Black pellets and method for producing the same

Abstract

To provide a technique of producing fuel using a biomass material.SOLUTION: A black pellet and a method for producing the same are disclosed. In one embodiment, a method for producing a black pellet includes a compression step of compressing a biomass material, a volatile component removal step of removing a volatile component from the compressed material compressed in the compression step, a semi-carbonization step of semi-carbonizing the raw material from which the volatile component has been removed in the volatile component removal step, a crushing step of crushing the semi-carbonized material processed in the semi-carbonization step, a mixing step of adding a combustion aid and a binder to the crushed material processed in the crushing step and mixing them, and a pelletizing step of making the mixture produced in the mixing step into pellets.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to black pellets and a method for manufacturing the same.

Background Art

[0002] Since the Paris Climate Agreement in 2015, worldwide efforts have continued to limit the rise in the earth's average temperature. As part of such efforts, there is a movement to reduce the use of fossil fuels, which are one of the causes of global warming, and to use new renewable energy.

[0003] New renewable energy refers to energy that is obtained by converting existing fossil fuels or by converting renewable energy such as sunlight, water, geothermal heat, rainwater, and biological organisms. Unlike fossil fuels, new renewable energy is characterized by being renewable and non-depleting, emitting few pollutants and carbon dioxide, being environmentally friendly, and being relatively evenly distributed on the earth compared to fossil fuels.

[0004] Among new renewable energies, forest biomass is a carbon-neutral energy and is known as an environmentally friendly renewable energy that minimizes climate change and substitutes for fossil fuels. For example, wood pellets are obtained by making large sawdust from wood remaining after logging or forestry by-products not contaminated by chemicals such as preservatives and paints, and then compressing and processing them to a certain size. In this regard, Korean Registered Patent Publication No. 10-0878051 discloses a technique for a method of manufacturing wood pellets.

[0005] On the other hand, palm empty fruit bunches (EFB) refer to the residues remaining after removing the fruit bunches of palm fruits to produce palm oil and the like from palm fruits. Such palm waste, palm empty fruit bunches, has been partially used as livestock feed or compost, but the unused portion had to be incinerated or discarded.

[0006] By the way, palm empty fruit bunches are prone to spoilage due to their high water content. If palm empty fruit bunches spoil, there is a problem that methane gas, which is one of the greenhouse gases, is generated. However, due to various current regulations, it is difficult to incinerate palm empty fruit bunches, and there is a situation where a great deal of cost is incurred during waste treatment. Therefore, from the perspectives of resource recycling and the environment, the development of technologies that can utilize discarded by-products as fuel is an urgent situation.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] The technical idea of the present invention is for solving the above-described problems, and its object is to provide a technology for manufacturing fuel using biomass raw materials.

[0009] Furthermore, the technical idea of the present invention has a further object of providing a technology for recycling by-products that were conventionally incinerated or discarded as fuel.

[0010] The problems to be solved by the present invention are not limited to the above-described problems, and other technical problems not mentioned will be clearly understandable to those having ordinary knowledge in the technical field to which the present invention pertains from the content described later.

Means for Solving the Problems

[0011] To achieve such an object, as an embodiment of the present invention, a method for manufacturing black pellets includes a pressing step of pressing biomass raw materials, a volatile component removing step of removing volatile components from the pressed material pressed in the pressing step, a semi-carbonization step of semi-carbonizing the raw material from which the volatile components have been removed in the volatile component removing step, a pulverizing step of pulverizing the semi-carbonized material semi-carbonized in the semi-carbonization step, a mixing step of adding a combustion additive and a binder to the pulverized material pulverized in the pulverizing step and mixing them, and a pelletizing step of forming the mixture mixed in the mixing step into pellets.

[0012] In the volatile component removing step, an inert gas is injected into the chamber in which the pressed material is disposed, the pressed material is heat-treated at 200 to 300°C in a state where oxygen present in the chamber is removed, and the volatile components emitted from the pressed material can be discharged to the outside of the chamber.

[0013] The biomass raw material can be at least one selected from wood by-products, palm empty fruit bunches (EFB), and palm kernel shells (PKS).

[0014] The combustion additive is aluminosilicate, and the ratio of the content of silicon dioxide contained in the aluminosilicate to the content of aluminum oxide contained in the aluminosilicate can be 0.65 to 1.85.

[0015] To achieve the above object, as another embodiment of the present invention, the black pellets can be manufactured by the method for manufacturing black pellets described above.

