AU2011270166B2 - Fuel treatment system, method for utilization of exhaust gas, and apparatus for utilization of exhaust gas - Google Patents

Abstract

It becomes possible to utilize a heat energy efficiently and utilize a poor-quality fuel actively. Disclosed is a fuel treatment system (1) comprising a database (DB) (2), a control unit (3), an adjustment means (4), and a drying treatment facility (300). In the treatment system (1), the temperature of a hot gas supplied from a hot gas supply facility is adjusted by the adjustment means (4) that is controlled by the control unit (3). The control in the control unit (3) is achieved on the basis of the information on the water content in the fuel and the information on the ignition temperature that have been stored in the DB (2). The hot gas of which the temperature has been adjusted is used for the drying treatment of a fuel in the drying treatment facility (300).

Description

DESCRIPTION FUEL TREATMENT SYSTEM, METHOD FOR UTILIZING OF EXHAUST GAS, AND APPARATUS FOR UTILIZING OF EXHAUST GAS 5 Technical Field [0001] The present invention relates to a fuel treatment system, a method for utilizing of exhaust gas, and an apparatus for utilizing of exhaust gas. 10 Background Art [0002] With the global increase of energy demand, it is increasingly necessary to use, as fuel used in a thermal power 15 facility, low-grade fuel such as low-grade coal having a high moisture content and biomass having high moisture content. It is expected that such a tendency will further increase. The low-grade coal, biomass and the like may hereinafter be collectively referred to as low-grade fuel. 20 [0003] The use of the low-grade fuel contributes to, however, lower fuel consumption rate of the thermal power facility. Particularly, in a coal using facility using pulverized coal, the coal is dried and crushed for combustion and then 25 introduced into a combustion furnace. Therefore, increase of the moisture amount in the coal used as fuel directly leads to deterioration of the fuel consumption rate. In addition, under an influence of a drying/crushing ability of a mill or the like, it is necessary to limit an amount of such the 30 low-grade fuel used therein. [0004] In order to avoid such a situation, a method of drying coal and a drying facility disclosed in Unexamined Japanese Patent Application Publication No. JP 10-281443 A (Patent 35 Document 1) listed below are known, for example. The drying facility in Patent Document 1 dries high-moisture coal as low-grade fuel in an atmosphere of 80 C to 150'C using combustion exhaust gas after passing through an exhaust gas temperature reduction device such as an air heater. [0005] 5 Meanwhile, in a coal-fired thermal power facility, generation of electricity is performed in a generator by combusting fuel such as pulverized coal or heavy oil, petroleum coke, in a combustion furnace such as a boiler to drive a steam turbine. Accordingly, when sulfur component 10 is included in these fuels, sulfur dioxide (SO 2 ) is included in exhaust gas after fuel is burned, and a portion of the S02 is oxidized to become sulfur trioxide (SO 3 ) . Sulfur dioxide

(SO

2 ) and sulfur trioxide (SO 3 ) may hereinafter be collectively referred to as "sulfur oxide" or "SOx." 15 [0006] The exhaust gas from the combustion furnace is normally treated by an exhaust gas treatment facility provided in a subsequent stage of the combustion furnace. The exhaust gas treatment facility comprises a denitrification device, a heat 20 recovery device, an electric dust collector, and a desulfurization device. In this exhaust gas treatment facility, when a temperature of the exhaust gas falls to below the sulfuric acid dew point, SO 3 in the exhaust gas condenses into sulfuric acid. Sulfuric acid contributes to the 25 corrosion of a flue and various types of facilities and devices or the like. [0007] For removal of SO 3 in the exhaust gas, a dry-type desulfurization process using ultrafine particles (see 30 Unexamined Japanese Patent Application Publication No. JP 5-269341 A (Patent Document 2), for example) and a method of removing sulfur oxide in the exhaust gas (see Unexamined Japanese Patent Application Publication No. JP 10-230130 A (Patent Document 3) , for example) are known. In the dry-type 35 desulfurization process disclosed in Patent Document 2, ultrafine particles of calcium oxide (CaO) are injected into an inside of a furnace generating the exhaust gas and/or into a flue to adsorb sulfur oxide. Moreover, in the removing method disclosed in Patent Document 3, S03 is treated, for example, by injecting ammonia between the heat recovery device 5 and the electric dust collector of the exhaust gas treatment facility. [Related Art Document] [Patent Document] [0008] 10 Patent document 1: Unexamined Japanese Patent Application Publication No. JP 10-281443 A Patent document 2: Unexamined Japanese Patent Application Publication No. JP 5-269341 A Patent document 3: Unexamined Japanese Patent Application 15 Publication No. JP 10-230130 A Summary of the Invention Problem to be Solved by the Invention [0009] In the conventional drying method as disclosed in 20 aforementioned Patent Document 1, the method uses a structure or a configuration in which it is impossible or difficult, respectively, to use heat energy from other facilities to further improve the heat efficiency, and provide effective use of the heat energy while minimizing factors expected to 25 affect the global warming. This is the problem of the method disclosed in Patent Document 1. [0010] In the conventional dry-type desulfurization process disclosed in aforementioned Patent Document 2, the ultrafine 30 particles are supplied to the inside of the combustion furnace from an ultrafine particle injecting inlet provided in the combustion furnace. However, it is difficult to remove acid substance with high efficiency, depending on where the injecting position is located. This is the problem of the 35 process disclosed in Patent Document 2. Further, in the conventional removing method disclosed in aforementioned Patent Document 3, since it is required to inject ammonia for treatment of SO 3 , it is difficult to remove SO 3 in the exhaust gas more cheaply and easily. This is the problem of the method disclosed Patent Document 3. Additionally, there is 5 increasing demand for more effectively providing the effective use of the heat energy of the exhaust gas and achieving efficient operation of the power generation facility with less problems. [0011] 0 A sulfur component (S component) is contained in high-moisture coal. High-moisture coal containing the S component combusted in the combustion furnace generates combustion exhaust gas containing SO 3 . The combustion exhaust gas is discharged from the combustion furnace. When 5 the combustion exhaust gas after passing through the air heater downstream of the combustion furnace is reduced in temperature below the sulfuric acid dew point, SO 3 in the exhaust gas condenses into sulfuric acid. It is thus concerned that sulfuric acid may contribute to the corrosion 0 of the flue and various types of facilities and devices or the like. There is also a problem in that such a sulfuric acid dew point issue makes it difficult to efficiently recover the heat of the exhaust gas. Here, the sulfuric acid dew point refers to a temperature at which SO 3 and moisture in the gas 5 start to react and condense into sulfuric acid. [00121 In view thereof, it is desirable to provide a fuel treatment system, a method for utilizing of exhaust gas, and an apparatus for utilizing of exhaust gas that may provide 0 the effective use of the heat energy and an established technology to positively use the low-grade fuel. It is another object of the present invention to provide a fuel treatment system, a method for utilizing of exhaust gas, and an apparatus for utilizing of exhaust gas that may treat SO 3 5 in the exhaust gas in a less expensive and easier manner, effectively provide the effective use of the heat energy of the exhaust gas, and efficiently operate the power generation facility with less problems. It is the object of the present invention to substantially overcome or ameliorate one or more of the above 5 disadvantages. Means for Solving the Problem [0013] The present invention provides a fuel treatment system 0 comprising: a drying process facility for drying fuel using heat gas; an adjustment device for adjusting a temperature of the heat gas and supplying the temperature-adjusted heat gas to the drying process facility; and 5 a control unit for controlling the adjustment device on the basis of data relating to a moisture amount and a temperature of a firing point of the fuel, wherein the fuel comprises coal or biomass, and the control unit controls drying so that the moisture 0 content of the fuel is 1.3 times or less of an equilibrium moisture content thereof. [00141 Further, one embodiment of the present invention may comprise: a boiler comprising a supply port for supplying 5 fuel, desulfurizing agent, and oxygen-containing gas and a discharge port for discharging exhaust gas after the combustion of the fuel using the oxygen-containing gas; a first heat-exchange device for exchanging heat between the exhaust gas discharged from the boiler and heat medium to heat 0 the heat medium using the exhaust gas; a second heat-exchange device for exchanging heat between water supplied to the boiler and heated heat medium after the heat exchange to heat the water using the heat medium; and a circulation path through which the heat mediumpasses, the circulation path circulating 5 between the first heat-exchange device and the second heat-exchange device.

[0015] The adjustment device may also control, for example, the flow rate of the heat gas. [0016] 5 Further, the adjustment device may comprise, for example, a heat exchanger. [00171 The heat exchanger may comprise, for example, a boiler water supply heater.

[0018] The adjustment device may further comprise, for example, a distribution device for distributing a heat gas supplied from the heat gas supply facility to the heat exchanger and 5 a bypass path, a mixing device for mixing heat gas discharged from the heat exchanger and heat gas passing through the bypass path. [0019] Preferably, the fuel treatment system further comprises, 10 a thermal power facility for generating electricity by combusting the fuel dried using the drying process facility, wherein thermal power facility comprises: a combustion furnace for combusting the fuel; and a desulfurizing agent injecting device provided to the combustion furnace for 15 injecting desulfurizing agent into the combustion furnace. [0020] In the first heat-exchange device, the circulation path in contact with the exhaust gas may have a surface temperature higher than a dew point of the exhaust gas. Note that the 20 temperature of the heat medium may be controlled by, for example, adjusting the flow rate of heat medium bypassing the second heat-exchange device. [0021] The boiler may comprise: a combustion furnace for 25 combusting fuel; a nose section provided in an upper side of an interior of the combustion furnace for narrowing an internal space of the combustion furnace, and wherein the supply port for supplying desulfurizing agent may be located in the vicinity of the nose section. 30 [0022] Preferably, the desulfurizing agent is calcium compound, and the calcium compound includes cement plant dust containing calcium carbonate (CaCO 3 ). [0023] 35 A method for utilizing of exhaust gas according to the present invention comprises: supplying coal in a drying process facility to dry the coal, the coal containing moisture and sulfur component, supplying the dried coal in a combustion furnace to combust the coal, and using heat of exhaust gas after the combustion, the method further 5 comprising, supplying desulfurizing agent in the combustion furnace to desulfurize the exhaust gas in the combustion furnace, and using heat of the desulfurized exhaust gas as a heat source for drying the coal. [00241 10 A method for utilizing of exhaust gas according to the present invention comprises supplying coal in a drying process facility to dry the coal, the coal containing moisture and sulfur component, supplying the dried coal in a combustion furnace to combust the coal, and using heat of exhaust gas 15 after the combustion, the exhaust gas containing ash content, the method further comprising the steps of: cooling the exhaust gas by an exhaust gas temperature reduction device; mixing the cooled exhaust gas and heat gas having a higher temperature than the cooled exhaust gas to generate mixed gas; 20 and supplying the mixed gas in the drying process facility, wherein the mixed gas is generated at an oxygen concentration of 10 vol% or less. [0025] A method for utilizing of exhaust gas according to the 25 present invention comprises, supplying coal in a drying process facility to dry the coal, the coal containing moisture, supplying the dried coal in a combustion furnace to combust the coal, and using heat of exhaust gas after the combustion, the method further comprising the steps of: supplying heat 30 gas discharged from a heat-using facility other than the combustion furnace to the combustion furnace as combustion air, the heat gas containing oxygen; and supplying the exhaust gas to the drying process facility, wherein the heat gas has an oxygen concentration of 15 vol% or more and a temperature 35 of 250'C or more. [0026] b The desulfurized exhaust gas may be supplied to the drying process facility to use heat of the exhaust gas as a heat source for drying the coal. [0027] 5 Heat is exchanged between the desulfurized exhaust gas and heat medium, and the heat medium heated by the exhaust gas is supplied to the drying process facility to use the heat medium as a heat source for drying the coal. [0028] 10 The desulfurized exhaust gas may be supplied to a dust collection device to remove ash content contained in the exhaust gas, and heat of the exhaust gas having the ash content removed may be used as a heat source for drying the coal. [0029] 15 The method may further comprise the step of removing the ash content from the cooled exhaust gas with a dust collection device, wherein the mixed gas may be generated by mixing the exhaust gas having the ash content removed and the heat gas. [0030] 20 Preferably, the exhaust gas has an oxygen concentration of 10 vol% or less. [0031] Preferably, the heat gas is heat gas discharged from a clinker cooler of a cement manufacture facility. 25 [0032] The method may further comprise the step of supplying desulfurizing agent in the combustion furnace to desulfurize exhaust gas in the combustion furnace. [0033] 30 The combustion furnace may be configured to have, in an upper side thereof, a nose section for narrowing an internal space of the combustion furnace, and the desulfurizing agent may be supplied in the vicinity of the nose section. [0034] 35 An apparatus for utilizing of exhaust gas according to the present invention comprises: a drying device for drying coal; a combustion device for combusting the dried coal; and a desulfurizing agent supply device for supplying desulfurizing agent to the combustion device, an exhaust gas supply path being provided connecting the drying device and 5 the combustion device, the exhaust gas supply path supplying the desulfurized exhaust gas to the drying device, and the drying device drying the coal using heat of the exhaust gas. Effects of the Invention [0035] 10 The present invention may provide the effective use of the heat energy and an established technology to positively use the low grade fuel. The present invention may also treat

