JP2024013192A - Black pellet and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: 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

COPYRIGHT: (C)2024,JPO&INPIT

Description

TECHNICAL FIELD The present disclosure relates to black pellets and methods of manufacturing the same.

Since the 2015 Paris Climate Agreement, global efforts have continued to limit the rise in global average temperatures. As part of these 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.

New renewable energy refers to energy that is used 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 energies are renewable and non-depletable, are environmentally friendly as they emit less pollutants and carbon dioxide, and are distributed relatively evenly over the earth compared to fossil fuels. are doing.

Among new renewable energy sources, forest biomass is carbon-neutral energy and is known as an environmentally friendly renewable energy source that minimizes climate change and replaces fossil fuels. For example, wood pellets are made from wood left over from cutting down trees, or from forestry byproducts that have not been contaminated by chemicals such as preservatives and paints, which are made into sawdust and then compressed into a certain size. In this regard, Korean Patent No. 10-0878051 discloses a technique for producing wood pellets.

On the other hand, Empty Fruit Bunch (EFB) refers to the residue left after removing the palm fruit bunch in order to produce palm oil and the like from the palm fruit. Some of these palm waste, empty palm bunches, were used as livestock feed or compost, but the unused portion had to be incinerated or discarded.

By the way, empty palm fruit bunches are prone to rotting due to their high moisture content, and when empty palm fruit bunches rot, there is a problem in that methane gas, which is one of the greenhouse gases, is generated. The reality is that it is difficult to incinerate the fruit bunches, and it costs a lot of money to dispose of the waste. Therefore, from the standpoint of resource reuse and the environment, there is an urgent need to develop technology that can utilize discarded byproducts as fuel.

Korean Registered Patent No. 10-0878051

The technical idea of the present invention is to solve the above-mentioned problems, and its purpose is to provide a technology for producing fuel using biomass raw materials.

Another objective of the technical idea of the present invention is to provide a technology for reusing byproducts, which were conventionally incinerated or discarded, as fuel.

The problems to be solved by the present invention are not limited to the problems described above, and other technical problems not mentioned will be clearly understood by a person having ordinary knowledge in the technical field to which the present invention pertains from the content described below. It would be possible.

In order to achieve such an objective, as one embodiment of the present invention, a method for producing black pellets includes a pressing step of pressing a biomass raw material, and a step of removing volatile components from the compressed material squeezed in the pressing step. a volatile component removal step, a torrefaction step of torrefying the raw material from which the volatile components have been removed in the volatile component removal step, and a pulverization step of pulverizing the torrefied material that has been torrefied in the torrefaction step. a mixing step of adding and mixing a combustion additive and a binder to the pulverized material pulverized in the pulverizing step; and a pelletizing step of making pellets from the mixture mixed in the mixing step.

In the volatile component removal step, an inert gas is injected into the chamber in which the compressed product is placed, and the compressed product is heat-treated at 200 to 300 ° C. with oxygen present in the chamber removed, and the compressed product is heat-treated at 200 to 300 ° C. Volatile components coming out of the pressed product can be discharged to the outside of the chamber.

The biomass raw material may be at least one selected from wood byproducts, empty fruit bunches (EFB), and palm kernel shells (PKS).

The combustion additive is an aluminosilicate, and the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is 0.65 to 1. It can be 85.

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

In order to achieve the above object, in yet another embodiment of the present invention, the black pellets include a torrefied material obtained by torrefying palm empty fruit bunches, and an aluminosilicate mixed with the torrefied material. Can be done.

A ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate may be 0.65 to 1.85.

The calorific value of the black pellets may be 5500 cal/g to 7000 cal/g.

The black pellets 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.

The solutions described above are merely exemplary and should not be construed as intended to limit the invention. In addition to the exemplary embodiments described above, there may be additional embodiments described in the drawings and the detailed description.

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.

Further, the black pellets according to various embodiments of the present invention can be co-fired with coal in coal-fired power plants, and can be used as fuel in steel plants.

