JP7726952B2 - Palm empty fruit bunch pellet manufacturing method - Google Patents

Description

This disclosure relates to a method for producing palm empty fruit bunch pellets.

Since the Paris Climate Agreement was signed in 2015, countries around the world have implemented renewable energy revitalization programs to reduce carbon dioxide emissions, expand the renewable energy market, and improve competitiveness.

Demand for biomass fuel pellets, a new type of wood-based energy source, is increasing significantly as fuel for biomass co-firing or dedicated boilers, and Korean Patent Registration No. 10-0878051 presents technology for a method of manufacturing wood pellets.

However, producing pellets using wood or wood by-products as the primary material has limitations on the quantity that can be produced, making it difficult to flexibly respond to rapidly changing market demand.

Recently, as an alternative to existing wood pellets, empty palm fruit bunches (EFBs), which are produced in large quantities in Southeast Asia, particularly Malaysia and Indonesia, are being used to produce pellets. Empty palm fruit bunches are a by-product of palm fruit production and are the part that remains after the fruit bunches have been removed from the palm fruit.

However, when cultivating palm fruits on palm farms, large amounts of various fertilizers are used to increase yields, and it has been confirmed that palm empty fruit bunches contain large amounts of alkaline components such as potassium (K) and sodium (N).

When pellets made from palm empty fruit bunches are burned in a boiler, the alkaline components (e.g., _K2O , _Na2O ) contained in the palm empty fruit bunches are highly volatile and have a short residence time inside the boiler, which not only causes uneven combustion but also reacts with ash in the furnace to coat the inner walls of the boiler, resulting in corrosion of metal surfaces including the inner walls of the boiler.

In addition, low-melting-point inorganic substances contained in the palm empty fruit bunches used in pellets melt and flow during the pellet combustion process, adhering to the boiler's inner walls and heat exchange parts, causing slagging and fouling.

This phenomenon significantly reduces the boiler's thermal efficiency, disrupts the flow pattern within the combustion furnace, and even causes serious damage to the boiler's inner walls, so there is a need to develop new technology that can address these existing problems.

Korean Patent No. 10-0878051

The technical concept of this disclosure is intended to solve the problems described above, and aims to provide technology that allows by-products that have traditionally been incinerated or discarded to be reused as fuel.

Another objective of the technical concept of this disclosure is to provide a technology for producing fuel using palm empty fruit bunches.

Another objective of the technical concept of the present disclosure is to provide technology that can increase the combustion efficiency of pellets produced from palm empty fruit bunches and improve thermal imbalance, slagging, fouling, and corrosion problems inside boilers caused by specific components present in palm empty fruit bunches when the pellets are burned.

The problems that this disclosure aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the technical field to which this disclosure pertains from the content described below.

To achieve this objective, one embodiment of the present invention relates to a method for producing palm empty fruit bunch pellets, which includes a grinding step in which palm empty fruit bunches (EFB), a by-product of palm trees, are ground to produce a ground material, a mixing step in which an additive is added to the ground material to produce a mixture, and a pellet molding step in which the mixture is molded to produce pellets, wherein the additive includes an aluminosilicate.

The method for producing palm empty fruit bunch pellets may further include a drying step for drying the palm empty fruit bunches and an impurity removal step for removing impurities from the palm empty fruit bunches.

The aluminosilicate may have a specific surface area of 100 to 180 ^{m 2} /g as measured in accordance with the International Organization for Standardization ISO 9277:2010 standard.

The ratio of the silicon dioxide content contained in the aluminosilicate divided by the aluminum oxide content contained in the aluminosilicate may be 0.78 to 1.58.

The aluminosilicate may exhibit a weight loss rate of 5% or less when heated from 400°C to 800°C.

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

As described above, according to various embodiments of the present invention, palm empty fruit bunches are used to produce palm empty fruit bunch pellets, making it possible to produce environmentally friendly fuel with excellent combustion efficiency.

Furthermore, according to various embodiments of the present disclosure, when producing palm empty fruit bunch pellets, it is possible to reduce the cost of waste disposal of palm empty fruit bunches and reduce the methane generated by the decay of palm empty fruit bunches.

