Plant startup method

Abstract

To provide a starting method for a plant including a gas turbine cogeneration system using off-gas generated in a process in which bio liquid fuel is generated from biomass as fuel.SOLUTION: A starting method for a plant includes: a cogeneration system start step of starting a gas turbine cogeneration system; a fuel refining plant start step of starting supply of boiler steam to a fuel refining plant after execution of the cogeneration system start step; a bio liquid fuel generation plant start step of starting a gasification device and a bio liquid fuel generation device after the execution of the fuel refining plant start step; and a mixed gas fuel supply step of starting supply of mixed gas fuel including fuel gas, first off-gas generated in the fuel refining plant and second off-gas that is generated in the bio liquid fuel generation device and has a heating value per unit mass smaller than that of the fuel gas to the gas turbine after the execution of the bio liquid fuel generation plant start step.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to a method for starting up a plant including a gas turbine cogeneration system that uses at least off-gas as fuel.

Background Art

[0002] The gas turbine cogeneration system disclosed in Patent Document 1 incorporates a liquid fuel synthesis reaction vessel configured to produce liquid fuel from gasified gas obtained from solid fuel containing coal. The gas turbine in this document is driven using the off-gas generated in the liquid fuel synthesis reaction vessel as fuel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] To realize a carbon-neutral society, it is preferable that the solid fuel be biomass. However, when biomass is adopted as the solid fuel, the calorific value per unit mass of the off-gas obtained from the liquid fuel synthesis reaction vessel is generally small, and it is difficult to start up an existing gas turbine using the off-gas as a sole fuel, and it is also difficult to start up a plant including a gas turbine cogeneration system.

[0005] An object of the present disclosure is to provide a method for starting up a plant including a gas turbine cogeneration system that uses off-gas generated in the process of generating bio-liquid fuel from biomass as fuel.

Means for Solving the Problems

[0006] A method for starting up a plant according to at least one embodiment of the present disclosure is A gas turbine cogeneration system including a gas turbine, a heat recovery boiler, and a fuel gas supply line for supplying fuel gas to the gas turbine, A bio-liquid fuel production plant including a gasifier for producing bio-mass gas from biomass and a bio-liquid fuel production device for producing bio-liquid fuel from the bio-mass gas, A fuel purification plant for purifying a fuel such as fuel oil from the bio-liquid fuel produced by the bio-liquid fuel using the boiler steam discharged from the heat recovery boiler as a heat source A method for starting a plant comprising: A cogeneration system startup step of starting the gas turbine cogeneration system; After the execution of the cogeneration system startup step, a fuel purification plant startup step of starting the supply of the boiler steam to the fuel purification plant; After the execution of the fuel purification plant startup step, a bio-liquid fuel production plant startup step of starting the gasifier and the bio-liquid fuel production device; After the execution of the bio-liquid fuel production plant startup step, a mixed gas fuel supply step of starting to supply a mixed gas fuel including the fuel gas, a first off-gas generated in the fuel purification plant, and a second off-gas having a calorific value per unit mass smaller than that of the fuel gas and generated in the bio-liquid fuel production device to the gas turbine Comprising.

Effect of the Invention

[0007] According to the present disclosure, a method for starting a plant including a gas turbine cogeneration system using off-gas generated in the process of producing bio-liquid fuel from biomass as fuel can be provided.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely illustrative examples. For example, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only strictly represent such arrangements, but also represent states in which there are tolerances or relative displacements with angles or distances that provide the same function. For example, expressions representing that things such as "identical", "equal", and "homogeneous" are in an equal state not only strictly represent an equal state, but also represent states in which there are tolerances or differences that provide the same function. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent shapes such as a rectangular shape or a cylindrical shape in a geometrically strict sense, but also represent shapes including concavo-convex portions, chamfered portions, etc. within a range where the same effect can be obtained. On the other hand, the expressions "comprising", "including", or "having" a component are not exclusive expressions that exclude the existence of other components. Note that the same reference numerals may be given to the same configurations and the description may be omitted.

[0010] <1. Overview of Plant 1> FIG. 1 is a schematic diagram of a plant 1 according to an embodiment of the present disclosure. The plant 1 includes a gas turbine cogeneration system 10 including a gas turbine 9 and a heat recovery boiler 14, a fuel refining plant 100 for refining fuel from oil, and a bio-liquid fuel production plant 200 for producing bio-liquid fuel from biomass.

[0011] The gas turbine 9 undertakes the power generation function in the cogeneration system 10. The exhaust heat recovery boiler 14 is configured to generate steam using the exhaust gas 13 discharged from the gas turbine 9 as a heat source. At least a part of the boiler steam, which is the steam discharged from the exhaust heat recovery boiler 14, is supplied to the fuel purification plant 100 and the bio-liquid fuel production plant 200. As a more specific example, the boiler steam that has passed through the steam demand unit 11 arranged downstream of the exhaust heat recovery boiler 14 is supplied to both plants. The boiler steam is used as a heat source for purifying fuel in the fuel purification plant 100 and as a gasifying agent for obtaining biomass gas from biomass in the bio-liquid fuel production plant 200.

[0012] As a configuration for supplying the boiler steam to both plants, a boiler steam supply line 82 and a steam supply line 87 for the gasifying agent are provided. The boiler steam supply line 82 includes a boiler steam supply pipe 82A connected to the steam demand unit 11 and the fuel purification plant 100, and a boiler steam on-off valve 82B provided in the boiler steam supply pipe 82A. Further, the steam supply line 87 for the gasifying agent includes a steam supply pipe 87A for the gasifying agent connected to the boiler steam supply pipe 82A and the bio-liquid fuel production plant 200, and a steam on-off valve 87B for the gasifying agent provided in the steam supply pipe 87A for the gasifying agent. The position where the steam supply pipe 87A for the gasifying agent is connected to the boiler steam supply pipe 82A is between the steam demand unit 11 and the fuel purification plant 100, and the boiler steam extracted from the steam supply pipe 87A for the gasifying agent flows through the steam supply pipe 87A for the gasifying agent as a gasifying agent.

[0013] The fuel supplied to the combustor 3 of the gas turbine 9 includes at least one of fuel gas, the first off-gas generated in the fuel refining plant 100, or the second off-gas generated in the bio-liquid fuel production plant 200. The calorific value per unit mass of the fuel gas is relatively high, and in the startup operation of the gas turbine 9, only the fuel gas is supplied to the combustor 3. Also, after the completion of the startup operation, the fuel gas is mixed with at least one of the first off-gas or the second off-gas and supplied to the combustor 3. In the present embodiment, the mixing of the gases is carried out in the gas mixing device 8 that constitutes the gas turbine cogeneration system 10.

[0014] The fuel gas includes at least one of, for example, LNG or LPG. The fuel gas in this example is LPG (LPG; liquefied petroleum gas). In this case, LPG is refined as fuel gas in the fuel refining plant 100. Also, the calorific value per unit mass of the second off-gas is lower than that of the fuel gas. Further, in this example, the calorific value per unit mass of the second off-gas is lower than that of the first off-gas. Specific examples of the first off-gas and the second off-gas will be described later.

[0015] Hereinafter, the configurations of the fuel refining plant 100, the bio-liquid fuel production plant 200, the fuel supply system 60 for supplying fuel for the gas turbine, and the gas turbine cogeneration system 10 will be described in order. In the following description, the gas turbine cogeneration system 10 may be abbreviated as the "cogeneration system 10".

[0016] <2. Fuel Refining Plant 100> FIG. 2 is a schematic diagram of a fuel refining plant 100 according to an embodiment of the present disclosure. The fuel refining plant 100 includes a distillation refining apparatus 103 and a fuel storage facility 105. The distillation refining apparatus 103 is configured to refine fuel from oil using boiler steam supplied through a boiler steam supply pipe 82A as a heat source. The oil may be crude oil or may be crude oil of bio-liquid fuel. In the present embodiment, the crude oil supplied from the crude oil supply facility 109 or the bio-liquid fuel (crude oil) supplied from the bio-liquid fuel production plant 200 is selectively supplied to the distillation refining apparatus 103. The fuel as a product to be refined is, for example, bio-jet fuel, naphtha, or LPG. The refined fuel may be used as fuel for the combustor 3 or may be used as fuel for other equipment.

[0017] Although detailed illustration is omitted, the distillation refining apparatus 103 has a heating furnace for heating oil and a distillation column for distilling the oil discharged from the heating furnace to extract fuel. The boiler steam supply pipe 82A in this example is connected to the distillation column, and the distillation column distills the oil using boiler steam as a heat source. The fuel refined through distillation is supplied to the fuel storage facility 105.

[0018] The fuel refining plant 100 further includes a first off-gas discharge pipe 107 through which the first off-gas generated in the distillation column of the distillation refining apparatus 103 flows, a first off-gas supply device 170 configured to receive the first off-gas flowing through the first off-gas discharge pipe 107, and a first off-gas supply line 110 for supplying the first off-gas from the first off-gas supply device 170 to the gas mixing device 8.

[0019] The first off-gas supply device 170 is configured to increase the pressure of the first off-gas and then flow the first off-gas into the first off-gas supply line 110. The first off-gas supply line 110 includes a first off-gas supply pipe 115 connected to the first off-gas supply device 170 and the gas mixing device 8, and a first off-gas on-off valve 117 provided in the first off-gas supply pipe 115. The first off-gas supply pipe 115 guides the first off-gas discharged from the first off-gas supply device 170 to the gas mixing device 8. Then, the gas containing the first off-gas generated by mixing in the gas mixing device 8 is supplied to the combustor 3 of the gas turbine 9 (details will be described later). Therefore, both the first off-gas supply device 170 and the first off-gas supply line 110 are responsible for the function of supplying the first off-gas to the combustor 3. Note that the first off-gas contains at least one of, for example, methane gas, ethane gas, butane gas, or propane gas.

[0020] <3. Bio-liquid fuel production plant 200> FIG. 3 is a schematic diagram of a bio-liquid fuel production plant 200 according to an embodiment of the present disclosure. The bio-liquid fuel production plant 200 includes a steam supply device 201 configured to receive boiler steam supplied by a gasifying agent steam supply pipe 87A, a biomass supply device 203 that is a supply source of biomass, an oxygen gas supply device 205 for supplying oxygen gas, and a gasification device 233 for generating biomass gas from biomass.

[0021] The steam supply device 201 supplies steam as a gasifying agent to the gasification device 233 via the steam supply pipe 221. The steam supplied by the steam supply device 201 includes boiler steam supplied by the gasifying agent steam supply line 87. The biomass supply device 203 performs drying treatment and pulverization on biomass, which may be, for example, woody biomass. The biomass discharged from the biomass supply device 203 is supplied to the gasification device 233 via the biomass supply pipe 223. The oxygen gas discharged from the oxygen gas supply device 205 is supplied to the gasification device 233 via the oxygen gas supply pipe 235. The steam supply pipe 221, the biomass supply pipe 223, and the oxygen gas supply pipe 235 are respectively provided with a steam on-off valve 221A, a biomass on-off valve 223A, and an oxygen gas on-off valve 235A.

