KR101524751B1 - Hybrid coal using hydrogel and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a hybrid coal using a hydrogel and a method for producing the same, and it is an object of the present invention to improve the energy efficiency by suppressing the re-adsorption of water even after the coal is dried and to improve the combustion efficiency of the two- It is intended to transform low grade coal into high grade coal. The present invention relates to a method for producing a hydrogel, comprising the steps of mixing a hydrogel mixed with glycerol and a hydrophilic polymer and coal having a plurality of pores formed on a surface thereof, drying a mixture of hydrogel and coal, And forming a gel coating layer on the surface of the hybrid coal, and a hybrid coal produced by the method.

Description

Technical Field [0001] The present invention relates to a hybrid coal using a hydrogel,

The present invention relates to a hybrid coal (HC) and a production method thereof, and more particularly, to a hybrid coal (HC) and a method for producing the same. More particularly, the present invention relates to a hydrocarbyl- The present invention relates to a hybrid coal using a hydrogel impregnated in pores and a method for producing the same.

Coal accounts for about 60% of the total fossil fuels, and low coal reserves with relatively high water content such as lignite and sub-bituminous coal account for half of the total coal reserves.

However, these low abundances have high water content, which hinders power generation efficiency in coal-fired power plants and generates relatively more carbon dioxide than high-grade coal with relatively low water content.

On the other hand, internationally, climate change agreements have been enacted to prevent global warming, thereby regulating all artificial emissions of greenhouse gases. In addition to introducing Renewable Portfolio Standard (RPS), efforts to reduce coal use Is underway.

As a alternative energy source of coal, a method of using wood pallet or wood chip with coal is considered, but it is difficult to supply the coal in a stable manner. In addition, new and renewable energy sources using sunlight or wind power are more difficult to substitute for coal because of high cost of power generation compared to fossil fuels.

Korean Patent No. 10-1195416 (October 23, 2012)

In order to solve this problem, a hybrid coal in which low grade coal is converted into high grade coal can be considered. Hybrid coal can be prepared by drying low-grade coal to lower the water content, and then mixing the dried low-carbon and glycerol. At this time, the pores of the dried low carbon are impregnated with glycerol and made into hybrid coal.

These hybrid coal shows improved combustion characteristics compared with conventional low carbon, but when moisture is reabsorbed, glycerol dilutes or escapes from coal pores.

In this case, the loss of fuel due to the escape of glycerol occurs, and in the case of glycerol which has escaped from the pore, combustion characteristic of glycerol, which is burned separately from coal, unlike the combustion characteristic of hybrid coal showing one combustion pattern, is shown. When this is applied to the power plant, oxygen is preferentially consumed excessively due to the large reactivity of glycerol at the front part of the burner, which in turn hinders the burning of low carbon, thereby increasing the amount of unburned carbon and reducing the power generation efficiency do.

Accordingly, an object of the present invention is to provide a hybrid coal using hydrogel which can increase the energy efficiency by suppressing re-adsorption of water even after drying of coal, and a method for producing the same.

Another object of the present invention is to provide a hybrid coal and / or coal using a hydrogel capable of suppressing the problem that the material impregnated into the pores of coal due to the re-adsorption of water is removed from the pores by increasing the binding force between the coal and the material impregnated into the pores of the coal. And to provide a method for manufacturing the same.

Another object of the present invention is to provide a hybrid coal using a hydrogel showing combustion characteristics of a two-in-one fuel and a method of manufacturing the same.

It is still another object of the present invention to provide a hybrid coal using a hydrogel for converting low grade coal into high grade coal and a process for producing the same.

In order to accomplish the above object, the present invention provides a method for producing a hydrogel, comprising: mixing a hydrogel mixed with glycerol and a hydrophilic polymer and coal having a plurality of pores formed on the surface thereof; And forming a hydrogel coating layer on the plurality of pores of the coal. The present invention also provides a method of producing a hybrid coal using the hydrogel.

In the method for producing hybrid coal according to the present invention, in the mixing step, the hydrogel is impregnated into a plurality of pores of the coal.

In the method for producing hybrid coal according to the present invention, in the mixing step, the hydrogel may contain 1 to 30% by weight of the hydrophilic polymer based on the glycerol.

