Resource recycling device

Abstract

To provide a resource circulation device capable of obtaining high-quality various industrial raw materials by appropriately promoting a gasification reaction using biomass derived from silicic acid plants as a raw material.SOLUTION: A resource circulation device comprises: a raw material supply mechanism that supplies biomass derived from silicic acid plants as a raw material; a first gas supply mechanism that supplies a mixed gas of steam and an oxygen-containing gas; a vertical type reactor formed by arranging a first region, in which the raw material is fluidized and gasified in a jet flow bed formed by the mixed gas, and a second region, in which the gas produced in the first region flows in, in a vertical direction along a gas flow direction; and a second gas supply mechanism that supplies an oxygen-containing gas to the gas flowing into the second region. The second gas supply mechanism includes a first nozzle inclined downward to the center side of the reactor in a vertical direction and a second nozzle inclined downward to the anti-center side of the reactor in the vertical direction, and the first and second nozzles are disposed cyclically along an inner wall of the reactor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a resource recycling device that produces amorphous silica, which is used as various industrial raw materials, from biomass derived from silicate plants, or produces synthesis gas using an aqueous gas reaction or the like.

Background Art

[0002] In Patent Document 1, a gasification furnace that regenerates biomass derived from silicate plants as a facility contributing to the formation of a recycling society has been proposed. The gasification furnace includes a biomass supply unit, a steam supply unit, a first region that fluidizes the biomass supplied from the biomass supply unit in a jet fluidized bed formed by the steam supplied from the steam supply unit, and a second region into which the gas generated in the first region flows. A reaction tower formed by arranging them vertically along the gas flow direction, a plurality of oxygen gas supply units that supply oxygen gas to each of the first region and the second region of the reaction tower, and a supply amount adjustment mechanism that adjusts the gas supply amount from each oxygen gas supply unit.

[0003] In Patent Document 1, a manufacturing apparatus for amorphous silica that can recover energy and obtain high-quality silica with high purity using biomass derived from silicate plants as a raw material has been proposed. The manufacturing apparatus also includes a gasification furnace that fluidizes biomass with steam to cause an aqueous gas reaction and an aqueous gas shift reaction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Each of the gasification furnaces described above comprises a raw material supply mechanism that supplies biomass derived from silicate plants as raw material, a first gas supply mechanism that supplies steam and oxygen-containing gas, a reactor formed by arranging the first region, which is supplied from the first gas supply mechanism and uses a flowbed formed by the gas to flow the raw material and gasify it, and a second region into which the gas generated in the first region flows, in a vertical direction along the direction of gas flow, and a second gas supply mechanism that supplies oxygen-containing gas to the gas flowing into the second region.

[0006] Furthermore, a second gas supply mechanism is disclosed, which is configured to insert a gas supply pipe from the side wall of the second region and eject oxygen-containing gas from a nozzle provided at its tip. This includes nozzles that eject oxygen-containing gas downward from the center of the second region, nozzles that eject oxygen-containing gas from the side wall toward the center, and nozzles that are inclined to generate a swirling flow from the side wall toward the inner wall.

[0007] The gasification furnace described in the aforementioned patent document was a small-scale furnace with a relatively small amount of gas flowing from the first region to the second region, and therefore no particular problems arose in its function as a second gas supply mechanism.

[0008] However, when constructing a gasifier on a larger scale than conventional gasifiers, the conventional second gas supply mechanism is insufficient in terms of effectively and uniformly supplying oxygen-containing gas to the gas flowing from the first to the second region. This leads to problems such as difficulty in adjusting the composition of the incoming gas due to variations in the supply of oxygen-containing gas to the gas flowing into the second region, and the discharge of tiny biomass fragments that remain unburned because the water-gas reaction does not proceed sufficiently in the first region, passing through the second region.

[0009] The object of the present invention is to provide a resource recycling device that can obtain high-quality industrial raw materials by appropriately promoting a gasification reaction using biomass derived from silicate plants as a raw material. [Means for solving the problem]

[0010] To achieve the above objectives, the first characteristic configuration of the resource recycling apparatus according to the present invention is a resource recycling apparatus comprising: a raw material supply mechanism that supplies biomass derived from silicate plants as raw material; a first gas supply mechanism that supplies a mixed gas of water vapor and oxygen-containing gas; a vertical reactor formed by arranging a first region, which is a flowbed formed by the mixed gas supplied from the first gas supply mechanism, into which the raw material is flowed and gasified; and a second region into which the gas generated in the first region flows, in a vertical direction along the gas flow direction; and a second gas supply mechanism that supplies oxygen-containing gas to the gas flowing into the second region, wherein the second gas supply mechanism includes a first nozzle inclined downward toward the center of the reactor with respect to the vertical direction, and a second nozzle inclined downward toward the opposite center of the reactor with respect to the vertical direction, and the first nozzle and the second nozzle are arranged in an annular shape along the inner wall of the reactor.

