Biomass solid fuel production equipment

Abstract

To provide a biomass solid fuel production facility capable of producing biomass solid fuel from which an organic component is hardly eluted.SOLUTION: A biomass solid fuel production device 100 comprises: a preheater 11 preheating pellets; a heat source for the preheating; a reactor 12 semi-carbonizing the pellets preheated by the preheater 11; a circulation channel L2 connecting a gas discharge port G2 and a gas introduction port G1 of the reactor 12, for semi-carbonization gas generated when the pellets are semi-carbonized in the reactor 12, to circulate therein; a branch channel L3 branched from the circulation channel L2, for the semi-carbonization gas to flow therethrough; a burner 15 burning semi-carbonization gas introduced thereinto; a first heat exchanger 14 disposed in the circulation channel L2; and a first combustion gas channel L41 connecting the burner 15 and the first heat exchanger 14, for the combustion gas generated in the burner 15 to flow therethrough, wherein the first heat exchanger 14 exchanges heat of the combustion gas generated in the burner 15 with the semi-carbonization gas circulating in the circulation channel L2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a manufacturing facility for biomass solid fuel.

Background Art

[0002] Coal-fired power generation has a high CO2 emission per emission unit and a high environmental load. To reduce CO2 emissions from coal-fired power generation, biomass co-firing in which biomass is mixed with coal for combustion has attracted attention. Co-firing of wood chips and wood pellets has already been carried out. However, since biomass has poorer grindability than coal, the maximum co-firing rate of biomass is only about several percent. Therefore, as one of the means to increase the biomass co-firing rate, a method of semi-carbonizing biomass can be mentioned. By semi-carbonizing biomass, a solid fuel with improved grindability can be obtained. In addition, the co-firing rate with coal can also be increased. For example, Patent Document 1 discloses a method for producing a solid fuel, characterized in that a woody biomass pulverized product having a size of 5 to 60 mm is densified to a bulk density (measured according to 6 "Bulk Density Test Method" of JIS K 2151) of 0.5 g / cm 3 or more, and then roasted under the conditions of an oxygen concentration of 10% or less and a temperature of 170 to 350 °C. For example, Patent Document 2 discloses a biomass solid fuel obtained by molding biomass powder, characterized in that the fuel ratio (fixed carbon / volatile matter) is 0.2 to 0.8, the higher heating value on an anhydrous basis is 4800 to 7000 (kcal / kg), the molar ratio of oxygen O to carbon C is 0.1 to 0.7, and the molar ratio of hydrogen H to carbon C is 0.8 to 1.3.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, when considering solid fuels such as wood pellets, for example, since solid fuels disintegrate when wet with water, they need to be stored in a silo or the like. However, since solid fuels obtained by semi-carbonizing biomass (hereinafter sometimes referred to as "black pellets") are hydrophobic, they can be stored outdoors, resulting in advantages such as not requiring facilities such as silos. However, when black pellets are stored outdoors, there is a concern about the elution of organic components (for example, COD components). While coal hardly elutes organic components, since black pellets elute organic components, there is a concern about the impact on the environment when stored outdoors. Therefore, when storing black pellets outdoors, it is necessary to suppress the elution of organic components as much as possible. For this purpose, manufacturing equipment capable of manufacturing black pellets having a structure in which organic components are hardly eluted is required.

[0005] An object of the present invention is to provide manufacturing equipment for biomass solid fuel capable of manufacturing biomass solid fuel in which organic components are hardly eluted.

Means for Solving the Problems

[0006] According to one aspect of the present invention, there is provided manufacturing equipment for biomass solid fuel that semi-carbonizes pellets containing biomass to produce biomass solid fuel, A preheater for preheating the pellets, a heat source for the preheating, a reactor for semi-carbonizing the pellets preheated by the preheater, a circulation flow path connecting the gas discharge port and the gas inlet port of the reactor, through which the semi-carbonization gas generated when the pellets are semi-carbonized in the reactor circulates, a branch flow path branched from the circulation flow path through which the semi-carbonization gas flows, a combustor into which the semi-carbonization gas flowing through the branch flow path is introduced and burned, a first heat exchanger disposed in the circulation flow path, and a first combustion gas flow path connecting the combustor and the first heat exchanger through which the combustion gas generated in the combustor flows. The first heat exchanger exchanges heat of the combustion gas generated in the combustor with the semi-carbonization gas circulating in the circulation flow path. A biomass solid fuel production facility is provided.