[0022] The oxygen gas flowing into the oxygen gas supply device 205 of the present embodiment includes the oxygen gas generated by the oxygen gas generation device 209 and the oxygen gas generated by the electrolysis device 61 (see FIG. 6). The oxygen gas generation device 209 is configured to extract oxygen gas from the atmosphere by pressure swing adsorption (PSA; Pressure Swing Adsorption). Although the details of the electrolysis device 61 will be described later, the oxygen gas generated by the electrolysis device 61 is supplied to the oxygen gas generation device 209 by the oxygen gas supply line 64.

[0023] The gasification device 233 is configured to generate biomass gas from biomass using boiler steam and oxygen gas as gasifying agents. More specifically, the gasification device 233 has a gas furnace that employs an entrained-flow biomass gasification process. Boiler steam and oxygen gas flow in near the bottom of the gas furnace, and biomass flows in above the bottom. The boiler steam and oxygen gas mixed in the gas furnace rise and strike the biomass, generating biomass gas. The biomass gas contains at least one of hydrogen, carbon monoxide, or carbon dioxide.

[0024] As shown in FIG. 3, the bio-liquid fuel production plant 200 further includes a biomass gas discharge pipe 280 through which the biomass gas discharged from the gasifier 233 flows, a biomass gas on-off valve 280A provided in the biomass gas discharge pipe 280, and a bio-liquid fuel production device 290 configured to produce bio-liquid fuel from the biomass gas flowing in through the biomass gas discharge pipe 280. The bio-liquid fuel production device 290 of the present embodiment employs the Fischer-Tropsch process. More specifically, the bio-liquid fuel production device 290 is configured to produce bio-liquid fuel from biomass gas while using iron and cobalt as catalysts. The bio-liquid fuel in this example is crude oil, which is a raw material for bio-jet fuel.

[0025] The bio-liquid fuel production plant 200 according to some embodiments further includes a bio-liquid fuel supply line 291 for supplying the bio-liquid fuel discharged from the bio-liquid fuel production device 290 to the fuel purification plant 100 as oil (crude oil) to be purified. The bio-liquid fuel supply line 291 includes a bio-liquid fuel supply pipe 291A connected to the bio-liquid fuel production device 290 and the heating furnace of the distillation purification device 103 (see FIG. 2), and a bio-liquid fuel on-off valve 291B provided in the bio-liquid fuel supply pipe 291A.

[0026] In the above-described bio-liquid fuel production device 290, second off-gas is generated together with the bio-liquid fuel. The bio-liquid fuel production plant 200 of this example further includes a second off-gas discharge pipe 237 through which the second off-gas generated in the bio-liquid fuel production device 290 flows, a second off-gas supply device 270 that receives the second off-gas flowing through the second off-gas discharge pipe 237, and a second off-gas supply line 220 for supplying the second off-gas from the second off-gas supply device 270 to the gas mixing device 8.

[0027] The second off-gas supply device 270 is configured to discharge the second off-gas into the second off-gas supply line 220 after increasing the pressure of the second off-gas. The second off-gas supply line 220 includes a second off-gas supply pipe 225 connected to the second off-gas supply device 270 and the gas mixing device 8, and a second off-gas on-off valve 227 provided in the second off-gas supply pipe 225. The second off-gas supply pipe 225 guides the second off-gas discharged from the second off-gas supply device 270 to the gas mixing device 8. Then, the gas containing the second off-gas generated by mixing in the gas mixing device 8 is supplied to the combustor 3 of the gas turbine 9 (details will be described later). Therefore, both the second off-gas supply device 270 and the second off-gas supply line 220 are responsible for the function of supplying the second off-gas to the combustor 3. Note that the second off-gas contains at least one of, for example, methane gas, carbon monoxide, carbon dioxide, hydrogen gas, or nitrogen gas.

[0028] <4. Fuel Supply System 60> FIG. 4 is a schematic diagram of a fuel supply system 60 according to an embodiment of the present disclosure. The fuel supply system 60 is configured to supply fuel to the combustor 3 of the gas turbine 9. The components of the fuel supply system 60 are also components of any one of a fuel purification plant 100, a bio-liquid fuel production plant 200, or a cogeneration system 10.

[0029] A fuel supply system 60 according to an embodiment of the present disclosure includes a first off-gas supply device 170, a first off-gas supply line 110, a second off-gas supply device 270, and a second off-gas supply line 220. The details of these components are as described above. And the fuel supply system 60 further includes a fuel gas supply source 62, a fuel gas supply line 70 for supplying fuel gas from the fuel gas supply source 62 to the combustor 3, a gas mixing device 8 for mixing the fuel gas, the first off-gas, and the second off-gas, and a mixed gas fuel supply line 4 for supplying the mixed gas fuel generated by the gas mixing device 8 to the combustor 3.

[0030] The fuel gas supply source 62 in this example is a tank storing fuel gas and is installed in the plant 1. The fuel gas supply source 62 in other examples may be a large tank truck parked near the plant 1. In this case, the fuel gas supply source 62 may not be a component of the fuel supply system 60.

[0031] The fuel gas supply line 70 includes a startup fuel gas supply line 72 for supplying fuel gas as startup fuel to the combustor 3, and a mixing fuel gas supply line 77 provided in parallel with the startup fuel gas supply line 72 and for supplying fuel gas to the gas mixing device 8. The startup fuel gas supply line 72 has a startup fuel gas supply pipe 72A connected to the fuel gas supply source 62 and the combustor 3, and a startup fuel gas on-off valve 72B provided in the startup fuel gas supply pipe 72A. The mixing fuel gas supply line 77 has a mixing fuel gas supply pipe 77A connected to the startup fuel gas supply pipe 72A and the gas mixing device 8, and a mixing fuel gas on-off valve 77B provided in the mixing fuel gas supply pipe 77A. The position where the mixing fuel gas supply pipe 77A is connected to the startup fuel gas supply pipe 72A is between the fuel gas supply source 62 and the startup fuel gas on-off valve 72B. The mixed gas fuel supply line 4 has a mixed gas fuel supply pipe 4A connected to the gas mixing device 8 and the combustor 3, and a mixed gas fuel on-off valve 4B provided in the mixed gas fuel supply pipe 4A.

[0032] The outline of the operation of the fuel supply system 60 for supplying fuel is as follows. When the cogeneration system 10 is started up, only the fuel gas from the fuel gas supply source 62 is supplied to the combustor 3 exclusively. More specifically, with the startup of the cogeneration system 10, the startup fuel gas on-off valve 72B is opened, and the mixing fuel gas on-off valve 77B, the first off-gas on-off valve 117, the second off-gas on-off valve 227, and the mixed gas fuel on-off valve 4B are all closed. Thereby, fuel gas is supplied to the combustor 3 exclusively through the startup fuel gas supply line 72. After the cogeneration system 10 is started, the startup fuel gas on-off valve 72B is closed. Around this closing timing, the mixing fuel gas on-off valve 77B, the first off-gas on-off valve 117, the second off-gas on-off valve 227, and the mixed gas fuel on-off valve 4B are all opened. The gas mixing device 8 generates mixed gas fuel by mixing fuel gas, the first off-gas, and the second off-gas. The mixed gas fuel containing fuel gas, the first off-gas, and the second off-gas is supplied to the combustor 3 via the mixed gas fuel supply line 4.

[0033] According to the above configuration, the second off-gas generated in the process of generating bio-liquid fuel from biomass can be used as fuel for the combustor 3 together with the fuel gas and the first off-gas. Thereby, since the calorific value obtained by combustion in the combustor 3 can be ensured, the combustion gas 12 (see FIG. 1) supplied to the turbine 2 can be heated to a high temperature, and the gas turbine 9 can be driven. Therefore, a cogeneration system 10 that drives using the second off-gas obtained in the process of generating bio-liquid fuel from biomass as fuel is realized. Further, since the second off-gas is used as fuel, the consumption of the fuel gas having a large calorific value per unit mass can be reduced, which can contribute to carbon neutrality. Note that the bio-liquid fuel generated in the bio-liquid fuel production plant 200 may not be supplied to the fuel purification plant 100. That is, the bio-liquid fuel production plant 200 may not include the bio-liquid fuel supply line 291. Even in this case, the above advantages can be obtained. Further, before the operation of discharging the above-described mixed gas fuel, the gas mixing device 8 may perform an operation of discharging the first mixed gas fuel containing fuel gas and the first off-gas, or an operation of discharging the second mixed gas fuel containing fuel gas and the second off-gas. Details will be described later in conjunction with the startup method of the cogeneration system 10.

[0034] Moreover, according to the configuration in which the gas mixing device 8 and the mixed gas fuel supply line 4 are provided, the mixed gas fuel generated by mixing the fuel gas, the first off-gas, and the second off-gas is supplied to the combustor 3. Thereby, the influence of the relatively small calorific value of the second off-gas can be reduced, and it is possible to avoid the calorific value obtained in the combustor 3 from being insufficient. Further, even in the existing combustor 3 where it is difficult to increase the temperature of the exhaust gas 13 (see FIG. 1) described later even when the second off-gas is supplied alone, it becomes possible to use the second off-gas as fuel, contributing to carbon neutrality.

[0035] According to the above fuel supply system 60, the mixed gas fuel supply line 4 can use the second off-gas generated in the bio-liquid fuel production plant 200 as fuel for the combustor 3 together with the fuel gas and the first off-gas. Thereby, since the calorific value obtained by combustion in the combustor 3 can be ensured, the combustion gas 12 (see FIG. 1) to be supplied to the turbine 2 can be heated to a high temperature, and the gas turbine 9 can be driven. Therefore, a fuel supply system 60 is realized that drives the gas turbine 9 using the second off-gas obtained in the process of producing bio-liquid fuel from biomass as fuel. Note that, in order to realize such a fuel supply system 60, it is not necessary to supply boiler steam to each of the fuel purification plant 100 and the bio-liquid fuel production plant 200. Also, the bio-liquid fuel produced in the bio-liquid fuel production plant 200 does not have to be supplied to the fuel purification plant 100. That is, the bio-liquid fuel production plant 200 does not have to include the bio-liquid fuel supply line 291. Even in this case, the above advantages can be obtained.

[0036] Moreover, according to the configuration in which the mixing fuel gas supply line 77 is provided in parallel with the starting fuel gas supply line 72, the starting fuel gas supply line 72 and the mixed gas fuel supply line 4 can utilize a common fuel gas supply source 62, so the configuration of the fuel supply system 60 can be simplified.

[0037] Moreover, according to the configuration in which the bio-liquid fuel production plant 200 includes a bio-liquid fuel supply line 291 for supplying bio-liquid fuel to the fuel purification plant 100, it becomes possible to purify fuels such as bio-jet fuel from the bio-liquid fuel.

[0038] <5. Gas Turbine Cogeneration System 10> Referring to FIGS. 1 and 5, the gas turbine cogeneration system 10 will be described. FIG. 5 is a schematic diagram of the water recovery system 40 according to an embodiment of the present disclosure.

[0039] <5-1. Overview of Cogeneration System 10> The cogeneration system 10 shown in FIG. 1 includes a gas turbine 9 and an exhaust heat recovery boiler 14. The gas turbine 9 includes a compressor 16 for generating compressed air 7 from the compressor inlet air 6, a combustor 3 for burning the fuel supplied by the fuel supply system 60 and heating the compressed air 7 to a high temperature to generate combustion gas 12, a turbine 2 for rotating using the combustion gas 12 discharged from the combustor 3 as a driving source, and a generator 5 connected to the turbine 2. The combustor 3 of the present embodiment is a diffusion type combustor. The fuel supplied by the combustor 3 is supplied by the aforementioned fuel supply system 60.