SO

3 in the exhaust gas in a less expensive and easier manner, effectively provide the effective use of the heat energy of 15 the exhaust gas, and efficiently operate the power generation facility with less problems. BRIEF DESCRIPTION OF THE DRAWINGS [0036] 20 FIG. 1 is a functional block diagram of a fuel treatment system according to all embodiments of the present invention; FIG. 2 is a block diagram generally illustrating the entire fuel treatment system according to a first embodiment of the present invention; 25 FIG. 3 is a block diagram generally illustrating the entire fuel treatment system according to a second embodiment of the present invention; FIG. 4 is a block diagram generally illustrating the entire fuel treatment system according to a third embodiment 30 of the present invention; FIG. 5 is a block diagram generally illustrating the entire fuel treatment system according to a fourth embodiment of the present invention; FIG. 6 shows a structure of a combustion furnace of a 35 thermal power facility in a fuel treatment system according to a fifth embodiment of the present invention; LU FIG. 7 is a flowchart related to control of the fuel treatment system according to all embodiments of the present invention; FIG. 8 shows a structure of a combustion furnace of a 5 thermal power facility in a fuel treatment system according to a sixth embodiment of the present invention; FIG. 9 is a block diagram generally illustrating the entire fuel treatment system according to the sixth embodiment of the present invention; 10 FIG. 10 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a seventh embodiment of the present invention; FIG. 11 shows a detailed configuration of FIG. 10; FIG. 12 is a block diagram of the entire flow of a method 15 for utilizing of exhaust gas according to an eighth embodiment of the present invention; FIG. 13 shows a detailed configuration of FIG. 12; FIG. 14 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a ninth embodiment 20 of the present invention; FIG. 15 shows a detailed configuration of FIG. 14; FIG. 16 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a tenth embodiment of the present invention; 25 FIG. 17 shows a detailed configuration of FIG. 16; FIG. 18 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to an eleventh embodiment of the present invention. FIG. 19 is a block diagram of the entire flow of a method 30 for utilizing of exhaust gas according to a twelfth embodiment of the present invention; FIG. 20 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a thirteenth embodiment of the present invention; 35 FIG. 21 shows a detailed configuration of FIG. 20; FIG. 22 is a block diagram of the entire flow of a method II for utilizing of exhaust gas according to a fourteenth embodiment of the present invention; FIG. 23 shows a detailed configuration of FIG. 22; FIG. 24 is a block diagram of the entire flow of a method 5 for utilizing of exhaust gas according to a fifteenth embodiment of the present invention; FIG. 25 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a sixteenth embodiment of the present invention; 10 FIG. 26 shows a detailed configuration of FIG. 25; and FIG. 27 is a horizontal cross-sectional view of desulfurizing agent injecting positions of 0.8 M higher and 0.4 L lower in the combustion furnace according to an embodiment of the present invention. 15 Best Mode for Carrying Out the Invention [0037] With reference to the accompanying drawings, embodiments of a fuel treatment system, a method for utilizing 20 of exhaust gas, and an apparatus for utilizing of exhaust gas according to the present invention will be described below in more detail. [0038] [Entire Configuration of a Fuel Treatment System] 25 FIG. 1 is a functional block diagram of a fuel treatment system according to all embodiments of the present invention. With reference to FIG. 1, a fuel treatment system 1 comprises a database (DB) 2, a control unit 3, an adjustment device 4, and a drying process facility 300. In other words, the 30 treatment system 1 controls a temperature of heat gas supplied from a not-shown heat gas supply facility using the adjustment device 4. The adjustment device 4 is controlled by the control unit 3. [0039] 35 The control unit 3 may comprise a well-known computer. Specifically, the control unit 3 controls the adjustment ILZ device 4 on the basis of information from the DB2 to adjust a temperature of heat gas supplied from a not-shown heat gas supply facility. The temperature-adjusted heat gas is used to dry fuel in the drying process facility 300. Specific 5 examples of the heat gas supply facility and the heat gas comprise, for example, a hot air production furnace, heating furnace exhaust gas, boiler exhaust gas, clinker cooler exhaust gas, or the like. Among others, from the point of view of the effective use of the heat energy, the boiler 10 exhaust gas and the clinker cooler exhaust gas are preferably used. [0040] The fuel to be dried in the drying process facility 300 is, for example, fuel (coal) that contains moisture and thus 15 needs to be dried before combustion to improve the combustion efficiency during the combustion. Typically, the fuel is so-called low grade fuel, which contains high moisture, such as high-moisture coal and high-moisture biomass. [0041] 20 The high-moisture coal comprises sub-bituminous coal and brown coal. With respect to the moisture amount of the high-moisture coal, the total moisture content per unit mass is 20 to 60 mass %, for example. The high-moisture biomass comprises woody biomass such as wood waste, rice husk, forest 25 land remaining materials, and Palm Kernel Shell, and waste material biomass such as sludge, a residue, and livestock excreta, or the like. With respect to the moisture amount of the high-moisture biomass, the total moisture content is 20 to 70 mass%, for example. Although, in the following, 30 examples are considered where the low grade fuel is used as the fuel, the present invention is not necessarily limited thereto. The present invention may also be applied to fuel that may provide a sufficient combustion efficiency without the drying process. 35 [0042] The DB2 stores, for each type of low grade fuel, I -i information on the moisture amount and the temperature of a firing point IT ('C) of the low grade fuel. As necessary, the DB2 may store other information than the moisture amount and the temperature of the firing point IT. 5 [0043] Note that the information on the moisture amount may comprise, for example, information on the total moisture content TM (mass%) and the equilibrium moisture content EM (mass%) of the low grade fuel. The total moisture content 10 TM is, if the fuel is coal for example, the moisture contained in the coal before the drying process. Further, the equilibrium moisture content EM is the moisture content that reaches the equilibrium state in the atmosphere where the coal is exposed. The equilibrium moisture content EM depends on 15 the temperature and humidity of the atmosphere. [0044] Preferably, the drying process facility 300 dries the low grade fuel to a predetermined moisture amount. Specifically, the low grade fuel may be dried such that its 20 moisture content DM (mass%) after the drying process (hereinafter referred to as a post-drying moisture content DM) is a moisture content that is not below the equilibrium moisture content EM in the atmosphere and is as low as possible. 25 [0045] Meanwhile, in the drying process facility 300, it is required to perform the drying process such that the temperature GT of the heat gas to be used is a temperature slightly below the temperature of the firing point IT of the 30 fuel to be dried. A drying process at a temperature above the temperature of the firing point IT may result in fuel ignition in the drying process facility 300. [0046] Thus, the control portion 3 performs the following 35 operations to control the adjustment means 4 (see FIG. 7 described below).