Furthermore, according to various embodiments of the present disclosure, when palm empty fruit bunch pellets are burned, the additive (aluminosilicate) can react with specific components (e.g., potassium, sodium, chlorine, etc.) contained in the palm empty fruit bunches to produce a substance with a high melting point. This can therefore improve thermal imbalance, slagging and fouling phenomena, and corrosion problems inside the boiler caused by specific components present in the palm empty fruit bunches.

In particular, when producing pellets from empty palm fruit bunches, it is possible to reduce waste disposal costs for empty palm fruit bunches and reduce the methane gas generated by the decay of empty palm fruit bunches.When empty palm fruit bunch pellets are burned, the alkaline components contained in the empty palm fruit bunches are converted into high-melting point substances by aluminosilicate, which contributes to the complete combustion of fuel and prevents corrosion of metal surfaces, including the inner walls of boilers.

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

1 is a flowchart schematically illustrating a method for manufacturing palm empty fruit bunch 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 for the sake of brevity, previously known technical aspects will be omitted or simplified.

It should be noted that references herein to "one" or "an" embodiment of the present invention do not necessarily refer to the same embodiment, but rather to at least one.

In the following examples, singular expressions include plural expressions unless the context clearly dictates otherwise.

In the following examples, terms such as "include" or "have" mean that the features or components described in the specification are present, but do not preclude the possibility that one or more other features or components may also be added.

When an embodiment can be implemented differently, the order of certain steps may be performed differently from the order described. For example, two steps described in succession may be performed substantially simultaneously, or may be performed in the reverse order from that described. That is, the steps of the methods described herein may be suitably performed in any order unless otherwise noted in the specification or clearly contradicted by context.

A method for producing palm empty fruit bunch pellets according to one embodiment of the present invention will be described with reference to Figure 1, and for convenience, the description will be made in order.

1. Drying step <S101>
In this step, palm empty fruit bunches, which are a by-product of palm trees, can be dried using various known drying methods (e.g., hot air drying, natural drying, etc.).

According to one embodiment, in this step, the palm empty fruit bunches can be dried so that their moisture content is between 0% and 15%. Here, the moisture content of the palm empty fruit bunches refers to the percentage of water contained in the palm empty fruit bunches.

Specific examples include the moisture content of the palm empty fruit bunches, which may be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%. Furthermore, the moisture content of the palm empty fruit bunches dried in this step may be in a range of one or more of the above values and one or less of the above values.

For example, the moisture content range of palm empty fruit bunches can be 0% to 15%, 1% to 14%, 2% to 13%, 3% to 12%, 4% to 11%, 5% to 12%, 6% to 11%, 1% to 10%, or 5% to 12%.

Furthermore, the moisture content of palm empty fruit bunches may be one or more of the above values, or one or less of the above values. For example, the moisture content of palm empty fruit bunches may be 0% or more, over 0%, 0.1% or more, 1% or more, 2% or more, or 3% or more, or 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, or 10% or less.

2. Impurity Removal Step <S102>
In this step, impurities can be removed from the empty palm fruit bunches dried in step S101. According to one embodiment, when the empty palm fruit bunches are placed on a vibrating screen and the vibrating screen is operated, impurities or foreign matter (e.g., soil, stones, fallen leaves, etc.) attached to the empty palm fruit bunches fall below the vibrating screen, thereby separating the empty palm fruit bunches from the impurities. In one specific example, a vibrating screen with a mesh size of 10 to 20 mm can be used, but meshes of various sizes can also be applied depending on the situation. In addition to using a vibrating screen, impurities can also be removed from the empty palm fruit bunches using various known impurity removal methods.

3. Crushing step <S103>
In this step, the palm empty fruit bunches are fed into a crusher and crushed to produce a crushed material. According to one embodiment, in this step, the palm empty fruit bunches from which impurities have been removed in step S102 are crushed to produce a crushed material of a certain size. The crushed palm empty fruit bunches produced in this step are crushed to a certain size (e.g., 1 to 80 mm), which has the advantages of being easy to mix with additives in the mixing step described below and easy to pelletize by compression molding in the pellet molding step.

4. Mixing step <S104>
In this step, an additive may be added to the pulverized material to prepare a mixture. For example, in this step, a predetermined amount of additive may be dropped onto the pulverized material as it is transported on a conveyor belt to prepare a mixture. In this step, the additive may be added in an amount of 0.1 to 10 parts by weight (e.g., 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by weight) based on 100 parts by weight of the pulverized material.