[0040] The exhaust heat recovery boiler 14 is configured to generate steam from boiler feed water using the exhaust gas 13, which is the combustion gas 12 discharged from the turbine 2, as a heat source. Here, the boiler feed water is the water supplied to the exhaust heat recovery boiler 14. The cogeneration system 10 includes a steam supply pipe 21 for supplying the boiler steam discharged from the exhaust heat recovery boiler 14 to the steam demand unit 11. The steam demand unit 11 in this example is a steam turbine. The steam demand unit 11 according to other examples may be a steam turbine of a combined power generation plant or an industrial process device, etc.

[0041] Although not an essential component of the present disclosure, the cogeneration system 10 includes a steam extraction pipe 130 for supplying boiler steam extracted from the steam supply pipe 21 to the combustor 3. The steam extraction pipe 130 illustrated in the figure is configured to supply boiler steam to the head end (not shown) side in the combustor 3. The boiler steam supplied to the head end side suppresses the generation of nitrogen participation substances in the combustor 3 by lowering the temperature of the flame zone of the combustor 3.

[0042] Although not an essential component of the present disclosure, the cogeneration system 10 includes a water recovery system 40 for recovering moisture contained in the exhaust gas 13 discharged from the exhaust heat recovery boiler 14, a makeup water tank 17 for storing the recovered water containing the moisture recovered by the water recovery system 40 as boiler feed water, a water supply line 15 for supplying makeup water to the makeup water tank 17, a water supply line 19 connected to the makeup water tank 17 and the exhaust heat recovery boiler 14, and a water supply pump 18 provided in the water supply line 19. Details of the configuration of the water recovery system 40 will be described later. When the water supply pump 18 is driven, the boiler feed water stored in the makeup water tank 17 flows through the water supply line 19 and is supplied to the exhaust heat recovery boiler 14. It is preferable that the temperature of the boiler feed water supplied to the exhaust heat recovery boiler 14 is high. This is because the amount of heat required for the exhaust heat recovery boiler 14 to generate steam is reduced, and the efficiency of the cogeneration system 10 is improved.

[0043] Although not an essential component of the present disclosure, the cogeneration system 10 includes an exhaust gas supply line 57 which is a supply line of the exhaust gas 13 from the exhaust heat recovery boiler 14 to the water recovery system 40, an exhaust line 29 branched from the exhaust gas supply line 57, and an exhaust damper 31 provided in the exhaust line 29. The exhaust gas 13 flowing through the exhaust line 29 is discharged to the outside from the exhaust tower 30. In one embodiment of the present disclosure, when the exhaust gas 13 is supplied from the cogeneration system 10 to the water recovery system 40, the exhaust damper 31 is closed and no exhaust gas 13 flows through the exhaust line 29.

[0044] <5-2. Water recovery system 40> The outline of the water recovery system 40 shown in Fig. 5 is as follows. The water recovery device 33, which is a component of the water recovery system 40, is configured to recover the moisture in the exhaust gas 13 as recovered water by bringing the exhaust gas 13 guided by the exhaust gas supply line 57 into gas-liquid contact with the chilled water. As a more detailed example, the water recovery device 33 includes a heat exchange container 135 into which the exhaust gas 13 and the chilled water flow, a water sprinkling device 34 for sprinkling the chilled water inside the heat exchange container 135, and a packing 35 located below the water sprinkling device 34 inside the heat exchange container 135. When the water recovery damper 59 provided in the exhaust gas supply line 57 is opened, the exhaust gas 13 flows into the heat exchange container 135 from the exhaust gas supply line 57. The chilled water sprinkled by the water sprinkling device 34 adheres to the packing 35 and exchanges heat with the exhaust gas 13 flowing into the heat exchange container 135. As a result, the moisture in the exhaust gas 13 condenses. The recovered water containing the condensed moisture and the chilled water that has completed heat exchange drops and accumulates in the water storage tank 136 that constitutes the lower part of the heat exchange container 135.

[0045] The configuration of the water recovery system 40 will be described in detail. The water recovery system 40 further includes a recovered water cooling device 36 for cooling the recovered water discharged from the water storage tank 136 of the water recovery device 33, a recovered water discharge line 39 for guiding the recovered water discharged from the water storage tank 136 of the water recovery device 33 to the recovered water cooling device 36, and a recovered water supply line 42 for guiding the cooled recovered water discharged from the recovered water cooling device 36 to the heat exchange container 135 as chilled water. The recovered water cooling device 36 in this example is configured to cool the recovered water with cooling water that may be, for example, seawater. A cooling water supply pump 55 is provided in the cooling water supply line 41 for supplying the cooling water to the recovered water cooling device 36.

[0046] The water recovery system 40 further includes a water supply line 43 for guiding the recovered water to the makeup water tank 17, and the water supply line 43 includes a high-temperature water supply line 44 and a low-temperature water supply line 47. The high-temperature water supply line 44 is connected to the recovered water discharge line 39 and is configured to guide the recovered water taken out from the recovered water discharge line 39 to the makeup water tank 17. Since the recovered water taken out from the recovered water discharge line 39 has the heat recovered from the exhaust gas 13, it has a relatively high temperature. The low-temperature water supply line 47 is connected to the recovered water supply line 42 and is configured to guide the recovered water taken out from the recovered water supply line 42 to the makeup water tank 17. Since the recovered water taken out from the recovered water supply line 42 has been subjected to a cooling process by the recovered water cooling device 36, it has a relatively low temperature.

[0047] A water treatment device 46, which is a component of the water recovery system 40, is provided in the low-temperature water supply line 47. The water treatment device 46 is configured to perform a process of removing impurities such as sulfur from the recovered water flowing through the low-temperature water supply line 47. The impurities are generated during the combustion in the combustor 3 (see FIG. 1) and may be mixed into the exhaust gas 13. At least a part of these impurities is dissolved in the recovered water by the heat exchange between the exhaust gas 13 and the refrigerant water in the water recovery device 33. By removing the impurities contained in the recovered water by the water treatment device 46, it is suppressed that the boiler feed water stored in the makeup water tank 17 contains impurities. Generally, the lower the temperature of the water to be treated, the higher the treatment capacity of the water treatment device 46 for removing impurities. When the temperature of the recovered water is high, the ion exchange resin 146 constituting the water treatment device 46 may be damaged, and there is a risk that the treatment capacity for removing impurities may decrease.

[0048] A high-temperature feed water valve 48 is provided in the high-temperature feed water line 44, and a low-temperature feed water valve 45 is provided in the low-temperature feed water line 47. When a fuel gas, which may be LPG classified as clean energy, is supplied as a startup fuel to the combustor 3 in the cogeneration system 10, or when, after the startup of the cogeneration system 10, the second off-gas generated in the bio-liquid fuel production plant 200 is supplied to the combustor 3 together with the fuel gas, the amount of impurities mixed into the exhaust gas 13 is less than the allowable value. In this case, the high-temperature feed water valve 48 is opened, and high-temperature recovered water that does not require impurity removal treatment flows into the makeup water tank 17 via the high-temperature feed water line 44 (at this time, the low-temperature feed water valve 45 is closed). Since the temperature of the boiler feed water supplied from the makeup water tank 17 to the exhaust heat recovery boiler 14 can be increased, the efficiency of the cogeneration system 10 is improved.

[0049] On the other hand, after the startup of the cogeneration system 10, when the first off-gas generated in the fuel purification plant 100 is supplied to the combustor 3 together with the fuel gas, the amount of impurities mixed into the exhaust gas 13 is equal to or greater than the allowable value and less than the upper allowable limit value. In this case, the high-temperature feed water valve 48 is closed, the low-temperature feed water valve 45 is opened, and low-temperature recovered water that requires impurity removal treatment flows into the makeup water tank 17 via the water treatment device 46 provided in the low-temperature feed water line 47. Thus, it is possible to avoid impurities from adhering to the devices constituting the cogeneration system 10, such as the feed water line 19 and the exhaust heat recovery boiler 14, and suppress the deterioration of the cogeneration system 10.

[0050] In addition, when the amount of impurities contained in the exhaust gas 13 is equal to or greater than the upper allowable limit value, the water recovery damper 59 is closed, and the exhaust damper 31 (see FIG. 1) is opened. As a result, the exhaust gas 13 is discharged from the exhaust tower 30 without being supplied to the water recovery system 40.

[0051] According to the above configuration, while the fuel gas as the starting fuel is exclusively supplied to the combustor 3, or while the second off-gas is supplied to the combustor 3 together with the fuel gas, the amount of impurities in the exhaust gas 13 flowing into the water recovery device 33 is less than the allowable value, so that the supply of recovered water by the high-temperature feed water line 44 becomes possible. Thereby, the boiler feed water supplied to the exhaust heat recovery boiler 14 can be heated to a high temperature, and the operating efficiency of the cogeneration system 10 can be improved. On the other hand, while the mixed gas fuel containing the first off-gas is supplied to the combustor 3, the amount of impurities in the exhaust gas 13 is equal to or greater than the allowable value and less than the allowable upper limit value. At this time, instead of the high-temperature feed water line 44, the low-temperature feed water line 47 supplies the recovered water, and in this supply process, the water treatment device 46 can remove the impurities contained in the recovered water. Thereby, corrosion of the equipment caused by the adhesion of impurities to the equipment constituting the cogeneration system 10 can be avoided. Thus, in the water recovery system 40 of this example, it is possible to switch the feed water line 43 of the recovered water sent to the makeup water tank 17 according to the amount of impurities contained in the fuel supplied to the combustor 3.

[0052] <5-3. Electrolysis device 61> FIG. 6 is a schematic diagram showing supply lines of oxygen gas and hydrogen gas generated by the electrolysis device 61 according to an embodiment of the present disclosure.

[0053] Although not an essential component of the present disclosure, the cogeneration system 10 may further include a pumping line 49 for pumping the boiler feed water flowing through the feed water line 19, a pumping on-off valve 50 provided in the pumping line 49, and an electrolysis device 61 connected to the pumping line 49. The boiler feed water pumped by the pumping line 49 (hereinafter sometimes referred to as "industrial water") includes the recovered water discharged from the water recovery device 33 (see FIG. 5) and the makeup water supplied by the feed water line 15.

[0054] The electrolysis device 61 is configured to perform an electrolysis process on the industrial water flowing through the pumping line 49. By performing the electrolysis process, oxygen gas and hydrogen gas are generated from the industrial water. The oxygen gas generated by the electrolysis device 61 is supplied to the oxygen gas supply device 205 through the oxygen gas supply line 64 as a gasifying agent for use in the gasifier 233 of the bio-liquid fuel production plant 200. The oxygen gas supply line 64, which is a component of the cogeneration system 10, includes an oxygen gas supply pipe 64A connected to the electrolysis device 61 and the oxygen gas supply device 205, and an oxygen gas on-off valve 64B provided in the oxygen gas supply pipe 64A. In the oxygen gas supply pipe 64A, the oxygen gas generated by the electrolysis device 61 is configured to be joined by the oxygen gas generated by the above-described oxygen gas generation device 209. More specifically, the oxygen gas generation device 209 and the oxygen gas supply pipe 64A are connected by an oxygen gas discharge pipe 207. The position where the oxygen gas discharge pipe 207 is connected to the oxygen gas supply pipe 64A is between the oxygen gas on-off valve 64B and the oxygen gas supply device 205.

