Manufacturing method of solid fuel, manufacturing device of solid fuel, and solid fuel

Abstract

To provide a manufacturing method of a solid fuel having high productivity and capable of manufacturing a solid fuel having high compression strength.SOLUTION: In a manufacturing method of a solid fuel for manufacturing a solid fuel from a crude drug residue, the manufacturing method of a solid fuel includes steps of: drying the crude drug residue in a manner that a moisture content of the crude drug residue becomes 3 mass% or more to 10 mass% or less; and pressing the crude drug residue under a pressure of 100 MPa or more by using a molding cylinder including a piston.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing solid fuel, an apparatus for producing solid fuel, and solid fuel. [Background technology]

[0002] A batch method is known as one of the conventional methods for producing solid fuels such as bio-coke. As a batch method, for example, a bio-coke production method is known in which biomass granules are filled into a bottomed cylindrical reaction vessel, and the biomass granules are press-molded while being heated in a substantially dense state within a temperature and pressure range to obtain semi-carbonized or semi-carbonized solid matter, and then cooled to produce bio-coke (see, for example, Patent Document 1).

[0003] However, conventional batch-type methods have the problem of low processing capacity and low productivity of solid fuel because they require the loading of biomass raw materials, which is also the case when using herbal medicine residues as raw materials.

[0004] Furthermore, when producing solid fuel from biomass materials such as herbal residues, the water contained in the herbal residues is pressurized and heated in a sealed cylinder, reaching a subcritical state, causing components such as cellulose, hemicellulose, and lignin to decompose and soften. By cooling while applying pressure, the decomposed and softened components combine to produce solid fuel. If cooling is not performed while applying pressure, the subcritical water will turn into steam, which can lead to steam explosions or cracks caused by the release of steam, making it impossible to mold the solid fuel or significantly reducing its compressive strength. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-100815 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to solve the above-mentioned problems in the prior art and to achieve the following object: That is, the present invention aims to provide a method for producing solid fuel that has high productivity and is capable of producing solid fuel having high compressive strength. [Means for solving the problem]

[0007] The means for solving the above problems of the present invention are as follows. <1> A method for producing solid fuel from herbal residue, comprising: a drying step of drying the herbal medicine residue so that the moisture content of the herbal medicine residue is 3% by mass or more and 10% by mass or less; a pushing step of pushing the herbal medicine residue at a pressure of 100 MPa or more using a molding cylinder equipped with a piston; The method for producing a solid fuel is characterized by comprising the steps of: <2> A crushing step of crushing the herbal medicine residue so that the particle size of the herbal medicine residue is 2 mm or less is included. <1> 1. A method for producing a solid fuel according to claim 1. <3> The herbal medicine residue includes at least one of herbaceous roots and herbaceous stems, <1> from <2> 1. A method for producing a solid fuel according to any one of the above. <4> After the pushing step, the method includes a slow cooling step of slowly cooling the herbal drug residue while supporting the herbal drug residue with a support member that is in partial contact with the pushed herbal drug residue. <1> from <3> 1. A method for producing a solid fuel according to any one of the above. <5> In the slow cooling step, the herbal medicine residue is slowly cooled to a temperature of 80°C or less. <4> 1. A method for producing a solid fuel according to claim 1. <6> In the slow cooling step, the herbal medicine residue is slowly cooled at a temperature decreasing rate of 3°C / min or more and 20°C / min or less. <4> from <5> 1. A method for producing a solid fuel according to any one of the above. <7> In the slow cooling step, the herbal medicine residue is sandwiched between at least two of the support members at a pressure of 200 N or more and 500 N or less per 800 mm length from the outer periphery to the center of the herbal medicine residue. <4> from <6> 1. A method for producing a solid fuel according to claim 1. <8> In the pushing step, the herbal residue is pushed using a molding cylinder having a diameter of 40 mm or more and 120 mm or less, with a pushing length of 150 mm or more and 200 mm or less. <1> from <7> 1. A method for producing a solid fuel according to any one of the above. <9> In the pushing step, the piston in the molding cylinder is driven at a rotation speed of 300 rpm or more. <1> from <8> 1. A method for producing a solid fuel according to any one of the above. <10> In the pushing step, the molding cylinder is heated to 120°C or higher and 200°C or lower. <1> from <9> 1. A method for producing a solid fuel according to any one of the above. <11> A solid fuel manufacturing apparatus for manufacturing solid fuel from herbal medicine residue, a drying means for drying the herbal medicine residue so that the moisture content of the herbal medicine residue is 3% by mass or more and 10% by mass or less; This solid fuel manufacturing device is characterized by having a thrusting means capable of thrusting the herbal medicine residue inside the molding cylinder at a pressure of 100 MPa or more. <12> The molding cylinder has a diameter of 40 mm or more and 120 mm or less, and a pushing length of 150 mm or more and 200 mm or less. <11> 2. The solid fuel manufacturing apparatus according to claim 1. <13> A crushing means for crushing the herbal medicine residue to a particle size of 2 mm or less is provided. <11> from <12> 1. The solid fuel manufacturing apparatus according to claim 1, wherein the solid fuel is a fuel having a diameter of 100 mm or less. <14> <1> from <10> A solid fuel obtained by the method for producing a solid fuel according to any one of the above. The solid fuel is characterized by an apparent specific gravity of 1.05 or more and 1.30 or less, and a compressive strength of 10 MPa or more and 40 MPa or less. [Effects of the Invention]