According to various embodiments of the present invention, when the black pellets are combusted, the aluminosilicate, which is a combustion additive, is added to the biomass raw material containing specific components (e.g., potassium, sodium, chlorine, etc.). ) can produce a substance with a high melting point. Therefore, thermal imbalance inside the boiler, slagging and fouling phenomena, and corrosion problems caused by certain components present in the biomass feedstock can be improved.

In particular, when producing black pellets from empty palm fruit bunches, it is possible to reduce the cost of waste treatment of empty palm fruit bunches, reduce methane gas generated by the decay of empty palm fruit bunches, and reduce the amount of black pellets. During combustion, the potassium and chlorine components contained in the empty palm bunches are converted into substances with high melting points by aluminosilicate, which contributes to complete combustion of the fuel and causes the metal surfaces, including the inner walls of the boiler, to become Corrosion can be prevented in advance.

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

1 is a flowchart schematically illustrating a method for manufacturing black pellets according to an embodiment of the present invention.

Preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings, but well-known technical parts will be omitted or compressed for the sake of brevity.

It must be noted that references herein to "one" or "an" embodiment of the invention are not necessarily to the same embodiment, but rather to mean at least one.

In the following examples, the singular expression includes the plural expression unless the context clearly indicates otherwise.

In the following examples, terms such as include or have mean that the feature or component described in the specification is present, and one or more other features or components may be added. It does not exclude gender in advance.

The particular order of steps may be performed differently from that described, if an embodiment is otherwise possible. For example, two steps described in succession can be performed substantially simultaneously, or can be performed in the opposite order of the described order. That is, the steps of the methods described herein may be suitably performed in any order, unless otherwise indicated in the specification or clearly indicated to the contrary by context.

The term "black pellet" as used herein refers to a pellet that has a black color, and can be made black by a torrefaction process during pellet production.

The term "wood by-product" as used herein refers to by-products that are produced for purposes other than those necessary when processing wood, and that are unavoidably generated during the process of processing wood. For example, the wood byproduct can be waste wood, sawdust or bark.

A method for manufacturing black pellets according to an embodiment of the present invention will be described with reference to FIG. 1, and will be explained in order for convenience.

1. Squeezing process <S101>
In this step, the biomass raw material can be compressed. For example, in this step, the volume of the biomass raw material can be reduced and the density can be increased by putting the biomass raw material into a compressor and compressing the biomass raw material by applying a constant pressure.

According to one embodiment, the biomass raw material to be pressed in this step may be at least one selected from wood byproducts, empty palm fruit bunches, and palm kernel shells. The biomass raw materials can be used singly or in combination of two or more.

2. Volatile component removal step <S102>
In this step, volatile components can be removed from the compressed material squeezed in step S101. According to one embodiment, the compressed material is put into the chamber, the chamber is sealed, and the chamber controller opens the inlet of the chamber for a certain period of time to inject an inert gas (for example, carbon dioxide). However, by opening the outlet of the chamber and letting the gas in the chamber flow out of the chamber, oxygen present in the chamber can be removed.

In addition, when the oxygen concentration in the chamber is below a preset value, the chamber control section maintains the temperature inside the chamber at 200 to 300°C and heat-treats the pressed material, and removes volatile components from the pressed material from the chamber. It can be discharged to the outside. Here, the volatile component is a component that can be removed from the compressed product while evaporating as a gas when the compressed product is heated to 200° C. or higher.

According to one embodiment, in this step, the chamber controller maintains the temperature inside the chamber at 200 to 300° C. for 10 to 15 minutes, and then injects an inert gas into the inlet of the chamber and the outlet of the chamber. By opening the chamber, volatile components remaining in the chamber can be discharged to the outside of the chamber. After a certain amount of time has elapsed from the time the volatile components have been exhausted from the chamber, the chamber controller can close the outlet of the chamber.

