Heating device, unit operation system, and carbon dioxide gas recovery system

Abstract

The present invention aims to provide a heating device that is flexible enough to accommodate self-thermal regeneration even when the compression ratio of the compressor used is low. The present invention also aims to provide a unit operation system and a carbon dioxide gas recovery system that include the heating device. [Solution] A heating device 300 according to one embodiment of the present invention is a device that heats water, which is the fluid to be heated, using a reboiler 330 that uses ethanol vapor introduced from a distillation column 100 as a heating fluid. The heating device 300 is equipped with a preheater 310 that introduces ethanol vapor from the distillation column 100 via a first flow path F1, a compressor 320 connected downstream of the preheater 310 via a second flow path F2, a third flow path F3 that supplies at least a portion of the ethanol vapor compressed by the compressor 320 to the preheater 310 as a preheating source, and a reboiler 330 that introduces the ethanol fluid derived from the third flow path F3 via the preheater 310 as a heating fluid.

Description

[Technical Field]

[0001] The present invention relates to a heating device, a unit operation system, and a carbon dioxide gas recovery system. [Background technology]

[0002] BACKGROUND ART Conventionally, techniques for increasing the temperature of a fluid by compressing it have been known. For example, Patent Document 1 below discloses a heating module shown in Figure 15. This heating module has a piping path in which an input fluid flowing in from input end I is supplied to unit operation unit b via heat exchanger a, and the output fluid output from unit operation unit b is passed through heat exchanger a again before being sent to output end E. Here, on the way from unit operation unit b to output end E, the output fluid is first compressed and heated by compressor c, and then supplied to heat exchanger a. Next, after passing through heat exchanger a, the output fluid is expanded and cooled by expander d, and then cooled by cooling device e. It is explained that this heating module not only has a high energy-saving effect, but also allows the pressure of the fluid input to unit operation unit b to be approximately the same as the pressure of the fluid input to input end I, so that unit operations in unit operation unit b can be performed under approximately constant pressure.

[0003] Furthermore, Patent Document 2 below discloses a distillation apparatus shown in FIG. 16. This distillation apparatus includes a high-pressure column f, a low-pressure column g, a heat exchange structure h, a compressor i, a first line (lines L1A, L2A, and L3A), and a second line (lines L1A and L4A). Here, outlet vapor flowing through the first line passes through the heat exchange structure h, while outlet vapor flowing through the second line does not pass through the heat exchange structure h. Thus, vapor discharged from the top of the low-pressure column g is compressed and heated by the compressor i and supplied to the bottom of the high-pressure column f via the first and second lines. In this distillation apparatus, the heat exchange amount in the heat exchange structure h can be adjusted by adjusting the ratio between the flow rate of the outlet vapor flowing through the first line and the flow rate of the outlet vapor flowing through the second line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5688784 [Patent Document 2] Patent No. 5816476 Summary of the Invention [Problem to be solved by the invention]

[0005] Both Patent Documents 1 and 2 employ a heating device that compresses and heats the process gas. There are two types of compressors used to compress the process gas: oil-lubricated compressors and non-oil-lubricated (oil-free) compressors. When oil-lubricated compressors are used for applications such as self-thermal regeneration distillation, concentration, and stripping, there is a risk of oil mist being mixed into the process gas. Therefore, the use of oil-free compressors is considered essential, particularly for self-thermal regeneration devices and systems that include such devices (e.g., carbon dioxide gas recovery systems). However, due to their internal structure, oil-free compressors have inferior sealing characteristics compared to oil-lubricated compressors, making it difficult to increase the compression ratio. This compression ratio limitation makes it difficult to heat the process gas to the required temperature, resulting in a problem of inflexible application to self-thermal regeneration.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a heating device that is flexible enough to accommodate self-thermal regeneration even when the compression ratio of the compressor used is low. The present invention also aims to provide a unit operation system and a carbon dioxide gas recovery system that include the heating device. [Means for solving the problem]

[0007] In order to solve the above problems and achieve the above object, the present invention employs the following configuration. (1) A heating device according to one aspect of the present invention comprises: An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid source is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; Equipped with.

[0008] According to the heating device described in (1) above, a fluid introduced from a fluid supply source into the preheater through the first flow path is preheated and raised in temperature, and then introduced into the compressor through the second flow path. The fluid introduced into the compressor is then compressed by the compressor and further raised in temperature, and then introduced into the preheater through the third flow path. The preheater uses the heat of the fluid introduced through the third flow path as a preheating source to preheat the fluid traveling from the first flow path through the second flow path toward the compressor. Therefore, the temperature of the fluid can be raised before it is introduced into the compressor. As a result, the compressor can reduce the amount of work it needs to do to compress the fluid until it reaches the temperature required for use as a heating fluid in the heater. This reduces the compression ratio required of the compressor, easing the compression ratio requirements and allowing the use of a non-oil-lubricated compressor.

[0009] (2) In the heating device described in (1) above, The gas turbine engine may further include a fourth flow path that connects the first flow path and the second flow path in a manner that bypasses the preheater. In the heating device described in (2) above, at least a portion of the fluid traveling from the first flow path to the compressor through the second flow path can be diverted to the fourth flow path as needed, allowing the fluid to flow to the compressor without preheating in the preheater. Therefore, the temperature of the fluid supplied to the compressor can be controlled by adjusting the flow rate of the fluid bypassing the preheater by flowing through the fourth flow path as needed. In other words, without bypassing the preheater, the heat of the fluid heated by the compressor travels downstream of the compressor, through the third flow path to the preheater, and then is supplied to the fluid preheated in the preheater and returns to the compressor. In contrast, by diverting at least a portion of the fluid traveling to the preheater through the fourth flow path to bypass the preheater, the amount of preheating applied to the fluid flowing into the compressor can be reduced or eliminated. This reduces heat accumulation in the circulation path. The fourth flow passage may be made of a steel pipe made of carbon steel or stainless steel.

[0010] (3) In the case of the heating device described in (2) above, a first acquisition unit that acquires temperature information corresponding to a temperature and pressure information corresponding to a pressure of the fluid flowing through the third flow path or the fluid compressed by the compressor; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information and the pressure information; may further comprise: In the heating device described in (3) above, when the first flow rate control unit determines that the temperature and pressure of the fluid flowing out of the compressor exceed the appropriate ranges based on the temperature information and pressure information acquired by the first acquisition unit, the flow rate of the fluid flowing through the fourth flow path is increased to increase the flow rate of the fluid bypassing the preheater. This makes it possible to reduce the amount of preheating of the fluid entering the compressor or to perform no preheating at all, thereby suppressing heat accumulation in the circulation path.

[0011] (4) In the case of the heating device described in (2) above, the second flow path includes a confluence flow path that merges the fluid discharged from the downstream side of the preheater and the fluid flowing through the fourth flow path and introduces the merged fluid into the upstream side of the compressor, a second acquisition unit that acquires temperature information corresponding to the temperature of the fluid flowing through the merging channel; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information; may further comprise: In the heating device described in (4) above, the second acquisition unit acquires temperature information of a mixed fluid of a fluid preheated in the preheater and a fluid that bypasses the preheater and is not preheated. If the second flow rate control unit determines that the temperature of the mixed fluid exceeds an appropriate range based on the acquired temperature information, it increases the flow rate of the fluid flowing through the fourth flow path, thereby increasing the flow rate of the fluid bypassing the preheater. This makes it possible to reduce the amount of preheating applied to the fluid heading to the compressor or to adjust to no preheating at all, thereby suppressing heat accumulation in the circulation path.

[0012] (5) In the case of the heating device described in (2) above, a third acquisition unit that acquires temperature information corresponding to the temperature of the fluid flowing through the fourth flow path; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information; may further comprise: In the heating device described in (5) above, when the first flow control unit determines, based on the temperature information acquired by the third acquisition unit, that the temperature of the fluid supplied from the fluid supply source is lower than the appropriate temperature range for the fluid to be sent to the compressor, the flow rate of the fluid flowing through the fourth flow path is reduced. This increases the flow rate of the fluid to be preheated by flowing through the preheater, thereby raising the temperature of the fluid flowing into the compressor and adjusting it to within the appropriate range.

[0013] (6) In the case of the heating device described in (2) above, the second flow path includes a confluence flow path that merges the fluid discharged from the downstream side of the preheater and the fluid flowing through the fourth flow path and introduces the merged fluid into the upstream side of the compressor, a fourth acquisition unit that acquires temperature information corresponding to a temperature of the fluid downstream of the preheater and before the fluid reaches the junction; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information; may further comprise: In the heating device described in (6) above, the fourth acquisition unit acquires temperature information of the fluid preheated by the preheater. If the first flow control unit determines based on the acquired temperature information that the temperature of the preheated fluid exceeds an appropriate range, it increases the flow rate of the fluid bypassing the preheater through the fourth flow path. This reduces the amount of preheating applied to the fluid entering the compressor or eliminates preheating altogether, thereby suppressing heat accumulation in the circulation path.

[0014] (7) In the heating device described in (2) above, The device may further include a fifth flow path connecting the downstream side of the compressor and the heater. In the heating device described in (7) above, by flowing at least a portion of the fluid flowing out of the compressor through the fifth flow path as needed, at least a portion of the fluid can be bypassed without passing through the preheater, thereby suppressing heat accumulation. In other words, without the bypass, the heat of the fluid heated by the compressor travels downstream of the compressor, through the third flow path to the preheater, and then is supplied to the fluid being preheated in the preheater and returns to the compressor, following a circulation path. By flowing at least a portion of the fluid through the fifth flow path and bypassing the preheater, the amount of preheating applied to the fluid flowing into the compressor can be reduced or eliminated. This suppresses heat accumulation in the circulation path. The fifth flow path may be made of a steel pipe made of carbon steel or stainless steel.

[0015] (8) In the heating device described in (7) above, a fifth acquisition unit that acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the fluid flowing within a range downstream of the compressor and upstream of the third flow path; a second flow rate control unit that controls a flow rate of the fluid flowing from the downstream side of the compressor to the third flow path and a flow rate of the fluid flowing from the downstream side of the compressor to the fifth flow path in accordance with the temperature information and the pressure information; may further comprise: In the heating device described in (8) above, when the second flow control unit determines that the temperature and pressure of the fluid flowing out of the compressor exceed the appropriate range based on the temperature information and pressure information acquired by the fifth acquisition unit, the second flow control unit reduces the flow rate of the fluid flowing through the third flow path and causes the remaining fluid to flow through the fifth flow path, thereby bypassing the preheater. This makes it possible to adjust the amount of preheating applied to the fluid entering the compressor to be low or to perform no preheating at all, thereby suppressing heat accumulation in the circulation path.

[0016] (9) In the heating device described in (1) above, The device may further include a fifth flow path connecting the downstream side of the compressor and the heater. In the heating device described in (9) above, by flowing at least a portion of the fluid flowing out of the compressor through the fifth flow path as needed, at least a portion of the fluid can be bypassed without passing through the preheater, thereby suppressing heat accumulation. In other words, without bypassing, the heat of the fluid heated by the compressor travels downstream of the compressor, through the third flow path to the preheater, and then is supplied to the fluid being preheated in the preheater and returns to the compressor, following a circulation path. By flowing at least a portion of the fluid through the fifth flow path and bypassing the preheater, the amount of preheating applied to the fluid flowing into the compressor can be reduced or eliminated. This suppresses heat accumulation in the circulation path. The fifth flow path may be made of a steel pipe made of carbon steel or stainless steel.

[0017] (10) In the heating device described in (9) above, a first acquisition unit that acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the fluid flowing within a range downstream of the compressor and upstream of the third flow path; a second flow rate control unit that controls a flow rate of the fluid flowing from the downstream side of the compressor to the third flow path and a flow rate of the fluid flowing from the downstream side of the compressor to the fifth flow path in accordance with the temperature information and the pressure information; may further comprise: In the heating device described in (10) above, when the second flow rate control unit determines, based on the temperature information and pressure information acquired by the first acquisition unit, that the temperature and pressure of the fluid flowing out of the compressor exceed the appropriate range, the flow rate of the fluid flowing through the third flow path is reduced and the remaining fluid is caused to flow through the fifth flow path, thereby bypassing the preheater. This makes it possible to adjust the amount of preheating applied to the fluid heading towards the compressor to be low or to perform no preheating at all, thereby suppressing heat accumulation in the circulation path.

[0018] (11) In the heating device described in (9) above, a second acquisition unit that acquires temperature information corresponding to a temperature of the fluid before compression that flows into the compressor; a second flow rate control unit that controls a flow rate of the fluid flowing from the downstream side of the compressor to the third flow path and a flow rate of the fluid flowing from the downstream side of the compressor to the fifth flow path in accordance with the temperature information; may further comprise: In the heating device described in (11) above, the second acquisition unit acquires temperature information of a mixed fluid of a fluid preheated in the preheater and a fluid that bypasses the preheater and is not preheated. If the second flow rate control unit determines that the temperature of the mixed fluid exceeds an appropriate range based on the acquired temperature information, the flow rate of the fluid flowing through the third flow path is reduced and the remaining fluid is flowed through the fifth flow path, bypassing the preheater. This makes it possible to reduce the amount of preheating applied to the fluid heading to the compressor or to adjust to no preheating at all, thereby suppressing heat accumulation in the circulation path.