[0008] According to the present invention, the above-mentioned problems of the prior art can be solved and the following object can be achieved: That is, the present invention can provide a method for producing solid fuel with high productivity and capable of producing solid fuel having high compressive strength. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an overall schematic view showing an example of a solid fuel production apparatus according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a process of forming solid fuel by a thrusting means of a solid fuel manufacturing apparatus according to an embodiment of the present invention. [Figure 3] 3 is a schematic cross-sectional view showing an example of a support member in the slow cooling means of the solid fuel production apparatus according to one embodiment of the present invention. FIG. [Figure 4] FIG. 10 is a schematic cross-sectional view showing another example of a support member in the slow cooling means of the solid fuel production apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Solid fuel manufacturing method and solid fuel manufacturing device) The method for producing a solid fuel of the present invention includes a drying step and a pushing step, and may further include other steps such as a crushing step and a slow cooling step as required. The solid fuel manufacturing apparatus of the present invention includes a drying means and a thrusting means, and may further include other means such as a crushing means and a slow cooling means as required. The pushing step can be performed by the pushing means, the crushing step can be performed by the crushing means, and the drying step can be performed by the drying means.

[0011] FIG. 1 is a schematic overall view showing an example of an apparatus for producing solid fuel according to one embodiment of the present invention. The solid fuel manufacturing device 100 has an inlet 10 for feeding the herbal medicine residue, a screw 20 as a means for feeding the herbal medicine residue, a piston and molding cylinder 30B as a thrusting means, and an outlet 40 for discharging the solid fuel.

[0012] FIG. 2 is a schematic diagram showing the process up to the formation of solid fuel by the thrusting means of the solid fuel manufacturing device according to one embodiment of the present invention. The crude drug residue introduced through the introduction port 10 shown in FIG. 1 is supplied by a screw 20 to a molding cylinder 30B serving as a thrusting means, as shown in FIG.

[0013] The herbal residue supplied to the molding cylinder 30B is thrust by the piston 30A at a pressure of 100 MPa or more, which causes the water contained in the herbal residue to become subcritical, and the subcritical water temporarily decomposes the components contained in the herbal residue, such as cellulose, hemicellulose, and lignin.

[0014] The herbal medicine residue, which is pushed out by the piston 30A and temporarily decomposed, cools down and solidifies as it moves toward the outlet 40 formed at the end of the molding cylinder 30B, thereby becoming a solid fuel with high compressive strength.

[0015] <Drying process and drying means> The drying step is a step of drying the herbal residue so that its moisture content is between 3% and 10% by mass, and can be carried out by a drying means. By keeping the moisture content of the herbal residue within this range, an appropriate amount of water can be brought into a subcritical state, resulting in decomposition and high strength. If the moisture content is less than 3% by mass, the amount of water used may be insufficient, and the decomposition effect due to the subcritical state described above may not be achieved. If the moisture content exceeds 10% by mass, excess moisture may cause a decrease in compressive strength.

[0016] The drying means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include an electric heater. The drying temperature is not particularly limited and can be appropriately selected depending on the purpose, and can be, for example, 110° C. or higher and 200° C. or lower. The drying temperature refers to the surface temperature of the drying means.

[0017] <Pushing process and pushing means> The thrusting step is not particularly limited and can be appropriately selected depending on the purpose. For example, the crude drug residue can be thrusted using a piston and a molding cylinder at a pressure of 100 MPa or more.

