WO2013129744A1

WO2013129744A1 - High-calorific hybrid coal coated with biomass-derived carbon component, high-concentration hybrid coal slurry, and method for manufacturing same

Info

Publication number: WO2013129744A1
Application number: PCT/KR2012/006565
Authority: WO
Inventors: 이동욱; 최영찬
Original assignee: 한국에너지기술연구원
Priority date: 2012-02-29
Filing date: 2012-08-17
Publication date: 2013-09-06
Also published as: AU2012359295A1; CN103429718B; AU2012359295B2; JP2015513593A; CN103429718A

Abstract

The present invention relates to high-calorific hybrid coal in which a coal-specific natural carbon component and an artificial carbon component are mixed together, and the re-adsorption of moisture is reduced even after drying by coating the hydrophilic surface of low-grade coal with the coal component of a biomass-derived material and reforming the resulting product such that is hydrophobic, and to a method for manufacturing same. Also provided is high-calorific hybrid coal in which the re-adsorption of moisture is substantially reduced using a two-stage drying process. Also provided are a method for manufacturing high-concentration hybrid coal slurry, which includes a step of forming hybrid coal slurry by adding hybrid coal to a dispersion medium selected from among water and alcohol, water and surfactant, and water, alcohol, and surfactant, and the high concentration hybrid coal slurry manufactured thereby.

Description

High calorific value hybrid coal, high concentration hybrid coal slurry coated with biomass-derived carbon and their manufacturing method

The present invention relates to a hybrid coal in which the hydrophilic surface of coal is coated with a biomass-derived carbon component, and to a method for producing the same. More specifically, the hydrophilic surface existing in the raw or dry coal containing water contains a biomass-derived carbon component. The present invention relates to a high calorific value hybrid coal mixed with natural carbon components inherent in carbon and artificial carbon components derived from biomass, in which resorption of moisture is suppressed even after drying by coating with hydrophobically modified and a method for producing the same.

In addition, the present invention is a high calorific value hybrid coal in which the natural carbon component of the coal and the artificial carbon component derived from biomass is mixed into any one dispersion medium selected from water / alcohol, water / surfactant or water / alcohol / surfactant. A method for producing a high concentration hybrid coal slurry by addition and a high concentration hybrid coal slurry produced thereby.

Recently, interest in coal as an energy source is rising again due to rising oil prices and distrust of nuclear energy stability. As of 2007, the total fossil fuel reserves can be consumed for another 100 years, considering the current level of fossil fuel consumption. Fossil fuels, which account for about 60% of them, are coal. In particular, low-carbon coals such as lignite and sub-bituminous coal account for 50% of the total coal reserves, and low-carbon high value-adding technology is urgently needed. [Yvonne Traa, Chem. Commun. , 2010, 46, 2175] However, there are some important issues to overcome in order to make effective use of low-grade coal.

In fact, the coal-fired power plants There are a dual fuel lower carbon to solve the difficulties of high carbon supply, the power generation efficiency is reduced due to the high inherent moisture content (20-65wt%) the lower carbon is CO ₂ emissions accordingly advanced Tan It has a problem of more than 20% increase compared to [X. Li et al., Energy Fuels , 2010, 24, 160] In order to solve this problem, studies on low-carbon coal drying such as simple drying of low coal, high pressure drying using hot water, or high temperature organic solvents are underway. However, there are still problems in that the process is complicated and problems in that power generation efficiency is lowered due to moisture absorption after drying. In addition, there is also a problem that spontaneous ignition occurs as the moisture is resorbed to the dried coal and the stored coal is lost. Morimoto et al., Energy Fuels , 2009, 23, 4533; DJ Allardice et al., Fuel , 2003, 82, 661]

Therefore, one of the most important problems to be solved in order to promote the use and dissemination of low-grade coal is to develop a technology that maintains calorific value and suppresses spontaneous ignition by preventing water from being resorbed to the dried low-carbon I will. Among the technologies that can be used to solve these problems, the most popular technology is to remove intrinsic moisture of coal by heating low-grade coal in a high pressure atmosphere using a high temperature organic solvent. However, this technology has the disadvantage that the organic solvent must be separated and recovered, and the process is relatively complicated and another energy cost is required. Therefore, there is an urgent need for a technology for suppressing water resorption of dry coal.

On the other hand, among the issues that are being issued globally as energy sources, the use and dissemination of new and renewable energy sources can be used to cope with global warming and climate change by reducing carbon dioxide emissions compared to fossil fuels such as oil and coal. It is because it is attracting attention as energy source. However, in Korea, when renewable energy sources such as solar or wind power are used for power generation or heating, breakthroughs in use and dissemination have been limited due to differences in generation cost compared to fossil fuels.

In Korea, the new renewable energy mandatory quota system [Renewable Portfolio Standard (RPS)] has been introduced since 2012. It is true that this is a burden for energy providers.

Therefore, in order to promote the use and dissemination of renewable energy and comply with the mandatory quota system of renewable energy, it is essential to develop and use renewable energy sources. Among them, biomass has no concern of depletion and technology as energy source. It is easy to develop and is of interest compared to other renewable energy sources.