In the method for producing hybrid coal according to the present invention, in the mixing step, the glycerol and the hydrogel may be respectively 1 to 20 wt% based on the coal.

In the method for producing hybrid coal according to the present invention, the hydrophilic polymer may include polyester, polyisopropyl acryl amide (PNIAmm) or poly ethylene glycol (PEG).

In the method for producing hybrid coal according to the present invention, the hydrophilic polymer may be polyvinyl alcohol (PVA).

In the method of producing hybrid coal according to the present invention, the mixing step may include mixing the hydrophilic polymer and water at a temperature of 60 to 85 degrees Celsius, and injecting glycerol into the mixture of the hydrophilic polymer and water to produce a hydrogel Step < / RTI >

In the method for producing hybrid coal according to the present invention, in the mixing step, a curing agent may be mixed in the hydrogel before mixing the hydrogel and the coal.

In the method for producing hybrid coal according to the present invention, the curing agent may include borax.

In the method for producing hybrid coal according to the present invention, in the forming step, a mixture of the hydrogel and coal may be dried at 100 to 110 degrees.

In the method for producing hybrid coal according to the present invention, the coal may be peat, lignite, bituminous coal, bituminous coal or anthracite coal.

The method for producing hybrid coal according to the present invention may further include drying the coal, which is performed before the mixing step.

The present invention also provides a method for producing a hydrogel coating composition, comprising: a step of preparing a hydrogel coating layer comprising a coal having a plurality of pores formed thereon and a hydrogel coating layer coated on the pores of the coal, wherein the hydrogel coating layer comprises a hydrogel comprising a hydrogel mixed with glycerol and a hydrophilic polymer And provides a hybrid coal using a gel.

In the hybrid coal according to the present invention, the hydrogel coating layer may be formed by mixing the hydrogel with the coal so that the hydrogel is impregnated into a plurality of pores of the coal, and then drying the mixture of the hydrogel and the coal, Can be formed in pores.

In the hybrid coal according to the present invention, the hydrophilic polymer may include polyester, polyisopropyl acryl amide (PNIAmm), or poly ethylene glycol (PEG).

In the hybrid coal according to the present invention, the hydrophilic polymer may be polyvinyl alcohol (PVA).

In the hybrid coal according to the present invention, the hydrogel coating layer may include a carbonyl functional group.

In the hybrid coal according to the present invention, the hydrogel coating layer may include an O-H functional group, a C-H functional group, a C═O functional group, and a C-O functional group.

The hybrid coal according to the present invention has a structure in which a hydrogel coating layer is formed by impregnating pores of coal with a hydrogel mixed with glycerol and poly-vinyl alcohol (PVA) to form a hybrid coal Even if water is present around the hydrogel, the hydrogel coated on the pores of the coal hardly escapes out of the pores. That is, the binding energy between the hydrogel and the pores of the coal is greater than the binding energy between the hydrogel and water. This is because the metal component of the carbon ash support in the coal ash acts as a catalyst, Promoted and produced a group of carbonyl functional groups. Such a group of carbonyl functional groups strongly bonds the hydrogen bond between the glycerol derivative, polyvinyl alcohol and coal, so that even if water is reabsorbed to the hybrid coal, the hydrogel coated on the pores of the coal does not escape out of the pores.

As a result, the hybrid coal according to the present invention hardly causes loss of the hydrogel even in the presence of water. In other words, the hybrid coal according to the present invention can suppress the re-adsorption of water. Accordingly, the hybrid coal according to the present invention can improve the power generation efficiency and reduce the amount of generated carbon dioxide.

Further, the hybrid coal according to the present invention exhibits stable two-in-one fuel combustion characteristics because it has a structure in which hydrogels are stably impregnated into pores of coal. Therefore, the hybrid coal according to the present invention can increase energy efficiency.

Further, since the hybrid coal according to the present invention has a combustion delay effect, spontaneous combustion can be delayed.

Further, since the hybrid coal according to the present invention can be converted into high-grade coal by utilizing low-grade coal, utilization of low-grade coal can be promoted.