[0018] The pressure of the piston in the thrusting step is 100 MPa or more, preferably 100 MPa or more and 250 MPa or less, and more preferably 200 MPa or more and 250 MPa or less. In the pushing process, the herbal residue is pushed with a pressure of 100 MPa or more, generating impact heat and frictional heat within the forming cylinder. This pressure brings the moisture contained in the herbal residue into a subcritical state, and the subcritical moisture temporarily decomposes the cellulose, hemicellulose, lignin, and other components contained in the herbal residue, which then solidifies, resulting in a solid fuel with higher compressive strength.

[0019] The diameter of the molding cylinder is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 40 mm to 120 mm, more preferably 60 mm to 120 mm, even more preferably 70 mm to 100 mm, and particularly preferably 75 mm to 100 mm. With such a cylinder diameter, the impact heat and frictional heat generated in the thrusting step can be transmitted to the herbal residue present in the center of the molding cylinder and can decompose the herbal residue, so the produced solid fuel tends to have high compressive strength.

[0020] Furthermore, the pushing length of the molding cylinder is preferably 150 mm or more and 200 mm or less, and more preferably 160 mm or more and 180 mm or less. If the pushing length is within this range, frictional heat and impact heat generated in the pushing step tend to be generated efficiently. If the pushing length is less than 150 mm, it is difficult to obtain the desired impact heat and frictional heat, and if it exceeds 200 mm, the load on the equipment may become too great and it may not be suitable for continuous production.

[0021] Typically, the pushing step is a step of pushing the herbal residue using a molding cylinder having a diameter of 40 mm or more and 75 mm or less with a pushing length of 150 mm or more and 200 mm or less, and can be carried out by a pushing means.

[0022] The molding cylinder is not particularly limited in shape, material, etc., as long as it has a cylindrical shape, and can be appropriately selected depending on the purpose. The molding cylinder may have a partially tapered structure as required.

[0023] Furthermore, in the pushing step, the piston in the molding cylinder is preferably driven at a rotation speed of 300 rpm or higher, more preferably 300 rpm or higher but 350 rpm or lower. When the rotation speed is 300 rpm or higher, impact heat and frictional heat are efficiently generated when pushing the herbal residue, and the moisture contained in the herbal residue can be brought to a subcritical state. That is, in the pushing step, impact heat can be generated by not only pushing but also hitting the herbal residue, and the moisture can be more efficiently brought to a subcritical state. Here, the rotation speed of the piston refers to, for example, the rotation speed of the crank 50 shown in FIG. 2.

[0024] In the pushing step, it is preferable to heat the molding cylinder. The heating means at this time is not particularly limited as long as it can heat the molding cylinder to a desired temperature or higher, and can be appropriately selected depending on the purpose. The heating temperature is preferably 120°C or higher and 200°C or lower. This temperature range can promote decomposition, which occurs when the water contained in the herbal residue is brought into a subcritical state by impact heat and frictional heat. On the other hand, temperatures below 120°C tend to make it difficult to promote the transition to the subcritical state, resulting in a decrease in compressive strength, while temperatures above 200°C are undesirable because they can cause the herbal residue to gasify. The heating temperature refers to the temperature of the outer shell of the molding cylinder. In the thrusting step, for example, a heating means may be installed so as to cover the molding cylinder 30B shown in Figs. 1 and 2, and the herbal medicine residue inside the cylinder may be heated within the above temperature range.

[0025] <Crushing process and crushing means> The crushing step is a step of crushing the herbal drug residue, and it is preferable to crush the herbal drug residue so that the particle size of the herbal drug residue is 2 mm or less before the pushing step. The crushing step can be performed by a crushing means. By preliminarily setting the particle size of the herbal residue to 2 mm or less, the herbal residue can be compressed more densely in the subsequent pushing process, resulting in a solid fuel with higher compressive strength. In addition, the strength can be improved by suppressing incomplete decomposition of the herbal residue. From the viewpoint of improving compressive strength, it is preferable to adjust the particle size to the above-mentioned range, but the method for producing a solid fuel of the present invention can be applied even if the herbal residue is not crushed.

[0026] The crushing means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a cutter mill and a hammer mill.