[0011] Biomass supplied from the raw material supply mechanism flows down to the second region of the reactor, being gasified by water-gas reactions occurring in the jet bed formed by the mixed gas in the first region of the reactor. At this time, oxygen-containing gas is supplied from the second gas supply mechanism to the gas flowing into the second region in a turbulent state, gasifying unburned biomass fragments and adjusting the composition of the gasified components. For example, carbon monoxide is completely combusted into carbon dioxide. This oxygen-containing gas supplied from the second gas supply mechanism is ejected from the first nozzle, which is arranged in a ring along the inner wall of the reactor, toward the center and downward, and from the second nozzle, which is also arranged in a ring along the inner wall of the reactor, toward the opposite side of the reactor, that is, toward the nearest side wall. As a result, mixing of the gas flowing along the side wall from the first region to the second region with the oxygen-containing gas supplied from the second nozzle is promoted, and mixing of the gas flowing towards the central part away from the side wall from the first region to the second region with the oxygen-containing gas supplied from the first nozzle is promoted. Overall, this effectively promotes stirring and mixing with the oxygen-containing gas, allowing for appropriate adjustment of the gas component composition.

[0012] The second characteristic configuration is that, in addition to the first characteristic configuration described above, the first nozzle is inclined downward toward the center of the reactor with respect to the vertical direction at a first inclination angle θ1, and the second nozzle is inclined downward toward the opposite center of the reactor with respect to the vertical direction at a second inclination angle θ2, with the second inclination angle θ2 being set to a smaller value than the first inclination angle θ1.

[0013] To effectively supply oxygen-containing gas injected from the first nozzle to a wide area of ​​gas flowing from the first region to the second region, specifically the central portion away from the side walls, and to promote stirring, it is necessary to set the first inclination angle θ1 to a relatively large value. To effectively supply oxygen-containing gas injected from the second nozzle to a narrow area of ​​gas flowing along the side walls, specifically the gas flowing from the first region to the second region, and to promote stirring, it is necessary to set the second inclination angle θ2 to a relatively small value. By setting the second inclination angle θ2 to a value smaller than the first inclination angle θ1, it is possible to effectively supply oxygen-containing gas to all of the gas flowing from the first region to the second region and promote stirring.

[0014] The third characteristic configuration is that, in addition to the second characteristic configuration described above, the reactor is formed such that the inner diameter of the second region is larger than the inner diameter of the first region, and a gradually expanding diameter section is formed between the first and second regions, and the second gas supply mechanism is positioned in the second region such that the oxygen-containing gas is ejected from the second nozzle toward the expanding diameter section.

[0015] The second region is formed so that its inner diameter is larger than that of the first region, and a gradually expanding diameter section is formed between the first and second regions. As a result, when the gas generated in the first region flows into the second region, its flow velocity decreases, and a circulating flow is formed in which some of the gas returns to the first region. Consequently, the inflow of unburned material into the second region is suppressed. In this environment, oxygen-containing gas injected from the second nozzle is supplied from the second region side toward the expanding diameter section, thereby efficiently supplying oxygen-containing gas to the gas flowing along the inner wall of the expanding diameter section.

[0016] The fourth characteristic configuration is that, in addition to the third characteristic configuration described above, the first inclination angle θ1 is set in the range of 35° ≤ θ1 ≤ 55°, and the second inclination angle θ2 is set in the range of 0° < θ2 ≤ 22°.

[0017] By setting the first inclination angle θ1 and the second inclination angle θ2 within the above-mentioned range, the overall mixture can be effectively promoted to facilitate stirring and mixing with the oxygen-containing gas, allowing for appropriate adjustment of the gas component composition.

[0018] The fifth characteristic configuration is that, in addition to the third characteristic configuration described above, the second gas supply mechanism includes an annular header pipe arranged along the inner wall of the reactor, and the first nozzle and the second nozzle are formed in the header pipe.

[0019] By arranging an annular header tube along the inner wall of the reactor, the first and second nozzles can be effectively positioned within the header tube.

[0020] The sixth characteristic configuration is that, in addition to the third characteristic configuration described above, the amount of oxygen-containing gas supplied from the first nozzle and the amount of oxygen-containing gas supplied from the second nozzle are adjustable.

[0021] Even if there are fluctuations in the flow state and flow rate of the gas flow caused by the biomass composition and the flow rate of the mixed gas supplied from the first gas supply mechanism, the versatility of the second gas supply mechanism is increased if the supply amount of oxygen-containing gas from the first and second nozzles can be adjusted.

[0022] The seventh characteristic configuration is that, in addition to the third characteristic configuration described above, a heat exchanger is provided in the second region, and the second gas supply mechanism is installed below the heat exchanger.

[0023] By stirring and mixing the oxygen-containing gas upstream of the heat exchanger, the composition of the gas components can be adjusted, and the heat exchange efficiency of the heat exchanger also increases. [Effects of the Invention]

[0024] As described above, according to the present invention, it has become possible to provide a resource recycling apparatus that can appropriately obtain various industrial raw materials using biomass derived from silicate plants as a raw material.

Brief Description of the Drawings

[0025] [Figure 1] An example of the resource recycling apparatus according to the present invention is shown, and it is an explanatory diagram of an apparatus for producing amorphous silica. [Figure 2] (a) is a plan view explanatory diagram of the first gas supply mechanism when the heat treatment mainly becomes a combustion reaction, and (b) is a cross-sectional view of the main part of the same first gas supply mechanism. [Figure 3] (a) is a plan view explanatory diagram of the first gas supply mechanism when the heat treatment mainly becomes a gasification reaction, and (b) is a cross-sectional view of the main part of the same first gas supply mechanism. [Figure 4] (a) is a bottom view of the second gas supply mechanism, and FIG. 4(b) is a cross-sectional view taken along the line A-A of (a). [Figure 5] It is an explanatory diagram of a control device provided in an apparatus for producing amorphous silica. [Figure 6] It is an explanatory diagram of simulation results.

