KR20130013200A - Apparatus and method for upgrading low rank coal with high moisture upgrade coal - Google Patents

Abstract

PURPOSE: An apparatus and a method for upgrading a high-moisture and low-rank coal are provided to dry the low-rank coal at a lower temperature than an existing temperature, and to prevent oxygen absorption in storing the low-rank coal, which is molded into a dried coal powder, in a coal yard, thereby satisfying conditions of fuel for a standard thermal power plant using a pulverized coal. CONSTITUTION: An apparatus for upgrading high-moisture and low-rank coal comprises an oil vapor manufacturing part(100), which manufactures oil vapor, and an oil vapor drying part(110), which dries a low-rank coal using the oil vapor supplied from the oil vapor manufacturing part. The oil vapor manufacturing part is connected to an exhaust gas supply source in order to use exhaust gas as a heat source. The exhaust gas supply source is a normal power plant or an oxyfuel power plant. Oxygen concentration in the exhaust gas is less than 5%. The temperature of the exhaust gas is 150 to 250 Celsius degrees. The oil vapor manufacturing part includes an oil storage tank, an exhaust gas distributor, a nozzle, and a heater. The exhaust gas distributor is installed inside the oil storage tank, and is connected to the exhaust gas supply source in order to distribute the exhaust gas to the oil storage tank. The nozzle is respectively connected to the oil storage tank and the exhaust gas supply source so that the oil vapor formed in the oil storage tank can be discharged by the propulsion of the exhaust gas.

Description

Apparatus and method for upgrading low rank coal with high moisture upgrade coal}

The present invention relates to a high-grade device and method for using low grade coal having a water content of 30 to 60% as a fuel of a coal-fired power plant. More particularly, the present invention relates to the adsorption of hydrophobic (Hydrophobic) steam as a heat source. High moisture that can meet the conditions as a mixed fuel of pulverized coal power plant by drying low grade coal at a temperature of 150 ℃ or less lower than 400 ℃ and preventing spontaneous ignition by adsorption penetration and surface coating property of oil vapor. The present invention relates to an apparatus and a method for degrading low grade coal.

High-water high ash lignite (LRC: Low Rank Coal) is a high-grade technology (LRC → HRC) that dehydrates, dries, and stabilizes the fuel to bituminous coal (High Rank, High Rank Coal). define.

With high quality, lignite with 30% or more moisture becomes high quality coal with 10% or less moisture, Higher Heating Value (HHV) is from 4,500 kcal / kg or less to 6,500 kcal / kg or more, and the ignition temperature is 180 It becomes 210 degreeC or more at less than the temperature.

Lignite is juicy and highly ignitable. Figure 1 shows a structural model of coal, the left side shows a structural model of bituminous coal, the right side sub-bituminous coal. As shown in FIG. 1, since low grade coal has many pores and many hydrocarbons (peripheral hydrocarbons), the temperature rises due to the adsorption and desorption of moisture, and the oxygen functionality occupies a considerable amount in the volatile matters. The use of the group has been limited due to the high possibility of spontaneous combustion.

Water in the lower coal is divided into free water, interstitial water (pore water), surface water, bound water and the like. Much of the lower coal moisture is free water attached to the surface of the lower coal, the water present between the molecules of the lower coal and the inner water, and the bound water is chemically bound to the lower coal molecules. Free water and surface water are dried at 100 ± 5 ° C, but internal and bonded water are destroyed and dried at about 400 ° C. Therefore, it is difficult to maintain this high temperature up to low coal by conventional drying methods. .

In addition, the pores of coal during high-quality dehydration through low-grade coal drying are mainly oxygen oxidation reactors, for example, hydroxyl groups (-OH), carboxyl groups (-CH-OH-), carbonyl groups (Carbonyl group, -C = O) is generated. They eventually react with moisture and oxygen components when exposed to air and oxidize, raising the temperature inside the pores, causing spontaneous ignition. Therefore, in most high quality technologies, the solution of spontaneous ignition problem is essential for coal dried to a moisture content of 10% or less through a drying process.

Figure 2 shows a conceptual diagram of the BCB technology of Australia, a representative technology of the drying technology, the conventional low-grade coal drying and safety technology as shown in Figure 2, a fluidized bed drying method to dry by heating for 1 hour at a temperature of 400 ℃ or more, It has a disadvantage of low thermal efficiency and high molding pressure of dry coal, and also has a disadvantage of long-term storage in low coal. Above all, since the water removal rate is very low, in the range of 15 to 20%, it is used for lowering the water content of 30% coal to 25% water content.

An object of the present invention is a low grade coal having a water content of 30% or more, a calorific value of 4,500 kcal / kg or less, a ignition temperature of 180 ° C. or less, as a coal for power generation with a moisture content of 5% or less, a calorific value of 6,500 kcal / kg or more, and a ignition temperature of 230 ° C. or more. It is to provide a high quality device and method capable of high quality and significantly raising the firing temperature.

Another object of the present invention is to dry the low-grade coal to a lower temperature than conventional, high-grade device that can meet the conditions as fuel of the standardized pulverized coal power plant by preventing oxygen adsorption when stored in a low coal storage through the formation of dry coal powder And a method.

The present invention, in order to achieve the above object, an oil vapor production unit for producing an oil vapor; And it is connected to the steam production unit provides a high quality coal coalescing apparatus including a steam drying unit for drying the lower coal using the oil vapor supplied from the steam production unit.