[0055] The hydrogen gas generated by the electrolysis device 61 is supplied to the bio-liquid fuel production device 290 through the hydrogen gas supply line 68. The hydrogen gas supply line 68, which is a component of the cogeneration system 10, includes a hydrogen gas supply pipe 68A connected to the electrolysis device 61 and the biomass gas discharge pipe 280, and a hydrogen gas on-off valve 68B provided in the hydrogen gas supply pipe 68A. The hydrogen gas flowing through the hydrogen gas supply pipe 68A mixes with the biomass gas discharged from the gasifier 233 and is supplied to the bio-liquid fuel production device 290.

[0056] According to the above configuration, the oxygen gas obtained by using the recovered water recovered by the water recovery device 33 can be used as a gasifying agent for the gasifier 233. Thereby, by utilizing the moisture contained in the exhaust gas 13, a sufficient amount of gasifying agent can be supplied to the gasifier 233. Further, the hydrogen gas obtained by using the recovered water recovered by the water recovery device 33 can be used for the production of bio-liquid fuel. Thereby, by utilizing the moisture contained in the exhaust gas 13, a sufficient amount of hydrogen gas can be supplied to the bio-liquid fuel. Furthermore, in the above embodiment, the recovered water is utilized not only as a raw material for the bio-liquid fuel but also as a raw material for the first off-gas that becomes the fuel of the combustor 3. Therefore, it becomes possible to utilize the moisture mixed in the exhaust gas 13 of the cogeneration system 10 without waste.

[0057] <6. Controller 90> The plant 1 further includes a controller 90 (see FIGS. 1 to 5). The controller 90 is configured by a computer and includes a processor, a memory (storage medium), and an external communication interface. The processor is a CPU, GPU, MPU, DSP, or a combination thereof. The processor according to other embodiments may be realized by an integrated circuit such as a PLD, ASIC, FPGA, or MCU. The memory is configured to temporarily or non-temporarily store various data and is realized by, for example, at least one of RAM, ROM, or flash memory. According to the instructions of the program loaded into the memory, the processor executes various control processes. Further, the controller 90 may be a DCS board that constitutes one of a plurality of control panels of the plant 1.

[0058] The controller 90 sends signals (control signals) to various devices constituting the plant 1. The various devices that make up Plant 1 include on-off valves. By the controller 90 sending a signal (control signal) to the on-off valve, the on-off valve switches between the open state and the closed state. Here, the on-off valves include the mixed gas fuel on-off valve 4B, the low-temperature feed water on-off valve 45, the high-temperature feed water on-off valve 48, the pumping on-off valve 50, the oxygen gas on-off valve 64B, the hydrogen gas on-off valve 68B, the starting fuel gas on-off valve 72B, the mixing fuel gas on-off valve 77B, the boiler steam on-off valve 82B, the steam for gasifying agent on-off valve 87B, the first off-gas on-off valve 117, the steam on-off valve 221A, the biomass on-off valve 223A, the second off-gas on-off valve 227, the oxygen gas on-off valve 235A, the biomass gas on-off valve 280A, and the bio-liquid fuel on-off valve 291B. In addition, the various devices that make up Plant 1 include dampers. By the controller 90 sending a signal (control signal) to the damper, the damper switches between the open state and the closed state. Here, the dampers include the exhaust damper 31 and the water recovery damper 59.

[0059] Furthermore, the devices that make up Plant 1 include various pumps such as the feed water pump 18, the water recovery pump 38, and the cooling water supply pump 55, various devices and various facilities that make up the bio-liquid fuel production plant 200, and various devices and various facilities that make up the fuel purification plant 100. These various pumps, various devices, and various facilities are controlled by the controller 90.

[0060] <7. Startup Method of Plant 1> Referring to FIGS. 7 to 17, the startup method of Plant 1 according to the first embodiment and the startup method of Plant 1 according to the second embodiment will be described in order. The startup method of Plant 1 is executed by the controller 90 sending a signal (control) to the various devices that make up Plant 1. In the following, the description of the transmission and reception of signals executed between the controller 90 and the various devices will be omitted, and the startup method will be described. Also, in the following description, "step" may be abbreviated as "S". Note that the startup method of Plant 1 includes the startup method of the gas turbine cogeneration system 10. Before starting up Plant 1, all the on-off valves and dampers that make up Plant 1 are closed.

[0061] <7-1. Startup method according to the first embodiment> FIG. 7 is a flowchart showing a startup method of the plant 1 according to the first embodiment. FIG. 8 is a flowchart showing the continuation of the startup method of the plant 1. FIGS. 9 to 15 are schematic diagrams showing the process of the startup method of the plant 1. In each drawing, the diagram drawn by a thick line indicates that the supply target or the discharge target is flowing (the same applies to FIG. 17). Here, the supply target or the discharge target is a gas such as exhaust gas 13, boiler steam, fuel gas, hydrogen gas, or oxygen gas, a liquid such as bio-liquid fuel, crude oil, or boiler feed water, or a solid such as biomass.

[0062] First, as shown in FIGS. 7, 9, and 10, a cogeneration system startup step (S1) for starting the cogeneration system 10 is executed. In S1, the rotational drive of the gas turbine 9 is started by a startup device (not shown), and the startup fuel gas on-off valve 72B is opened, so that the startup fuel gas supply line 72 supplies only fuel gas as startup fuel to the combustor 3. Exclusive combustion of the fuel gas occurs in the combustion chamber of the combustor 3. Further in S1, the water recovery damper 59 is opened, and the water recovery system 40 is started by driving the water recovery pump 38 and the cooling water supply pump 55. The water recovery device 33 starts recovering moisture from the exhaust gas 13. Further, the high-temperature feed water on-off valve 48 of the water recovery system 40 is opened, and the supply of high-temperature recovered water from the high-temperature feed water line 44 to the makeup water tank 17 is started. At this time, the supply of makeup water from the feed water line 15 to the makeup water tank 17 is also started. Also, by driving the feed water pump 18, the feed water line 19 supplies boiler feed water to the waste heat recovery boiler 14.

[0063] Next, as shown in FIGS. 7 and 11, a fuel refining plant startup step (S3) is executed. In S3, crude oil is supplied from the crude oil supply facility 109 to the distillation refining apparatus 103, and the distillation refining apparatus 103 starts operating. At this time, the boiler steam on-off valve 82B is opened, and the boiler steam supply line 82 starts supplying boiler steam to the distillation refining apparatus 103. The distillation refining apparatus 103 purifies fuel from crude oil, which is an example of oil, using the boiler steam as a heat source.

[0064] Next, as shown in FIGS. 7 and 12, a mixed fuel gas supply step (S5) is executed in which the mixed fuel gas supply line 77 supplies fuel gas to the gas mixing apparatus 8 by opening the mixed fuel gas on-off valve 77B. When S5 is executed, the mixed gas fuel on-off valve 4B is also opened, and fuel gas is supplied from the gas mixing apparatus 8 to the combustor 3. Next, a starting fuel supply stop step (S7) is executed in which the starting fuel gas supply line 72 stops supplying fuel gas to the combustor 3 by closing the starting fuel gas on-off valve 72B. Thereafter, a first off-gas supply step (S9) is executed in which the first off-gas supply line 110 supplies the first off-gas to the gas mixing apparatus 8 by opening the first off-gas on-off valve 117. As a result, the gas mixing apparatus 8 generates a first mixed gas fuel by mixing the fuel gas and the first off-gas. The first mixed gas fuel is supplied to the combustor 3 via the mixed gas fuel supply line 4 (S11), and co-combustion of the fuel gas and the first off-gas occurs in the combustion chamber. Note that the first mixed gas fuel does not contain the second off-gas.

[0065] Next, as shown in FIGS. 7 and 13, a recovered water supply switching step (S13) is executed. In S13, the high-temperature feed water on-off valve 48 is closed, and the supply of high-temperature recovered water through the high-temperature feed water line 44 is stopped. At the same time, the low-temperature feed water on-off valve 45 is opened, and the supply of low-temperature recovered water through the low-temperature feed water line 47 is started. The low-temperature recovered water passes through the water treatment device 46 and is supplied to the makeup water tank 17. Thereby, even when impurities are contained in the recovered water due to the combustion of the first mixed gas fuel containing the first off-gas, the recovered water from which the impurities have been removed can be supplied to the makeup water tank 17. Note that S13 may be executed before S11. In this case, it is preferable that S13 is executed after S7 and before S11.

[0066] Next, as shown in FIGS. 7 and 14, a bio-liquid fuel production plant startup step (S15) is executed. In S15, the steam on-off valve 221A, the biomass on-off valve 223A, and the oxygen gas on-off valve 235A are opened, and the steam supply device 201, the biomass supply device 203, the oxygen gas supply device 205, and the gasification device 233 are started. At the same time, the biomass gas on-off valve 280A and the bio-liquid fuel on-off valve 291B are opened, and the bio-liquid fuel production device 290 is started. Thereby, the gasification device 233 generates biomass gas, and the bio-liquid fuel production device 290 generates bio-liquid fuel. The bio-liquid fuel production device 290 supplies bio-liquid fuel to the distillation purification device 103 of the fuel purification plant 100 through the bio-liquid fuel supply pipe 291A. At this time, the crude oil supply facility 109 may be stopped.

[0067] Note that at the time of execution of S15, neither the steam supply line 87 for the gasifying agent nor the oxygen gas supply line 64 has started operating yet. However, the amount of biomass supplied to the gasification device 233 at the startup stage of the bio-liquid fuel production plant 200 is small, and the amount of boiler steam and oxygen gas required in the gasification device 233 is small. Therefore, the startup of the gasification device 233 and the bio-liquid fuel production plant 200 is executed without problems, and a second off-gas is generated together with the bio-liquid fuel in the bio-liquid fuel production device 290.

[0068] Next, by opening the second off-gas on-off valve 227, a second off-gas supply step (S17) is executed in which the second off-gas supply line 220 supplies the second off-gas to the gas mixing device 8. The gas mixing device 8 generates a mixed gas fuel containing fuel gas, first off-gas, and second off-gas. As a result, a mixed gas fuel supply step (S21) is executed in which the mixed gas fuel is supplied to the combustor 3 via the mixed gas fuel supply line 4. Thereby, co-combustion of the fuel gas, first off-gas, and second off-gas occurs in the combustion chamber of the combustor 3. At this time, the amount of impurities in the exhaust gas 13 is equal to or greater than the allowable value and less than the allowable upper limit value, the low-temperature feed water line 47 continues to operate, and the high-temperature feed water line 44 does not operate.