(1) The type of fuel to be dried using the drying process facility 300 is identified. (2) The moisture amount and the temperature of the firing point IT of the fuel identified in the above (1) is acquired 5 from the database (DB) 2 that stores the information on the moisture amount and the temperature of the firing point IT. (3) From the temperature of the firing point IT acquired in the above (2), the temperature of the heat gas to be used in the drying process facility 300 is determined. 10 (4) The moisture amount of the fuel after the drying is determined. (5) From the moisture amount of the fuel before the drying in the above (2) and the moisture amount of the fuel after the drying in the above (4) , the heat amount necessary in the 15 drying process facility 300 is determined. (6) From the necessary heat amount in the above (5) and the temperature of the heat gas in the above (3), the amount of heat gas to be supplied to the drying process facility 300 is determined. 20 The control unit 3 and the adjustment device 4 will be described in more detail below. [0047] The control unit 3 identifies the type of fuel to be combusted in the drying process facility 300 on the basis of 25 input information input by a user through a not-shown input device or information automatically recognized by the drying process facility 300. Further, information on the moisture amount and the temperature of the firing point IT of the identified fuel is acquired from the DB2. Then, on the basis 30 of the moisture amount (for example, the total moisture content TM and the equilibrium moisture content EM) and the temperature of the firing point IT of the relevant identified fuel, the temperature GT( 0 C) and the post-drying moisture content DM of the heat gas to be used in the drying process 35 facility 300 is calculated. [0048] The temperature GT of the heat gas is given by GT = IT - a (a is a predetermined positive constant) . The post-drying moisture content DM is given by DM= EM D (B is a predetermined positive constant). 5 [0049] Further, information on the fuel mass WC (t/h) to be dried per unit time is identified on the basis of input information input by an operator or information automatically recognized by the drying process facility 300. Then, using the mass WC, 10 the heat amount QD (MJ/h) necessary per unit time in the drying process facility 300 and the flow rate VD (m 3 /h) of the heat gas necessary per unit time are calculated. Using these, the control unit 3 controls the adjustment device 4. [0050] 15 The adjustment device 4 may comprise, for example, a heat exchanger. In this case, the adjustment device 4 may also be configured to provide other devices with the difference (QT-QD) between the heat amount QT of the heat gas supplied from a not-shown heat gas supply facility and the above heat 20 amount QD. [0051] As described above, the treatment system 1 may determine the temperature of the heat gas introduced in the drying process facility 300 or the like on the basis of data held 25 in the DB2 that stores information on the properties of the fuel to be used. Thus, the adjustment device 4 may provide a drying process in which the temperature of the heat gas is below the temperature of the firing point IT of the fuel and the fuel is dried to an appropriate moisture amount 30 corresponding to the equilibrium moisture content EM. [00521 FIG. 7 is a flowchart related to control of the fuel treatment system according to all embodiments of the present invention. FIG. 7 illustrates the description in the above 35 (1) to (6). FIG. 7 also illustrates a preferable embodiment described below. Specifically, an embodiment is shown in which excess heat gas (corresponding to QP in FIG. 7) after the drying process facility 300 takes the necessary heat gas is used to preheat (heat) the boiler water supply. Thus, the heat energy may be used much more efficiently. The efficiency 5 of the boiler may also be improved. [0053] The treatment system 1 thus configured may provide the effective use of the heat energy of the heat gas from a heat gas supply facility and the positive use of the low grade fuel. 10 Now, specific examples of the treatment system 1 will be described below. [0054] [First Embodiment] FIG. 2 is a block diagram generally illustrating the 15 entire fuel treatment system according to a first embodiment of the present invention. Note that an example is considered here where coal is used as the low grade fuel. With reference to FIG. 2, the treatment system 1 comprises a coal thermal power station 100, a cement manufacture facility 200 as the 20 heat gas supply facility, and a coal drying process facility 300. [0055] The coal thermal power station 100 is a facility that uses and combusts coal to generate electricity. The coal 25 thermal power station 100 may be configured like well-known coal thermal power facilities. Specifically, the coal thermal power station 100 first grinds supplied coal to a predetermined size by a grinding device 101 comprising a vertical mill or the like. Then, a boiler 102 combusts the 30 coal at a temperature of, for example, about 1600 0 C. Coal of one or more different types of properties may be combined. [0056] Then, a heat energy generated by the boiler 102 drives a steam turbine, thus allowing an electric generator 103 to 35 generate and supply electricity. Note that a water supply heater 104 heats a water supply to the fuel combustion boiler .L / using steam from the steam turbine to improve the heat efficiency of the electric generator 103. [0057] Meanwhile, the exhaust gas generated in the boiler 102 5 may have nitrogen oxide removed by a denitrification device 105. The denitrified exhaust gas further has its temperature reduced by a heat recovery device 106. Heat recovered by the heat recovery device 106 may be used to increase, for example, the temperature of combustion air pumped into the boiler 102. 10 After passing through the heat recovery device 106, the exhaust gas is supplied to an electric dust collector 107. The electric dust collector 107 collects dust floating in the exhaust gas. [0058] 15 After passing through the electric dust collector 107, the exhaust gas has sulfur oxide removed by a desulfurization device 108. The exhaust gas is then discharged into the atmosphere as the exhaust gas. By the above process, the coal thermal power station 100 of the treatment system 1 according 20 to the first embodiment generates electricity. In the treatment system 1, before coal is supplied to the grinding device 101, the coal drying process facility 300 dries the coal. Here, specific examples of coal to be dried comprises so-called low grade coal or the like such as sub-bituminous 25 coal and brown coal. The coal is dried by the coal drying process facility 300 to the post-drying moisture content DM as described above. [0059] Here, the post-drying moisture content DM is a moisture 30 content that is not below the equilibrium moisture content EM of the coal and is as low as possible. Further, the equilibrium moisture content EM is here a moisture content that reaches an equilibrium state in the atmosphere to which the coal is exposed (such as a drying process facility outlet, 35 a storage silo, or the air atmosphere). The equilibrium moisture content EM depends on the temperature and humidity _L of the atmosphere. Note that from an operational point of view, as more moisture content is removed from the coal, a higher calorific value is achieved, so the dried coal preferably has as low a moisture content as possible. If, 5 however, the moisture content of the coal discharged from the coal drying process facility 300 is below the equilibrium moisture content EM in the atmosphere, the coal will disadvantageously absorb moisture in the atmosphere. [0060] 10 Therefore, to prevent the dried coal from reabsorbing moisture and ensure the drying efficiency, it is important that the control unit 3 controls the adjustment device 4 to control the temperature GT of the heat gas supplied to the coal drying process facility 300 so that the coal is dried 15 to a moisture content not below the predetermined equilibrium moisture content EM. Note that a moisture content not below the equilibrium moisture content EM is moisture not less than the equilibrium moisture content EM of the coal, and not more than 1.3 times of the equilibrium moisture content thereof. 20 Preferably, it is not less than the equilibrium moisture content EM of the coal, and not more than 1.2 times of the equilibrium moisture content. [0061] Specifically, when the coal to be dried is, for example, 25 sub-bituminous coal of the total moisture content TM of 25 mass% and the equilibrium moisture content EM of 15 mass%, the post-drying moisture content DM is as low as possible, while it should be prevented from being below 15 mass%. For example, it is from 15 mass% to 19.5 mass%, and preferably 30 from 15 mass% to 18 mass%. [0062] Here, if the fuel is coal, for example, the totalmoisture content TM refers to the moisture content contained by the coal before the drying process, i.e., the moisture content 35 contained by the coal sample collected. The total moisture content TM is measured in conformity to JIS M8820 (method of lot-measuring total moisture of various types of coal and cokes). Further, the equilibrium moisture content EM is measured using coal after a drying process as a sample, and according to, for example, JIS A1475 (method of measuring 5 equilibrium water-content ratio of architectural materials). This measurement may provide a curve of equilibrium water-content ratio of the dried coal. [0063] The equilibrium water-content ratio of the coal after 10 a drying process is determined using the curve of equilibrium water-content ratio provided here and information on the temperature and relative humidity of above each atmosphere to which the dried coal is exposed. The determined equilibrium water-content ratio means a percentage of water 15 mass based on total mass after drying.. Therefore, the equilibrium moisture content of the coal after a drying process can be obtained by converting it to the percentage of the water mass based on the total mass before drying by the following formula (1). 20 [0064] [Formula 1] Equilibrium moisture content (mass%) = equilibrium water-content ratio + (100 + equilibrium water-content ratio) x 100 ... (1) 25 [0065] The treatment system 1 according to the first embodiment uses, in the coal drying process facility 300, the exhaust heat energy from the cement manufacture facility 200 to provide the effective use of the heat energy. In other words, 30 the cement manufacture facility 200 may be configured like well-known cement manufacture facilities. [0066] The cement manufacture facility 200 grinds, for example, raw materials such as limestone, clay, silica stone, and iron 35 raw materials in a mill 201. The facility 200 then calcinates the ground raw materials such as limestone, clay, silica stone, 4U and iron raw materials in a calcination device 202 using coal as fuel at a temperature of, for example, about 1450*C. Thus, cement clinkers are obtained. Then, a clinker cooler 203 cools the calcinated cement clinkers. A mixing mill 204 then 5 mixes the cooled cement clinkers with gypsum and other admixtures or the like and grinds the mixture, thus providing powdery cement. [0067] Exhaust gas having heat of about 300'C is discharged from 10 the clinker cooler 203. However, the exhaust heat of the exhaust gas has currently been unused and almost just discharged. The treatment system 1 is configured to use the unused exhaust heat of the exhaust gas as the heat gas in the drying process in the coal drying process facility 300 by 15 little modifying the existing facility. [0068] Specifically, the heat gas discharged from the clinker cooler 203 in the cement manufacture facility 200 is introduced to a heat exchanger 4A as the adjustment device 20 4, where the heat exchange is performed under control of the control unit 3. Then, the heat gas is adjusted to a predetermined temperature GT as described above and then supplied to the coal drying process facility 300. [0069] 25 The control unit 3 acquires from the DB2 information on the moisture amount (the total moisture content TM and the equilibrium moisture content EM) and the temperature of the firing point IT of each type of coal to be dried. According to the information, the control unit 3 determines the 30 temperature GT and post-drying moisture content DM of the heat gas. Further, according to the mass WC (t/h) of the coal to be supplied to the coal drying process facility 300 per unit time, the control unit 3 calculates the heat amount QD (MJ/h) of the coal necessary per unit time and the flow rate VD (m 3 /h) 35 of the heat gas necessary per unit time in the drying process facility 300. Then, the control unit 3 controls the heat L I exchanger 4A to supply the calculated heat amount QD and flow rate VD. [0070] Here, the temperature of the firing point IT is a 5 temperature at which coal ignites. The temperature of the firing point IT is, for example, a temperature measured according to JIS K7193 (method of examination of ignition temperature using a hot-air furnace for plastics). [0071] 10 Note that a temperature slightly below the temperature of the firing point IT is, for example, a temperature below the temperature of the firing point IT by about 80 to 30 0 C, and preferably a temperature below the IT by about 50 to 300C. Specifically, when sub-bituminous coal having a temperature 15 of a firing point IT of 230'C is to be dried, for example, the heat gas temperature GT is set to about 150 to 200'C, preferably about 180 to 200 0 C. [0072] Therefore, the heat exchanger 4A supplies heat gas to 20 the coal drying process facility 300. The heat gas has a temperature GT and a flow rate VD that may eliminate the risk of coal ignition in the coal drying process facility 300 while efficiently drying the coal. As described above, the treatment system 1 is intended to effectively use the unused 25 exhaust heat in the drying process of the low grade coal in the coal drying process facility 300. This may thus provide the effective use of the heat energy and the positive use of the low grade fuel. [0073] 30 [Second Embodiment] FIG. 3 is a block diagram generally illustrating the entire fuel treatment system according to a second embodiment of the present invention. Note that in the following, the portion overlapping the already described portion is provided 35 with the same reference symbol, and its description is omitted. With reference to FIG. 3, a treatment system 1 according to the second embodiment is different from the treatment system 1 according to the first embodiment in that instead of the heat exchanger 4A in the treatment system 1 according to the first embodiment, the water supply heater 104 in the coal 5 thermal power station 100 is used as the adjustment device 4. [0074] Specifically, the heat gas discharged from the clinker cooler 203 in the cement manufacture facility 200 is 10 introduced to the water supply heater 104 as the adjustment device 4. Then, the control unit 3 controls the water supply heater 104, as described above, to adjust the temperature GT and flow rate VD of the heat gas. The adjusted heat gas is then supplied to the coal drying process facility 300. Such 15 a configuration may also provide, like the configuration in the first embodiment, the effective use of the heat energy and the positive use of the low grade fuel. [0075] [Third Embodiment] 20 FIG. 4 is a block diagram generally illustrating the entire fuel treatment system according to a third embodiment of the present invention. With reference to FIG. 4, like the treatment system 1 according to the second embodiment, a treatment system 1 according to the third embodiment comprises, 25 as the adjustment device 4, the water supply heater 104 in the treatment system 1 according to the second embodiment. Unlike the second embodiment, however, the adjustment device 4 in the third embodiment further comprises a distribution device 111 and a mixing device 112. 