[0027] <Slow-cooling process and slow-cooling means> The slow cooling step is a step of slowly cooling the herbal medicine residue, and can be performed by a slow cooling means. By slowly cooling the herbal medicine residue, the moldability when molding the herbal medicine residue into a solid fuel becomes good.

[0028] In the slow cooling step, it is preferable to slowly cool the herbal residue while supporting it with a support member that is in partial contact with the pressed herbal residue. The pressed herbal residue takes a shape that matches the shape of the piston, but if the container for slow cooling is in contact with most of the outer periphery of the pressed herbal residue, moisture in the herbal residue may accumulate on the outer periphery, resulting in molding defects. Therefore, by slowly cooling the herbal residue while supporting it with a support member that is in partial contact with the pressed herbal residue, moisture can be appropriately removed from the surface of the herbal residue that is exposed and not in contact with the support member, and molding defects caused by moisture accumulating on the outer periphery can be suppressed. In the slow cooling step, for example, a support member can be connected to the rear of the discharge port 40 shown in Fig. 2, and the herbal medicine residue after being pushed and pressed can be sent forward while being exposed to the outside air. In addition, the slow cooling step can also be performed by blowing an air current onto the solid fuel using a cooling fan or the like, or by blowing a water current onto the solid fuel using a water-cooled jacket or the like, thereby forcibly cooling the solid fuel.

[0029] There are no particular restrictions on the shape, number, arrangement, etc. of the support members as long as they allow the surface of the herbal medicine residue to be partially exposed, and they can be selected appropriately depending on the purpose, such as a method of sandwiching the herbal medicine residue with six round steel support members as shown in Figure 3, or a method of sandwiching the herbal medicine residue with two pairs of L-shaped steel support members as shown in Figure 4. When such support members are used, the surface of the herbal medicine residue comes into contact with the outside air from two or more directions, making it easier for excess moisture to escape to the outside.

[0030] In the slow cooling step, the herbal medicine residue is preferably cooled slowly to a temperature of 80° C. or less, more preferably to a temperature of 50° C. or less. By slowly cooling the herbal medicine residue to a temperature of 80° C. or less, the moldability of the herbal medicine residue when it is molded into a solid fuel is improved.

[0031] In the slow cooling step, the herbal residue is preferably cooled at a rate of 3°C / min to 20°C / min, more preferably 3°C / min to 5°C / min. By cooling at a rate of 3°C / min to 20°C / min, moisture can be easily removed to a state suitable for use as a solid fuel.

[0032] In the slow cooling step, it is more preferable that the herbal residue be clamped with at least two support members from the outer periphery to the center at a pressure of 200 N to 500 N per 800 mm length. Clamping the herbal residue with a pressure of 200 N or more ensures good longitudinal mobility even when producing solid fuel continuously, while clamping the herbal residue with a pressure of 500 N or less allows the herbal residue to be solidified without deformation and allows excess moisture to be efficiently removed. The length means the length of the solid fuel in a direction parallel to the direction in which the herbal medicine residue is pushed.

[0033] <Herbal medicine residue> The herbal drug residue refers to the residue remaining after extracting herbal drug components from herbal medicines, and in one embodiment of the present invention, it is preferably a herbal drug residue.

[0034] The herbal medicine is not particularly limited and can be appropriately selected depending on the purpose. Examples include: apricot fruit, meadow saffron, Indian scutellaria, Coptis Rhizome, Phellodendron bark, Pueraria lobata, Calabar bean, licorice, cinchona, curare tree, cinnamon bark, coca tree, Bupleurum Root, Salvia officinalis, Dioscorea Root, digitalis, peony, ginger, strophanthus, Cnidium rhizome, Atractylodes rhizome, Chinese ginseng, ginseng root, carrot, mint, Pinellia Root, Atractylodes Root, Poria Coccinea, Peony Root, Boehmia Root, Ephedra, Artemisia Root, Artemisia japonica, Scopolia, belladonna, tea, cacao, coffee tree, camphor tree, and ergot fungus.

[0035] The components of the herbal drug residue are not particularly limited and can be appropriately selected depending on the purpose, and may include, for example, herbaceous roots, herbaceous stems, and calcium carbonate as the remainder. Examples of the herbaceous drug residue include those containing 60% to 80% by mass of herbaceous roots, 0% to 20% by mass of herbaceous stems, and 1% to 20% by mass of calcium carbonate. The herbal residue preferably contains calcium carbonate, which can improve the strength of the solid fuel. The content of calcium carbonate is preferably 20% by mass or less based on the total amount of the herbal residue.