According to one embodiment, the additive in this step may include an aluminosilicate. In this specification, 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) atoms relative to aluminum (Al) atoms is 1 to 5.

The aluminosilicate may have a specific surface area of 100 to 180 ^{m 2} /g as measured in accordance with the International Organization for Standardization (ISO) 9277:2010. Specific examples of the specific surface area of the aluminosilicate include 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, and 180 m ² /g. The specific surface area of the aluminosilicate may be in a range of one or more of the above values and one or less of the above values.

For example, the specific surface area range of the aluminosilicate can be 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 may be, for example, 300 m ² /g or less, 250 m ² /g or less, 200 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.

In one embodiment, the larger the specific surface area of the aluminosilicate, the easier it is to adsorb alkaline components (e.g., _K2O , _Na2O , etc.) and chlorides (e.g., KCl, HCl, etc.) generated during the combustion of palm empty fruit bunch pellets, thereby effectively suppressing slagging, fouling, and corrosion. If the specific surface area of the aluminosilicate is less than 100 ^m2 /g, the efficiency of physically adsorbing and capturing alkaline components generated from palm empty fruit bunch pellets decreases, making it difficult to sufficiently control slagging and fouling, and there is a risk of chlorides adhering to the inside of the boiler, causing corrosion of metal parts.

In one embodiment, the average particle size of the aluminosilicate may be 20 to 500 μm. Specific examples of the average particle size of the aluminosilicate include 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 200 μm, 300 μm, 400 μm, and 500 μm. Of course, depending on the implementation, the average particle size of the aluminosilicate may be adjusted depending on the combustion conditions.

According to one embodiment, the additive aluminosilicate may include silicon dioxide and aluminum oxide.

In one specific example, the content of aluminum oxide contained in the aluminosilicate may be 20 to 60 parts by weight. Specific examples include 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, or 60 parts by weight. Furthermore, the content of aluminum oxide may be one or more of the above values and one or less of the above values.

For example, the content range of aluminum oxide contained in the aluminosilicate may be 20 to 30 parts by weight, 30 to 40 parts by weight, 35 to 45 parts by weight, 40 to 50 parts by weight, or 20 to 60 parts by weight. In one embodiment, aluminum oxide in this range can effectively control the alkalinity of palm empty fruit bunch pellets.

If the aluminum oxide contained in the aluminosilicate falls outside the range of 20 to 60 parts by weight, it is difficult to effectively control the alkaline components released from the palm empty fruit bunch pellets when they are burned.

In one embodiment, the content of silicon dioxide contained in the aluminosilicate may be 40 to 80 parts by weight. Specific examples include 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, or 80 parts by weight. The content of silicon dioxide may be one or more of the above values and one or less of the above values.

For example, the content range of silicon dioxide contained in the aluminosilicate may be 40 to 50 parts by weight, 50 to 60 parts by weight, 55 to 65 parts by weight, 60 to 70 parts by weight, 55 to 70 parts by weight, or 40 to 80 parts by weight. Silicon dioxide according to one embodiment can effectively control the alkaline components in palm empty fruit bunch pellets within this range. If the silicon dioxide contained in the aluminosilicate is outside the range of 40 to 80 parts by weight, it is difficult to effectively control the alkaline components released from the palm empty fruit bunch pellets when they are burned.

According to one embodiment, when palm empty fruit bunch pellets are burned, the additive aluminosilicate chemically reacts with the alkaline components contained in the palm empty fruit bunches, thereby converting the alkaline components released from the palm empty fruit bunches into at least one of kalsilite (KAlSiO ₄ ) and lucite (KAlSi ₂ O ₆ ).

In other words, when the palm empty fruit bunch pellets are burned, the alkaline components contained in the palm empty fruit bunch pellets react with the additive aluminosilicate and are converted into kalsilite, which has a melting point of over 1600°C, or lucite, which has a melting point of over 1500°C. This improves the problems of slagging, fouling, and coagulation that previously occurred when alkaline components melted in boilers.

According to one embodiment, the ratio of the silicon dioxide content in the aluminosilicate divided by the aluminum oxide content in the aluminosilicate may be 0.78 to 1.58. In one specific example, if the silicon dioxide content in the aluminosilicate is 48 parts by weight and the aluminum oxide content in the aluminosilicate is 42 parts by weight, the ratio of the silicon dioxide content in the aluminosilicate divided by the aluminum oxide content in the aluminosilicate may be 1.14.