[0019] (12) In the heating device according to any one of (1) to (11) above, The compressor may be driven by electricity derived from renewable energy. In the case of the heating device described in (12) above, by using electricity derived from renewable energy as the power source for the compressor, it is possible to further enhance the effect of reducing environmental load in addition to the effect of self-heat regeneration.

[0020] (13) A unit operation system according to one aspect of the present invention, The heating device according to any one of (1) to (11) above, A unit operation apparatus that performs at least one of distillation, stripping, concentration, drying, and evaporation on a unit operation fluid using the heated fluid heated by the heater; Equipped with. According to the unit operation system described in (13) above, a heating device equipped with an oil-free compressor can be employed, so that the problem of oil mist being mixed into the process gas can be avoided even when this unit operation system is used for applications such as self-heat regenerating distillation, concentration, and stripping. Distillation is a method of separating components of a mixture by utilizing the difference in boiling points, and is mainly used for separating and purifying liquid mixtures. Concentration is a process of increasing the concentration of a solute by reducing the amount of solvent in a solution. Stripping is a process of removing remaining gas from a liquid using steam or the like.

[0021] (14) In the unit operation system described in (13) above, The compressor may be driven by electricity derived from renewable energy. In the case of the unit operation system described in (14) above, by using electricity derived from renewable energy as the power source for the compressor, it is possible to further enhance the effect of reducing environmental impact in addition to the effect of self-thermal regeneration.

[0022] (15) A carbon dioxide gas recovery system according to one aspect of the present invention includes: an absorption tower that introduces a gas to be separated containing carbon dioxide gas and a lean absorption liquid into the gas to be separated, and causes the carbon dioxide gas in the gas to be separated to be absorbed by the lean absorption liquid to produce a rich absorption liquid; a regeneration tower to which the rich absorbing liquid is supplied from the absorption tower and which heats the rich absorbing liquid to separate the carbon dioxide gas and thereby regenerate the rich absorbing liquid into the lean absorbing liquid; a heating device that heats the rich absorption liquid while it is being withdrawn from the regeneration tower and reintroduced into the regeneration tower; Equipped with The heating device is the heating device according to any one of (1) to (11) above, the fluid supply source is the regeneration tower, the fluid introduced from the fluid supply source is a mixed gas of the carbon dioxide gas and the solute and solvent vapor components of the rich absorption liquid, which is discharged from the regeneration tower; The fluid to be heated is the rich absorbing liquid. According to the carbon dioxide gas recovery system described in (15) above, a heating device equipped with a non-oil-lubricated compressor can be employed, so that the problem of oil mist being mixed into the process gas can be avoided.

[0023] (16) In the carbon dioxide gas recovery system described in (15), The compressor may be driven by electricity derived from renewable energy. In the case of the carbon dioxide gas recovery system described in (16) above, by using electricity derived from renewable energy as the power source for the compressor, it is possible to further enhance the effect of reducing environmental impact in addition to the effect of self-thermal regeneration. [Effects of the Invention]

[0024] According to the above-mentioned aspects of the present invention, it is possible to provide a heating device that is flexible enough to accommodate self-thermal regeneration even when the compression ratio of the compressor used is low. Furthermore, according to the above-mentioned aspects of the present invention, it is possible to provide a unit operation system and a carbon dioxide gas recovery system that include the heating device. [Brief explanation of the drawings]

[0025] [Figure 1]FIG. 1 is a schematic diagram showing a distillation system, which is an example of a unit operation system equipped with a heating device according to one embodiment of the present invention. [Figure 2] FIG. 4 is a schematic configuration diagram showing a first modified example of the embodiment. [Figure 3] FIG. 10 is a schematic configuration diagram showing a second modified example of the embodiment. [Figure 4] FIG. 10 is a schematic configuration diagram showing a third modified example of the embodiment. [Figure 5] FIG. 10 is a schematic configuration diagram showing a fourth modified example of the embodiment. [Figure 6] FIG. 10 is a schematic configuration diagram showing a fifth modified example of the embodiment. [Figure 7] FIG. 10 is a schematic configuration diagram showing a sixth modified example of the embodiment. [Figure 8] This is a schematic diagram showing a carbon dioxide gas recovery system, which is another example of a unit operation system equipped with a heating device according to one embodiment of the present invention. [Figure 9] 9 is a diagram showing a first modified example of the embodiment, and is a schematic configuration diagram showing part B of FIG. 8. FIG. [Figure 10] 9 is a diagram showing a second modified example of the embodiment, and is a schematic configuration diagram showing part B of FIG. 8. FIG. [Figure 11] 9 is a diagram showing a third modified example of the embodiment, and is a schematic configuration diagram showing part B of FIG. 8. FIG. [Figure 12] 9 is a diagram showing a fourth modified example of the embodiment, and is a schematic configuration diagram showing part B of FIG. 8. FIG. [Figure 13] 9 is a diagram showing a fifth modified example of the embodiment, and is a schematic configuration diagram showing part B of FIG. 8. FIG. [Figure 14] 8. FIG. 10 is a diagram showing a sixth modified example of the embodiment, and is a schematic configuration diagram showing part B of FIG. [Figure 15] FIG. 1 is a schematic diagram of a conventional heating module described in Patent Document 1. [Figure 16] FIG. 1 is a schematic diagram of a conventional internal heat exchange type distillation column described in Patent Document 2. DETAILED DESCRIPTION OF THE INVENTION

[0026] Each embodiment and their modified examples relating to the heating device, unit operation system, and carbon dioxide gas recovery system of the present invention will be described below. First, a distillation system shown in FIG. 1 will be described as a first embodiment of a unit operation system equipped with the heating device of the present invention. Then, modified examples of the distillation system will be described with reference to FIGS. 2 to 7. Next, a carbon dioxide gas recovery system shown in FIG. 8 will be described as a second embodiment of a unit operation system equipped with the heating device of the present invention. Then, modified examples of the carbon dioxide gas recovery system will be described with reference to FIGS. 9 to 14.

[0027] [First embodiment: distillation system] In general, a distillation system is a system that separates components of a mixture by utilizing the difference in boiling points, and is mainly used for separating and purifying liquid mixtures. In this embodiment, a distillation system for an ethanol / water system will be described as an example. That is, in the distillation system of this embodiment, a distillation raw material liquid consisting of water and ethanol is taken into the distillation column 100 as a raw material, and this distillation raw material liquid is distilled to separate and recover liquid ethanol and water. Here, the distillation raw material liquid taken into the distillation column 100 can be exemplified by a mixed fluid of 10% ethanol and 90% water. As shown in FIG. 1, a distillation system 1000 of this embodiment includes a distillation column 100 and a heating device 300.

[0028] Distillation column 100 is a vertically long hollow vessel, and its top is provided with a steam outlet through which ethanol vapor separated by distillation is taken out. The bottom of distillation column 100 is provided with a pooled water outlet through which water accumulated therein is taken out. A reflux inlet is provided on the side of the upper part of distillation column 100 for taking in reflux liquid ethanol introduced from reboiler 330 (described below). A heating fluid inlet is provided on the side of the lower part of distillation column 100 for taking in the heating fluid (a mixture of hot water and steam) introduced from reboiler 330 into the column. Therefore, distillation column 100 is connected to heating device 300 at four locations: the vapor outlet, the pooled water outlet, the reflux inlet, and the heating fluid inlet.

[0029] The heating device 300 includes a preheater 310, a compressor 320, a reboiler (heater) 330, a cooler 340, a branching section 350, pipes connecting these, control valves and pumps (neither of which are shown) provided in these pipes, and a control device (not shown). Preheater 310 is a heat exchanger that uses a preheat source to heat ethanol vapor extracted from the top of distillation column 100. A vapor outlet of distillation column 100 and preheater 310 are connected by a pipe that forms a first flow path F1. That is, the upstream end of first flow path F1 is connected to the vapor outlet of distillation column 100, and the downstream end of first flow path F1 is connected to preheater 310.

[0030] The compressor 320 is a device that compresses the ethanol vapor preheated by the preheater 310 to further increase the temperature. Compressors are generally of oil-lubricated and non-oil-lubricated types, but for reasons described below, a non-oil-lubricated compressor is used as the compressor 320 of this heating device 300. It is preferable to use electricity derived from renewable energy to drive the compressor 320. In this case, carbon dioxide emissions from the heating device 300 can be reduced.

[0031] The preheater 310 and the suction port of the compressor 320 are connected by a pipe forming a second flow path F2. That is, the upstream end of the second flow path F2 is connected to the preheater 310, and the downstream end of the second flow path F2 is connected to the suction port of the compressor 320. The ethanol vapor compressed and heated by the compressor 320 is supplied to the preheating source inlet of the preheater 310 via a pipe forming the third flow path F3. That is, the upstream end of the third flow path F3 is connected to the discharge port of the compressor 320, and the downstream end of the third flow path F3 is connected to the preheating source inlet of the preheater 310.

[0032] The first flow path F1 and the second flow path F2 are connected by a pipe forming a fourth flow path F4, which directs some or all of the ethanol vapor flowing through the first flow path F1 to the second flow path F2, bypassing the preheater 310. Specifically, the upstream end of the fourth flow path F4 is connected to a connection point p1 located midway between one end and the other end of the first flow path F1, and the downstream end of the fourth flow path F4 is connected to a connection point p2 located midway between one end and the other end of the second flow path F2. A T-shaped pipe is provided at this connection point p1, connecting the pipe forming the first flow path F1 to the pipe forming the fourth flow path F4. This T-shaped pipe allows the ethanol vapor flowing through the first flow path F1 to branch into a flow toward the preheater 310 and a flow toward the fourth flow path F4. A flow control valve (not shown) is connected midway between the connection point p1 and the preheater 310 on the pipe forming the first flow path F1. In addition, a flow control valve (not shown) is connected to the piping that forms the fourth flow path F4. Hereinafter, the flow control valve provided in the first flow path F1 and the flow control valve provided in the fourth flow path F4 may be collectively referred to as a first bypass amount control valve.

[0033] The flow control valves provided in the first flow path F1 and the fourth flow path F4 are each electrically connected to the control device. Note that "electrically connected" here is not limited to direct connection by wiring or the like, but also includes connection via a line such as wireless or the Internet. The flow control valve provided in the first flow path F1 adjusts the flow rate of ethanol vapor flowing from the first flow path F1 to the preheater 310 in response to instructions from the control device. The flow control valve provided in the fourth flow path F4 adjusts the flow rate of ethanol vapor flowing from the first flow path F1 to the second flow path F2 through the fourth flow path F4, which bypasses the preheater 310. By using the first bypass amount control valve, when the total flow rate of ethanol vapor flowing through the first flow path F1 is set to 100%, the proportion of ethanol vapor passing through the preheater 310 can be adjusted between 0% and 100%, and the proportion of ethanol vapor flowing through the fourth flow path F4 can be adjusted to the remainder (i.e., 100% to 0%) obtained by subtracting the flow rate of ethanol vapor flowing through the first flow path F1 from the total flow rate.

[0034] In order to allow a high-temperature, high-pressure fluid to flow smoothly, it is preferable to use a steel pipe made of carbon steel or stainless steel as the fourth flow path F4. Since ethanol vapor (gas) flows through the fourth flow path F4, it is more preferable to use a pipe made of carbon steel.

[0035] The reboiler 330 is a heat exchanger that takes in and heats the water stored at the bottom of the distillation column 100. The reboiler 330 uses, as its heat source, an ethanol fluid (a mixed fluid of ethanol vapor and liquid ethanol) taken in through a preheating fluid outlet of the preheater 310. The preheater 310 and the reboiler 330 are connected by a pipe that forms a sixth flow path F6. That is, the upstream end of the sixth flow path F6 is connected to the preheating fluid outlet of the preheater 310, and the downstream end of the sixth flow path F6 is connected to the heating fluid inlet of the reboiler 330.

[0036] A connection point p3 located midway along the sixth flow path F6 and a connection point p4 located midway along the third flow path F3 are connected by a pipe forming a fifth flow path F5. A part or all of the ethanol vapor flowing out of the compressor 320 can be sent via the fifth flow path F5 to the sixth flow path F6 and further to the reboiler 330. That is, a T-shaped pipe is provided at the connection point p4, connecting the pipe from the discharge port of the compressor 320 to the connection point p4, the pipe forming the third flow path F3, and the pipe forming the fifth flow path F5. This T-shaped pipe allows the ethanol vapor discharged from the compressor 320 to branch into a flow toward the third flow path F3 and a flow toward the sixth flow path F6 via the fifth flow path F5. Herein, a flow control valve (not shown) is connected to the pipe forming the third flow path F3. Similarly, a flow control valve (not shown) is also connected to the pipe forming the fifth flow path F5. Hereinafter, the flow control valve provided in the third flow path F3 and the flow control valve provided in the fifth flow path F5 may be collectively referred to as the second bypass amount control valve. The flow control valves provided in the third flow path F3 and the fifth flow path F5 are each electrically connected to the control device. Note that "electrically connected" here does not necessarily mean a direct connection via wiring or the like, but also includes connection via a communication line such as wireless or the Internet. The flow control valve provided in the third flow path F3 receives instructions from the control device to adjust the flow rate of ethanol vapor that flows from the discharge port of the compressor 320 through the third flow path F3 to the preheating source inlet of the preheater 310. The flow control valve provided in the fifth flow path F5 adjusts the flow rate of ethanol vapor that flows from the discharge port of the compressor 320 through the fifth flow path F5 and bypasses it to the sixth flow path F6.