[0016] To achieve the above object, as still another embodiment of the present invention, the black pellets can include a semi-carbonized material obtained by semi-carbonizing palm empty fruit bunches and aluminosilicate mixed with the semi-carbonized material.

[0017] The ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate can be 0.65 to 1.85.

[0018] The calorific value of the black pellet can be 5500 cal / g to 7000 cal / g.

[0019] The black pellet may have an atomic ratio of hydrogen to carbon of 0.8 to 1.6 and an atomic ratio of oxygen to carbon of 0.2 to 0.8.

[0020] The solutions to the above-mentioned problems are merely exemplary and should not be construed as an intention to limit the present invention. In addition to the above-mentioned exemplary embodiments, additional embodiments may exist as described in the drawings and the detailed description of the invention.

Advantages of the Invention

[0021] As described above, according to various embodiments of the present invention, by producing black pellets using biomass raw materials, it is possible to produce an environmentally friendly fuel with a high calorific value.

[0022] Also, the black pellets according to various embodiments of the present invention can be co-fired with coal in a coal-fired power plant and can also be utilized as a fuel in a steel mill.

[0023] And according to various embodiments of the present invention, during the combustion of the black pellet, the aluminosilicate, which is a combustion additive, can react with specific components (for example, potassium, sodium, chlorine, etc.) contained in the biomass raw material to produce a high-melting-point substance. Therefore, it is possible to improve the thermal imbalance inside the boiler, slagging and fouling phenomena, and corrosion problems caused by specific components present in the biomass raw material.

[0024] In particular, when manufacturing black pellets from palm empty fruit bunches, it is possible to reduce the costs associated with the waste treatment of palm empty fruit bunches, reduce the methane gas generated by the decay of palm empty fruit bunches, and when burning the black pellets, potassium, chlorine components, etc. contained in the palm empty fruit bunches are converted into high-melting-point substances by aluminosilicates, thus contributing to the complete combustion of the fuel and preventing in advance the corrosion of the metal surface including the inner wall of the boiler.

[0025] The effects according to various embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understandable to those skilled in the art from the description of the claims.

Brief Description of the Drawings

[0026]

Figure 1

Modes for Carrying Out the Invention

[0027] Preferred embodiments of the present invention will be described more specifically with reference to the accompanying drawings, but for known technical parts, for the sake of brevity of description, they will be omitted or compressed.

[0028] It should be noted that in this specification, references to "one" or "a" embodiment of the present invention are not necessarily to the same embodiment, and these mean at least one.

[0029] In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0030] In the following examples, terms such as "comprising" or "having" mean that the features or components described in the specification exist, and do not preclude in advance the possibility of adding one or more other features or components.

[0031] If other embodiments are feasible, the specific process order can also be carried out differently from the order of description. For example, two consecutive processes described can also be carried out substantially simultaneously or in an order opposite to the order of description. That is, each process of the method described in this specification can be appropriately implemented in any order as long as it is not otherwise mentioned in the specification or clearly contrary in context.

[0032] The term "black pellet" as used in this specification refers to pellets with a black color, which can be made black through a semi-carbonization process during pellet production.

[0033] The term "wood by-product" as used in this specification refers to products produced other than for the necessary uses during wood processing, and refers to by-products that inevitably occur during the process of wood processing. For example, wood by-products can be waste wood, large sawdust, or bark.

[0034] The method for manufacturing black pellets according to an embodiment of the present invention will be described with reference to FIG. 1 and will be described in order for convenience.

[0035] 1. Pressing process <s101>< / s101> In this step, the biomass raw material can be pressed. For example, in this step, the biomass raw material is put into a press and a certain pressure is applied to press the biomass raw material, thereby reducing the volume of the biomass raw material and increasing its density.

[0036] According to an embodiment, at least one selected from among wood by-products, palm empty fruit bunches, and palm kernel shells can be applied as the biomass raw material to be pressed in this step. The biomass raw material can be used alone or in combination of two or more.

[0037] 2. Volatile Component Removal Step <s102>< / s102> In this process, volatile components can be removed from the pressed material pressed in step S101. According to one embodiment, the pressed material is put into the chamber, and with the chamber sealed, the chamber control unit opens the inlet of the chamber for a certain period of time to inject an inert gas (for example, carbon dioxide), and opens the outlet of the chamber to let the gas in the chamber flow out to the outside of the chamber, thereby removing the oxygen present in the chamber.