30 [0076] Specifically, the heat gas from the clinker cooler 203 in the cement manufacture facility 200 is distributed by the distribution device 111 comprising a multi-port valve and a flow path switching valve or the like. Then, some of the heat 35 gas is supplied to the water supply heater 104 and the rest is supplied to a bypass path (not shown) provided in parallel with the water supply heater 104. Then, the heat gas that is reduced in temperature by the water supply heater 104 and the heat gas having passed the bypass path are mixed by the mixing device 112 such as a mixing valve. The mixture is then 5 supplied to the coal drying process facility 300. The distribution device 111 and the mixing device 112 comprise a blanch line such as T- or Y-pipe with a control valve provided thereto. [0077] 10 In this case, the control unit 3 controls the distribution device 111 to distribute the flow rate to the bypass path and the water supply heater 104 such that the mixed heat gas has a safe temperature. Then, the control unit 3 controls the mixing device 112 to mix the high temperature 15 gas and the low temperature gas so that the heat gas to be supplied to the coal drying process facility 300 is controlled to a predetermined temperature GT and a flow rate VD. In such a configuration, both of the coal drying process facility 300 and the water supply heater 104 may use the heat, thus 20 providing the effective use of the heat energy and the positive use of the low grade fuel like the second embodiment. [0078] [Fourth Embodiment] FIG. 5 is a block diagram generally illustrating the 25 entire fuel treatment system according to a fourth embodiment of the present invention. With reference to FIG. 5, like the treatment system according to the first embodiment, a treatment system 1 according to the fourth embodiment uses the heat exchanger 4A as the adjustment device 4. Unlike the 30 treatment system according to the first embodiment, however, the treatment system 1 according to the fourth embodiment further comprises the distribution device 111. [0079] Specifically, the heat gas from the clinker cooler 203 35 in the cement manufacture facility 200 is introduced to the heat exchanger 4A, where the heat exchange is performed under control of the control unit 3 to set the heat gas to a predetermined temperature GT. Further, the distribution device 111 is controlled on the basis of the necessary flow rate VD to the coal drying process facility 300 and the water 5 supply heater 104. Then, the temperature-controlled heat gas is distributed to each of the coal drying process facility 300 and the water supply heater 104. Such a configuration may also provide, like the configuration in the first embodiment, the effective use of the heat energy and the 10 positive use of the low grade fuel. [0080] Note that although not shown, the coal drying process facility 300 may be configured to comprise a paddle agitation-type drier that agitates fuel on a gas distribution 15 plate with paddles while drying the fuel. The paddle agitation-type drier has an interior that is divided into an upper drying chamber and a lower air chamber by a gas distribution plate, for example. Further, the paddle agitation-type drier is configured to comprise a large number 20 of slit openings arranged on the gas distribution plate and a paddle shaft laterally laid in the drying chamber, the paddle shaft being rotatable at variable speed. [0081] The paddle shaft has a plurality of fuel-agitating 25 paddles mounted thereto in the axial direction of the paddle shaft. The paddles are adjacent in the axial direction of the paddle shaft. The paddles are mounted such that the mounting angles of the paddles are shifted in phase to each other as seen in the axial direction. Each paddle is itself 30 tilted relative to the shaft line of the paddle shaft such that the fuel is provided with an agitation force in the shaft line direction. The tilt angle is adjustable. Further, a feeding port and a discharging port for fuel are provided to one end side and the other end side of the paddle shaft of 35 the drying chamber, respectively. The heat gas is introduced to the air chamber, and then the heat gas is sprayed into the drying chamber at a high speed through the slit openings on the gas distribution plate to thereby fluidize the fuel. [0082] [Fifth Embodiment] 5 Further, in the coal thermal power station 100 in the treatment system 1 according to the above embodiment, the boiler 102 may have a combustion furnace configured as follows to effectively treat the exhaust gas from the coal thermal power station 100. FIG. 6 shows a structure of a combustion 10 furnace of a thermal power facility in a fuel treatment system according to a fifth embodiment of the present invention. [0083] A desulfurizing agent injecting device for injecting desulfurizing agent is provided in a combustion furnace 20 15 for combusting fuel. The desulfurizing agent may be supplied alone and directly in an interior of the combustion furnace 20. Further, the desulfurizing agent may be mixed with pulverized coal in advance and then be supplied in the interior of the combustion furnace 20. An injecting inlet for the 20 desulfurizing agent is provided on the combustion furnace 20 at a position that may provide more suitable and efficient capture of SO 3 . A preferable form of the injecting inlet for the desulfurizing agent will be described below. [0084] 25 With reference to FIG. 6, the desulfurizing agent is injected into the combustion furnace 20 through a not-shown desulfurizing agent supply pipe. The desulfurizing agent supply pipe is connected to a desulfurizing agent injecting inlet 14 provided in a wall section 20a of the combustion 30 furnace 20. Preferably, the desulfurizing agent injecting inlet 14 is provided in the upper portion of the combustion furnace 20. Additionally, it is particularly preferred that the desulfurizing agent injecting inlet 14 is formed to enable injection of the desulfurizing agent 15 into a vicinity 35 position of a nose section 21 (which may be referred to as an upper nose section 21) formed upwardly in the combustion furnace 20. Thus, the desulfurization (removal of SO 3 ) in the combustion furnace may be efficiently performed. The supply position of the desulfurizing agent 15 is not limited to the above position. The supply position may be formed to inject, 5 for example, the desulfurizing agent 15 into the combustion furnace 20 as appropriate, even if the nose section 21 is not formed. [0085] The nose is a protruding object provided in a furnace 10 and functioning to divert combustion gas to prevent the combustion gas from flowing through a short path, but cause it to pass through a overheater 20b, thereby securing a retention time of the combustion gas. The nose section 21 redirects the combustion gas flow in the combustion furnace, 15 thus highly mixing the combustion gas. Further, "the vicinity position of the nose section 21" is a portion shown by H (or L + M) in FIG. 6. [0086] Specifically, "the vicinity position of the nose section 20 21" is included in a range of a height direction defined by a base of a triangle of the nose section 21. Also, "the vicinity position of the nose section 21" is a space in the combustion furnace 20 included in the range of the height direction, but a space where the overheater 20b is not present. 25 The overheater 20b extends from an upper side of the nose section 21 to the space of the nose section 21. Then, the desulfurizing agent 15 is supplied to that space. The number of the desulfurizing agent injecting inlets 14 is 1, or 2 or more. Among, these numbers in view of appropriately 30 dispersing the desulfurizing agent 15 in the combustion furnace 20, 2 or more, particularly 4 to 6, is preferable. If the position of the desulfurizing agent injecting inlet 14 is in the range of "H" of the nose section, a plurality of the desulfurizing agent injecting inlets 14 may be provided 35 in the height direction. [0087] 4 / Preferably, the desulfurizing agent 15 comprises calcium compounds such as calcium hydroxide, calcium oxide, and calcium carbonate. More preferably, the desulfurizing agent is cement plant dust comprising calcium carbonate 5 (CaCO 3 ) as a main component. The cement plant dust is recovered from, for example, exhaust gas of a process for manufacturing cement raw material. The dust has a mass based average particle size of about 2pm, and is available at a very inexpensive price and in large quantities. 10 [0088] The desulfurizing agent 15 is injected into the vicinity position of the upper nose portion 21 in the combustion furnace 20. The injected desulfurizing agent 15 may thus capture SO 3 generated by combustion of fuel more suitably and efficiently. 15 The cement plant dust comprises dust recovered from the mill 201 in the cement manufacture facility 200 and dust recovered from exhaust gas from the calcination device 202. [0089] Specifically, for example, when calcium carbonate is 20 used as the desulfurizing agent 15, a decarboxylation reaction causes the calcium carbonate to become calcium oxide (CaCO 3 --CaO) , and a desulfurizing reaction causes this calcium oxide CaO to react with sulfur dioxide SO 2 to become calcium sulfate (CaO+SO 2 +0.50 2 -CaSO 4 ) . Further, the calcium oxide 25 CaO after the decarboxylation reaction captures SO 3 . The inventors have discovered that the desulfurizing reaction may be most activated by injecting the desulfurizing agent 15 in the vicinity position of the upper nose section 21 in the combustion furnace 20. 30 [0090] Regarding amount of supply of desulfurizing agent with respect to fuel, a molar ratio (Ca/S) of calcium (Ca) to the sulfur content (S) in the desulfurizing agent provided in the fuel is preferably between 0.5 and 3, more preferably between 35 1 and 2.5. If the molar ratio exceeds 3, the amount of dust increases. Specifically, the inventors have experimentally demonstrated that the desulfurizing agent 15 injected into a position lower than the upper nose section 21 in the combustion furnace 20 provides a high internal temperature of the furnace, which causes CaO to be used in modification 5 of coal ash (cement mineralization reaction) or the like and causes a reverse reaction of the desulfurization or the like. The inventors have also demonstrated that the desulfurizing agent 15 injected into a position higher than the upper nose section 21 in the combustion furnace 20 provides a low internal 10 temperature of the furnace, which causes an insufficient decarboxylation reaction, which may cause insufficient capture of S03. [0091] In contrast, the desulfurizing agent 15 injected into 15 a vicinity position of the upper nose section 21 as described above may ensure a moderate contact time between CaO and S03. Further, the highly disturbed gas flow effectively distributes CaO in gas layers in the combustion furnace 20 and CaO captures SO 3 , thus activating the desulfurization 20 reaction. [0092] This may prevent the phenomenon in which the concentration of SO 3 is locally increased in the combustion furnace 20, thus causing condensation, and the condensation 25 generates sulfuric acid, which corrodes the portion to which the sulfuric acid adheres. Note that in injecting the desulfurizing agent 15, the preferable internal temperature of the combustion furnace 20 is, for example, in the range of 1050 0 C to 1150 0 C. The above configuration may effectively 30 remove SO 2 and SO 3 in the combustion furnace 20, thus effectively treating the exhaust gas in the coal thermal power station 100. [0093] [Sixth Embodiment] 35 FIG. 8 shows a structure of a combustion furnace of a thermal power facility in a fuel treatment system according to a sixth embodiment of the present invention. FIG. 9 is a block diagram generally illustrating the entire fuel treatment system according to the sixth embodiment of the present invention. With reference to FIG. 8 and FIG. 9, a 5 fuel treatment system 1 according to this embodiment is applicable to a coal thermal power station 100. [0094] The coal thermal power station 100 comprises, by way of example, the grinding device 101 for grinding coal used as 10 fuel, the boiler 102 for combusting the coal to evaporate externally supplied water W4 to provide steam, the electric generator 103 comprising a not-shown steam turbine, and the water supply heater 104 for heating water W3 supplied to the boiler 102. 15 [0095] The boiler 102 comprises, for example, a supply port for supplying fuel, desulfurizing agent, and oxygen-containing gas, and a discharge port for discharging exhaust gas after combusting the fuel using the oxygen-containing gas. The 20 fuel is carbonaceous and is combusted with oxygen. The oxygen-containing gas is gas that contains oxygen. Specific examples of the oxygen-containing gas comprise air, oxygen, or the like. The supply port for supplying the fuel, the desulfurizing agent, and the oxygen-containing gas may be 25 provided as three separate supply ports. Further, a portion of the oxygen-containing gas and the fuel may be supplied through the same supply port of the boiler 102. [0096] The treatment system 1 comprises a desulfurizing agent 30 supply device 10 for supplying the desulfurizing agent in the combustion furnace of the boiler 102, the denitrification device 105, the heat recovery device 106, an indirect heat exchange mechanism 110, and the electric dust collector 107. Note that the denitrification device 105 is an arbitrary 35 configuration, and may be omitted in the configuration of the treatment system 1. Further, the electric dust collector 107 may be replaced with a collection device such as a bag filter. [0097] First, the desulfurization process in the combustion furnace 20 of the boiler 102 (the internal furnace 5 desulfurization) will be described. With reference to FIG. 8, in the treatment system 1, the desulfurizing agent supply device 10 comprises, for example, a storage tank 11 for storing desulfurizing agent 15 transferred by a truck 90 or the like, and a constant rate discharge mechanism 12 and a blower 13 10 for supplying the desulfurizing agent 15 stored in the storage tank 11 to the combustion furnace 20 as appropriate. [0098] After being transferred from the storage tank 11 by the constant rate discharge mechanism 12 and the blower 13, the 15 desulfurizing agent 15 is injected and supplied into the combustion furnace 20 through, for example, a not-shown desulfurizing agent supply pipe. [0099] Note that in injecting the above desulfurizing agent 15 20 in the vicinity position of the upper nose section 21, the preferable internal temperature of the combustion furnace 20 is in the range of about 1050 0 C to 1150 0 C. Then, after having its SO 2 and S03 removed in the combustion furnace 20 as described above, the exhaust gas is discharged from the 25 combustion furnace 20 through a flue 22, and then denitrified by, for example, the above denitrification device 105. Further, the exhaust gas is reduced in temperature by the heat recovery device 106 (the temperature is decreased), and then supplied to a gas-water heat exchanger 121 provided as a first 30 heat-exchange device in the indirect heat exchange mechanism 110. [0100] In the gas-water heat exchanger 121, circulating heat medium Wl circulating through a circulation conduit 50 35 followed by a conduit 51 exchanges the heat of the exhaust gas, and then the heat of the circulating heat medium W1 is provided to water W2 by a heat exchanger 122 provided as a second heat-exchange device. [0101] Note that conventionally, exhaust gas discharged from 5 the combustion furnace 20 contains SO 3 at about 1% of SO 2 , and a sulfuric acid dew point is about 120cC to 130 0 C. Thus, the heat recovery from the exhaust gas is limited up to a temperature of about 150'C of the exhaust gas. In contrast, in the treatment system 1 according to the sixth embodiment, 10 the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 in the combustion furnace 20 removes SO 3 in exhaust gas in advance. The sulfuric acid dew point may thus be reduced drastically. The inventors have demonstrated that specifically, the exhaust gas may thus be 15 cooled to a temperature of, for example, about 100'C by the gas-water heat exchanger 121, thereby increasing the heat recovery amount and thus significantly improving the energy efficiency. [0102] 20 The recovered heat energy is heat-exchanged by the gas-water heat exchanger 121 with the circulating heat medium Wl to increase the W1 temperature to about 75'C. The circulating heat medium W1 is then sent through the circulation conduit 50 to the heat exchanger 122 where the 25 heat medium W1 is used to preheat the water W2. The energy efficiency of the boiler 102 may thus be improved. If, for example, in a power generation boiler at the level of the main steam amount of 150 t/h, the heat is recovered from the exhaust gas so that the gas temperature is reduced from 150'C to 100'C, 30 the heat efficiency may be improved by 2 to 3%. Further, the crude oil reduction is 1970 Kl/year, and the CO 2 reduction is 6800 t/h. Note that the surface of the line 51 in the gas-water heat exchanger 121 is in contact with the exhaust gas, and thus if the surface temperature is below the dew-point 35 of the exhaust gas, condensation will occur. [0103] In this case, it is concerned that coal ash adheres to the inside of the gas-water heat exchanger 121 including the conduit 51 or the like, thus blocking the gas flow channel. Thus, in the indirect heat exchange mechanism 110, in order 5 to ensure that the surface temperature of the conduit 51 is not below the dew-point of the exhaust gas, it is preferred to appropriately manage the temperature of the circulating heat medium W1 circulating through the circulation conduit 50, appropriately set the heat exchange by the heat exchanger 10 122, and appropriately manage the surface temperature of the conduit 51. Therefore, in the heat exchanger 122, it is preferred to exchange heat between the circulating heat medium W1 circulating through the circulation conduit 50 and the water W2 such that the temperature of the heat medium W1 is 15 not too reduced in the heat exchanger 122. [01041 For example, in a coal power generation boiler at the level of the main steam amount of 150 t/h, a bypass line (not shown) is provided for adjusting the amount of heat medium 20 passing through the heat exchanger 122 such that the temperature of the circulating heat medium W1 returning to the gas-water heat exchanger 121 is a temperature (for example 55 0 C) higher than the dew-point of the exhaust gas (for example, 48-C). 25 [0105] Preferably, the bypass amount is adjusted in the range of 0 to 80% of the circulating heat medium amount. Further, the bypass amount depends on the temperature of the water W2 externally supplied. If, for example, the water W2 is 30 supplied at 48'C, the bypass ratio of the circulating heat medium W1 is 0% (the total amount passes through the heat exchanger 122), and if the water W2 is at 25 0 C, the bypass ratio of the circulating heat medium W1 is about 60%. [0106] 35 In this way, each device such as the gas-water heat exchanger 121 does not need to be made of expensive corrosion resistant materials. For example, the material of portions in contact with the exhaust gas, such as the conduit 51, may be made of an inexpensive carbon steel (carbon steel) material, or the like. Further, the boiler may be operated stably 5 without the gas flow channel blocked. Note that it has been found that the reduction of the temperature of the exhaust gas from the combustion furnace 20 by the indirect heat exchange mechanism 110 as described above largely affects the maintenance and improvement of the collection performance of 10 the electric dust collector 107 provided at the next stage. [0107] Specifically, in the treatment system 1 according to the sixth embodiment, the removal of S03 in the exhaust gas by the desulfurizing agent 15 in the combustion furnace 20 gives 15 a certain solution to problems such as corrosion. However, excess removal of SO 3 in the exhaust gas may significantly reduce the collection performance of the electric dust collector 107. [0108] 20 It is generally believed that the collection performance of the electric dust collector 107 depends on the elements of (A) exhaust gas temperature, (B) exhaust gas speed (flow rate) , and (C) SO 3 concentration, and that the higher (C) the