3. Torrefaction step <S103>
In this step, the raw material from which volatile components have been removed in step S102 can be subjected to torrefaction treatment. For example, in this process, the chamber control unit converts the raw material into torrefied material by maintaining the temperature inside the chamber at 300 to 400°C for 20 to 30 minutes in an oxygen-free or low-oxygen atmosphere inside the chamber. be able to. Here, an oxygen-free atmosphere or a low-oxygen atmosphere is defined as a state in which the oxygen concentration in the chamber is below a preset value (or substantially oxygen-free) by supplying an inert gas into the chamber at a constant flow rate. a state of inert atmosphere).

According to one embodiment, the chamber controller 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 inject the gas in the chamber. By flowing out of the chamber, the oxygen present in the chamber is removed, the oxygen concentration is adjusted to below the preset value, and only when the oxygen concentration is below the preset value, the temperature inside the chamber is increased to 300%. The torrefaction process can be carried out by maintaining the temperature at ~400° C. for 20 to 30 minutes.

4. Grinding process <S104>
In this step, the torrefied material subjected to the torrefaction treatment in step S103 can be pulverized. For example, in this step, the torrefied material can be put into a pulverizer and pulverized so that the torrefied material has a certain average particle size range (for example, 0.1 to 5 mm).

5. Mixing step <S105>
In this step, a combustion additive and a binder can be added to and mixed with the pulverized material pulverized in step S104. In one embodiment, the combustion additive may be an aluminosilicate. As used herein, aluminosilicate refers to a combination of alumina (Al ₂ O ₃ ) and silica (SiO ₂ ). The aluminosilicate according to one embodiment may have a structure in which the number of silicon (Si) elements is 1 to 5 per aluminum (Al) element.

In one embodiment, the content of aluminosilicate is 0.1 to 10 parts by weight (for example, 0.1 parts 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) can be applied.

Non-limiting examples of binders that can be added in this step include myristic acid, palmitic acid, oleic acid, and castor oil. According to one embodiment, the amount of binder added is 0.1 to 15 parts by weight (for example, 0.1 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight) per 100 parts by weight of the pulverized material. , 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). can.

6. Pelletization step <S106>
In this step, the mixture mixed in step S105 can be made into pellets. According to one embodiment, the mixture mixed in step S105 can be fed into a pellet molding machine to produce pellets with a diameter of 4 to 10 mm and a length of 50 to 70 mm. According to one embodiment, the mixture fed into the pelletizing machine is extruded to have a diameter of 4 to 10 mm, and the extrudate can be cut into lengths to produce pellets. Of course, the diameter and length of the pellets produced in this step can be adjusted as necessary.

<Description of black pellets according to one example>
The black pellets according to one embodiment are produced by mixing torrefied material and aluminosilicate and pelletizing the mixture, and the black pellets are produced by mixing torrefied material obtained by torrefying palm empty fruit bunches and mixed with torrefied material. aluminosilicate.

The aluminosilicate according to one embodiment may have a specific surface area of 100 to 180 m ² /g, measured according to the International Organization for Standardization ISO 9277:2010 regulations. As a specific example, the specific surface area of 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 m ² /g can be applied. Further, the specific surface area of the aluminosilicate may range from one or more of the above numerical values to one or less of the above numerical values.

For example, the specific surface area range of aluminosilicates 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. The upper limit of the specific surface area of the aluminosilicate according to one embodiment is not particularly limited, but is, for example, 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. It can be.

When producing black pellets using biomass raw materials such as wood byproducts, empty palm fruit bunches, and palm kernel shells, due to the characteristics of the biomass raw materials, alkaline components (e.g., K, Na, K ₂ O, Na ₂ O, etc.) or It may contain some chlorine (Cl).

When black pellets are burned, the alkaline components released from the biomass raw material can cause slagging and fouling phenomena while adhering to the inner walls of the boiler and heat exchange parts, and the chlorine released from the biomass raw materials becomes alkaline at high temperatures. In one example, black pellets are produced by mixing aluminosilicate with biomass raw materials, which can corrode the metal inside the boiler while reacting with other components to form chlorides (e.g., KCl, NaCl, etc.). By manufacturing the black pellets, slagging and fouling phenomena can be prevented from occurring during combustion of black pellets, and the corrosion problem of boilers can be improved.