[0038] Also, when the oxygen concentration in the chamber is below a preset value, the chamber control unit maintains the temperature inside the chamber at 200 - 300 °C to heat-treat the pressed material, and can discharge the volatile components emitted from the pressed material to the outside of the chamber. Here, the volatile components are components that can be removed from the pressed material while evaporating as a gas when the pressed material is heated to 200 °C or higher.

[0039] According to one embodiment, in this process, after the chamber control unit maintains the temperature inside the chamber at 200 - 300 °C for 10 - 15 minutes, it injects an inert gas into the inlet of the chamber and opens the outlet of the chamber, thereby discharging the volatile components remaining in the chamber to the outside of the chamber. After a certain period of time has passed since the volatile components were discharged from the chamber, the chamber control unit can close the outlet of the chamber.

[0040] 3. Semi-carbonization process <s103>< / s103> In this process, the raw material from which volatile components have been removed in step S102 can be semi-carbonized. For example, in this process, the chamber control unit can turn the raw material into semi-carbonized material by maintaining the temperature inside the chamber at 300 - 400 °C for 20 - 30 minutes with the inside of the chamber in an oxygen-free or low-oxygen atmosphere. Here, the oxygen-free atmosphere or low-oxygen atmosphere means a state where the oxygen concentration in the chamber is below a preset value (or a state of an inert atmosphere substantially free of oxygen) by supplying an inert gas into the chamber at a certain flow rate.

[0041] According to a specific example, the chamber control unit opens the inlet of the chamber for a certain period of time to inject an inert gas (for example, carbon dioxide), and opens the outlet of the chamber to let the gas in the chamber flow out to the outside of the chamber, thereby removing the oxygen present in the chamber and adjusting the oxygen concentration to be below a preset value. Only when the oxygen concentration is below the preset value, the temperature inside the chamber is maintained at 300 - 400 °C for 20 - 30 minutes, and the semi-carbonization process can be carried out.

[0042] 4. Crushing Process <s104>< / s104> In this step, the semi-carbonized product semi-carbonized in step S103 can be pulverized. For example, in this step, the semi-carbonized product can be put into a pulverizer and pulverized so that the semi-carbonized product becomes particles having a certain average particle size range (for example, 0.1 - 5 mm).

[0043] 5. Hybrid Engineering <s105>< / s105> In this step, a combustion additive and a binder can be added to and mixed with the pulverized product pulverized in step S104. In one embodiment, an aluminosilicate can be applied as the combustion additive. In this specification, aluminosilicate means a combination of alumina (Al2O3) and silica (SiO2). The aluminosilicate according to one embodiment can have a structure in which the number of silicon (Si) elements is 1 - 5 with respect to the aluminum (Al) element.

[0044] In one embodiment, the content of aluminosilicate can be 0.1 - 10 parts by weight (for example, 0.1 part by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight or 10 parts by weight) per 100 parts by weight of the pulverized product.

[0045] In this process, non-limiting examples of the binder to be introduced include myristic acid, palmitic acid, oleic acid, or castor oil, etc. According to one embodiment, the input amount of the binder can be 0.1 to 15 parts by weight (for example, 0.1 part by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, or 15 parts by weight) per 100 parts by weight of the pulverized material.

[0046] 6. Pelletization process <s106>< / s106> In this process, the mixture mixed in step S105 can be made into pellets. According to one embodiment, the mixture mixed in step S105 is put into a pelletizer to produce pellets with a diameter of 4 to 10 mm and a length of 50 to 70 mm. According to one specific example, the mixture put into the pelletizer is extruded to have a diameter of 4 to 10 mm, and the extrudate is cut to a certain length to produce pellets. Of course, the diameter and length of the pellets produced in this process can also be adjusted as needed.

[0047] <Explanation of black pellets according to one embodiment> The black pellets according to one embodiment are produced by mixing semi-carbide and aluminosilicate and pelletizing. The black pellets can include semi-carbide obtained by semi-carbonizing palm empty fruit bunches, and aluminosilicate mixed with the semi-carbide.

[0048] The aluminosilicate according to one embodiment can have a specific surface area of 100 to 180 m 2 / g as measured according to the provisions of ISO 9277:2010 of the International Organization for Standardization. As a specific example, the specific surface area of the aluminosilicate is 100 m 2 / g, 110 m 2 / g, 120 m 2 / g, 130 m 2 / g, 140 m 2 / g, 150 m 2 / g, 160 m 2 / g, 170 m 2 / g or 180 m2 / g can be applied. Also, the specific surface area of the aluminosilicate can be in the range of one or more of the above values and one or less of the above values.