Modes for Carrying Out the Invention

[0026] Hereinafter, an example in which the resource recycling apparatus according to the present invention is applied to an apparatus for producing amorphous silica will be described. In FIG. 1, a manufacturing apparatus 1 for amorphous silica, which is an example of a resource recycling apparatus, is shown. The manufacturing apparatus 1 for amorphous silica includes a vertical reactor 2, a raw material supply mechanism 4 that supplies biomass derived from silicate plants as a raw material to the reactor 2, and a first gas supply mechanism 3 that supplies a mixed gas of steam and an oxygen-containing gas to the reactor 2.

[0027] The bottom of reactor 2 is filled with silica sand, which serves as a fluidizing medium for biomass. Biomass supplied from raw material supply mechanism 4 is flowed together with silica sand in a flowbed 9 formed by a mixed gas supplied from first gas supply mechanism 3. A first region R1 is formed along the direction of gas flow, extending from bottom to top, where gasification and temperature adjustment occur through a combustion reaction or water-gas reaction between high-temperature steam and oxygen, and a second region R2 is formed into which the gas generated in the first region R1 flows.

[0028] The reactor 2 is composed of a cylindrical body with a circular cross-section, and is formed such that the inner diameter of the second region R2 is larger than the inner diameter of the first region R1. An expanding diameter section RE is formed between the first region R1 and the second region R2, gradually increasing in diameter from the first region R1 to the second region R2, and an exhaust port 2B is formed at the top 2A of the second region R2. In this embodiment, the inner diameter of the first region R1 is set to 75% of the inner diameter of the second region R2, and the biomass processing capacity is set to 10 tons / day.

[0029] A second gas supply mechanism 6 is further provided to supply oxygen-containing gas to the gas flowing into the second region R2. Unburned gases such as carbon monoxide contained in the gas flowing from the first region R1 to the second region R2 are completely combusted in the second region R2 and discharged outside the furnace through the exhaust port 2B.

[0030] The raw material supply mechanism 4 consists of a screw conveyor mechanism comprising a cylindrical casing and screw blades housed within the cylindrical casing, with the leading end of the casing flange-connected to the side wall of the reactor 2 below the enlarged diameter section RE. Although not shown, a hopper equipped with a raw material quantitative supply mechanism is provided at the base end of the casing.

[0031] The biomass filled into the hopper is supplied in a fixed quantity to the screw conveyor mechanism by the raw material quantitative supply mechanism, compacted and transported through the casing by the screw blades, and then fed into reactor 2. The biomass used is the large amount of rice husks produced after the hulling of paddy rice produced by farmers.

[0032] The first gas supply mechanism 3 comprises a header pipe 30 located on the lower side of the reactor 2, and a plurality of circular diffuser pipes 31 connected to the header pipe 30 in a parallel position to each other. An air supply pipe 32 and a steam supply pipe 33 are connected to the header pipe 30, and a mixed gas of air and steam is supplied to each diffuser pipe 31 via the header pipe 30. Saturated steam or superheated steam is used as the steam.

[0033] A mixed gas supplied from the first gas supply mechanism 3 forms a flowbed 9 at the bottom of the reactor 2 where silica sand flows. In this flowbed 9, the rice husks, which are the raw material, are agitated by the silica sand and subjected to heat treatment and temperature control by the mixed gas, producing amorphous silica as residual ash. The heat treatment includes a combustion reaction in which the carbon components in the rice husks combine with oxygen, and a gasification reaction, which is an endothermic reaction in which the carbon components in the rice husks react with water vapor to produce carbon monoxide and hydrogen.

[0034] The combustion exhaust gas generated by heat treatment in the first region R1 below the enlarged diameter RE of the reactor 2 rises through the furnace along with the amorphous silica, which has been turned into fine powder. The carbon monoxide contained in the combustion exhaust gas is completely combusted by the oxygen-containing gas supplied from the second gas supply mechanism 6 located in the second region R2, and the exhaust gas is discharged from the exhaust pipe 10 connected to the exhaust port 2B of the reactor 2. Note that the flow velocity of the combustion gas generated in the first region R1 decreases as it passes through the enlarged diameter RE, so some of the rice husks that have not been sufficiently heat-treated fall downwards either by their own weight or by the flow of the oxygen-containing gas supplied from the second gas supply mechanism 6. The second gas supply mechanism 6 will be described in detail later.

[0035] Amorphous silica discharged from the exhaust pipe 10 along with the combustion exhaust gas is guided to the cyclone 7, where it is separated from the combustion exhaust gas and recovered. The combustion exhaust gas, after the amorphous silica has been separated, is then subjected to secondary combustion in the secondary combustion equipment 8 before being released into the atmosphere.

[0036] [Configuration of the heat treatment condition control mechanism] The amorphous silica manufacturing apparatus 1 described above is equipped with a heat treatment condition control mechanism A. The heat treatment condition control mechanism A is a mechanism that adjusts the heat treatment conditions of the raw materials supplied to the reactor 2. Even though it is the same manufacturing apparatus 1, it is a mechanism that adjusts the proportion of carbon contained in the amorphous silica produced by switching between mainly combustion reactions and mainly gasification reactions of the raw materials.

