JP5990505B2 - Production method of ashless coal - Google Patents

Description

  The present invention relates to a method for producing ashless coal for obtaining ashless coal from which ash is removed from coal.

  As a manufacturing method of ashless coal, there exists a thing described in patent documents 1, for example. In Patent Literature 1, a slurry is prepared by mixing coal and a solvent, and the resulting slurry is heated to extract a coal component soluble in the solvent, and soluble in the solvent from the slurry from which the coal component is extracted. A method for producing ashless coal is described in which a solution containing various coal components is separated, and then a solvent is recovered from the separated solution to obtain ashless coal.

Japanese Patent No. 4045229

  In the process of producing ashless coal, coal in a state such as slurry and solvent are heated in many steps. That is, thermal energy is given to coal and a solvent. This thermal energy (heating energy) is introduced from outside the process system in the form of high-pressure steam, low-pressure steam, electricity, or the like.

  Here, the exhaust heat generated in the process where the heat energy is introduced is not discarded as it is, but if it is used in any of the processes for producing ashless coal, the heat energy newly introduced from outside the process system (heating) Energy), and as a result, it is considered that the production cost of ashless coal (running cost of ashless coal production equipment) can be reduced as compared with the conventional case. However, the exhaust heat generated in any of the processes where heat energy is introduced cannot be effectively utilized to the extent that it contributes to the reduction of the production cost of ashless coal. In a process where the temperature of the exhaust heat generated is too low or the amount of heat generated is too small, even if the exhaust heat generated in that process is used in another process, the slurry is effectively heated. It is not possible. That is, exhaust heat cannot be used to the extent that it contributes to a reduction in the production cost of ashless coal. In this way, the ashless coal production cost cannot be reduced in the facility on the scale of implementation simply by using the exhaust heat generated in the process of introducing thermal energy.

  In addition, if the method for extracting the exhaust heat generated in the process in which the thermal energy is introduced is not a simple method, it does not contribute to a reduction in the production cost of ashless coal. This is because if the method for extracting the exhaust heat is complicated, the amount of equipment becomes complicated and the introduction cost of the equipment increases, and the labor cost of the operation may increase.

  This invention is made | formed in view of the said situation, Comprising: The objective was provided with the process of utilization of waste heat which can reduce the manufacturing cost of ashless coal (running cost of ashless coal manufacturing equipment). It is to provide a method for producing ashless coal.

  The present invention includes a slurry preparation step of preparing a slurry by mixing coal and a solvent, an extraction step of extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step, In the separation step, the slurry obtained in the extraction step is separated into a solution containing a coal component that is soluble in the solvent and a solid content concentrate in which the coal component that is insoluble in the solvent is concentrated. An ashless coal obtaining step of obtaining ashless coal by evaporating and separating the solvent from the separated solution. In this ashless coal production method, the heat energy held by the solvent in the vapor state generated in the extraction step and / or the ashless coal acquisition step is used as a heat source in at least one step of producing the ashless coal. And / or heat recovery with a waste heat recovery boiler as heat energy possessed by water vapor.

  According to the present invention, the thermal energy generated in the process of producing ashless coal can be effectively used for the production of ashless coal in an effective and simple manner. As a result, the production cost of ashless coal ( The running cost of ashless coal production equipment can be reduced.

It is a block diagram which shows the ashless coal manufacturing equipment for demonstrating the manufacturing method of the ashless coal which concerns on 1st Embodiment of this invention. It is a block diagram which shows the ashless coal manufacturing equipment for demonstrating the manufacturing method of the ashless coal which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the ashless coal manufacturing equipment for demonstrating the manufacturing method of the ashless coal which concerns on 3rd Embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the ashless coal production facility 100 includes a coal hopper 1, a solvent tank 2, a slurry preparation tank 3, a transfer pump 4, a dehydration tank 5, in order from the upstream side of the ashless coal (HPC) production process. A transfer pump 6, a preheater 7, an extraction tank 8, a first gravity settling tank 9, a second gravity settling tank 10, and flashers (solvent separators) 11 and 12 are provided.

  Moreover, as a series of apparatuses for effectively using the thermal energy generated in the extraction tank 8, the ashless coal production facility 100 includes a high temperature recovery solvent tank 15, a transfer pump 16, a first heat exchanger 17, and exhaust heat recovery. A boiler 18 is provided.

  In addition, as a series of devices for effectively using the thermal energy generated in the flasher 11 (solvent separator for ashless coal), the ashless coal production facility 100 includes a second heat exchanger 13 and heating for slurry dehydration. A container 14 is provided.

  Furthermore, the ashless coal production facility 100 includes an exhaust heat recovery boiler 19 as an apparatus for effectively using the thermal energy generated in the flasher 12 (solvent separator for by-product coal).

  Here, the manufacturing method of ashless coal has a slurry preparation process, a slurry dehydration process, an extraction process, a separation process, an ashless coal acquisition process, and a byproduct charcoal acquisition process. Hereinafter, each of these steps will be described. Moreover, the effective use of the thermal energy generated in the production process of ashless coal will be described while explaining each of these steps.

  In addition, there is no restriction | limiting in particular in the coal used as a raw material in this manufacturing method, Bituminous coal with a high extraction rate (ratio of the soluble component of coal extracted to a solvent) may be used as a raw material, and cheaper inferior quality coal (sub- (Bituminous coal, lignite) may be used as a raw material. The ashless coal means ash content of 5% by weight or less, preferably 3% by weight or less.

<Slurry preparation process>
The slurry preparation step is a step of preparing a slurry by mixing coal and a solvent. The slurry preparation step is performed in the slurry preparation tank 3 in FIG. Coal as a raw material is charged into the slurry preparation tank 3 from the coal hopper 1, and a solvent is charged into the slurry preparation tank 3 from the solvent tank 2. The coal and solvent charged into the slurry preparation tank 3 are mixed by the stirrer 3a to become a slurry composed of coal and solvent.

  The mixing ratio of coal with respect to the solvent is, for example, 0.5 to 4.0 on a dry coal basis, and more preferably 0.75 to 2.0.

<Slurry dewatering process>
The slurry dewatering step is a step of dehydrating the slurry by preheating the slurry obtained (prepared) in the slurry preparing step. The slurry dewatering step is performed in the dewatering tank 5 in FIG. The slurry prepared in the slurry preparation tank 3 is supplied to the dehydration tank 5 by the transfer pump 4. The slurry supplied to the dewatering tank 5 is mixed by the stirrer 5a while being heated by the heated slurry sent from the slurry dewatering heater 14. Thereby, the water | moisture content contained in a slurry evaporates and the water content in a slurry reduces. The slurry in the dehydration tank 5 is pulled out from the bottom of the dehydration tank 5 by the transfer pump 6 and then returned to the dehydration tank 5 from the upper part of the dehydration tank 5 via the slurry dehydration heater 14.

  Slurry is generated in the flasher 11 within the heater 14 for slurry dehydration, and is heated by the thermal energy held by the solvent in the vapor state sent via the pipe 21. Therefore, the thermal energy for slurry dehydration newly introduced from outside the process system can be reduced.

  The dehydration temperature of the slurry in the slurry dehydration step is a temperature not lower than the boiling point of water and lower than the boiling point of the solvent, and is, for example, 100 to 150 ° C.

  Note that the slurry dewatering step may be omitted when the amount of water contained in the raw coal is small. When the slurry dewatering step is omitted, the slurry prepared in the slurry preparing step is directly sent to the next extraction step (see, for example, FIG. 2 in which the dewatering tank 5 is not provided).

<Extraction process>
The extraction step is a step of heating the slurry dehydrated in the slurry dehydration step to extract a coal component soluble in the solvent (dissolve in the solvent). The extraction process is performed in the preheater 7 and the extraction tank 8 in FIG. The slurry dehydrated in the dehydration tank 5 is supplied to the preheater 7 by the transfer pump 6 and heated to a predetermined temperature, then supplied to the extraction tank 8, and held at the predetermined temperature while being stirred by the stirrer 8a. Extraction is performed.

  Here, in this embodiment, the slurry dehydrated in the dehydration tank 5 is supplied to the preheater 7 by the transfer pump 6 via the second heat exchanger 13. Slurry is generated in the second heat exchanger 13 by the flasher 11 and is heated by the thermal energy held by the solvent in the vapor state sent via the pipe 21. Therefore, the heat capacity of the preheater 7 can be made smaller than before. In other words, the heat energy newly introduced from outside the process system (heating energy) can be reduced.

  On the other hand, the solvent in the vapor state generated in the extraction tank 8 is extracted from the top of the extraction tank 8, flows in the pipe 22, and in the order of the first heat exchanger 17 and the exhaust heat recovery boiler 18. To be supplied. The effective use of thermal energy in the first heat exchanger 17 will be described later. The heat energy generated in the extraction tank 8 and remaining after passing through the first heat exchanger 17 is recovered by the exhaust heat recovery boiler 18 as the heat energy of the water vapor.

  Water vapor (recovered thermal energy) generated in the exhaust heat recovery boiler 18 can be used as steam in each step of producing ashless coal. Therefore, the amount of steam newly introduced from outside the process system can be reduced. In addition, the solvent which came out of the exhaust heat recovery boiler 18 is circulated and used by returning to the slurry preparation tank 3 (slurry preparation process). The circulation of this solvent is the same in the exhaust heat recovery boiler 19.

  Touch about the solvent. When extracting coal components that are soluble in the solvent by heating the slurry obtained by mixing coal and solvent, a solvent with a large dissolving power for coal, often an aromatic solvent (hydrogen donating property) Alternatively, a non-hydrogen-donating solvent) and coal are mixed and heated to extract organic components in the coal.

  The non-hydrogen donating solvent is a coal derivative which is a solvent mainly composed of a bicyclic aromatic and purified mainly from a coal carbonization product. Main components of the non-hydrogen donating solvent include bicyclic aromatic naphthalene, methyl naphthalene, dimethyl naphthalene, trimethyl naphthalene and the like, and other non-hydrogen donating solvent components have aliphatic side chains. Naphthalenes, anthracenes, fluorenes, and these include biphenyl and alkylbenzenes having long aliphatic side chains. A hydrogen donating compound (including coal liquefied oil) typified by tetralin may be used as a solvent.

  Further, the boiling point of the solvent is not particularly limited. From the viewpoints of pressure reduction in the extraction step and separation step, extraction rate in the extraction step, and the like, for example, a solvent having a boiling point of 180 to 300 ° C., particularly 240 to 280 ° C. is preferably used.

  The heating temperature of the slurry in the extraction step is not particularly limited as long as the solvent-soluble component can be dissolved, and is, for example, 300 to 420 ° C. from the viewpoint of sufficient dissolution of the solvent-soluble component and improvement of the extraction rate. More preferably, it is 360-400 degreeC.

  The extraction process is performed in the presence of an inert gas such as nitrogen. The pressure in the extraction tank 8 is preferably 1.0 to 2.0 MPa, although it depends on the temperature at the time of extraction and the vapor pressure of the solvent used. When the pressure in the extraction tank 8 is lower than the vapor pressure of the solvent, the solvent volatilizes and is not confined in the liquid phase, so that extraction cannot be performed. In order to confine the solvent in the liquid phase, a pressure higher than the vapor pressure of the solvent is required.

<Separation process>
In the separation step, the slurry obtained in the extraction step is subjected to, for example, a gravity sedimentation method, a solution containing a coal component soluble in a solvent, and a solid concentrate (solvent insoluble component concentrate) in which a coal component insoluble in a solvent is concentrated. ). This separation step is performed in the first gravity settling tank 9 and the second gravity settling tank 10 in FIG. The slurry obtained in the extraction step is separated into a supernatant liquid as a solution and a solid concentrate in the first gravity settling tank 9 and the second gravity settling tank 10 by gravity. The supernatant liquids in the upper parts of the gravity sedimentation tanks 9 and 10 are respectively sent to the flasher 11. The solid concentration liquid settled in the lower part of the second gravity settling tank 10 is sent to the flasher 12. In the present embodiment, the gravity settling tank has two stages (multiple stages), but may have one stage as shown in FIG. In addition, it is ideal that the supernatant liquid and the solid concentration liquid are completely separated, but there are cases where the solid content is mixed in a part of the finished liquid or the supernatant liquid is mixed in a part of the solid content. is there.

  The gravitational sedimentation method is a method in which a slurry is retained in a tank to sediment and separate solvent-insoluble components using gravity. As a method for separating the solution containing the coal component dissolved in the solvent from the slurry obtained in the extraction step, there are a filtration method, a centrifugal separation method and the like in addition to the gravity sedimentation method.

  The gravity sedimentation tanks 9 and 10 are preferably kept warm, heated or pressurized in order to prevent reprecipitation of solvent-soluble components eluted from coal. The heating temperature is, for example, 300 to 380 ° C., and the tank internal pressure is, for example, 1.0 to 3.0 MPa.

  Here, in this embodiment, the inside of the second gravity settling tank 10 is kept warm (heated) using the thermal energy possessed by the solvent in the vapor state generated in the extraction tank 8. The solvent accumulated in the high temperature recovery solvent tank 15 flows through the first heat exchanger 17 by the transfer pump 16 and then is supplied to the second gravity settling tank 10. In the first heat exchanger 17, the solvent is generated in the extraction tank 8 and is heated with the thermal energy held by the vapor-state solvent sent via the pipe 22. By supplying the heated solvent to the second gravity settling tank 10, the inside of the second gravity settling tank 10 is kept warm (heated). According to this configuration, since the inside of the second gravity settling tank 10 is kept warm (heated), the heat energy newly introduced from outside the process system can be reduced.

<Ashless coal acquisition process>
The ashless coal acquisition step is a step of obtaining ashless coal by evaporating and separating the solvent from the solution (supernatant liquid) separated in the separation step described above. This ashless coal acquisition step is performed by the flasher 11 in FIG. The solution separated in the gravity settling tanks 9 and 10 is supplied to the flasher 11, and the solvent is evaporated and separated from the supernatant in the flasher 11.

  The tank internal pressure of the flasher 11 is, for example, 0.1 MPa (normal pressure). Therefore, the solution separated in the gravity sedimentation tanks 9 and 10 is ejected into the flasher 11, and the solvent in the solution is evaporated and separated from the solution (flash distillation method). Thereby, ashless coal substantially free of ash (for example, having an ash content of 3% by weight or less) is obtained.

  The method for separating the solvent from the solution (supernatant) is not limited to the flash distillation method. Examples of other separation methods include thin film distillation. The thin film distillation method is a method in which a distillation object (in the present invention, a solution separated in a separation step) is introduced into a tank (thin film distillation tank) containing a scraper (also called a wiper), and the scraper is used to distill on the inner wall of the tank. This is a distillation method in which a target thin film is formed and continuous distillation is performed. The inner wall of the tank is heated from the outside. The pressure in the tank (thin film distillation tank) is, for example, 0.1 MPa (normal pressure).

  On the other hand, the vaporized solvent separated from the solution is withdrawn from the top of the flasher 11, flows through the pipe 21, and passes through the second heat exchanger 13 and the slurry dewatering heater 14 in this order. Supplied. The solvent exiting the slurry dehydrating heater 14 enters the high temperature recovery solvent tank 15.

<By-product coal acquisition process>
The byproduct charcoal acquisition step is a step of obtaining byproduct charcoal by evaporating and separating the solvent from the solid content concentrate separated in the separation step. This byproduct charcoal acquisition step is performed by the flasher 12 in FIG. The solid concentrate separated in the second gravity sedimentation tank 10 is supplied to the flasher 12, and the solvent is evaporated and separated from the solid concentrate in the flasher 12 (flash distillation). In addition, a byproduct charcoal acquisition process is not an essential process.

  The pressure in the tank of the flasher 12 is, for example, 0.1 MPa (normal pressure), similar to the flasher 11 for ashless coal. The method for separating the solvent from the solid concentrate is not limited to the flash distillation method. By separating the solvent, by-product charcoal (also referred to as RC or residual charcoal) in which solvent-insoluble components including ash and the like are concentrated can be obtained from the solid concentrate.

  Here, in this embodiment, the heat energy possessed by the solvent in the vapor state generated by the flasher 12 is recovered by the exhaust heat recovery boiler 19 as the heat energy possessed by the water vapor. The vapor-state solvent separated from the solid concentrate is extracted from the top of the flasher 12 and supplied to the exhaust heat recovery boiler 19. Water vapor (recovered thermal energy) generated in the exhaust heat recovery boiler 19 can be used as steam in each process of producing ashless coal. Therefore, the amount of steam newly introduced from outside the process system can be reduced.

<Thermal energy generated in the ashless coal manufacturing process>
Table 1 summarizes examples of heat energy that can be used effectively in the ashless coal production process. As can be seen from Table 1, the temperature of the thermal energy generated in the extraction process (extraction tank 8) is a high temperature of 400 ° C. at the maximum. Moreover, although the temperature of the heat energy generated in the ashless coal acquisition process (in the case of the flasher 11) is about 270 ° C. at the maximum, it is lower than the temperature of the heat energy generated in the extraction process (the extraction tank 8), 1.08 MMkcal / ton-coal throughput is large. “/ Ton-coal processing amount” means that 1 ton of coal is processed. In Table 1, the generation device is a flasher in the ashless coal acquisition step, as illustrated in FIG. 1, when the flasher 11 (flash distillation method) is used in the ashless coal acquisition step. In the ashless charcoal acquisition process, the generator is a thin film distillation tank means that a thin film distillation tank (thin film distillation method) is used in the ashless charcoal acquisition process (the same applies to Table 2).

<Use of heat energy>
Table 2 shows an example of the use destination of the thermal energy shown in Table 1 generated in the ashless coal manufacturing process.

  As shown in Table 1, the temperature of the heat energy generated in the extraction process (extraction tank 8) is a high temperature of 400 ° C. at the maximum, so as shown in Table 2, in the extraction process (extraction tank 8). The generated thermal energy can be applied as a heating source in various processes such as a slurry dehydration process, an extraction process, a separation process, and a steam recovery process.

  On the other hand, the maximum temperature of heat energy generated by the flasher in the ashless coal acquisition process is about 270 ° C., which is lower than the temperature of heat energy generated in the extraction process (extraction tank 8). For this reason, the heat energy generated by the flasher in the ashless coal acquisition process is not suitable for heating an object to be heated to 300 ° C. or higher, but the heat amount is 1.08 MMkcal / ton-coal processing amount. Since it is large, it is suitable for heating across multiple devices.

  In contrast, when a thin film distillation tank (thin film distillation method) is used in the ashless coal acquisition process, the maximum temperature of the heat energy generated from the tank is 300 ° C., and the flasher (flash distillation) is used in the ashless coal acquisition process. Higher than when using However, the amount of heat generated from the thin-film distillation tank is not so large as 0.024 MMkcal / ton-coal processing amount, so it can be used as a heating source for heating the slurry in the slurry dehydration process or the extraction process. However, it is more suitable to use as a heating source for steam recovery.

  The calorie | heat amount of the heat energy which generate | occur | produces with the flasher of a byproduct coal acquisition process is 0.144 MMkcal / ton-coal process amount, and is larger than the calorie | heat amount of the heat energy which generate | occur | produces from a thin film distillation tank. Therefore, the thermal energy generated by the flasher in the byproduct coal acquisition process is not only suitable for use as a heating source for steam recovery, but also used as a heating source for heating the slurry in the slurry dehydration process or extraction process. Also suitable for that.

<Specific reduction in heat energy newly introduced from outside the process system>
In ashless coal production facility 100 illustrated in FIG. ^{1, 4.9 × 10 3 kcal /} ton- coal throughput in a slurry dewatering heater 14, in the first heat exchanger 17 3.7 × ¹⁰ 3 kcal / ton -Coal processing amount, 13.6x10 ³ kcal / ton-coal processing amount in the second heat exchanger 13 can be covered with thermal energy generated from the process (equipment) of ashless coal production. Moreover, the heat amount of 3.4 × 10 ³ kcal / ton-coal processing amount can be recovered by the exhaust heat recovery boiler 19 to produce steam.

<Action / Effect>
In the present invention, among the processes for producing ashless coal, the thermal energy possessed by the solvent in the vapor state generated in at least one of the extraction process and the ashless coal acquisition process is converted into ashless coal. It is used by performing either one of a heat source in at least one process to be manufactured and a heat recovery by a waste heat recovery boiler as heat energy possessed by water vapor.

  For example, in the ashless coal production facility 100 shown in FIG. 1, heat is also generated in the slurry dewatering step (dehydration tank 5) and the separation step (gravity settling tanks 9 and 10). However, the temperature of heat generated in these processes is low and the amount of heat is small. Compared with this, the temperature of the heat | fever which generate | occur | produces in an extraction process (extraction tank 8), an ashless coal acquisition process (for example, flasher 11), and a byproduct coal acquisition process (for example, flasher 12) is high. Even if the temperature of heat is not significantly high (which is higher than the temperature of heat generated in the slurry dehydration step and the separation step), the amount of heat is large. Therefore, the heat energy generated in these steps is used as a heat source in at least one step for producing ashless coal, and / or heat is recovered as heat energy possessed by water vapor in a waste heat recovery boiler, thereby Energy can be effectively used effectively in the production of ashless coal.

  In the present invention, the generated thermal energy is handled as the thermal energy held by the solvent in the vapor state. The solvent in the vapor state can be sent without difficulty by connecting the devices with piping. That is, the solvent in the vapor state is easy to handle.

  As described above, according to the present invention, the thermal energy generated in the process of producing ashless coal can be effectively used for the production of ashless coal in an effective and simple manner. Production cost (running cost of ashless coal production equipment) can be reduced.

  Here, in this embodiment, the thermal energy possessed by the solvent in the vapor state generated in the extraction step (extraction tank 8) is used as a heat source for solvent heating in the separation step (second gravity settling tank 10). Since the temperature of the thermal energy generated in the extraction step (extraction tank 8) is as high as 400 ° C. at the maximum, the gravity sedimentation tank can be effectively kept (heated) by the thermal energy.

  Moreover, in this embodiment, after using the heat energy which the solvent of the vapor | steam state generate | occur | produced in the extraction process (extraction tank 8) uses as a heat source for solvent heating in a separation process (2nd gravity sedimentation tank 10), it remains. The heat energy is recovered by the exhaust heat recovery boiler 18 as the heat energy of water vapor. According to this configuration, the remaining heat energy is recovered by the exhaust heat recovery boiler 18, so that waste heat that is wasted can be reduced as much as possible.

  In addition, by supplying the solvent in the vapor state generated in the extraction step (extraction tank 8) directly to the exhaust heat recovery boiler 18, almost all of the thermal energy possessed by the solvent in the vapor state is stored in the heat of water vapor. It is also preferable to recover heat as energy in the exhaust heat recovery boiler 18. Water vapor (recovered thermal energy) generated in the exhaust heat recovery boiler 18 can be used as low-pressure steam in each process of producing ashless coal. Therefore, the amount of low-pressure steam newly introduced from outside the process system can be reduced.

  Moreover, in this embodiment, the thermal energy which the solvent of the vapor | steam state generate | occur | produced in the ashless coal acquisition process (for example, flasher 11) is used as a heat source for the slurry heating in an extraction process (extraction tank 8) (the 1st) 2 heat exchanger 13). By using the thermal energy generated in the ashless coal acquisition process (for example, the flasher 11) as the energy for slurry heating, the heating amount of the slurry in the preheater 7 can be reduced. As a result, the heat energy newly introduced from outside the process system (heating energy) can be reduced.

  Moreover, in this embodiment, after using the thermal energy which the solvent of the vapor | steam state generate | occur | produced in the ashless coal acquisition process (for example, flasher 11) is used as a heat source for slurry heating in an extraction process (extraction tank 8), it remains. Thermal energy is used as a heat source for slurry dewatering in the slurry dewatering step (dewatering tank 5) (slurry dewatering heater 14). As shown in Table 1, since the amount of heat energy generated in the ashless coal acquisition process (flasher 11) is as large as, for example, 1.08 MMkcal / ton-coal processing amount, In addition, the slurry can be heated.

  Moreover, in this embodiment, the heat energy which the solvent of the vapor | steam state generate | occur | produced in the byproduct charcoal acquisition process (flasher 12) holds is heat-recovered by the exhaust heat recovery boiler 19 as heat energy which water vapor | steam has. Similarly to the case where the heat energy held by the solvent in the vapor state generated in the extraction step (extraction tank 8) is recovered by the exhaust heat recovery boiler 18 as the heat energy of the steam, according to this configuration, the exhaust heat recovery boiler is used. Since the steam generated in 19 (recovered thermal energy) can be used as steam in each process of producing ashless coal, the amount of steam newly introduced from outside the process system can be reduced. it can.

(Second Embodiment)
The ashless coal production facility 101 shown in FIG. 2 will be described. In addition, regarding the apparatus which comprises this ashless-coal manufacturing equipment 101, the same code | symbol is attached | subjected about the same apparatus as the apparatus which comprises the ashless-coal manufacturing equipment 100 shown in FIG.

  In this embodiment, not the thermal energy held by the vapor solvent generated in the ashless coal acquisition process (for example, the flasher 11), but the thermal energy held by the vapor solvent generated in the extraction process (extraction tank 8). And used as a heat source for heating the slurry in the extraction step (extraction tank 8). Structurally, the vaporized solvent generated in the extraction step (extraction tank 8) is sent to the second heat exchanger 13 via the pipe 22, where the slurry before entering the preheater 7 is heated. ing.

  According to this configuration, the heat energy generated in the extraction process (extraction tank 8) is used as the energy for heating the slurry in the extraction process (extraction tank 8), thereby reducing the amount of slurry heated in the preheater 7. can do. As a result, the heat energy newly introduced from outside the process system (heating energy) can be reduced.

  In the present embodiment, the remaining heat energy is recovered by the exhaust heat recovery boiler 18 as the heat energy of water vapor.

  Moreover, in this embodiment, the heat energy which the solvent of the vapor | steam state generate | occur | produced in the ashless coal acquisition process (for example, flasher 11) holds is heat-recovered with the exhaust heat recovery boiler 19 as heat energy which water vapor | steam has. Structurally, the solvent in the vapor state generated in the ashless coal acquisition step (for example, the flasher 11) is sent to the exhaust heat recovery boiler 19 via the pipe 21 to generate water vapor.

  According to this configuration, the steam (recovered thermal energy) generated in the exhaust heat recovery boiler 19 can be used as low-pressure steam in each step of producing ashless coal, so that it is newly from outside the process system. The amount of low-pressure steam introduced can be reduced.

(Third embodiment)
The ashless coal production facility 102 shown in FIG. 3 will be described. In addition, regarding the apparatus which comprises this ashless coal manufacturing equipment 102, the same code | symbol is attached | subjected about the same apparatus as the apparatus which comprises the ashless coal manufacturing equipment 100 shown in FIG.

  In this embodiment, the heat energy possessed by the vapor solvent generated in the extraction step (extraction tank 8) is used for heating hot oil (heat medium oil) in the third heat exchanger 20. Structurally, the solvent in the vapor state generated in the extraction step (extraction tank 8) is sent to the third heat exchanger 20 via the pipe 22, where the hot oil (heat medium oil) is heated. Yes.

  In the process of producing ashless coal, it is necessary to make the slurry of coal and solvent into a high temperature state of, for example, 250 ° C. or higher. Hot oil (heat medium oil) is one of heating media for heating a slurry of coal and a solvent. For example, when the thin film distillation method is used in the ashless coal acquisition step, hot oil (heat medium oil) is used to heat the thin film distillation tank. Hot oil (heat medium oil) is heated to, for example, 280 to 350 ° C. in the third heat exchanger 20. Conventionally, hot oil (heat medium oil) has been heated by an electric heater.

  According to the above configuration, the heat energy held by the solvent in the vapor state generated in the extraction step (extraction tank 8) is used as a heating source in at least one step (eg, ashless coal acquisition step) for producing ashless coal. By using it for heating hot oil (heat medium oil) used as an electric heater, it is not necessary to introduce an electric heater. Even if the introduction of the electric heater does not become zero, the introduction amount is surely reduced as compared with the conventional case. Therefore, the equipment introduction cost and running cost concerning the electric heater can be reduced.

  Moreover, in this embodiment, among the thermal energy which the solvent of the vapor | steam state generate | occur | produced in the extraction process (extraction tank 8) has, the remaining thermal energy after using it for heating of hot oil (heat medium oil) is 1st. In the heat exchanger 17, it is used as a heat source for solvent heating in the separation step (second gravity settling tank 10). According to this configuration, the second gravity settling tank 10 can be effectively kept warm (heated), and as a result, heat energy (heating energy) newly introduced from outside the process system can be reduced.

  In the present embodiment, the remaining thermal energy is further recovered by the exhaust heat recovery boiler 18 as the thermal energy of water vapor. According to this configuration, waste heat that is wasted can be reduced as much as possible.

<Specific reduction in heat energy newly introduced from outside the process system>
Here, in the ashless coal production facility 102 illustrated in FIG. 3, in the third heat exchanger 20, hot oil (heat medium oil) is heated from 300 ° C. to 320 ° C. (1.25 × 10 ³ kcal / ton − In the first heat exchanger 17, the solvent is heated from 240 ° C. to 280 ° C. (2.37 × 10 ³ kcal / ton-coal processing amount). That is, the heat amount of 1.25 × 10 ³ kcal / ton-coal processing amount in the third heat exchanger 20 and 2.37 × 10 ³ kcal / ton-coal processing amount in the first heat exchanger 17 are expressed as ashless. It can be covered with thermal energy generated from the process (equipment) of charcoal production. Moreover, the heat amount of 0.96 × 10 ³ kcal / ton-coal processing amount can be recovered by the exhaust heat recovery boiler 18 to produce steam.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

1: Coal hopper 2: Solvent tank 3: Slurry preparation tanks 4, 6, 16: Transfer pump 5: Dehydration tank 7: Preheater 8: Extraction tank 9: First gravity settling tank 10: Second gravity settling tanks 11, 12 : Flasher (solvent separator)
13, 17: Heat exchanger 14: Heater for slurry dehydration 18, 19: Waste heat recovery boiler 100: Ashless coal production facility

Claims (9)

A slurry preparation step of preparing a slurry by mixing coal and a solvent;
Extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step;
A separation step of separating the slurry obtained in the extraction step into a solution containing a coal component soluble in the solvent and a solid content concentrate in which a coal component insoluble in the solvent is concentrated;
Ashless coal acquisition step of obtaining ashless coal by evaporating and separating the solvent from the solution separated in the separation step;
In a method for producing ashless coal,
The method for producing ashless coal, characterized in that the thermal energy possessed by the solvent in the vapor state generated in the extraction step is used as a heat source for solvent heating in the separation step . In the manufacturing method of ashless coal of Claim 1 ,
After using the thermal energy possessed by the solvent in the vapor state generated in the extraction step as a heat source for solvent heating in the separation step, the remaining thermal energy is heated in the exhaust heat recovery boiler as the thermal energy possessed by water vapor. A method for producing ashless coal, comprising collecting the ashless coal. A slurry preparation step of preparing a slurry by mixing coal and a solvent;
Extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step;
A separation step of separating the slurry obtained in the extraction step into a solution containing a coal component soluble in the solvent and a solid content concentrate in which a coal component insoluble in the solvent is concentrated;
Ashless coal acquisition step of obtaining ashless coal by evaporating and separating the solvent from the solution separated in the separation step;
In a method for producing ashless coal,
The method for producing ashless coal, characterized in that the thermal energy possessed by the solvent in the vapor state generated in the extraction step is used as a heat source for heating the slurry in the extraction step . A slurry preparation step of preparing a slurry by mixing coal and a solvent;
Extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step;
A separation step of separating the slurry obtained in the extraction step into a solution containing a coal component soluble in the solvent and a solid content concentrate in which a coal component insoluble in the solvent is concentrated;
Ashless coal acquisition step of obtaining ashless coal by evaporating and separating the solvent from the solution separated in the separation step;
In a method for producing ashless coal,
A method for producing ashless coal, characterized in that heat energy held by the solvent in the vapor state generated in the extraction step is recovered by a waste heat recovery boiler as heat energy possessed by water vapor . A slurry preparation step of preparing a slurry by mixing coal and a solvent;
Extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step;
A separation step of separating the slurry obtained in the extraction step into a solution containing a coal component soluble in the solvent and a solid content concentrate in which a coal component insoluble in the solvent is concentrated;
Ashless coal acquisition step of obtaining ashless coal by evaporating and separating the solvent from the solution separated in the separation step;
In a method for producing ashless coal,
A method for producing ashless coal, characterized in that heat energy held by the solvent in the vapor state generated in the ashless coal acquisition step is heat-recovered by a waste heat recovery boiler as heat energy possessed by water vapor . A slurry preparation step of preparing a slurry by mixing coal and a solvent;
Extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step;
A separation step of separating the slurry obtained in the extraction step into a solution containing a coal component soluble in the solvent and a solid content concentrate in which a coal component insoluble in the solvent is concentrated;
Ashless coal acquisition step of obtaining ashless coal by evaporating and separating the solvent from the solution separated in the separation step;
In a method for producing ashless coal,
Further comprising a by-product coal obtaining step of obtaining by-product coal by evaporating and separating the solvent from the solid concentrate separated in the separation step,
A method for producing ashless coal, wherein the heat energy of the solvent in the vapor state generated in the by-product coal acquisition step is recovered by a waste heat recovery boiler as heat energy of water vapor . A slurry preparation step of preparing a slurry by mixing coal and a solvent;
Extracting the coal component soluble in the solvent by heating the slurry obtained in the slurry preparation step;
A separation step of separating the slurry obtained in the extraction step into a solution containing a coal component soluble in the solvent and a solid content concentrate in which a coal component insoluble in the solvent is concentrated;
Ashless coal acquisition step of obtaining ashless coal by evaporating and separating the solvent from the solution separated in the separation step;
In a method for producing ashless coal,
The ashless coal, which is used for heating heat medium oil used as a heating source in at least one step of producing ashless coal, uses the thermal energy held by the solvent in the vapor state generated in the extraction step Manufacturing method. In the manufacturing method of ashless coal according to claim 7 ,
The thermal energy possessed by the solvent in the vapor state generated in the extraction step is used for heating the heating medium oil, and the remaining thermal energy is used as a heat source for heating the solvent in the separation step. A method for producing ashless coal. In the manufacturing method of ashless coal of Claim 8 ,
After using the thermal energy possessed by the solvent in the vapor state generated in the extraction step for heating the heating medium oil, the remaining thermal energy is used as a heat source for heating the solvent in the separation step, and then steam. A method for producing ashless charcoal, characterized in that heat is recovered with a waste heat recovery boiler as the heat energy of the ashless coal.

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