[0049] For example, the specific surface area range of the aluminosilicate is 100 m 2 / g to 140 m 2 / g, 105 m 2 / g to 135 m 2 / g, 110 m 2 / g to 130 m 2 / g, 115 m 2 / g to 135 m 2 / g, 120 m 2 / g to 150 m 2 / g, 125 m 2 / g to 145 m 2 / g, 100 m 2 / g to 150 m 2 / g or 100 m 2 / g to 180 m 2 / g can be. The upper limit of the specific surface area of the aluminosilicate according to one embodiment is not particularly limited. For example, it can be 300 m 2 / g or less, 250 m 2 / g or less, 200 m 2 / g or less, 180 m 2 / g or less or 150 m 2 / g or less can be.

[0050] When producing black pellets using biomass raw materials such as wood by-products, palm empty fruit bunches, and palm kernel shells, due to the characteristics of the biomass raw materials, they can partially contain alkaline components (such as K, Na, K2O, Na2O, etc.) or chlorine (Cl).

[0051] When black pellets burn, the alkali components released from the biomass raw materials can cause slagging and fouling phenomena while adhering to the inner wall of the boiler, heat exchange parts, etc. The chlorine released from the biomass raw materials may react with the alkali components at high temperatures to form chlorides (such as KCl, NaCl, etc.) while corroding the metal inside the boiler. However, in one embodiment, by mixing aluminosilicate with the biomass raw materials to produce black pellets, it is possible to prevent the occurrence of slagging and fouling phenomena during the combustion of black pellets and improve the corrosion problem of the boiler.

[0052] According to one embodiment, the larger the specific surface area value of the aluminosilicate, the easier it is to adsorb the alkali components and chlorides generated during the combustion of black pellets, and the metal corrosion, slagging, and fouling phenomena can be effectively suppressed. When the specific surface area of the aluminosilicate is less than 100 m 2 / g, the efficiency of physically adsorbing and collecting the alkali components and chlorides generated during the combustion of black pellets decreases, so the slagging and fouling phenomena cannot be fully controlled, and there is a risk that chlorides will adhere to the inside of the boiler and corrode the metal parts.

[0053] And in one embodiment, the average particle size of the aluminosilicate can be applied in the range of 20 - 500 μm. As a specific example, the average particle size of the aluminosilicate can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm. Of course, depending on the implementation, it is also possible to adjust the average particle size of the aluminosilicate differently according to the combustion situation.

[0054] In one embodiment, the aluminosilicate can contain silicon dioxide and aluminum oxide. The aluminosilicate according to one embodiment can also contain inevitable impurities as the remaining amount excluding silicon dioxide and aluminum oxide.

[0055] According to one embodiment, the content of aluminum oxide contained in the aluminosilicate can be 20 to 60% by weight based on the total weight of the aluminosilicate. As specific examples, the content of aluminum oxide can be 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight or 60% by weight. Also, the content of aluminum oxide can be one or more of the above values and one or less of the above values.

[0056] For example, the content range of aluminum oxide contained in the aluminosilicate can be 20% by weight to 30% by weight, 30% by weight to 40% by weight, 35% by weight to 45% by weight, 40% by weight to 50% by weight or 20% by weight to 60% by weight. Aluminum oxide according to one embodiment can effectively control the alkali components and chlorides contained in the biomass raw material within the above range.

[0057] If the aluminum oxide contained in the aluminosilicate is outside the range of 20 to 60% by weight, it is not easy to effectively control the alkali components and chlorides released from the biomass raw material during the combustion of the black pellets.

[0058] In one embodiment, the content of silicon dioxide contained in the aluminosilicate can be 40 to 80% by weight based on the total weight of the aluminosilicate. As specific examples, the content of silicon dioxide can be 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight or 80% by weight. Also, the content of silicon dioxide can be one or more of the above values and one or less of the above values.

[0059] For example, the content range of silicon dioxide contained in aluminosilicate can be 40 wt% - 50 wt%, 50 wt% - 60 wt%, 55 wt% - 65 wt%, 60 wt% - 70 wt%, 55 wt% - 70 wt% or 40 wt% - 80 wt%. According to one embodiment, silicon dioxide can effectively control the alkali components and chlorides contained in the biomass raw material within the above range. If the silicon dioxide contained in aluminosilicate is outside the range of 40 - 80 wt%, it is not easy to effectively control the alkali components and chlorides released from the biomass raw material during the combustion of black pellets.