[0037] The second bypass amount control valve can adjust the proportion of ethanol vapor flowing to the preheater 310 between 0% and 100% when the total flow rate of ethanol vapor discharged from the discharge port of the compressor 320 is 100%, and can also adjust the proportion of ethanol vapor that bypasses the preheater 310 by passing from the discharge port of the compressor 320 through the fifth flow path F5 to the remainder (i.e., 100% to 0%) obtained by subtracting the flow rate of ethanol vapor flowing to the preheater 310 from the total flow rate. In other words, the second bypass amount control valve can adjust the proportion of ethanol vapor that bypasses the preheater 310 by passing through the fifth flow path F5 between 0% and 100%, and can also adjust the proportion of ethanol vapor that flows from the discharge port of the compressor 320 to the preheater 310 to the remainder (i.e., 100% to 0%) obtained by subtracting the flow rate of ethanol vapor flowing through the fifth flow path F5 from the total flow rate.

[0038] In addition, from the viewpoint of allowing high-temperature and high-pressure fluid to flow smoothly, it is preferable to use a steel pipe made of carbon steel or stainless steel as the fifth flow path F5. Since the fifth flow path F5 carries ethanol vapor (gas), it is more preferable to use a pipe made of carbon steel.

[0039] The ethanol fluid supplied as a heat source from the sixth flow path F6 to the reboiler 330 heats the water at the bottom of the distillation column 100, and then flows through a pipe forming a seventh flow path F7 to the cooler 340. The reboiler 330 and the cooler 340 are connected by the seventh flow path F7. That is, the upstream end of the seventh flow path F7 is connected to the reboiler 330, and the downstream end of the seventh flow path F7 is connected to the cooler 340.

[0040] The ethanol fluid flowing from the reboiler 330 to the cooler 340 is cooled in the cooler 340 to become liquid ethanol, which then flows toward the branching section 350. The cooler 340 and the branching section 350 are connected by a pipe forming an eighth flow path F8. That is, the upstream end of the eighth flow path F8 is connected to the cooler 340, and the downstream end of the eighth flow path F8 is connected to the liquid ethanol intake port of the branching section 350.

[0041] A portion of the liquid ethanol flowing through the eighth flow path F8 passes through the branching section 350 and heads toward the tenth flow path F10, where it is recovered. The remaining portion is separated at the branching section 350 for reflux and supplied to the distillation column 100 through a reflux inlet located on the upper side of the distillation column 100. The upstream ends of the tenth flow path F10 and the ninth flow path F9 are both connected to the liquid ethanol outlet port of the branching section 350. The flow rate of the reflux (liquid ethanol) supplied to the distillation column 100 from the branching section 350 through the ninth flow path F9 may be constant, or may be automatically adjusted by the control device according to the amount of ethanol vapor produced in the distillation column 100, for example.

[0042] As described above, the reboiler 330 is a heat exchanger that takes in and heats water stored at the bottom of the distillation column 100. The outward path between the reboiler 330 and the bottom of the distillation column 100 is composed of the eleventh flow path F11, a pump (not shown), a branching section 360, and the twelfth flow path F12. That is, the upstream end of the eleventh flow path F11 is connected to a stored water outlet at the bottom of the distillation column 100, and the downstream end of the eleventh flow path F11 is connected to a stored water inlet of the branching section 360. Then, downstream of the branching section 360, the flow branches into two, one of which is connected to the reboiler 330 and the other of which is connected to a water tank (not shown) via the thirteenth flow path F13. The return path between the reboiler 330 and the bottom of the distillation column 100 is connected via a fourteenth flow path F14. That is, the upstream end of the fourteenth flow path F14 is connected to the reboiler 330, and the downstream end of the fourteenth flow path F14 is connected to a lower side of the distillation column 100.

[0043] The operation of the distillation system 1000 explained above will now be described. First, in the reboiler 330, water stored at the bottom of the distillation column 100 is introduced into the reboiler 330 via an outward path consisting of the eleventh flow path F11, the branching section 360, and the twelfth flow path F12. The introduced water flows through heat exchange tubes (not shown) provided in the reboiler 330. Meanwhile, ethanol fluid compressed and heated by the compressor 320 flows around the outside of the heat exchange tubes, transferring its heat to the water in the heat exchange tubes through the wall surfaces of the heat exchange tubes. As a result, the water at the bottom of the column is heated by the ethanol fluid and becomes a heated fluid (a mixture of hot water and steam). After leaving the reboiler 330, this heated fluid is introduced into the distillation column 100 from the lower side via the fourteenth flow path F14, which is the return path.

[0044] Meanwhile, in distillation column 100, the raw material supplied into the column, i.e., the distillation raw material liquid consisting of water and ethanol, is heated by the heating fluid supplied to the column bottom from reboiler 330. The heated distillation raw material liquid is separated into ethanol vapor and water due to the difference in boiling points between ethanol and water. The relatively light ethanol vapor rises within the column, while the relatively heavy water accumulates at the column bottom. Ethanol vapor reaching the top of the distillation column 100 is introduced into the preheater 310 through the first flow path F1. The introduced ethanol vapor flows through heat exchange tubes (not shown) provided in the preheater 310. Meanwhile, ethanol vapor heated by compression in the compressor 320 and supplied from the third flow path F3 flows around the outside of the heat exchange tubes, transferring its heat to the ethanol vapor inside the heat exchange tubes through the wall surfaces of the heat exchange tubes. In this way, the ethanol vapor heated by compression in the compressor 320 is used as a preheating source to preheat the ethanol vapor flowing inside the preheater 310. Therefore, since the ethanol vapor compressed by the compressor 320 is used as a preheating source, no external heating source is required.

[0045] The ethanol vapor preheated in the preheater 310 is supplied to the compressor 320 through the second flow path F2. The ethanol vapor is then compressed by the compressor 320, where it is heated and pressurized, before flowing to the third flow path F3. The ethanol vapor flowing through the third flow path F3 is supplied to the preheater 310 as a preheating source, where it heats and raises the temperature of the ethanol vapor traveling from the first flow path F1 to the second flow path F2. The ethanol fluid preheated in the preheater 310 is then supplied to the reboiler 330 through the sixth flow path F6. As described above, the reboiler 330 uses the heat of the ethanol fluid supplied from the sixth flow path F6 to heat the water at the bottom of the distillation column 100, converting it into a heated fluid, which is then returned to the bottom. Distillation continues within the distillation column 100, utilizing the heat of this heated fluid. Of the water flowing from the bottom of the column into the eleventh flow path F11, the surplus water other than that supplied to the reboiler 330 is separated in the branching section 360 and discharged into the thirteenth flow path F13.

[0046] Meanwhile, the ethanol fluid supplied from sixth flow path F6 to reboiler 330, which has completed its role as a heat source, is introduced into cooler 340 via seventh flow path F7, where it is cooled and becomes liquid ethanol. A portion of the liquid ethanol flowing through eighth flow path F8 is recovered via tenth flow path F10, while the remaining portion is separated at branching section 350 for reflux and supplied to the reflux inlet of distillation column 100.

[0047] Of the first flow path F1 to the fourteenth flow path F14 described above, the fourth flow path F4 and the fifth flow path F5 are pipes made of carbon steel, but for the other pipes, if the fluid flowing therethrough is at high temperature and pressure, pipes made of carbon steel or pipes made of stainless steel may also be used. In this case, it is more preferable to use pipes made of carbon steel when the fluid flowing therethrough is only gas, and to use pipes made of stainless steel when the fluid flowing therethrough is liquid or a gas-liquid mixture.

[0048] As described above, compressors are generally classified into oil-lubricated and non-oil-lubricated types, and the compressor 320 of this embodiment is of the non-oil-lubricated type. The reason for this is that if an oil-lubricated compressor is used as the compressor 320, there is a risk that oil mist may be mixed into the ethanol vapor passing through the compressor 320. Therefore, an oil-free compressor is adopted, but because its sealing characteristics are inferior to those of an oil-lubricated compressor, another problem arises: it is difficult to increase the compression ratio. Therefore, simply adopting an oil-free compressor 320 would not be able to heat the ethanol vapor to the required temperature, and the compressor may be insufficient as a heat source to supply to the heater 330. If the amount of heat is insufficient, the temperature of the heating fluid supplied to the distillation column 100 will naturally not be sufficient, which may cause problems in the operation of the distillation itself.

[0049] Therefore, in the heating device 300 of this embodiment, ethanol vapor heated by compression in the compressor 320 is supplied to the preheater 310 as a preheating source, and self-thermal regeneration is adopted in which the ethanol vapor passing through the preheater 310 is preheated using this preheating source. According to this configuration, by raising the temperature of the ethanol vapor before compression in advance, it is possible to reduce the amount of compression required to raise the temperature to the required level at the discharge port of the compressor 320. As a result, the compression ratio required of the compressor 320 is reduced, and the discharge pressure of the compressor 320 can be reduced. Therefore, it is possible to raise the temperature of the ethanol vapor to the required level while lowering the discharge pressure of the compressor 320.

[0050] In addition to such self-heat regeneration, the heating device 300 of this embodiment is characterized by being provided with the fourth flow path F4 and the fifth flow path F5 described above. To explain this, first, the heating device 300 of this embodiment employs self-heat regeneration as described above, and supplies a portion of the heat contained in the ethanol vapor discharged from the compressor 320 via the preheater 310 to the ethanol vapor before it is taken into the compressor 320. As a result, a circulation path is formed for the heat flow, from the compressor 320 through the third flow path F3, the preheater 310, and the second flow path F2, before returning to the compressor 320. In this circulation path, some heat may be accumulated during the self-heat regeneration process, but the amount of accumulated heat can be reduced by using one or both of the fourth flow path F4 and the fifth flow path F5.

[0051] That is, when the fourth flow path F4 is used, the ethanol vapor flowing through the first flow path F1 is made to bypass the preheater 310 and flow through the second flow path F2, thereby reducing or eliminating the amount of heat received by the preheater 310. This prevents an excessive increase in the amount of heat stored in the circulation path. Similarly, when the fifth flow path F5 is used, the ethanol vapor compressed and heated by the compressor 320 can be passed through the sixth flow path F6, bypassing the preheater 310, so that the flow rate of the preheat source supplied to the preheater 310 can be reduced or cut off. This prevents the amount of heat stored in the circulation path from increasing excessively. In this way, when adjusting using the fourth flow path F4, the amount of heat received is limited, and when adjusting using the fifth flow path F5, the amount of heat generated is limited, making it possible to prevent excessive heat accumulation in the circulation path. Either the control of the amount of heat received or the control of the amount of heat generated may be performed, or both may be performed simultaneously. In other words, while the present embodiment illustrates the case where the fourth flow path F4 and the fifth flow path F5 are provided in parallel, this configuration is not limiting. For example, the fifth flow path F5 may be omitted and only the amount of heat received by the fourth flow path F4 may be adjusted, or the fourth flow path F4 may be omitted and only the amount of heat generated by the fifth flow path F5 may be adjusted. Alternatively, as shown in FIG. 1, the fourth flow path F4 and the fifth flow path F5 may be provided in parallel, and the amount of heat received by the fourth flow path F4 and the amount of heat generated by the fifth flow path F5 may be adjusted simultaneously or at appropriate timings.

[0052] In the fourth flow path F4, the flow rate of the ethanol vapor flowing from the first flow path F1 to the preheater 310 and the flow rate of the ethanol vapor flowing from the first flow path F1 to the fourth flow path F4 and bypassing the preheater 310 may be appropriately adjusted with reference to the state of the fluid flowing at each position in the circulation path (fluid temperature, fluid pressure). Alternatively, flow path switching control may be performed such that all (100%) of the ethanol vapor flowing through the first flow path F1 flows to only one of the fourth flow path F4 and the preheater 310 and not the other. Similarly, for the fifth flow path F5, the flow rate of the ethanol vapor flowing through the third flow path F3 and the flow rate of the ethanol vapor bypassing the preheater 310 by flowing through the sixth flow path F6 via the fifth flow path F5 may be appropriately adjusted with reference to the state (fluid temperature, fluid pressure) of the fluid flowing through each position in the heating device 300. Alternatively, flow path switching control may be performed such that all (100%) of the ethanol vapor compressed by the compressor 320 flows through only one of the fifth flow path F5 and the third flow path F3 and not the other. The specific content of the control that refers to the state (fluid temperature, fluid pressure) of the fluid flowing through the circulation path will be described later as first to sixth modified examples based on FIGS.

[0053] The essential features of the heating device 300 described above are summarized below. That is, the heating device 300 of this embodiment is This is an apparatus for heating water (a fluid to be heated) introduced from the bottom of a distillation column (a fluid supply source) 100 by a reboiler (heater) 330 using ethanol vapor, which is a fluid introduced from the top of the distillation column (a fluid supply source) 100, as a heating fluid, a preheater 310 into which ethanol vapor from the top of the distillation column 100 is introduced via a first flow path F1; a compressor 320 connected downstream of the preheater 310 via a second flow path F2; a third flow path F3 that supplies at least a portion of the ethanol vapor compressed by the compressor 320 to the preheater 310 as a preheating source; a reboiler 330 that introduces, as a heating fluid, the ethanol fluid that has been discharged from the third flow path F3 via the preheater 310; Equipped with.