1 is a flow chart of a method for producing hybrid coal using hydrogel according to the present invention.
FIG. 2 is a flow chart showing the hydrogel-coal mixing step of FIG. 1;
FIG. 3 is a view showing a process of making coal from coal to hybrid coal according to the manufacturing method of FIG.
4 is an analysis table for analyzing components and calorific values of hybrid coal according to Examples and Comparative Examples of the present invention.
5 is a graph showing a TGA (Thermogravimetric analyzer) weight loss curve of a hybrid coal according to a comparative example of the present invention.
6 is a graph showing the TGA weight loss curve of PVA and PVA-added hydrogel.
7 is a graph showing a TGA weight loss curve of hybrid coal according to an embodiment of the present invention and a comparative example.
8 is a FT-IR (Fourier Transform Infrared Spectrometry) analysis graph of hybrid coal according to Examples and Comparative Examples of the present invention.
9 is a graph showing the initial ignition temperature of coal of Comparative Example 1. Fig.
10 is a graph showing the initial ignition temperature of the hybrid coal according to Comparative Example 2 of the present invention.
11 is a graph showing the initial ignition temperature of the hybrid coal according to the first embodiment of the present invention.
12 is a DTG (Differential Thermo Gravimetry) graph of hybrid coal according to Examples and Comparative Examples of the present invention.

In the following description, only parts necessary for understanding embodiments of the present invention will be described, and descriptions of other parts will be omitted to the extent that they do not disturb the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

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

1 is a flow chart of a method for producing hybrid coal using hydrogel according to the present invention. FIG. 2 is a flow chart showing the hydrogel-coal mixing step of FIG. 1; And FIG. 3 is a view showing a process of producing coal from coal to hybrid coal according to the manufacturing method of FIG.

1 to 3, a method for producing hybrid coal 70 according to the present invention includes preparing coal 50, drying the prepared coal 50, (S30) of mixing the hydrogel 61 and the coal 50 with the coal 50 and drying the mixture of the hydrogel 61 and the coal 50 to produce the hybrid coal 70 (S40). In this case, when the dried coal 50 is prepared in step S10 of preparing the coal 50, step S20 of drying the coal 50 may be omitted.

First, after the coal 50 is prepared in the step S10, the drying process for the coal 50 prepared in the step S20 may be performed. As described above, if the coal 50 dried in step S10 is prepared, step S20 may be omitted.

At this time, a plurality of pores 51 are formed on the surface of the coal 50. As the coal 50, peat, lignite, bituminous coal, bituminous coal or anthracite can be used, but the present invention is not limited thereto. In the present invention, hybrid coal 70 is basically produced from low-grade coal having a moisture content of, for example, 20 to 60% by weight, such as lignite and bituminous coal, but it may be a high-grade coal.

Next, in step S30, a hydrogel 61 mixed with glycerol and a hydrophilic polymer and a coal 50 having a plurality of pores 51 formed on its surface are mixed. At this time, the hydrogel 61 is impregnated into the plurality of pores 51 of the coal 50 in the mixing process.

Wherein the hydrogel 61 may comprise 5 to 30 weight percent hydrophilic polymer based on glycerol. Here, the hydrophilic polymer may include all polymers including functional groups capable of having a water-hydrogen bond such as polyester, polyisopropyl acryl amide (PNIAmm), and poly ethylene glycol (PEG). For example, polyvinyl alcohol (PVA) may be used as the hydrophilic polymer.

At this time, if the amount of the hydrophilic polymer is 5% by weight or less, gelation between the glycerol and the hydrophilic polymer may not be sufficiently performed and gelation to the hydrogel 61 may not be performed well. When the hydrophilic polymer is contained in an amount of 5% by weight or more, gelation to the hydrogel 61 is sufficiently performed. However, when the amount of the hydrophilic polymer is more than 30% by weight, it is not preferable because more hydrophilic polymer than necessary is used.

The glycerol and the hydrogel 61 may each contain 5 to 20% by weight based on the dried coal 50. In this case, when the amount of the hydrogel 61 is less than 5 wt%, the hydrogel 61 may be sufficiently impregnated into the pores 51 formed in the dried coal 50, and the hydrogel coating layer 60 may not be formed. Conversely, if the amount of the hydrogel 61 is more than 20% by weight, the hydrogel 61 may be impregnated into the plurality of pores 51 formed in the dried coal 50, but the excess hydrogel remaining on the surface of the dried coal 50 (61) exhibits properties as hydrogel (61) regardless of the characteristics of the hybrid coal (70) to be produced. Therefore, it is not preferable to use glycerol and hydrogel 61 in excess of 20 wt% or more.