As specific examples, the ratio of the silicon dioxide content in the aluminosilicate divided by the aluminum oxide content in the aluminosilicate is 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. The value may be 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, or 1.58. In addition, the ratio of the silicon dioxide content in the aluminosilicate divided by the aluminum oxide content in the aluminosilicate may be in a range from one or more of the above values to one or less of the above values.

For example, the ratio of the silicon dioxide content contained in the aluminosilicate divided by the aluminum oxide content contained in the aluminosilicate may be in the range of 0.78 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, the silicon dioxide to aluminum oxide content ratio contained in the aluminosilicate within this range can react with the alkaline components of the palm empty fruit bunch pellets, effectively suppressing slagging and fouling.

If the ratio of the silicon dioxide content in the aluminosilicate divided by the aluminum oxide content in the aluminosilicate falls outside the range of 0.78 to 1.58, the efficiency of producing high-melting-point substances (e.g., kalsilite, lucite, etc.) that react with the alkaline components released from the palm empty fruit bunch pellets during pellet combustion decreases, making it difficult to prevent slagging and fouling.

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

Meanwhile, according to one embodiment, when the aluminosilicate is heated from 400°C to 800°C, the weight loss rate may 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 increased 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 equation 1.

[Formula 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)

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 of one embodiment does not contain water of crystallization within the aluminosilicate. Therefore, the phenomenon of the water of crystallization evaporating at high temperatures and causing a decrease in the total weight of the aluminosilicate hardly occurs, and the weight loss rate is 5% or less at 400 to 800°C.

In contrast, kaolin's specific surface area may become larger than at room temperature as the water of crystallization contained within it evaporates at temperatures between 400 and 800°C. However, since kaolin's specific surface area does not increase until it reaches the temperature at which the water of crystallization evaporates, it is difficult to quickly adsorb and remove the alkaline components released from the empty palm fruit bunches.

However, the aluminosilicate according to one embodiment does not contain crystal water inside and can maintain a specific surface area (e.g., 100-180 ^m2 /g) at 400-800°C similar to that at room temperature (e.g., 20-25°C), so it can adsorb and remove alkaline components more quickly than kaolin.

In one embodiment, the aluminosilicate may further contain unavoidable impurities, the remaining amount being the remainder excluding the aluminum oxide and silicon dioxide content.

Meanwhile, at this stage, a binder can be further added to the mixture. Non-limiting examples of binders include myristic acid, palmitic acid, oleic acid, and castor oil. According to one embodiment, the binder can be added in an amount of 0.1 to 15 parts by weight (e.g., 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, 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 ground material.

5. Pellet forming step <S105>
In this step, the mixture mixed in step S104 may be introduced into a pelletizer and molded to produce pellets. According to one embodiment, the mixture may be introduced into a compression molding machine and compressed into pellets. During compression molding in this step, the mixture may be compressed at a strength of 10 to 500 MPa. For example, when the mixture is compression molded, the compressive strength may be 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, 120 MPa, 140 MPa, 160 MPa, 180 MPa, 200 MPa, 220 MPa, 240 MPa, 260 MPa, 280 MPa, 300 MPa, 320 MPa, 340 MPa, 360 MPa, 380 MPa, 400 MPa, 420 MPa, 440 MPa, 460 MPa, 480 MPa, or 500 MPa. The compressive strength of the mixture may be in a range of one or more of the above values and one or less of the above values.

If the compression strength of the compression molding machine for the mixture is less than 10 MPa, it will not be possible to compress it sufficiently, which may result in a significant reduction in the amount of heat produced compared to the pellet volume. If it exceeds 500 MPa, the pellet shape may collapse, resulting in a high reject rate.

According to one specific example, in this step, the mixture fed into the pelletizer is extruded to a diameter of 3 to 10 mm, and the extrudate is cut to a certain length (e.g., 20 to 50 mm) to produce pellets. Of course, the diameter and length of the pellets produced in this step can be appropriately changed as needed.