[0037] By adjusting the heat treatment state control mechanism A so that a combustion reaction that thoroughly burns off impurities such as carbon contained in the raw material mainly occurs, high-purity amorphous white silica can be obtained. Alternatively, by adjusting the heat treatment state control mechanism A so that a gasification reaction mainly occurs while impurities such as carbon contained in the raw material remain, amorphous black silica can be obtained.

[0038] In this specification, "white silica" refers to amorphous silica in which the proportion of carbon contained in amorphous silica is less than 5% by weight and which has a white or whitish appearance, and "black silica" refers to amorphous silica in which the proportion of carbon contained in amorphous silica exceeds 5% by weight and which has a black or blackish appearance.

[0039] White silica is effectively utilized in industrial materials such as white cosmetic raw materials, adsorbents, and additives for white paints and resins, as well as agricultural materials such as fertilizers for providing silica to crops. Black silica is effectively utilized in industrial materials such as black cosmetic raw materials, adsorbents, additives for black paints and resins, and additives for tires, as well as agricultural materials such as fertilizers for providing silica and carbon to crops.

[0040] The heat treatment state control mechanism A includes an oxygen-containing gas ratio control mechanism (in this embodiment, since air is used as the oxygen-containing gas, it is an air ratio control mechanism) that adjusts the ratio of the oxygen-containing gas supplied from the first gas supply mechanism 3 to the amount of raw material supplied, and a flow state control mechanism that adjusts the flow state of the raw material formed inside the reactor 2 by adjusting at least one of the total amount of gas supplied from the first gas supply mechanism 3, the supply position, and the supply distribution.

[0041] Increasing the total amount of gas makes the flow of the raw material more vigorous, while decreasing the total amount of gas makes the flow of the raw material gentler. By adjusting the distribution of nozzles that supply the gas more densely, the raw material can be agitated so that the contact opportunities between the raw material and the gas are uniform, while by adjusting the distribution of nozzles that supply the gas more loosely, the raw material can be agitated so that the contact opportunities between the raw material and the gas are uneven. By adjusting the distribution of gas supply more densely, the raw material can be agitated so that the contact opportunities between the raw material and the gas are uniform, while by adjusting the distribution of gas supply more loosely, the raw material can be agitated so that the contact opportunities between the raw material and the gas are uneven. For example, even if the distribution of gas supply positions is the same, the gas supply distribution can be adjusted by individually varying the amount of gas supplied from each nozzle.

[0042] Figures 2(a) and 2(b) show the first gas supply mechanism 3(3A) for obtaining white silica by mainly generating a combustion reaction in the reactor 2, and Figures 3(a) and 3(b) show the first gas supply mechanism 3(3B) for obtaining black silica by mainly generating a gasification reaction in the reactor 2. As described above, the first gas supply mechanisms 3(3A,3B) include a header pipe 30 located on the lower side of the reactor 2 and a plurality of diffuser pipes 31 connected to the header pipe 30 in a parallel position to each other. An air supply pipe 32 and a steam supply pipe 33 are connected to the header pipe 30, and a mixed gas of air and steam is supplied to each diffuser pipe 31 via the header pipe 30.

[0043] Each diffuser tube 31 is supported by an attachment 31F with an arc-shaped cross-section that runs along the lower peripheral wall of the reactor 2. The attachment 31F is shaped to cover an arc-shaped notch formed in the lower side wall of the reactor 2, and by fixing the attachment 31F to the side wall of the reactor 2 with the tip of each diffuser tube 31 inserted into the reactor 2, multiple diffuser tubes 31 are fixed to the reactor 2 in a parallel position to each other.

[0044] As shown in Figures 2(a) and 2(b), the diffuser pipes 31 constituting the first gas supply mechanism 3(3A) for the combustion reaction are made up of many small-diameter pipes so that the rice husks supplied from the raw material supply mechanism 4 are uniformly stirred and burned in any plane perpendicular to the axis of the reactor 2 without the creation of locally high-temperature regions.

[0045] As shown in Figures 3(a) and 3(b), the diffuser pipes 31 constituting the first gas supply mechanism 3(3B) for the gasification reaction are made up of a small number of large-diameter pipes so that a large stirring effect can be obtained by allowing the rice husks supplied from the raw material supply mechanism 4 to flow unevenly in any plane perpendicular to the axis of the reactor 2.

[0046] In other words, the first gas supply mechanism 3 (3A, 3B) constitutes a flow state adjustment mechanism, and the flow state of the rice husks is adjusted by using either the first gas supply mechanism 3A or 3B, allowing switching between mainly combustion reactions and mainly gasification reactions. By replacing the first gas supply mechanism 3A with the first gas supply mechanism 3B, the raw material can be mainly subjected to a combustion reaction, and by replacing the first gas supply mechanism 3B with the first gas supply mechanism 3A, the raw material can be mainly subjected to a gasification reaction.

[0047] In other words, the fluid state adjustment mechanism is configured to be adjustable to either a first fluid state in which the distribution of gas supply positions by the first gas supply mechanism 3 is dense to ensure uniform contact with the gas and stir the raw materials, primarily causing a combustion reaction of the raw materials, or a second fluid state in which the distribution of gas supply positions by the first gas supply mechanism 3 is sparse to ensure uneven contact with the gas and stir the raw materials, primarily causing a gasification reaction of the raw materials.