[0054] According to the heating device 300, ethanol vapor introduced into the preheater 310 from the top of the distillation column 100 via the first flow path F1 is preheated to increase its temperature, and then introduced into the compressor 320 via the second flow path F2. The ethanol vapor introduced into the compressor 320 is then compressed by the compressor 320 to further increase its temperature, and then introduced into the preheater 310 via the third flow path F3. The preheater 310 uses the heat of the ethanol vapor introduced via the third flow path F3 as a preheat source to preheat the ethanol vapor traveling from the first flow path F1 through the second flow path F2 to the compressor 320. Therefore, the temperature of the ethanol vapor can be raised before it is introduced into the compressor 320. As a result, the amount of work required by the compressor 320 to compress the ethanol vapor to a temperature required for use as a heating fluid in the reboiler 330 can be reduced. This relaxes the compression ratio requirement for the compressor 320, allowing a non-oil-lubricated compressor 320 to be used.

[0055] Furthermore, the heating device 300 of this embodiment has the following features: The gas turbine further includes a fourth flow path F4 that connects the first flow path F1 and the second flow path F2, bypassing the preheater 310. According to this configuration, at least a portion of the ethanol vapor traveling from the first flow path F1 through the second flow path F2 to the compressor 320 can be passed through the fourth flow path F4 as needed, allowing the ethanol vapor to flow to the compressor 320 without being preheated by the preheater 310. Therefore, by adjusting the flow rate of the ethanol vapor flowing through the fourth flow path F4 and bypassing the preheater 310 as needed, the temperature of the ethanol vapor supplied to the compressor 320 can be controlled to an appropriate temperature. Specifically, the heat of the ethanol vapor heated by the compressor 320 travels downstream of the compressor 320, passes through the third flow path F3 to the preheater 310, is supplied to the ethanol vapor preheated by the preheater 310, and then returns to the compressor 320. However, by using the fourth flow path F4, which bypasses the preheater 310, the amount of preheating can be kept low or can be adjusted to eliminate preheating altogether. This reduces heat accumulation before and after the compressor 320.

[0056] Furthermore, the heating device 300 of this embodiment has the following features: The system further includes a fifth flow path F5 that connects the downstream side of the compressor 320 and the reboiler 330 via a sixth flow path F6. According to this configuration, by flowing at least a portion of the ethanol vapor flowing out of the compressor 320 through the fifth flow path F5 as needed, at least a portion of the ethanol vapor can be bypassed without passing through the preheater 310, thereby suppressing heat accumulation. In other words, without the bypass, the heat of the ethanol vapor heated by the compressor 320 travels downstream of the compressor 320 through the third flow path F3 to the preheater 310, is supplied to the ethanol vapor preheated by the preheater 310, and then returns to the compressor 320, following a circulation path. In contrast, by flowing at least a portion of the ethanol vapor through the fifth flow path F5 to bypass the preheater 310, the amount of preheating applied to the ethanol vapor flowing into the compressor 320 can be reduced or eliminated altogether. This suppresses heat accumulation in the circulation path.

[0057] Furthermore, the distillation system 1000 of this embodiment has The heating device 300, A distillation column (unit operation apparatus) 100 that distills a raw material (unit operation fluid) using a heated fluid (a gas-liquid mixture fluid of water and steam) heated by a reboiler 330; Equipped with. According to this configuration, the distillation operation can be performed without using a heat source such as steam in the reboiler 330.

[0058] Furthermore, in the distillation system 1000 of this embodiment, The compressor 320 may be powered by electricity derived from renewable energy sources. In this case, by using electricity derived from renewable energy as the power source for the compressor 320, it is possible to further enhance the effect of reducing the environmental load in addition to the effect of self-heat regeneration.

[0059] <First Modification> In the distillation system 1000, the heating device 400 shown in Fig. 2 may be used instead of the heating device 300 shown in Fig. 1. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information and pressure information of the ethanol vapor discharged from the compressor 320. The heating device 400 of this modified example is provided with a first acquisition unit S1 at the discharge port of the compressor 320 or at a pipe connected thereto, which acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the ethanol vapor immediately after being compressed by the compressor 320. An example of this first acquisition unit S1 is a combination of a thermometer such as a thermocouple and a pressure gauge equipped with a piezoelectric element.

[0060] Furthermore, the heating device 400 of this modified example includes a first flow control unit C1 instead of the first bypass amount control valve provided downstream of the connection point p1. This first flow control unit C1 controls the flow rate of ethanol vapor flowing through the fourth flow path F4 in accordance with the temperature and pressure information acquired by the first acquisition unit S1. As shown by the dashed lines in FIG. 2 , the first flow control unit C1 has a communication function that can acquire temperature and pressure information from the first acquisition unit S1 via wired or wireless communication, and a control function that adjusts its own valve opening based on the acquired temperature and pressure information. With this configuration, the temperature and pressure information acquired by the first acquisition unit S1 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts its own valve opening to the required level based on the acquired temperature and pressure information. This controls the flow rate of ethanol vapor flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0061] Alternatively, the control device may be connected between the first acquisition unit S1 and the first flow rate control unit C1 via a wired or wireless communication line so that they can communicate with each other. In this case, the temperature and pressure information acquired by the first acquisition unit S1 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature and pressure information. The first flow rate control unit C1 then adjusts the valve opening accordingly. This controls the flow rate of the ethanol vapor flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4, bypassing the preheater 310. Therefore, according to the configuration of this modified example, it is possible to reliably prevent an excessive increase in the amount of heat stored in the heat circulation path described above, which exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2, and then returns to the compressor 320.

[0062] <Second Modification> In the distillation system 1000, the heating device 300 shown in Fig. 1 may be replaced with the heating device 500 shown in Fig. 3. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information of the ethanol vapor before the intake port of the compressor 320. In the heating device 500 of this modified example, a second acquisition unit S2 that acquires temperature information corresponding to the temperature of the ethanol vapor immediately before being compressed by the compressor 320 is provided in a pipe that forms a junction flow path F2a formed between the junction point p2, which is the junction point of the second flow path F2 with the fourth flow path F4, and the intake port of the compressor 320. An example of this second acquisition unit S2 is a thermometer such as a thermocouple.

[0063] Furthermore, the heating device 500 of this modified example includes a first flow control unit C1 instead of the first bypass amount control valve provided downstream of the connection point p1. This first flow control unit C1 controls the flow rate of ethanol vapor flowing through the fourth flow path F4 in accordance with temperature information acquired by the second acquisition unit S2. As shown by the dashed line in FIG. 3 , the first flow control unit C1 has a communication function that can acquire temperature information from the second acquisition unit S2 via wired or wireless communication and a control function that adjusts its own valve opening based on the acquired temperature information. With this configuration, the temperature information acquired by the second acquisition unit S2 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts itself to the required valve opening based on the acquired temperature information. This controls the flow rate of ethanol vapor flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0064] Alternatively, the control device may be connected between the second acquisition unit S2 and the first flow rate control unit C1 via a wired or wireless communication line so that they can communicate with each other. In this case, the temperature information acquired by the second acquisition unit S2 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature information. The first flow rate control unit C1 then adjusts the valve to an opening corresponding to the received valve opening. This controls the flow rate of the ethanol vapor flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310. Therefore, according to the configuration of this modified example, the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320, can reliably prevent the amount of heat stored from increasing excessively.

[0065] <Third Modification> In the distillation system 1000, the heating device 600 shown in Fig. 4 may be used instead of the heating device 300 shown in Fig. 1. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information of the ethanol vapor in the fourth flow path F4. The heating device 600 of this modification includes a third acquisition unit S3 in the pipe forming the fourth flow path F4, which acquires temperature information corresponding to the temperature of the ethanol vapor flowing through this fourth flow path F4. An example of this third acquisition unit S3 is a thermometer such as a thermocouple.

[0066] Furthermore, the heating device 600 of this modified example includes a first flow control unit C1 instead of the first bypass amount control valve provided at the connection point p1. This first flow control unit C1 controls the flow rate of ethanol vapor flowing through the fourth flow path F4 in accordance with temperature information acquired by the third acquisition unit S3. As shown by the dashed line in FIG. 4 , the first flow control unit C1 has a communication function that can acquire temperature information from the third acquisition unit S3 via wired or wireless communication and a control function that adjusts its own valve opening based on the acquired temperature information. With this configuration, the temperature information acquired by the third acquisition unit S3 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts itself to the required valve opening based on the acquired temperature information. This controls the flow rate of ethanol vapor flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0067] Alternatively, the control device may be connected between the third acquisition unit S3 and the first flow control unit C1 via a wired or wireless communication line so that they can communicate with each other. In this case, the temperature information acquired by the third acquisition unit S3 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow control unit C1 based on the acquired temperature information. The first flow control unit C1 then adjusts its own valve opening to match the received valve opening. This controls the flow rate of the ethanol vapor flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0068] <Fourth Modification> In the distillation system 1000, the heating device 300 shown in Fig. 1 may be replaced with a heating device 700 shown in Fig. 5. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information of the ethanol vapor in the range from leaving the preheater 310 to reaching the entrance of the merging channel F2a. The heating device 700 of this modification includes a fourth acquisition unit S4 that acquires temperature information corresponding to the temperature of the ethanol vapor passing through a joining point p2 between the preheater 310 and the fourth flow path F4 on the second flow path F2. An example of the fourth acquisition unit S4 is a thermometer such as a thermocouple.

[0069] Furthermore, the heating device 700 of this modified example includes a first flow control unit C1 instead of the first bypass amount control valve provided at the connection point p1. This first flow control unit C1 controls the flow rate of ethanol vapor flowing through the fourth flow path F4 in accordance with temperature information acquired by the fourth acquisition unit S4. As shown by the dashed line in FIG. 5 , this first flow control unit C1 has a communication function that can acquire temperature information from the fourth acquisition unit S4 via wired or wireless communication and a control function that adjusts its own valve opening based on the acquired temperature information. With this configuration, the temperature information acquired by the fourth acquisition unit S4 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts itself to the required valve opening based on the acquired temperature information. This controls the flow rate of ethanol vapor flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0070] Alternatively, the control device may be connected between the fourth acquisition unit S4 and the first flow control unit C1 via a wired or wireless communication line so that they can communicate with each other. In this case, the temperature information acquired by the fourth acquisition unit S4 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow control unit C1 based on the acquired temperature information. The first flow control unit C1 then adjusts its own valve opening to match the received valve opening. This controls the flow rate of the ethanol vapor flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0071] <Fifth Modification> In the distillation system 1000, the heating device 300 shown in Fig. 1 may be replaced with a heating device 800 shown in Fig. 6. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information and pressure information of the ethanol vapor flowing through the third flow path F3. The heating device 800 of this modified example is provided with a fifth acquisition unit S5 in the piping forming the third flow path F3, which acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the ethanol vapor before it reaches the preheater 310. An example of this fifth acquisition unit S5 is a combination of a thermometer such as a thermocouple and a pressure gauge equipped with a piezoelectric element.

[0072] Furthermore, the heating device 800 of this modified example includes a first flow control unit C1 instead of the first bypass amount control valve provided at the connection point p1. This first flow control unit C1 controls the flow rate of ethanol vapor flowing through the fourth flow path F4 in accordance with the temperature and pressure information obtained by the fifth acquisition unit S5. As shown by the dashed lines in FIG. 6 , this first flow control unit C1 has a communication function capable of acquiring temperature and pressure information from the fifth acquisition unit S5 via wired or wireless communication, and a control function for automatically adjusting the valve opening based on the acquired temperature and pressure information. With this configuration, the temperature and pressure information acquired by the fifth acquisition unit S5 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts the valve opening to the required level based on the acquired temperature and pressure information. This controls the flow rate of ethanol vapor flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0073] Alternatively, the control device may be connected between the fifth acquisition unit S5 and the first flow rate control unit C1 via a wired or wireless communication line so that they can communicate with each other. In this case, the temperature and pressure information acquired by the fifth acquisition unit S5 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature and pressure information. The first flow rate control unit C1 then adjusts the valve opening accordingly. This controls the flow rate of the ethanol vapor flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4, bypassing the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0074] <Sixth Modification> In the distillation system 1000, the heating device 300 shown in Fig. 1 may be replaced with a heating device 900 shown in Fig. 7. In this modification, the amount of preheating of the ethanol vapor discharged from the compressor 320 to be supplied to the preheater 310 as a preheating source is controlled based on temperature information and pressure information of the ethanol vapor discharged from the compressor 320. The heating device 900 of this modified example is provided with a sixth acquisition unit S6 at the discharge port of the compressor 320 or at a pipe connected thereto, which acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the ethanol vapor immediately after being compressed by the compressor 320. An example of this sixth acquisition unit S6 is a combination of a thermometer such as a thermocouple and a pressure gauge equipped with a piezoelectric element.

[0075] Furthermore, the heating device 900 of this modified example includes a second flow rate control unit C2 that controls the flow rate of the ethanol vapor discharged from the discharge port of the compressor 320 to the third flow path F3 and the fifth flow path F5, based on the temperature information and pressure information obtained by the sixth acquisition unit S6. The second flow rate control unit C2 includes a first valve C21 connected to the piping that forms the third flow path F3 and a second valve C22 connected to the piping that forms the fifth flow path F5. By appropriately synchronously controlling the openings of these paired first and second valves C21 and C22, it is possible to control the flow rate of the ethanol vapor discharged from the discharge port of the compressor 320 to the third flow path F3 and the fifth flow path F5.

[0076] The second flow control unit C2 has a communication function that can acquire temperature information and pressure information from the sixth acquisition unit S6 via wired or wireless communication, and a control function that automatically adjusts the valve openings of the first valve C21 and the second valve C22 based on the acquired temperature information and pressure information. With this configuration, the temperature information and pressure information acquired by the sixth acquisition unit S6 is directly transmitted to the second flow control unit C2. The second flow control unit C2 then adjusts the valve openings of the first valve C21 and the second valve C22 based on the acquired temperature information and pressure information. This controls the flow rate of the ethanol vapor discharged from the outlet of the compressor 320 that flows into the third flow path F3 as a preheating source and the flow rate that flows through the fifth flow path F5 to the sixth flow path F6 toward the reboiler 330.

[0077] Alternatively, the control device may be connected between the sixth acquisition unit S6 and the second flow control unit C2 via a wired or wireless communication line so that they can communicate with each other. In this case, the sixth acquisition unit S6 first transmits the temperature and pressure information it acquires to the control device. The control device then transmits the valve openings of the first valve C21 and the second valve C22 to the second flow control unit C2 based on the acquired temperature and pressure information. The second flow control unit C2 then adjusts the valve openings of the first valve C21 and the second valve C22 based on the acquired temperature and pressure information. This controls the flow rate of the ethanol vapor discharged from the outlet of the compressor 320 to the third flow path F3 as a preheating source and the flow rate of the ethanol vapor that is not directed to the preheater 310 but is directed to the reboiler 330 via the fifth flow path F5 and the sixth flow path F6. Therefore, according to the configuration of this modified example, it is possible to more reliably prevent an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320. In this modification, the flow rates of the ethanol vapor flowing through the third flow path F3 and the fifth flow path F5 are controlled based on temperature and pressure information of the ethanol vapor at the position where it is discharged from the compressor 320. However, the temperature and pressure information of the ethanol vapor may be acquired from the third flow path F3. Alternatively, the flow rates of the ethanol vapor flowing through the third flow path F3 and the fifth flow path F5 may be adjusted based on temperature information of the ethanol vapor flowing through any of the second flow path F2, the combined flow path F2a, or the fourth flow path F4, instead of the ethanol vapor discharged from the compressor 320.

[0078] In the first embodiment and the first to sixth modifications described above, the unit operation system is a distillation system 1000, the fluid supply source and the unit operation apparatus are a distillation column 100, the fluid introduced from the fluid supply source is ethanol vapor, and the fluid to be heated by the heater (heating device 300) is water. However, the present invention is not limited to this embodiment. In the above example, the heating device 300 is used as a heat source when distillation is performed in the distillation column 100. However, instead of distillation, the unit operation fluid may be subjected to at least one of stripping, concentration, drying, and evaporation, and the heating device 300 may be used as a heat source for that purpose. In other words, the fluid introduced from the fluid supply source may be a fluid other than ethanol vapor. Furthermore, the fluid to be heated by the heater (heating device 300) may be a fluid other than water.

[0079] [Second embodiment: carbon dioxide gas recovery system] As a second embodiment of the unit operation system equipped with the heating device of the present invention, a carbon dioxide gas recovery system 2000 shown in Fig. 8 will be described. Next, modified examples of the carbon dioxide gas recovery system 2000 will be described with reference to Figs. 9 to 14. The carbon dioxide gas recovery system 2000 of this embodiment employs a heating device having a configuration equivalent to that of the heating device 300 described in the first embodiment as a heating device that heats the rich absorption liquid that is extracted from the regeneration tower 3 and then reintroduced into the regeneration tower 3. Therefore, in the description of this embodiment, devices that have substantially the same functions / roles as those in the first embodiment will be described using the same product numbers as those used in the first embodiment. On the other hand, devices that have different functions / roles from those in the first embodiment will be described by assigning different symbols.

[0080] 8, the carbon dioxide gas recovery system 2000 of this embodiment includes a carbon dioxide gas recovery device 200 and a heating device 300. Hereinafter, the carbon dioxide gas recovery device 200 will be described first, and then the heating device 300 will be described.

[0081] (1) Carbon dioxide gas recovery device 200 The carbon dioxide gas recovery device 200 of this embodiment recovers carbon dioxide gas from a carbon dioxide-containing gas by absorption and separation using a CO2 chemical absorption separation method, and also generates a decarbonated gas in which carbon dioxide gas is separated from the carbon dioxide-containing gas. This CO2 chemical absorption separation method uses an absorption liquid capable of absorbing carbon dioxide gas. For example, an amine absorption liquid that uses monoethanolamine (MEA) or diethanolamine (DEA) as a solute and water as a solvent can be used as this absorption liquid.

[0082] As shown in FIG. 8, the carbon dioxide gas recovery device 200 includes an absorption tower 2, a regeneration tower 3, a rich absorbent supply path 4, and a lean absorbent supply path 5. The absorption tower 2 brings the carbon dioxide-containing gas into contact with a lean absorbing liquid capable of absorbing carbon dioxide gas, and causes the carbon dioxide gas in the carbon dioxide-containing gas to be absorbed by the lean absorbing liquid to produce a rich absorbing liquid. Meanwhile, the regeneration tower 3 heats the rich absorbing liquid supplied from the absorption tower 2 to separate the carbon dioxide gas from the rich absorbing liquid, thereby regenerating the lean absorbing liquid. The rich absorbing liquid supply path 4 supplies the rich absorbing liquid from the absorption tower 2 to the regeneration tower 3. The lean absorbing liquid supply path 5 supplies the lean absorbing liquid from the regeneration tower 3 to the absorption tower 2.

[0083] An inlet passage 2d for introducing a carbon dioxide-containing gas into the absorption tower 2 is provided at the tower bottom 2a. A first nozzle 7 for supplying a lean absorption liquid downward into the tower is installed in the tower top 2b of the absorption tower 2. An absorption tower intermediate section 2c between the tower top 2b and the tower bottom 2a of the absorption tower 2 contains absorption tower packing 8 for bringing the lean absorption liquid and the carbon dioxide-containing gas into contact with each other on their surfaces. The absorption tower 2 is also provided with an outlet line 9 for discharging the decarbonated gas from the top 2b of the absorption tower 2 to the outside of the tower, and a decarbonated gas cleaning system 10 for discharging the cleaning water (cleaning liquid) stored in the top 2b of the absorption tower 2 from the absorption tower 2, cooling it, and then reintroducing it into the top 2b of the absorption tower 2.

[0084] The decarbonated gas cleaning system 10 includes a liquid receiving tray 11 that is positioned above the first nozzle 7 and stores cleaning water, a second nozzle 12 that is positioned above the liquid receiving tray 11 and supplies cleaning water downward, and piping 13 that connects the liquid receiving tray 11 and the second nozzle 12. The piping 13 is provided with a cleaning water circulation pump 13a that transfers cleaning water from the liquid receiving tray 11 to the second nozzle 12 through the piping 13, and a water-cooled cleaning water cooler 15 that cools the cleaning water downstream of the cleaning water circulation pump 13a. The washing water is preferably the same as the solute of the absorbing liquid (for example, water). Here, the absorbing liquid means a lean absorbing liquid, a rich absorbing liquid, or a mixture of a lean absorbing liquid and a rich absorbing liquid.

[0085] The rich absorbent supply path 4 connects the bottom 2a of the absorption tower 2 and a third nozzle 16 that is disposed in the top 3b of the regeneration tower 3 and supplies the rich absorbent downward. The rich absorbent supply path 4 is provided with an absorber bottom pump 17 that transfers the rich absorbent from the bottom 2a of the absorption tower 2 to the third nozzle 16 through the rich absorbent supply path 4.

[0086] A regeneration tower packing 18 is accommodated in a tower intermediate section 3c between the tower top section 3b and the tower bottom section 3a of the regeneration tower 3. The absorption liquid flowing down the surface of this regeneration tower packing 18 comes into gas-liquid contact with the vapor components of the solute and solvent (e.g., water) of the absorption liquid rising in the regeneration tower 3, and with a mixed gas of this vapor component and carbon dioxide gas.

[0087] The lean absorbent supply path 5 connects the tower bottom 3a of the regenerator 3 and the first nozzle 7 in the absorption tower 2. The lean absorbent supply path 5 is provided with a regenerator bottom pump 35 that transfers the lean absorbent from the tower bottom 3a of the regenerator 3 to the first nozzle 7 via the lean absorbent supply path 5. In addition, an amine heat exchanger 36 that exchanges heat between the lean absorbent and the rich absorbent is interposed between the lean absorbent supply path 5 and the rich absorbent supply path 4.

[0088] (2) Heating device 300 The heating device 300 includes a preheater 310, a compressor 320, a reboiler (heater) 330, a cooler 340, a gas-liquid separator 350A, pipes connecting these components, control valves and pumps (not shown) provided on these pipes, and a control device (not shown). The preheater 310 is a heat exchanger that uses a preheat source to heat the mixed gas (a mixed gas of carbon dioxide gas, the solute of the absorption liquid, and the vapor of the solvent) extracted from the top 3b of the regeneration tower 3. The regeneration tower 3 and the preheater 310 are connected by a pipe that forms a first flow path F1. That is, the upstream end of the first flow path F1 is connected to the top 3b of the regeneration tower 3, and the downstream end of the first flow path F1 is connected to the preheater 310.

[0089] The compressor 320 is a device that compresses the mixed gas preheated by the preheater 310 to further increase the temperature. Generally, compressors are either oil-lubricated or non-oil-lubricated, but for reasons described below, a non-oil-lubricated compressor is used as the compressor 320 of this heating device 300. It is preferable to use electricity derived from renewable energy to drive the compressor 320. In this case, carbon dioxide emissions from the heating device 300 can be reduced.

[0090] The preheater 310 and the suction port of the compressor 320 are connected by a pipe forming a second flow path F2. That is, the upstream end of the second flow path F2 is connected to the preheater 310, and the downstream end of the second flow path F2 is connected to the suction port of the compressor 320. The mixed gas compressed and heated by the compressor 320 is supplied to the preheater 310 via a pipe forming a third flow path F3. That is, an upstream end of the third flow path F3 is connected to the discharge port of the compressor 320, and a downstream end of the third flow path F3 is connected to the preheater 310.

[0091] The first flow path F1 and the second flow path F2 are connected by a pipe forming a fourth flow path F4, which directs a portion or all of the mixed gas flowing through the first flow path F1 to the second flow path F2, bypassing the preheater 310. Specifically, the upstream end of the fourth flow path F4 is connected to a connection point p1 located midway between one end and the other end of the first flow path F1, and the downstream end of the fourth flow path F4 is connected to a connection point p2 located midway between one end and the other end of the second flow path F2. A T-shaped pipe is provided at the connection point p1, connecting the pipe forming the first flow path F1 to the pipe forming the fourth flow path F4. This T-shaped pipe allows the mixed gas flowing through the first flow path F1 to branch into a flow toward the preheater 310 and a flow toward the fourth flow path F4. A flow control valve (not shown) is connected midway between the connection point p1 and the preheater 310 on the pipe forming the first flow path F1. In addition, a flow control valve (not shown) is connected to the piping that forms the fourth flow path F4. Hereinafter, the flow control valve provided in the first flow path F1 and the flow control valve provided in the fourth flow path F4 may be collectively referred to as a first bypass amount control valve.

[0092] The flow control valves provided in the first flow path F1 and the fourth flow path F4 are each electrically connected to the control device. Note that "electrically connected" here is not limited to direct connection by wiring or the like, but also includes connection via a line such as wireless or the Internet. The flow control valve provided in the first flow path F1 adjusts the flow rate of the mixed gas flowing from the first flow path F1 to the preheater 310 in response to instructions from the control device. The flow control valve provided in the fourth flow path F4 adjusts the flow rate of the mixed gas flowing from the first flow path F1 to the second flow path F2 through the fourth flow path F4, which bypasses the preheater 310. By using the first bypass amount control valve, when the total flow rate of the mixed gas flowing through the first flow path F1 is 100%, the proportion of the mixed gas passing through the preheater 310 can be adjusted between 0% and 100%, and the proportion of the mixed gas flowing through the fourth flow path F4 can be adjusted to the remainder (i.e., 100% to 0%) obtained by subtracting the flow rate of the mixed gas flowing through the first flow path F1 from the total flow rate.

[0093] In order to ensure smooth flow of high-temperature fluid, it is preferable to use a steel pipe made of carbon steel or stainless steel for the fourth flow path F4. Since a mixed gas (gas-liquid mixture) flows through the fourth flow path F4, it is more preferable to use a pipe made of stainless steel.

[0094] The reboiler 330 is a heat exchanger that takes in and heats the rich absorption liquid stored in the liquid receiving tray 21 of the regenerator 3. The reboiler 330 uses the heated mixed gas taken in from the preheater 310 (the mixed gas heated by the compressor 320) as its heat source. The preheater 310 and the reboiler 330 are connected by a pipe that forms a sixth flow path F6. That is, the upstream end of the sixth flow path F6 is connected to the preheater 310, and the downstream end of the sixth flow path F6 is connected to the reboiler 330.

[0095] A piping that forms a fifth flow path F5 connects a connection point p3 located midway along the sixth flow path F6 and a connection point p4 located midway along the third flow path F3. A part or all of the heated mixed gas flowing through the third flow path F3 can be diverted via the fifth flow path F5 to the sixth flow path F6 and further to the reboiler 330. That is, a T-shaped pipe is provided at the connection point p4, connecting the pipe from the discharge port of the compressor 320 to the connection point p4, the pipe forming the third flow path F3, and the pipe forming the fifth flow path F5. This T-shaped pipe allows the heated mixed gas discharged from the compressor 320 to branch into a flow toward the third flow path F3 and a flow toward the sixth flow path F6 via the fifth flow path F5. Herein, a flow control valve (not shown) is connected to the pipe forming the third flow path F3. Similarly, a flow control valve (not shown) is also connected to the pipe forming the fifth flow path F5. Hereinafter, the flow control valve provided in the third flow path F3 and the flow control valve provided in the fifth flow path F5 may be collectively referred to as the second bypass amount control valve. The flow control valves provided in the third flow path F3 and the fifth flow path F5 are each electrically connected to the control device. Note that "electrically connected" here does not necessarily mean a direct connection by wiring or the like, but also includes connection via a communication line such as wireless or the Internet. The flow control valve provided in the third flow path F3 adjusts the flow rate of the heated mixed gas that flows from the discharge port of the compressor 320 through the third flow path F3 to the preheater 310 in response to instructions from the control device. The flow control valve provided in the fifth flow path F5 adjusts the flow rate of the heated mixed gas that flows from the discharge port of the compressor 320 through the fifth flow path F5 and bypasses it to the sixth flow path F6.

[0096] With the second bypass flow path control valve, when the total flow rate of the heated mixed gas discharged from the discharge port of the compressor 320 is taken as 100%, the proportion of the heated mixed gas flowing to the preheater 310 can be adjusted between 0% and 100%, and the proportion of the heated mixed gas that bypasses the preheater 310 by passing from the discharge port of the compressor 320 through the fifth flow path F5 can be adjusted to the remainder (i.e., 100% to 0%). In other words, with the second bypass flow path control valve, the proportion of the heated mixed gas that bypasses the preheater 310 by passing through the fifth flow path F5 can be adjusted between 0% and 100%, and the proportion of the heated mixed gas that flows from the discharge port of the compressor 320 to the preheater 310 can be adjusted to the remainder (i.e., 100% to 0%).

[0097] In order to ensure smooth flow of high-temperature and high-pressure fluid, it is preferable to use a steel pipe made of carbon steel or stainless steel for the fifth flow path F5. Since the fifth flow path F5 carries a heated mixed gas (gas-liquid mixture), it is more preferable to use a pipe made of stainless steel.

[0098] The heated mixed gas supplied as a heat source from the sixth flow path F6 to the reboiler 330 heats the rich absorption liquid taken out from the liquid receiving tray 21 of the regenerator 3, and then flows through a pipe forming a seventh flow path F7 to the cooler 340. The reboiler 330 and the cooler 340 are connected by the seventh flow path F7. That is, the upstream end of the seventh flow path F7 is connected to the reboiler 330, and the downstream end of the seventh flow path F7 is connected to the cooler 340.

[0099] The mixed gas flowing from the reboiler 330 to the cooler 340 is cooled in the cooler 340 and then introduced into the gas-liquid separator 350A, where it is separated into condensed liquid and carbon dioxide gas. The cooler 340 and the gas-liquid separator 350A are connected by a pipe forming an eighth flow path F8. That is, the upstream end of the eighth flow path F8 is connected to the cooler 340, and the downstream end of the eighth flow path F8 is connected to the gas-liquid separator 350A. The carbon dioxide gas separated in the gas-liquid separator 350A is discharged from the tenth flow path F10. On the other hand, the condensed liquid (condensed solute and solvent vapor) separated in the gas-liquid separator 350A passes through the ninth flow path F9 and is reintroduced into the regeneration tower 3 from the fourth nozzle 28.

[0100] As described above, the reboiler 330 is a heat exchanger that takes in and heats the rich absorption liquid stored in the liquid receiving tray 21 of the regenerator 3. The outward path between the reboiler 330 and the regenerator 3 is composed of an eleventh flow path F11 and a pump (not shown). That is, the upstream end of the eleventh flow path F11 is connected to the regenerator 3, and the downstream end of the eleventh flow path F11 is connected to the reboiler 330. The return path between the reboiler 330 and the regenerator 3 is connected via a fourteenth flow path F14. That is, the upstream end of the fourteenth flow path F14 is connected to the reboiler 330, and the downstream end of the fourteenth flow path F14 is connected to the lower side of the regenerator 3.

[0101] The operation of the carbon dioxide gas recovery system 2000 having the above-described configuration will be described below. In this explanation, first, the operation mainly of the carbon dioxide gas recovery device 200 will be described, and then the operation mainly of the heating device 300 will be described.

[0102] The flow of the absorbing liquid in the carbon dioxide gas recovery unit 200 will be explained starting from the absorption tower 2. First, in the absorption tower 2, the carbon dioxide-containing gas supplied to the tower bottom 2a rises within the tower, and the lean absorption liquid supplied from the first nozzle 7 in the tower top 2b descends within the tower. During this process, the carbon dioxide-containing gas and the lean absorption liquid come into contact with each other, and the carbon dioxide gas in the carbon dioxide-containing gas is absorbed by the lean absorption liquid.

[0103] As described above, the absorber packing 8 is disposed in the tower middle section 2c of the absorber 2. The absorber packing 8 has, for example, a fin configuration with many narrow gaps, a large fin surface area per volume, and the gaps are configured so that the flow path angle changes regularly, intentionally causing flow turbulence. On the surface of the absorber packing 8, the lean absorbing liquid flows down, forming a wetted wall on the fins, and comes into gas-liquid contact with the carbon dioxide-containing gas rising in the absorber 2. The absorber packing 8 has a structure in which the gaps of the wetted wall are narrow and the advancing angle changes at a constant pitch, thereby turbulenting the gas-liquid flow and improving the efficiency of gas-liquid contact. Therefore, on the surface of the absorber packing 8, the rising carbon dioxide-containing gas and the falling lean absorbing liquid easily come into contact with each other, accelerating the absorption of carbon dioxide gas by the lean absorbing liquid.

[0104] As a result, a rich absorbent and decarbonated gas are produced. Of these, the decarbonated gas rises toward the top 2b of the absorption tower 2 and is discharged to the outside through the discharge path 9. Furthermore, in this embodiment, the absorber 2 is provided with the decarbonated gas scrubbing system 10, and therefore the inside of the tower top 2b of the absorber 2 can be cooled by the wash water cooled by the water-cooled wash water cooler 15 and reintroduced. Therefore, for example, even if solutes in the lean absorption liquid scatter or evaporate and rise together with the decarbonated gas, the solutes are supplied to the decarbonated gas scrubbing system 10 before reaching the outlet line 9. This makes it possible to prevent the solutes in the lean absorption liquid from flowing out from the tower top 2b of the absorber 2 to the outside through the outlet line 9.

[0105] On the other hand, the rich absorbing solution produced together with the decarbonated gas flows down inside the absorption tower 2 and is stored in the tower bottom 2a, and then is supplied to a third nozzle 16 in the tower top 3b of the regeneration tower 3 through a rich absorbing solution supply path 4. Here, an amine heat exchanger 36 is interposed between the lean absorbing solution supply path 5 and the rich absorbing solution supply path 4, and the rich absorbing solution flowing through the lean absorbing solution supply path 5 exchanges heat with the lean absorbing solution flowing through the lean absorbing solution supply path 5, thereby cooling the lean absorbing solution and heating the rich absorbing solution itself.

[0106] In the regeneration tower 3, the rich absorbing liquid supplied from the third nozzle 16 descends within the tower, while the rich absorbing liquid extracted from the liquid receiving tray 21 and heated by the reboiler 330 in a procedure described below is reintroduced into the tower bottom 3a. At this time, part of the heated rich absorbing liquid flashes in the vapor generating section 22, and part of the solute and solvent in the rich absorbing liquid each become vapor, and the regenerated carbon dioxide becomes gas and rises inside the regeneration tower 3. During this process, the rich absorbing liquid comes into contact with the vapor components of the solute and solvent, and an endothermic desorption regeneration reaction occurs using the heat of condensation of the vapor components of the solute and solvent as a heat source, and carbon dioxide gas is separated from the rich absorbing liquid.

[0107] As described above, regenerator packing 18 is disposed in the middle section 3c of the regenerator 3. This regenerator packing 18 has, for example, a fin configuration with many narrow gaps, a large fin surface area per volume, and the gaps are configured so that the flow angle changes regularly, intentionally creating flow turbulence. On the surface of the regenerator packing 18, the rich absorbent flows down, forming a wetted wall on the fins, and comes into contact with the solute and solvent vapors rising inside the regenerator 3. The large surface area and flow turbulence efficiently achieve gas-liquid contact, accelerating the separation and release of carbon dioxide.

[0108] As a result, the rich absorbent is separated into the lean absorbent and carbon dioxide gas. Of these, the carbon dioxide gas is mixed with the solute and the vapor of the solvent to form a mixed gas. This mixed gas rises inside the regeneration tower 3 and flows into the first flow path F1 of the heating device 300.

[0109] Next, the operation of the heating device 300 will be described. First, in the reboiler 330, the rich absorbing liquid stored in the liquid receiving tray 21 of the regenerator 3 is introduced into the reboiler 330 through the eleventh flow path F11, which is the outward path. The introduced rich absorbing liquid flows through heat exchange tubes (not shown) provided in the reboiler 330. Meanwhile, the heated mixed gas compressed and heated by the compressor 320 flows around the outside of the heat exchange tubes, and transfers its heat to the rich absorbing liquid in the heat exchange tubes through the wall surfaces of the heat exchange tubes. As a result, the rich absorbing liquid is heated by the heated mixed gas and becomes a heated fluid. After leaving the reboiler 330, this heated fluid is introduced into the regenerator 3 from the lower side of the regenerator 3 through the fourteenth flow path F14, which is the return path.

[0110] Meanwhile, at the top 3b of the regeneration tower 3, the mixed gas is introduced into the preheater 310 through the first flow path F1. The introduced mixed gas flows through heat exchange tubes (not shown) provided in the preheater 310. Meanwhile, the heated mixed gas, which has been heated by compression in the compressor 320 and is supplied from the third flow path F3, flows outside the heat exchange tubes and transfers its heat to the mixed gas in the heat exchange tubes through the wall surfaces of the heat exchange tubes. In this way, the heated mixed gas, which has been heated by compression in the compressor 320, is used as a preheat source to preheat the mixed gas flowing in the preheater 310. In this way, the heating device 300 of this embodiment uses the heated mixed gas compressed in the compressor 320 as a preheat source, and therefore does not require an external heat source.

[0111] The mixed gas preheated in the preheater 310 is supplied to the compressor 320 through the second flow path F2. The mixed gas is then compressed by the compressor 320, increasing its temperature and pressure to become a heated mixed gas. After reaching the connection point p4, the heated mixed gas is diverted to the third flow path F3 by adjustment of the flow path control valve, but as necessary, a part or all of the heated mixed gas is bypassed to the sixth flow path F6 via the fifth flow path F5 by adjustment of the flow path control valve. This bypass will be described later. First, the heated mixed gas supplied to the third flow path F3 is supplied to the preheater 310 as a preheating source, and heats and raises the temperature of the mixed gas on its way from the first flow path F1 to the second flow path F2. Then, the heated mixed gas that has been preheated in the preheater 310 is supplied to the reboiler 330 through the sixth flow path F6. As described above, in the reboiler 330, the heat of the heated mixed gas supplied from the sixth flow path F6 heats the rich absorption liquid supplied from the liquid receiving tray 21 of the regenerator 3 through the eleventh flow path F11, and then the rich absorption liquid is returned to the tower bottom 3a.

[0112] Meanwhile, the mixed gas supplied to the reboiler 330 from the sixth flow path F6 and having completed its role as a heat source is introduced into the cooler 340 via the seventh flow path F7, cooled, and then flowed to the gas-liquid separator 350A via the eighth flow path F8. In this gas-liquid separator 350A, the mixed gas is separated into carbon dioxide gas and condensate. The separated carbon dioxide gas is then discharged from the tenth flow path F10. The separated condensate passes through the ninth flow path F9 and is reintroduced into the regenerator 3 from the fourth nozzle 28.

[0113] Of the first flow path F1 to the fourteenth flow path F14 described above, both the fourth flow path F4 and the fifth flow path F5 are made of stainless steel pipes, but for the other pipes, if the fluid flowing therethrough is at high temperature and pressure, pipes made of carbon steel or pipes made of stainless steel may also be used. In this case, it is more preferable to use pipes made of carbon steel when the fluid flowing therethrough is only gas, and to use pipes made of stainless steel when the fluid flowing therethrough is liquid or a gas-liquid mixture.

[0114] As described above, compressors are generally classified into oil-lubricated and non-oil-lubricated types, and the compressor 320 of this embodiment is of the non-oil-lubricated type. The reason for this is that if an oil-lubricated compressor is used as the compressor 320, there is a risk that oil mist may be mixed into the heated mixed gas that has passed through the compressor 320. Therefore, an oil-free compressor is adopted, but because its sealing characteristics are inferior to those of an oil-lubricated compressor, another problem arises: it is difficult to increase the compression ratio. Therefore, simply adopting the oil-free compressor 320 would not be able to heat the mixed gas to the required temperature, and this could result in an insufficient heat source to supply to the heater 330. Furthermore, if there is such an insufficient amount of heat, the temperature of the heating fluid supplied to the regenerator 3 would naturally not be sufficient, which could cause problems in the operation of the regenerator 3.