On the other hand, in order to reduce the content of the hydrophilic polymer required for the gelation of the hydrogel 61, a curing agent may be used in the production of the hydrogel 61. At this time, borax may be used as a hardener. When a curing agent is used, the content of the hydrophilic polymer can be reduced to 5% by weight or less.

This step S30 may be performed as follows. First, in step S31, the hydrophilic polymer and water are mixed at a temperature of 60 to 85 degrees. Next, in step S33, glycerol is injected into the mixture of the hydrophilic polymer and water to prepare the hydrogel 61. [ The hydrogel 61 is impregnated into the pores 51 of the coal 50 by mixing the hydrogel 61 and the coal 50 manufactured in the step S35.

In step S40, a mixture of the hydrogel 61 and the coal 50 is dried to form the hydrogel coating layer 60 on the plurality of pores 51 of the coal 50. That is, the hydrogel 61 impregnated into the pores 51 of the coal 50 is dried to form the hydrogel coating layer 60 on the surfaces of the pores 51 of the coal 50, The hybrid coal 70 can be obtained.

At this time, the drying of the mixture of the hydrogel 61 and the coal 50 is preferably performed at a temperature lower than 150 ° C. at which the glycerol is volatilized, and preferably 100 ° C. to 110 ° C. .

Since the hybrid coal 70 manufactured by the manufacturing method of the present invention has the structure in which the hydrogel coating layer 60 is formed in the pores of the coal 50, The hydrogel coating layer 60 coated on the pores 51 of the pores 51 does not substantially deviate from the pores 51. That is, the binding energy between the hydrogel coating layer 60 and the pores 51 of the coal 50 is greater than the binding energy between the hydrogel coating layer 60 and water, The metal component containing carbon as a support serves as a catalyst, thereby promoting selective oxidation of glycerol and forming a carbonyl functional group. This group of carbonyl functional groups strengthens the hydrogen bonding between the glycerol derivative and the PVA and the coal 50 so that even if water is reabsorbed in the hybrid coal 70, The gel coating layer 60 does not fall out of the pores 51_.

As a result, the hybrid coal 70 according to the present invention hardly causes loss of the hydrogel even in the presence of water. In other words, the hybrid coal 70 according to the present invention can suppress the re-adsorption of water. Therefore, the hybrid coal 70 according to the present invention can improve power generation efficiency and reduce the amount of generated carbon dioxide.

In addition, since the hybrid coal 70 according to the present invention has a structure in which the hydrogel 61 is stably impregnated into the pores 51 of the coal 50, the stable two-in- one fuel combustion characteristics. Therefore, the hybrid coal 70 according to the present invention can increase energy efficiency.

Further, since the hybrid coal 70 according to the present invention has a combustion delay effect, spontaneous ignition can be delayed.

Further, since the hybrid coal 70 according to the present invention can be converted into high-grade coal by utilizing low-grade coal, utilization of low-grade coal can be promoted.

In order to evaluate the characteristics of the hybrid coal 70 produced by the manufacturing method of the present invention, the following characteristics evaluation experiments were conducted. Evaluation of combustion characteristics, FT-IR analysis evaluation, initial ignition temperature measurement, and glycerol loss were carried out in the characteristics evaluation experiment.

At this time, coal according to Example 1 and Comparative Examples 1 to 4 was prepared.

As Comparative Example 1, the bituminous coal dried with the dried coal was used. At that time, Kideco coal in Indonesia was used as the sub-coal. Here, the dried coal according to Comparative Example 1 can be expressed as "dried raw coal ".

As Comparative Examples 2 to 4, hybrid coal was used. The hybrid coal according to Comparative Example 2 contains 90 wt% of dried bituminous coal according to Comparative Example 1 and 10 wt% of glycerol. Here, the hybrid coal according to Comparative Example 2 can be expressed as "HC / G10 ".