[0069] Next, as shown in FIGS. 8 and 15, an electrolyzer startup step (S23) for starting the electrolyzer 61 is executed. In S23, the pumping on-off valve 50 is opened to supply industrial water to the electrolyzer 61, and the electrolyzer 61 is started. Thereby, oxygen gas and hydrogen gas are generated in the electrolyzer 61. Next, by opening the oxygen gas on-off valve 64B, an oxygen gas supply step (S25) is executed to start supplying oxygen gas from the oxygen gas supply line 64 to the oxygen gas supply device 205. Further, an oxygen gas generator startup step (S27) for starting the oxygen gas generator 209 is executed. The oxygen gas generated by the oxygen gas generator 209 flows into the oxygen gas supply line 64 and is supplied to the oxygen gas supply device 205. Next, by opening the steam on-off valve 87B for the gasifying agent (see FIG. 11), a gasifying agent supply step (S29) is executed to start supplying boiler steam as the gasifying agent from the steam supply line 87 for the gasifying agent to the steam supply device 201. The steam supply line 87 for the gasifying agent supplies boiler steam as the gasifying agent to the gasifier 233 via the steam supply device 201 and the steam supply pipe 221. Next, a hydrogen gas supply step (S31) is executed in which the hydrogen gas supply line 68 starts supplying hydrogen gas by opening the hydrogen gas on-off valve 68B. As a result, the amount of hydrogen gas flowing into the bio-liquid fuel generation device 290 increases, and the amount of bio-liquid fuel generated increases.

[0070] The advantages obtained by the startup method of the plant 1 according to the first embodiment described above will be described.

[0071] Since the fuel purification plant startup step (S3) is executed before the bio-liquid fuel generation plant startup step (S15), the fuel purification plant 100 can immediately accept the bio-liquid fuel generated by the bio-liquid fuel generation device 290. Therefore, the time from when the bio-liquid fuel is generated until the fuel is purified can be shortened. Also, in the mixed gas fuel supply step (S21) executed after the bio-liquid fuel generation plant startup step (S15), a mixed gas fuel containing fuel gas, first off-gas, and second off-gas can be supplied to the gas turbine 9, so the calorific value obtained by combustion in the combustor 3 can be ensured, and the high-temperature combustion gas 12 can be supplied to the turbine 2 to drive the gas turbine 9. Thus, a startup method for the plant 1 equipped with the cogeneration system 10 using the second off-gas obtained in the process of generating bio-liquid fuel as fuel is realized. Also, since the second off-gas is used as fuel, the consumption of fuel gas with a large calorific value per unit mass can be reduced, contributing to carbon neutrality.

[0072] Also, in the above startup method, after starting the gas turbine 9 by the cogeneration system startup step (S1) including the step of supplying startup fuel, the mixed gas fuel is supplied to the combustor 3 by the mixed gas fuel supply step (S21). As a result, the calorific value obtained by combustion in the combustor 3 can be ensured, so the high-temperature combustion gas 12 can be supplied to the turbine 2 to drive the gas turbine 9. Thus, a fuel supply method for the cogeneration system 10 that can supply the second off-gas obtained in the process of generating bio-liquid fuel from biomass as fuel to the cogeneration system 10 is realized.

[0073] In general, a large amount of boiler steam is required in the process of generating biomass gas from biomass. In this regard, in the above startup method, after the execution of the cogeneration system startup step (S1), a gasifying agent supply step (S25) is executed to start supplying boiler steam as a gasifying agent to the gasifier 233. According to the above configuration, it becomes possible to cover the steam as a gasifying agent required for generating biomass gas with the boiler steam discharged from the waste heat recovery boiler 14. Since the amount of boiler steam discharged from the waste heat recovery boiler 14 is very large, it is possible to avoid a shortage of steam as a gasifying agent in the gasifier 233, and it becomes possible to generate a sufficient amount of biomass gas.

[0074] In the above startup method, during the execution of the cogeneration system startup step (S1), the recovered water is supplied to the makeup water tank 17 by the high-temperature feed water line 44. Thereby, since the boiler feed water supplied to the waste heat recovery boiler 14 can be heated to a high temperature, the operating efficiency of the cogeneration system 10 can be improved.

[0075] In the above startup method, in the first mixed gas fuel supply step (S11), the first mixed gas fuel is supplied to the combustor 3 of the gas turbine 9. Thereby, the combustion environment in the combustor 3, such as the hydrogen gas concentration in the combustion chamber or the temperature of the combustion chamber, can be adjusted to the combustion environment for supplying the mixed gas fuel containing the second off-gas to the gas turbine 9. On the other hand, the first mixed gas fuel containing the first off-gas contains a certain amount of impurities, and there is a concern that the amount of impurities in the exhaust gas 13 may exceed the allowable value. In this regard, according to the above configuration, after the execution of the fuel purification plant startup step (S3), a recovered water supply switching step (S13) is executed. The low-temperature feed water line 47 supplies the recovered water instead of the high-temperature feed water line 44, and in this supply process, the water treatment device 46 can remove the impurities contained in the recovered water. Thereby, it is possible to avoid the corrosion of the equipment caused by the adhesion of impurities to the equipment constituting the cogeneration system 10.

[0076] Also, in the above startup method, by sequentially executing the electrolysis device startup step (S23) and the oxygen gas supply step (25), the oxygen gas obtained by using the recovered water recovered by the water recovery device 33 can be used as a gasifying agent in the gasification device 233. Thereby, by utilizing the moisture contained in the exhaust gas 13, a sufficient amount of gasifying agent can be supplied to the gasification device 233.

[0077] Also, in the above startup method, by sequentially executing the electrolysis device startup step (S23) and the hydrogen gas supply step (S31), the hydrogen gas obtained by using the recovered water recovered by the water recovery device 33 can be used for the production of bio-liquid fuel. Thereby, by utilizing the moisture contained in the exhaust gas 13, a sufficient amount of hydrogen gas can be supplied to the bio-liquid fuel.

[0078] Also, in the above startup method, by executing the oxygen gas generation device startup step (S27), it is possible to avoid a shortage of oxygen gas to be supplied to the gasification device 233.

[0079] Also, in the above startup method, before the execution of the first off-gas supply step (S9) and the second off-gas supply step (S17), the mixed fuel gas supply step (S5) is executed. In other words, before the start of the supply of the first off-gas by the first off-gas supply line 110 and before the start of the supply of the second off-gas by the second off-gas supply line 220, the mixed gas fuel supply line 4 is configured to start the supply of fuel gas to the gas mixing device 8. According to the above configuration, the mixing chamber of the gas mixing device 8 can be filled with a fuel gas having a relatively high calorific value per unit mass. Thereby, it is possible to avoid the calorific value per unit mass of the mixed gas fuel falling below the allowable lower limit value.

[0080] Also, in the above startup method, after the execution of the startup fuel supply step (S1) and before the execution of the mixed gas fuel supply step (S21), the first mixed gas fuel supply step (S11) is executed. In other words, the first off-gas supply line 110 is configured to start supplying the first off-gas before the start of the supply of the second off-gas by the second off-gas supply line 220. Further, the mixed gas fuel supply line 4 is configured to supply the first mixed gas fuel generated by the gas mixing device 8 to the combustor 3 before the start of the supply of the second off-gas by the second off-gas supply line 220. According to the above configuration, it becomes possible to optimize the combustion environment in the combustor 3, such as the hydrogen gas concentration in the combustion chamber or the temperature of the combustion chamber, for the combustion of the mixed gas fuel including the fuel gas, the first off-gas, and the second off-gas.

[0081] <7-2. Startup method according to the second embodiment> Referring to FIGS. 9, 10, 16, and 17, the startup method of the plant 1 according to the second embodiment will be described. FIG. 16 is a flowchart showing the startup method of the plant 1 according to the second embodiment. In the second embodiment, instead of S3, S9 to S17 shown in FIG. 7, S2, S8 to S14, S22 are executed. Also, among the steps shown in FIG. 16, those the same as in the first embodiment are given the same step numbers as in FIG. 7. Further, the startup method of the plant 1 after S23 according to the second embodiment of FIG. 16 is the same as the method shown by S23 to S31 (see FIG. 8) according to the first embodiment.

[0082] As shown in FIGS. 9, 10, and 16, first, the cogeneration system startup step (S1) is executed. The details of this step are as described in the startup method according to the first embodiment, and the supply of the high-temperature recovered water by the high-temperature water supply line 44 is also started in the same manner as in the first embodiment.

[0083] Next, as shown in FIGS. 16 and 17, a bio-liquid fuel production plant startup step (S2) is executed. In S2, the vapor on-off valve 87B for the gasifying agent is opened, and the supply of boiler vapor as the gasifying agent to the vapor supply device 201 is started. At the same time, the vapor supply device 201, the biomass supply device 203, the oxygen gas supply device 205, the gasification device 233, and the bio-liquid fuel production device 290 are started. Details are as described in S15 according to the first embodiment. At this time, although oxygen gas is not supplied from the oxygen gas supply line 64 to the oxygen gas supply device 205, since the amount of biomass supplied to the gasification device 233 during startup is small, the startup of the gasification device 233 and the bio-liquid fuel production plant 200 is executed without problems.

[0084] Next, in the same manner as in the first embodiment, a mixed fuel gas supply step (S5) and a startup fuel supply stop step (S7) are executed in order.

[0085] Next, a second off-gas supply step (S8) is executed by opening the second off-gas on-off valve 227 so that the second off-gas supply line 220 supplies the second off-gas to the gas mixing device 8. As a result, the gas mixing device 8 generates a second mixed gas fuel by mixing the fuel gas and the second off-gas. The second mixed gas fuel is supplied to the combustor 3 via the mixed gas fuel supply line 4 (S10), and co-combustion of the fuel gas and the second off-gas occurs in the combustion chamber. Note that the second mixed gas fuel does not contain the first off-gas.

[0086] Next, a fuel purification plant startup step (S12) is executed. Specifically (also referring to FIG. 11), the distillation purification device 103 is started, and the boiler vapor on-off valve 82B is opened, and boiler vapor as a heat source is supplied to the distillation purification device 103. At this time, the distillation purification device 103 distills and purifies the bio-liquid fuel supplied by the bio-liquid fuel supply line 291. When S12 is executed, the crude oil supply facility 109 does not have to operate.

[0087] Next, by opening the first off-gas on-off valve 117, a first off-gas supply step (S14) is executed in which the first off-gas supply line 110 supplies the first off-gas to the gas mixing device 8. As a result, the gas mixing device 8 generates a mixed gas fuel containing fuel gas, the first off-gas, and the second off-gas. Then, a mixed gas fuel supply step (S21) is executed in which the mixed gas fuel is supplied to the combustor 3 via the mixed gas fuel supply line 4.

[0088] Next, a recovered water supply switching step (S22) is executed. In S22, similar to S13 according to the first embodiment, the high-temperature feed water on-off valve 48 is closed and the low-temperature feed water on-off valve 45 is opened. Thereby, even when impurities are contained in the recovered water due to the combustion of the mixed gas fuel containing the first off-gas, the recovered water from which the impurities have been removed can be supplied to the makeup water tank 17. Note that if the amount of impurities in the exhaust gas 13 is less than the allowable value during the combustion of the first mixed gas fuel, S22 may not be executed.

[0089] After the execution of S22, S23 to S31 in FIG. 8 are executed, and the startup method of the plant 1 according to the second embodiment ends. To avoid duplication of explanation, the detailed description of S23 to S31 according to the second embodiment is omitted.