In particular, as the renewable energy source, the production of electric power by burning biomass-derived materials such as wood pellets or wood chips has a high weight policy, and thus it is expected to increase demand because it can be mixed with coal and used as fuel. It is very difficult to receive wood pellets or wood chips stably.

Therefore, in order to secure supply stability of biomass fuel that must be mixed for the purpose of reducing CO ₂ emission of coal power plants, there is a demand for a breakthrough technology development that can use various biomass-derived materials for coal power generation. ED Larson et al., Energy Environ. Sci. , 2010, 3, 28]

In addition, recently, the environmentally friendly and high efficiency has been in the spotlight, and the coal is wet gas to produce a combustible gas (syngas), the electricity production through IGCC (Integrated Gasification Combined Cycle), through the CTL (Coal To Liquid) Synthetic oil production and the manufacture of various chemicals are possible, which requires maintaining a high concentration of coal slurry.

On the other hand, in the case of wet coal gasification, there remains a problem that it is difficult to manufacture a high concentration of slurry. The fractionation bed coal gasification is divided into dry fractionation layer and wet fractionation layer. Wet fractionation layer gasification has the advantages of lower equipment construction cost, simpler structure and operation method, and easy supply of coal slurry at high pressure. However, in spite of these various advantages, in the case of wet, since the water is additionally included in the manufacture of the slurry used as the wet gasification raw material, the calorific value of the coal slurry is lower than that of the dry using the coal, thereby lowering the gasification efficiency. . Therefore, despite efforts to produce a high concentration of coal slurry to compensate for this disadvantage, low coal is known to be a more serious problem because of the high water content of low coal slurry.

The present invention has been made in view of the above problems, the first object of the present invention is to coat the hydrophilic surface present in the low-carbon coal with a carbon component to modify the hydrophobic by drying the coal inherent, even after drying is suppressed The present invention provides a high calorific value hybrid coal mixed with natural carbon and artificial carbon components, and a method for producing the same, to efficiently utilize low-grade coal.

In addition, the second object of the present invention is to produce a renewable energy source by using a biomass-derived material as a carbon component in coating hydrophilic surfaces existing in coal such as high-grade coal as well as low-grade coal with hydrophobic properties. To promote the use and dissemination of

In addition, a third object of the present invention is to produce a high calorific value hybrid coal in which natural carbon components and artificial carbon components of coal are mixed into any one of a dispersion medium selected from water / alcohol, water / surfactant, or water / alcohol / surfactant. It is to provide a method for producing a high concentration hybrid coal slurry by addition and a high concentration hybrid coal slurry produced thereby.

The present invention for achieving the object as described above provides a high calorific value hybrid coal in which the natural carbon component and artificial carbon component of the coal is mixed by coating the hydrophilic surface present in the coal with the carbon component of the biomass-derived material .

The hydrophilic surface is characterized in that it is a ash surface of coal.

The hydrophilic surface is characterized in that the fixed carbon and volatile surface of the coal having -COOH (carboxyl group), -NH ₂ (amine group), -OH (hydroxyl group) functional group.

The coal is characterized in that any one selected from peat, lignite, sub-bituminous coal, bituminous coal, anthracite coal.

The coal is characterized in that the natural water content of raw coal of 5 to 70% by weight.

The coal is characterized in that the intrinsic moisture content of the dried coal of less than 5% by weight.

The biomass-derived material is characterized in that the sugar cane stock or molasses.

The biomass-derived material may include a saccharide obtained by enzymatic decomposition of a saccharide or starch system converted from lignocellulosic cellulose.

The biomass-derived material is characterized in that any one selected from monosaccharides, disaccharides or polysaccharides.

The monosaccharide is characterized in that any one selected from glucose, fructose or galactose.

The disaccharide is characterized in that any one selected from sucrose, maltose or lactose.

The polysaccharide is characterized in that any one selected from starch or lignocellulose.

The high calorific value of the high calorific value hybrid coal is characterized in that more than 4000 kcal / kg.

The present invention also includes the steps of i) kneading coal with a solution of biomass-derived material to form a paste, and ii) simultaneously drying and carbonizing the biomass-derived material by injecting the paste into a carbonization furnace. The present invention provides a method for producing a high calorific value hybrid coal coated with a biomass-derived carbon component on a hydrophilic surface of coal.

The biomass-derived material in step i) is characterized in that the addition of 0.1 to 50% by weight relative to the weight of coal.

The solution of the biomass-derived material in step i) is characterized in that using water or an organic solvent.

In preparing the biomass-derived material solution using the water or organic solvent, the weight ratio of water or organic solvent / coal is maintained in the range of 0.1 to 5.

The organic solvent in step i) is characterized in that any one selected from methanol, ethanol or propanol.

In step ii), the drying and carbonization of the biomass-derived material is performed at 150 to 900 ° C. for 0.1 to 10 hours.

In addition, to improve the penetration of the biomass-derived material to the hydrophilic surface of the coal, characterized in that it comprises the step of aging the paste at room temperature, atmospheric pressure before performing step ii).