[0007] In the biomass solid fuel production facility according to one aspect of the present invention, a heat generation unit connected to the preheater and generating heating gas, and a heating gas introduction path for introducing the heating gas generated by the heat generation unit into the preheater are provided. It is preferable that the heating gas is the heat source for the preheating.

[0008] In the biomass solid fuel production facility according to one aspect of the present invention, it is preferable that the heat generation unit is a heater and generates the heating gas by heating the gas to be heated.

[0009] In the biomass solid fuel production facility according to one aspect of the present invention, a second combustion gas flow path connecting the first heat exchanger and the heat generation unit and through which the combustion gas heat-exchanged in the first heat exchanger flows is provided. It is preferable that the heat generation unit generates the heating gas by heating the gas to be heated by using the heat of the combustion gas flowing through the second combustion gas flow path.

[0010] In the biomass solid fuel production facility according to one aspect of the present invention, it is preferable that the heating gas is generated by heating the gas to be heated by using the heat of the combustion gas.

[0011] In the manufacturing equipment for biomass solid fuel according to one aspect of the present invention, a third combustion gas flow path connecting the first heat exchanger and the preheater is provided, and the combustion gas heat-exchanged in the first heat exchanger flows through the third combustion gas flow path and is introduced into the preheater. It is preferable that the combustion gas heat-exchanged in the first heat exchanger is the heat source for the preheating.

[0012] In the manufacturing equipment for biomass solid fuel according to one aspect of the present invention, it is preferable to provide a fine powder separation device for separating fine powder contained in the semi-carbonized gas generated in the reactor between the gas discharge port of the reactor and the first heat exchanger.

Effects of the Invention

[0013] According to one aspect of the present invention, it is possible to provide manufacturing equipment for biomass solid fuel capable of manufacturing biomass solid fuel in which organic components are hardly eluted.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0015] In this specification, the numerical range represented by "~" means a range including the numerical value described before "~" as the lower limit value and the numerical value described after "~" as the upper limit value. In this specification, the expressions using ordinal numbers such as "first", "second", and "third" are for the purpose of distinguishing members and do not mean order.

[0016] 〔First Embodiment〕 A biomass solid fuel manufacturing facility according to the first embodiment (which may be simply referred to as the manufacturing facility) will be described with reference to the drawings.

[0017] <Overall Configuration> FIG. 1 is a schematic diagram showing one aspect of the manufacturing facility according to the first embodiment. In FIG. 1, white pellets refer to biomass pellets that have not been semi-carbonized. In FIG. 1, L11 indicates the path of the white pellets, and L12 indicates the path of the biomass solid fuel (black pellets). The manufacturing facility 100 shown in FIG. 1 is a facility for manufacturing biomass solid fuel by semi-carbonizing pellets containing biomass (white pellets in FIG. 1). In the first embodiment, a case will be described where the heat source (heat source for preheating) when preheating the pellets with the preheater 11 is the heating gas generated by the heat generation unit 16X. The manufacturing facility 100 includes a preheater 11 for preheating the pellets, a reactor 12 for semi-carbonizing the preheated pellets, a circulation flow path L2 that connects the gas discharge port G2 and the gas inlet G1 of the reactor 12 and through which the semi-carbonization gas generated when semi-carbonizing the pellets in the reactor 12 circulates, a branch flow path L3 that branches from the circulation flow path L2 and through which the semi-carbonization gas flows, a combustor 15 into which the semi-carbonization gas flowing through the branch flow path L3 is introduced and which burns the semi-carbonization gas, a fine powder separator 13 disposed in the circulation flow path L2, a first heat exchanger 14 disposed in the circulation flow path L2, a first combustion gas flow path L41 that connects the combustor 15 and the first heat exchanger 14 and through which the combustion gas generated by the combustor 15 flows, a heat generation unit 16X that generates heating gas (heat source for preheating), and a heating gas introduction path L5 that introduces the heating gas generated by the heat generation unit 16X into the preheater 11. The first heat exchanger 14 exchanges heat between the heat of the combustion gas generated in the combustor 15 and the semi-carbonized gas circulating in the circulation flow path L2. The manufacturing facility 100 also includes a conveyor 16 for transporting the black pellets manufactured in the reactor 12 and a sieve 17.

[0018] <Pre-heater 11> The pre-heater 11 pre-heats the pellets. Pre-heating means pre-heating the pellets at a temperature (for example, 30°C or higher and 100°C or lower) such that the pellets do not semi-carbonize before being introduced into the reactor 12. The temperature of the pre-heating is controlled by, for example, temperature control means (not shown). In the case of FIG. 1, the heat source for the pre-heating is the heating gas generated in the heat generation unit 16X. The heat generation unit 16X generates the heating gas by heating the gas to be heated.