[0090] The advantages obtained by the startup method of the plant 1 according to the second embodiment described above will be described. However, the description of the same advantages as those obtained by the startup method of the plant 1 according to the first embodiment will be omitted.

[0091] According to the configuration in which the bio-liquid fuel production plant startup step (S2) is executed before the execution of the fuel refining plant 100 startup step (S12), for the bio-liquid fuel production plant 200 with a relatively large steam consumption, boiler steam can be supplied early, so that the boiler steam discharged from the started waste heat recovery boiler 14 can be effectively utilized early. Also, in the mixed gas fuel supply step (S21), since a mixed gas fuel containing fuel gas, first off-gas, and second off-gas can be supplied to the gas turbine 9, the calorific value obtained by combustion in the combustor 3 can be ensured, and the high-temperature combustion gas 12 can be supplied to the turbine 2 to drive the gas turbine 9. Therefore, a startup method of the plant 1 equipped with the cogeneration system 10 using the second off-gas obtained in the production process of bio-liquid fuel as fuel is realized. Further, since the second off-gas is used as fuel, the consumption of fuel gas with a large calorific value per unit mass can be reduced, contributing to carbon neutrality.

[0092] In the above startup method, the second mixed gas fuel supply step (S10) is executed after the bio-liquid fuel production plant startup step (S2). According to the above configuration, by supplying the second mixed gas fuel to the combustor 3 of the gas turbine 9, the combustion environment in the combustor 3, such as the hydrogen gas concentration in the combustion chamber or the temperature of the combustion chamber, can be adjusted to the combustion environment for supplying the mixed gas fuel containing the first off-gas to the gas turbine 9.

[0093] In the above startup method, the second off-gas supply step (S8) is executed before the first off-gas supply step (S14), and the second mixed gas fuel supply step (S10) is executed after the startup fuel supply step (S1) and before the mixing fuel gas supply step (S21). In other words, the second off-gas supply line 220 is configured to start supplying the second off-gas before the start of the supply of the first off-gas by the first off-gas supply line 110, and the mixed gas fuel supply line 4 is configured to supply the second mixed gas fuel generated by the gas mixer 8 to the combustor 3 before the start of the supply of the first off-gas by the first off-gas supply line 110. According to the above configuration, the second mixed gas fuel containing the fuel gas and the second off-gas is supplied to the combustor 3. Thereby, it becomes possible to optimize the combustion environment in the combustor 3, such as the hydrogen gas concentration in the combustion chamber or the temperature of the combustion chamber, for the mixed gas fuel containing the fuel gas, the first off-gas, and the second off-gas.

[0094] <8. Method for retrofitting Plant 1> Referring to FIGS. 18 to 21, a method for retrofitting Plant 1A, which is the plant 1 before retrofitting, will be described. FIG. 18 is a flowchart showing a method for retrofitting Plant 1A according to an embodiment of the present disclosure. FIG. 19 is a schematic diagram of Plant 1A according to an embodiment of the present disclosure. FIG. 20 is a schematic diagram of Plant 1B, which is the plant 1 during retrofitting, according to an embodiment of the present disclosure. FIG. 21 is a schematic diagram of the plant 1 after retrofitting according to an embodiment of the present disclosure.

[0095] The retrofitting of Plant 1 is executed by an operator, a robotic device operated by the operator, or a combination thereof. The method for retrofitting Plant 1 described below includes a method for retrofitting the cogeneration system 10.

[0096] Prior to the description of the retrofit method, the plant 1A, which is the plant 1 before retrofit, will be described with reference to FIG. 19. The plant 1A includes a cogeneration system 10A, which is the cogeneration system 10 before retrofit, and a fuel refining plant 100. Further, the plant 1A is provided with a boiler steam supply line 82. On the other hand, the plant 1A is not provided with a bio-liquid fuel production plant 200 and a steam supply line 87 for a gasifying agent. Further, the cogeneration system 10A is not provided with a water recovery system 40, an exhaust damper 31, a water extraction line 49, a water extraction on-off valve 50, an electrolysis device 61, an oxygen gas supply line 64, and a hydrogen gas supply line 68.

[0097] The retrofit method of the plant 1A will be described. As shown in FIGS. 18 to 20, first, a step of adding a steam supply line 87 for a gasifying agent (step S101) and a step of adding a second off-gas supply line 220 (step S103) are sequentially executed. When steps S101 and S103 are executed, a step of adding a bio-liquid fuel production plant 200 to the plant 1A is also executed. In S101, a steam supply pipe 87A for a gasifying agent is connected to a boiler steam supply pipe 82A and a steam supply device 201 (see FIG. 3), and a boiler steam on-off valve 82B is provided in the boiler steam supply pipe 82A. Further, in S103, a second off-gas supply pipe 225 is connected to a second off-gas supply device 270 and a gas mixing device 8, and a second off-gas on-off valve 227 is provided in the second off-gas supply pipe 225. Thereby, the plant 1A is retrofitted into the plant 1B (see FIG. 20).

[0098] As shown in FIGS. 18, 20, and 21, a water recovery system addition step (S105) of adding a water recovery system 40, an electrolysis device addition step (S107) of adding an electrolysis device 61, an oxygen gas supply line addition step (S109) of adding an oxygen gas supply line 64, and a hydrogen gas supply line addition step (S111) of adding a hydrogen gas supply line 68 are sequentially executed. In S105, an operation of adding an exhaust damper 31 to the exhaust line 29 is also executed. In S07, an operation of adding a pumping line 49 and a pumping on-off valve 50 is also executed. In S109, an operation of connecting an oxygen gas supply pipe 64A to the electrolysis device 61 and an oxygen gas supply device 205 (see FIG. 3) is executed, and an operation of connecting an oxygen gas generation device 209 (see FIG. 3) and the oxygen gas supply pipe 64A with an oxygen gas discharge pipe 207 (see FIG. 3) is executed. In S111, an operation of connecting the electrolysis device 61 and a biomass gas discharge pipe 280 (see FIG. 6) with a hydrogen gas supply pipe 68A is executed.

[0099] Through the above steps, the plant 1 is completed (see FIG. 21). The advantages realized by the plant 1 are as described above, and a method for retrofitting the cogeneration system 10 that drives with the second off-gas obtained in the process of generating bio-liquid fuel from biomass as fuel is realized. Also, since the second off-gas is used as fuel, a method for retrofitting the cogeneration system 10 that can reduce the consumption of fuel gas with a large calorific value per unit mass and contribute to carbon neutrality is realized.

[0100] Note that the execution order of the above steps may be changed as appropriate. For example, S105 may be executed before S101 and S103. Also, S107 to S111 may be executed before S105. Furthermore, S105 to S111 may not be executed. In this case, Plant 1B (see FIG. 20) is a retrofitted plant. Even in Plant 1B, the second off-gas generated in the process of generating bio-liquid fuel from biomass can be used as fuel for the combustor 3 together with the fuel gas and the first off-gas. Thereby, since the calorific value obtained by combustion in the combustor 3 can be ensured, the combustion gas 12 supplied to the turbine 2 can be heated to a high temperature, and the gas turbine 9 can be driven. That is, the method for retrofitting the cogeneration system 10 is established as a method for retrofitting the cogeneration system 10 that drives using the second off-gas as fuel even without including S105 to S111.

[0101] <9. Summary> The content described in several of the above-described embodiments is understood as follows, for example.

[0102] 1) The startup method of the plant (1) according to at least one embodiment of the present disclosure is a gas turbine cogeneration system (10) including a gas turbine (9), a heat recovery boiler (14), and a fuel gas supply line (70) for supplying fuel gas to the gas turbine, a bio-liquid fuel production plant (200) including a gasifier (233) for producing biomass gas from biomass and a bio-liquid fuel production device (290) for producing bio-liquid fuel from the biomass gas, a fuel purification plant (100) for purifying fuel from the bio-liquid fuel produced with the bio-liquid fuel using the boiler steam discharged from the heat recovery boiler as a heat source and is a startup method of a plant comprising: a cogeneration system startup step (S1) for starting the gas turbine cogeneration system, a fuel purification plant startup step (S3) for starting the supply of the boiler steam to the fuel purification plant after the execution of the cogeneration system startup step After the execution of the fuel refining plant startup step, a bio-liquid fuel production plant startup step (S15) for starting the gasifier and the bio-liquid fuel production device; After the execution of the bio-liquid fuel production plant startup step, a mixed gas fuel supply step (S21) for starting to supply a mixed gas fuel including the fuel gas, the first off-gas generated in the fuel refining plant, and the second off-gas having a calorific value per unit mass smaller than that of the fuel gas and generated in the bio-liquid fuel production device to the gas turbine; It includes.

[0103] According to the configuration of 1) above, since the fuel refining plant startup step is executed before the bio-liquid fuel production plant startup step, the fuel refining plant can immediately accept the bio-liquid fuel produced by the bio-liquid fuel production device. Therefore, the time from when the bio-liquid fuel is produced until the fuel is refined can be shortened. Also, in the mixed gas fuel supply step, since a mixed gas fuel including the fuel gas, the first off-gas, and the second off-gas can be supplied to the gas turbine, the calorific value obtained by combustion in the combustor can be ensured, and high-temperature combustion gas (12) can be supplied to the turbine to drive the gas turbine. Thus, a plant startup method including a gas turbine cogeneration system using the second off-gas obtained in the process of producing bio-liquid fuel as fuel is realized. Also, since the second off-gas is used as fuel, the consumption of the fuel gas having a large calorific value per unit mass can be reduced, contributing to carbon neutrality.

[0104] 2) In some embodiments, the plant startup method described in 1) above Further includes a gasifying agent supply step (S29) for starting to supply the boiler steam to the gasifier as the gasifying agent for the biomass after the execution of the cogeneration system startup step.

[0105] Generally, a large amount of boiler steam is required in the process of generating biomass gas from biomass. In this regard, according to the configuration of the above (2), the steam as a gasifying agent required for generating biomass gas can be covered by the boiler steam discharged from the exhaust heat recovery boiler. Since the amount of boiler steam discharged from the exhaust heat recovery boiler is very large, it is possible to avoid the shortage of steam as a gasifying agent in the gasification device, and it becomes possible to generate a sufficient amount of biomass gas.

[0106] 3) In some embodiments, it is a method for starting the plant described in the above (1) or (2), The gas turbine cogeneration system, A water recovery device (33) for recovering moisture from the exhaust gas by heat exchange between the exhaust gas discharged from the exhaust heat recovery boiler and the refrigerant water, A recovered water cooling device (36) for cooling the recovered water containing the moisture recovered by the water recovery device, A recovered water supply line (42) for supplying the recovered water cooled by the recovered water cooling device to the water recovery device as the refrigerant water, A recovered water discharge line (39) for supplying the recovered water discharged from the water recovery device to the recovered water cooling device, A makeup water tank (17) for storing boiler feed water to be supplied to the exhaust heat recovery boiler, A high-temperature feed water line connected to the recovered water discharge line, which is a high-temperature feed water line (44) for supplying the recovered water taken out from the recovered water discharge line to the makeup water tank further includes, In the cogeneration system startup step, the water recovery device starts recovering the moisture from the exhaust gas, and the high-temperature feed water line starts supplying the recovered water.