The aging time of the paste aging step is characterized in that 5 to 240 hours.

The biomass-derived material is characterized in that it performs the function of a binder for hybrid coal molding.

In addition, the present invention as another solution for controlling the moisture resorption rate of the high calorific value hybrid coal to a lower state i) kneading coal with a solution of biomass-derived material to form a paste; ii) aging the paste at room temperature and atmospheric pressure for 5 to 240 hours; iii) predrying the aged paste; And iv) subjecting the pre-dried paste to a carbonization furnace to simultaneously dry and carbonize the biomass-derived material, wherein the biomass-derived carbon component is coated on the hydrophilic surface of the coal using a two-step drying process. A method for producing a high calorific value hybrid coal and a high calorific value hybrid coal produced thereby are provided.

In addition, the present invention includes the step of forming a hybrid coal slurry by adding the hybrid coal obtained by the above production method to any one of a dispersion medium selected from water / alcohol, water / surfactant or water / alcohol / surfactant, It provides a method for producing a high concentration hybrid coal slurry.

The water / alcohol dispersion medium is characterized in that the weight ratio of alcohol / water is 0.01 ~ 0.99.

The alcohol of the water / alcohol dispersion medium is characterized in that one selected from methanol, ethanol or propanol.

The surfactant may be formed of CWM1002 (formaldehyde condensate of sodium naphthalene sulfonate), CWM1001 (polymer sulfonate), Na-CMC (carboxymethyl cellulose), Na-DBS (Alkylbenzene sulfate), Na-LS (alkylsulfate sodium salt), NP1020 (alkylphenol ethyleneoxide (NP1020) 10)), NP1060 (alkylphenol ethyleneoxide (50)), CA1053 (casteroil ethyleneoxide (50)), ATLOX4913 (methyl methacrylate graft copolymer), characterized in that any one selected from cetyltrimethylammonium brimide or cetyltrimethylammonium chloride.

The present invention also provides a high concentration hybrid coal slurry prepared by the method for producing a high concentration hybrid coal slurry.

The biomass-derived hybrid coal produced by the present invention is carbonized by infiltrating the hydrophilic surface of the coal with a hydrophobic carbon, and the high calorific value of the dry coal is significantly suppressed by the adsorption of moisture. It can be maintained as it can be used as a differential fuel for power plants, and thus can improve the power generation efficiency compared to mixing low-grade coal containing natural water, there is an effect that can reduce the CO ₂ emissions of the power plant. In addition, additional CO ₂ emissions can be reduced by the biomass added to produce hybrid coal. In addition, it is possible to relieve the burden on the energy provider to secure biomass fuel due to the new renewable energy mandate.

In addition, according to the present invention, a biomass-derived hybrid coal having a hydrophobic carbon coated with a hydrophobic carbon on the hydrophilic surface of the biomass-derived material is carbonized with water / alcohol, water / surfactant or water / alcohol / surfactant. The high concentration hybrid coal slurry prepared by adding to any one of the dispersion medium selected from among the significantly higher than the slurry made of coal or dry coal, the coal concentration of the slurry.

Therefore, when the high concentration hybrid coal slurry prepared by the present invention is applied to the wet fractionation bed gasification, the gasification performance such as coal conversion rate, cold gas efficiency, etc. can be increased, and thus CO ₂ emission of the gasification process can be expected to be reduced. Since it is possible to manufacture a high concentration slurry using low-grade coal having a high water content, the competitiveness of the wet gasifier for the dry gasifier of a complicated structure may be further strengthened. In addition, since the biomass-derived material is added in an amount of 0.1 to 50% by weight relative to the weight of coal when the high calorific value hybrid coal is used to prepare the high concentration hybrid coal slurry, the high concentration hybrid coal slurry of the present invention is used in a wet coal gasifier. additional reduction of the effects of the CO ₂ is fundamentally the biomass used is expected when used as a.

1 is a conceptual diagram of a high-concentration hybrid coal slurry in which low-grade coal according to the present invention is advanced using a biomass-derived material.

2 is a hydrophobic experiment photograph of hybrid coal and simple dry coal prepared from Example 1 and Comparative Example 1. FIG.

3 is a result of measuring the viscosity of the hybrid coal slurry according to Examples 1 and 2 and the dried coal and raw coal slurry according to Comparative Examples 1 and 2.

4 is a change in slurry calorific value with respect to the viscosity change of the hybrid coal slurry according to Example 1 and the dried coal and raw coal slurry according to Comparative Examples 1 and 2.

5 is a result of hydrophobicity evaluation (contact angle measurement) of hybrid coal and simple dry coal produced from Example 3 and Comparative Example 3.

6 is a pore size distribution diagram of hybrid coals prepared from Example 3 and Comparative Example 4. FIG.

By using the biomass-derived material according to the present invention, by coating the hydrophilic surface present in the lower coal with a carbon component and modifying it with hydrophobicity, natural carbon and artificial carbon components inherent to coal are suppressed after adsorption of moisture. The technology for upgrading low coal by producing the hybrid high calorific value hybrid coal will be described in detail.

