DESCRIPTION Title of the Invention: CONCENTRATION PLANT, PLANT FOR PRODUCING FRESH WATER BY CONCENTRATION AND FOR GENERATING ELECTRIC POWER, CONCENTRATION METHOD, AND METHOD FOR OPERATING PLANT FOR PRODUCING FRESH WATER BY CONCENTRATION AND FOR GENERATING ELECTRIC POWER Technical Field [0001] The present invention relates to a concentration plant and a concentration method which separate raw water such as brine water or seawater, especially accompanying water released together with coal-bed gas from a coal bed into fresh water and a saline solid material, and to a plant that includes a concentration plant, produces fresh water by concentration and generates electric power, and a method for operating the plant. Background Art [0002] In recent years, methane-containing coal bed gas (hereinafter referred to as CBM) that is secondarily released from a coal bed upon mining of coal is becoming widely used. According to Non-Patent Document 1, water (hereinafter referred to as accompanying water) that exists in the coal bed is released upon extraction of CBM. The accompanying water is salt-containing brine water in many cases. It is necessary to return the accompanying water in a geological layer again under pressurization or separate salt from the accompanying water by desalination and place the accompanying water back into soil. Since the amount of the accompanying water varies due to a variation in the extraction amount of CBM, the performance in treating the accompanying water may limit an increase in the extraction amount of CBM. Currently, accompanying water is treated by an evaporation pond method in many CBM production facilities. In the evaporation pond method, the accompanying water is stored in a pond, water is removed by natural evaporation, and concentrated salt is separated as a solid material from the accompanying water. [0003] One of general methods for concentrating and separating salt is based on an evaporation concentration method using a multiple-effect evaporator or the like described in Patent Document 1. [0004] With the spread of deficiency of water, scheme of desalinating accompanying water to produce and use fresh water is in progress. According to Non-Patent Document 2, as main desalination methods, a membrane method for separating salt using a reverse osmosis membrane and an ion exchange membrane and an evaporation method for heating and evaporating water and condensing the water have been discussed so far. According to Non-Patent Document 3, there 2 is a case where fresh water is produced from accompanying water by a two-stage reverse osmosis membrane process. [0005] In the field of production of fresh water from seawater, a method in which a reverse osmosis membrane is combined with an evaporation method is used in order to increase the efficiency of producing fresh water, with the method being called a hybrid method. In Patent Document 2, in a pretreatment device, after a first stage nanofiltration membrane unit filters salt water so as to reduce the content of ions including scale components, the water is supplied to a reverse osmosis membrane device, where filtrate water (fresh water) is generated. On the other hand, discharge water that is not passed through the first stage nanofiltration membrane unit is supplied to a second stage filtration membrane unit, where a concentrated part of the discharge water is discharged to the outside of the system. Second stage nano-filtered water is supplied to a desalination device using an evaporation method, which generates fresh water with high efficiency while suppressing precipitation of a scale component. The concentrated water separated by the reverse osmosis membrane device is released through a valve or supplied together with the second stage nano-filtered water to the desalination device. Then, the desalination device uses the evaporation method to generate fresh water. Prior Art Document 3 Patent Document [0006] Patent Document 1: JP-2004-41850-A Patent Document 2: JP-2008-100219-A Non-patent Document [0007] Non-Patent Document 1: Shigeki Sakamoto, Yasunobu Ohno, Oil/Natural Gas Review, Vol. 42, No. 6, p 31-49 (2008) Non-Patent Document 2: James R Kuipers et al. Coal Bed Methane-Produced Water: Management Options for Substainable Development, pages 52-58, August 2004 Non-Patent Document 3: James Welch, the edition of OIL & GAS JOURNAL, October 5 (2009) Summary of the Invention Problem to be Solved by the Invention [0008] Currently, as a method for treating accompanying water (salt-containing brine water) released upon extraction of CBM, such an evaporation pond method as described in Non Patent Document 1 is used in many CBM production facilities. In this case, a large site, however, is required. [0009] As described in Patent Document 1, Non-Patent Document 2 and Non-Patent Document 3, a membrane method and 4 an evaporation method have been discussed as treatment methods to be used instead of the evaporation pond method and are currently used in some of facilities. Especially, in Non-Patent Document 3, accompanying water is concentrated by the two-stage reverse osmosis membrane process, whereby the volume of the water is reduced. In this case, the volume of the concentrated water after separation of fresh water is reduced to approximately one tenth the volume of the supplied accompanying water. The volume of an evaporation pond used to separate salt from the concentrated water can also be reduced to one tenth. Even if the volume is reduced, however, an evaporation pond to solidify and separate salt is necessary to provide. Thus, there are problems with high facilities cost for a wide area for providing the evaporation pond and a limitation on location requirements. When an evaporation