[0048] In the first flow state, the distribution of gas supply locations from the first gas supply mechanism 3 becomes dense, allowing the gas to be supplied uniformly to the raw materials, thus promoting a good combustion reaction. In the second flow state, the distribution of gas supply locations from the first gas supply mechanism 3 becomes sparse, creating regions where the raw materials rise with the upward flow of gas and regions where the raw materials descend without gas supply, thus promoting a good gasification reaction.

[0049] In the first fluid state, the distribution of air supply positions in a plan view from the first gas supply mechanism 3 becomes dense, allowing the rice husks to flow uniformly in the fluidized bed and the space above it, providing a stable opportunity for contact with air and promoting a good combustion reaction. In the second fluid state, the distribution of air supply positions in a plan view from the first gas supply mechanism 3 becomes sparse, creating regions where a large upward flow occurs over the rice husks due to the supply of air, and regions where a downward flow occurs over the rice husks due to the lack of air supply. The stirring effect caused by the uneven upward and downward movement of the rice husks in the fluidized bed and the space above it promotes a good gasification reaction.

[0050] The above explanation described an example of adjusting the distribution of gas supply locations to control the flow state. However, to control the flow state, it is sufficient to adjust at least one of the total amount of gas, supply location, or supply distribution, and it is also possible to adjust any or all of these in combination.

[0051] Returning to Figure 1, compressed air supplied from a compressor or blower fan is supplied to the air supply pipe 32 connected to the header pipe 30, and the amount supplied is regulated by a valve 32V (or damper) provided on the air supply pipe 32. In addition, superheated steam generated by a heat exchanger in the secondary combustion equipment 8 or superheated steam generated by a heat recovery mechanism 5, which is a heat exchanger in the reactor 2, is supplied to the steam supply pipe 33 connected to the header pipe 30, and the amount supplied is regulated by a valve 33V (or damper) provided on the steam supply pipe 33. Reference numeral 34 denotes a steam flow meter.

[0052] Valve 32V functions as an air ratio adjustment mechanism, and by adjusting the air ratio to the rice husks supplied from the raw material supply mechanism 4, it is possible to adjust whether the rice husks undergo a combustion reaction or a gasification reaction.

[0053] The air-fuel ratio adjustment mechanism is a mechanism that adjusts the air-fuel ratio to rice husks to either a first range where the theoretical air-fuel ratio to rice husks is greater than 1, in order to primarily combust the rice husks, or a second range where the theoretical air-fuel ratio is less than 1, in order to primarily gasify the rice husks.

[0054] By adjusting the air-to-rice husk ratio to a first range greater than the theoretical air ratio of 1, the rice husks can be efficiently combusted. By adjusting it to a second range less than the theoretical air ratio of 1, the rice husks can be efficiently gasified.

[0055] The first range is preferably one in which the air ratio is between 1.3 and 1.7. If the air ratio is less than 1.3, carbon components remain in the silica, and high-quality white silica cannot be obtained. If the air ratio is greater than 1.7, the amount of heat carried out by excess air increases, the combustion temperature decreases, and a good combustion state cannot be maintained. The second range is preferably one in which the air ratio is between 0.2 and 0.5. If the air ratio is less than 0.2, thermal decomposition is not promoted, and if the air ratio is greater than 0.5, some of the carbon burns, and good black silica cannot be obtained.

[0056] Furthermore, when using a gas other than air, such as oxygen-enriched air, as the oxygen-containing gas, the rice husk raw material can be efficiently combusted by adjusting the ratio of the oxygen-containing gas to the raw material to a first range where the ratio is greater than the theoretical air ratio of 1 when converted to an air ratio, via the oxygen-containing gas ratio adjustment mechanism. Alternatively, the rice husk raw material can be efficiently gasified by adjusting the ratio to a second range where the ratio is less than the theoretical air ratio of 1 when converted to an air ratio. When using oxygen-enriched air, the amount of gas decreases, so the flow state of the raw material may be adjusted by adjusting the total amount of gas supplied from the gas supply mechanism.

[0057] Similarly, the first range is preferably 1.3 or more and 1.7 or less, and the second range is preferably 0.2 or more and 0.5 or less.

[0058] By using the first gas supply mechanism 3(3A) for the combustion reaction shown in Figures 2(a) and 2(b) as the first gas supply mechanism 3, a manufacturing apparatus 1 for obtaining white amorphous silica can be realized. The control device (see Figure 5) adjusts the opening of valve 32V so that the air ratio is in the range of 1.3 to 1.7, and adjusts the temperature in the first region R1 below the enlarged diameter RE of the reactor 2 to be in the range of 400°C to 600°C. In addition, the amount of air supplied from the second gas supply mechanism 6 via valve 6V (described later) and the amount of heat recovered by the heat recovery mechanism 5 via valve 5V are adjusted so that the temperature in the second region R2 above the enlarged diameter of the reactor 2 is in the range of 750°C to 850°C. For this purpose, the outputs of the first temperature sensor TH1 and the second temperature sensor TH2 installed on the downstream and upstream sides of the heat recovery mechanism 5 are input to the control device.