In addition, a high calorific value hybrid coal mixed with natural carbon components and artificial carbon components of coal according to the present invention is added to any one of a dispersion medium selected from water / alcohol, water / surfactant, or water / alcohol / surfactant to have a high concentration. A method for producing a hybrid coal slurry will be described in detail with the accompanying drawings.

As shown in FIG. 1, as one embodiment of the present invention, i) kneading coal with a solution of biomass-derived material to form a paste, ii) putting the paste into a carbonization furnace to dry the biomass-derived material And a high calorific value hybrid coal coated with a biomass-derived carbon component on a coal hydrophilic surface from the step of simultaneously carbonizing.

The coal hydrophilic surface is a ash surface of coal, and is a fixed carbon and volatile surface of coal having a -COOH (carboxyl group), -NH ₂ (amine group), and -OH (hydroxyl group) functional group.

The coal may be any one selected from peat, lignite, sub-bituminous coal, bituminous coal or anthracite coal. In the present invention, to produce a low calorie coal, a high calorific value hybrid coal coated with a biomass-derived carbon component on the coal hydrophilic surface, the hybrid coal production method of the present invention may be a high-grade coal.

In addition, the coal is characterized in that the high water content of raw coal or 5 to 70% by weight of the dry coal of the high water content or less.

On the other hand, the biomass-derived material is characterized in that the sugarcane stock solution or molasses, the biomass-derived material may be any one selected from monosaccharides, disaccharides or polysaccharides.

The reason for coating the carbon component using the biomass-derived material is because of the saccharides contained in the biomass-derived material. It may also contain sugars obtained by enzymatic digestion of starch systems such as corn.

Monosaccharide is selected from glucose, fructose or galactose, disaccharide is selected from sucrose, maltose or lactose, polysaccharide is characterized in that any one selected from starch or lignocellulose.

The high calorific value of the hybrid coal is characterized in that more than 4000 kcal / kg.

The biomass-derived material is preferably formed by adding 0.1 to 50% by weight relative to the weight of coal using water or an alcohol-based organic solvent selected from methanol, ethanol or propanol. If the amount of biomass-derived material added to the weight of coal is less than 0.1% by weight, the amount of biomass-derived material penetrating into the hydrophilic surface of coal is insignificant, so that the hydrophilic surface of coal cannot be sufficiently coated so that the hydrophilic surface of coal is hydrophobically modified. If it is difficult, if it exceeds 50% by weight, it is difficult to obtain paste properties, resulting in poor workability.

In preparing the biomass-derived material solution using the water or organic solvent, the weight ratio of water or organic solvent / coal is maintained in the range of 0.1 to 5. If the weight ratio of water or organic solvent / coal is less than 0.1, it is difficult for the biomass-derived material to penetrate into the hydrophilic surface of coal, making hydrophobic modification of the hydrophilic surface difficult. If the weight ratio of water or organic solvent / coal is 5 or more, drying and There is a disadvantage in that energy consumption increases in the carbonization process.

When the paste is formed, the formed paste is added to a carbonization furnace to simultaneously perform a drying and carbonization process, preferably at 0.1 to 10 hours at 150 to 900 ° C. If the temperature of the drying and carbonization process is less than 150 ° C. and less than 0.1 hour, it is difficult to completely dry organic solvents such as water, but the biomass-derived material is not completely carbonized. Efficiency is hampered by an increase in the energy costs of doing so.

In addition, to improve the penetration of the biomass-derived material to the hydrophilic surface of the coal, characterized in that it comprises the step of aging in a room temperature, atmospheric pressure before performing step ii).

The aging time of the aging step is characterized in that 5 to 240 hours.

On the other hand, the biomass-derived material used to modify the hydrophilic surface of the coal to hydrophobic in the present invention improves the moldability by performing the function of the binder in the hybrid coal molding.

In another aspect, the present invention provides a method for controlling the moisture resorption rate of the high calorific value hybrid coal to a lower state, i) kneading coal with a solution of biomass-derived material to form a paste; ii) aging the paste at room temperature and atmospheric pressure for 5 to 240 hours; iii) predrying the aged paste; And iv) subjecting the pre-dried paste to a carbonization furnace to simultaneously dry and carbonize the biomass-derived material, wherein the biomass-derived carbon component is present on the hydrophilic surface of the coal using a two-step drying process. Coated high calorific value hybrid coal is produced.

In another embodiment, the paste is aged, the paste is aged for 5 to 240 hours at room temperature and atmospheric pressure to improve penetration of the biomass-derived material into the hydrophilic surface of the coal, and the dried paste is preliminarily dried. It may be referred to as a characteristic technical idea.

On the other hand, as in the present invention, the hybrid coal is homogeneous because the biomass-derived material penetrates into the pores of the coal and is physically chemically combined with the coal, as compared with the conventional non-uniform combustion characteristics by simply physically mixing the biomass and the coal. In addition to exhibiting combustion characteristics, the degree of resorption of moisture after drying is lowered by blocking the pores of coal. Therefore, the more effectively the pores of coal are blocked, the less the resorption rate of water.