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

Production of palm empty fruit bunch pellets in Examples and Comparative Examples <Examples 1 to 5 and Comparative Examples 1 and 2>
The palm empty fruit bunches were naturally dried until their moisture content reached 10-15%, and then the dried palm empty fruit bunches were placed on a vibrating screen with a mesh size of 10-20 mm and operated for 30 minutes to remove impurities. Then, 100 kg of the impurity-removed palm empty fruit bunches were placed in a crusher and crushed to produce a crushed product with an average particle size of 20-80 mm. A mixture was prepared by adding 10 parts by weight of aluminosilicate and 10 parts by weight of a binder (myristic acid) to 100 parts by weight of the crushed product, and the mixture was stirred at 300 rpm for 10 hours. The mixture was then placed in a compression molding machine. The mixture was compressed at a strength of 300 MPa in the compression molding machine, and palm empty fruit bunch pellets with a diameter of 5-10 mm and a length of 30-50 mm were produced through extrusion and cutting processes.

The weights of silicon dioxide and aluminum oxide in the aluminosilicates of the Examples and Comparative Examples that were added to the mixer during the production of black pellets used in the production of palm empty fruit bunch pellets were measured using an X-ray fluorescence spectrometer (Rigaku's ZSX Primus II), and the ratios obtained by dividing the silicon dioxide content in the aluminosilicate by the aluminum oxide content in the aluminosilicate were calculated and are shown in Table 1 below.

Experiments on Slagging and Fouling Suppression of Black Pellets in Examples and Comparative Examples <Examples 1 to 5 and Comparative Examples 1 and 2>
Palm empty fruit bunch pellets from each of the examples and comparative examples were fed into a pilot test machine modeled after a circulating fluidized bed boiler used in a thermal power plant and burned to compare their slagging and fouling suppression performance. The palm empty fruit bunch pellets were fed into the test machine at a rate of 2.5 kg/hr for three hours, and the average temperatures of the combustion furnace and measurement load cell were maintained at 850°C and 600°C, respectively, during the pilot test. After the test was completed, the weight change of the load cell was measured to determine the weight of the slagging and fouling formed on the surface of the load cell (i.e., the alkali components contained in the palm empty fruit bunch raw material melted and solidified on the surface of the load cell together with ash particles). The results are shown in Table 2.

Referring to Table 2, it can be seen that Examples 1 to 5, in which the ratio of the silicon dioxide content contained in the aluminosilicate divided by the aluminum oxide content contained in the aluminosilicate was within the range of 0.78 to 1.58, experienced relatively less slagging and fouling compared to Comparative Examples 1 and 2. In other words, when the palm empty fruit bunch pellets according to Examples 1 to 5 were burned, the additive aluminosilicate effectively controlled the alkaline components contained in the palm empty fruit bunches, thereby suppressing the occurrence of slagging and fouling, and preventing the alkaline components from reacting with chlorine to form chlorides, thereby preventing chlorides from adhering to the inner walls and metal parts of the boiler and causing corrosion.

Measurement of specific surface area by BET method <Examples 1 to 5>
0.1 g of the aluminosilicate sample used in each example was pretreated at 100°C to remove surface water from the sample, and then the specific surface area of each sample was measured three times using a BELSORP-max II instrument manufactured by MicrotracBEL in accordance with the standard analytical method ISO 9277:2010, and the average values were listed in Table 3 below.

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

Preparation of conical samples for Examples and Comparative Examples <Examples 1 to 5 and Comparative Examples 1 to 2>
The palm empty fruit bunch pellets prepared in each of the Examples and Comparative Examples were calcined at 550°C to produce ash in accordance with ISO 18122 Solid biofuels. The prepared ash samples were placed in a conical mold and pressurized at 20 MPa for 2 minutes to produce conical samples in each of the Examples and Comparative Examples.

High temperature stability experiment <Examples 1 to 5 and Comparative Examples 1 and 2>
In order to confirm the stability of the conical samples prepared in the Examples and Comparative Examples at high temperatures, an experiment was carried out based on the ash solubility test method (ISO 540 Determination of fusibility of ash), and the results are shown in Table 5 below.

Table 5 shows photographs of the shape of each conical sample as a function of temperature, as well as the temperature at which deformation begins to occur for each sample. The solubility test results in Table 5 indicate that Examples 1 to 5 all had thermal distortion temperatures of 1,000°C or higher, confirming their stability at high temperatures. In contrast, Comparative Examples 1 and 2 were found to have thermal distortion temperatures below 1,000°C. In other words, because Comparative Examples 1 and 2 have thermal distortion temperatures below 1,000°C, it can be seen that burning pellets from Comparative Examples 1 and 2 could result in melting and the generation of clinker in some sections of a circulating fluidized bed boiler at a thermal power plant.