SO

3 concentration is, the higher the collection performance 25 is. The treatment system 1 according to the sixth embodiment removes S03 using the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 in the combustion furnace 20. Therefore, when exhaust gas having a low concentration of SO 3 is supplied to the electric dust 30 collector 107, the expected collection effect may not be obtained. [0109] Therefore, the heat recovery device 106 and the indirect heat exchange mechanism 110 are provided between the 35 combustion furnace 20 and the electric dust collector 107 to reduce the temperature of exhaust gas discharged from the combustion furnace 20. This may reduce the volume of the exhaust gas and the flow rate of the exhaust gas. Thus, the concentration of SO 3 in the exhaust gas may not be enough to affect the collection performance of the electric dust 5 collector 107, thereby maintaining and improving the collection performance. Note that the exhaust gas discharged from the electric dust collector 107 is transferred by a blower 48 and discharged through a stack 49 into the atmosphere. [0110] 10 Further, with reference to FIG. 9, it is preferable that coal used in the coal thermal power station 100 is dried by, for example, the coal drying process facility 300. Further, according to the sixth embodiment, the coal thermal power station 100 comprises the cement manufacture facility 200 15 provided along with it. The cement manufacture facility 200 discharges heat gas from the clinker cooler 203 described below. The heat gas is used in the water supply heater 104 to heat the water W3 supplied to the boiler 102. This provides a configuration that may totally effectively use the heat 20 energy of the exhaust gas. [0111] In addition to being discharged from the cement manufacture facility 200, the heat gas may be discharged from, for example, a hot air production furnace. The heat gas may 25 also be gases such as heating furnace exhaust gas and boiler exhaust gas. Among others, in terms of the effective use of the heat energy, it is preferable to use the boiler exhaust gas and the clinker cooler exhaust gas. Here, coal or low grade fuel may not need to be dried depending on the contained 30 moisture amount. If so, then a configuration may be provided that the coal drying process facility 300 is omitted. [0112] In the coal thermal power station 100, the dried coal supplied from, for example, the coal drying process facility 35 300 is ground to a predetermined size by the grinding device 101, and the ground coal is combusted in the combustion furnace 20 of the boiler 102 (see FIG. 8). [0113] Then, the heat energy evaporates the water W4 supplied from the water supply heater 104 into steam. The steam is 5 used in the electric generator 103 for power generation and power supply. Note that the water supply heater 104 may be configured to receive a feedback of the excess steam from the electric generator 103 and use the steam to heat the water W3 supplied to the boiler 102. Thus, the heat efficiency of 10 the electric generator 103 may be improved. [0114] The water supply heater 104 may also be configured to use the heat gas from the cement manufacture facility 200 to heat the water W3. 15 [0115] Meanwhile, the exhaust gas generated in the boiler 102 has its sulfur oxide (SOx) removed by the desulfurizing agent supplied in the combustion furnace 20 from the desulfurizing agent supply device 10. Additionally, the denitrification 20 device 105, for example, removes the nitrogen oxide (NOx). The desulfurized and denitrified exhaust gas further has its temperature reduced by the heat recovery device 106. [0116] The heat recovered by the heat recovery device 106 may 25 be used to raise, for example, the temperature of the combustion air pumped into the boiler 102. The heat recovered by the heat recovery device 106 may also be used to raise the temperature of drying air for drying the coal in the grinding device 101. After passing through the heat recovery device 30 106, the exhaust gas is supplied to the gas-water heat exchanger 121 in the indirect heat exchange mechanism 110. [0117] In the gas-water heat exchanger 121, the exhaust gas supplied from the heat recovery device 106 and the circulating 35 heat medium W1 circulating through the circulation conduit 50 are indirectly contacted via the conduit 51 of the ~J circulation conduit 50 to perform the heat exchange. Thus, the gas-water heat exchanger 121 is configured to cool the exhaust gas supplied from the heat recovery device 106. The heat medium in the present invention is a medium for 5 transferring heat to other parts. Note that the circulating heat medium W1 may comprise water, silicone oil, mineral oil, or the like. Among others, in view of the heat transfer, water is preferable. The indirect heat exchange mechanism 110 comprises the gas-water heat exchanger 121 as well as the heat 10 exchanger 122, which are connected via the circulation conduit 50. [0118] The circulating heat medium W1 circulating through the circulation conduit 50 is heated by the gas-water heat 15 exchanger 121, and introduced in the heat exchanger 122. The heat exchanger 122 brings the externally supplied water (preferably deionized water) W2 to be supplied to the boiler 102 into contact with the circulation conduit 50, thus providing the heat energy of the circulating heat medium W1 20 to the water W2 to heat the water W2. The heated water W3 is supplied to the water supply heater 104. [0119] A bypass line (not shown) is provided for adjusting the amount of heat medium passing through the heat exchanger 122 25 such that the temperature of the circulating heat medium W1 returning to the gas-water heat exchanger 121 is a temperature (for example 55 0 C) higher than the dew-point of the exhaust gas (for example, 48 0 C). Preferably, the bypass amount is adjusted in the range of 0 to 80% of the circulating heat medium 30 amount. Further, the bypass amount depends on the temperature of the water W2 externally supplied. [0120] If, for example, the water W2 is supplied at 48 0 C, the bypass ratio of the circulating heat medium W1 is 0% (the total 35 amount passes through the heat exchanger 122), and if the water W2 is at 25'C, the bypass ratio of the circulating heat medium J / Wl is about 60%. Note that after passing through the gas-water heat exchanger 121, the exhaust gas is supplied to the electric dust collector 107. [0121] 5 After passing through the electric dust collector 107, the exhaust gas is discharged into the atmosphere as exhaust gas. By the above process, the coal thermal power station 100 generates power. [0122] 10 Note that the coal thermal power station 100 of the treatment system 1 according to the sixth embodiment may be configured to use, in heating the water W3 by the water supply heater 104, the heat energy of the heat gas supplied from the cement manufacture facility 200 provided along with the power 15 station 100, thus providing the effective use of the heat energy. [0123] The cement manufacture facility 200 may be configured like well-known cement manufacture facilities 200. The 20 clinker cooler 203 discharges heat gas having heat of, for example, about 300'C. However, the heat energy of the heat gas has currently been unused and almost just discharged. The treatment system 1 according to the sixth embodiment is configured to be able to use the heat gas in the water supply 25 heating process in the coal thermal power station 100 by little modifying the existing facility. [0124] Specifically, the heat gas discharged from the clinker cooler 203 in the cement manufacture facility 200 is 30 introduced in the water supply heater 104 to perform the heat exchange. Then, the water W3 heated by the heat exchanger 122 of the indirect heat exchange mechanism 110 is further heated and supplied to the boiler 102 as the water W4. Thus, the treatment system 1 may provide the effective use of the 35 heat energy. Note that the exhaust gas discharged from the water supply heater 104 may further be used in, for example, the drying process in the coal drying process facility 300. [0125] [Seventh Embodiment] FIG. 10 is a block diagram of the entire flow of a method 5 for utilizing of exhaust gas according to a seventh embodiment of the present invention. FIG. 11 shows a detailed configuration of FIG. 10. With reference to FIG. 10 and FIG. 11, the method for utilizing of exhaust gas according to the seventh embodiment is applied to the drying process facility 10 300 as a drying means mainly for drying coal provided as the low grade fuel and the coal thermal power station 100 using the dried coal supplied from the drying process facility 300 for the combustion. [0126] 15 The coal thermal power station 100 comprises, by way of example, the grinding device 101, the boiler 102, the electric generator 103, and the water supply heater 104 for heating deionized water supplied to the boiler 102. The coal thermal power station 100 also comprises the desulfurizing agent 20 supply device 10, the distribution device 111 for distributing exhaust gas from the combustion furnace 20, the denitrification device 105, an exhaust gas temperature reduction means 30, the electric dust collector 107, and the mixing facility 113. 25 [0127] Note that the denitrification device 105 and the mixing facility 113 are arbitrary configurations, and may be omitted in the configuration of the coal thermal power station 100. The coal used as fuel to be dried by the drying process facility 30 300 is any coal that comprises, for example, moisture and sulfur component and needs to be dried before combustion. [0128] Meanwhile, the exhaust gas generated in the combustion furnace 20 of the boiler 102 is discharged from the combustion 35 furnace 20 at a temperature of, for example, about 3000C to 4000C after SO 3 in the combustion gas is removed in the combustion furnace 20 (the internal furnace desulfurization) by the desulfurizing agent 15 supplied in the combustion furnace 20 from the desulfurizing agent supply device 10. [0129] 5 The heat of the discharged exhaust gas is used as a heat source for drying the coal. There are various embodiments of using the heat of the exhaust gas. FIG. 10 shows an embodiment where the desulfurized exhaust gas is supplied to the drying process facility 300 through an exhaust gas supply 10 path, the exhaust gas supply path connecting the combustion furnace used as the combustion means and the drying process facility used as the drying means. It is an embodiment where the heat of the exhaust gas is used as the heat source for drying the coal. The exhaust gas supply path supplies the 15 desulfurized exhaust gas to the drying process facility 300. The drying process facility 300 uses the heat of the exhaust gas to dry the coal. Thus, a configuration is provided that may provide the effective use of the heat energy of the exhaust gas. 20 [0130] Preferably, the discharged exhaust gas is cooled as necessary, and then used to dry the coal in the drying process facility 300. The discharged exhaust gas may also be introduced in and distributed by the distribution device 111 25 having, for example, a distribution line and a control valve or the like. Some of the exhaust gas may thus be used to dry the coal in the drying process facility 300. [0131] Further, the rest of the exhaust gas distributed by the 30 distribution device 111 is introduced in, for example, the denitrification device 105 in the subsequent stage, where nitrogen oxide (NOx) is removed. The desulfurized and denitrified exhaust gas is further introduced in an exhaust gas temperature reduction facility 30 disposed in the 35 subsequent stage of the denitrification device 105. The temperature of the exhaust gas is thus reduced.

