodiment includes a first step of burning chlorine-containing waste in an oxidizing atmosphere to generate hydrogen chloride, a second step of heating the woody biomass ash and contacting the woody biomass ash with a gas containing hydrogen chloride, and a third step of washing the woody biomass ash after contact with water to remove soluble matter. According to the method for reducing potassium, it is possible to reduce the amount of poorly soluble potassium that is incorporated in the aluminosilicate (crystal) structure of the woody biomass ash. The woody biomass ash, reaction device, etc. used in the method for reducing potassium in woody biomass ash are the same as the woody biomass ash, reaction device, etc. used in the method for producing low-potassium woody biomass ash. Therefore, a duplicated description will be omitted here.

[0051] [Cement manufacturing method] A method for producing cement according to an embodiment includes a step of using the low-potassium wood biomass ash produced by the above-mentioned method as a cement raw material. Examples of the step of using the low-potassium wood biomass ash as a cement raw material include a step of mixing the low-potassium wood biomass ash with a cement raw material such as limestone, and a step of feeding the low-potassium wood biomass ash together with a cement raw material such as limestone into a kiln.

[0052] [Method of turning wood biomass ash into cement resource] In one embodiment, a method for converting wood biomass ash into a cement resource uses the low-potassium wood biomass ash produced by the above-mentioned production method as a cement raw material. The low-potassium wood biomass ash produced by the above-mentioned production method has a sufficiently reduced amount of potassium, so it can be used as a cement raw material and can be converted into a cement resource. EXAMPLES

[0053] The present invention will be specifically described below based on examples, but the present invention is not limited to these.

[0054] [Preparation of reactor] The production of low-potassium woody biomass ash was carried out using the following reaction apparatus. FIG. 2 is a schematic diagram showing the reaction apparatus used in the examples. The reaction apparatus 100 shown in FIG. 2 includes a heating section 20 and an exhaust gas trap section 30. The heating section 20 is mainly composed of a ceramic tube 22 filled with woody biomass ash 26 to be heated, and a tubular furnace 24 for heating the ceramic tube 22. The ceramic tube 22 has a connecting pipe 44 connected to the hydrogen chloride generating section 10 and a gas exhaust pipe 46 for exhausting gas in the tubular furnace 24. Hydrogen chloride is introduced into the ceramic tube 22 from the connecting pipe 44. When hydrogen chloride generated by burning chlorine-containing waste is used, hydrogen chloride is generated from the hydrogen chloride generating section 10 and introduced into the ceramic tube 22 from the connecting pipe 44. The exhaust gas trap section 30 is mainly for trapping hydrogen chloride discharged from the gas exhaust pipe 46.

[0055] [Production of low-potassium wood biomass ash] <Verification of hydrogen chloride gas generation from the combustion of chlorine-containing waste> Chlorine-containing plastic (chlorine content: 16% by mass) was used as the chlorine-containing waste. 100 g of chlorine-containing plastic was burned at 1000°C for 60 minutes, and the generation of hydrogen chloride gas was confirmed. The hydrogen chloride generated was dissolved in water and recovered, and the amount of hydrogen chloride generated was quantified. When the chlorine-containing plastic was continuously burned with 1.4 times the theoretical amount of air to prevent incomplete combustion, the hydrogen chloride concentration of the gas generated was 1.1% by volume. The results are shown in Table 1.

[0056] [Table 1]

[0057] In the following Examples 1 to 7, with an emphasis on reproducibility, hydrogen chloride generated by dripping concentrated hydrochloric acid into concentrated sulfuric acid and air were used to prepare a hydrogen chloride-containing gas with a hydrogen chloride volume concentration of 1% by volume (oxygen volume concentration: 21% by volume), and this was used to produce low-potassium wood biomass ash.

[0058] <Production of low-potassium wood biomass ash> Example 1 40 g of woody biomass ash (fly ash ratio: 100% by mass) was filled into a ceramic tube (outer diameter φ50 mm, inner diameter φ42 mm), and the ceramic tube filled with woody biomass ash was placed in a tubular furnace in the heating section. The inside of the tubular furnace was an air atmosphere. Next, the tubular furnace was heated to reach 1000 ° C, and the prepared gas was introduced into the tubular furnace at a flow rate of 15 L / hour. The start point of the contact time between the woody biomass ash and the gas containing hydrogen chloride was set to the time when the gas containing hydrogen chloride was introduced, and the woody biomass ash and the gas containing hydrogen chloride were contacted for 120 minutes. Thereafter, the tubular furnace was cooled to room temperature (25 ° C), and the woody biomass ash after contact was collected. Water was added to the collected woody biomass ash after contact so that the mass ratio of water to the woody biomass ash after contact (mass of water / mass of woody biomass ash after contact) was 10, and the mixture was stirred for 30 minutes to remove soluble matter. Thereafter, the residual solid content was collected by filtration to obtain low-potassium wood biomass ash of Example 1. The potassium amount in the wood biomass ash before contact and the potassium amount in the low-potassium wood biomass ash were measured, and the potassium removal rate was calculated based on the following formula. The results are shown below. 2 As shown in.