[0019] <Reactor 12> The reactor 12 semi-carbonizes the pellets pre-heated in the pre-heater 11. Semi-carbonization refers to a state in which at least a part of the biomass is carbonized. Therefore, semi-carbonization in this specification includes a state in which a part of the biomass is carbonized and a state in which all of the biomass is carbonized. The semi-carbonized pellets (black pellets) can be obtained by heating the white pellets at, for example, 200°C or higher and 300°C or lower. The temperature of the semi-carbonization is controlled by, for example, temperature control means (not shown).

[0020] <Fine powder separator 13> The fine powder separator 13 is disposed between the gas discharge port G2 of the reactor 12 and the first heat exchanger 14, and separates the fine powder contained in the semi-carbonized gas generated in the reactor 12. The fine powder separator 13 is not particularly limited, and examples include a cyclone, a screen, and a bag filter.

[0021] <First heat exchanger 14> The first heat exchanger 14 exchanges heat (heat transfer) between the heat of the combustion gas generated in the combustor 15 and the semi-carbonized gas circulating in the circulation flow path L2.

[0022] <Combustor 15> The combustor 15 burns the semi-carbonized gas introduced from the branch flow path L3. In the case of FIG. 1, into the combustor 15, the semi-carbonized gas flowing through the branch flow path L3 and the fuel air from the path L Air are introduced. The combustor 15 burns the semi-carbonized gas together with the fuel air introduced from the path L Air .

[0023] <Heat generation unit 16X> The heat generation unit 16X is connected to the preheater 11 and generates a heating gas (heat source for preheating). In the case of FIG. 1, the heat generation unit 16X generates a heating gas by heating the gas to be heated. The heating gas generated by the heat generation unit 16X is introduced into the preheater 11 via the heating gas introduction path L5. The heat generation unit 16X is not particularly limited, but usually a heater is used. Examples of the heater include a heating furnace and a heat exchanger. The gas to be heated is not particularly limited, but examples include at least one selected from air and an inert gas (e.g., nitrogen). From the viewpoint of effectively utilizing energy, it is preferable to use the gas generated in the manufacturing facility 100 for generating the heating gas. Examples of the gas generated in the manufacturing facility 100 include the semi-carbonized gas generated in the reactor 12 and the combustion gas generated in the combustor 15.

[0024] <Function> In the manufacturing facility 100 of the first embodiment, the biomass solid fuel (black pellet) is manufactured as follows. Pellets (white pellets) are introduced into the preheater 11. Also, the heating gas generated by the heat generation unit 16X is introduced into the preheater 11 from the heating gas introduction path L5. In the preheater 11, the pellets are preheated using the heating gas as a heat source. The preheated pellets are discharged from the preheater 11 and introduced into the reactor 12. Inside the reactor 12, the pellets are semi-carbonized at a predetermined temperature to become black pellets. The semi-carbonized gas generated in the reactor 12 is discharged from the gas outlet G2, and after the fine powder is removed by the fine powder separator 13, it is introduced into the first heat exchanger 14. On the other hand, into the combustor 15, the semi-carbonized gas flowing through the branch flow path L3 and the combustion air from the path L Air are introduced. In the combustor 15, the semi-carbonized gas is burned together with the combustion air. The combustion gas generated in the combustor 15 is introduced into the first heat exchanger 14 through the first combustion gas flow path L41. In the first heat exchanger 14, the heat of the combustion gas is heat-exchanged (heat transfer) to the semi-carbonized gas. The heat-exchanged semi-carbonized gas flows through the circulation flow path L2, a part of which is branched into the branch flow path L3 and introduced into the combustor 15, and the rest is introduced into the reactor 12 from the gas inlet G1 of the reactor 12. The combustion gas that has undergone heat exchange to the semi-carbonized gas is then discharged into the atmosphere. The black pellets produced in the reactor 12 are transported by the conveyor 16 through the path L12 and subjected to a sieve 17.

