KR20210122540A - Preparation method of hybrid coal using mixed bio extracted from herbaceous biomass - Google Patents

Abstract

The present invention relates to a method for manufacturing hybrid coal using a mixed bio liquid extracted from herbal biomass, wherein the mixed bio liquid extracted from herbal biomass is impregnated into low-grade coal for carbonization, thereby having a higher calorific value than that of low-grade coal due to a single combustion characteristic (two-in-one fuel) and having enough moldability to be manufactured into pellets and the like. According to the present invention, a method for manufacturing a modified hybrid coal impregnated with a mixed bio liquid comprises the following steps: preparing coal (S10); preparing a mixed solution (mixed bio liquid) containing sugar extracted from herbal biomass (S20); impregnating the mixed bio liquid into pores and surface of the coal (S30); drying the mixed bio liquid-impregnated coal to form a coating layer of the mixed bio liquid (S40); carbonizing the mixed bio liquid-impregnated coal at low temperature (S50); and forming the mixed bio liquid-impregnated coal (S60).

Description

Preparation method of hybrid coal using mixed bio extracted from herbaceous biomass

The present invention relates to hybrid coal and a method for producing the same, and more particularly, by using mixed bio extracted from herbal biomass to impregnate and carbonize the low coal to provide a single combustion characteristic (two-in-one fuel), the calorific value than the low coal. It relates to a method for producing hybrid coal using mixed biomass extracted from herbaceous biomass, which is excellent and has excellent moldability that can be produced into pellets or the like.

Recently, interest in coal as an energy source is rising again due to reasons such as continuously rising oil prices and distrust in the stability of nuclear energy. However, coal produces the largest amount of carbon dioxide among fossil fuels, so it is a weak energy source considering global warming. Therefore, one of the current global issues as an energy source is the use and dissemination of new and renewable energy, which reduces carbon dioxide emissions compared to the existing fossil fuels such as petroleum and coal, so that it can respond to global warming and climate change. Because it is in the spotlight as an energy source. However, in the case of using renewable energy sources such as solar power or wind power for power generation or heating in Korea, epoch-making use and dissemination were limited due to the difference in power generation cost compared to fossil fuels.

In Korea, as well as the depletion of fossil fuels and the rise of greenhouse gas reduction in response to the international treaty on climate change, the mandatory quota system for renewable energy began to be discussed. Since 2012, the Renewable Portfolio Standard (RPS) It is true that the introduction puts a burden on energy providers. Accordingly, power generation companies are attempting Integrated Gasification Combined Cycle (IGCC) and biomass co-firing as an effort to reduce carbon dioxide emissions from coal, but IGCC cannot use existing coal-fired power generation facilities, 1 It requires a huge construction cost of about 1.3 trillion won per unit, and it is a technology that additionally needs to install a carbon capture and storage facility [Carbon Capture and Storage (CCS)] for carbon dioxide treatment, which is very economically burdensome. And in the case of biomass co-firing, there is a problem such as a decrease in power generation efficiency due to combustion of biomass having a relatively low calorific value compared to coal.

In addition, as the supply of high-grade coal such as bituminous coal has recently become unstable, power generation companies inevitably have no choice but to use low-grade coal. , there is a problem that the amount of CO2 generated increases by more than 20% compared to high-grade coal. Therefore, considering that such low-grade coal occupies about 50% of the total coal reserves, the high value-added of low-grade coal is a necessary technology for efficient use of low-grade coal.

Accordingly, research on low coal drying such as simple drying of low coal, high pressure drying using hot water, or drying using high temperature organic solvent is being actively conducted. There is still the problem of low efficiency. In addition, in the case of low-grade coal, there is a problem in that spontaneous ignition occurs and thus stored coal is lost.

In addition, a technique for high-quality reforming of low-grade coal by a method of attaching tar in a biomass dry distillation product to coal is also known, but the re-adsorption of moisture has not been evaluated.

The problem to be solved by the present invention is that it is impregnated and carbonized in low-grade coal using mixed bio extracted from herbal biomass to have a single combustion characteristic (two-in-one fuel), which has superior calorific value than low-grade coal and can be manufactured into pellets. An object of the present invention is to provide a method for producing hybrid coal using mixed biomass extracted from herbal biomass having excellent moldability.

A method for producing hybrid coal using a mixed bio extracted from herbal biomass according to the present invention includes the steps of preparing coal (S10); Preparing a mixed solution (mixed bio) containing sugar extracted from herbal biomass (S20) and; Impregnating the mixed bio into the pores and the surface of the coal (S30) and; forming a coating layer of the mixed bio by drying the coal impregnated with the mixed bio (S40); Low-temperature carbonization of the mixed bio-impregnated coal (S50); characterized by including.

Preferably, the mixed bio is characterized in that it is mixed in an amount of 3 to 80% by weight, respectively, based on coal.

Preferably, the step of forming the coating layer of the mixed bio is characterized in that it is made at 80 ~ 120 ℃.