[0107] According to the configuration of 3) above, while the gas turbine cogeneration system performs a startup operation, the recovered water is supplied to the makeup water tank by the high-temperature feed water line. As a result, the boiler feed water supplied to the waste heat recovery boiler can be heated to a high temperature, so that the operating efficiency of the gas turbine cogeneration system can be improved.

[0108] 4) In some embodiments, it is a method for starting up the plant described in 3) above, wherein the gas turbine cogeneration system is a low-temperature feed water line connected to the recovered water supply line, and is a low-temperature feed water line (47) for supplying the recovered water taken out from the recovered water supply line to the makeup water tank, and a water treatment device (46) for performing a treatment to remove impurities from the recovered water flowing through the low-temperature feed water line and further includes wherein the method for starting up the plant after executing the fuel refining plant startup step, a first mixed gas fuel supply step (S11) of supplying a first mixed gas fuel including the fuel gas and the first off-gas to the gas turbine; when executing the first mixed gas fuel supply step, further includes a recovered water supply switching step (S13) of stopping the supply of the recovered water by the high-temperature feed water line and starting the supply of the recovered water by the low-temperature feed water line.

[0109] According to the configuration of 4) above, in the first mixed gas fuel supply step, the first mixed gas fuel is supplied to the combustor of the gas turbine. As a result, the combustion environment in the combustor 3, such as the hydrogen gas concentration in the combustion chamber or the temperature of the combustion chamber, can be adjusted to the combustion environment for supplying the mixed gas fuel containing the second off-gas to the gas turbine. On the other hand, the first mixed gas fuel containing the first off-gas contains a certain degree of impurities, and there is a concern that the impurities in the exhaust gas may exceed the allowable value. In this regard, according to the configuration of 4) above, after the execution of the fuel purification plant startup step, the recovered water supply switching step is executed. The low-temperature water supply line supplies the recovered water instead of the high-temperature water supply line, and in this supply process, the water treatment device can remove the impurities contained in the recovered water. Thereby, it is possible to avoid the corrosion of the equipment caused by the adhesion of impurities to the equipment constituting the gas turbine cogeneration system.

[0110] 5) In some embodiments, it is a method for starting up the plant described in 3) or 4) above, The gas turbine cogeneration system is, An electrolysis device (61) for subjecting the recovered water discharged from the water recovery device to electrolysis treatment, An oxygen gas supply line (64) for supplying the oxygen gas generated by the electrolysis device to the bio-liquid fuel production plant as a gasifying agent to be used in the gasifying device, Further includes, The method for starting up the plant is, An electrolysis device startup step (S23) for starting up the electrolysis device, After the execution of the electrolysis device startup step, an oxygen gas supply step (S25) for starting the supply of the oxygen gas through the oxygen gas supply line, Further includes.

[0111] According to the configuration of 5) above, by sequentially executing the electrolysis device startup step and the oxygen gas supply step, the oxygen gas obtained by using the recovered water recovered by the water recovery device can be used as a gasifying agent in the gasifying device. Thereby, it is possible to utilize the moisture contained in the exhaust gas and supply a sufficient amount of gasifying agent to the gasifying device.

[0112] 6) In some embodiments, a method for starting up a plant according to any one of 3) to 5) above, the gas turbine cogeneration system includes an electrolysis device (61) for subjecting the recovered water discharged from the water recovery device to electrolysis treatment, a hydrogen gas supply line (68) for supplying the hydrogen gas generated in the electrolysis device to the bio-liquid fuel generation device, and further includes the method for starting up the plant includes an electrolysis device startup step (S23) for starting up the electrolysis device, after the execution of the electrolysis device startup step, a hydrogen gas supply step (S31) for starting the supply of the hydrogen gas through the hydrogen gas supply line, and further includes.

[0113] According to the configuration of 6) above, by sequentially executing the electrolysis device startup step and the hydrogen gas supply step, the hydrogen gas obtained by using the recovered water recovered by the water recovery device can be used for the production of bio-liquid fuel. Thereby, the moisture contained in the exhaust gas can be utilized to supply a sufficient amount of hydrogen gas to the bio-liquid fuel.

[0114] 7) In some embodiments, a method for starting up a plant according to any one of 1) to 6) above, the bio-liquid fuel generation plant further includes an oxygen gas generation device (209) for supplying oxygen gas taken out from air to the gasification device, the method for starting up the plant further includes an oxygen gas generation device startup step (S27) for starting up the oxygen gas generation device after the execution of the fuel purification plant startup step.

[0115] According to the configuration of 7) above, it is possible to avoid a shortage of oxygen gas to be supplied to the gasification device.

[0116] 8) The startup method of the plant (1) according to at least one embodiment of the present disclosure is as follows: A gas turbine cogeneration system (10) including a gas turbine (9), a heat recovery boiler (14), and a fuel gas supply line (70) for supplying fuel gas to the gas turbine, A biomass liquid fuel production plant (200) including a gasifier (233) for generating biomass gas from biomass and a biomass liquid fuel production device (290) for generating biomass liquid fuel from the biomass gas, A fuel purification plant (100) for purifying fuel from the biomass liquid fuel produced with the biomass liquid fuel using the boiler steam discharged from the heat recovery boiler as a heat source The startup method of a plant comprising: A cogeneration system startup step (S1) of starting up the gas turbine cogeneration system; After the execution of the cogeneration system startup step, starting the supply of the boiler steam as a gasifying agent to the gasifier, and a biomass liquid fuel production plant startup step (S2) of starting up the gasifier and the biomass liquid fuel production device; After the execution of the biomass liquid fuel production plant startup step, a fuel purification plant startup step (S14) of starting the supply of the boiler steam to the fuel purification plant; After the execution of the fuel purification plant startup step, starting to supply a mixed gas fuel including the fuel gas, a first off-gas generated in the fuel purification plant, and a second off-gas having a calorific value per unit mass generated in the biomass liquid fuel production device smaller than that of the fuel gas to the gas turbine in a mixed gas fuel supply step (S21); Comprising.

[0117] According to the configuration of 8) above, for a bio-liquid fuel production plant with a relatively large steam consumption, boiler steam can be supplied early, so that the boiler steam discharged from the exhaust heat recovery boiler of the started gas turbine cogeneration system can be effectively utilized early. Further, in the mixed gas fuel supply step, a mixed gas fuel including fuel gas, first off-gas, and second off-gas can be supplied to the gas turbine, so that the calorific value obtained by combustion in the combustor can be ensured, and high-temperature combustion gas can be supplied to the turbine to drive the gas turbine. Therefore, a plant startup method for a gas turbine cogeneration system using the second off-gas obtained in the bio-liquid fuel production process as fuel is realized. Further, since the second off-gas is used as fuel, the consumption of fuel gas with a large calorific value per unit mass can be reduced, contributing to carbon neutrality.

[0118] 9) In some embodiments, it is a plant startup method according to 8) above, The gas turbine cogeneration system is a water recovery device (33) for recovering moisture from the exhaust gas by heat exchange between the exhaust gas discharged from the exhaust heat recovery boiler and refrigerant water, a recovered water cooling device (36) for cooling the recovered water containing the moisture recovered by the water recovery device, a recovered water supply line (42) for supplying the recovered water cooled by the recovered water cooling device to the water recovery device as the refrigerant water, a recovered water discharge line (39) for supplying the recovered water discharged from the water recovery device to the recovered water cooling device, a makeup water tank (17) for storing boiler feed water to be supplied to the exhaust heat recovery boiler, a high-temperature feed water line connected to the recovered water discharge line, which is a high-temperature feed water line (44) for supplying the recovered water taken out from the recovered water discharge line to the makeup water tank and further includes, In the cogeneration system startup step, the water recovery device starts recovering the moisture from the exhaust gas, and the high-temperature feed water line starts supplying the recovered water.

[0119] According to the configuration of the above (9), the same operational effects as those of the above (3) can be obtained.

[0120] 10) In some embodiments, it is a method for starting up the plant described in the above (9), wherein the gas turbine cogeneration system includes a low-temperature feed water line connected to the recovered water supply line, the low-temperature feed water line (47) for supplying the recovered water taken out from the recovered water supply line to the makeup water tank, and a water treatment device (46) for performing a treatment to remove impurities from the recovered water flowing through the low-temperature feed water line and further includes wherein the method for starting up the plant further includes a second mixed gas fuel supply step of supplying a second mixed gas fuel including the fuel gas and the second off-gas to the gas turbine after the execution of the bio-liquid fuel production plant startup step.

[0121] According to the configuration of the above (10), in the second mixed gas fuel supply step, by supplying the second mixed gas fuel to the combustor of the gas turbine, the combustion environment in the combustor 3, such as the hydrogen gas concentration in the combustion chamber or the temperature of the combustion chamber, can be adjusted to the combustion environment for supplying a mixed gas fuel including the first off-gas to the gas turbine.

[0122] 11) In some embodiments, it is a method for starting up the plant described in the above (9) or (10), wherein the gas turbine cogeneration system includes an electrolysis device (61) for performing electrolysis treatment on the recovered water discharged from the water recovery device, and an oxygen gas supply line (64) for supplying the oxygen gas generated by the electrolysis device to the bio-liquid fuel production plant as a gasifying agent to be used in the gasification device and further includes wherein the method for starting up the plant An electrolyzer startup step (S23) for starting up the electrolyzer An oxygen gas supply step (S25) for starting the supply of the oxygen gas through the oxygen gas supply line after the execution of the electrolyzer startup step further includes.

[0123] According to the configuration of the above 11), the same operational effects as those of the above 5) can be obtained.

[0124] 12) In some embodiments, it is a method for starting up the plant according to any one of the above 9) to 11), the gas turbine cogeneration system an electrolyzer (61) for subjecting the recovered water discharged from the water recovery device to electrolysis treatment, a hydrogen gas supply line (68) for supplying the hydrogen gas generated in the electrolyzer to the bio-liquid fuel generation device further includes, the method for starting up the plant an electrolyzer startup step (S23) for starting up the electrolyzer a hydrogen gas supply step (S31) for starting the supply of the hydrogen gas through the hydrogen gas supply line after the execution of the electrolyzer startup step further includes.

[0125] According to the configuration of the above 12), the same operational effects as those of the above 6) can be obtained.

[0126] 13) In some embodiments, it is a method for starting up the plant according to any one of the above 8) to 12), the bio-liquid fuel generation plant further includes an oxygen gas generation device for supplying oxygen gas taken out from the air to the gasification device, the method for starting up the plant further includes an oxygen gas generation device startup step (S27) for starting up the oxygen gas generation device after the execution of the fuel purification plant startup step.

[0127] According to the configuration of the above (13), the same operational effects as those of the above (7) can be obtained.