concentration device is used, the volume of a facility can be significantly reduced compared with the evaporation pond, but a heat resource for heating is required and its operation cost increases. [0010] In Patent Document 2, the reverse osmosis membrane and the evaporation method are combined in order to increase the efficiency of producing fresh water. A part (water concentrated in the second stage filtration membrane unit) of pretreated waste water is discarded to the outside, while also concentrated water separated by the reverse osmosis membrane device is discarded to the outside if necessary. Even if such a technique is applied to the treatment of 5 H:\mas\Intensoven\NRPonbl\DCC\MAS\6I4676_ I doc-15/05/2014 -6 accompanying water, it is necessary to provide an evaporation pond used to solidify and separate salt after all. 5 [0011] Embodiments of the invention may provide a concentration plant and a concentration method which solve the aforementioned conventional problems, the concentration plant and the concentration method enabling salt-containing 10 water that is accompanying water or the like to be concentrated in a stable manner with low facilities cost and separated into fresh water and the salt by the combination of a desalination device based on a membrane method with a concentration device based on an evaporation method. 15 [0012] In embodiments of the invention, a concentration device includes a reverse osmosis membrane device that separates accompanying water released together with coal-bed 20 gas from a coal bed into filtrate water and non-permeated water; and an evaporation concentration device that concentrates the non-permeated water and discharges the concentrated water into a storage tank. [0013] 25 According to the present invention there is provided a plant for producing fresh water by concentration and for generating electric power, comprising: a gas turbine generator provided with a gas turbine that uses a carbon hydride as a main fuel; 30 a waste heat recovery boiler that generates steam using waste heat of the gas turbine; and a concentration device that concentrates raw water; H:\mlaslnienvven\NlKl'OrbIWl\UC\MA5\6146761_Idoc-15/05/2014 -7 wherein the concentration device includes a pretreatment device that pretreats the raw water, a reverse osmosis membrane device that separates the pretreated water that has passed through the pretreatment 5 device into filtrate water and non-permeated water, and an evaporation concentration device the concentrates pretreated waste water generated resulting from the pretreatment and the non-permeated water using steam generated by the waste heat recovery boiler as a heat 10 resource to thereby generate concentrated water; wherein the concentration device further includes a precipitation device that precipitates an inorganic component contained in the non-permeated water in a flow path through which the non-permeated water flows to the 15 evaporation concentration device; and wherein the precipitation device has a heater that heats the non-permeated water using steam generated by the waste heat recovery boiler as a heat resource. The invention also provides a plant for producing fresh 20 water by concentration and for generating electric power, comprising: a gas turbine generator provided with a gas turbine that uses a carbon hydride as a main fuel; a waste heat recovery boiler that generates steam using 25 waste heat of the gas turbine; and a concentration device that concentrates raw water; and wherein the concentration device includes a pretreatment device that pretreats the raw water, a reverse osmosis membrane device that separates the 30 pretreated water that has passed through the pretreatment device into filtrate water and non-permeated water, and an evaporation concentration device that concentrates H:\mas\InIenvOvNC\NRPorb\DCC\MAS\6146761 _ Idoc- 15/05/2014 -8 pretreated waste water generated resulting from the pretreatment and the non-permeated water using steam generated by the waste heat recovery boiler as a heat resource to thereby generate concentrated water; and 5 further comprising a steam supply system that injects the steam generated by the waste heat recovery boiler into a combustor of the gas turbine. The invention also provides a plant for producing fresh 10 water by concentration and for generating electric power, comprising: a gas turbine generator provided with a gas turbine that uses a carbon hydride as a main fuel; a waste heat recovery boiler that generates steam using 15 waste heat of the gas turbine; and a concentration device that concentrates raw water; wherein the concentration device includes a pretreatment device that pretreats the raw water, a reverse osmosis member device that separates the 20 pretreated water that has passed through the pretreatment device into filtrate water ad non-permeated water, and an evaporation concentration device that concentrates pretreated waste water generated resulting from the pretreatment and the non-permeated water using steam 25 generated by the waste heat recovery boiler as a heat resource to thereby generated concentrated water; wherein the concentration device further includes a precipitation device that precipitates an inorganic component contained in the non-permeated water in a flow 30 path through which the non-permeated water flows to the evaporation concentration device; and wherein the precipitation device has a device that :\aunt e 0rwovem n -, Wortoot AN\146 /6 L .doc- 1303/2014 -9 injects waste gas discharged from the gas turbine into the non-permeated water. [0014] 5 By arranging the reverse osmosis membrane device on the upstream side, while the evaporation concentration device is arranged on the downstream side. Thus, the