14 U [0132] The heat recovered by the exhaust gas temperature reduction facility 30 may be used to, for example, raise the temperature of the combustion air (oxygen-containing gas) 5 pumped into the boiler 102. The heat recovered by the exhaust gas temperature reduction facility 30 may also be used to, for example, raise the temperature of the drying air for drying the coal in the grinding device 101. After passing through the exhaust gas temperature reduction facility 30 and having 10 its temperature reduced, the exhaust gas is supplied to the electric dust collector 107 provided as the dust collection means. [0133] The electric dust collector 107 collects dust (ash 15 content) floating in the exhaust gas. After having its dust (ash content) collected and removed, and passing through the electric dust collector 107, the exhaust gas is discharged into the atmosphere as exhaust gas. Note that the dust collected by the electric dust collector 107 is supplied to, 20 for example, the mixing facility 113. The mixing facility 113 mixes separately transferred dust and a hydrous organic waste material such as sludge, a residue, or livestock excreta. [0134] 25 As described above, dust (ash content) contains a large amount of calcium oxide (CaO). As dust acts as a desiccant, dust may be mixed with a hydrous organic waste material to dry the hydrous organic waste material without using a separate desiccant or a drying process. By the above process, 30 the coal thermal power station 100 generates power. [0135] Note that after having its SO 2 and SO 3 removed in the combustion furnace 20, the exhaust gas is discharged from the combustion furnace 20 through the flue 22. Some of the 35 discharged exhaust gas is supplied to the drying process facility 300 via the distribution device 111 and the rest is supplied to the exhaust gas temperature reduction facility 30. [0136] The exhaust gas temperature reduction facility 30 5 comprises, for example, a gas air heater (GAH) 31 and the gas-water heat exchanger 121 or a water spray device 33. Here, the temperature of the exhaust gas may be reduced in three ways: (1) by improvement of the ability (performance) of the gas air heater, (2) by indirect cooling, and (3) by direct 10 cooling. [0137] However, for (3) direct cooling (i.e., for example, cooling by spraying water in the exhaust gas), dust contained in the exhaust gas may adhere to the inside of the exhaust 15 gas temperature reduction facility 30, thus providing clogging or the like. Therefore, in the seventh embodiment, although (3) direct cooling may be used, (2) indirect cooling may preferably be used. [0138] 20 Specifically, in the exhaust gas temperature reduction facility 30, the circulating heat medium (for example, water) of the gas-water heat exchanger 121 disposed downstream of the gas air heater 31 exchanges heat with the exhaust gas, and the exchanged heat is used to preheat the water supply 25 to the combustion furnace 20. [0139] In the method for utilizing of exhaust gas according to the seventh embodiment, the desulfurizing agent 15 injected into the combustion furnace 20 of the boiler 102, preferably 30 the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 in the combustion furnace 20 removes SO 3 in exhaust gas in advance. This may drastically reduce the sulfuric acid dew point. [0140] 35 Thus, specifically, the exhaust gas temperature reduction facility 30 may cool the exhaust gas to a temperature of, for example, about 100"C. The inventors have demonstrated that the heat recovery amount may thus be increased, thereby significantly improving the energy efficiency. Further, associated with this, each device or 5 the like provided in the exhaust gas temperature reduction facility 30 needs not to be made of expensive corrosion resistant materials. [0141] For example, the material of a portion in contact with 10 the exhaust gas in the gas-water heat exchanger 121 of the exhaust gas temperature reduction facility 30 may be an inexpensive carbon steel (carbon steel) material. In the coal thermal power station 100 according to the seventh embodiment, the desulfurizing agent 15 injected into the 15 combustion furnace 20 of the boiler 102, preferably the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 removes S03, as described above. In addition, the exhaust gas temperature reduction facility 30 is provided between the combustion furnace 20 and the 20 electric dust collector 40. [0142] The exhaust gas temperature reduction facility 30 may reduce the temperature of the exhaust gas discharged from the combustion furnace 20 and distributed by the distribution 25 device 111. The concentration of SO 3 in the exhaust gas may thus not be enough to affect the collection performance of the electric dust collector 107, thereby maintaining and improving the collection performance. Note that the dust collected by the electric dust collector 107 from the exhaust 30 gas is supplied to the mixing facility 113, where the dust is used as a desiccant for the hydrous organic waste material separately transferred to the mixing facility 113. [0143] The coal is dried by the drying process facility in 35 advance before it is combusted in the combustion furnace. In the drying process facility 300, the exhaust gas is used as the drying heat source. Note that the temperature of the exhaust gas is preferably set to a temperature that is low enough to suppress the ignition of the coal in the drying process facility 300 and is as high as possible. As described 5 above, the drying process facility 300 dries so-called low grade coal such as sub-bituminous coal, brown coal, or ignite such that the dried coal has a predetermined moisture. [0144] Note that the method for utilizing of exhaust gas 10 according to the seventh embodiment may be configured to use the heat energy of the exhaust gas from the combustion furnace 20 of the boiler 102 as the drying air supplied to the drying process facility 300 for drying coal to be supplied to the coal thermal power station 100, thus providing the effective 15 use of the heat energy. Into the air chamber of the paddle agitation-type drier of the drying process facility 300, the exhaust gas as well as other heat gases, drying air, or the like may be introduced for drying. [0145] 20 As described above, according to the method for utilizing of exhaust gas according to the seventh embodiment, the exhaust heat from the coal thermal power station 100 may be effectively used and SO 3 in the exhaust gas may be removed, and thus the durability of the facility may be improved and 25 sulfur (S) content in the system may be reduced. This may provide the effective use of the heat energy and an established technology to positively use the low grade fuel or the like. [0146] [Eighth Embodiment] 30 FIG. 12 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to an eighth embodiment of the present invention. FIG. 13 shows the detailed configuration of FIG. 12. With reference to FIG. 12 and FIG. 13, the method for utilizing of exhaust gas according to the 35 eighth embodiment is different from the method according to the seventh embodiment in that the desulfurized exhaust gas 1414 to be used as the drying heat source in the drying process facility 300 is exhaust gas that passes through the exhaust gas temperature reduction facility 30 and the electric dust collector 107 by which its temperature is reduced and its dust 5 (ash content) is removed and that is further distributed by the distribution device 111 installed in the subsequent stage. [0147] Specifically, the exhaust gas from the boiler 102 is reduced in temperature by the exhaust gas temperature 10 reduction facility 30, and then supplied to the electric dust collector 107 where dust in the exhaust gas is removed. Then, some of the exhaust gas from the electric dust collector 107 is distributed by the distribution device 111 and supplied to the drying process facility 300. The rest of the exhaust 15 gas is discharged into the atmosphere. Preferably, the exhaust gas with its dust removed is used as the heat source for drying coal, thus preventing dust adhesion in the drying process facility or the like. This may also provide, like the seventh embodiment, the effective use of the heat energy 20 and an established technology to positively use the low grade fuel. [0148] [Ninth Embodiment] FIG. 14 is a block diagram of the entire flow of a method 25 for utilizing of exhaust gas according to a ninth embodiment of the present invention. FIG. 15 shows the detailed configuration of FIG. 14. With reference to FIG. 14 and FIG. 15, the method for utilizing of exhaust gas according to the ninth embodiment is different from the method according to 30 the seventh embodiment in that the heat exchange is mainly performed between the desulfurized exhaust gas and the heat medium, and the heat medium heated by the heat of the exhaust gas is used as the drying heat source in the drying process facility 300. FIG. 14 shows an embodiment where the heat 35 exchange is performed between the desulfurized exhaust gas and the heat medium, and the heat medium heated by the exhaust gas is supplied to the drying process facility and used as the heat source for drying the coal. [0149] Specifically, the desulfurized exhaust gas is 5 introduced, after passing through the gas air heater 31 and having its temperature reduced, into the gas-water heat exchanger 121. Between the gas-water heat exchanger 121 and the drying process facility 300, the circulation conduit 50 is provided, and circulating heat medium W1 circulates through 10 the circulation conduit 50. In the gas-water heat exchanger 121, the circulating heat medium W1 circulating through the circulation conduit 50 followed by the conduit 51 exchanges the heat of the exhaust gas. [0150] 15 The circulating heat medium W1 is heated by the heat of the exhaust gas in the gas-water heat exchanger 121, and after being raised to a predetermined temperature, the heat medium W1 is supplied to the drying process facility-300 through the circulation conduit 50. In the drying process facility 300, 20 instead of the drying heat source (for example, air) or along with the drying air, the heat of the circulating heat medium W1, which heat is recovered from the exhaust gas, is used as the drying heat source to dry the coal as described above. [0151] 25 Note that in the ninth embodiment, the coal thermal power station 100 may be configured to comprise, for example, the cement manufacture facility 200 provided along with it. The method for utilizing of exhaust gas according to the ninth embodiment is configured to be able to use the heat gas in 30 the water supply heating process in the coal thermal power station 100 by little modifying the existing facility. [0152] Specifically, for example, the heat gas discharged from the clinker cooler 203 in the cement manufacture facility 200 35 is introduced in the water supply heater 104 for the heat exchange, and thus the water introduced to the water supply heater 104 is heated and supplied to the boiler 102. Therefore, the ninth embodiment may provide the effective use of the heat energy. [0153] 5 Note that the exhaust gas discharged from the water supply heater 104 may further be used in, for example, the drying process in the drying process facility 300. The use of the exhaust gas according to the ninth embodiment may also provide, like the seventh embodiment, the effective use of 10 the heat energy and an established technology to positively use the low grade fuel. In the ninth embodiment, the heat exchange is performed between the desulfurized exhaust gas and the heat medium, and the heat-exchanged exhaust gas is discharged into the atmosphere via an electric dust collector 15 107. After the desulfurized exhaust gas is supplied in the dust collection means in advance and the ash content contained in the exhaust gas is removed, the heat exchange may be performed between the exhaust gas and the heat medium. [0154] 20 [Tenth Embodiment] FIG. 16 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a tenth embodiment of the present invention. FIG. 17 shows the detailed configuration of FIG. 16. With reference to FIG. 16 and FIG. 25 17, the method for utilizing of exhaust gas according to the tenth embodiment is different from the method according to the ninth embodiment in that the heat exchange is mainly performed between the desulfurized exhaust gas and the heat medium, and some of the heat medium is used to heat the water 30 to be supplied to the boiler 102. [0155] Specifically, the desulfurized exhaust gas is supplied, after passing through the gas air heater 31 and having its temperature reduced, in the indirect heat exchange mechanism 35 110 having the gas-water heat exchanger 121 and the heat exchanger 122. In the indirect heat exchange mechanism 110, the gas-water heat exchanger 121 brings the circulating heat medium W1 circulating through the primary circulation conduit 50A into indirect contact with exhaust gas to exchange the heat of the exhaust gas, and supplies the heat to the drying 5 process facility 300. Further, a circulating heat medium Wla, which is a portion of the circulating heat medium Wi, is supplied via a secondary circulation conduit 50B to the heat exchanger 122 where the heat is given to the water W2. [0156] 10 The heat exchanger 122 brings the externally supplied water (preferably deionized water) W2 to be supplied to the boiler 102 into contact with the secondary circulation conduit 50B, thus providing the heat energy of the circulating heat medium Wla to the water W2 to heat the water W2. Note that 15 the heated water W3 is supplied to the water supply heater 104. [0157] The primary circulation conduit 50A and the secondary circulation conduit 50B are connected in the gas-water heat 20 exchanger 121 by a not-shown valve device or the like such that each path may be branched. Therefore, under a predetermined control, the circulating heat media W1 and Wla may circulate through the primary circulation conduit 50A and the secondary circulation conduit 50B, respectively. 25 [0158] The heat energy recovered by the indirect heat exchange mechanism 110 is used as follows for example: the circulating heat medium Wl is heat exchanged in the gas-water heat exchanger 121 and raised to a temperature of about 75'C, and 30 then the heat medium Wla, which is a portion of the medium W1, is passed through the secondary circulation conduit 50B and used to preheat the water W2 in the heat exchanger 122. Thus, the energy efficiency of the boiler 102 may be improved. Note that the dew-point is the temperature at which the 35 moisture in the gas begins to condense. [0159] 140 In this case, it is concerned that coal ash adheres to the inside of the gas-water heat exchanger 121 including a conduit or the like, thus blocking the gas flow channel. Thus, in the indirect heat exchange mechanism 110, in order to ensure 5 that the surface temperature of the conduit is not below the dew-point of the exhaust gas, it is preferred to appropriately manage the temperature of the circulating heat medium Wl circulating through the primary circulation conduit 50A, appropriately set the heat exchange by the heat exchanger 122, 10 and appropriately manage the surface temperature of the conduit. [0160] Therefore, in the indirect heat exchange mechanism 110, in order that the circulating heat media Wl and Wla circulating 15 through the primary circulation conduit 50A and the secondary circulation conduit SOB are not too reduced in temperature in the drying process facility 300 or the heat exchanger 122, it is preferred to dry the coal or to heat exchange the media W1 and Wla with the water W2. Note that the water W3 raised 20 in temperature by the heat exchanger 122 as described above is introduced, for example, to the water supply heater 104 and heated thereby, and then supplied to the boiler 102 as water W4. Such a use of the exhaust gas may also provide, like the ninth embodiment, the effective use of the heat energy 25 and an established technology to positively use the low grade fuel. [0161] In the tenth embodiment, the heat exchange is performed between the desulfurized exhaust gas and the heat medium, and 30 the heat-exchanged exhaust gas is discharged into the atmosphere via the electric dust collector 107. After the desulfurized exhaust gas is supplied in the dust collection means in advance and the ash content contained in the exhaust gas is removed, the heat exchange may be performed between 35 the exhaust gas and the heat medium. [0162] [Eleventh Embodiment] FIG. 18 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to an eleventh embodiment of the present invention. With reference to FIG. 5 18, the method for utilizing of exhaust gas according to the eleventh embodiment is applied to the drying process facility 300 mainly for drying coal provided as the low grade fuel and the coal thermal power station 100 using the dried coal supplied from the drying process facility 300 for the 10 combustion. [0163] The coal thermal power station 100 comprises the denitrification device 105, the heat recovery device 106, the mixing device 112, the electric dust collector 107, and the 15 desulfurization device 108. Note that in the eleventh embodiment, the coal thermal power station 100 is configured to comprise the cement manufacture facility 200 provided along with it. Heat gas is mixed with exhaust gas from the boiler 102 by the mixing device 112, and then used to dry coal in 20 the drying process facility 300. This provides a configuration that may totally perform the effective use of the heat energy of the exhaust gas. [0164] Meanwhile, the exhaust gas generated in the boiler 102 25 is discharged at a temperature of, for example, about 500'C to 10000C, and then has its nitrogen oxide (NOx) removed by the denitrification device 105 in the subsequent stage. Then, the exhaust gas is heat exchanged with the air or the like and thus reduced in temperature by the heat recovery device 30 106 such as the gas air heater (GAH) provided as the exhaust gas temperature reduction means. [0165] In the eleventh embodiment, the exhaust gas after passing through the heat recovery device 106 is supplied to 35 the mixing device 112. The exhaust gas has, for example a temperature of about 900C and an oxygen concentration of about DU 5 vol%. The mixing device 112 is also provided with heat gas discharged from the clinker cooler 203 in the cement manufacture facility 200. [01661 5 The heat gas has, for example, a temperature of about 300'C and an oxygen concentration of about 21 vol%. The mixing device 112 has a not-shown configuration comprising a control valve and a control device for controlling the gas mixing, a gas line, or the like. Then, the mixing device 112 mixes 10 the exhaust gas and heat gas to generate mixed gas having a temperature of 150'C or more, preferably 2000C or more, and an oxygen concentration of 10 vol% or less. The mixing device 112 then supplies the generated mixed gas to the drying process facility 300. 15 [0167] Specifically, the mixing device 112 mixes, for example, a 68.7 amount (%) exhaust gas having a temperature of 900C and an oxygen concentration of 5 vol% and a 31.3 amount (%) heat gas having a temperature of 3000C and an oxygen 20 concentration of 21 vol%. Thus, mixed gas having a temperature 156'C and an oxygen concentration of 10 vol% is generated. Note that in the drying process facility 300, drying air having a too high temperature (i.e., drying air having a temperature higher than the temperature of the firing 25 point of coal) or drying air having a too high oxygen concentration both increases the possibility of the ignition or the like. [0168] Thus, the mixing device 112 generates mixed gas having 30 a temperature and an oxygen concentration appropriate for drying coal, and supplies the mixed gas to the drying process facility 300 as the drying air. For example, the mixing device 112 generates mixed gas having a temperature of 156'C and an oxygen concentration of 10 vol% or less, and then the mixed 35 gas is sent to the drying process facility 300 and used therein for drying coal, and after the drying process, the mixed gas has a temperature of about 70 0 C. [0169] In this way, the heat energies of the above exhaust gas and heat gas may be effectively used without being uselessly 5 wasted. In other words, the mixed gas maybe used in the drying process, thus achieving the effective heat use in the drying process facility 300, which may provide the size reduction and cost reduction of the drying process facility 300. [0170] 10 A portion of the exhaust gas that is not mixed with the heat gas by the mixing device 112 is supplied to the electric dust collector 107 such as a low temperature electric dust collector (EP). Then, after passing through the electric dust collector 107, the exhaust gas has its sulfur oxide (SOx) 15 removed by the desulfurization device 108, and then discharged into the atmosphere as exhaust gas. By the above process, the coal thermal power station 100 generates electricity. [0171] Note that the method for utilizing of exhaust gas 20 according to the eleventh embodiment may be configured to use, as the drying air to the drying process facility 300 for drying coal to be supplied to the coal thermal power station 100, both of the exhaust gas from the boiler 102 and the heat energy of the heat gas supplied from the cement manufacture facility 25 200 provided along with the power station 100, thus providing the effective use of the heat energy. [0172] Further, the method for utilizing of exhaust gas according to the eleventh embodiment is configured to be able 30 to use the heat gas from the clinker cooler 203 and the exhaust gas from the boiler 102 in the drying process in the drying process facility 300. [0173] Specifically, the heat gas discharged from the clinker 35 cooler 203 in the cement manufacture facility 200 is introduced to the mixing device 112 in the coal thermal power station 100, which mixes the heat gas with the exhaust gas from the boiler 102. Then, mixed gas having an oxygen concentration of 10 vol% or less is generated and supplied to the drying process facility 300. Therefore, the method 5 for utilizing of exhaust gas according to the eleventh embodiment may provide the effective use of the heat energy and an established technology to positively use the low grade fuel. [0174] 10 [Twelfth Embodiment] FIG. 19 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a twelfth embodiment of the present invention. With reference to FIG. 19, the method for utilizing of exhaust gas according to the twelfth 15 embodiment is different from the method according to the eleventh embodiment in that the exhaust gas to be mixed with the heat gas from the clinker cooler 203 by the mixing device 112 is exhaust gas passing through the heat recovery device 106 and the electric dust collector 107 by which the exhaust 20 gas has its temperature reduced and its ash content (dust) removed, respectively. [0175] Specifically, the exhaust gas from the boiler 102 is reduced in temperature by the heat recovery device 106, and 25 then supplied to the electric dust collector 107 that removes the ash content in the exhaust gas. Then, the exhaust gas from the electric dust collector 107 and the heat gas from the clinker cooler 203 are introduced to the mixing device 112 to generate mixed gas having a predetermined temperature 30 and an oxygen concentration as described above. The mixed gas is then supplied to the drying process facility 300. This may also provide, like the eleventh embodiment, the effective use of the heat energy and an established technology to positively use the low grade fuel. This may also provide the 35 optimized operations of each device and each process in the coal thermal power station 100.