[0025] <Effect> According to the manufacturing facility 100 of the first embodiment, black pellets can be manufactured while effectively utilizing the energy generated in the manufacturing facility 100. Further, in the manufacturing facility 100, since the pellets preheated by the preheater 11 are introduced into the reactor 12, it is possible to suppress the adsorption of moisture on the pellet surface immediately after the pellets are introduced into the reactor 12. As a result, surface deterioration is suppressed, and black pellets in which organic components are hardly eluted can be obtained. This is presumably because the components presumably derived from lignin coating the pellets become less soluble due to preheating. In addition, since the manufactured black pellets are hydrophobic, they can be stored outdoors.

[0026] 〔Second Embodiment〕 Regarding the second embodiment, the description will focus on the differences from the first embodiment, and for the description of the same matters, the description will be omitted or simplified by attaching the same reference numerals etc.

[0027] <Overall Configuration> FIG. 2 is a schematic diagram showing an aspect of the manufacturing equipment according to the second embodiment. In the second embodiment, the case where the heat source when preheating the pellets with the preheater 11 is the drying air (an example of a heating gas) directly heated by the heater 16A will be described. The manufacturing equipment 200 shown in FIG. 2 includes a heater 16A as a heat generation unit. In the case of FIG. 2, the heater 16A is a heating furnace. The manufacturing equipment 200 shown in the second embodiment is different from the first embodiment in that it includes a heater 16A as a heat generation unit. Other points are the same as those in the first embodiment.

[0028] <Operation> In the manufacturing equipment 200 of the second embodiment, the biomass solid fuel (black pellets) is manufactured as follows. The description will focus on the differences from the first embodiment. The heater 16A (a heating furnace in the case of FIG. 2) generates a heating gas by directly heating the drying air as the gas to be heated. The generated heating gas is introduced into the preheater 11 through the heating gas introduction path L5. The pellets in the preheater 11 are preheated using this heating gas as a heat source.

[0029] <Effect> According to the manufacturing equipment 200 of the second embodiment, black pellets in which organic components are difficult to elute can be manufactured.

[0030] 〔Third Embodiment〕 Regarding the third embodiment, the description will focus on the differences from the first embodiment, and for the description of the same matters, the description will be omitted or simplified by attaching the same reference numerals etc.

[0031] <Overall Configuration> FIG. 3 is a schematic diagram showing an aspect of the manufacturing equipment according to the third embodiment. In the third embodiment, a case where the heat source for preheating the pellets with the preheater 11 is the heat-exchanged drying air (an example of a heating gas) will be described. The manufacturing facility 300 shown in FIG. 3 includes a heater 16B as a heat generation unit, and a second combustion gas flow path L42 that connects the first heat exchanger 14 and the heater 16B. The combustion gas heat-exchanged in the first heat exchanger 14 flows through the second combustion gas flow path L42. In the case of FIG. 3, the heater 16B is a second heat exchanger. The manufacturing facility 300 shown in the third embodiment differs from the first embodiment in that it includes a heater 16B as a heat generation unit and a second combustion gas flow path L42. Other points are the same as those in the first embodiment.

[0032] <Operation> In the manufacturing facility 300 of the third embodiment, biomass solid fuel (black pellets) is manufactured as follows. The description will focus on the differences from the first embodiment. The combustion gas heat-exchanged in the first heat exchanger 14 flows through the second combustion gas flow path L42 and is introduced into the heater 16B (in the case of FIG. 3, the second heat exchanger). The heater 16B generates a heating gas by heat-exchanging (transferring heat) the heat of the combustion gas (in the case of FIG. 3, the heat of the combustion gas heat-exchanged in the first heat exchanger 14) to the drying air as the gas to be heated. The generated heating gas is introduced into the preheater 11 through the heating gas introduction path L5. The pellets in the preheater 11 are preheated using this heating gas as a heat source. <Effect> According to the manufacturing facility 300 of the third embodiment, it is possible to manufacture black pellets in which organic components are difficult to elute while effectively using the energy generated in the manufacturing facility 300.

[0033] 〔Fourth Embodiment〕 Regarding the fourth embodiment, the description will focus on the differences from the third embodiment, and the description of the same matters will be omitted or simplified by assigning the same reference numerals.

[0034] <Overall Configuration> FIG. 4 is a schematic diagram showing an aspect of the manufacturing facility according to the fourth embodiment. In the fourth embodiment, a case where the heat source (heat source for preheating) when preheating the pellets with the preheater 11 is combustion gas (combustion gas heat-exchanged in the first heat exchanger 14 in the case of FIG. 4) will be described. The manufacturing facility 400 shown in FIG. 4 includes a third combustion gas flow path L43 that connects the first heat exchanger 14 and the preheater 11. The third combustion gas flow path L43 allows the combustion gas heat-exchanged in the first heat exchanger 14 to flow through. That is, the manufacturing facility 400 shown in the fourth embodiment is different from the third embodiment in that the combustion gas heat-exchanged in the first heat exchanger 14 is directly introduced into the preheater 11. Other points are the same as those in the third embodiment.