[0059] The combustion reaction at this time is represented by the following reaction equation. C + O2 → CO2 CO + (1 / 2)·O2 → CO2

[0060] By using the first gas supply mechanism 3(3A) for the gasification reaction shown in Figures 3(a) and 3(b) as the first gas supply mechanism 3, a manufacturing apparatus 1 for obtaining black amorphous silica can be realized. The control device (see Figure 5) adjusts the opening of valve 32V so that the air ratio is in the range of 0.2 to 0.5, and adjusts the amount of air supplied from the second gas supply mechanism 6 via valve 6V (described later) so that the temperature in the first region R1 of the reactor 2 is in the range of 500°C to 600°C, and the temperature in the second region is in the range of 700°C to 800°C. At this time, the steam supplied to the steam supply pipe 33 is superheated steam generated in the heat exchanger provided in the secondary combustion equipment 8.

[0061] The gasification reaction in this process is primarily a water-gas reaction. A water-gas reaction is an endothermic reaction in which carbon monoxide (CO) and hydrogen (H2) are produced from solid carbon (C), which is biomass, and water vapor (H2O) under high-temperature conditions of 500°C or higher, as shown in the following equation. By supplying a small amount of air in addition to the steam to the reactor 2, the necessary reaction heat is provided by the combustion of a portion of the rice husks, and the internal temperature of the reactor is maintained at a high temperature of 500°C or higher. Furthermore, the carbon monoxide is completely combusted by the oxygen-containing gas supplied by the second gas supply mechanism 6. C + H2O → CO + H2 CO + (1 / 2)·O2 → CO2

[0062] In this embodiment, superheated steam with a pressure of 1 MPa or less and a temperature of 120°C to 160°C is supplied from the steam supply pipe 33. The steam supplied to reactor 2 is used for initial heating of the raw materials, for activation including increasing the specific surface area of ​​silica through water-gas reaction and combustion reaction, and to suppress abnormal increases in the ambient temperature inside the furnace due to the subsequent combustion reaction. The amount supplied is appropriately regulated by valve 33V. When primarily a water-gas reaction is being carried out, the proportion of water vapor is increased to promote activation, and the minimum amount of oxygen-containing gas necessary to maintain the furnace temperature is supplied. When primarily a combustion reaction is being carried out, the proportion of oxygen-containing gas is increased to promote the combustion reaction, and water vapor has the effect of suppressing the generation of localized high-temperature fields due to the combustion reaction.

[0063] [Configuration of the second gas supply mechanism] As shown in Figures 1 and 4(a) and 4(b), the second gas supply mechanism 6 consists of an air supply pipe 6A installed downward from an exhaust port 2B located at the top 2A of the reactor 2, and an annular header pipe 6B with a circular cross-section connected to the lower end of the air supply pipe 6A. Multiple first nozzles N1 and multiple second nozzles N2 are formed in the header pipe 6B, arranged in an annular pattern at predetermined pitches. A flow rate adjustment valve 6V is installed in the air supply pipe 6A. The header pipe 6B is installed in the second region R2 directly below the heat exchanger 5.

[0064] The furnace top section 2A is detachably flange-connected to the side wall of the reactor 2, and by removing the furnace top section 2A from the side wall, the heat exchanger 5 and the second gas supply mechanism 6 can be removed from inside the reactor 2 for maintenance, and then reinstalled inside the reactor 2.

[0065] The first nozzle N1 and the second nozzle N2 are formed as openings that are inclined by predetermined angles θ1 and θ2, respectively, with respect to a vertical line V passing through the center O2 of the cross-section of the annular header pipe 6B, on a vertical plane that includes the center O1 of the annular header pipe 6B and the formation position of each nozzle.

[0066] Therefore, oxygen-containing gas is injected from the first nozzle N1 in a direction with a first inclination angle θ1 toward the center and downward relative to the vertical line V, and oxygen-containing gas is injected from the second nozzle N2 in a direction with a second inclination angle θ2 toward the opposite side of the center of the reactor 2, that is, toward the immediate inner wall, toward the vertical line V. The second inclination angle θ2 is set to a smaller value than the first inclination angle θ1. Alternatively, cylindrical bodies may be installed so as to protrude from each opening, and these cylindrical bodies may constitute the first nozzle N1 and the second nozzle N2.

[0067] Mixing of gas G2, which flows along the side wall (inner wall) of the enlarged diameter section RE, with the oxygen-containing gas supplied from the second nozzle N2 is promoted among the gases flowing from the first region R1 to the second region R2 of reactor 2. Mixing of gas G1, which flows towards the central part away from the side wall (inner wall) of the enlarged diameter section RE, with the oxygen-containing gas supplied from the first nozzle N1 is promoted among the gases flowing from the first region R1 to the second region R2 of reactor 2. In both cases, unburned biomass fragments contained in the gas flowing into the second region R2 are made to fall towards the first region R1, thereby effectively promoting stirring and mixing with the oxygen-containing gas as a whole.

[0068] The oxygen-containing gas injected from the second nozzle N2 is supplied from the second region R2 towards the enlarged diameter section RE, thereby efficiently supplying the oxygen-containing gas to the gas flowing along the inner wall of the enlarged diameter section RE.

[0069] The diameter of the header tube 6B, that is, the diameter from the center O1 of the header tube 6B to the center O2 of the cross-section of the header tube 6B, can be appropriately set according to the diameter of the reactor 2, and it is preferable to set it in the range of 60 to 90% of the diameter of the second region R2.