[0036] (solid fuel) The solid fuel obtained by the above-described method for producing a solid fuel of the present invention has an apparent specific gravity of 1.05 or more and 1.30 or less, and a compressive strength of 10 MPa or more and 40 MPa or less. The solid fuel can be produced by the solid fuel production method and the solid fuel production apparatus of the present invention.

[0037] The method for measuring the apparent specific gravity is not particularly limited and can be appropriately selected depending on the purpose. For example, the apparent specific gravity can be measured using a liquid immersion method. Specifically, prepare a measuring cylinder filled with liquid and pour the solid fuel into the measuring cylinder. The calculation is performed based on the increased liquid volume and liquid specific gravity.

[0038] The method for measuring the compressive strength is not particularly limited and can be appropriately selected depending on the purpose. For example, the compressive strength can be measured using a compressive strength tester or a universal testing machine. Specifically, a metal jig for pressure is attached to a compression tester or a universal testing machine, and a load (N) is applied to the solid fuel to measure the maximum load (N) at which it collapses. The obtained results and the contact area (m 2 ) to obtain the compressive strength. [Explanation of symbols]

[0039] 10 Inlet 20 screws 30A Piston 30B molding cylinder 40 Outlet 50 crank 60 Support member 70 Herbal medicine residue 100 Solid fuel manufacturing equipment

Claims

1. A method for producing solid fuel from herbal residue, comprising: A crushing step of crushing the herbal medicine residue; a drying step of drying the herbal medicine residue so that the moisture content of the herbal medicine residue is 3% by mass or more and 10% by mass or less; a pushing step of pushing the herbal medicine residue at a pressure of 100 MPa or more using a molding cylinder equipped with a piston; A method for producing solid fuel, comprising:

2. The method for producing a solid fuel according to claim 1 , wherein the crushing step crushes the herbal residue so that the particle size of the herbal residue becomes 2 mm or less.

3. The method for producing a solid fuel according to claim 1 or 2, wherein the herbal residue contains at least one of herbaceous roots and herbaceous stems.

4. 3. The method for producing a solid fuel according to claim 1, further comprising, after the pushing step, a slow cooling step of slowly cooling the herbal residue while supporting the herbal residue with a support member that is in partial contact with the pushed herbal residue.

5. The method for producing a solid fuel according to claim 4, wherein the slow cooling step involves slow cooling the herbal residue to a temperature of 80°C or less.

6. The method for producing a solid fuel according to claim 4, wherein the slow cooling step involves slowly cooling the herbal residue at a temperature drop rate of 3°C / min or more and 20°C / min or less.

7. 5. The method for producing a solid fuel according to claim 4, wherein in the slow cooling step, the herbal residue is clamped by at least two support members from the outer periphery to the center of the herbal residue at a pressure of 200 N or more and 500 N or less per 800 mm length.

8. 3. The method for producing a solid fuel according to claim 1, wherein the pushing step uses a molding cylinder having a diameter of 40 mm or more and 120 mm or less, and pushes the herbal residue with a pushing length of 150 mm or more and 200 mm or less.

9. 3. The method for producing a solid fuel according to claim 1, wherein the piston in the molding cylinder is driven at a rotation speed of 300 rpm or more in the pushing step.

10. The method for producing a solid fuel according to claim 1 or 2, wherein the molding cylinder is heated to 120°C or higher and 200°C or lower in the pushing step.

11. A solid fuel manufacturing device characterized by having a thrusting means capable of thrusting herbal medicine residue inside a molding cylinder at a pressure of 100 MPa or more.

12. 12. The apparatus for producing a solid fuel according to claim 11, wherein the molding cylinder has a diameter of 40 mm to 120 mm and a pushing length of 150 mm to 200 mm.

13. 13. The apparatus for producing a solid fuel according to claim 11, further comprising a crushing means for crushing the herbal medicine residue to a particle size of 2 mm or less.

14. 13. The apparatus for producing a solid fuel according to claim 11, further comprising a drying means for drying the herbal medicine residue so that the moisture content of the herbal medicine residue becomes 10% by mass or less.

15. A solid fuel obtained by the method for producing a solid fuel according to any one of claims 1 and 2, A solid fuel characterized by an apparent specific gravity of 1.05 or more and 1.30 or less and a compressive strength of 10 MPa or more and 40 MPa or less.

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