Preferably, the low-temperature carbonization step is characterized in that it is performed at 200 ~ 250 ℃ in an inert gas atmosphere.

Preferably, the inert gas is nitrogen gas.

Preferably, it characterized in that it further comprises a step (S60) of molding into coal briquettes of a predetermined shape after the step (S30) of impregnating the mixed bio.

According to the present invention, the mixed bio extracted from herbal biomass is impregnated into coal and carbonized at low temperature, so that the calorific value is superior to that of low-grade coal with a single combustion characteristic (two-in-one fuel). has the advantage of being

In addition, since mixed bio is used as a binder, it has a low moisture absorption rate and high compressive strength, so that its shape is maintained even when it is made of coal briquettes such as pellets.

In addition, the hybrid coal according to the present invention can increase the calorific value of the low-grade coal to replace the high-grade coal and promote the use of the low-grade coal.

1 is a flowchart for the manufacturing process of hybrid coal using a mixed bio extracted from herbal biomass according to the present invention.
2 is a photograph of moisture absorption and moldability test of hybrid coal impregnated with mixed bio according to the present invention.
3 is a graph of combustion characteristics of hybrid coal after being impregnated with mixed bio according to the present invention.
Figure 4 is a graph of the compression strength of the hybrid coal briquettes densified after being impregnated with the mixed bio according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in Figure 1, the method for producing hybrid coal using a mixed bio extracted from herbal biomass according to the present invention comprises the steps of preparing coal (S10); Preparing a mixed solution containing sugar extracted from biomass (hereinafter referred to as 'mixed bio') (S20); Impregnating the mixed bio into coal (S30) and; Drying the mixed bio-impregnated coal to form a coating layer (S40); and carbonizing the coal impregnated with mixed bio at low temperature (S50). And, it may further include the step of manufacturing the coal briquettes by molding the mixed bio-impregnated coal (S60).

In the coal preparation step of S10, low-grade coal such as peat, lignite, sub-bituminous coal, bituminous coal, or anthracite coal is used. Low-grade coal may be used in the form of crushed pulverized coal, coarsely pulverized coal, or lump, but is not limited thereto. At this time, it is also preferable to remove moisture from the coal in the preparation stage of the coal.

In the mixed bio preparation step of S20, the herbaceous biomass giant pampas grass or empty fruit bundles are heated at about 200 ° C to extract the mixed bio containing sugar and remove solid foreign substances to prepare the mixed bio. This mixed bio is impregnated in coal to prevent absorption of moisture and to act as a binder in the manufacture of coal briquettes, thereby making it possible to manufacture coal briquettes that maintain high strength, high density and shape.

In the mixed bio-impregnation step of S30, the mixed bio extracted from herbal biomass is mixed with 3 to 80 wt% based on the weight of the coal, and is impregnated into the pores and surface of the coal to form a paste. At this time, if the amount of mixed bio is less than 3% by weight, it is difficult to sufficiently impregnate the pores and surfaces of the coal.

The mixed bio coating layer formation step of S40 dries the moisture of the mixed bio after impregnating the pores and surface of the coal. By the drying step, the mixed bio is adhered to the pores and surface of the coal to form a coating layer.

In the low-temperature carbonization step of S50, the coal on which the coating layer of the mixed bio is formed is heated to 200-250° C. in an inert gas atmosphere to carbonize it at a low temperature. At this time, the low-temperature carbonization proceeds in an inert gas atmosphere such as nitrogen, so that the coal and the mixed biomass are carbonized without being ignited, so that the mixed biomass remains in the pores and the surface of the coal. Through this low-temperature carbonization process, the mixed bio is combined with coal so that coal has a single combustion characteristic (two-in-one fuel).

On the other hand, the coal briquettes manufacturing step of step S60 produces coal briquettes such as pellets that are easy to transport, store and process low-grade coal such as pulverized coal or coarsely pulverized coal impregnated with mixed bio. For example, coal briquettes are manufactured into pellets or the like using compression molding rolls rotating in opposite directions.

Hybrid coal, which is impregnated with mixed bio produced by the above method and undergoes torrefaction process, exhibits stable combustion characteristics of two-in-one fuel. Due to this, the hybrid coal according to the present invention can increase energy efficiency.

In addition, since the hybrid coal according to the present invention can be changed to high-grade coal by utilizing low-grade coal, it is possible to promote the utilization of low-grade coal.

Hereinafter, specific examples will be described in detail.

(Production of hydride coal)

Herbal biomass, giant pampas grass or palm pit (Empty Fruit Bunches) was heated at about 200 ℃ to extract the mixed bio containing sugar and remove foreign substances. The mixed bio was impregnated with 10 g of mixed bio from which foreign substances were removed and 100 g of low-grade coal with a particle size of 4 mm or less. Then, after forming into pellets using a compression molding roll, after drying at 105° C. for 6 hours, a low-temperature carbonization process was performed at 250° C. for 1 hour under a nitrogen atmosphere to prepare hybrid coal.