[0060] According to one embodiment, when the black pellet burns, the aluminosilicate chemically reacts with the alkali components and chlorides contained in the biomass raw material, so that the alkali components and chlorides released from the biomass raw material can be converted into at least one of calcilite (KAlSiO4) and leucite (KAlSi2O6).

[0061] That is, the alkali components and chlorides generated during the combustion of black pellets react with aluminosilicate and are converted into calcilite with a melting point of 1600 °C or higher or leucite with a melting point of 1500 °C or higher. Therefore, the problems of slagging, fouling, and condensation caused by the melting of alkali components in the boiler in the past can be improved, and the problem of metal corrosion caused by chlorides can be prevented.

[0062] On the other hand, according to one embodiment, the ratio of the content of silicon dioxide contained in aluminosilicate divided by the content of aluminum oxide contained in aluminosilicate can be 0.65 - 1.85. In a specific example, if the silicon dioxide contained in aluminosilicate is 48 parts by weight and the aluminum oxide contained in aluminosilicate is 42 parts by weight, the ratio of the content of silicon dioxide contained in aluminosilicate divided by the content of aluminum oxide contained in aluminosilicate can be 1.14.

[0063] As a specific example, the ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate may be 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.84, 0.86, 0.88, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.3, 1.31, 1.32, 1.34, 1.36, 1.38, 1.4, 1.42, 1.44, 1.46, 1.48, 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, 1.56, 1.57, 1.58, 1.59, 1.6, 1.61, 1.62, 1.63, 1.64, 1.65, 1.66, 1.67, 1.68, 1.69, 1.7, 1.71, 1.72, 1.73, 1.74, 1.75, 1.76, 1.77, 1.78, 1.79, 1.8, 1.81, 1.82, 1.83, 1.84 or 1.85. Further, the ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate may be in the range of one or more of the above values and one or less of the above values.

[0064] For example, the range of the ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate may be 0.65 to 1.85, 0.78 to 1.2, 0.58 to 1.2, 0.98 to 1.2, 0.9 to 1.2, 0.9 to 1.3, 1 to 1.2, 1 to 1.4, 1.18 to 1.58, 1.2 to 1.58, 1.38 to 1.58 or 0.78 to 1.58. According to one embodiment, when the ratio of the content of silicon dioxide and aluminum oxide contained in the aluminosilicate is applied within the above range, the slagging and fouling phenomena caused by the alkaline components of the biomass raw material can be effectively suppressed.

[0065] If the ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate is outside the range of 0.65 to 1.85, the efficiency of reacting with the alkali components released from the biomass raw material to produce high melting point substances (e.g., calcite, leucite, etc.) decreases, and it is not easy to prevent slagging and fouling phenomena.

[0066] According to one specific example, the weights of silicon dioxide and aluminum oxide contained in the aluminosilicate can be confirmed using X-ray fluorescence spectrometry. Therefore, the ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate can be calculated.

[0067] On the other hand, for the aluminosilicate according to one embodiment, when the temperature is raised from 400 °C to 800 °C, the weight loss rate can be 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less. For example, when the temperature is raised from 400 °C to 800 °C at a rate of 10 °C per minute, the weight loss rate of the aluminosilicate can be 5% or less. Here, the weight loss rate of the aluminosilicate can be calculated by the following formula 1.

[0068] [Equation 1] Weight loss rate of aluminosilicate (%) = (A - B) / A * 100 (where A is the weight of the aluminosilicate at 400 °C and B is the weight of the aluminosilicate at 800 °C)

[0069] The lower limit of the weight loss rate of the aluminosilicate according to one embodiment is not particularly limited, but can be, for example, 0.001% or more, 0.01% or more, or 0.05% or more.

[0070] The aluminosilicate according to one embodiment, unlike kaolin (such as kaolinite, halloysite, etc.), does not contain crystal water in the aluminosilicate. Therefore, the phenomenon that crystal water evaporates at high temperature and the total weight of the aluminosilicate decreases hardly occurs, and the weight loss rate is 5% or less at 400 to 800 °C.

[0071] In comparison, although the specific surface area value of kaolin may become larger than that at normal temperature as the crystal water contained therein evaporates at 400 to 800 °C, it is difficult for the specific surface area of kaolin to increase until the temperature at which the crystal water evaporates is reached. Therefore, it is difficult to quickly adsorb and remove the alkali components caused by the biomass raw materials.