Therefore, through the step of pre-drying the paste of coal and biomass-derived material adopted in the present invention to prevent the pores of the coal more effectively to reduce the volume of the pores to significantly reduce the moisture resorption rate of the hybrid coal undergoing subsequent drying and carbonization process It can be reduced.

The predrying is preferably carried out at 50 ~ 150 ℃ 0.1 ~ 24 hours. If the pre-drying temperature is less than 0.1 ° C for 50 ° C, it is difficult to completely dry organic solvents such as water, but the pore-filling effect of blocking pores of coal is insignificant. If it exceeds 150 ° C for 24 hours, Another increase in energy costs hinders efficiency.

As another embodiment of the present invention, a method for producing a high calorific value hybrid coal using the two-stage drying process has the same conditions as those of the above-described embodiment of the present invention except for introducing a preliminary drying process. .

The high calorific value hybrid coal manufactured using the two-stage drying process shows a takeover calorific value of 4,000 kcal / kg or more.

In addition, in the present invention, as shown in the conceptual diagram shown in FIG. 1, the high calorific value of the hybrid coal produced according to the embodiment of the present invention is selected from water / alcohol, water / surfactant or water / alcohol / surfactant. By adding to the dispersion medium, a high concentration hybrid coal slurry was produced. When water / alcohol was used as the dispersion medium, the weight ratio of alcohol / water was set to 0.01 to 0.99.

If the weight ratio of alcohol / water is less than 0.01, it is difficult to form a slurry, and if the weight ratio of alcohol / water exceeds 0.99, the wet gasification reaction does not occur, so it is preferable to maintain the weight ratio of alcohol / water in the range of 0.01 to 0.99.

In addition, for the purpose of improving dispersibility, a dispersion medium of water / surfactant may be used by using a surfactant instead of alcohol, and the surfactant used at this time is usually used for the purpose of improving dispersibility in slurry production. Any of these may be used, but in preparing the hybrid coal slurry according to the present invention, CWM1002 (formaldehyde condensate of sodium naphthalene sulfonate), CWM1001 (polymer sulfonate), Na-CMC (carboxymethyl cellulose), Na-DBS (Alkylbenzene sulfate), Alkylsulfate sodium salt (Na-LS), alkylphenol ethyleneoxide (10) (NP1020), alkylphenol ethyleneoxide (50) (NP1060), CA1053 (casteroil ethyleneoxide (50)), ATLOX4913 (methyl methacrylate graft copolymer), cetyltrimethylammonium brimide or cetyltrimethylammonium chloride, etc. This is preferable, and the addition amount is suitably according to the kind of surfactant, if it is in the range in which a slurry is formed favorable. Clauses are possible.

In addition, a dispersion medium of water / alcohol / surfactant may be used to further improve the dispersibility of the slurry.

Hereinafter, specific embodiments will be described in detail.

(Production example of hybrid coal)

Sibeobu raw coal from Mongolia was prepared 100g of coal dried for 12 hours in an 110 ℃ oven. An aqueous sucrose solution was prepared in which 25 g of sucrose was dissolved in 100 g of water. Sucrose aqueous solution was added to the dried sibeobu coal to knead, and a composite of the sibeobu coal and the sucrose aqueous solution was obtained in the form of a paste.

The obtained paste was placed in a reactor at 250 ° C. under a nitrogen atmosphere, and then dried and carbonized to prepare hybrid coal.

Table 1 below shows the industrial analysis results and calorific value of Sibeobu raw coal and hybrid coal according to the preparation example.

Table 1

Analysis item / sample name	Industrial analysis (wt%)				High calorific value (kcal / kg)	Low calorific value (kcal / kg)
Analysis item / sample name	Moisture (M)	Volatile Powder (VM)	Ash	Fixed Carbon (FC)	High calorific value (kcal / kg)	Low calorific value (kcal / kg)
Shibeobu Wontan	35.10	25.23	15.78	23.89	4,420	3,990
Hybrid coal	3.25	37.27	21.40	38.08	4,770	4,560

As shown in Table 1, the hybrid coal had a lower calorific value (when considering the latent heat of high moisture content) of 570 kcal / kg and a higher calorific value of 350 kcal / kg, compared to Sibeobu raw coal. It can be seen that the calorific value is improved when manufactured with hybrid coal. In addition, since hybrid coal additionally contains artificial carbon formed from biomass-derived materials, the fixed carbon was found to be about 14.2 wt% higher than that of Sibeobu raw coal. More importantly than the fact that hybrid coal has a higher calorific value than Sibero coal, it is possible to maintain the calorific value of the hybrid coal for a long time because moisture is not resorbed.

Meanwhile, in the coal field, a viscosity and concentration measuring method through slurry production is generally used as a method for measuring the amount of water adsorbed on coal. In general, the coal concentration of the slurry at an arbitrary viscosity is inversely proportional to the amount of water adsorption of coal. It is known that the lower the coal concentration in the slurry, the higher the water adsorption amount of coal. Therefore, the moisture of the hybrid coal of Examples 1 and 2 and the Sibeobu dry coal and Sibeobu raw coal of Comparative Examples 1 and 2 below. Adsorption amount could be confirmed by measuring the viscosity of the slurry prepared in the following examples, the results can be seen from FIG.