Explanation of Signs

[0128] 1, 1A, 1B: Plant 2: Turbine 3: Combustor 4: Mixed gas fuel supply line 4A: Mixed gas fuel supply pipe 4B: Mixed gas fuel on-off valve 5: Generator 6: Compressor inlet air 7: Compressed air 8: Gas mixing device 9: Gas turbine 10, 10A: Gas turbine cogeneration system (cogeneration system) 11: Steam demand unit 12: Combustion gas 13: Exhaust gas 14: Exhaust heat recovery boiler 15: Feed water line 16: Compressor 17: Makeup water tank 18: Feed water pump 19: Feed water line 21: Steam supply pipe 29: Exhaust line 30: Exhaust tower 31: Exhaust damper 33: Water recovery device 34: Sprinkler device 35: Filler 36: Recovered water cooling device 38: Water recovery pump 39: Recovered water discharge line 40: Water recovery system 41: Cooling water supply line 42: Recovered water supply line 43: Feed water line 44: High-temperature feed water line 45: Low-temperature feed water on-off valve 46: Water treatment device 47: Low-temperature feed water line 48: High-temperature feed water on-off valve 49: Pumping line 50: Pumping on-off valve 55: Cooling water supply pump 57: Exhaust gas supply line 59: Water recovery damper 60: Fuel supply system 61: Electrolyzer 62: Fuel gas supply source 64: Oxygen gas supply line 64A: Oxygen gas supply pipe 64B: Oxygen gas on-off valve 68: Hydrogen gas supply line 68A: Hydrogen gas supply pipe 68B: Hydrogen gas on-off valve 70: Fuel gas supply line 72: Starting fuel gas supply line 72A: Starting fuel gas supply pipe 72B: Starting fuel gas on-off valve 77: Mixed fuel gas supply line 77A: Mixed fuel gas supply pipe 77B: Mixed fuel gas on-off valve 82: Boiler steam supply line 82A: Boiler steam supply pipe 82B: Boiler steam on-off valve 87: Steam supply line for gasifying agent 87A: Steam supply pipe for gasifying agent 87B: Steam on-off valve for gasifying agent 90: Controller 100: Fuel purification plant 103: Distillation purification device 105: Fuel storage facility 107: First off-gas discharge pipe 109: Crude oil supply facility 110: First off-gas supply line 115: First off-gas supply pipe 117: First off-gas on-off valve 130: Steam extraction pipe 135: Heat exchange container 136: Water storage tank 146: Ion exchange resin 170: First off-gas supply device 200: Bio-liquid fuel production plant 201: Steam supply device 203: Biomass supply device 205: Oxygen gas supply device 207: Oxygen gas discharge pipe 209: Oxygen gas generation device 220: Second off-gas supply line 221: Steam supply pipe 221A: Steam on-off valve 223: Biomass supply pipe 223A: Biomass on-off valve 225: Second off-gas supply pipe 227: Second off-gas on-off valve 233: Gasification device 235: Oxygen gas supply pipe 235A: Oxygen gas on-off valve 237: Second off-gas discharge pipe 270: Second off-gas supply device 280: Biomass gas discharge pipe 280A: Biomass gas on-off valve 290: Bio-liquid fuel production device 291: Bio-liquid fuel supply line 291A: Bio-liquid fuel supply pipe 291B: Bio-liquid fuel on-off valve

Claims

1. A gas turbine cogeneration system including a gas turbine, a heat recovery boiler, and a fuel gas supply line for supplying fuel gas to the gas turbine, A bio-liquid fuel production plant including a gasification device for producing biomass gas from biomass and a bio-liquid fuel production device for producing bio-liquid fuel from the biomass gas, A fuel purification plant for purifying fuel from the bio-liquid fuel produced in the bio-liquid fuel production plant using the boiler steam discharged from the heat recovery boiler as a heat source A method for starting up a plant comprising: A cogeneration system startup step of starting up the gas turbine cogeneration system, A fuel purification plant startup step of starting to supply the boiler steam to the fuel purification plant after execution of the cogeneration system startup step, A bio-liquid fuel production plant startup step of starting up the gasification device and the bio-liquid fuel production device after execution of the fuel purification plant startup step, A mixed gas fuel supply step of starting to supply a mixed gas fuel including the fuel gas, a first off-gas generated in the fuel purification plant, and a second off-gas having a calorific value per unit mass smaller than that of the fuel gas and generated in the bio-liquid fuel production device to the gas turbine after execution of the bio-liquid fuel production plant startup step A method for starting up a plant.

2. Further comprising a gasification agent supply step of starting to supply the boiler steam to the gasification device as a gasification agent for the biomass after execution of the cogeneration system startup step The method for starting up a plant according to Claim 1.

3. The gas turbine cogeneration system A water recovery device for recovering moisture from the exhaust gas by heat exchange between the exhaust gas discharged from the heat recovery boiler and refrigerant water, A recovered water cooling device for cooling the recovered water containing the moisture recovered by the water recovery device, A recovered water supply line for supplying the recovered water cooled by the recovered water cooling device to the water recovery device as the refrigerant water, A recovered water discharge line for supplying the recovered water discharged from the water recovery device to the recovered water cooling device, A makeup water tank for storing makeup water for supplying to the exhaust heat recovery boiler, A high-temperature water supply line connected to the recovered water discharge line, for supplying the recovered water taken out from the recovered water discharge line to the makeup water tank and further includes, In the cogeneration system startup step, the water recovery device starts recovering the moisture from the exhaust gas, and the high-temperature water supply line starts supplying the recovered water. The startup method of the plant according to claim 1 or 2.

4. The gas turbine cogeneration system, A low-temperature water supply line connected to the recovered water supply line, for supplying the recovered water taken out from the recovered water supply line to the makeup water tank, A water treatment device for performing a treatment to remove impurities from the recovered water flowing through the low-temperature water supply line and further includes, The startup method of the plant, After executing the fuel refining plant startup step, a first mixed gas fuel supply step of supplying a first mixed gas fuel containing the fuel gas and the first off-gas to the gas turbine, When executing the first mixed gas fuel supply step, further includes a recovered water supply switching step of stopping the supply of the recovered water by the high-temperature water supply line and starting the supply of the recovered water by the low-temperature water supply line. The startup method of the plant according to claim 3.

5. The gas turbine cogeneration system, An electrolysis device for subjecting the recovered water discharged from the water recovery device to electrolysis treatment, An oxygen gas supply line for supplying the oxygen gas generated by the electrolysis device to the bio-liquid fuel production plant as a gasifying agent to be used in the gasification device, further comprising, The startup method of the plant is, An electrolysis device startup step of starting the electrolysis device, After the execution of the electrolysis device startup step, an oxygen gas supply step of starting the supply of the oxygen gas through the oxygen gas supply line, further comprising The startup method of the plant according to claim 3.

6. The gas turbine cogeneration system is, An electrolysis device for subjecting the recovered water discharged from the water recovery device to electrolysis treatment, A hydrogen gas supply line for supplying the hydrogen gas generated in the electrolysis device to the bio-liquid fuel production device further comprising, The startup method of the plant is, An electrolysis device startup step of starting the electrolysis device, After the execution of the electrolysis device startup step, a hydrogen gas supply step of starting the supply of the hydrogen gas through the hydrogen gas supply line, further comprising The startup method of the plant according to claim 3.

7. The bio-liquid fuel production plant further includes an oxygen gas generation device for supplying oxygen gas taken out from the air to the gasification device, The startup method of the plant further includes an oxygen gas generation device startup step of starting the oxygen gas generation device after the execution of the fuel purification plant startup step The startup method of the plant according to claim 1 or 2.

8. A gas turbine cogeneration system including a gas turbine, a waste heat recovery boiler, and a fuel gas supply line for supplying fuel gas to the gas turbine, A bio-liquid fuel production plant including a gasifier for producing biomass gas from biomass and a bio-liquid fuel production device for producing bio-liquid fuel from the biomass gas, A fuel purification plant for purifying fuel from the bio-liquid fuel produced in the bio-liquid fuel production plant using the boiler steam discharged from the waste heat recovery boiler as a heat source A method for starting up a plant comprising: A cogeneration system startup step of starting up the gas turbine cogeneration system, After the execution of the cogeneration system startup step, starting to supply the boiler steam as a gasifying agent to the gasifier, and a bio-liquid fuel production plant startup step of starting up the gasifier and the bio-liquid fuel production device, After the execution of the bio-liquid fuel production plant startup step, a fuel purification plant startup step of starting to supply the boiler steam to the fuel purification plant, After the execution of the fuel purification plant startup step, starting to supply a mixed gas fuel including the fuel gas, a first off-gas generated in the fuel purification plant, and a second off-gas having a calorific value per unit mass generated in the bio-liquid fuel production device and smaller than that of the fuel gas to the gas turbine A method for starting up a plant.

9. The gas turbine cogeneration system includes: A water recovery device for recovering moisture from the exhaust gas by heat exchange between the exhaust gas discharged from the waste heat recovery boiler and the refrigerant water, A recovered water cooling device for cooling the recovered water containing the moisture recovered by the water recovery device, A recovered water supply line for supplying the recovered water cooled by the recovered water cooling device to the water recovery device as the refrigerant water, A recovered water discharge line for supplying the recovered water discharged from the water recovery device to the recovered water cooling device, A makeup water tank for storing boiler feed water to be supplied to the exhaust heat recovery boiler, A high-temperature feed water line connected to the recovered water discharge line, the high-temperature feed water line for supplying the recovered water taken out from the recovered water discharge line to the makeup water tank and further includes In the cogeneration system startup step, the water recovery device starts recovering the moisture from the exhaust gas, and the high-temperature feed water line starts supplying the recovered water The startup method of the plant according to claim 8.

10. The gas turbine cogeneration system, A low-temperature feed water line connected to the recovered water supply line, the low-temperature feed water line for supplying the recovered water taken out from the recovered water supply line to the makeup water tank, A water treatment device for performing a treatment to remove impurities from the recovered water flowing through the low-temperature feed water line and further includes The startup method of the plant, After executing the bio-liquid fuel generation plant startup step, further includes a second mixed gas fuel supply step of supplying a second mixed gas fuel including the fuel gas and the second off-gas to the gas turbine, The startup method of the plant according to claim 9.

11. The gas turbine cogeneration system, An electrolysis device for performing electrolysis treatment on the recovered water discharged from the water recovery device, An oxygen gas supply line for supplying the oxygen gas generated by the electrolysis device to the bio-liquid fuel generation plant as a gasifying agent to be used in the gasification device, and further includes The startup method of the plant, An electrolysis device startup step of starting the electrolysis device, After executing the electrolyzer startup step, an oxygen gas supply step of starting the supply of the oxygen gas through the oxygen gas supply line, further comprising The method for starting up the plant according to claim 9 or 10.

12. The gas turbine cogeneration system an electrolyzer for subjecting the recovered water discharged from the water recovery device to electrolysis treatment; a hydrogen gas supply line for supplying the hydrogen gas generated in the electrolyzer to the bio-liquid fuel generation device further including The method for starting up the plant an electrolyzer startup step of starting up the electrolyzer; after executing the electrolyzer startup step, a hydrogen gas supply step of starting the supply of the hydrogen gas through the hydrogen gas supply line, further comprising The method for starting up the plant according to claim 9 or 10.

13. The bio-liquid fuel generation plant further includes an oxygen gas generation device for supplying oxygen gas taken out from the air to the gasification device, The method for starting up the plant further comprises an oxygen gas generation device startup step of starting up the oxygen gas generation device after executing the fuel purification plant startup step The method for starting up the plant according to claim 8 or 9.

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