raw water (accompanying water) can be concentrated by a combination of the devices arranged on the upstream and 10 downstream sides, whereby the volume of the raw water can be significantly reduced. As a result, after the concentrated water may be temporarily stored in the storage tank, the concentrated water may be evaporated to dryness. It is not necessary to provide an evaporation pond even when the 15 concentrated water is to be evaporated to dryness. Thus, the cost in constructing an evaporation pond may be avoided. Even if an evaporation pond is provided, the area necessary for providing the evaporation pond can be significantly reduced, and the cost in constructing the evaporation pond 20 can be reduced. [0015] When any of the configurations according to the invention is used, a site for equipment for treating accompanying water in a CBM production facility it may be 25 possible to reduce the site and facilities cost may be significantly reduced. In addition, waste substances can be reduced, and a stable operation can be achieved. [0016] By suppressing an increase in facilities cost and a 30 limitation on location requirements, it may be possible to flexibly handle a variation (caused by a variation in the amount of CBM to be extracted) in the amount of the H-1m5tilCT1 Vili- 'T0 1 \U LMA \14U0I DILGOC- I /UN/2D14 - 10 accompanying water, increase the performance of treating the accompanying water and increase the amount of the CBM to be extracted. [00171 5 Deleted [0018] Deleted [0019] In embodiments, the evaporation concentration device 10 generates the concentrated water using the steam generated by the waste heat recovery boiler as the heat resource, an energy cost for generation of steam in the evaporation concentration device is not required. Since the waste heat of the generator is used, resources in the overall 15 facilities can be efficiently used and operation cost may be reduced. [0020] It is preferable that the concentration device have a precipitator that precipitates an inorganic component 20 contained in the non-permeated water in a flow path through which the non-permeated water flows to the evaporation concentration device. It is preferable that the precipitator have one or more of a function of increasing pH of the non-permeated water, a function of increasing 25 carbonate ions, a heating function, a function of injecting a microscopic bubble and a function of injecting a calcium ion. [0021] In embodiments where insoluble salt is precipitated 30 in advance as microscopic crystal floating in the water, the insoluble salt may be grown as a core of the crystal in evaporators of the evaporation concentration device. As a H:\mias\lintenoven\NRPortb\DCC\MAS\6146761_l.doc-1510512014 -11 result, it may be possible to avoid precipitation and growth of a scale on wall surfaces of the evaporators and achieve a stable operation. In addition, the amount of an agent used for cleaning the insides of the evaporators and labor for 5 the cleaning may be reduced. [0022] It is preferable that the precipitator have a heater that heats the non-permeated water using the steam generated by the waste heat recovery boiler as the heat resource, or 10 the precipitator have a device that injects waste gas discharged from the gas turbine into the non-permeated water. [0023] Thus, precipitation of calcium carbonate and the 15 like may be promoted, and precipitation and growth of a scale on the wall surfaces of the evaporators of the evaporation concentration device are avoided. [0024] It is preferable in the case that the plant for 20 producing fresh water by concentration and for generating electric power, that the plant includes a steam supply system that injects the steam generated by the waste heat recovery boiler into a combustor of the gas turbine. In this case, it is preferable that the steam supply system 25 have a valve that adjusts the amount of steam, which is generated by the waste heat recovery boiler, to supply to the combustor. [0025] Since the steam is supplied to the combustor in the 30 aforementioned manner, a mass flow rate of combustion gas to be introduced into the turbine may be increased, whereby the amount of electric power to be generated by the generator -12 can be increased. If the amount of electric power to be generated by the generator does not need to be increased, the amount of fuel gas to be consumed may be reduced. [0026] 5 It is preferable that the plant for producing fresh water by concentration and for generating electric power include an indirect heat exchanger that uses steam generated by the waste heat recovery boiler to generate steam to be supplied to the evaporation concentration device. 10 [0027] Thus, a system that generates steam using the waste heat recovery boiler may be separated from a system that causes steam to flow into and out of the evaporation concentration device, to avoid mixture of salt into the 15 steam generated by the waste heat recovery boiler, and corrosion of the waste heat recovery boiler 2 may be limited. [0028] Deleted 20 [0029] Deleted [0030] Deleted [0031] 25 According to embodiments of the invention, it may be possible to reduce a site for equipment for treating accompanying water in a CBM production facility and significantly reduce facilities cost. In addition, it may be possible to reduce waste substances and achieve a stable 30 operation. Furthermore, since high facilities cost and a limitation on location requirements are suppressed, it may be possible to flexibly handle a variation (caused by a NI:\mfaS\fInvlIV1\N~Kf'oTnDULU\~M5\l46/61_I.dOC-15/05/20l4 -13 variation in the amount of CBM to be extracted) in the amount of accompanying water, increase the performance of treating the accompanying water and increase the extraction amount of the CBM. 5 [0032] In addition, according to embodiments of the invention, it may be possible to reduce the site for the equipment for treating accompanying water in a CBM production facility and achieve an operation which involves 10 a reduction in the amount of waste substances, while it may be possible to efficiently use resources in the overall facilities by using waste heat of the generator and reduce operation cost. The invention is further described by way of example 15 only with reference to the accompanying drawings in which: Fig. 1 is a schematic diagram illustrating the configuration of a concentration plant according to a first embodiment of the invention.