Example 1

500g of Sibeobu raw coal from Mongolia was prepared. A molasses aqueous solution in which 32 g of molasses was dissolved in 280 g of water was prepared. A molasses aqueous solution was added to the Sibeobu raw coal and kneaded to obtain a composite of Sibeobu raw coal and molasses aqueous solution in the form of a paste.

Samples of 75 micrometers or less are collected by sieveing the prepared hybrid coal with 200 mesh. Hybrid coals of 75 micrometers or less are added to the ethanol / water mixed solvent having a weight ratio of 0.1, so that the concentration of the hybrid coal is 28%, 30%, 32%, 34%, 36%, 38% by weight based on dry coal. %, 40% by weight, and 42% by weight of slurry were prepared, respectively.

Example 2

Slurry was prepared in the same manner as in Example 1 except that the paste obtained in Example 1 was placed in a reactor at 350 ° C. under a nitrogen atmosphere, and dried for 5 hours to produce hybrid coal.

Comparative Example 1

Sibeobu coal of Mongolia was prepared 500g of dried coal at 110 ℃ oven for 12 hours. The sibeobu dry coal was sieveed at 200 mesh to collect only samples of 75 micrometers or less. Sibeobu dry carbon of 75 micrometers or less is added to the ethanol / water mixed solvent having a weight ratio of 0.1, so that the concentration of coal is 28%, 30%, 32%, 34%, 36%, 38% based on the dry coal. Slurry amounts of 40% by weight, 42% by weight were prepared, respectively.

Comparative Example 2

A slurry was prepared in the same manner as in Comparative Example 1 except that the sibeobu dry coal of Comparative Example 1 was replaced with the sibeobu raw coal.

Example 3

Sibeobu raw coal from Mongolia was prepared 500g of coal dried for 12 hours in a 105 ℃ oven. A molasses aqueous solution in which 32 g of molasses was dissolved in 280 g of water was prepared. A molasses aqueous solution was added to the dried Sibeobu coal to knead to obtain a composite of Sibeobu coal and molasses aqueous solution in the form of a paste.

The obtained paste was aged at room temperature and atmospheric pressure for 24 hours. The aged paste was subjected to predrying at 105 ° C. for 12 hours. The pre-dried paste was placed in a reactor at 250 ° C. under a nitrogen atmosphere to prepare hybrid coal by drying and carbonizing for 2 hours.

Comparative Example 3

Sibeobu raw coal from Mongolia was simply dried in an oven at 105 ° C. for 2 hours to obtain 500g of Sibeobu coal.

Comparative Example 4

The step of performing the preliminary drying step of Example 3 was omitted, and the aged paste was put in a reactor at 250 ° C. under a nitrogen atmosphere to prepare hybrid coal by drying and carbonizing for 2 hours.

Experimental Example 1

Simple experiments were performed to evaluate the hydrophobicity of hybrid coal and simple dry coal before the coal slurry was prepared from Example 1 and Comparative Example 1. Add 3 g of hybrid coal to 50 g of water and stir vigorously using spatular. For comparison, add 3 g of Sibeobu dry carbon to 50 g of water, and prepare a sample with vigorous stirring using spatular. The photograph of each sample after stirring is shown in FIG.

As shown in FIG. 2, the Sibeobu simple dry coal was easily dispersed while absorbing water due to amphipathy, but in the case of hybrid coal after reforming, most of them were floating on the water despite strong stirring due to hydrophobicity. It could be observed. From this, it was confirmed that the hydrophilic pore surface of the hybrid coal was hydrophobically modified, and the resorption of moisture was suppressed.

In order to determine the coal concentration of the hybrid coal slurry prepared according to Examples 1 and 2 of the present invention, the viscosity of the coal slurry was measured, and the slurry prepared from Sibeobu simple dry coal and raw coal of Comparative Examples 1 and 2 was used. The viscosity was also measured, and the results are shown in FIG. 3.

As shown in Figure 3, the coal concentration at the same slurry viscosity was higher in the order of hybrid coal> dry coal> raw coal, in particular, in the case of the hybrid coal according to the present invention, the coal concentration of the slurry was markedly high. When the coal slurry concentration was 3000 cP, the hybrid coal prepared in Example 1 showed a slurry concentration of 9.4 wt% higher than that of Sibeobu coal and 5.5 wt% higher than that of Sibeobu dry coal. The hybrid coal prepared in Example 2 showed a slurry concentration of 8.1 wt% as compared to Sibeobu raw coal and 4.2 wt% as compared to Sibeobu dry coal. This is because the water added in the process of preparing the slurry is coated with the carbon component of the biomass-derived material and is inhibited from penetrating into the hydrophobicly modified hydrophilic surface. In addition, since the artificial carbon component of the biomass-derived material filling the hydrophilic surface, such as the ash hole, reduces the effective volume in which water can be absorbed, the absorption of water is reduced.

Figure 4 shows the slurry calorific value change behavior according to the slurry viscosity change for each sample of Example 1, Comparative Examples 1 and 2. It was confirmed that the hybrid coal of Example 1 showed an extremely high slurry calorific value under the same viscosity condition as compared to the Sibeobu dry coal of Comparative Example 1 and the Sibeobu raw coal of Comparative Example 2. Therefore, when the hybrid coal slurry is used for the wet fractionation layer gasification, the gasification performance can be improved than when raw coal or dry coal slurry is used.

Experimental Example 2

In order to evaluate the hydrophobicity of hybrid coal and simple dry coal prepared in Example 3 and Comparative Example 3, a disk of each coal sample was prepared and a contact angle measurement of water droplets on the surface of the disk was performed. Hybrid coal and simple dry coal are sieved with a powder of 100 μm or less and compressed to 50 atm to produce a disc having a diameter of 3 cm. Water droplets were dropped on the disks of the hybrid coal and the simple dry coal prepared in Example 3 and Comparative Example 3 to measure the contact angle with the disk surface, and the photograph is shown in FIG. 5. As shown in FIG. 5, the contact angle of the simple dry coal is 78.1 degrees, whereas the contact angle of the hybrid coal is significantly increased to 132.3 degrees. The larger the contact angle of water, the higher the hydrophobicity of the sample. In general, when the contact angle is more than 120 degrees, it is determined that the hydrophobicity of the sample is high. From this, it was confirmed that the hydrophilic pore surface of the hybrid coal was hydrophobically modified, and it can be seen that the resorption rate of water from the hydrophobicity of the hybrid coal can be significantly lowered.

In addition, the industrial analysis results and calorific value of Sibeo raw coal and hybrid coal according to Example 3 are shown in Table 2 below.

TABLE 2

Analysis item / sample name	Industrial analysis (wt%)				Takeover calorific value (kcal / kg)	True calorific value (kcal / kg)
Analysis item / sample name	Moisture (M)	Volatile Powder (VM)	Ash	Fixed Carbon (FC)	Takeover calorific value (kcal / kg)	True calorific value (kcal / kg)
Shibeobu Wontan	34.44	25.22	18.91	21.43	2,786	2,466
Hybrid Coal (Example 3)	1.14	33.89	30.14	34.83	4,083	3,914

As shown in Table 2, the hybrid coal of the present invention had a true calorific value (when considering the latent heat of high moisture content) of about 1450 kcal / kg, compared to Sibeobu raw coal, and the takeover calorific value generally used in power plants. It can be seen that about 1300 kcal / kg is higher, and the calorific value is greatly improved when manufactured with the hybrid coal of the present invention. In addition, since the hybrid coal of the present invention additionally contains artificial carbon formed from the biomass-derived material, the fixed carbon was found to be about 13.4wt% higher than that of Sibeobu coal. More important than the fact that the hybrid coal produced in the present invention has a higher calorific value than the Sibeo raw coal, the resorption degree of moisture is significantly reduced, so that the calorific value of the hybrid coal can be maintained for a long time.

6 is Graph showing the pore size distribution of the hybrid coal prepared from Example 3 using a two-step drying step and Comparative Example 4 using a one-step drying step without the pre-drying step by introducing a predrying step of a paste containing a biomass-derived material. to be.

As can be seen in Figure 6 the pore volume in the mesopore region of the hybrid coal of Comparative Example 4 is larger than the pore volume of the hybrid coal prepared from Example 3. In other words, in the hybrid coal, it is possible to further reduce the pore volume by maximizing the pore-filling effect of blocking pores by introducing a preliminary drying process of the paste.

Experimental Example 3

The coal prepared in Example 3 and Comparative Examples 3 and 4 was soaked in excess water to allow water to be adsorbed into the pores while stirring for 10 minutes, and then filtered for 20 minutes to remove external moisture and weighed. Moisture resorption rate was calculated as follows.

Moisture resorption rate (wt%) = (C _wet -C _dry ) / C _dry * 100

[C _wet is the weight of coal before water removal, C _dry is the weight of coal after water removal]

Table 3 shows the measurement results of Experimental Example 2.

TABLE 3

Sample	Shibeobu simple dry coal (Comparative Example 3)	First Step Drying Process Hybrid Coal (Comparative Example 4)	Two stage drying process hybrid coal (Example 3)
Moisture Resorption Rate (wt%)	44.55	34.93	30.74

As can be seen in Table 3, the hybrid coal produced from Example 3 using the two-step drying process had a resorbency rate of 30.74 wt% of water, and the moisture resorption rate of Sibeobu raw coal, which was simply dried at 105 ° C of Comparative Example 3 It can be seen that the re-adsorption rate of the hybrid coal prepared from Comparative Example 4 using 44.55 wt% and the one-step drying process showed a significantly lower value than 34.93 wt%.

Therefore, the hybrid coal manufactured by using the two-stage drying process of the present invention can maintain the high calorific value of the dry coal as it is, can be used as a fine fuel for power plants, and the generation efficiency compared to mixing low-grade coal containing intrinsic moisture There is an advantage that can be improved.

Claims

A high calorific value hybrid coal in which the hydrophilic surface of the coal is coated with the carbon component of the biomass-derived material.
The high calorific value hybrid coal according to claim 1, wherein the hydrophilic surface is an ash surface of coal.
The high calorific value hybrid according to claim 1, wherein the hydrophilic surface is a fixed carbon and volatile surface of coal having a -COOH (carboxyl group), -NH 2 (amine group), and -OH (hydroxyl group) functional group. Coal.
The method of claim 1, wherein the coal is a high calorific value hybrid coal, characterized in that any one selected from peat, lignite, sub-bituminous coal, bituminous coal or anthracite coal.
The method of claim 1, wherein the coal is a high calorific value hybrid coal, characterized in that the natural water content of 5 to 70% by weight of raw coal.
The high-calorie hybrid coal of claim 1, wherein the coal is dry coal having a high moisture content of 5 wt% or less.
The method of claim 1, wherein the biomass-derived material is a high calorific value hybrid coal, characterized in that the sugar cane stock or molasses.
The high calorific value hybrid coal according to claim 1, wherein the biomass-derived material is a saccharide obtained by enzymatic decomposition of a saccharide or starch system converted from lignocellulosic cellulose.
The method of claim 1, wherein the biomass-derived material is a high calorific value hybrid coal, characterized in that any one selected from monosaccharides, disaccharides or polysaccharides.
The high calorific value hybrid coal according to claim 9, wherein the monosaccharide is one selected from glucose, fructose or galactose.
The high calorific value hybrid coal according to claim 9, wherein the disaccharide is one selected from sucrose, maltose or lactose.
10. The method of claim 9, wherein the polysaccharide is high calorific value hybrid coal, characterized in that any one selected from starch or lignocellulose.
The high calorific value hybrid coal of claim 1, wherein the high calorific value of the high calorific value hybrid coal is 4000 kcal / kg or more.
i) kneading coal with a solution of biomass-derived material to form a paste; ii) simultaneously injecting the paste into a carbonization furnace to dry and carbonize the biomass-derived material. Method for producing a high calorific value hybrid coal coated with a biomass-derived carbon component.
15. The method of claim 14, wherein the biomass-derived material is added in an amount of 0.1 to 50% by weight based on the weight of coal.
15. The method of claim 14, wherein the solution of biomass-derived material uses water or an organic solvent.
The method of claim 16, wherein the organic solvent is any one selected from methanol, ethanol or propanol.
The method of claim 16, wherein the weight ratio of water or organic solvent / coal in the preparation of a biomass-derived material solution using water or an organic solvent is 0.1-5.
15. The method of claim 14, comprising the step of aging the paste at room temperature, atmospheric pressure before performing step ii).
20. The method of claim 19, wherein the aging time of the aging step is 5 to 240 hours.
The method of claim 14, wherein the drying and carbonization of the biomass-derived material is performed at 150 to 900 ° C for 0.1 to 10 hours.
15. The method of claim 14, wherein the biomass-derived material performs the function of a binder for forming hybrid coal.
i) kneading coal with a solution of biomass derived material to form a paste;

ii) aging the paste at room temperature and atmospheric pressure for 5 to 240 hours;

iii) predrying the aged paste; And

iv) adding the pre-dried paste to a carbonization furnace to simultaneously dry and carbonize the biomass-derived material, wherein the biomass-derived carbon component is coated on the hydrophilic surface of the coal using a two-step drying process Method for producing high calorific value hybrid coal.
24. The method of claim 23, wherein the high calorific value hybrid coal takes over the calorific value of 4,000 kcal / kg.
The method of claim 23, wherein the preliminary drying of step iii) is performed at 50 to 150 ° C for 0.1 to 24 hours.
A high concentration comprising the step of adding a hybrid coal prepared by the method of claim 14 or 23 to a dispersion medium selected from water / alcohol, water / surfactant or water / alcohol / surfactant to form a hybrid coal slurry. Method for producing a hybrid coal slurry.
27. The method of claim 26, wherein the water / alcohol dispersion medium has a weight ratio of alcohol to water of 0.01 to 0.99.
27. The method of claim 26, wherein the alcohol of the water / alcohol dispersion medium is one selected from methanol, ethanol or propanol.
The method of claim 26, wherein the surfactant is formaldehyde condensate of sodium naphthalene sulfonate (CWM1002), polymer sulfonate (CWM1001), carboxymethyl cellulose (Na-CMC), alkylbenzene sulfate (Na-DBS), alkylsulfate sodium salt (Na-LS), High concentrations characterized by any one selected from NP1020 (alkylphenol ethyleneoxide (10)), NP1060 (alkylphenol ethyleneoxide (50)), CA1053 (casteroil ethyleneoxide (50)), ATLOX4913 (methyl methacrylate graft copolymer), cetyltrimethylammonium brimide or cetyltrimethylammonium chloride Method for producing a hybrid coal slurry.
A high concentration hybrid coal slurry prepared by the method of claim 26.