[0115] Therefore, in the heating device 300 of this embodiment, the heated mixed gas, which has been heated by compression in the compressor 320, is supplied to the preheater 310 as a preheating source, and self-thermal regeneration is adopted in which the mixed gas passing through the preheater 310 is preheated using this preheating source. According to this configuration, by raising the temperature of the mixed gas before compression in advance, it is possible to reduce the amount of compression required to raise the temperature to the required temperature at the discharge port of the compressor 320. As a result, the compression ratio required of the compressor 320 is alleviated, and the discharge pressure of the compressor 320 can be reduced. Therefore, it is possible to raise the temperature of the heated mixed gas to the required temperature while lowering the discharge pressure of the compressor 320.

[0116] In addition to such self-heat regeneration, the heating device 300 of this embodiment is characterized by being provided with the fourth flow path F4 and the fifth flow path F5 described above. To explain this, first, the heating device 300 of this embodiment employs self-heat regeneration as described above, and supplies a portion of the heat contained in the heated mixed gas discharged from the compressor 320 via the preheater 310 to the mixed gas before it is taken into the compressor 320. Therefore, a circulation path is formed for the heat flow, in which the heat flows out of the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2, and then returns to the compressor 320. In this circulation path, some heat may be accumulated during the self-heat regeneration process, but the amount of accumulated heat can be reduced by using one or both of the fourth flow path F4 and the fifth flow path F5.

[0117] That is, when the fourth flow path F4 is used, the mixed gas flowing through the first flow path F1 is caused to bypass the preheater 310 and flow through the second flow path F2, thereby reducing or eliminating the amount of heat received by the preheater 310. Therefore, it is possible to prevent an excessive increase in the amount of heat stored in the circulation path. Similarly, when the fifth flow path F5 is used, the heated mixed gas compressed and heated by the compressor 320 can be passed through the sixth flow path F6, bypassing the preheater 310, so that the flow rate of the preheat source supplied to the preheater 310 can be reduced or cut off. This prevents the amount of heat stored in the circulation path from increasing excessively. In this way, when adjusting using the fourth flow path F4, the amount of heat received is limited, and when adjusting using the fifth flow path F5, the amount of heat generated is limited, making it possible to prevent excessive heat accumulation in the circulation path. Either the control of the amount of heat received or the control of the amount of heat generated may be performed, or both may be performed simultaneously. In other words, while the present embodiment illustrates the case where the fourth flow path F4 and the fifth flow path F5 are provided in parallel, this configuration is not limiting. For example, the fifth flow path F5 may be omitted and only the amount of heat received by the fourth flow path F4 may be adjusted, or the fourth flow path F4 may be omitted and only the amount of heat generated by the fifth flow path F5 may be adjusted. Alternatively, as shown in FIG. 8, the fourth flow path F4 and the fifth flow path F5 may be provided in parallel, and the amount of heat received by the fourth flow path F4 and the amount of heat generated by the fifth flow path F5 may be adjusted simultaneously or at appropriate timings.

[0118] In the fourth flow path F4, the flow rate of the mixed gas flowing from the first flow path F1 to the preheater 310 and the flow rate of the mixed gas flowing from the first flow path F1 to the fourth flow path F4 and bypassing the preheater 310 may be appropriately adjusted with reference to the state of the fluid flowing at each position in the circulation path (fluid temperature, fluid pressure). Alternatively, flow path switching control may be performed such that all (100%) of the mixed gas flowing through the first flow path F1 flows to only one of the fourth flow path F4 and the preheater 310 and not the other. Similarly, in the fifth flow path F5, the flow rate of the heated mixed gas flowing through the third flow path F3 and the flow rate of the heated mixed gas bypassing the preheater 310 by flowing through the sixth flow path F6 via the fifth flow path F5 may be appropriately adjusted with reference to the state (fluid temperature, fluid pressure) of the fluid flowing through each position in the heating device 300. Alternatively, flow path switching control may be performed such that all (100%) of the heated mixed gas compressed by the compressor 320 flows through only one of the fifth flow path F5 and the third flow path F3 and not the other. Specific control methods that refer to the state (fluid temperature, fluid pressure) of the fluid flowing through the circulation path will be described later as first to sixth modified examples based on FIGS.

[0119] The essential features of the heating device 300 described above are summarized below. That is, the heating device 300 of this embodiment is The reboiler (heater) 330 uses the mixed gas discharged from the top 3b of the regeneration tower (fluid supply source) 3 as a heating fluid to heat the rich absorption liquid (fluid to be heated) discharged from the liquid receiving tray 21 of the regeneration tower 3, a preheater 310 into which the mixed gas from the top 3b of the regeneration tower 3 is introduced via a first flow path F1; a compressor 320 connected downstream of the preheater 310 via a second flow path F2; a third flow path F3 that supplies at least a portion of the heated mixed gas compressed by the compressor 320 to the preheater 310 as a preheating source; a reboiler 330 into which the heated mixed gas discharged from the third flow path F3 via the preheater 310 is introduced as a heating fluid; Equipped with.

[0120] According to the heating device 300, the mixed gas introduced into the preheater 310 from the top 3b of the regeneration tower 3 via the first flow path F1 is preheated to increase its temperature, and then introduced into the compressor 320 via the second flow path F2. Subsequently, the mixed gas introduced into the compressor 320 is compressed by the compressor 320 to further increase its temperature, and then introduced into the preheater 310 via the third flow path F3. In the preheater 310, the heat of the heated mixed gas introduced via the third flow path F3 is used as a preheat source to preheat the mixed gas traveling from the first flow path F1 to the second flow path F2 toward the compressor 320. Therefore, the temperature of the mixed gas can be increased before being introduced into the compressor 320. As a result, the compressor 320 can reduce the workload of compressing the mixed gas to a temperature required for the heating fluid used in the reboiler 330. Therefore, the compression ratio requirement for the compressor 320 is relaxed, and a non-oil-lubricated compressor 320 can be adopted.

[0121] Furthermore, the heating device 300 of this embodiment has the following features: The gas turbine further includes a fourth flow path F4 that connects the first flow path F1 and the second flow path F2, bypassing the preheater 310. According to this configuration, at least a portion of the mixed gas flowing from the first flow path F1 through the second flow path F2 to the compressor 320 can be passed through the fourth flow path F4 as needed, allowing the mixed gas to flow to the compressor 320 without being preheated by the preheater 310. Therefore, by adjusting the flow rate of the mixed gas flowing through the fourth flow path F4 and bypassing the preheater 310 as needed, the temperature of the mixed gas supplied to the compressor 320 can be controlled to an appropriate temperature. That is, the heat of the heated mixed gas heated by the compressor 320 travels downstream of the compressor 320, passes through the third flow path F3 to the preheater 310, is supplied to the mixed gas preheated by the preheater 310, and returns to the compressor 320. However, by using the fourth flow path F4, which bypasses the preheater 310, the amount of preheating can be reduced or eliminated. This reduces heat accumulation before and after the compressor 320.

[0122] Furthermore, the heating device 300 of this embodiment has the following features: The system further includes a fifth flow path F5 that connects the downstream side of the compressor 320 and the reboiler 330 via a sixth flow path F6. According to this configuration, the heated mixed gas after being heated by the compressor 320 can be sent to the reboiler 330 via the fifth flow path F5 and the sixth flow path F6, allowing for more flexible control of the preheating of the mixed gas introduced into the compressor 320. For example, by flowing at least a portion of the heated mixed gas after being heated by the compressor 320 through the fifth flow path F5, the amount of heated mixed gas sent to the preheater 310 can be reduced. This allows for the amount of preheating to be kept low or no preheating to be performed at all. This makes it possible to suppress heat accumulation in the circulation path.

[0123] The carbon dioxide gas recovery system 2000 of this embodiment is as follows: an absorption tower 2 into which a gas to be separated containing carbon dioxide gas is introduced and brought into contact with a lean absorption liquid, and the carbon dioxide gas in the gas to be separated is absorbed by the lean absorption liquid to produce a rich absorption liquid; a regeneration tower 3 that receives a rich absorbing solution from the absorption tower 2, and heats the rich absorbing solution to separate carbon dioxide gas from the rich absorbing solution and regenerate it into a lean absorbing solution; a heating device 300 for heating the rich absorption liquid that is being discharged from the regeneration tower 3 and reintroduced into the regeneration tower 3; Equipped with The fluid supply source that causes the mixed gas to flow through the first flow path F1 is the regeneration tower 3, the fluid introduced from the fluid supply source is a mixed gas of the carbon dioxide gas and the solute and solvent vapor components of the rich absorption liquid, which is discharged from the regeneration tower 3; The fluid to be heated is the absorption liquid. According to this configuration, recovery of carbon dioxide gas and generation of decarbonated gas can be performed without using a heat source such as steam in the reboiler 330.

[0124] Furthermore, in the carbon dioxide gas recovery system 2000 of this embodiment, The compressor 320 may be powered by electricity derived from renewable energy. In this case, by using electricity derived from renewable energy as the power source for the compressor 320, it is possible to further enhance the effect of reducing the environmental load in addition to the effect of self-heat regeneration.

[0125] <First Modification> In the carbon dioxide gas recovery system 2000, a heating device 400 shown in Fig. 9 may be adopted instead of the heating device 300 shown in Fig. 8. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information and pressure information of the heated mixed gas discharged from the compressor 320. The heating device 400 of this modified example is provided with a first acquisition unit S1 at the discharge port of the compressor 320 or at a pipe connected thereto, which acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the heated mixed gas immediately after being compressed by the compressor 320. An example of this first acquisition unit S1 is a combination of a thermometer such as a thermocouple and a pressure gauge equipped with a piezoelectric element.

[0126] Furthermore, the heating device 400 of this modification includes a first flow rate control unit C1 instead of the first bypass amount control valve provided downstream of the connection point p1. This first flow rate control unit C1 controls the flow rate of the mixed gas flowing through the fourth flow path F4 in accordance with the temperature and pressure information acquired by the first acquisition unit S1. As shown by the dashed lines in FIG. 9 , the first flow rate control unit C1 has a communication function capable of acquiring the temperature and pressure information from the first acquisition unit S1 via wired or wireless communication and a control function for adjusting its own valve opening based on the acquired temperature and pressure information. With this configuration, the temperature and pressure information acquired by the first acquisition unit S1 is directly transmitted to the first flow rate control unit C1. The first flow rate control unit C1 then adjusts its own valve opening to the required value based on the acquired temperature and pressure information. This controls the flow rate of the mixed gas flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0127] Alternatively, the control device may be communicatively connected between the first acquisition unit S1 and the first flow rate control unit C1 via a wired or wireless communication line. In this case, the temperature and pressure information acquired by the first acquisition unit S1 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature and pressure information. The first flow rate control unit C1 then adjusts the valve opening accordingly. This controls the flow rate of the mixed gas flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 that bypasses the preheater 310. Therefore, according to the configuration of this modified example, it is possible to reliably prevent an excessive increase in the amount of heat stored in the heat circulation path described above, which exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2, and then returns to the compressor 320.

[0128] <Second Modification> In the carbon dioxide gas recovery system 2000, a heating device 500 shown in Fig. 10 may be adopted instead of the heating device 300 shown in Fig. 8. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information of the mixed gas before the suction port of the compressor 320. In the heating device 500 of this modified example, a second acquisition unit S2 that acquires temperature information corresponding to the temperature of the mixed gas immediately before being compressed by the compressor 320 is provided on a pipe that forms a junction flow path F2a formed between the junction point p2, which is the junction point of the second flow path F2 with the fourth flow path F4, and the intake port of the compressor 320. An example of this second acquisition unit S2 is a thermometer such as a thermocouple.

[0129] Furthermore, the heating device 500 of this modification includes a first flow control unit C1 instead of the first bypass amount control valve provided downstream of the connection point p1. This first flow control unit C1 controls the flow rate of the mixed gas flowing through the fourth flow path F4 in accordance with the temperature information acquired by the second acquisition unit S2. As shown by the dashed line in FIG. 10 , the first flow control unit C1 has a communication function capable of acquiring temperature information from the second acquisition unit S2 via wired or wireless communication and a control function for adjusting its own valve opening based on the acquired temperature information. With this configuration, the temperature information acquired by the second acquisition unit S2 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts itself to the required valve opening based on the acquired temperature information. This controls the flow rate of the mixed gas flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0130] Alternatively, the control device may be communicatively connected between the second acquisition unit S2 and the first flow rate control unit C1 via a wired or wireless communication line. In this case, the temperature information acquired by the second acquisition unit S2 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature information. The first flow rate control unit C1 then adjusts the valve to an opening corresponding to the received valve opening. This controls the flow rate of the mixed gas flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 that bypasses the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0131] <Third Modification> In the carbon dioxide gas recovery system 2000, a heating device 600 shown in Fig. 11 may be adopted instead of the heating device 300 shown in Fig. 8. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information of the mixed gas in the fourth flow path F4. The heating device 600 of this modification includes a third acquisition unit S3 in the pipe forming the fourth flow path F4, which acquires temperature information corresponding to the temperature of the mixed gas flowing through this fourth flow path F4. An example of this third acquisition unit S3 is a thermometer such as a thermocouple.