[0176] [Thirteenth Embodiment] FIG. 20 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to thirteenth 5 embodiment of the present invention. FIG. 21 shows the detailed configuration of FIG. 20. With reference to FIG. 20 and FIG. 21, the method for utilizing of exhaust gas according to the thirteenth embodiment is different from the method according to the eleventh embodiment in that instead 10 of the desulfurization device 108 of the coal thermal power station 100, the desulfurizing agent supply device 10 is provided to desulfurize the exhaust gas in the combustion furnace 20 of the boiler 102 (internal furnace desulfurization). A desulfurization facility may be 15 provided in the subsequent stage. [0177] The desulfurizing agent 15 may be injected into the vicinity position of the upper nose section 21 as described above, thus performing the efficient desulfurization in the 20 combustion furnace 20 and decreasing the usage of the desulfurizing agent 15. After having its SO 2 and SO 3 removed in the combustion furnace 20 as described above, the exhaust gas is discharged from the combustion furnace 20 through the flue 22. Then, after, for example, passing through the above 25 denitrification device 105 to be denitrified and passing through the heat recovery device 106 to be reduced in temperature (the temperature is reduced), the exhaust gas is introduced in the mixing device 112. [0178] 30 In the thirteenth embodiment, it is preferable that the desulfurizing agent 15 injected into the vicinity of the upper nose portion 21 in the combustion furnace 20 removes SO 3 in exhaust gas in advance. Thus, the sulfuric acid dew point of the exhaust gas may be drastically reduced. The inventors 35 have demonstrated that specifically, the exhaust gas may thus be cooled to a temperature of, for example, about 90'C by the heat recovery device 106, thereby increasing the heat recovery amount and thus significantly improving the energy efficiency. [0179] 5 Further, as described above, each device such as the mixing device 112 may not be made of expensive corrosion resistant materials. For example, the material of portions in contact with the exhaust gas, such as the control valve and the conduit in the mixing device 112, may be made of an 10 inexpensive carbon steel (carbon steel) material, or the like. In the method for utilization of exhaust gas according to the thirteenth embodiment, the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 in the combustion furnace 20 removes SO3. 15 [0180] Then, the heat recovery device 106 is provided between the combustion furnace 20 and the collection device 109 to reduce the temperature of the exhaust gas discharged from the combustion furnace 20. The concentration of S03 in the 20 exhaust gas may thus not be enough to affect the collection performance of the electric dust collector, thereby maintaining and improving the collection performance. [0181] [Fourteenth Embodiment] 25 FIG. 22 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a fourteenth embodiment of the present invention. FIG. 23 shows the detailed configuration of FIG. 22. With reference to FIG. 22 and FIG. 23, the method for utilizing of exhaust gas 30 according to the fourteenth embodiment is different from the method according to the twelfth embodiment in that instead of the desulfurization device 108 of the coal thermal power station 100, the desulfurizing agent supply device 10 is provided to perform the internal furnace desulfurization of 35 the exhaust gas in the combustion furnace 20 of the boiler 102.