[0072] However, the aluminosilicate according to one embodiment does not contain crystal water inside, and can maintain a specific surface area (for example, 100 to 180 m 2 / g) similar to that at normal temperature (for example, 20 to 25 °C) even at 400 to 800 °C. Therefore, it can adsorb and remove alkali components faster than kaolin.

[0073] In one embodiment, the calorific value of the black pellet can be 5500 cal / g to 7000 cal / g. As a specific example, the calorific value of the black pellet can be 5500 cal / g, 5600 cal / g, 5700 cal / g, 5800 cal / g, 5900 cal / g, 6000 cal / g, 6100 cal / g, 6200 cal / g, 6300 cal / g, 6400 cal / g, 6500 cal / g, 6600 cal / g, 6700 cal / g, 6800 cal / g, 6900 cal / g or 7000 cal / g. Also, the calorific value of the black pellet can be in the range of one or more of the above values and one or less of the above values.

[0074] For example, the calorific value of the black pellets can be in the range of 5500 cal / g to 7000 cal / g, 6000 cal / g to 7000 cal / g, 5500 cal / g to 6000 cal / g, or 6500 cal / g to 7000 cal / g. The black pellets according to one embodiment exhibit excellent combustion efficiency within the above calorific value range. If the calorific value of the black pellets is less than 5500 cal / g, the combustion efficiency will decrease. If one attempts to produce black pellets with a calorific value exceeding 7000 cal / g, there will be problems such as a complicated process and an increase in manufacturing cost.

[0075] The black pellets according to one embodiment may have an atomic H / C ratio (atomic hydrogen to carbon ratio) of 0.8 to 1.6. As a specific example, the atomic H / C ratio of the black pellets can be 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, or 1.6. Also, the atomic H / C ratio of the black pellets can be within the range of one or more of the above numerical values and one or less of the above numerical values.

[0076] For example, the atomic H / C ratio of the black pellets can be in the range of 0.8 to 1.6, 0.8 to 1, 1 to 1.6, 1 to 1.5, 0.9 to 1.3, or 1 to 1.4. When the atomic H / C ratio of the black pellets according to one embodiment is within the above range, they exhibit excellent combustion efficiency. If the atomic H / C ratio of the black pellets is less than 0.8, although the combustion efficiency is excellent, the manufacturing process of the pellets will become complicated and the manufacturing cost may increase. If the atomic ratio exceeds 1.6, the combustion efficiency may decrease.

[0077] The black pellets according to one embodiment may have an atomic O / C ratio (atomic oxygen to carbon ratio) of 0.2 to 0.8. As a specific example, the atomic O / C ratio of the black pellets can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8. Also, the atomic O / C ratio of the black pellets can be within the range of one or more of the above numerical values and one or less of the above numerical values.

[0078] For example, the atomic ratio of oxygen to carbon in the black pellets can be in the range of 0.2 to 0.8, 0.3 to 0.7, 0.4 to 0.6, or 0.2 to 0.5. When the atomic ratio of oxygen to carbon in the black pellets according to an embodiment is within the above range, excellent combustion efficiency is exhibited. If the atomic ratio of oxygen to carbon in the black pellets is less than 0.2, although the combustion efficiency is excellent, the pellet manufacturing process becomes complicated and the manufacturing cost may increase. If the atomic ratio exceeds 0.8, the combustion efficiency may decrease.

[0079] And in one embodiment, the atomic ratios (atomic H / C ratio and atomic O / C ratio) of the black pellets can be quantitatively measured by an elemental analyzer (as an example, Flash-EA1112 of Thermo Scientific).

[0080] Hereinafter, the present invention will be described in more detail based on specific examples and experimental examples. The following examples and experimental examples are merely examples for helping the understanding of the present invention, and the scope of the rights of the present invention is not limited thereto.