Fig. 2A is a schematic diagram illustrating an example of the configuration of a precipitator of the concentration plant according to the first embodiment of the invention. Fig. 2B is a schematic diagram illustrating another example of the configuration of the precipitator of the concentration plant according to the first embodiment of the invention. Fig. 2C is a schematic diagram illustrating still another example of the configuration of the precipitator of the concentration plant according to the first embodiment of the invention. Fig. 2D is a schematic diagram illustrating still another example of the configuration of the precipitator of the concentration plant according to the first embodiment of the invention. Fig. 3A is a diagram illustrating the operation and effect of the concentration plant according to the first embodiment of the invention. Fig. 3B is a diagram illustrating the operation and effect of a plant for producing fresh water by concentration and for generating electric power according to a second embodiment of the invention. Fig. 4 is a schematic diagram illustrating the configuration of the plant for producing fresh water by concentration and for generating electric power according to the second embodiment of the invention. 14 Fig. 5 is a schematic diagram illustrating the configuration of a plant for producing fresh water by concentration and for generating electric power according to a third embodiment of the invention. Fig. 6 is a schematic diagram illustrating the configuration of a plant for producing fresh water by concentration and for generating electric power according to a fourth embodiment of the invention. Mode for Carrying out the Invention [0034] Hereinafter, embodiments of the invention are described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same parts. First Embodiment [0034] Fig. 1 is a schematic diagram illustrating the configuration of a concentration plant according to a first embodiment of the invention. The present embodiment is an example in which accompanying water in a CBM production plant is treated as raw water. Brine water (for example, factory waste water, groundwater, salt lake water or the like) other than accompanying water may be treated as raw water. Seawater may be treated as raw water. [0035] Referring to Fig. 1, a brine water concentration plant of which an overall configuration is indicated by 15 reference numeral 100 includes pretreatment equipment 3, reverse osmosis membrane concentration equipment 4 (reverse osmosis membrane device), a storage tank 5, evaporation concentration equipment 6 (evaporation concentration device), a concentrated water tank 7, and a precipitator 10 (precipitation device). [00361 The pretreatment equipment 3 removes solid and soluble substances from accompanying water 20 or adjusts the temperature, pH and the like of the water, whereby the accompanying water 20 becomes pretreated water 21. The purpose of the pretreatment is to prevent calcium carbonate and the like from being concentrated and precipitated on a surface of a reverse osmosis membrane of the reverse osmosis membrane concentration equipment 4. Normally, the pH of the accompanying water 20 is in a range from 7 to less than 10. If the pH is to be adjusted in the pretreatment, the pH is adjusted to approximately 6 to 7, depending on the membrane to be used, the temperature of the water and the like. The pretreated water 21 flows into the reverse osmosis membrane concentration equipment 4 and is separated into filtrate water 22 and membrane-concentrated water 24. The filtrate water 22 is used as fresh water. The membrane-concentrated water 24 contains calcium carbonate, silica and the like that are components contained in the accompanying water 20. All parts of the membrane-concentrated water 24 flow into the precipitator 10, where an alkaline agent is mixed with the membrane-concentrated water 24 and insoluble components 16 such as the calcium carbonate are precipitated from the membrane-concentrated water 24. After that, the membrane concentrated water 24 flows into the storage tank 5. All parts of pretreated waste water 23 that contains the solid and soluble substances removed from the accompanying water 20 in the pretreatment device 3 flow into the storage tank 5, where the pretreated waste water 23 and the membrane concentrated water 24 are mixed with each other to form evaporation-concentrated supply water 25. All parts of the evaporation-concentrated supply water 25 flow into the evaporation concentration equipment 6, where the evaporation-concentrated supply water 25 is separated into condensed water 26 and evaporation-concentrated water 27. The condensed water 26 is used as fresh water. The evaporation-concentrated water 27 is stored in the concentrated water tank 7. While the reverse osmosis membrane concentration equipment 4 is arranged on the upstream side, the evaporation concentration equipment 6 is arranged on the downstream side. Thus, the volume of the water can be significantly