[0182] Note that the desulfurization process of the exhaust gas in the combustion furnace 20 of the boiler 102 is similar to that described above, and thus further description is omitted 5 here. This may also provide, like the twelfth embodiment, the effective use of the heat energy and an established technology to positively use the low grade fuel. This may also provide the optimized operation of each device and each process in the coal thermal power station 100. 10 [0183] [Fifteenth Embodiment] FIG. 24 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to a fifteenth embodiment of the present invention. With reference to FIG. 15 24, the method for utilizing of exhaust gas according to the fifteenth embodiment is applied to the drying process facility 300 mainly for drying coal provided as the low grade fuel and the coal thermal power station 100 using the dried coal supplied from the drying process facility 300 for the 20 combustion. [0184] The coal thermal power station 100 comprises the denitrification device 105, an air preheater 106a, the electric dust collector 107, and the desulfurization device 25 108. The denitrification device 105 may be arbitrarily installed. Note that in the fifteenth embodiment, the coal thermal power station 100 is configured to comprise the cement manufacture facility 200 provided along with it. Heat gas is introduced in the boiler 102 as a portion of the combustion 30 air and is used for the combustion therein. Preferably, the ratio of the heat gas as the combustion air introduced in the boiler 102 is about 10% to 25%. [0185] The exhaust gas from the boiler 102 is also distributed 35 by, for example, the distribution device 111, and used to dry coal in the drying process facility 300. The exhaust gas may D 0 be used for drying grinding coal in the grinding device 101. This provides a configuration that may totally perform the effective use of the heat energy of the exhaust gas. [0186] 5 Note that a portion of the dried coal may be used in a heat-using facility (for example, the cement manufacture facility 200) other than the boiler 102. The ground coal is combusted along with an oxygen-containing gas and the above heat gas in the combustion furnace 20 of the boiler 102 (for 10 example, see FIG. 26) . Note that the heat gas introduced in the boiler 102 has, for example, an oxygen concentration of 15 vol% or more and a temperature of 250 0 C or more. [0187] Meanwhile, the exhaust gas generated in the boiler 102 15 is discharged at a temperature of, for example, about 300'C to 400 C, and then distributed by the distribution device 111 in the subsequent stage. The distribution device 111 comprises a not-shown control valve and a conduit, and distributes and supplies some of the exhaust gas to the drying 20 process facility 300 and the grinding device 101. Further, the rest of the exhaust gas has its nitrogen oxide (NOx) removed by the denitrification device 105. [0188] In the fifteenth embodiment, the exhaust gas distributed 25 by the distribution device 111 and supplied to the drying process facility 300 has an oxygen concentration of, for example, 10 vol%. Further, after passing through the denitrification device 105, the exhaust gas is introduced in the air preheater 106a, where the exhaust gas is used to heat 30 the air, and is then supplied to the electric dust collector 107. After being heated by the air preheater 106a, the heated air is introduced to the boiler 102. Note that in the drying process facility 300, exhaust gas used as the drying air having too high temperature (i.e., drying air having a temperature 35 higher than the temperature of the firing point of coal) or exhaust gas having a too high oxygen concentration increases d / the possibility of the ignition or the like. [0189] Thus, the heat gas from the clinker cooler 203 that has a high oxygen concentration and a high temperature is not 5 directly introduced to the drying process facility 300. Instead, the heat gas is reduced in oxygen concentration in the boiler 102 and then discharged as the exhaust gas, and a portion of the heat gas is supplied to the drying process facility 300 as the drying air. For example, the exhaust gas 10 having a temperature of 378 0 C and an oxygen concentration of 10 vol% or less at the distribution device 111 is sent to the drying process facility 300, where the exhaust gas is used for drying coal. The exhaust gas after the drying process has a temperature of about 70 0 C. 15 [0190] As described above, the heat energy of the above exhaust gas and heat gas may be effectively used without being uselessly wasted. In other words, the heat gas may be used in the combustion in the boiler 102 as a portion of the 20 combustion air, thus eliminating the necessity of providing a separate heat recovery device to raise the temperature of the external air and of using the air as the combustion air, thereby increasing the energy efficiency and decreasing the facility cost. 25 [0191] Further, the exhaust gas after the combustion in the boiler 102 may be used in the drying process in the drying process facility 300 to provide the effective use of the heat in the drying process facility 300 as well as the size 30 reduction and cost reduction of the drying process facility 300. Therefore, the fifteenth embodiment may provide the effective use of the heat energy. Note that the exhaust gas after passing through the air preheater 106a is supplied to the electric dust collector 107. 35 [0192] Note that the method for utilizing of exhaust gas Zo according to the fifteenth embodiment uses, as the drying air to the drying process facility 300 for drying coal to be supplied to the coal thermal power station 100, the exhaust gas from the boiler 102. Further, the method according to 5 the fifteenth embodiment may also be configured to use, as the combustion air to the boiler 102, the heat gas supplied from the cement manufacture facility 200 provided along with the power station 100 and the heated air from the air preheater 106a, thus providing the effective use of the heat energy. 10 [0193] The clinker cooler 203 in the cement manufacture facility 200 discharges, as described above, heat gas having a temperature of 2500C or more, for example, about 3000C and an oxygen concentration of 15 vol% or more. However, the heat 15 energy of the heat gas has been unused and almost just discharged, as described above. Thus, the method for utilizing of exhaust gas according to the fifteenth embodiment may be configured to use the heat gas in the combustion process in the boiler 102 and the exhaust gas from the boiler 102 in 20 the drying process in the drying process facility 300. [0194] Specifically, the heat gas discharged from the clinker cooler 203 in the cement manufacture facility 200 is introduced in the boiler 102 of the coal thermal power station 25 100 for the combustion. Then, the exhaust gas from the boiler 102 having an oxygen concentration of 10 vol% or less is supplied to the drying process facility 300 via the distribution device 111. Therefore, the method for utilizing of exhaust gas according to the fifteenth embodiment may 30 provide the effective use of the heat energy and an established technology to positively use the low grade fuel. [0195] Further, the exhaust gas supplied to the drying process facility 300 may be distributed and supplied from a desired 35 location as appropriately such as a location after the denitrification device 105 in the subsequent stage of the boiler 102, a location after the electric dust collector 107, or a location after the desulfurization device 108. In this case, the distribution device 111 may be installed between each device. 5 [0196] [Sixteenth Embodiment] FIG. 25 is a block diagram of the entire flow of a method for utilizing of exhaust gas according to the sixteenth embodiment of the present invention. FIG. 26 shows the 10 detailed configuration of FIG. 25. With reference to FIG. 25 and FIG. 26, the method for utilizing of exhaust gas according to the sixteenth embodiment is different from the method according to the fifteenth embodiment in that the coal thermal power station 100 comprises the desulfurizing agent 15 supply device 10 to perform the desulfurization of the exhaust gas in the combustion furnace 20 of the boiler 102 (internal furnace desulfurization). [0197] The sixteenth embodiment is also different from the 20 fifteenth embodiment in that the distribution device 111 is provided in the subsequent stage of the air preheater 106a, and the heat recovery device 106 is provided in the subsequent stage of the distribution device 111. In this way, the method according to the sixteenth embodiment may provide a more 25 optimized operation of each device and each process in the coal thermal power station 100 than the method according to the fifteenth embodiment. Depending on the amount of the heat gas, the combustion air may be converted to the heat gas up to the total amount of the combustion air. The preheat of 30 the exhaust gas at the outlet of the air preheater 106a may be recovered, after passing through the distribution device 111, by the heat recovery device 106, and then be used by the water supply heater 104 to heat the water supply up to the total amount of the heat. 35 [0198] After having its S02 and SO 3 removed in the combustion ou furnace 20, the exhaust gas is discharged from the combustion furnace 20 through the flue 22. Then, after, for example, the exhaust gas passes through the above denitrification device 105 and is denitrified therein, some of the exhaust 5 gas is sent to the drying process facility 300 by the distribution device 111 in the subsequent stage of the air preheater 106a. Further, the rest of the exhaust gas passes through the heat recovery device 106 that recovers its heat, and is then sent to the electric dust collector 107. 10 [0199] In the sixteenth embodiment, it is preferable that the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 in the combustion furnace 20 removes SO 3 in the exhaust gas in advance. The inventors have 15 demonstrated that the sulfuric acid dew point of the exhaust gas may thus be drastically reduced, thereby increasing the heat recovery amount and thus significantly improving the energy efficiency. [0200] 20 Further, as described above, each device in the subsequent stage of the combustion furnace 20 may not be made of expensive corrosion resistant materials. For example, the material of portions in contact with the exhaust gas may be made of an inexpensive carbon steel (carbon steel) material, 25 or the like. In the method for utilizing of exhaust gas according to the sixteenth embodiment, the desulfurizing agent 15 injected into the vicinity position of the upper nose section 21 in the combustion furnace 20 removes SO 3 . [0201] 30 Therefore, the reduction of the temperature of the exhaust gas discharged from the combustion furnace 20, which is the above (1) element of the collection performance of the electric dust collector, may reduce the volume of the exhaust gas and also reduce the flow rate of the exhaust gas. Thus, 35 the concentration of SO 3 in the exhaust gas may not be enough to affect the collection performance of the electric dust b I collector, thereby maintaining and improving the collection performance. Note that the exhaust gas discharged from the electric dust collector 107 is desulfurized again by the desulfurization device 108 if necessary, and then transferred 5 by the blower 48 and discharged into the atmosphere through the stack 49. [Examples] [0202] With reference to some examples, the desulfurization 10 process of the exhaust gas will be specifically described below. In the examples, the boiler 102 in the coal thermal power station 100 shown in FIG. 8 or the like is a boiler having a vapor generation amount of 80 t/h. Coal (pulverized coal) used as the fuel is supplied to the boiler 102 along with the 15 air. [0203] The used desulfurizing agent 15 is cement factory dust recovered from the cyclone exhaust gas of the mill 201 of the above described cement manufacture facility 200. A chemical 20 composition of the cement plant dust is measured by the X-ray Fluorescence Analysis. The measurement result shows that CaO has 60.6 mass%, SiO 2 has 20.8 mass%, and A1 2 0 3 has 10.3 mass% by mass. Further, the used cement plant dust has a mass based average particle size of about 2pm. 25 [0204] In the following examples 1 and 2, the injecting position of the desulfurizing agent 15 is at a inside the furnace. In the example 3, the injecting position of the desulfurizing agent 15 is at s inside the furnace. The injecting positions 30 at a in the furnace comprises 4 positions of A, B, C, and D that are at a height 0.8 M above a vertex of the nose section 21 shown in FIG. 27(a) (a vertex of a triangle of the nose section 21 in FIG. 8 or the like), and 3 positions of E, F, and G that are at a height 0.4 L below the vertex of the nose 35 section 21 shown in FIG. 27 (b) (total of 7 positions). [0205] On the other hand, the injecting positions at s in the furnace comprises 3 positions of E, F, and G that are at a height 0.4 L below the vertex shown in FIG. 27(b). In FIG. 27(a), the desulfurizing agent 15 is supplied avoiding 5 positions where the overheater 20b is present. B and C in FIG. 27(a) are positioned intermediate between a central point and end points of a side surface. Moreover, E, F, and G in FIG. 27(b) are positioned at respective center-line portions of each of side surfaces of the combustion furnace 20. 10 [0206] The table 1 below shows S03 measurement results obtained in the examples. Note that S03 is measured at an inlet of the electric dust collector 107. [0207] 15 [Table 1] Desulfurizing Agent SOx S03 Blowing Concentration Concentration Type Position Ca/S (ppm) (ppm) Example 1 . 0.93 200 Less Than 0.05 Inside of Example 3 fu rnace 2.92 150 Less Than 0.05 [0208] (Example 1) In the example 1, the cement plant dust was injected into 20 the furnace with such that an SOx concentration of S02 + SO 3 within the combustion furnace 20 was 200 ppm, and a Ca/S molar ratio was 0.93. As a result, the SO 3 concentration was less than 0.05 ppm. [0209] 25 (Example 2) In the example 2, when an SOx concentration within the combustion furnace 20 was 180 ppm and a Ca/S molar ratio of the cement plant dust injected into the furnace was 2.06, an

SO

3 concentration was less than 0.05 ppm similarly to in the example 1. [0210] (Example 3) In the example 3, when an SOx concentration within the 5 combustion furnace 20 was 150 ppm and a Ca/S molar ratio of the cement factory dust injected into the furnace was 2.92, an SO 3 concentration was less than 0.05 ppm similarly to in the examples 1 and 2. Note that in each of the examples 1, 2, and 3, when the cement plant dust was not injected into 10 the combustion furnace 20, the SOx concentrations in the furnace 20 were the same as respective concentrations before the desulfurization. [0211] Using the above results, estimation of the heat balance 15 revealed that the fuel treatment system 1 and the method for utilizing of exhaust gas according to the above embodiments might reduce the sulfuric acid dew point of the exhaust gas to be set from about 126 0 C to less than 88 0 C. It was then revealed that the corrosion due to SO 3 condensation might be 20 suppressed even if, for example, the gas-water heat exchanger 121 as the first heat-exchange means of the indirect heat exchange mechanism 110 downstream of the heat recovery device 106 shown in FIG. 9 recovered heat corresponding to 50'C from the exhaust gas having a temperature of about 150'C when 25 passing through the heat recovery device 106, and the heat exchanger 122 as the second heat-exchange means used the heat as the preheating source of the water W2 to the boiler 102. It was also confirmed that the corrosion due to the SO 3 condensation might be suppressed even if, for example, the 30 heat of the exhaust gas was used by the drying process facility 300 or used to heat the water supply to the boiler 102. It was also revealed that the corrosion due to the SO 3 condensation might be suppressed even if, for example, the mixed gas was generated by the mixing device 112 downstream 35 of the heat recovery device 106, and then used by the drying process facility 300. It was also revealed that the corrosion b4 due to the SO 3 condensation might be suppressed even if, for example, a portion of the exhaust gas was used in the drying process facility 300 downstream of the boiler 102. [0212] 5 Therefore, the heat exchange process by the indirect heat exchange mechanism 110 in FIG. 8 was performed. As heat medium, deionized water was used. The heat medium circulation amount was 80 t/h (for a boiler at the level of the main steam generation amount of 80 t/h) . Exhaust gas was 10 reduced in temperature from 150'C to 100'C by the gas-water heat exchanger 121 as the first heat-exchange means. The deionized water was raised in temperature from 55'C to 74'C by the gas-water heat exchanger 121. The deionized water as the heat medium heated by the gas-water heat exchanger 121 15 raised the temperature of the boiler water supply W2 from 48 0 C to 62.50C in the heat exchanger 122 as the second heat-exchange means. [0213] As described above, the treatment system 1 according to 20 the above embodiment may provide the effective use of the heat energy and the positive use of the low grade fuel. [0214] The treatment system 1 according to the above embodiments may also treat SO 3 in exhaust gas in a less 25 expensive and easier manner, effectively provide the effective use of the heat energy of the exhaust gas, and efficiently operate the power generation facility with less problems such as facility corrosion. 30 Description of reference numerals [0215] 1 treatment system 2 database (DB) 3 control unit 35 4 adjustment device 10 desulfurizing agent supply device 13, 48 blower 14 desulfurizing agent injecting inlet 15 desulfurizing agent 20 combustion furnace 5 20a wall section 20b overheater 21 nose section (upper nose section 22 flue 30 exhaust gas temperature reduction facility 10 31 gas air heater 33 water spray device 49 stack 50 circulation path 50A primary circulation path 15 50B secondary circulation path 51 line 100 coal thermal power station 101 grinding device 102 boiler 20 103 electric generator 104 water supply heater 105 denitrification device 106 heat recovery device 107 electric dust collector 25 108 desulfurization device 110 indirect heat exchange mechanism 111 distribution device 112 mixing device 113 mixing facility 30 121 gas-water heat exchanger 122 heat exchanger 200 cement manufacture facility 201 mill 202 calcination device 35 203 clinker cooler 204 mixing mill 300 drying process facility

Claims (5)

1. A fuel treatment system comprising: a drying process facility for drying fuel using heat gas; an adjustment device for adjusting a temperature of the heat gas and supplying the temperature-adjusted heat gas to the drying process facility; and a control unit for controlling the adjustment device on the basis of data relating to a moisture amount and a temperature of a firing point of the fuel, wherein the fuel comprises coal or biomass, and the control unit controls drying so that the moisture content of the fuel is 1.3 times or less of an equilibrium moisture content thereof.

2. The fuel treatment system according to claim 1, wherein: the control unit controls drying so that the moisture content of the fuel is 1.2 times or less of an equilibrium moisture content thereof.

3. The fuel treatment system according to claim 1 or 2, wherein the heat gas has an oxygen concentration of 15 vol% or more and a temperature of 2500C or more.

4. The fuel treatment system according to any one of the preceding claims, wherein the heat gas is discharged from a clinker cooler of a cement manufacturing facility.

5. A fuel treatment system substantially as hereinbefore described with reference to the accompanying drawings. Ube Industries, Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON