JP5883374B2 - Plant operating method, mixed fuel manufacturing method and plant - Google Patents

Description

  The present invention relates to a plant operating method, a mixed fuel manufacturing method, and a plant that can effectively use sewage sludge having a low calorific value.

  In recent years, there has been a demand for effective use of resources and reduction of waste, and biomass and waste are used as fuel for power generation facilities. As one form of such biomass, a sludge treated product obtained by treating sewage sludge generated at a sewage treatment plant is known (see, for example, Patent Document 1). The sludge treated product includes a sludge dried product obtained by drying sewage sludge and a carbonized sludge carbide product.

  The sludge treated product becomes gasified gas by gasification, and is effectively used by burning the gasified gas. For this gasification, for example, there is a fluidized bed gasification furnace as described in Non-Patent Document 1. However, since the sludge treatment product contains a large amount of various heavy metals, it is necessary to pay attention to industrial waste treatment for the elution of heavy metals from the ash. Therefore, it is possible to positively discharge heavy metals with molten slag and to use a spouted bed gasification furnace with excellent tar decomposition performance, stabilizing the heavy metal treatment, affecting the equipment after the gasification furnace, and residue Considering volume reduction, it is considered desirable.

  There are the following requirements for gasification of sludge treated products with a spouted bed gasifier. That is, (1) it can be maintained at a temperature higher than the melting point of the ash content in the sludge treated product, and slag can be melted and stably discharged, and (2) power can be generated using an internal combustion engine that burns gasified gas, for example, a gas turbine. It is to generate a gasification gas having a calorific value.

  The sludge treatment product contains a large amount of ash, and its calorific value is relatively small. For this reason, the requirement (2) cannot be satisfied even if the sludge treatment product is simply gasified in the spouted bed gasifier. Also, if the combustion reaction is reduced by lowering the oxygen ratio in the spouted bed gasifier, the calorific value of the gasified gas will increase, but the temperature in the spouted bed gasifier will be below the melting point of ash and melt the slag. And stable discharge may not be possible. That is, the above requirement (1) cannot be satisfied.

  The sludge treatment product is very inexpensive, and effective use is desired because stable supply is expected especially in urban areas. However, only the sludge treatment product is used for gasification in spouted bed gasification and its gas. Power generation using chemical gas is difficult.

  In addition, it has been proposed to gasify and use a mixed fuel obtained by mixing woody biomass with a small amount of ash and a high calorific value in the sludge treated product (see, for example, Non-Patent Document 1). However, Non-Patent Document 1 uses a fluidized bed gasification furnace and does not need to actively melt slag. In other words, the above requirements (1) and (2) in the spouted bed gasifier are not taken into consideration.

JP 2008-13377 A

Makoto Sugaya, Satoshi Takahashi, “Development of Highly Efficient Gasification and Utilization Technology Using Biomass”, Tokyo Metropolitan Sewerage Bureau Technical Survey Annual Report 2007

  In view of such circumstances, the present invention has a high calorific value, is inexpensive, and can operate a mixed fuel suitable for gasification in a spouted bed gasifier, and a method for producing the mixed fuel And a plant capable of using the mixed fuel.

A first aspect for achieving the above object is a spouted bed gasification furnace for producing gasified gas from mixed fuel and oxygen, which are a mixture of biomass and sludge-treated product obtained by treating sewage sludge, and the gasified gas. An operation method of a plant comprising an internal combustion engine that obtains power as a fuel, the thermodynamic equilibrium calculation of the mixed fuel based on the ash content composition of the mixed fuel obtained by mixing the biomass and the sludge treatment product at a predetermined mixing ratio a first step of obtaining the melting point T _Am ash, obtained by burning calculate the temperature at the time of combusting the mixed fuel in a predetermined oxygen ratio, and the temperature and furnace temperature Tg of the entrained flow gasifier, the mixing a second step of obtaining the combustion calculate the calorific value of the gasified gas generated upon combustion of a fuel in a predetermined oxygen ratio, the furnace temperature Tg becomes higher the melting point T _Am, and the amount of generated heat before A third step for obtaining an oxygen ratio that satisfies the condition that the internal combustion engine can be operated and a third step for executing the third step from the first step for each of a plurality of different mixing ratios to obtain the oxygen ratio, and a plurality of different ratios. And a fourth step of supplying the mixed fuel selected from the mixing ratio to the entrained bed gasifier with an amount of oxygen corresponding to the oxygen ratio corresponding to the mixing ratio. Is in the driving method.

In such a first aspect, a mixed fuel having a lower calorific value than the sludge treated product as a whole is used by reducing the cost by mixing an inexpensive sludge treated product and biomass having a high calorific value into a mixed fuel. be able to. Although the mixed fuel is gasified in the spouted bed gasifier, the ash content is reduced by mixing the biomass, so that the ash is easily melted and discharged to the outside. As a result, the slag can be melted and discharged to the outside in the spouted bed gasification furnace, and the operation can be continued stably. In addition, the gasification gas is generated at a low cost with a high calorific value, Power generation by an internal combustion engine can be performed.
Furthermore, it has a calorific value sufficient for power generation by the internal combustion engine, and the ash content of the gasification gas can be discharged outside as a molten slag in the spouted bed gasification furnace.

A second aspect of the present invention is the plant operating method described in the first aspect, wherein, in the fourth step, the first step to the third step are executed for a plurality of different mixing ratios. The oxygen ratio is determined, and the mixed fuel having the highest ratio of the sludge treatment product and an amount of oxygen corresponding to the oxygen ratio corresponding to the mixing ratio of the mixed fuel are supplied to the spouted bed gasifier. In the operation method of the plant.

In the second aspect, since the mixed fuel is the cheapest, the operation cost of the plant can be reduced.

According to a third aspect of the present invention, in the plant operating method described in the first or second aspect, the internal combustion engine is at least one of a gas turbine, a gas engine, and a diesel engine. Is in the driving method.

In the third aspect, a gas turbine, a gas engine, and a diesel engine can be used as the internal combustion engine.

According to a fourth aspect of the present invention, there is provided a spouted bed gasification furnace that produces gasified gas by gasifying a mixed fuel obtained by mixing biomass and a sludge treatment product obtained by treating sewage sludge, and an internal combustion that burns the gasified gas. A method for producing a mixed fuel for a plant comprising an engine, wherein the ash content of the mixed fuel is calculated by thermodynamic equilibrium calculation based on an ash composition of the mixed fuel obtained by mixing the biomass and the sludge treatment product at a predetermined mixing ratio. A first step of obtaining a melting point T _Am , a temperature when the mixed fuel is burned at a predetermined oxygen ratio is obtained by combustion calculation, the temperature is set as an in-furnace temperature Tg of the spouted bed gasifier, and the mixed fuel is operating a second step of obtaining the combustion calculate the calorific value of the gasified gas generated upon combustion, the furnace temperature Tg becomes higher the melting point T _Am, and the amount of generated heat of the internal combustion engine at a predetermined oxygen ratio A third step of determining the oxygen ratio that satisfies the condition that it is ability to perform the third step from the first step for each of a plurality of different said mixing ratio determined the oxygen ratio, from a plurality of different said mixing ratio And a fourth step of producing the mixed fuel of the selected mixing ratio from the biomass and the sludge treated product .

In the fourth aspect, a mixed fuel that can generate a gasification gas having a calorific value necessary for operating an internal combustion engine and has a temperature in the furnace sufficient to melt ash in the spouted bed gasification furnace is manufactured. can do.

According to a fifth aspect of the present invention, there is provided a mixed fuel production apparatus for producing a mixed fuel by mixing biomass and a sludge treatment product obtained by treating sewage sludge, and a spouted bed for producing a gasification gas by gasifying the mixed fuel. A plant comprising a gasification furnace and an internal combustion engine for obtaining power by burning the gasification gas, wherein the mixed fuel production device is a mixed fuel obtained by mixing the biomass and the sludge treatment product at a predetermined mixing ratio. the thermodynamics equilibrium calculation based on the ash content composition sought melting point T _Am ash of the mixed fuel, obtained by burning calculate the temperature at the time of combusting the mixed fuel in a predetermined oxygen ratio, the entrained gas the temperature a furnace temperature Tg of furnace, the determined by mixing fuel combustion calculate the calorific value of the gasified gas generated when burning a predetermined oxygen ratio, the furnace temperature Tg becomes the melting point T _Am or more, or The calorific value determined oxygen ratio that satisfies the condition that it can operate the internal combustion engine, to produce the mixed fuel of the selected mixture ratio of a plurality of different said mixing ratio from the biomass and the sludge treated, the jet The bed gasification furnace is in a plant characterized by gasifying the mixed fuel supplied from the mixed fuel manufacturing apparatus at the oxygen ratio determined by the mixed fuel manufacturing apparatus .

In the fifth aspect, the internal combustion engine can be operated while using an inexpensive mixed fuel, and the ash can be melted and reliably discharged outside in the spouted bed gasification furnace.

  ADVANTAGE OF THE INVENTION According to this invention, the operating method of the plant which can produce | generate the mixed fuel suitable for the gasification in a spouted bed gasification furnace with high calorific value, cheap, the manufacturing method of this mixed fuel, and this mixed fuel A plant that can be used is provided.

It is a schematic block diagram of gasification power generation equipment. It is a schematic block diagram of gasification equipment. It is a flowchart showing the step which calculates | requires the mixture ratio of mixed fuel. Is a graph conceptually showing the calculation results of the combustor temperature The T _g obtained by thermochemical equilibrium calculations. It is a graph which shows notionally the calculation result of the calorific value of gasification gas obtained by thermochemical equilibrium calculation. It is a schematic block diagram of gasification power generation equipment.

<Embodiment 1>
In the present embodiment, a gasification power generation facility is taken as an example of a plant, and a method for producing a mixed fuel in which biomass and sludge treatment products are mixed and a method for operating the gasification power generation facility using the mixed fuel will be described.

The mixed fuel referred to in the present invention is a mixture of biomass and sludge treatment product.
In general, biomass refers to “renewable organic resources derived from living organisms (excluding fossil resources)”. For example, in addition to resource plants, crops and timber produced for the purpose of resource utilization, industrial waste such as agricultural and forestry residues and waste materials, livestock excretion discharged from the livestock industry, fishery waste, and cities Used paper, sewage sludge, and garbage.

  The biomass which concerns on this invention means things other than sewage sludge among the biomass mentioned above. In particular, the biomass according to the present invention is preferably a woody biomass made of wood. Examples of the form of the woody biomass include a chip broken into small pieces and a fine powder.

  The sludge treated product is obtained by treating sewage sludge, and examples thereof include sludge carbide and sludge dried product.

  The sludge carbide is carbonized sewage sludge generated at a sewage treatment plant or the like. The means for carbonizing the sewage sludge is not particularly limited, and a known method can be adopted. For example, after dewatering sewage sludge, sludge carbide is produced by steaming in a carbonizer. The property of the sludge carbide is powder and can be burned as it is.

  The sludge dried product is obtained by drying sewage sludge generated in a sewage treatment plant or the like. The means for drying the sewage sludge is not particularly limited, and a known method can be adopted.

  FIG. 1 is a schematic configuration diagram of a gasification power generation facility. The gasification power generation facility according to the present embodiment generates power by using power and thermal energy obtained by gasifying a mixed fuel to generate gasification gas and burning the gasification gas.

  The gasification power generation facility 1 includes an air separation device 8. The air separation device 8 cools raw material air with a cryogenic refrigerant, and separates these gases according to the boiling points of various gases such as nitrogen, oxygen, and argon contained in the raw material air. Nitrogen gas and oxygen gas produced by the air separation device 8 are supplied to the gasification facility 3. In the present embodiment, the air separation device 8 is provided, but nitrogen and oxygen may be supplied by a gas cylinder or the like.

  The gasification facility 3 is for gasifying the mixed fuel to produce gasified gas. Details of the gasification facility 3 will be described later.

  The gasification gas contains combustible components such as carbon monoxide and hydrogen gas, and also contains water-soluble impurities, condensable impurities, particulate impurities, and gaseous impurities. The gasification gas generated in the gasification furnace is dedusted by dust removing means (not shown), adjusted to a predetermined temperature by a heat exchanger (not shown), and supplied to the gas purification equipment 4.

  The gas purification equipment 4 removes impurities from the gasification gas. In the gas purification facility 4, impurities in the gasification gas are removed and fuel gas is obtained. As a method for removing impurities, there are a dry method in which the temperature of the gasification gas is maintained at a temperature above the dew point and a method of removing impurities in the gasification gas by a wet method. The configuration is not particularly limited as long as it can remove the above-described various impurities. For example, as the gas purification facility 4, an impurity removal device such as a halide removal device, a desulfurization device, an ammonia removal device, or a mercury removal device may be used. it can.

  The gas turbine 5 is supplied with the fuel gas purified by the gas purification facility 4. The gas turbine 5 is an example of an internal combustion engine, and in addition, a gas engine, a diesel engine, or the like can be used. That is, fuel gas is supplied as fuel for a gas engine or a diesel engine. In the case of a diesel engine, fuel gas is mixed and used with liquid fuel.

  Although not particularly shown, the gas turbine 5 is connected to a combustor and a compressor, and fuel gas is sent to the combustor. The gas turbine 5 obtains power by the expansion of the combustion gas generated by the combustion in the combustor. A part of the exhaust gas heat recovered by the exhaust heat recovery boiler 6 is compressed by a compressor and put into a combustor.

  The exhaust gas that has finished work in the gas turbine 5 is sent to the exhaust heat recovery boiler 6. The exhaust heat recovery boiler 6 performs heat recovery of the exhaust gas and supplies steam generated by this heat to the steam turbine 7. The steam turbine 7 obtains power by expansion of the steam supplied from the exhaust heat recovery boiler 6.

  The above-described compressor, gas turbine 5, steam turbine 7 and generator (not shown) are connected in a coaxial state, and the generator is driven by the power of the gas turbine 5 and steam turbine 7 connected in series. Then, combined power generation by the gas turbine 5 and the steam turbine 7 is performed.

  FIG. 2 is a schematic configuration diagram of the gasification facility. The gasification facility 3 includes a container 10 that stores a mixed fuel, a carbonizer 11, a gasification furnace 20, a slag hopper 21, and a char recovery device 22.

  A carbonizer 11 is connected to the gasifier 20, and a vessel 10 is connected to the carbonizer 11. A mixed fuel in which biomass and sludge treatment products are mixed at a mixing ratio determined by a method described later is accommodated in the container 10, and an appropriate amount of the mixed fuel is introduced into the carbonizer 11 from the container 10. .

  The carbonizer 11 carbonizes the mixed fuel with a high-temperature gas. The mixed fuel carbonized in the carbonizer 11 is decomposed into volatile gas (volatile content and moisture in the mixed fuel) and carbide (fixed carbon, ash, etc.), and the volatile gas is transferred to the reductor 24 and the carbide is transferred to the combustor 23. It comes to be supplied.

  The gasification furnace 20 is a spouted bed type gasification furnace, and includes a combustor 23 and a reductor 24. The combustor 23 is configured such that a powdered mixed fuel is introduced from the container 10 together with nitrogen for transport. The combustor 23 is supplied with oxygen from the air separation device 8. Similar to the combustor 23, the reductor 24 is configured such that a powdered mixed fuel is introduced together with nitrogen for transport.

  In the combustor 23, a part of the mixed fuel is combusted by oxygen supplied from the air separation device 8, and the rest releases volatile components (carbon monoxide, water, etc.) by thermal decomposition. Moreover, the ash produced by the combustion of the mixed fuel in the combustor 23 is discharged to the slag hopper 21 as molten slag and collected.

  In the reductor 24, the mixed fuel charged from the container 10 is dry-distilled with the high-temperature gas from the combustor 23 to release volatile components. The mixed fuel particles (char) from which volatile components have been released react with water by a high-temperature gas and are gasified into a gasification gas such as carbon monoxide or hydrogen.

  The gasified gas obtained by the gasification is sent to a heat exchanger (not shown) and cooled to a predetermined temperature, and then sent to the char recovery device 22. The char recovery device 22 is a device that recovers the char discharged together with the gasification gas. The collected char is supplied to the combustor 23. Thereby, unburned carbon contained in the recovered char can be used for combustion in the combustor 23. The gasified gas from which the char has been removed in this way is sent to the gas purification facility 4.

  In the present embodiment, the char collection device 22 is provided. However, the present invention is not limited to such a mode. That is, the char collection device 22 may not be provided, and the collected char may not be supplied to the combustor 23.

  The gasification gas produced by the gasification facility 3 described above is required to have a sufficient amount of heat to operate the gas turbine 5. Further, the mixed fuel as a raw material for producing the gasified gas is required to suppress the melting temperature of the ash in the combustor 23 as much as possible. And it is preferable that many fuel sludge processed materials which are comparatively cheap are used for the mixed fuel.

  The ratio of the biomass and the sludge treatment product is obtained and mixed so as to be a mixed fuel that satisfies such conditions. Hereinafter, the manufacturing method of the mixed fuel which satisfy | fills the conditions mentioned above is demonstrated in detail.

  Here, as an example, the mixing ratio is obtained using a general computer including input / output means such as a keyboard and a display, calculation means such as a CPU, and storage means such as a RAM and a hard disk. FIG. 3 is a flowchart showing the steps for obtaining the mixture ratio of the mixed fuel. Various information is input to and output from the computer, and the mixing ratio is obtained by causing the computer to execute each step shown in the flowchart.

First, the basic properties of the mixed fuel are obtained, and the melting point T _Am of the ash content of the mixed fuel is obtained (first step). Specifically, the basic properties of the biomass and sludge treatment product are input to the computer (step S1). The basic properties include those obtained by industrial analysis of biomass and sludge treated products, those obtained by elemental analysis, and those obtained by analyzing the ash composition. Table 1 shows items and methods obtained by industrial analysis, elemental analysis, and ash composition analysis.

  Using each analysis method described above, an analysis value of each analysis item is obtained for each of the biomass and the sludge treated product. Then, the analysis value is input to the computer.

  Next, the mixing ratio of the biomass and the sludge treatment product is set (step S2). Specifically, the mixing ratio is input to the computer. The mixing ratio set here is provisional. The calculator calculates each basic property of the mixed fuel of the mixing ratio. For example, if the mixing ratio of biomass is X (0 <X <1), the mixing ratio of the sludge treatment product is 1-X, and the basic properties of the analysis items with biomass and sludge treatment product are A and B, respectively, the mixing The basic property of the analysis item of fuel is AX + (1-X) Y. By performing this for all analysis items, the basic properties of the mixed fuel can be obtained. In addition, in the case of using a plurality of types of biomass and a plurality of types of sludge treatment products, the basic properties of the mixed fuel can be calculated by setting the mixing ratio for each.

Next, the melting point T _Am of the ash content of the mixed fuel having the analysis value which is the calculation result described above is calculated (step S3). This melting point T _Am can be obtained by thermodynamic equilibrium calculation based on the ash composition of the mixed fuel.

A specific calculation is performed by executing a program (for example, FactSage manufactured by Computational Mechanics Research Center, Inc.) using a computer with a basic property of the mixed fuel as a parameter and implementing thermodynamic equilibrium calculation. This calculation, the melting point T _Am of the mixed fuel mixing ratio described above is obtained.

Next, the combustor temperature T _g (corresponding to the in-furnace temperature in the claims) of the combustor 23 is obtained by combustion calculation for each oxygen ratio in the combustor 23 and the calorific value of the gasification gas is calculated (second step). .

The combustor temperature T _g (corresponding to the in-furnace temperature in the claims) is the temperature inside the combustor 23 when the mixed fuel is combusted. The oxygen ratio is the ratio of the amount of oxygen in the gas charged into the combustor 23 to the theoretical combustion oxygen amount of the fuel charged into the gasifier 20.

First, compute the combustor temperature _{T g} (step S4). Specifically, the basic properties and the oxygen ratio of the mixed fuel obtained in the first step as a parameter, the combustor temperature T _g of the when the mixed fuel is combusted in combustor 23 determined by the combustion calculation. This combustion calculation is performed by appropriately setting a plurality of oxygen ratios.

Figure 4 is a graph conceptually showing the calculation results of the combustor temperature T _g by combustion calculations. The horizontal axis is the oxygen ratio and the vertical axis represents the combustor temperature T _g. Characteristics _L 1 ~L ₆ 0% biomass, 20%, 40%, 60%, 80%, 100%, the sludge workpiece 100%, 80%, 60%, 40%, 20%, 0% it represents the relationship between the combustor temperature T _g and the oxygen ratio for a mixture in a mixing ratio.

As shown, 20% biomass, when burned calculated for sludge mixture was 80% sludge processed, the calculation result as a characteristic L ₂ is obtained. As will be described later, when the combustion calculation is performed while changing the mixing ratio, calculation results such as characteristics L _{1 to} L ₆ are obtained. Any characteristic _L 1 ~L _6, combustor temperature The _{T g} seen to be proportional to oxygen ratio. Moreover, even with the same oxygen ratio, it can be seen high combustor temperature T _g as those often proportion of the biomass. In addition, the dotted line in a figure represents melting | fusing point _TAm + 100 degreeC (henceforth, determination temperature) of the ash content of mixed fuel. This will be described later.

  Next, the calorific value of the gasification gas is calculated (step S5). The calorific value can be obtained by combustion calculation from the composition and amount of the gasification gas burned in the combustor 23 and the gasification furnace input air amount obtained from the oxygen ratio.

FIG. 5 is a graph conceptually showing the calculation result of the calorific value of the gasification gas obtained by the combustion calculation. The horizontal axis represents the oxygen ratio, and the vertical axis represents the calorific value of the gasification gas. Characteristics L _{1 to} L ₆ represent the relationship between the calorific value and the oxygen ratio when gasified gas is generated from the same mixed fuel as shown in FIG.

As shown, 20% biomass, when burned calculated for sludge mixture was 80% sludge processed, the calculation result as a characteristic L ₂ is obtained. As will be described later, when the combustion calculation is performed while changing the mixing ratio, calculation results such as characteristics L _{1 to} L ₆ are obtained. It can be seen that in any of the characteristics L _{1 to} L ₆ , the calorific value is decreased against the oxygen ratio. Moreover, even if it is the same oxygen ratio, it turns out that the calorific value is so high that the ratio of biomass is large.

Next, it is determined whether the combustor temperature T _g and the heat generation amount satisfy predetermined conditions (third step).

Specifically, combustor temperature T _g is equal to or a melting point T _Am or more ash, and,
It is determined whether the calorific _value satisfies the amount of heat necessary for operating the gas turbine 5 (hereinafter referred to as the necessary amount of heat H ₀ ) (step S6).

Here, combustor temperature _{T g} is the melting point _{T Am} + 100 ° C. or higher (hereinafter, the melting point _{T Am} + 100 ° C. referred to as determination temperature) determines whether a. If the combustor temperature T _g is determined temperature or higher, combustor temperature The T _g, ash content mixed fuel occurs with combustion means that a temperature sufficient to melt.

Incidentally, in theory, since combustor temperature T _g is melted ash is higher than the melting point T _Am, combustor temperature The T _g may determine whether or not greater than the melting point T _Am. The reason why the determination temperature obtained by adding 100 ° C. to the melting point T _Am is used for empirical reasons, because the ash can be more reliably melted and discharged from the combustor 23.

Further, the required heat quantity H ₀ is determined by the specifications or actual measurement of the gas turbine 5.

In the example shown in FIG. 4, when the combustion calculation is performed for a sludge mixture having a biomass of 20% and a sludge treatment product of 80%, the oxygen ratio is R ₂ or more (hereinafter, oxygen ratio range A) as shown in the characteristic L _2. it can be seen that the combustor temperature the T _g is higher than the determination temperature, if any. As will be described later, when the combustion calculation is performed while changing the mixing ratio, the calculation results are also obtained for the characteristics L _{1 to} L ₆ . Mixed fuel mixing ratio on the characteristics _L 3 ~L ₅ is combustor temperature _{T g} is shown that above a determined temperature if the oxygen ratio is _R 3 to R ₅ above. The characteristics L ₁ and L ₆ are not mixed fuel, but the same can be said.

On the other hand, in the example shown in FIG. 5, when the oxygen ratio when the characteristic L ₂ and the required heat quantity H ₀ intersect is R _X , the mixed fuel of the characteristic L ₂ has an oxygen ratio greater than 0 and less than or equal to R _x (hereinafter referred to as “ _X”). , it can be seen that oxygen ratio range B) heat requirements H ₀ or more heating value if.

Therefore, for the mixed fuel having the mixing ratio of the characteristic L _2, a heat quantity equal to or greater than the necessary heat quantity H ₀ can be obtained as long as it is in a range satisfying both the oxygen ratio range A and the oxygen ratio range B and not less than R _{2 and} R _x. together, the calculation result is obtained that the combustor temperature T _g is equal to or higher than the determination temperature.

In this way, it is combustor temperature T _g is determined temperature or higher, and if the heating value satisfies the condition that it is necessary heat quantity H ₀ above (step S6: Yes), and the oxygen ratio mixed fuel of the mixture ratio Are recorded (step S7). Then, as a fourth step, if there are different mixing ratios of yet uncalculated (step S8: Yes), setting the mixing ratio among them (e.g., mixing ratio of characteristic _{L 1, L} 3 ~L ₆₎ Then, the first to third steps (steps S2 to S7) are executed. When the above conditions are not satisfied (step S6: No), the first to third steps (steps S2 to S7) are executed by setting different uncalculated mixing ratios.

By repeating the first step to the third step while changing the mixing ratio in this way, it is determined whether or not the above-described conditions are satisfied for the mixed fuels having the different characteristics L ₁ and L _{3 to} L _6. .

For example, for the characteristic L ₃ , if the mixing ratio of biomass 40% sewage sludge 60% and the oxygen ratio R ₃ or more and R _y or less are output as a result satisfying the above condition.

The mixed fuel characteristics L _4, from FIG. 4, the oxygen ratio is even combustor temperature T _g if R ₃ or more satisfies a determination temperature, from 5, calorific value and the oxygen ratio is R ₃ or Calculated as not satisfying required heat. That is, a mixed fuel of characteristics L ₄ are the result that it is unsuitable to obtain.

When there is no uncalculated mixture ratio (step S8: No), the one with the highest ratio of the sludge treatment product is selected from the mixture ratios of the mixed fuel satisfying the above conditions (step S9). In the example of FIGS. 4 and 5, the mixed fuel having the characteristic L ₂ mixing ratio is selected (however, the oxygen ratio is not less than R _{2 and not} more than R _x ).

A mixed fuel can be produced by mixing the biomass and the sludge-treated product at the mixing ratio (characteristic L ₂ ) thus obtained. By selecting the one having the highest ratio of the sludge treatment product, the cheapest mixed fuel can be produced. In addition, if the said conditions are satisfy | filled, it is not necessary to employ | adopt the mixing ratio with which the ratio of sludge processed material is high. In the example of FIG. 4 and FIG. 5, it may be selected mixing fuel mixing ratio of the characteristic L ₃ (provided that the oxygen ratio is less R ₃ or R _y).

  According to the mixed fuel manufacturing method described above, the fuel used for the gasification power generation facility 1 including the spouted bed type gasification furnace 20 and the gas turbine 5 has the amount of heat necessary to operate the gas turbine 5. Gasified gas can be generated, and a mixed fuel having a combustor temperature sufficient to melt the ash in the combustor 23 can be produced.

  Since the mixed fuel contains a sludge treatment product in addition to biomass, the cost per unit weight is lower than that of the biomass alone. The mixed fuel satisfies the requirement that the gasification power generation facility 1 that can prevent the defective discharge of ash in the combustor 23 and can operate the gas turbine 5 can be smoothly operated. .

  In particular, sludge treated products are difficult to obtain a stable mixed fuel because of the large variation in their basic properties. However, if the basic properties are obtained by the above-described manufacturing method, a suitable mixed fuel for the gasification power generation facility 1 is obtained. It can be obtained quickly.

  Furthermore, the use of the mixed fuel is expected to be promoted because the price can be kept low by using the mixed fuel. For this reason, the usage-amount of the biomass provided to mixed fuel also increases, and the effective utilization of biomass can be promoted.

  The mixed fuel produced as described above is supplied to the carbonizer 11 as shown in FIG. 2, converted into volatile gas and carbide, and then supplied to the gasifier 20. Then, the mixed fuel is gasified with the oxygen ratio of the combustor 23 of the gasification furnace 20 set to that obtained by the above-described calculation.

  By supplying the mixed fuel to the gasification power generation facility 1 and operating the gas turbine 5 in this way, the gas turbine 5 can be operated while using an inexpensive mixed fuel, and the ash is melted in the combustor 23 to externally. Can be discharged reliably.

  In addition, you may convey mixed fuel to the gasification power generation equipment 1 in the position away from the place where it manufactured. In this case, the mixed fuel is preferably in a solid form such as a pellet form or a briquette form. When the mixed fuel is made into a solid state, the mixed fuel has a high density. Therefore, the mixed fuel becomes easy to handle during transportation and is suitable for mass transportation.

<Embodiment 2>
The gasification power generation facility according to Embodiment 1 does not manufacture the mixed fuel itself, but may be an integrated gasification power generation facility including the manufacture of the mixed fuel. FIG. 6 is a schematic configuration diagram of a gasification power generation facility that is an example of a plant according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same thing as Embodiment 1, and the overlapping description is abbreviate | omitted.

  As shown in the figure, the gasification power generation facility 30 includes a mixed fuel production device 9. The mixed fuel production apparatus 9 is an apparatus for producing a mixed fuel by supplying biomass and sludge treated products as raw materials and mixing them at a predetermined mixing ratio. The manufactured mixed fuel is supplied to a carbonizer (not shown) as in the first embodiment, and is supplied to the gasification facility 3 as volatile gas or carbide.

  In the mixed fuel manufacturing apparatus 9, the mixing ratio calculated by the manufacturing method described in the first embodiment is set, and the biomass and the sludge treatment product are mixed at the mixing ratio. The mixed fuel manufacturing apparatus 9 itself has a calculation function for executing each step of the manufacturing method described in the first embodiment, and the mixed fuel is manufactured based on the mixing ratio obtained by the calculation. May be.

  Then, in the gasification facility 3 of the gasification power generation facility 30, the mixed fuel is gasified in a state where the inside of the combustor is at the oxygen ratio obtained by the above manufacturing method.

  In such a gasification power generation facility 30, as in the first embodiment, the gas turbine 5 can be operated while using an inexpensive mixed fuel, and the ash is melted in the combustor 23 so as to be reliably externally provided. Can be discharged.

<Other embodiments>
Although Embodiment 1 and Embodiment 2 demonstrated gasification power generation equipment as an example of a plant, it is not limited to this. For example, it is not necessary to install the exhaust heat recovery boiler 6 and the steam turbine 7, and a gas engine or a diesel engine may be used instead of the gas turbine.

  Moreover, although the mixed fuel was decomposed | disassembled by the carbonizer 11 and supplied to the gasification furnace 20, it is not limited to this. Depending on the properties of the mixed fuel, the mixed fuel may be supplied directly to the gasification furnace 20.

  The present invention can be used in a power generation system that generates biomass gasification gas from biomass and uses the biomass gasification gas as fuel.

DESCRIPTION OF SYMBOLS 1, 30 Gasification power generation equipment 3 Gasification equipment 4 Gas purification equipment 5 Gas turbine 6 Waste heat recovery boiler 7 Steam turbine 8 Air separation device 9 Mixed fuel production device 10 Container 11 Carbonizer 20 Gasification furnace 21 Slag hopper 22 Char recovery device 23 Combustor 24 Reductor

Claims (5)

Operation of a plant comprising an entrained bed gasification furnace that produces gasification gas from mixed fuel and oxygen mixed with biomass and sludge treatment product obtained by treating sewage sludge, and an internal combustion engine that obtains power using the gasification gas as fuel A method,
A first step of obtaining a melting point T _Am of the ash content of the mixed fuel by thermodynamic equilibrium calculation based on an ash content composition of the mixed fuel obtained by mixing the biomass and the sludge treatment product at a predetermined mixing ratio ;
The temperature when the mixed fuel is burned at a predetermined oxygen ratio is obtained by combustion calculation, and the temperature is set as the in-furnace temperature Tg of the spouted bed gasifier, and is generated when the mixed fuel is burned at a predetermined oxygen ratio. A second step of obtaining the calorific value of the gasification gas by combustion calculation;
A third step of obtaining an oxygen ratio that satisfies the condition that the furnace temperature Tg is equal to or higher than the melting point T _Am and the calorific value allows the internal combustion engine to be operated;
The oxygen ratio is obtained by executing the first step to the third step for each of a plurality of different mixing ratios, the mixed fuel having a mixing ratio selected from the plurality of different mixing ratios, and corresponding to the mixing ratio And a fourth step of supplying an amount of oxygen corresponding to an oxygen ratio to the spouted bed gasifier . A method for operating a plant according to claim 1 ,
In the fourth step, the oxygen ratio is determined by executing the first step to the third step for a plurality of different mixing ratios , and the mixed fuel having the highest ratio of the sludge treated product, and the mixed fuel An operation method of a plant, characterized in that an amount of oxygen corresponding to an oxygen ratio corresponding to a mixing ratio is supplied to the spouted bed gasifier . In the operation method of the plant according to claim 1 or 2 ,
The method for operating a plant, wherein the internal combustion engine is at least one of a gas turbine, a gas engine, and a diesel engine. A mixed fuel for a plant comprising a spouted bed gasification furnace for producing gasified gas by gasifying a mixed fuel obtained by mixing biomass and a sludge treatment product obtained by treating sewage sludge, and an internal combustion engine for burning the gasified gas A manufacturing method of
A first step of obtaining the melting point T _Am ash of the mixed fuel by thermodynamic equilibrium calculation based on the ash content the composition of the mixed fuel prepared by mixing the biomass and the sludge treated in a predetermined mixing ratio,
The temperature when the mixed fuel is burned at a predetermined oxygen ratio is obtained by combustion calculation, and the temperature is set as the in-furnace temperature Tg of the spouted bed gasifier, and is generated when the mixed fuel is burned at a predetermined oxygen ratio. A second step of obtaining the calorific value of the gasification gas by combustion calculation ;
A third step of determining the oxygen ratio satisfying the condition that the furnace temperature Tg becomes higher the melting point T _Am, and the amount of generated heat is possible operate the internal combustion engine,
The oxygen ratio is determined by executing the first to third steps for each of a plurality of different mixing ratios, and the mixed fuel having a mixing ratio selected from the plurality of different mixing ratios is treated with the biomass and the sludge treatment product. And a fourth step of producing the mixed fuel. A mixed fuel production apparatus for producing a mixed fuel by mixing biomass and a sludge treatment product obtained by treating sewage sludge,
A spouted bed gasifier for gasifying the mixed fuel to produce gasified gas;
A plant comprising an internal combustion engine for obtaining power by burning the gasified gas,
The mixed fuel production apparatus comprises:
Calculated melting point T _Am ash of the mixed fuel by thermodynamic equilibrium calculation based on the ash content the composition of the mixed fuel prepared by mixing the biomass and the sludge treated in a predetermined mixing ratio,
The temperature when the mixed fuel is burned at a predetermined oxygen ratio is obtained by combustion calculation, and the temperature is set as the in-furnace temperature Tg of the spouted bed gasifier, and is generated when the mixed fuel is burned at a predetermined oxygen ratio. Obtain the calorific value of the gasification gas by combustion calculation,
The furnace temperature Tg becomes higher the melting point T _Am, and the amount of generated heat calculated oxygen ratio that satisfies the condition that it can operate the internal combustion engine, the mixed fuel of the selected mixture ratio of a plurality of different said mixing ratio From the biomass and the sludge treatment product,
The spouted bed gasification furnace gasifies the mixed fuel supplied from the mixed fuel manufacturing apparatus at the oxygen ratio determined by the mixed fuel manufacturing apparatus .

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