reduced by concentrating the water on both upstream and downstream sides. As a result, the evaporation-concentrated water 27 stored in the concentrated water tank 7 can easily be treated. After that, preferably the evaporation-concentrated water 27 stored in the concentrated water tank 7 is evaporated to dryness at an appropriate time. [0037] 17 The evaporation concentration equipment 6 is a multiple-effect evaporator that includes a plurality of evaporators, for example. As the multiple-effect evaporator, the evaporator described in Patent Document 1 (JP-2004 41850-A) can be used. If the evaporation concentration equipment 6 has a plurality of evaporators, there may be a problem that insoluble salt is attached to inner wall surfaces of the evaporators as a scale. In the present embodiment, insoluble salt is precipitated by the precipitator 10 in advance as microscopic crystal floating in the water, and the insoluble salt is grown as a core of the crystal in the evaporators. As a result, it is possible to avoid precipitation and growth of a scale on wall surfaces of downstream-side evaporators and achieve a stable operation. In addition, the amount of an agent used for cleaning the insides of the evaporators and labor for the cleaning can be reduced. [00381 Examples of the configuration of the precipitator 10 are illustrated in Figs. 2A to 2D. In the example illustrated in Fig. 2A, the membrane-concentrated water 24 flows into a mixed water tank 40, where the water 24 is mixed with an alkaline agent added from chemicals injection equipment 41, and insoluble salt such as calcium carbonate is precipitated. As the alkaline agent, caustic soda or slaked lime can be used. Without the mixed water tank 40, the membrane-concentrated water 24 may be mixed with the alkaline agent in a pipe line. In this case, a line mixer 18 may be arranged. The calcium carbonate can easily be precipitated by injecting the alkaline agent and thereby adjusting the pH of the evaporation-concentrated supply water 25 to 8.5 or higher. If the pH is set to 8 or higher and an evaporation temperature is set to 400C or higher in the evaporation concentration equipment 6, then the solubility of the silica can be increased and the potential of generation of a silica scale can be reduced. Calcium ions may be injected instead of the alkaline agent. [0039] As illustrated in the example of Fig. 2B, a heating tank 42 (heater) may be arranged on the upstream side of the mixing of the alkaline agent to heat the membrane concentrated water 24. When the temperature of the water is increased, the solubility of the calcium carbonate is reduced and the precipitation of the calcium carbonate is promoted. Neither the mixed water tank 40 nor the line mixer is arranged and the heating tank 42 only may be arranged. In addition, as illustrated in the example of Fig. 2C, a C0 2 -containing gas 35 may be injected in a mixed water tank 40a arranged on the upstream side of the mixing of the alkaline agent. When the pH is adjusted to a slightly acidic level by solving the C02, the solubility of slaked lime increases, and the amount of calcium ions can be increased. Thus, the precipitation of the calcium carbonate can be promoted. In addition, as illustrated in the example of Fig. 2D, the membrane-concentrated water 24 that has flowed in a mixed water tank 40b is introduced in a 19 microscopic bubble generator 43, where a gas 36 containing air and CO 2 may be injected in the membrane-concentrated water 24 therein to generate microscopic bubbles with diameters of approximately 50 micrometers or less, followed by returning the microscopic bubbles to the mixed water tank 40b. In this case, a microscopic crystal core is generated due to rapid solution of the microscopic bubbles, whereby precipitation of insoluble salt can be promoted. [00401 In any case, in order that precipitated substances may not be precipitated in the mixed water tank 40 and pipe lines within the precipitator 10, desirably the precipitator 10 is designed such that flow rates of the water in the respective parts of the precipitator 10 are not lower than a predetermined value. The precipitator 10 may be arranged on the downstream side of the storage tank 5. [0041] Referring again to Fig. 1, the accompanying water 20 that has yet to flow into the pretreatment equipment 3, the filtrate water 22 or the condensed water 26 may be used for cooling water 28. When the accompanying water 20 is used as the cooling water 28, such use should desirably be made in the range in which the quality of the filtrate water 22 is maintained at a necessary level. The reason is that when, in the later stage, the accompanying water 20 is supplied to the pretreatment equipment 3 and treated in the reverse osmosis membrane concentration equipment 4, the permeability of salt in the reverse osmosis membrane concentration 20 equipment 4 will increase due to an increase in water temperature. [0042] When the filtrate water 22 is compared with the condensed water 26, the amount of salt contained in the filtrate water 22 is larger than the amount of salt contained in the condensed water 26. Thus, the filtrate water 22 and the condensed water 26 may be mixed with each other and used depending on a purpose of use. For example, it can be considered that the filtrate water 22 is used as a raw material of drinking water and the condensed water 26 is used as industrial water containing salt of which content is less. Using the accompanying water 20 as the cooling water 28 as described above means to warm the accompanying water 20 and thereby the amount of salt contained in the filtrate water 22 may increase. In this case, the quality of the water can be adjusted by mixing the warmed accompanying water 20 with the condensed water 26. [00431 Hereinafter, operation and effect that are obtained by the aforementioned configuration are described. [0044] Fig. 3A is a conceptual diagram describing effects of the present embodiment. The ordinate indicates estimated ratios of the cost of provision of an evaporation pond to that of a conventional evaporation pond method and a conventional reverse osmosis membrane concentration method. [0045] 21 If the facilities cost for the conventional evaporation pond method is 1, the amount of water treated in an evaporation pond in the conventional reverse osmosis membrane concentration method is reduced to approximately one tenth the amount of water used in the evaporation pond method in which the water is not concentrated; accordingly the cost of provision of the evaporation pond is also reduced. In the present embodiment, when the evaporation concentrated water 27 stored in the concentrated water tank 7 is evaporated to dryness, it is not necessary to provide an evaporation and thus the cost of provision of the evaporation pond is 0. In the present embodiment, an evaporation pond may be arranged as storage equipment instead of the concentrated water tank 7. In this case, the area necessary for providing the evaporation pond can be significantly reduced and the cost of provision of the evaporation pond can.be reduced. [0046] Since adopting the configuration according to the present embodiment allows reduction in the area of a site for equipment for treating accompanying water in CBM production facilities, the facilities cost can be significantly reduced. In addition, waste substances can be reduced, and a stable operation can be achieved. [0047] Since high facilities cost and a limitation on location requirements are suppressed, it is possible to flexibly handle a variation in the amount of the 22 accompanying water attributable to a variation in the extraction amount of CBM, increase the performance of treating accompanying water and increase the extraction amount of CBM. [0048] Since the precipitator 10 is arranged in a flow path through which the membrane-concentrated water 24 flows into the evaporation concentration equipment 6, it is possible to avoid precipitation and growth of a scale on the wall surfaces of the evaporators and achieve a stable operation. Moreover, the amount of an agent used for cleaning the insides of the evaporators and labor for the cleaning can be reduced. Second to Fourth Embodiments Fig. 4 is a schematic diagram illustrating a configuration of a plant for producing fresh water by concentration and for generating electric power according to a second embodiment of the invention. In the present embodiment, the concentration plant according to the first embodiment has gas turbine facilities arranged in parallel. [0049] Referring to Fig. 4, the plant for producing fresh water by concentration and for generating electric power includes a gas turbine generator 200, a waste heat recovery boiler 2 and a concentration device 300. The gas turbine generator 200 has a gas turbine 1 that uses as a main fuel LNG such as carbon hydride. The waste heat recovery boiler 2 generates steam using waste heat of the gas turbine 23 generator 200. As the concentration device 300, the concentration plant 100 according to the first embodiment is used, for example. [0050] In the gas turbine generator 200, the gas turbine 1 includes a compressor la, a turbine 1b, a combustor 8, a power generator 9, and a waste gas treatment tower 12. Air 30 compressed by the compressor la becomes compressed air 30a. Then, the compressed air 30a flows in the combustor 8 and is mixed with fuel gas 33. The fuel gas 33 is burned in the combustor 8 to form combustion gas, by which the turbine 1b is rotated, the combustion gas flows out of the combustor 8 as waste gas 31. Upon receiving torque from the turbine 1b, the power generator 9 generates electricity. The waste gas 31 flows into the waste heat recovery boiler 2, which generates steam using waste heat, and thereafter the waste gas 31 is delivered to the waste gas treatment tower 12. The waste gas 31 is treated by the waste gas treatment tower 12 and released into an atmosphere. [0051] A heat exchanger 2a for a first steam supply system 32A is arranged within the waste heat recovery boiler 2. Water circulates in the first steam supply system 32A. The waste gas 31 introduced in the waste heat recovery boiler 2 supplies heat to the circulating water through the heat exchanger 2a, with the circulating water being phase-changed to steam 32. The steam 32 flows into the evaporation concentration equipment 6 and heats the evaporation 24 concentrated supply water 25, so that the evaporation concentrated supply water 25 is phase-changed to steam. The generated steam is cooled by the cooling water 28 to form the condensed water 26. The steam 32 loses heat and is restored to the circulating water. [0052] The concentration device 300 (concentration plant 100) is constituted similar to the first embodiment. Specifically, the pretreatment equipment 3 removes solid and soluble substances from accompanying water 20 or adjusts the temperature, pH and the like of the water, whereby the accompanying water 20 becomes pretreated water 21. The pretreated water 21 flows into the reverse osmosis membrane concentration equipment 4 and is separated into the filtrate water 22 and the membrane-concentrated water 24. The filtrate water 22 is used as fresh water. The membrane concentrated water 24 flows into the precipitator 10, where the membrane-concentrated water 24 is mixed with the alkaline agent, and an insoluble component is precipitated. After that, the membrane-concentrated water 24 flows into the storage tank 5. The pretreated waste water 23 that contains the solid and soluble substances removed from the accompanying water 20 by the pretreatment equipment 3 flows into the storage tank 5, where the pretreated waste water 23 and the membrane-concentrated water 24 are mixed with each other to form the evaporation-concentrated supply water 25. The evaporation-concentrated supply water 25 flows into the evaporation concentration equipment 6 and is separated into 25 C:NRPorb\DCC\MASW853199 I DOC-10/01/20I13 -26 the condensed water 26 and the evaporation-concentrated water 27. The condensed water 26 is used as fresh water. The evaporation-concentrated water 27 is stored in the concentrated water tank 7. 5 [0053] If the heating tank 42 illustrated in the example of Fig. 2B is arranged in the precipitator 10, the waste gas 31 from the gas turbine 1 may be used as a heat resource for the heating tank 42. In addition, the waste gas 31 from the 10 gas turbine 1 may be used as the C0 2 -containing gas 35, 36 described in the examples of Figs. 2C and 2D. The waste gas 31 may be supplied to the precipitator 10 after being heat exchanged by the waste heat recovery boiler 2. Fig. 4 illustrates an example in which the waste gas 31 that has 15 been heat-exchanged by the waste heat recovery boiler 2 is supplied to the precipitator 10. [0054] Electric power generated by the power generator 9 may be used as a power resource for the pretreatment 20 equipment 3 and the reverse osmosis membrane concentration equipment 4. In addition, LNG produced from CBM can be used as the fuel gas 33. In this manner, energy loss in transmission and transportation cost can be reduced by using raw materials and energy that exist in the plant. 25 [0055] An example (third embodiment) in which heat of the steam 32 is supplied through an indirect heat exchanger 13 to the evaporation concentration equipment 6 is illustrated in Fig. 5. If the steam 32 is directly supplied to the evaporation concentration equipment 6, salt derived from the evaporation-concentrated supply water 25 may be mixed into the steam that has flowed into the evaporation concentration equipment 6, depending on the structure of the evaporation concentration equipment 6. In the example illustrated in Fig. 5, a first steam supply system includes a primary steam supply system 32B, a secondary steam supply system 32C and the indirect heat exchanger 13. The primary steam supply system 32B has a heat exchanger 2a. The secondary steam supply system 32C supplies steam to the evaporation concentration equipment 6. The indirect heat exchanger 13 uses the steam of the primary steam supply system 32B to supply heat to water circulating in the secondary steam supply system 32C and thereby generates steam. Since the system 32B for the steam 32 is separated from the system 32C for steam that flows in and out of the evaporation concentration equipment 6, salt is not mixed into the steam 32, thereby making it possible to avoid corrosion of the waste heat recovery boiler 2. [0056] Fig. 6 illustrates an example (fourth embodiment) in which steam generated by the waste heat recovery boiler 2 is injected in the combustor 8. In this example, the heat resource generated by the waste heat recovery boiler 2 is used as a heat resource for the heating tank 42 (illustrated in Fig. 2B) for the precipitator 10. [0057] 27 C:NRPobrCC\MAS\4853 9I DOC- 111/20 f 13 -28 Referring to Fig. 6, the heat exchanger 2a for the first steam supply system 32A, a heat exchanger 2b for a heat resource supply system 210A and a heat exchanger 2c of a secondary steam supply system 34A are arranged within the 5 waste heat recovery boiler 2. In the waste heat recovery boiler 2, the steam 32 sent to the evaporation concentration equipment 6, a heat resource 210 sent to the heating tank 42 for the precipitator 10, and steam 34 sent to the combustor 8 are separately generated. Heating media of the heat 10 resource 210 corresponding to the heating tank 42 for the precipitator 10 may be steam and water or warm water and cold water. In addition, a substance other than water may be used. A valve 11 that is normally closed is arranged in a pipe line in which the steam 34 of the primary steam 15 supply system 34 flows. When the valve 11 is open, the steam 34 is supplied to the combustor 8. When the steam 34 is supplied to the combustor 8, a mass flow rate of combustion gas introduced into the turbine lb increases. Thus, the amount of electric power generated by the power 20 generator 9 can be increased. If the amount of electric power generated by the power generator 9 does not need to be increased, the fuel gas 33 can be reduced in consumption. The steam 34 is mixed into the waste gas 31 and released into an atmosphere through the waste heat recovery boiler 2 25 and the waste gas treatment tower 12. Since the filtrate water 22 and the condensed water 26 are generated as fresh water in the concentration device 300, water is supplied to the heat exchanger 2c within the waste heat recovery boiler 2 using the filtrate water 22 and the condensed water 26. Fig. 6 illustrates an example in which a part of the condensed water 26 is extracted and supplied to the heat exchanger 2c. In addition, a purifying device (not illustrated) may be arranged in the case where the available purity of fresh water is low. [0058] The present embodiment is very effective for the treatment of accompanying water released upon extraction of CBM. A carbon hydride such as methane produced from CBM can be used as the fuel of the gas turbine 1. Electric power generated by the gas turbine 1 can be used in the concentration device 100. Surplus electric power can also be supplied to an external device. The density of accompanying water released upon extraction of CBM is as small as approximately one fifth the density of seawater, and osmotic pressure of the accompanying water is low. Thus, according to the invention, electric power consumed by the reverse osmosis membrane concentration equipment 4 can be maintained at a low level with the reverse osmosis membrane concentration equipment 4 arranged on the upstream side and the evaporation concentration equipment 6 arranged on the downstream side. The steam 32 to be supplied to the evaporation concentration equipment 6 can be generated from the waste heat of the gas turbine 1. In addition, the accompanying water can be concentrated by the equipment arranged on the upstream and downstream sides, whereby the volume of the water can be significantly reduced. 29 Furthermore, the electric power and waste heat from the gas turbine 1 can be utilized. [0059] The accompanying water released upon the extraction of the CBM contains a larger amount of carbonates than seawater, with the carbonate being an underground rock component. If the temperature of the accompanying water is increased, the carbonate is precipitated and contaminates a heat-transfer surface in the evaporation concentration equipment 6. In order to avoid this, the precipitator 10 is provided with the heating tank 42 to heat the accompanying water using the heat resource 210, so that the carbonate is precipitated and separated, whereas the concentrated water is sent to the evaporation concentration equipment 6. The waste heat from the gas turbine 1 is used also as the original heat resource for the heat resource 210. [0060] The opening degree of the valve 11 is adjusted on the basis of a variation in the amount of the accompanying water to be treated, a variation in the amount of electric power for supply and the like. For example, to make small the amount of the accompanying water to be treated and increase the amount of electric power for supply, the valve 11 is opened so as to send the great amount of the steam 34 to the combustor 8. In this case, a large amount of heat collected by the waste heat recovery boiler 2 is consumed for generation of the steam 34, so that the amount of heat that 30 is used for the steam 32 and the heat resource 210 are reduced. [0061] The following explains the operation and effect of the aforementioned configuration in which the gas turbine generator 200 and the waste heat recovery boiler 2 are arranged in the concentration device 300 in parallel. [0062] Fig. 3B is a conceptual diagram describing the effects of the present embodiment. The ordinate indicates estimated ratios of operation cost of the concentration plant to the conventional evaporation pond method and the conventional reverse osmosis membrane concentration method. [0063] Since solar concentration is performed in the conventional evaporation pond method, its operation cost is 0, whereas if the conventional reverse osmosis membrane concentration method is adopted, it requires the operation cost that includes a cost for electric power consumed by reverse osmosis membrane concentration equipment and a cost for exchanging a membrane. [0064] For the configuration of the concentration plant only, the concentration is performed at the two stages. Thus, a concentration rate in the reverse osmosis membrane concentration equipment 4 can be reduced. The energy cost for the generation of steam in the evaporation concentration equipment 6, however, is required. In contrast, for the 31 configuration in which the gas turbine generator 200 and the waste heat recovery boiler 2 are arranged in parallel according to the present embodiment, the steam is supplied from the waste heat recovery boiler 2, and thus the energy cost for the generation of steam in the evaporation concentration equipment 6 is not required. [0065] With the configuration according to the present embodiment as described above, a site for equipment for treating accompanying water in a CBM production facility can be reduced, and an operation which involves a reduction in the amount of waste substances can be achieved. Moreover, since the waste heat of the generator is used, resources in the overall facilities can be efficiently utilized, leading to a reduction in operation cost. Description of Reference Characters [0066] 1 -- Gas turbine la "* Compressor lb "' Turbine 2 - Waste heat recovery boiler 2a, 2b, 2c "- Heat exchanger 3 " Pretreatment equipment 4 -- Reverse osmosis membrane concentration equipment (reverse osmosis membrane device) 5 "' Storage tank 32 6 "' Evaporation concentration equipment (evaporation concentration device) 7 "- Concentrated water tank 8 -- Combustor 9 - Power generator 10 "- Precipitator (precipitation device) 11 Valve 12 Waste gas treatment tower 13 -- Indirect heat exchanger 20 - Accompanying water 21 -- Pretreated water 22 "- Filtrate water 23 "- Pretreated waste water 24 "- Membrane-concentrated water 25 " Evaporation-concentrated supply water 26 "- Condensed water 27 -- Evaporation-concentrated water 28 "- Cooling water 30 "- Air 30a "- Compressed air 31 "- Waste gas 32 -- Steam 32A -- First steam supply system 33 "- Fuel gas 34 -" Steam 34A " Second steam supply system 35 -- C0 2 -containing gas 40 "- Mixed water tank 33 H \masIntevoven\NRPotbl\DCC\MAS\6 46761l.doc-15/05/2014 -34 41 ''' Chemicals injection equipment 42 "' Heating tank (heater) 43 '" Microscopic bubble generator 100 Concentration plant (concentration device) 5 200 Gas turbine generator 210 Heat resource 210A Heat resource supply system 300 Concentration device 10 Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of 15 any other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment 20 or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.