In the present invention, the oil vapor production unit is connected to the exhaust gas supply, characterized in that the exhaust gas as a heat source.

In the present invention, the exhaust gas supply source may be a general power plant or a oxy-fuel plant, and in particular, the oxy-fuel plant is preferable.

In the present invention, the oxygen concentration in the exhaust gas is preferably 5% or less, the temperature of the exhaust gas may be 150 to 250 ℃.

Oil vapor production unit in the present invention is an oil storage tank for receiving oil and the oil is evaporated; An exhaust gas distributor installed inside the oil storage tank and connected to an exhaust gas source to distribute the exhaust gas to the oil storage tank; A nozzle connected to an oil storage tank and an exhaust gas source, respectively, to discharge oil vapor formed in the oil storage tank by propulsion of the exhaust gas; And it may include a heater installed on the outer wall of the oil storage tank.

In the present invention, the steam drying unit has a coal inlet and a coal outlet, and a drying chamber in which coal is dried; An oil vapor distributor installed inside the drying chamber and connected to the oil vapor production unit to distribute the oil vapor to the drying chamber; A microwave supplier installed in the drying chamber to irradiate microwaves; Vibration means installed on the lower portion of the drying chamber for vibrating the drying chamber; Vibration fluid plate installed in the drying chamber and made of a wave shape to induce the flow of coal by the vibration of the vibration means; And an exhaust gas inlet connected to the exhaust gas source and installed at a lower portion of the vibrating fluid plate.

In the vibrating fluidized plate of the steam drying unit according to the present invention, a plurality of pores are formed at the inlet side of the exhaust gas, and the plurality of pores preferably form an angle of ± 10 ° with the flow direction of the exhaust gas.

In addition, the present invention is a power plant boiler; An oil vapor production unit configured to manufacture oil vapor as a heat source of exhaust gas discharged from a power plant boiler; And it is connected to the steam production unit provides a high quality coal system including a steam drying unit for drying the lower coal by using the oil vapor supplied from the steam production unit.

The high quality coal coalification system according to the present invention includes a preheater installed at the rear end of the boiler and preheating air or oxygen supplied to the boiler by using exhaust gas discharged from the boiler as a heat source; And a condenser installed in a branch line branched from the exhaust gas treatment line and separating and removing water from the exhaust gas.

The preheater of the coal derating system according to the present invention includes a main preheater for preheating air or oxygen supplied to a boiler; And an exhaust gas preheater connected to the condenser to preheat the exhaust gas from which moisture has been removed.

The high-definition system of coal according to the present invention may further include a molding machine connected to the oil vapor drying unit for compression molding the dried coal.

In addition, the present invention comprises the steps of (a) preparing the vapor; And (b) drying the lower coal using oil vapor.

In step (a) of the high-definition method according to the present invention, it is preferable to produce oil vapor using exhaust gas as a heat source, and it is possible to transport oil vapor using exhaust gas as a propellant gas.

In step (b) of the high-definition method according to the present invention, at least some of the oil vapor is condensed and adsorbed on the coal surface, thereby dissociating the internal water between the coal molecules and the bound water bonded to the coal molecule surface.

In step (b) of the high-definition method according to the present invention, the exhaust gas can be used for the drying heat source and the coal flow, the microwave can be irradiated with coal, and the coal can be vibrated.

The high quality process according to the present invention comprises the steps of, before step (a), condensing exhaust gas to separate and remove moisture; And preheating the exhaust gas from which moisture has been removed, wherein the exhaust gas may be used as a heat source for preheating.

The high quality process according to the invention may further comprise, after step (b), compression molding the dried coal.

In the present invention, low-grade coal having a moisture content of 30% or more is dried to a temperature of 150 ° C. or less, which is 250 ° C. lower than 400 ° C. by applying steam vapor adsorption, microwave irradiation, and a coal-fired boiler or pure oxygen thermal power plant boiler exhaust gas heat source. Through the shaping of the dry coal powder, it is possible to meet the conditions as a fuel of the standardized pulverized coal power plant by preventing oxygen adsorption when stored in the low coal.

For low grade coal, there are external free and surface-attached waters that dry out in the range of 105 ± 5 ° C, whereas the pore water, capillary water, and internally held water that are chemically bonded inside the coal are 1 at temperatures above 400 ° C. Decompose and dry only after drying over time.

In the case of drying at a high temperature and high pressure of more than 400 ℃ as in the prior art, the combustion fuel value decreases due to the volatilization of volatiles in the drying process, there is a lot of unnecessary heat consumption during the drying process, due to the desorption of moisture on the surface of the dry coal There is a problem of spontaneous ignition caused by oxygen adsorption in the generated pores.

Therefore, in the present invention developed to improve such problems, the oil condensed through the contact with the high moisture low-grade coal infiltrate into the pore of the coal to increase the repulsive force with the combined water inside the coal to dissociate moisture Then, by drying through microwave irradiation, while drying at a low speed of about 20 minutes at a low temperature of less than 150 ℃ in a short time, it is possible to raise the ignition temperature to 230 ℃ or more.

1 shows a structural model of coal.
Figure 2 shows a conceptual diagram of the BCB technology of Australia, a typical technique of the drying technology.
3 is a graph showing a change in temperature in coal according to time and gas type.
Figure 4 shows the effect of the steam drying method on the combined moisture.
5 is a high-definition process chart of low grade coal according to the present invention.
6 is a cross-sectional view of the oil vapor production unit according to the present invention.
7 is a sectional view of an oil vapor drying unit according to the present invention.
8 is a side cross-sectional view of the porous vibrating fluid plate installed in the steam drying unit according to the present invention.
9 is a graph showing the measurement results of ignition temperatures of raw coal and high grade coal.
10 is a system diagram of the ignition temperature measuring apparatus.
11 is a graph showing changes in surface bond groups of raw coal and high grade coal.

The present invention is a heat source application technology for drying moisture, unlike the direct heating method such as electric furnace and fluidized bed dryer, in the case of a pure coal fired coal-fired power plant in preparation for the CO2 boiler and climate change agreement, and the general coal-fired power plant boiler It is characterized in that the exhaust gas discharged after combustion is applied as a heat source.

In addition, the present invention, after preheating the exhaust gas containing coal ash, nitrogen oxides and sulfur oxides in the exhaust gas, for example, the exhaust gas containing 95% CO ₂ to 200 ° C or more through heat exchange in the preheater, and the hot air exhaust gas for steam production It is used to decompose the combined water inside the low grade coal by supplying it to the heat source for drying high grade low grade coal.In terms of equipment, the drying efficiency is increased by using the optimal hot air perforated plate for even thermal contact. Characterized in that to prevent.

In the case of oxy-fuel boilers, unlike coal-fired power plants, since 98% or more of oxygen obtained by separating nitrogen gas from air is used as a raw material for combustion and the exhaust gas is recycled, the final exhaust gas is composed of combustion by-product when burning 1 kg of bituminous coal. In the case of CO ₂ is usually 95%, H ₂ O 2%, N ₂ 3%, when considering the leakage of O ₂ in the duct during operation, CO ₂ 95%, H ₂ O 2%, N ₂ 1%, O ₂ is distributed about 2%.

Therefore, in the case of pure oxygen power plant exhaust gas, since there is almost no active oxygen during drying, spontaneous ignition can be prevented even when the hot air gas is used as a heat source in the drying process or a hot air gas of 200 ° C. or higher as the primary air is supplied to the mill.

Particularly, in the case of carbon dioxide, as a result of spontaneous ignition experiment, as shown in FIG. 3, since the gas radiant heat transfer characteristic value (Gas emissivity) is high, the heat transfer rate to coal is higher than that of inert gas such as nitrogen or argon, and the temperature rise phenomenon due to spontaneous combustion occurs. Turned out to be absent.

That is, by condensing the exhaust gas discharged from the oxy-fuel boiler to remove moisture, when the concentration of carbon dioxide is concentrated to 95% or more and then supplied as a drying gas using an exhaust gas reheater, the drying efficiency is increased and the drying temperature is 200. Even if supplied above ℃, the problem of fire caused by spontaneous ignition can be completely solved.

In addition, in the case of producing steam using the exhaust gas of the pure oxygen boiler or coal-fired power plant boiler as a heat source, it is possible to prevent the explosion and ignition of the steam. When steam was produced using kerosene, by-product fuel and waste cooking oil as raw materials, it was found that the temperature of the pure oxygen flue gas was 200-250 ° C. and the coal-fired flue gas was 180-220 ° C. This could be confirmed by the oxygen concentration in the flue gas of coal-fired power plant.

Particularly, in the case of supplying steam as a heat source of high moisture low grade coal, as shown in FIG. By generating the repulsive force while exerting, it is possible to decompose the pore water and the bound water even at a low temperature of 150 ° C or lower.

That is, the oil vapor having a hydrophobic (Hydrophobic) becomes an oil during condensation, the present invention is applied to the technique using the difference in the solubility (Wettability) of the combined moisture having affinity of the coal carbon component and the hydrophilic (Hydrophilic).

On the other hand, the reaction mechanism uses adsorption characteristics through condensation of a certain amount of oil vapor to increase repulsion and repulsion between hydrophilic bonded water and carbon components of hydrophobic low grade coal. By increasing the surface tension and promoting decomposition with low grade coal.

As described above, since the application of oil vapor increases the decomposing power of the combined water such as the pore water and the capillary coupling water, even when the exhaust gas containing carbon dioxide is supplied at a temperature of 150 ° C. or lower, the combined water and the capillary coupling water are dried and ejected as steam. You can.

In addition, since the condensed oil is adsorbed in the pores, when the coal is compressed in the molding apparatus, the bonding force between the coals can be increased, and the adsorption of moisture and oxygen can be prevented, thereby greatly increasing the spontaneous ignition temperature.

On the other hand, when irradiating microwaves during vapor drying, coal components having a low dielectric constant (permeability) have a property of transmitting microwaves. On the other hand, internal moisture (gap water, bound water) such as polar solvent, which has a high transmittance, is evaporated while absorbing microwaves and releasing heat through its own molecular rotation.

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

5 is a schematic diagram of manufacturing high-grade coal for combustion of a coal-fired power plant using low-grade coal as a raw material according to the present invention. The high-grade system according to the present invention includes a boiler 10, a coal mill 20, and a preheater 30. ), Dust collector (40), blower (50), waste heat recovery system (60), desulfurization facility (70), stack (80), condenser (90), oil vapor production unit (100), oil vapor drying unit (110), dust collector 120, a molding machine 130, a low-charging cabinet 140, a powder mill 150, and the like.

The boiler 10 is composed of a general power plant boiler or a pure oxygen power plant boiler. The exhaust gas generated after combustion in the boiler 10 enters the preheater 30 through an economizer 20 in a state containing ash and air pollutants.

The preheater 30 includes a main preheater 31 for preheating the primary air A1 for supplying pulverized coal as fuel to the combustion boiler 10 and the secondary air A2 for combustion air, and increasing boiler efficiency; Characterized in that it consists of a drying exhaust gas preheating unit 32 for preheating the clean exhaust gas for low-grade coal drying and stabilization.

In general, the exhaust gas temperature discharged from the economizer 20 is 400 ° C. or more, and the exhaust gas temperature discharged from the rear end of the preheater 30 is lowered to about 150 ° C. through preheating of atmospheric air and drying air. On the other hand, the temperature of the atmospheric air (A) or high-purity oxygen (O) flowing into the combustion air is preheated in the atmospheric air preheater 31 to rise to 350 to 380 ℃ and then supplied to the primary and secondary air.

The exhaust gas preheater 32 occupies 5% of the total preheater 30 and serves to preheat the exhaust gas to be supplied to the oil vapor production unit 100 and / or the steam dryer 110, and the exhaust gas preheater 32. The temperature of the exhaust gas passing through (32) is maintained at 150 to 250 ° C.

Meanwhile, the exhaust gas cooled to about 150 ° C. by heat transfer in the preheater 30 is introduced into a dust collector 40, for example, an electric dust collector, and coal ash and the like are collected and removed from the dust collector 40.

Thereafter, the exhaust gas is absorbed through the blower 50 to the last residual heat in the waste heat recovery system 60, and then discharged through the stack 80 as clean air through the flue gas desulfurization facility 70, which is an air pollutant removing facility. do.

The main feature of the present invention is the use of clean exhaust gas that has undergone dust collection and desulfurization.

Clean exhaust gas has a composition of 25% CO ₂ , H ₂ O 5%, and N ₂ 70%. For pure oxygen boiler exhaust, CO ₂ 95%, H ₂ O 2%, and N ₂ 3%. .

Therefore, in order to remove about 5% of the moisture in the flue gas, a branch line is preferably formed between the desulfurization plant 70 and the stack 80 in the flue gas treatment line, and then a condenser 90 is attached to the branch line. Install.

As described above, the exhaust gas from which most of the moisture is removed through the condenser 90 is heated to 150 to 250 ° C. through heat exchange in the exhaust gas preheating unit 32 of the preheater 30. Used as a heat source of the oil vapor production unit 100 and the oil vapor drying unit 110.

The exhaust gas used in the oil vapor drying unit 110 is introduced into the dust collector 120, the dust collected by the dust collector 120 is transferred to the molding machine 130, and the gas is recycled to the condenser 90 to remove moisture. .

High moisture low grade coal (C) is, for example, 200 mesh passes through, is supplied to the upper end of the steam drying unit 110 is dried while moving slowly, then transferred to the molding machine 130 is compression molded and then low-charging 140 Stored in).

The stored high quality coal is finely ground in the mill 150 and then used as fuel of the combustion boiler 10. The fine powder scattered by the exhaust gas from the oil vapor drying unit 110 is collected through the dust collector 120 and re-transmitted to the molding apparatus 130.

As such, in order to dry low grade coal having a water content of 30% or more to high quality coal for coal fired combustion with a moisture content of 10% or less, high moisture low grade coal (C) having passed through 200 mesh is used as a raw material, By applying the coal-fired power plant exhaust gas or oxygen-oxygen-fired power plant exhaust gas having an oxygen concentration of 5% or less recovered from the preheater 30 as a heat source, the surface water of the low-grade coal (C) is removed, After dissociating the internally bound coal through coal, the non-degradable water such as pore water, capillary coupling water, internally retained water, etc., which is decomposed and dried at 400 ° C. or higher, is dried at 150 ° C. or lower, and 5% moisture and 2 4 to 4% of the level of dry coal may be manufactured using high quality coal of 1.11 g / cm 3 or more through the molding machine 130 to prevent spontaneous ignition in the low coal 140.

6 is a cross-sectional view of the oil vapor production unit according to the present invention, the oil vapor production unit 100 is the exhaust gas inlet pipe 101, exhaust gas distributor 102, injection port 103, oil storage tank 104, heater 105, And a connecting pipe 106, a nozzle 107, a nozzle inlet 108, a nozzle outlet 109, and the like.

Oil (L) is stored in the oil storage tank 104, and oil (L) for steam production may include boiler kerosene, by-product fuel (haixin), and waste cooking oil. At this time, the oil storage tank 104 should maintain a temperature of about 150 ℃, for this purpose, a heater 105 may be installed on the outer wall of the oil storage tank 104.

The exhaust gas preheated to about 200 ° C. in the preheater 30 is used as a heat source for producing steam, and the exhaust gas is introduced through the exhaust gas inlet pipe 101 and supplied to the inside of the oil storage tank 104 through the exhaust gas distributor 102. .

The exhaust gas distributor 102 is disposed in the lower portion of the oil storage tank 104 in the longitudinal direction and / or the width direction so as to evenly inject the exhaust gas into the oil storage tank 104, and the plurality of injection holes formed at regular intervals Has 103.

The exhaust gas of about 200 ° C. supplied through the internal distributor 102 promotes volatilization and decomposition of boiler kerosene, by-product fuel or waste cooking oil to generate oil vapor.

The generated vapor is introduced into the nozzle 107 through the connecting pipe 106, and the exhaust gas is also introduced into the inlet 108 of the nozzle 107. At this time, the exhaust gas flowing into the nozzle 107 is used as a propellant gas and serves to transport oil vapor. That is, the exhaust gas is used as a heat source for producing steam in the vapor production unit 100, and is used as a propulsion gas for transporting vapor. In another aspect, exhaust gas must be injected instead of general air in order to prevent fire caused by oil vapor and static electricity.

The oil vapor is discharged together with the exhaust gas to the outlet 109 of the nozzle 107 and then transferred to the oil vapor drying unit 110.

7 is a detailed view of the steam and microwave drying method and the flow reaction type steam drying unit of the core components of the present invention, the steam drying unit 110 is a drying chamber 111, coal inlet 111a, exhaust gas inlet 111b, gas Outlet 111c, coal outlet 111d, drying chamber connection 111e, vapor distributor 112, injection port 112a, microwave feeder 113, temperature sensor 114, vibrating fluid plate 115, pores 115a ), A vibration spring 116, a vibration feeder 117, a support 118 and the like.

The drying chamber 111 may be composed of an upper drying chamber and a lower drying chamber formed long in the longitudinal direction, and the upper and lower drying chambers may be integrally formed through the connecting portion 111e.

The drying chamber 111 is a coal inlet 111a for supplying low-grade coal at one upper end, an exhaust gas inlet 111b for supplying exhaust gas at one lower end, and a gas outlet for discharging oil, exhaust gas, steam, dust, etc. at the upper end of the other side ( 111c), and the other side of the lower end has a coal discharge port 111d through which the coal is discharged.

An oil vapor distributor 112 is installed at an upper portion of the drying chamber 111, and the oil vapor distributor 112 is long over the longitudinal direction and / or the width direction of the drying chamber 111 so that the oil vapor may be evenly sprayed on the drying chamber 111. It is arranged, and has a plurality of injection holes 112a formed at regular intervals.

The microwave supply 113 is installed at least one inside and / or outside of the drying chamber 111, and acts as a heat source for drying coal along with oil vapor and exhaust gas.

At least one temperature sensor 114 is installed inside and / or outside the drying chamber 111 to measure the temperature of the drying chamber 111 and may be associated with the microwave supply 113. In detail, the temperature may be controlled by controlling the microwave supply 113 while monitoring the temperature inside the coal through the temperature sensor 114.

Vibration fluid plate 115 is installed in the drying chamber 111, and made of a wave (Wave type) serves to induce the flow of coal by the vibration of the vibration means.

Vibration means is installed in the lower portion of the drying chamber 111 to vibrate the drying chamber 111 to generate the flow of coal and the flow of coal, the vibration feeder 117 and the vibration spring 116 to generate vibration, etc. It is configured and supported by the support 118.

The high moisture low grade coal (C) is introduced into the upper part of the drying chamber 111 through the coal inlet 111a using the one passed through the 200 mesh, and the oil vapor is supplied to the upper part of the drying chamber 111 through the oil vapor distributor 112. Injecting, the exhaust gas is supplied to the lower portion of the drying chamber 111 through the exhaust gas inlet (111b).

Oil vapor primarily acts as a heat source for coal drying and serves to dry the surface water of coal. At the same time, the oil vapor is condensed through heat transfer with the coal surface and is converted into oil, adsorbing on the coal surface and the pores, thereby generating a repulsive force with the coal-bonded water and pore water.

Flue gas also acts primarily as a heat source for coal drying, and also serves to induce the flow of coal while passing through the vibrating fluid plate 115.

The microwave feeder 113 also acts as a heat source to facilitate binding water and pore water drying.

In this way, oil vapor, flue gas, microwave, and the like act in combination to allow drying of coal even at a low temperature of 150 ° C or lower.

In addition, the coal flow by the complex action of the exhaust gas, vibrating fluid plate 115, vibrating means 116, 117, etc., it is possible to facilitate the drying of the coal more smoothly, and at the same time the coal outlet inlet 111a Can be moved toward 111d.

8 is a cross-sectional view of a vibrating fluid plate according to the present invention, the vibrating fluid plate 115 is formed with a plurality of pores 115a for the introduction of the exhaust gas, the pores (115a) is the propulsion direction (V) of the wave shape It is installed in the lower portion as a reference, and is formed to be in an angle of ± 10 ° with the flow direction of the flue gas and coal, preferably parallel to, for preventing backflow and smooth contact. The size of the pores 115a is smaller than the size of the coal so that coal does not leak. Through the pores 115a, the exhaust gas passes through the vibratory fluidizing plate 115 to promote the flow of coal.

An apparatus and method for obtaining high quality coal from low grade coal according to the present invention will be described with reference to Examples.

[Example]

The oil vapor production apparatus is manufactured as shown in FIG. 6, but the oil storage tank 104 has a diameter of 30 cm and a height of 20 cm, and a 30 kW hot wire feeder is installed on the outer wall as a heater 105.

The steam drying apparatus is manufactured as shown in FIG. 7, but the drying chamber 111 has a length of 300 cm, a width of 30 cm, and a height of 30 cm, and includes a coal inlet 111a, a gas outlet 111c, and a steam distributor 112. The inlet area was designed to be 2inch × 2inch, and the microwave supply 113 used a 2.45 GHz, 2 kW, 220 V, single phase, and a temperature sensor 114 using a stainless steel shielded thermocouple, but the temperature sensor 114 ) The installation part diameter was 1 cm, and two vibration feeders 117 having a capacity of 0.45 kW were attached to both sides in order to uniformly vibrate the drying chamber 111.

The vibrating fluid plate 115 is made in a wave shape using a Teflon material, as shown in FIG. 8, but the maximum distance 115 cm and 5 cm from the bottom of the drying chamber 111, the minimum distance 115 c and 2 cm and the wave width 115 d. ) Was made in 5.5 cm, the pores (115a) was formed in the vertical direction with a size of 5 mm diameter and 1 cm left and right intervals on the left side of the wave shape.

The experimental conditions are as follows.

◇ coal

Indonesian coal 1 kind

Total moisture content: 36.4%

Coal size: 200 mesh

◇ Steam production department

Oil vapor manufacturing raw materials: boiler by-product fuel (Hisin)

Preheated flue gas supply to the flue gas distributor 102: 0.06 to 0.12 m 3 / min

Supply amount of the propellant gas (exhaust gas) supplied to the nozzle 107: 0.12 to 0.24 m 3 / min

◇ Steam Drying Unit

-1st drying method: flue gas and vapor contact

-1st drying temperature: 110 ~ 130 ℃

Oil vapor flue gas injection rate: 0.18 ~ 0.36 ㎥ / min

Preheat flue gas injection rate: 0.54 ~ 0.72 ㎥ / min

Preheat flue gas injection rate: 1 ~ 2 m / s

-2nd drying method: microwave irradiation and binding water molecule rotation

-2nd drying temperature: 120 ~ 150 ℃

Second drying time: 5 ~ 20 minutes

Low grade coal throughput: 20 kg / hr

◇ Molding Equipment

Pressure: 24T / ㎠

Operating pressure: 15 tons / ㎠

The properties of low grade coal and high grade coal used in the experiment are shown in Table 1.

Low grade coal High quality coal Total moisture (wt% ar) 36.4 4.5 ~ 5.2 Ash (wt% db) 3.0 3.20-3.15 Volatilization (wt% db) 50.1 47.06-48.12 Fixed Carbon (wt% db) 42.9 43.21-43.26 Fuel cost (-) 0.86 0.92-0.93 Calorific value (kcal / kg ar) 4,253 6,900-6,910 Calorific value (kcal / kg db) 6,291 7,140-7,210 C (wt% daf) 69.76 71.03-71.52 H (wt% daf) 4.82 4.17-4.59 N (wt% daf) 1.15 1.13-1.16 S (wt% daf) 0.12 0.14-0.16 O _diff (wt% daf) 24.13 23.03-23.06 Particle Size (mm) 2 to 5 - ar: as received basis
db: dry basis
daf: dry ash free basis

For low grade coal, the moisture content is about 36%, and the calorific value is 6,291 kcal / kg (dry), higher than that of anthracite, but lower than coal for coal-fired power plants (6,500 kcal / kg). The fuel cost is 0.86, which is similar to the sub-bituminous series, and it can be confirmed that it is suitable for the specification of thermal power plant when the moisture is dried below 10%.

Further, by-product fuel 1 (Hycin) for producing steam was composed of a density of 0.8091 g / cm 3, a flash point of 46.5 ° C., 0.05% of sulfur, a viscosity of 1.01 mm 2 / S, and a residual carbon amount of 0.01%.

On the other hand, as shown in Table 1, the produced high-grade coal showed a very low water content of less than 5.2%, and the heat content was very high, more than 7,140 kcal / kg. In particular, the fuel cost was greatly improved to 0.92 or more. From the physical properties of Table 1, it was found to be suitable as a raw material for burning coal-fired power plants.

As a result, industrial and elemental analysis of high-quality dry coal through oil vapor, preheated flue gas drying and microwave heat source supply, it is suitable for the combustion of coal-fired power plant as shown in Table 1, water content is about 5%, oil residue is It was about 2%.

9 is a graph showing the measurement results of ignition temperatures of the raw coal and the high grade coal, the left side of which is a high moisture low grade raw coal, and the right side which is an optimum dry high grade coal.

In order to measure the ignition temperature, the raw coal and the high-grade coal powder were compressed to 15 ton / cm 2 by a molding apparatus having a capacity of 24 ton / cm 2 and then spontaneous ignition temperature was measured. The spontaneous ignition measurement experiment was performed with an elevated temperature experimental apparatus. The temperature increase apparatus was composed of a thermostat, a thermocouple, a temperature controller, a recorder and a sample container as shown in FIG. The thermostat is a hot air circulating thermostat with an internal volume of 90 L (45 cm × 45 cm × 45 cm), which is an improved thermostat, and is equipped with a Sirocco fan to maintain a constant temperature distribution. Was forced to circulate, and two heaters of 1,000 W were used to heat the thermostat. A fan was installed at the exhaust port of the upper part of the thermostat so that the fan was operated by a relay switch when the internal temperature was higher than the set temperature. Thermocouples are two sets of Chromel-Alumel thermocouples used for controlling and measuring the ambient temperature and for measuring the center temperature of the sample. The former is installed at the center of the wall of the sample vessel and the thermostat, and the latter is located at the center of the sample vessel. The diameter of the thermocouple was 0.35 mm. The temperature control window (EC-5600 manufactured by Konics) allows you to control the compensated temperature through the cold junction by controlling the ambient temperature by setting the program. Current values were controlled and the operation of the upper fan was controlled on-off using a relay switch.

In the experimental method, 50 g of coal or powder of a sample was put in a cell and air was supplied at 30 cm 3 / min while heating the internal air at a temperature increase rate of 5 ° C./min. The temperature was measured. The temperature at which the air temperature in the oven and the temperature in the sample were equal was defined as the cross point temperature (CPT) and defined as the ignition temperature.

As a result, as shown in FIG. 9, the average ignition temperature measured six times in the case of the raw coal was very low as 176.3 ° C., whereas in the case of coal produced through a high quality process, the result was very high as 241.8 ° C. FIG.

However, as shown in Table 2, the product characteristics depending on whether the steam injection, microwave irradiation, and molding for each process was found to be greatly affected by the performance of the microwave irradiation and the vapor adsorption process. That is, in the case of the product produced during the vapor drying and microwave irradiation, it was possible to make a high quality coal having a ignition temperature of 241 ° C. or higher without molding, and the ignition temperature was increased to 250 ° C. during compression for low coal storage in coal-fired power plants. Appeared.

Table 2 shows the properties and the ignition temperature of high quality coal by experimental process conditions.

High quality
Tanjong Fair performance Product Specifications Ignition temperature
(℃) Vapor
Injection microwave
Research Molding Dry coal 1 ○ ○ ○ -5% moisture
-2% oil remaining
Density 1.11 g / cm 3 250 Dry coal 2 ○ ○ × -5% moisture
-2% oil remaining
Density 0.65 g / cm3 241 Dry coal 3 × ○ ○ Moisture 7.5%
0% oil remaining
Density 1.11 g / cm 3 225 Dry coal 4 ○ × ○ -15% moisture
-2% oil remaining
Density 1.05 g / cm 3 210

In the case of coal produced by drying the coal steam flue gas or pure oxygen boiler flue gas as a heat source and dried using high-quality microwaves, the moisture removal rate (35% → 5%) is 85% or more, Through infiltration and adsorption of dry carbon pores of oil vapor, as shown in FIG. 11, the concentration of oxygen functional groups on the surface of the coal was lowered and moisture and oxygen adsorption were prevented during storage of low coal.

11 is a graph showing surface changer changes of the raw coal and the high grade coal, the left side being a high moisture low grade coal raw material, and the right side being an oil vapor dry high quality coal. X-ray photoelectron spectroscopy (XPS) analysis showed that in the case of vapor drying, the concentration of oxygen functional groups (CO, C = O, OC = O), which causes spontaneous ignition on the surface of dried coal, is due to the surface coating of oil residue and pore adsorption. It was confirmed to decrease.

In the case of drying at a high temperature and high pressure of more than 400 ℃ as in the prior art, the combustion fuel value decreases according to the volatilization of the volatile components in the drying process, there are a lot of unnecessary calories consumption in the drying process and the drying time is too long, it was difficult to commercialize .

In the present invention, by applying a heat source of coal-fired power plant flue gas or oxy-fuel boiler flue gas heat source instead of the existing high temperature and high pressure heating method and increasing the hydrophobicity of the combined moisture and hair shaft water through the adsorption of steam, drying time by drying the microwave, It is possible to shorten the drying temperature to 150 ° C. or less and to improve the ignition temperature to 230 ° C. or more.

In addition, according to the present invention it is possible to solve problems such as economical degradation and excessive power consumption of the conventional low-grade coal drying apparatus, combustion problems that occur when using high-quality coal.

Korea imported about 80 million tons of high grade bitumen coal in 2007, and is the second largest importer of coal after Japan. Of the 80 million tons, approximately 57 million tons are used for power generation only. Therefore, in the case of Korea, which imports a huge amount of coal in the future, the present invention can be applied for more than 50 years due to import substitution effect.

The high quality coal produced through the high quality of the low grade coal according to the present invention can be applied for coal and mixed combustion in the thermal power plant.

In addition, the present invention can be applied to coal-fired industries such as Indonesia, China, Australia, where all coal-fired power plants (including domestic and foreign power plants) using coal as fuel, and a large amount of low grade coal are buried.

At present, domestic coal-fired power plants are seeing a surge in coal prices, which contributes to an increase in power generation costs. In case of replacing the imported coal from power plants through the high quality of low grade coal, which is currently 1/4 to 1/3 the price of bituminous coal, the annual import replacement effect of 1 trillion won (based on the current 20% power plant) is expected. It is also applicable to the domestic steel industry and cogeneration plants.

The present invention is a technology for producing high grade coal (HRC) of the same grade as bituminous coal by high-quality with respect to lignite (LRC) which is not used due to high moisture and spontaneous ignition. Of the additional expenses of KRW4.3 trillion, which are increasing due to import costs, the company can reduce KRW 1 trillion annually.

Table 3 shows the coal usage forecast, technology development and import reduction forecast.

Cogeneration Coal-fired power plant Income reduction Current usage (based on grenades) 5 million tons 57 million tons - Estimated Use by 2020 10 million tons 75 million tons - 2015 (5,000 ton / day)
(1.5 million tons / year factory production start) 15% replacement 2% replacement 100 billion won / year 2020 (15 million tons / year)
(Expanded 10 million tons / year plant) 100% replacement 20% replacement KRW 1 trillion / year

The present invention can be prepared for oil shocks, and the price fluctuations are severe and can reduce the import price of coal, which occupies more than 70% of the unit cost, the potential growth is very high.

In addition, as shown in Table 4, the world reserves of low grade coal is 4747 billion tons, so importing and using low grade lignite can lead to a decrease in power generation costs.

Imported coal of existing power plant Low grade coal Sum World 509491 474720 984211 North America 116707 139770 256477 Latin America 7839 13735 21574 Europe 41664 80368 122032 Former Soviet Union 97476 132707 230178 Africa 61162 250 61412 Middle East 193 - 193 Australia 47300 43100 90400 China 62200 52300 114500 India 72733 2000 74733 Indonesia 770 4450 5220

10: boiler
20: cutter
30: preheater
31: preheating part
32: exhaust gas preheating unit
40: dust collector
50: blower
60: waste heat recovery system
70: desulfurization equipment
80: stack
90: condenser
100: vapor production unit
101: flue gas inlet pipe
102: exhaust gas distributor
103: nozzle
104: oil storage tank
105: burner
106: connector
107: nozzle
108: nozzle inlet
109: nozzle outlet
110: vapor drying unit
111: drying chamber
111a: coal inlet
111b: flue gas inlet
111c: gas outlet
111d: coal outlet
111e: drying chamber connection
112: vapor distributor
112a: nozzle
113: microwave feeder
114: temperature sensor
115: vibrating fluid plate
115a: pore
116: vibration spring
117: vibrating feeder
118: support
120: dust collector
130: molding machine
140: low magazine
150: differential

Claims (23)

A vapor production unit for manufacturing oil vapor; And
A high quality coal coalification apparatus including a vapor drying unit for drying low-grade coal using the oil vapor supplied from the oil vapor production unit.
The method of claim 1,
An oil vapor production unit is connected to an exhaust gas supply source, and the exhaust gas is a heat source.
The method of claim 2,
The flue-gas supply source is a coal decentralization device, characterized in that the general power plant or a oxy-fuel plant.
The method of claim 2,
High-grade coal coal, characterized in that the oxygen concentration in the exhaust gas is 5% or less.
The method of claim 2,
The temperature of the flue gas is 150 to 250 ℃ high-definition apparatus of coal.
The method of claim 1,
Oil vapor manufacturing department
An oil storage tank for receiving oil and evaporating oil;
An exhaust gas distributor installed inside the oil storage tank and connected to an exhaust gas source to distribute the exhaust gas to the oil storage tank;
A nozzle connected to an oil storage tank and an exhaust gas source, respectively, to discharge oil vapor formed in the oil storage tank by propulsion of the exhaust gas; And
And a heater installed on the outer wall of the oil storage tank.
The method of claim 1,
Steam drying unit
A drying chamber having a coal inlet and a coal outlet, where coal is dried;
An oil vapor distributor installed inside the drying chamber and connected to the oil vapor production unit to distribute the oil vapor to the drying chamber;
A microwave supplier installed in the drying chamber to irradiate microwaves;
Vibration means installed on the lower portion of the drying chamber for vibrating the drying chamber;
Vibration fluid plate installed in the drying chamber and made of a wave shape to induce the flow of coal by the vibration of the vibration means; And
And a flue gas inlet connected to the flue gas source and installed below the vibrating fluidized plate.
The method of claim 7, wherein
The vibrating fluidized plate has a plurality of pores are formed on the exhaust gas inlet side, characterized in that the high quality coal coal.
9. The method of claim 8,
A plurality of pores are a high-quality coal coalescing device, characterized in that to form an angle of ± 10 ° with the flow direction of the exhaust gas.
Power plant boiler;
An oil vapor production unit configured to manufacture oil vapor as a heat source of exhaust gas discharged from a power plant boiler; And
A high quality coal coalescing system including a steam drying unit connected to the oil vapor producing unit and drying the lower coal using oil vapor supplied from the oil vapor producing unit.
The method of claim 10,
A preheater installed at the rear end of the boiler and preheating air or oxygen supplied to the boiler by using the exhaust gas discharged from the boiler as a heat source; And
A high quality coal coalification system installed in a branch line branched from an exhaust gas treatment line, and further including a condenser separating and removing water in the exhaust gas.
The method of claim 11,
Preheater
A main preheater for preheating air or oxygen supplied to the boiler; And
And a flue gas preheater connected to the condenser to preheat the flue gas from which moisture has been removed.
The method of claim 10,
And a molding machine connected to the oil vapor drying unit for compression molding the dried coal.
(a) preparing a vapor; And
(b) drying the lower coal by means of steam;
15. The method of claim 14,
(A) the high-quality coal production method characterized in that for producing the oil vapor using the exhaust gas as a heat source.
16. The method of claim 15,
In step (a), the exhaust gas as the propulsion gas as a high-quality coal transport method characterized in that for transporting oil vapor.
15. The method of claim 14,
At least part of the oil vapor in step (b) is condensed and adsorbed on the coal surface, thereby dissociating the internal water between the coal molecules and the bonded water bonded to the coal molecule surface.
15. The method of claim 14,
Method (b) to refine the coal, characterized in that for using the exhaust gas for drying heat source and coal flow.
15. The method of claim 14,
(b) the method of high-quality coal, characterized in that to irradiate the microwaves to coal.
15. The method of claim 14,
(b) vibrating coal in the step of high quality coal.
15. The method of claim 14,
before step (a)
Condensing exhaust gas to separate and remove moisture; And
The method of high quality coal further comprising the step of preheating the waste gas from which water was removed.
The method of claim 21,
A method for high quality coal, characterized by using exhaust gas as a heat source for preheating.
15. The method of claim 14,
after step (b)
The method of high quality coal further comprising the step of compression molding the dried coal.

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