According to one embodiment, the larger the specific surface area value of aluminosilicate, the easier it is to adsorb alkali components and chlorides generated during the combustion of black pellets, and the more effectively metal corrosion, slagging and fouling phenomena can be prevented. can be suppressed to If the specific surface area of the aluminosilicate is less than 100 m ² /g, the efficiency of physically adsorbing and collecting alkali components and chlorides generated during the combustion of black pellets will decrease, resulting in slagging and fouling. The ring phenomenon cannot be adequately controlled, and there is a risk of chloride deposits inside the boiler and corrosion of metal parts.

In one embodiment, the average particle size of the aluminosilicate may be 20 to 500 μm. As a specific example, the average particle size of the aluminosilicate is 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. can do. Of course, depending on the implementation, it is also possible to adjust the average particle size of the aluminosilicate differently depending on the combustion situation.

In one example, the aluminosilicate can include silicon dioxide and aluminum oxide. The aluminosilicate according to one embodiment may also contain unavoidable impurities as a residual amount after excluding silicon dioxide and aluminum oxide.

According to one embodiment, the content of aluminum oxide contained in the aluminosilicate may be from 20 to 60% by weight, based on the total weight of the aluminosilicate. As a specific example, the content of aluminum oxide is 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. be able to. Also, the content of aluminum oxide may be more than one of the above values and less than one of the above values.

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

If the aluminum oxide contained in the aluminosilicate is out of the range of 20 to 60% by weight, the alkaline components and chlorides released from the biomass raw material during the combustion of black pellets can be effectively controlled. It's not easy.

In one embodiment, the content of silicon dioxide contained in the aluminosilicate may be 40 to 80% by weight based on the total weight of the aluminosilicate. As a specific example, the content of silicon dioxide is 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. be able to. Also, the content of silicon dioxide may be more than one of the above values and less than one of the above values.

For example, the content range of silicon dioxide contained in the aluminosilicate is 40% to 50% by weight, 50% to 60% by weight, 55% to 65% by weight, 60% to 70% by weight, 55% by weight It can be from % to 70% by weight or from 40% to 80% by weight. The silicon dioxide according to one embodiment can effectively control alkaline components and chlorides contained in the biomass raw material within the above range. If the silicon dioxide contained in the aluminosilicate is outside the range of 40 to 80% by weight, the alkaline components and chlorides released from the biomass raw material during the combustion of black pellets can be effectively controlled. It's not easy.

According to one embodiment, when the black pellets are burned, the aluminosilicate chemically reacts with the alkaline components and chlorides contained in the biomass raw material, resulting in the release of alkaline components and chlorides from the biomass raw material. The material can be converted to at least one of calcilite (KAlSiO ₄ ) and lucite (KAlSi ₂ O ₆ ).

In other words, alkaline components and chlorides generated during black pellet combustion react with aluminosilicate and are converted into calcilite with a melting point of 1600°C or higher or lucite with a melting point of 1500°C or higher. It is possible to improve the problems of slagging, fouling, and condensation that conventionally occurred due to the melting of alkaline components in the boiler, and it is possible to prevent metal corrosion problems caused by chlorides.

Meanwhile, according to one embodiment, the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate may be 0.65 to 1.85. In one specific example, if the silicon dioxide contained in the aluminosilicate is 48 parts by weight and the aluminum oxide contained in the aluminosilicate is 42 parts by weight, the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate may be 1.14.

As a specific example, the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is 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. In addition, the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is one or more of the above values and one or less of the above values. It can be in the range of .

For example, the range of the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is 0.65 to 1.85, 0.78 to 1.2 , 0.58-1.2, 0.98-1.2, 0.9-1.2, 0.9-1.3, 1-1.2, 1-1.4, 1.18-1 .58, 1.2-1.58, 1.38-1.58 or 0.78-1.58. According to one embodiment, when the content ratio of silicon dioxide and aluminum oxide contained in the aluminosilicate is applied within the above range, slagging and fouling phenomena caused by the alkaline components of the biomass raw material can be effectively suppressed. Can be done.