[0070] Furthermore, 36 first nozzles N1 and 36 second nozzles N2 are formed at intervals of 10° from the center O1, and the distance between the first nozzles N1 and the second nozzles N2 is 5° from the center O1. The opening diameter of the first nozzles N1 and the second nozzles N2 is set to 5 mm each.

[0071] The diameter of the header pipe 6B is preferably set to a value that is at least equal to or greater than the diameter of the first region R1 and less than the diameter of the second region R2. Furthermore, the diameter of the cross-section of the header pipe 6B is preferably about 5 to 10% of the diameter of the header pipe 6B. This is because if the diameter of the cross-section of the header pipe 6B is too large, it will obstruct the flow of gas into the second region R2.

[0072] The first inclination angle θ1 is preferably set in the range of 35° ≤ θ1 ≤ 55°, and more preferably in the range of 40° ≤ θ1 ≤ 50°. The second inclination angle θ2 is preferably set in the range of 0° < θ2 ≤ 22°, and even more preferably in the range of 10° < θ2 ≤ 17.5°. By setting the first inclination angle θ1 and the second inclination angle θ2 within the above ranges, the mixing with the oxygen-containing gas can be effectively promoted as a whole, and the composition of the gas components can be appropriately adjusted.

[0073] Furthermore, it is preferable that the supply amount of oxygen-containing gas supplied from the first nozzle N1 and the supply amount of oxygen-containing gas supplied from the second nozzle N2 be adjustable. The adjustment state by the heat treatment state adjustment mechanism A described above allows for good heating even when the state of the gas flowing from the first region R1 to the second region R2 changes. For example, this can be achieved by making the opening diameters of the first nozzle N1 and the second nozzle N2 different. Alternatively, a separate header pipe for the first nozzle N1 and a separate header pipe for the second nozzle N2 may be provided, and the opening degree of the valve 6V provided on the air supply pipe connected to each header pipe may be adjusted individually.

[0074] Even if there are fluctuations in the flow state and flow rate of the gas flow caused by the biomass composition and the flow rate of the mixed gas supplied from the first gas supply mechanism 3, the versatility of the second gas supply mechanism is increased if the supply amount of oxygen-containing gas from the first nozzle N1 and the second nozzle N2 can be adjusted.

[0075] Figure 5 shows the configuration of the control device C that controls the amorphous silica manufacturing apparatus 1. The control device C receives input from sensors such as the first temperature sensor TH1, the second temperature sensor TH2, the steam flow meter 34, and the steam temperature sensor TH3 which detects the temperature of the steam output from the boiler in the secondary combustion equipment 8. It also receives an identification signal indicating whether the heat treatment state adjusted by the heat treatment state adjustment mechanism mainly promotes a combustion reaction or mainly promotes a gasification reaction.

[0076] When the heat treatment state adjusted by the heat treatment state adjustment mechanism is mainly a combustion reaction, the control device C adjusts the opening of valve 32V and valve 6V to adjust the amount of air supplied from the second gas supply mechanism 6, based on the value of the second temperature sensor TH2, so that the combustion temperature of the first region of the reactor 2 falls between 500°C and 600°C, and also adjusts the opening of valve 33V. Furthermore, based on the value of the first temperature sensor TH1, the control device C adjusts the flow rate of boiler water supplied to the heat recovery mechanism 5 by adjusting the opening of valve 5V so that the combustion temperature of the second region R2 of the reactor 2 falls between 750°C and 800°C, that is, so that the temperature is lower than the phase transition temperature range in which amorphous silica crystallizes.

[0077] When the heat treatment state adjusted by the heat treatment state adjustment mechanism is mainly a gasification reaction, the control device C adjusts the opening of valve 32V and the amount of air supplied from the second gas supply mechanism 6, and also adjusts the opening of valve 33V, based on the value of the second temperature sensor TH2, so that the combustion temperature of the first region R1 of the reactor 2 falls between 500°C and 600°C, and based on the value of the first temperature sensor TH1, so that the combustion temperature of the second region R2 falls between 700°C and 800°C.

[0078] In this case, if the combustion temperature in the second region R2 does not exceed 800°C, there is no need to adjust the flow rate of boiler water supplied to the heat recovery mechanism 5. The second temperature sensor TH2 can be located where it can monitor the temperature of the first region R1, and may be installed in either the first region R1 or the second region R2, as long as it is upstream of the heat recovery mechanism 5.

[0079] In this embodiment, rice husks are used as biomass, but the application of the present invention is not limited to rice husks. It is also possible to use biomass derived from silicate plants such as rice straw, wheat straw, bamboo, corn, sugarcane, pampas grass, and horsetail.

[0080] In the embodiments described above, an example was explained in which the first gas supply mechanism 3 is configured to supply a mixed gas of water vapor and air, which is an example of an oxygen-containing gas. However, as long as the oxygen-containing gas ratio adjustment mechanism and the flow state adjustment mechanism are provided as described above, the water vapor and oxygen-containing gas may be supplied separately.

[0081] To ensure good contact between the raw materials and the gas, the particle size of the silica sand is preferably in the range of 0.05 mm to 2 mm. Furthermore, if the raw materials can be heat-treated while in contact with the gas inside the reactor 2, it is not essential to introduce silica sand into the reactor 2.