<Check moisture absorption and moldability>

In the manufacturing process of hybrid coal, coal briquettes (comparative example) formed into pellets by impregnating mixed bio into coal, coal briquettes dried at 200°C (comparative example), and coal briquettes carbonized at 250°C low temperature (Example 1) were each filled with water. After putting it in the beaker, it was confirmed whether the coal was leached, and it is shown in the photo of FIG. 2 .

As shown in FIG. 2 , when the low-temperature carbonization process was not performed, the coal briquettes absorbed moisture and it was confirmed that the pulverized coal was separated. In addition, in the case of coal briquettes dried at 200°C, the shape of the coal briquettes was maintained immediately after input, but the pulverized coal was gradually separated from the coal by absorbing moisture. . However, in the case of coal briquettes subjected to low-temperature carbonization at 250° C., moisture was not absorbed, so it was confirmed that the color of the water did not change even after 1 hour had elapsed, and the pulverized coal was not separated.

As such, it can be seen that the coal briquettes impregnated with the mixed bio extracted from the herbal biomass of the present invention undergoes low-temperature carbonization to maintain the shape of the coal briquettes as they are, and hardly absorb moisture.

<Check the calorific value>

Industrial analysis results and calorific value of Indonesian low-grade coal (ILRC), herbaceous biomass giant pampas grass or palm pit, molasses, black liquor solids (grinin), and sawdust are shown in Table 1 below.

Industry analysis (wt%) high calorific value
(kcal/kg) low calorific value
(kcal/kg) moisture volatile matter ash fixed carbon Low-grade ammunition (ILRC) 43.88 25.86 10.64 19.62 5,350 4,880 Molasses (dried) 2.68 67.85 9.29 20.18 3,250 2,940 Black liquor solid (Greenin) 5.14 44.58 42.92 7.36 3,070 2,850 sawdust 30.27 45.74 13.28 10.71 3,770 1,430 Mixed Bio (Giant Grasshopper) 2.64 52.29 16.29 28.78 4,380 4,110 Mixed Bio (EFB) 1.56 59.06 22.38 17.00 3,970 3,720

As shown in Table 1 above, it can be seen that the mixed bio extracted from the herbal biomass of the present invention has a significantly higher calorific value than molasses used as a biomass raw material in the conventional hybrid coal production, so it can be confirmed that it is suitable as a binder. <Combustion Check reaction characteristics>

The combustion characteristics of the hybrid coal impregnated with the mixed bio of Example 1 and low-temperature carbonized as a comparative example and the low-grade coal of Indonesia and the coal briquettes (comparative example) physically mixed with coal (comparative example) were shown in the graph of FIG. .

As can be seen from the graph of FIG. 3, the coal briquettes simply mixed with the mixed bio have dual combustion characteristics that both the combustion characteristics of the mixed bio and the combustion characteristics of coal, but the hybrid coal impregnated with the mixed bio and low-temperature carbonized hybrid coal of the present invention is a single It was confirmed that it has combustion characteristics. Due to this single combustion characteristic, the power generation efficiency of coal briquettes has an improved effect than that of low-grade coal.

<Checking Compressive Strength>

As in Example 1, 3%, 10%, 20%, and 30% of the mixed bio extracted from the herbaceous biomass giant pampas grass or EFB was impregnated in pulverized coal with moisture at 15% and 20% relative to the weight of coal, respectively. After molding, torrefied hybrid briquettes were prepared, respectively, and the compressive strength was measured and shown in the graph of FIG. 4 .

As shown in FIG. 4 , the higher the content of the mixed bio, the higher the compressive strength, and it can be confirmed that the formability is high by maintaining the shape of the coal briquettes even when it is molded into pellets.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those of ordinary skill in the art to which the present invention pertains Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

Claims (6)

Preparing coal (S10) and;
Preparing a mixed solution (mixed bio) containing sugar extracted from herbal biomass (S20) and;
Impregnating the mixed bio into the pores and the surface of the coal (S30) and;
forming a coating layer of the mixed bio by drying the coal impregnated with the mixed bio (S40);
Low-temperature carbonization of the mixed bio-impregnated coal (S50); A method of manufacturing a hybrid coal using a mixed bio extracted from herbal biomass, characterized in that it comprises. The method according to claim 1, wherein the hybrid biomass is mixed in an amount of 3 to 80% by weight, respectively, based on the coal. The method according to claim 1, wherein the step of forming the coating layer of the mixed bio is performed at 80 ~ 120 ℃ method for producing hybrid coal using the mixed bio extracted from herbal biomass. The method according to claim 1, wherein the low-temperature carbonization step is performed at 200 ~ 250 ℃ in an inert gas atmosphere. The method of claim 4, wherein the inert gas is nitrogen gas. The method according to claim 1, further comprising the step (S60) of molding into coal briquettes of a predetermined shape after the impregnation step (S30) of the mixed biomass. manufacturing method.

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