If the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is out of the range of 0.65 to 1.85, the biomass raw material Since the efficiency of generating high melting point substances (eg, calcilite, lucite, etc.) by reacting with the released alkaline components is reduced, it is difficult to prevent slagging and fouling phenomena.

According to one embodiment, X-ray fluorescence spectroscopy can be used to determine the weight of silicon dioxide and aluminum oxide contained within the aluminosilicate. Therefore, the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate can be calculated.

On the other hand, the aluminosilicate according to one embodiment has a weight loss rate of 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less when the temperature is increased from 400°C to 800°C. 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, It can be 0.4% or less, 0.3% or less, 0.2% or less or 0.1% or less. For example, when increasing the temperature from 400°C to 800°C at a rate of 10°C per minute, the weight loss rate of the aluminosilicate may be 5% or less. Here, the weight loss rate of the aluminosilicate can be calculated using the following formula 1.

[Number 1]
Weight reduction rate (%) of aluminosilicate = (AB)/A*100
(Here, A is the weight of aluminosilicate at 400°C, B is the weight of aluminosilicate at 800°C)

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

Unlike kaolin (e.g., kaolinite, halloysite, etc.), the aluminosilicate according to one embodiment does not contain water of crystallization within the aluminosilicate. There is almost no phenomenon in which the weight decreases, and the weight loss rate is 5% or less at 400 to 800°C.

In comparison, the specific surface area of kaolin may become larger than that at room temperature as the water of crystallization contained inside evaporates at 400 to 800°C, but once the temperature at which the water of crystallization evaporates is reached, Until this happens, the specific surface area of kaolin is difficult to increase, making it difficult to quickly adsorb and remove alkaline components originating from biomass raw materials.

However, the aluminosilicate according to one embodiment does not contain water of crystallization and has a specific surface area (e.g., 100-180 m 2 /g) at a level similar to that at room temperature (e.g., 20-25°C) even at ^400-800 °C. ), it can adsorb and remove alkaline components more quickly than kaolin.

In one example, the calorific value of the black pellets may be between 5500 cal/g and 7000 cal/g. As a specific example, the calorific value of black pellets is 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 can be applied. Further, the calorific value of the black pellets may range from one or more of the above values to one or less of the above values.

For example, the calorific value range of black pellets can be 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 example exhibit excellent combustion efficiency within the above range of calorific value. If the calorific value of the black pellets is less than 5,500 cal/g, the combustion efficiency will decrease, and if it is attempted to produce black pellets with a calorific value of more than 7,000 cal/g, the process will become complicated and the manufacturing cost will increase.

The black pellets according to one embodiment may have an atomic H/C ratio of 0.8 to 1.6. As a specific example, the atomic ratio of hydrogen to carbon in the black pellet is 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5 or 1.6. It can be. Further, the atomic ratio of hydrogen to carbon in the black pellets may range from one or more of the above values to one or less of the above values.

For example, the atomic ratio of hydrogen to carbon in black pellets is 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. It can be in the range of .4. When the atomic ratio of hydrogen to carbon of the black pellets according to one embodiment is within the above range, excellent combustion efficiency is exhibited. If the atomic ratio of hydrogen to carbon in the black pellets is less than 0.8, the combustion efficiency will be excellent, but the pellet manufacturing process will become complicated and the manufacturing cost may increase, and if the atomic ratio exceeds 1.6. For example, combustion efficiency may decrease.

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

For example, the atomic ratio of oxygen to carbon in the black pellets can range from 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 of 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, the combustion efficiency will be excellent, but the pellet manufacturing process will become complicated and the manufacturing cost may increase.If the atomic ratio exceeds 0.8, , combustion efficiency may decrease.

In one example, the atomic ratios (atomic H/C ratio and atomic O/C ratio) of the black pellet can be quantitatively measured using an elemental analyzer (for example, Flash-EA1112 from Thermo Scientific). .