The hybrid coal according to Comparative Example 3, Comparative Example 4 and Example 1 was produced by the production method according to the present invention, and each contained 90 wt% of the coarse coarse and 10 wt% of the hydrogel. At this time, the hybrid coal according to Comparative Example 3, Comparative Example 4 and Example 1 each contained 1 wt%, 3 wt% and 5 wt% of glycerol contained in the hydrogel. Here, the hybrid coal according to Comparative Example 3 is represented by "HC / H10 / P1". The hybrid coal according to the comparative example 4 can be denoted as "HC / H10 / P3", and the hybrid coal according to the first embodiment can be denoted as "HC / H10 / P5".

1. Evaluation of Combustion Characteristics

4 is an analysis table for analyzing components and calorific values of hybrid coal according to Examples and Comparative Examples of the present invention. 5 is a graph showing a TGA (Thermogravimetric analyzer) weight loss curve of a hybrid coal according to a comparative example of the present invention. 6 is a graph showing the TGA weight loss curve of PVA and PVA-added hydrogel. And FIG. 7 is a graph showing a TGA weight loss curve of hybrid coal according to an embodiment of the present invention and a comparative example. Figure 5 shows the TGA weight loss curves of Comparative Example 1, Glycerol, and Comparative Example 2. 7 shows the TGA weight loss curves of the hybrid coal of Comparative Example 3, Comparative Example 4 and Example 1. Fig.

The results of measurement of the components and calorific value of coal according to Comparative Example 1, Comparative Example 2 and Example 1 are shown in FIG. Since the calorific value of glycerol is 18.12 MJ / kg, which is lower than that of the coal according to Comparative Example 1, the hybrid coal according to Comparative Example 2 in which 10 weight% of glycerol is added has a slightly lower high heating value (HHV) , While the volatile content (VM) was increased by about 4.32 wt% as compared with Comparative Example 1.

On the other hand, it can be seen that the hybrid coal according to Example 1 has a slightly higher calorific value (23.30 MJ / kg) as compared with the coal of Comparative Example 1. It can be confirmed that the volatile content (VM) of Example 1 was increased by about 5.37 wt% as compared with Comparative Example 1. [

The combustion characteristics of the hybrid coal of Comparative Example 2 are such that the inherent characteristic of the glycerol impregnated in the pores of the coal starting to volatilize at 150 degrees is lost and as shown in FIG. 5, see. As the volatile matter in the coal increases, the combustion is slightly promoted. It is not a simple mixture of coal and biomass having different reactivity but literally two-in-one fuel fuel. In addition, the proper amount of glycerol for the preparation of Comparative Example 2 depends on the apparent porosity of coal. If the amount of glycerol exceeds the amount of pore of coal, the excess glycerol is present on the surface of coal And exhibits the inherent volatilization characteristics of glycerol, which begins to volatilize at about 150 degrees.

As shown in FIG. 6, the hydrogel prepared by adding PVA has no significant difference compared with the combustion characteristics of glycerol. Only the TG curve of the hydrogel to which 5% by weight of PVA had been added compared to glycerol only shifted to a slightly higher temperature because the PVA was burned in the high temperature region compared to the glycerol, although a small amount was added. In addition, the gelated state of each hydrogel is confirmed. The hydrogel (G99 / P1, G97 / P3) to which 1 wt% and 3 wt% of PVA are added has a liquid or semi-solid form at room temperature, Of PVA-added hydrogel (G95 / P5) show a solid form.

It can be said that the addition of 5 wt% or more of PVA in the preparation of the hydrogel results in more hydrogen bonding between the two substances and is advantageous for gelation of glycerol. On the other hand, if a cross-linking substance such as borax, that is, a hardening agent is added, the amount of PVA required for gelation can be reduced.

The solidified hydrogel affects the combustion characteristics of the hybrid coal. The combustion characteristics of the hybrid coal (HC / H10 / P5) according to Example 1 impregnated with a hydrogel having a weight ratio of glycerol and PVA of 95: 5 were measured by using other hybrid coal samples, that is, the hybrid coal according to Comparative Example 3 / P1) and the hybrid coal (HC / H10 / P3) according to Comparative Example 4 is delayed by about 150 degrees in the high temperature region. This is because the solid hydrogel is hydrogen bonded to the surface of the coal pores, which prevents diffusion of oxygen into coal pores. In addition, coal pores are mostly scattered in the ash, and since oxygen is absorbed at the interface between the fixed carbon (FC) and the ash, the coal having the ash dispersed evenly has a high reactivity to the combustion Because.