[0059] Potassium removal rate (%) = [(absolute amount of K2O in wood biomass ash (g) - absolute amount of K2O in low-potassium wood biomass ash (g)) / absolute amount of K2O in wood biomass ash (g)] x 100

[0060] (Examples 2 to 7) table 2 The contact treatment conditions of Example 1 are shown in Table 2Except for changing the contact treatment conditions to those of Examples 2 to 7, the low-potassium wood biomass ashes of Examples 2 to 7 were obtained in the same manner as in Example 1. The potassium removal rates of Examples 2 to 7 were calculated in the same manner as in Example 1. The results are shown in Table 1. 2 As shown in.

[0061] [Table 2]

[0062] As shown in Table 2, it was confirmed that the manufacturing methods of Examples 1 to 7 were able to sufficiently reduce the amount of potassium in wood biomass ash. Furthermore, it was found that in the manufacturing methods of Examples 1 to 7, when wood biomass ash was contacted at the same temperature, the potassium removal rate from the wood biomass ash tended to increase as the contact time became longer.

[0063] (Examples 8 and 9) The wood biomass ash after contact obtained under the contact treatment conditions of Examples 4 and 7 was dissolved in hydrochloric acid water containing hydrogen chloride (salt discharged from the tubular furnace). transformation The soluble matter was removed using hydrochloric acid (adjusted to a concentration of 0.056 mol / L using exhaust gas trap water obtained by gas-liquid contact of excess hydrogen gas). The residual solid matter was then recovered by filtration to obtain low-potassium wood biomass ashes of Examples 8 and 9. The potassium removal rates of Examples 8 and 9 were calculated in the same manner as in Example 1. The results are shown in Table 3. For comparison, Table 3 also shows the potassium removal rates of Examples 4 and 7.

[0064] [Table 3]

[0065] As shown in Table 3, a comparison between Example 4 and Example 8 and a comparison between Example 7 and Example 9 revealed that the potassium removal rate was improved by washing the wood biomass ash after contact with hydrochloric acid water. [Explanation of symbols]

[0066] 10...hydrogen chloride generation section, 20...heating section, 22...ceramic tube, 24...tubular furnace, 26...wood biomass ash, 30...exhaust gas trap section, 44...connecting pipe, 46...gas exhaust pipe, 100...reaction apparatus.

Claims

1. A method for producing low-potassium wood biomass ash, comprising the steps of: obtaining wood biomass ash having a reduced amount of potassium from wood biomass ash; A first step of burning a chlorine-containing waste material in an oxidizing atmosphere to generate a gas containing hydrogen chloride; A second step of heating wood biomass ash at a temperature of more than 700° C. and not more than 1100° C. and introducing the gas containing hydrogen chloride into the wood biomass ash to contact the gas containing hydrogen chloride; A third step of washing the contacted wood biomass ash with water to remove soluble matter; Equipped with A method for producing low-potassium wood biomass ash.

2. In the second step, the contact time between the wood biomass ash and the gas containing hydrogen chloride is 1 to 120 minutes. The method for producing low-potassium wood biomass ash according to claim 1.

3. The proportion of fly ash in the wood biomass ash is 60% by mass or more. The method for producing low-potassium wood biomass ash according to claim 1 or 2.

4. In the third step, the mass ratio of the water to the wood biomass ash after the contact is 1 to 20. The method for producing low-potassium wood biomass ash according to any one of claims 1 to 3.

5. In the third step, the water is hydrochloric acid water containing hydrogen chloride. The method for producing low-potassium wood biomass ash according to any one of claims 1 to 4.

6. The hydrochloric acid solution includes hydrochloric acid solution obtained by gas-liquid contact of hydrogen chloride in the gas discharged in the second step. The method for producing low-potassium wood biomass ash according to claim 5.

7. A method for reducing the amount of potassium contained in wood biomass ash, comprising: A first step of burning a chlorine-containing waste material in an oxidizing atmosphere to generate hydrogen chloride; A second step of heating wood biomass ash at a temperature of more than 700° C. and not more than 1100° C. and introducing the gas containing hydrogen chloride into the wood biomass ash to contact the gas containing hydrogen chloride; A third step of washing the contacted wood biomass ash with water to remove soluble matter; Equipped with Method for reducing potassium in wood biomass ash.

8. The method includes using the low-potassium wood biomass ash produced by the method according to any one of claims 1 to 6 as a cement raw material. How cement is manufactured.

9. The low-potassium wood biomass ash produced by the production method according to any one of claims 1 to 6 is used as a cement raw material. A method for turning wood biomass ash into a cement resource.

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