Hereinafter, the present invention will be explained in more detail based on specific examples and experimental examples. The following examples and experimental examples are merely illustrative to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

Production of black pellets according to Examples and Comparative Examples <Examples 1 to 5 and Comparative Examples 1 to 2>
After putting 1000 kg of empty palm fruit bunches into a pressing machine and compressing them, the pressed product was put into a chamber. The chamber was sealed, and carbon dioxide, which is 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 inside the chamber to the outside of the chamber. While maintaining the inside of the chamber in a carbon dioxide atmosphere (anoxic condition), the temperature inside the chamber was set at 200 to 300° C. for 10 to 15 minutes, and the compressed material was heat-treated. 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. Ta. After that, while the inside of the chamber is in a carbon dioxide atmosphere, the temperature inside the chamber is maintained at 300 to 400 degrees Celsius for 20 to 30 minutes to turn the raw material into torrefied material, and the torrefied material is put into a pulverizer with a 0.1 to 0.1 It was ground into particles of 5 mm. Thereafter, 100 kg of the pulverized material, 10 kg of aluminosilicate, and 10 kg of a binder (myristic acid) were mixed in a stirrer, and the mixture was 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.

The weights of silicon dioxide and aluminum oxide in the aluminosilicate of each example and comparative example, which were introduced into the stirrer during the production of black pellets, were measured using an X-ray fluorescence spectroscopy instrument (Rigaku's ZSX Primus II), The ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate was calculated and is listed in Table 1 below.

Slagging and fouling suppression experiment of black pellets according to Examples and Comparative Examples <Examples 1 to 5 and Comparative Examples 1 to 2>
Slagging and fouling suppression performance was compared by injecting the black pellets of Examples and Comparative Examples into a pilot test machine modeled after a circulating fluidized bed boiler at a thermal power plant and burning them out. Black pellets were fed into the test machine at a rate of 2.5 kg/hr for 3 hours, and the average temperature of the combustion furnace and measurement load cell was maintained at 850° C. and 600° C., respectively, during the pilot test. After the test is completed, the amount of change in weight of the load cell is measured, and the results are as follows. The weight of the solidified product was measured, and the results are shown in Table 2.

Referring to Table 2, examples in which the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is within the range of 0.65 to 1.85. It can be seen that samples Nos. 1 to 5 cause relatively less slugging and fouling phenomena than Comparative Examples 1 and 2. That is, the black pellets according to Examples 1 to 5 can effectively control the alkaline components contained in the biomass raw material during combustion, suppressing the occurrence of slagging and fouling phenomena, and reducing the alkaline components. Since it is possible to prevent chloride from reacting with chlorine to form chloride, it is possible to prevent chloride from adhering to the inner walls and metal parts of the boiler and causing corrosion.

Specific surface area measurement by BET method <Examples 1 to 5>
After pre-treating 0.1 g of the aluminosilicate sample to be used in each example at 100°C to remove surface water within the sample, it was analyzed using a Microtrac BEL BELSORP-max II instrument according to the standard analytical method ISO 9277:2010. The specific surface area of each sample was measured three times in total, and the average value is listed in Table 3 below.

Weight loss rate measurement <Examples 1 to 5>
200 mg of the aluminosilicate sample used in each example was placed in a thermogravimetric differential scanning calorimeter (SDT Q600 from TA Instruments), and the sample was heated at 10°C per minute from room temperature (25°C) to 1,000°C. The weight of the aluminosilicate was measured at a temperature of 400° C. and 800° C., and the weight loss rate of each sample was calculated using Equation 1, and the results are shown in Table 4 below.

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.

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

According to various embodiments of the present invention, when the black pellets are combusted, the aluminosilicate, which is a combustion additive, is added to the biomass raw material containing specific components (e.g., potassium, sodium, chlorine, etc.). ) can produce a substance with a high melting point. Therefore, problems of thermal imbalance, slagging, fouling, and corrosion inside the boiler caused by certain components present in the biomass feedstock can be improved.

In particular, when producing black pellets from empty palm fruit bunches, it is possible to reduce the cost of waste treatment of empty palm fruit bunches, reduce methane gas generated by the decay of empty palm fruit bunches, and reduce the amount of black pellets. During combustion, the potassium and chlorine components contained in empty palm bunches are converted into high-melting-point substances by aluminosilicate, which contributes to complete combustion of the fuel and corrodes metal surfaces, including the inner walls of the boiler. This can be prevented in advance.