2. FT-IR analysis evaluation

FIG. 8 is a FT-IR analysis graph of hybrid coal according to Examples and Comparative Examples of the present invention. FIG. Here, FIG. 8 is FT-IR spectra of Comparative Examples 1 to 5 and Example 1. FIG.

FT-IR analysis was performed to investigate the functional groups present in Comparative Example 3, Comparative Example 4 and Example 1 where glycerol and hydrogel were applied.

In the dried coal of Comparative Example 1, as shown in FIG. 8, four major peaks that absorb wavenumbers can be found. The peak between 3200 and 3600 cm ^-1 indicates the presence of the hydroxyl functional group (OH), and the oscillation band of the CH alkyl group can be found in the region of 2900 cm ^-1 . The C = O and CO functional groups stretch and oscillate at 1600 cm ^-1 and 1050 cm ^-1 , respectively.

On the other hand, in the case of HC / G10 of Comparative Example 2, since the added glycerol abundantly contains OH and CO functional groups, it can be seen that the intensity of the peak at the corresponding wavenumber increases. The specificity here is that despite the absence of carbonyl functional groups in glycerol, intense peaks due to C = O functional groups can be found in the 1600 cm ^-1 region. This is because glycerol is selectively oxidized at the surface of carbon in the coal. When the hybrid carbon is prepared, glycerol is added and then dried in an oven. At this time, glycerol is converted into glycerol derivatives such as glycerol acid, dihydroxyacetone, , Meso-oxalic acid, and the like. Also, it can be seen that the absorption peaks of the hybrid coal according to Comparative Example 3, Comparative Example 4 and Example 1 impregnated with hydrogel corresponded to HC / G10 of Comparative Example 2. As the amount of PVA increased, The strength is reduced, and in particular, the HC / H10 / P5 of Example 1 shows a similar strength to that of the dried coal (Comparative Example 1). This is also considered to be a factor affecting the combustion delay of coal as described above.

3. Initial ignition temperature measurement

9 is a graph showing the initial ignition temperature of coal of Comparative Example 1. Fig. 10 is a graph showing the initial ignition temperature of the hybrid coal according to Comparative Example 2 of the present invention. And FIG. 11 is a graph showing the initial ignition temperature of the hybrid coal according to the first embodiment of the present invention. 9 to 11, T _furnace represents the heating temperature of the reactor, T _atmosphere represents the internal temperature of the reactor, and the remainder represents the temperature of the sample of Comparative Example 1, Comparative Example 2, and Example 1.

The grade of coal is a decisive factor of spontaneous ignition and has a tendency of autothermal reaction as oxygen function increases. The initial ignition temperature was measured using the cross point temperature (CPT) method to evaluate the spontaneous ignition characteristics. CPT is a method commonly used to measure spontaneous ignition by determining that the sample is ignited when the temperature of the coal sample is measured to be higher than the reactor internal temperature.

As can be seen from FIG. 9, in the case of the dried coal of Comparative Example 1, the CPT was measured at 215 degrees. As can be seen from FIG. 10, in the case of HC / G10 of Comparative Example 2 in which 10 weight% of glycerol was impregnated, the CPT was measured at 199 degrees. As can be seen from Fig. 11, the HC / H10 / P5 of Example 1 in which the hydrogel was impregnated had a CPT of 224 degrees.

The reason why the initial ignition temperature was measured differently is believed to be due to the inherent reactivity of each sample with respect to hydroxyl and carbonyl functional groups. This polar functional group, which contains active oxygen, will have a significant effect on the initial ignition temperature of each coal sample as well as the results of TGA and FT-IR analysis. It was also evaluated that the carbonyl functional groups generated from the selective oxidation of glycerol made the hydrogen bonding with the PVA or the surface of the coal pores stronger than the O-H functional group which is a single bond in glycerol and as a result retarded the initial ignition temperature.

4. Glycerol loss

For the hybrid coal, the loss of glycerol can be confirmed by DTG analysis according to FIG. The DTG indicates the weight reduction rate with temperature rise.