As described above, according to various embodiments of the present disclosure, palm empty fruit bunches are used to produce palm empty fruit bunch pellets, which allows for the production of environmentally friendly fuel with excellent combustion efficiency.

Furthermore, according to various embodiments of the present disclosure, when producing palm empty fruit bunch pellets, it is possible to reduce the cost of waste disposal of palm empty fruit bunches and reduce the methane generated by the decay of palm empty fruit bunches.

Furthermore, according to various embodiments of the present disclosure, when palm empty fruit bunch pellets are burned, the additive (aluminosilicate aluminosilicate) can react with specific components (e.g., potassium, sodium, chlorine, etc.) contained in the palm empty fruit bunches to produce a substance with a high melting point. This can improve thermal imbalance, slagging, fouling, and corrosion problems inside the boiler caused by specific components present in the palm empty fruit bunches.

In particular, when producing pellets from empty palm fruit bunches, it is possible to reduce waste disposal costs for empty palm fruit bunches and reduce the methane gas generated by the decay of empty palm fruit bunches.When empty palm fruit bunches are burned, the alkaline components contained in the empty palm fruit bunches are converted into high-melting-point substances by aluminosilicate, which contributes to the complete combustion of fuel and prevents chloride corrosion of metal surfaces, including the inner walls of boilers.

In addition, according to various embodiments of the present invention, the alkaline components contained in palm empty fruit bunches can be controlled without using kaolin, thereby suppressing slagging and fouling caused by alkaline components.

Furthermore, according to various embodiments of the present invention, the aluminosilicate mixed with palm empty fruit bunches has a small weight loss rate at high temperatures, making it easy to set the amount of aluminosilicate added. Furthermore, since there is little loss due to ignition loss, the alkalinity can be controlled with a relatively small amount compared to kaolin.

In addition, according to various embodiments of the present invention, since the aluminosilicate does not contain water of crystallization, it can maintain a specific surface area of approximately 100 to 180 m ² /g at room temperature without heat-treating the aluminosilicate at high temperatures of 400 to 800°C. Due to the large specific surface area, it can physically adsorb and remove alkaline components (e.g., K, Na, K ₂ O, Na ₂ O, etc.) that are melted and released during pellet combustion, thereby preventing slagging and fouling.

If an aluminosilicate contains water of crystallization, the specific surface area of the aluminosilicate can only be increased by removing the water of crystallization through heat treatment at high temperatures. However, according to various embodiments of the present invention, the aluminosilicate has a high specific surface area without the need to separately remove the water of crystallization, which has the advantage that the alkaline components can be controlled through a rapid adsorption reaction when the pellets are burned.

As described above, the specific description of the present invention has been disclosed based on the embodiments, but the above-mentioned embodiments merely describe preferred examples of the present invention, and therefore the present invention should not be understood as being limited to the above-mentioned embodiments, and the scope of the present invention should be understood as the scope of the claims described below and their equivalent concepts.

Claims (4)

a crushing step of crushing palm empty fruit bunches (EFBs), which are a by-product of palm trees, to produce crushed material;
a mixing step of adding an additive to the pulverized material to prepare a mixture;
and forming the mixture into pellets.
the additive comprises an aluminosilicate;
a weight ratio of the content of silicon dioxide contained in the aluminosilicate divided by the content of aluminum oxide contained in the aluminosilicate is 0.9 to 1.2. The method for producing palm empty fruit bunch pellets includes:
a drying step of drying the palm empty fruit bunch;
The method for producing palm empty fruit bunch pellets according to claim 1, further comprising: removing impurities from the palm empty fruit bunches. 2. The method for producing palm empty fruit bunch pellets according to claim 1, wherein the aluminosilicate has a specific surface area of 100 to 180 ^{m 2} /g as measured in accordance with the International Organization for Standardization ISO 9277:2010. The method for producing palm empty fruit bunch pellets described in claim 1, characterized in that the aluminosilicate exhibits a weight loss rate of 5% or less when heated from 400°C to 800°C.