[0035] <Operation> In the manufacturing facility 400 of the fourth embodiment, biomass solid fuel (black pellets) is manufactured as follows. The description will focus on the points different from the third embodiment. The combustion gas heat-exchanged in the first heat exchanger 14 flows through the third combustion gas flow path L43 and is directly introduced into the preheater 11. The pellets in the preheater 11 are preheated using the combustion gas directly introduced into the preheater 11 as a heat source. <Effect> According to the manufacturing facility 400 of the fourth embodiment, black pellets in which organic components are difficult to elute can be manufactured. Further, when the manufacturing facility 400 of the fourth embodiment is used, it is possible to eliminate the need for installing a heater. However, since the combustion gas heat-exchanged in the first heat exchanger 14 is high-temperature and contains air (oxygen), it is desirable to adjust the flow rate and temperature of the combustion gas when introducing the combustion gas into the preheater 11.

[0036] 〔Other Embodiments〕 In the third embodiment, an example in which one second heat exchanger is used as the heater 16B to exchange the heat of the combustion gas with the drying air has been described, but the present invention is not limited to this. For example, a plurality of heat exchangers may be used to exchange the heat of the combustion gas with the drying air step by step. In the third embodiment, for example, the combustion gas generated in the combustor 15 may be directly introduced into the second heat exchanger without passing through the first heat exchanger 14. In this case, the heat of the combustion gas generated in the combustor 15 is exchanged with the drying air. In the fourth embodiment, for example, the combustion gas generated in the combustor 15 may be directly introduced into the preheater 11 without passing through the first heat exchanger 14. In this case, the combustion gas generated in the combustor 15 is used as a heat source for preheating the pellets.

Industrial Applicability

[0037] The manufacturing facility for biomass solid fuel of the present invention can be installed and used in power plants, steel mills, and factories that perform biomass power generation and co-firing power generation of biomass and coal.

Explanation of Symbols

[0038] 11…Preheater, 12…Reactor, 13…Fine powder separator, 14…First heat exchanger, 15…Combustor, 16…Conveyor, 16X…Heat generation section, 16A, 16B…Heater, 17…Sieve, 100, 200, 300, 400…Manufacturing facility.

Claims

1. A manufacturing facility for biomass solid fuel that produces biomass solid fuel by semi-carbonizing pellets containing biomass, comprising: A pre-heater for pre-heating the pellets; A heat source for the pre-heating; A reactor for semi-carbonizing the pellets pre-heated by the pre-heater; A circulation flow path that connects the gas discharge port and the gas inlet port of the reactor and through which the semi-carbonization gas generated when the pellets are semi-carbonized in the reactor circulates; A branch flow path branched from the circulation flow path through which the semi-carbonization gas flows; A combustor into which the semi-carbonization gas flowing through the branch flow path is introduced and which burns the semi-carbonization gas; A first heat exchanger disposed in the circulation flow path; A first combustion gas flow path that connects the combustor and the first heat exchanger and through which the combustion gas generated by the combustor flows; A heat generation unit connected to the pre-heater that generates heated gas by heating a gas to be heated using the heat of the combustion gas generated by the combustor; A heated gas introduction path for introducing the heated gas generated by the heat generation unit into the pre-heater, and comprising: The first heat exchanger exchanges the heat of the combustion gas generated by the combustor with the semi-carbonization gas circulating in the circulation flow path; The heated gas is the heat source for the pre-heating; The heat generation unit is a heater; A manufacturing facility for biomass solid fuel.

2. In the manufacturing facility for biomass solid fuel according to Claim 1, A second combustion gas flow path is provided that connects the first heat exchanger and the heat generation unit and through which the combustion gas heat-exchanged by the first heat exchanger flows; The heat generation unit generates the heated gas by heating a gas to be heated using the heat of the combustion gas flowing through the second combustion gas flow path; A manufacturing facility for biomass solid fuel.

3. In the manufacturing facility for biomass solid fuel according to Claim 1 or Claim 2, A fine powder separation device for separating fine powder contained in the semi-carbonization gas generated in the reactor is provided between the gas discharge port of the reactor and the first heat exchanger; A manufacturing facility for biomass solid fuel.

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