[0081] Manufacture of black pellets by example and comparative example <Examples 1 to 5 and Comparative Examples 1 to 2> After putting 1000 kg of palm empty fruit bunches into a press for pressing, the pressed material was put into a chamber. The chamber was sealed, and carbon dioxide, an inert gas, was injected at a flow rate of 1000 sccm through the inlet of the chamber, and the outlet was opened for 10 minutes to discharge the gas in the chamber to the outside of the chamber. With the inside of the chamber maintained in a carbon dioxide atmosphere (oxygen-free condition), the temperature inside the chamber was set to 200 to 300 °C for 10 to 15 minutes to heat-treat the pressed material. When the heat treatment was completed, carbon dioxide was injected into the inlet of the chamber at a flow rate of 1000 sccm, and the outlet of the chamber was opened to discharge the volatile components remaining in the chamber to the outside of the chamber for 10 minutes. Then, with the inside of the chamber in a carbon dioxide atmosphere, the temperature inside the chamber was maintained at 300 to 400 °C for 20 to 30 minutes to convert the raw material into semi-carbide, and the semi-carbide was put into a grinder and ground into particles of 0.1 to 5 mm. Then, 100 kg of the ground material, 10 kg of aluminosilicate, and 10 kg of a binder (myristic acid) were mixed in a stirrer and stirred at 300 rpm for 10 hours. After the stirring was completed, the mixture was put into a pellet molding machine to produce black pellets with a diameter of 6 mm and a length of 5 to 7 cm.

[0082] When manufacturing the black pellets, the weights of silicon dioxide and aluminum oxide of the aluminosilicate for each example and comparative example put into the stirrer were measured with an X-ray fluorescence spectrometer (ZSX Primus II manufactured by Rigaku Corporation), and the ratio obtained by dividing the content of silicon dioxide contained in the aluminosilicate by the content of aluminum oxide contained in the aluminosilicate was calculated and described in Table 1 below.

[0083]

Table 1

[0084] Experiment on suppressing slagging and fouling of black pellets by example and comparative example <Examples 1 to 5 and Comparative Examples 1 to 2> Black pellets for each example and comparative example were charged into a pilot test machine that modeled a circulating fluidized bed boiler in a thermal power plant and burned to compare the slagging and fouling suppression performance. The black pellets were charged into the test machine at a rate of 2.5 kg / hr for 3 hours. During the pilot test, the average temperatures of the combustion furnace and the measurement load cell were maintained at 850°C and 600°C, respectively. After the test was completed, the change in weight of the load cell was measured to measure the weight of slagging and fouling formed on the surface of the load cell (that is, the state in which the alkali components contained in the biomass raw material melted and solidified adhering to the surface of the load cell together with ash particles), and the results are shown in Table 2.

[0085]

Table 2

[0086] Referring to Table 2, it can be seen that in Examples 1 to 5 where the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is in the range of 0.65 to 1.85, the occurrence of slagging and fouling phenomena is relatively less compared to Comparative Examples 1 and 2. That is, the black pellets according to Examples 1 to 5 can effectively control the alkali components contained in the biomass raw material during combustion to suppress the occurrence of slagging and fouling phenomena, and can prevent the alkali components from reacting with chlorine to form chlorides. Therefore, it is possible to prevent chlorides from adhering to the inner wall of the boiler and metal parts and causing corrosion.

[0087] Measurement of specific surface area by BET method <Examples 1 to 5> After pretreating 0.1 g of the aluminosilicate sample charged into each example at 100°C to remove the surface water in the sample, the specific surface area of each sample was measured a total of 3 times using a BELSORP-max II instrument manufactured by MicrotracBEL in accordance with the standard analysis method ISO 9277:2010, and the average value is shown in Table 3 below.

[0088]

Table 3

[0089] Measurement of weight loss rate <Examples 1 to 5> 200 mg of the aluminosilicate sample used in each example was put into a thermogravimetric-differential scanning calorimeter (SDT Q600 of TA Instruments), and the temperature was raised from room temperature (25 °C) to 1,000 °C at a rate of 10 °C per minute. The weight of the aluminosilicate at 400 °C and 800 °C was measured, and the weight loss rate for each sample was calculated by the above-mentioned formula 1, and the results are shown in Table 4 below.

[0090]

Table 4

[0091] As described above, according to various embodiments of the present invention, by producing black pellets using biomass raw materials, it is possible to produce an environmentally friendly fuel with a high calorific value.

[0092] In addition, the black pellets according to various embodiments of the present invention can be co-fired with coal in a coal-fired power plant and can also be used as a fuel in a steel mill.

[0093] And, according to various embodiments of the present invention, during the combustion of the black pellets, the aluminosilicate, which is a combustion additive, reacts with specific components (for example, potassium, sodium, chlorine, etc.) contained in the biomass raw material to generate a substance with a high melting point. Therefore, it is possible to improve the thermal imbalance inside the boiler, slagging, fouling phenomenon, and corrosion problems caused by specific components present in the biomass raw material.