As can be seen from FIG. 12, the glycerol or hydrogel impregnated into the pores of the coal begins to burn at a temperature of 200 ° C or higher and disappears from its original characteristic of starting to volatilize below 150 ° C, like the volatile matter of coal.

The weight loss of HC / H10 / P5 of Example 1 and that of HC / G10 of Comparative Example 2 were the largest at about 350 degrees. However, the weight loss peak of HC / H10 / / G10. ≪ / RTI > In Comparative Example 2, the glycerol filled in the pores of the coal was diluted with water and then separated. In Example 1, however, the hydrogel stuck to the surface of the pores and burned as coal volatiles. That is, in the hybrid coal according to the second embodiment, the binding energy between the hydrogel and the surface of the coal pores is greater than the binding energy between the hydrogel and water. This is because the metal component, , Which promotes the selective oxidation of glycerol and produces a carbonyl functional group. These carbonyl groups strongly inhibit the hydrogen bond between the glycerol derivative, PVA and coal, and consequently the loss of glycerol due to the re-adsorption of water.

It should be noted that the embodiments disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

50: Coal
51: Groundwork
61: Hydrogel
60: Hydrogel coating layer
70: Hybrid coal

Claims (18)

Mixing a hydrogel mixed with 70 to 95% by weight of glycerol and 5 to 30% by weight of a hydrophilic polymer with coal having a plurality of pores formed on the surface thereof;
Drying a mixture of hydrogel and coal to form a hydrogel coating layer on the plurality of pores of the coal;
The method for producing hybrid coal using the hydrogel according to claim 1, 2. The method of claim 1, wherein in the mixing step,
Wherein the hydrogel is impregnated into a plurality of pores of the coal. The method according to claim 1,
Wherein the hydrogel coating layer comprises a carbonyl functional group. ≪ RTI ID = 0.0 > 11. < / RTI > 2. The method of claim 1, wherein in the mixing step,
Wherein the glycerol and the hydrogel are 5 to 20 wt% based on the coal, respectively. The method according to claim 1,
Wherein the hydrophilic polymer is polyvinyl alcohol (PVA). ≪ RTI ID = 0.0 > 8. < / RTI > The method according to claim 1,
Wherein the hydrophilic polymer comprises a polyester, a polyisopropyl acryl amide (PNIAmm), or a poly ethylene glycol (PEG). 2. The method of claim 1,
Mixing the hydrophilic polymer and water at a temperature of 60 to 85 degrees;
Injecting glycerol into the mixture of the hydrophilic polymer and water to prepare a hydrogel;
The method for producing hybrid coal using the hydrogel according to claim 1, 2. The method of claim 1, wherein in the mixing step,
Wherein the hydrogel is mixed with a curing agent before mixing the hydrogel and the coal. 9. The method of claim 8,
Wherein the hardener comprises borax. ≪ RTI ID = 0.0 > 8. < / RTI > The method according to claim 1, wherein in the forming step,
Wherein the mixture of hydrogel and coal is dried at 100 to 110 degrees. The method according to claim 1,
Wherein the coal is any one selected from among peat, lignite, bituminous coal, bituminous coal and anthracite coal. 2. The method of claim 1,
Drying the coal;
The method of claim 1, further comprising the steps of: And a hydrogel coating layer coated on the pores of the coal,
Wherein the hydrogel coating layer is made of a hydrogel mixed with 70 to 95% by weight of glycerol and 5 to 30% by weight of a hydrophilic polymer. 14. The method according to claim 13, wherein the hydrogel coating layer comprises:
Wherein the coal and the hydrogel are mixed so that the hydrogel is impregnated into the plurality of pores of the coal and then the mixture of the hydrogel and the coal is dried to form pores of the coal. . 14. The method of claim 13,
Wherein the hydrophilic polymer is a polyvinyl alcohol (PVA). 14. The method of claim 13,
Wherein the hydrophilic polymer comprises a polyester, a polyisopropyl acryl amide (PNIAmm), or a poly ethylene glycol (PEG). 14. The method according to claim 13, wherein the hydrogel coating layer comprises:
A hybrid coal using a hydrogel comprising a carbonyl functional group. 14. The method according to claim 13, wherein the hydrogel coating layer comprises:
Hybrid coal using a hydrogel containing an OH functional group, a CH functional group, a C = O functional group and a CO functional group.

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