According to various embodiments of the present invention, by removing the volatile components of the pressed material through the volatile component removal process before the torrefaction process, the time and energy required for the torrefaction process can be saved. . Furthermore, in the volatile component removal process and torrefaction process, carbon dioxide can be injected into the chamber to create an oxygen-free condition inside the chamber, so other inert gases (e.g. nitrogen, argon) can be used. In comparison, torrefaction treatment can be performed at low cost.

Further, according to various embodiments of the present invention, slagging and fouling caused by alkaline components can be suppressed by controlling the alkaline components contained in the biomass raw material without using kaolin.

Furthermore, according to the various embodiments of the present invention, the aluminosilicate mixed with the torrefied material has a small weight loss rate at high temperatures, so it is easy to set the amount of aluminosilicate to be added, and the loss due to ignition loss is reduced. Because of its small amount, it is possible to control the alkaline component even in a relatively small amount compared to kaolin.

In addition, according to various embodiments of the present invention, since the aluminosilicate does not contain crystallization water, the aluminosilicate does not need to be heat-treated at a high temperature of 400 to 800 degrees Celsius at room temperature (for example, 20 to 25 degrees Celsius). ), it is possible to maintain a specific surface area of about 100 to 180 m ² /g, and the large specific surface area allows it to physically adsorb and remove the alkaline components that are melted and released when black pellets are burned. , slugging and fouling phenomena can be prevented.

If the aluminosilicate contains water of crystallization, the specific surface area of the aluminosilicate may be increased only by heat treatment at high temperature to remove the water of crystallization. For example, since aluminosilicate has a high specific surface area value without separately removing crystal water, it is possible to control alkaline components through rapid adsorption reaction when black pellets are burned. There are advantages that can be achieved.

As explained above, the specific explanation of the present invention has been disclosed based on the examples, but the above-mentioned examples merely explain preferred examples of the present invention, and the present invention is not limited to the examples described above. It should not be understood as being limited only to The scope of rights of the present invention should be understood as the following claims and equivalent concepts thereof.

Claims (9)

A squeezing process for squeezing biomass raw materials;
a volatile component removal step of removing volatile components from the compressed material squeezed in the pressing step;
a torrefaction step of torrefying the raw material from which the volatile components have been removed in the volatile component removal step;
a pulverizing step of pulverizing the torrefied material torrefied in the torrefying step;
a mixing step of adding and mixing a combustion additive and a binder to the pulverized material pulverized in the pulverizing step;
a pelletizing step of making pellets from the mixture mixed in the mixing step;
A method for producing black pellets, the method comprising: In the volatile component removal step, an inert gas is injected into the chamber in which the compressed product is placed, and the compressed product is heat-treated at 200 to 300 ° C. with oxygen present in the chamber removed, and the compressed product is heat-treated at 200 to 300 ° C. The method for producing black pellets according to claim 1, characterized in that volatile components released from the pressed material are discharged to the outside of the chamber. Claim 1, wherein the biomass raw material is at least one selected from wood byproducts, empty fruit bunches (EFB), and palm kernel shells (PKS). The method for producing black pellets described in . The combustion additive is an aluminosilicate, and the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is 0.65 to 1. 85, the method for producing black pellets according to claim 1. Black pellets produced by the production method according to any one of claims 1 to 4. A torrefied product obtained by torrefying palm empty fruit bunches,
an aluminosilicate mixed with the torrefied material;
A black pellet characterized by containing. Claim 6, characterized in that the ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is 0.65 to 1.85. Black pellets as described in. The black pellet according to claim 6, wherein the calorific value of the black pellet is 5500 cal/g to 7000 cal/g. 7. The black pellet according to claim 6, wherein the atomic ratio of hydrogen to carbon is 0.8 to 1.6, and the atomic ratio of oxygen to carbon is 0.2 to 0.8. black pellet.