[0094] In particular, when manufacturing black pellets from palm empty fruit bunches, it is possible to reduce the costs associated with the waste treatment of palm empty fruit bunches, reduce the methane gas generated by the decay of palm empty fruit bunches, and when burning black pellets, potassium, chlorine components, etc. contained in palm empty fruit bunches are converted into high-melting-point substances by aluminosilicates, which contributes to the complete combustion of the fuel and can prevent in advance the corrosion of metal surfaces including the inner wall of the boiler.

[0095] And according to various embodiments of the present invention, by removing the volatile components of the pressed material through a volatile component removal process before the semi-carbonization process, the time and energy required for the semi-carbonization treatment can be reduced. Furthermore, since carbon dioxide can be injected into the chamber during the volatile component removal process and the semi-carbonization process to make the inside of the chamber an oxygen-free condition, the semi-carbonization treatment can be performed at a low cost compared to using other inert gases (for example, nitrogen, argon).

[0096] Also, according to various embodiments of the present invention, by controlling the alkali components contained in the biomass raw material without using kaolin, it is possible to suppress the slagging and fouling phenomena caused by the alkali components.

[0097] Furthermore, according to various embodiments of the present invention, since the aluminosilicate mixed with the semi-carbonized product has a small weight loss rate at high temperatures, it is easy to set the input amount of aluminosilicate, and since the loss due to ignition loss is small, even a relatively small amount compared to kaolin can control the alkali components.

[0098] Also, according to various embodiments of the present invention, since the aluminosilicate does not contain crystal water, it is possible to maintain a specific surface area of about 100 - 180 m 2 / g at room temperature (for example, 20 - 25 °C) without heat-treating the aluminosilicate at a high temperature of 400 - 800 °C. Due to the large specific surface area, it is possible to physically adsorb and remove the alkali components that melt and come out during the combustion of black pellets, thus preventing the slagging and fouling phenomena.

[0099] If the aluminosilicate contains crystal water, the specific surface area of the aluminosilicate may increase only by heat treatment at a high temperature to remove the crystal water. However, according to various embodiments of the present invention, since the aluminosilicate has a characteristic of having a high specific surface area value without separately removing the crystal water, there is an advantage that the alkali component can be controlled by a rapid adsorption reaction during the combustion of the black pellet.

[0100] As described above, the specific description of the present invention has been disclosed based on the embodiments. However, the above-described embodiments merely illustrate the preferred examples of the present invention, and it should not be understood that the present invention is limited only to the above embodiments. The scope of the rights of the present invention should be understood as the scope of the claims described below and the equivalent concept thereof.

Claims

1. A method for manufacturing black pellets for suppressing slagging and fouling phenomena in a combustion furnace of a boiler, which is used during combustion in the combustion furnace of the boiler, comprising: a squeezing step of squeezing a biomass raw material; a volatile component removing step of removing volatile components from the squeezed material squeezed in the squeezing step; a semi-carbonization step of semi-carbonizing the raw material from which the volatile components have been removed in the volatile component removing step; a pulverizing step of pulverizing the semi-carbonized material semi-carbonized in the semi-carbonization step; a mixing step of adding a combustion additive and a binder to the pulverized material pulverized in the pulverizing step and mixing them; a pelletizing step of forming the mixture mixed in the mixing step into pellets; wherein the combustion additive is aluminosilicate; The specific surface area of the aluminosilicate is 100 to 180 m 2 / g at room temperature without heat-treating the aluminosilicate, a method for manufacturing black pellets, characterized in that the average particle size of the aluminosilicate is 70 to 500 μm.

2. In the volatile component removing step, an inert gas is injected into the chamber in which the squeezed material is disposed, the squeezed material is heat-treated at 200 to 300 °C in a state where oxygen present in the chamber is removed, and volatile components emitted from the squeezed material are discharged to the outside of the chamber. The method for manufacturing black pellets according to Claim 1.

3. The method for manufacturing black pellets according to Claim 1, characterized in that the biomass raw material is at least one selected from wood by-products, empty fruit bunches (EFB), and palm kernel shells (PKS).

4. The method for manufacturing black pellets according to Claim 1, characterized in that the ratio of the content of silicon dioxide contained in the aluminosilicate to the content of aluminum oxide contained in the aluminosilicate is 0.65 to 1.

85.

5. Black pellets manufactured by the manufacturing method according to any one of Claims 1 to 4.

Images