[0082] Although the amorphous silica production apparatus has been described above as a resource recycling device, the resource recycling device of the present invention may also be applied to a gasifier in a plan such as the one described in Patent Document 1, in which non-edible raw materials such as rice straw, rice husks, and wood chips are fed into a gasifier and gasified by a water-gas reaction, and the resulting gas is converted into liquid fuel by FT synthesis, and the second gas supply mechanism described above is incorporated to adjust the ratio of hydrogen gas to carbon monoxide gas, H2 / CO.

[0083] This section explains the results of a simulation conducted to verify the specific structure of the second gas supply mechanism described above. Using the general-purpose thermal fluid analysis software Fluent ver.18.0, and based on a full-scale three-dimensional thermal fluid analysis model corresponding to the amorphous silica manufacturing apparatus described in the above embodiment, we simulated the structure of a second gas supply mechanism that can achieve a biomass processing capacity of 10 tons / day while achieving a specified target amount (60 ppm in this case) for carbon monoxide gas concentration in the gas effluent from the reactor. Specifically, we simulated the appropriate values ​​of the first inclination angle θ1 and the second inclination angle θ2, using vorticity as the evaluation index.

[0084] The analysis model had approximately 3.55 million meshes. The Realizable k-ε model was used for turbulence, and the DO model was used for radiation. Gas samples were taken from the first region R1 in Figure 2, and the amounts of combustible components H2 (hydrogen), CH4 (methane), C2H4 (ethylene), CO (carbon monoxide), and C (carbon) were determined from the results of component analysis. The combustion of these combustible components was modeled using a finite velocity / vortex dissipation model in general-purpose software, as shown in the following equation. H2+ 1 / 2O2 → H2O CH4 + 2O2 → CO2 + 2H2O C2H4 + 2O2 → 2CO2 + 2H2O CO+ 1 / 2O2 → CO2 C + O2 → CO2

[0085] As a result, the results shown in Figure 8 were obtained, and their consistency with the verification results of the actual furnace was confirmed. Specifically, it was found that when the first tilt angle θ1 = 45°, it is preferable that the value of the second tilt angle θ2 be set in the range of 0° < θ2 ≤ 22°, and even more preferable that it be set in the range of 10° < θ2 ≤ 17.5°.

[0086] The above description is merely one specific example of a resource recycling device according to the present invention, and the scope of the present invention is not limited by this description. Furthermore, it goes without saying that the specific configuration of each part can be appropriately modified and designed within the scope in which the effects of the present invention are achieved. [Explanation of symbols]

[0087] 1: Amorphous silica manufacturing equipment 2: Reactor 3: First Gas Supply Organization 30: Header pipe 31: Diffusion pipe 32: Air supply pipe 32V: Bulb 33: Steam supply pipe 33V: Bulb 4: Raw material supply mechanism 5: Heat recovery mechanism 6: Second Gas Supply Organization 6A: Air intake pipe 6B: Header tube 6V: Bulb N1: First nozzle N2: Second nozzle 7: Cyclone 8: Secondary combustion equipment 9: Splash floor 10: Exhaust pipe A: Heat treatment condition control mechanism

Claims

1. A raw material supply mechanism that supplies biomass derived from silicate plants as raw material, A first gas supply mechanism that supplies oxygen-containing gas, A vertical reactor is formed by arranging a first region, into which the raw material is flowed and gasified in a jet bed formed by the oxygen-containing gas supplied from the first gas supply mechanism, and a second region into which the gasified gas in the first region flows, in a vertical direction along the gas flow direction. A second gas supply mechanism that supplies oxygen-containing gas to the gas flowing into the second region, A biomass processing device equipped with, The second gas supply mechanism includes a first nozzle inclined downward toward the center of the reactor with respect to the vertical direction, and a second nozzle inclined downward toward the opposite center of the reactor with respect to the vertical direction, wherein the first nozzle and the second nozzle are arranged in an annular shape along the inner wall of the reactor.

2. The biomass processing apparatus according to claim 1, wherein the first nozzle is inclined downward toward the center of the reactor with respect to the vertical direction at a first inclination angle θ1, and the second nozzle is inclined downward toward the opposite center of the reactor with respect to the vertical direction at a second inclination angle θ2, wherein the second inclination angle θ2 is set to a value smaller than the first inclination angle θ1.

3. The reactor is formed such that the inner diameter of the second region is larger than the inner diameter of the first region, and a gradually expanding diameter section is formed between the first region and the second region. The biomass processing apparatus according to claim 2, wherein the second gas supply mechanism is arranged in the second region such that the oxygen-containing gas is ejected from the second nozzle toward the enlarged diameter portion.

4. The biomass processing apparatus according to claim 3, wherein the first inclination angle θ1 is set in the range of 35° ≤ θ1 ≤ 55°, and the second inclination angle θ2 is set in the range of 0° < θ2 ≤ 22°.

5. The biomass processing apparatus according to claim 3, wherein the second gas supply mechanism comprises an annular header pipe arranged along the inner wall of the reactor, and the first nozzle and the second nozzle are formed in the header pipe.

6. The biomass processing apparatus according to claim 3, wherein the amount of oxygen-containing gas supplied from the first nozzle and the amount of oxygen-containing gas supplied from the second nozzle are configured to be adjustable.

7. The biomass processing apparatus according to claim 3, wherein a heat exchanger is provided in the second region, and the second gas supply mechanism is installed below the heat exchanger.

Images