[0132] Furthermore, the heating device 600 of this modification includes a first flow rate control unit C1 instead of the first bypass amount control valve provided at the connection point p1. This first flow rate control unit C1 controls the flow rate of the mixed gas flowing through the fourth flow path F4 in accordance with the temperature information acquired by the third acquisition unit S3. As shown by the dashed line in FIG. 11 , the first flow rate control unit C1 has a communication function capable of acquiring temperature information from the third acquisition unit S3 via wired or wireless communication and a control function for adjusting its own valve opening based on the acquired temperature information. With this configuration, the temperature information acquired by the third acquisition unit S3 is directly transmitted to the first flow rate control unit C1. The first flow rate control unit C1 then adjusts itself to the required valve opening based on the acquired temperature information. This controls the flow rate of the mixed gas flowing through the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310.

[0133] Alternatively, the control device may be communicatively connected between the third acquisition unit S3 and the first flow rate control unit C1 via a wired or wireless communication line. In this case, the temperature information acquired by the third acquisition unit S3 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature information. The first flow rate control unit C1 then adjusts the valve opening accordingly. This controls the flow rate of the mixed gas flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 that bypasses the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0134] <Fourth Modification> In the carbon dioxide gas recovery system 2000, a heating device 700 shown in Fig. 12 may be employed instead of the heating device 300 shown in Fig. 8. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information of the mixed gas in the range from when it leaves the preheater 310 to when it reaches the entrance of the merging flow path F2a. The heating device 700 of this modified example includes a fourth acquisition unit S4 that acquires temperature information corresponding to the temperature of the mixed gas passing through a position between the heated fluid outlet of the preheater 310 and the connection point p2, which is the joining and connection point of the second flow path F2 with the fourth flow path F4. An example of this fourth acquisition unit S4 is a thermometer such as a thermocouple.

[0135] Furthermore, the heating device 700 of this modification includes a first flow control unit C1 instead of the first bypass amount control valve provided at the connection point p1. The first flow control unit C1 controls the flow rate of the mixed gas flowing through the fourth flow path F4 in accordance with the temperature information acquired by the fourth acquisition unit S4. As shown by the dashed line in FIG. 12 , the first flow control unit C1 has a communication function capable of acquiring temperature information from the fourth acquisition unit S4 via wired or wireless communication and a control function for adjusting its own valve opening based on the acquired temperature information. With this configuration, the temperature information acquired by the fourth acquisition unit S4 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts itself to the required valve opening based on the acquired temperature information. This controls the flow rate of the mixed gas flowing through the first flow path F1 that is directed to the preheater 310 and the flow rate that is directed to the fourth flow path F4 that bypasses the preheater 310.

[0136] Alternatively, the control device may be communicatively connected between the fourth acquisition unit S4 and the first flow control unit C1 via a wired or wireless communication line. In this case, the temperature information acquired by the fourth acquisition unit S4 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow control unit C1 based on the acquired temperature information. The first flow control unit C1 then adjusts the valve opening accordingly. This controls the flow rate of the mixed gas flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0137] <Fifth Modification> In the carbon dioxide gas recovery system 2000, a heating device 800 shown in Fig. 13 may be adopted instead of the heating device 300 shown in Fig. 8. In this modification, the amount of preheating in the preheater 310 is controlled based on temperature information and pressure information of the heated mixed gas flowing through the third flow path F3. The heating device 800 of this modified example includes a fifth acquisition unit S5 in the piping forming the third flow path F3, which acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the heated mixed gas before it reaches the preheater 310. An example of this fifth acquisition unit S5 is a combination of a thermometer such as a thermocouple and a pressure gauge equipped with a piezoelectric element.

[0138] Furthermore, the heating device 800 of this modification includes a first flow control unit C1 instead of the first bypass amount control valve provided at the connection point p1. This first flow control unit C1 controls the flow rate of the mixed gas flowing through the fourth flow path F4 in accordance with the temperature and pressure information obtained by the fifth acquisition unit S5. As shown by the dashed lines in FIG. 13 , this first flow control unit C1 has a communication function capable of acquiring the temperature and pressure information from the fifth acquisition unit S5 via wired or wireless communication, and a control function for automatically adjusting the valve opening based on the acquired temperature and pressure information. With this configuration, the temperature and pressure information acquired by the fifth acquisition unit S5 is directly transmitted to the first flow control unit C1. The first flow control unit C1 then adjusts the valve opening to the required level based on the acquired temperature and pressure information. This controls the flow rate of the mixed gas flowing through the first flow path F1 that is directed to the preheater 310 and the flow rate that is directed to the fourth flow path F4 and bypasses the preheater 310.

[0139] Alternatively, the control device may be connected between the fifth acquisition unit S5 and the first flow rate control unit C1 via a wired or wireless communication line so that they can communicate with each other. In this case, the temperature and pressure information acquired by the fifth acquisition unit S5 is first transmitted to the control device. The control device then transmits the required valve opening to the first flow rate control unit C1 based on the acquired temperature and pressure information. The first flow rate control unit C1 then adjusts the valve opening accordingly. This controls the flow rate of the mixed gas flowing from the first flow path F1 that is directed toward the preheater 310 and the flow rate that is directed toward the fourth flow path F4 and bypasses the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320.

[0140] <Sixth Modification> In the carbon dioxide gas recovery system 2000, a heating device 900 shown in Fig. 14 may be employed instead of the heating device 300 shown in Fig. 8. In this modification, based on temperature information and pressure information of the heated mixed gas discharged from the compressor 320, the preheat amount of the heated mixed gas discharged from the compressor 320 to be supplied to the preheater 310 as a preheat source is controlled. The heating device 900 of this modified example is provided with a sixth acquisition unit S6 at the discharge port of the compressor 320 or at a pipe connected thereto, which acquires temperature information corresponding to the temperature and pressure information corresponding to the pressure of the heated mixed gas immediately after being compressed by the compressor 320. An example of this sixth acquisition unit S6 is a combination of a thermometer such as a thermocouple and a pressure gauge equipped with a piezoelectric element.

[0141] Furthermore, the heating device 900 of this modified example includes a second flow rate control unit C2 that controls the flow rate of the heated mixed gas discharged from the discharge port of the compressor 320 to the third flow path F3 and the fifth flow path F5 in accordance with the temperature information and pressure information obtained by the sixth acquisition unit S6. The second flow rate control unit C2 includes a first valve C21 connected to the piping that forms the third flow path F3 and a second valve C22 connected to the piping that forms the fifth flow path F5. By appropriately synchronously controlling the openings of these paired first valve C21 and second valve C22, the flow rate of the heated mixed gas discharged from the discharge port of the compressor 320 to the third flow path F3 and the fifth flow path F5 can be controlled.

[0142] The second flow control unit C2 has a communication function that can acquire temperature information and pressure information from the sixth acquisition unit S6 via wired or wireless communication, and a control function that automatically adjusts the valve openings of the first valve C21 and the second valve C22 based on the acquired temperature information and pressure information. With this configuration, the temperature and pressure information acquired by the sixth acquisition unit S6 is directly transmitted to the second flow control unit C2. The second flow control unit C2 then adjusts the valve openings of the first valve C21 and the second valve C22 based on the acquired temperature and pressure information. This controls the flow rate of the heated mixed gas discharged from the discharge port of the compressor 320 to flow through the third flow path F3 as a preheating source and the flow rate of the heated mixed gas to flow through the fifth flow path F5 to the sixth flow path F6 toward the reboiler 330.

[0143] Alternatively, the control device may be communicatively connected between the sixth acquisition unit S6 and the second flow control unit C2 via a wired or wireless communication line. In this case, the sixth acquisition unit S6 first transmits the acquired temperature and pressure information to the control device. The control device then transmits the valve openings of the first valve C21 and the second valve C22 to the second flow control unit C2 based on the acquired temperature and pressure information. The second flow control unit C2 then adjusts the valve openings of the first valve C21 and the second valve C22 based on the acquired temperature and pressure information. This controls the flow rate of the heated mixed gas discharged from the discharge port of the compressor 320 to the third flow path F3 as a preheating source and the flow rate of the heated mixed gas to be directed to the reboiler 330 via the fifth flow path F5 and the sixth flow path F6 without being directed to the preheater 310. Therefore, the configuration of this modified example reliably prevents an excessive increase in the amount of heat stored in the heat circulation path described above, in which the heat exits the compressor 320, passes through the third flow path F3, the preheater 310, and the second flow path F2 before returning to the compressor 320. In this modification, the flow rates of the heated mixed gas flowing through the third flow path F3 and the fifth flow path F5 are controlled based on temperature and pressure information of the heated mixed gas at the position where it is discharged from the compressor 320. However, the temperature and pressure information of the heated mixed gas may be acquired from the third flow path F3. Alternatively, the flow rates of the heated mixed gas flowing through the third flow path F3 and the fifth flow path F5 may be adjusted based on temperature information of the mixed gas flowing through any of the second flow path F2, the combined flow path F2a, and the fourth flow path F4, instead of the heated mixed gas discharged from the compressor 320. [Explanation of symbols]

[0144] 2. Absorption tower 3 Regeneration tower (fluid supply source) 100 Distillation column (unit operation equipment) 200 Carbon dioxide gas recovery equipment (unit operation equipment) 300 Heating device 310 Preheater 320 Compressor 330 Reboiler (heater) 340 Cooler 350 Branch 360 Branch 400 Heating device (first modified example) 500 Heating device (second modified example) 600 Heating device (third modified example) 700 Heating device (fourth variant) 800 Heating device (5th variant) 900 Heating device (sixth variant) 1000 Distillation System (Unit Operation System) 2000 Carbon dioxide gas recovery system (unit operation system) C1 First flow control section C2 Second flow control section F1 First flow path F2 Second flow path F2a convergence road F3 Third flow path F4 Fourth flow path F5 5th flow path F6 6th flow path S1, S5 Acquisition Part 1 S2 Acquisition Part 2 S3 Acquisition Part 3 S4 Acquisition Part 4 S6 Acquisition Part 5

Claims

1. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fourth flow path connecting the first flow path and the second flow path while bypassing the preheater; a first acquisition unit that acquires temperature information corresponding to a temperature and pressure information corresponding to a pressure of the fluid flowing through the third flow path or the fluid compressed by the compressor; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information and the pressure information; A heating device comprising:

2. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fourth flow path connecting the first flow path and the second flow path while bypassing the preheater; Equipped with the second flow path includes a confluence flow path that merges the fluid discharged from the downstream side of the preheater and the fluid flowing through the fourth flow path and introduces the merged fluid into the upstream side of the compressor, a second acquisition unit that acquires temperature information corresponding to a temperature of the fluid flowing through the merging channel; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information; The heating device further comprises:

3. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fourth flow path connecting the first flow path and the second flow path while bypassing the preheater; a third acquisition unit that acquires temperature information corresponding to a temperature of the fluid flowing through the fourth flow path; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information; A heating device comprising:

4. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fourth flow path connecting the first flow path and the second flow path while bypassing the preheater; Equipped with the second flow path includes a confluence flow path that merges the fluid discharged from the downstream side of the preheater and the fluid flowing through the fourth flow path and introduces the merged fluid into the upstream side of the compressor, a fourth acquisition unit that acquires temperature information corresponding to a temperature of the fluid downstream of the preheater and before the fluid reaches the junction; a first flow rate control unit that controls a flow rate of the fluid flowing through the fourth flow path in accordance with the temperature information; The heating device further comprises:

5. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fourth flow path connecting the first flow path and the second flow path while bypassing the preheater; a fifth flow path connecting the downstream side of the compressor and the heater; A heating device comprising:

6. a fifth acquisition unit that acquires temperature information corresponding to a temperature and pressure information corresponding to a pressure of the fluid flowing within a range downstream of the compressor and upstream of the third flow path; a second flow rate control unit that controls a flow rate of the fluid flowing from the downstream side of the compressor to the third flow path and a flow rate of the fluid flowing from the downstream side of the compressor to the fifth flow path in accordance with the temperature information and the pressure information; The heating device according to claim 5, further comprising:

7. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fifth flow path connecting the downstream side of the compressor and the heater; a first acquisition unit that acquires temperature information corresponding to a temperature and pressure information corresponding to a pressure of the fluid flowing within a range downstream of the compressor and upstream of the third flow path; a second flow rate control unit that controls a flow rate of the fluid flowing from the downstream side of the compressor to the third flow path and a flow rate of the fluid flowing from the downstream side of the compressor to the fifth flow path in accordance with the temperature information and the pressure information; A heating device comprising:

8. An apparatus for heating a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; a fifth flow path connecting the downstream side of the compressor and the heater; a second acquisition unit that acquires temperature information corresponding to a temperature of the fluid before compression that flows into the compressor; a second flow rate control unit that controls a flow rate of the fluid flowing from the downstream side of the compressor to the third flow path and a flow rate of the fluid flowing from the downstream side of the compressor to the fifth flow path in accordance with the temperature information; A heating device comprising:

9. The compressor is driven by electricity derived from renewable energy. The heating device according to any one of claims 1 to 8.

10. The heating device according to any one of claims 1 to 8, A unit operation system characterized by comprising a unit operation device that performs at least one of distillation, stripping, concentration, drying, and evaporation on a unit operation fluid using the heated fluid heated by the heater.

11. The compressor is driven by electricity derived from renewable energy. The unit operation system according to claim 10.

12. an absorption tower that introduces a gas to be separated containing carbon dioxide gas and a lean absorption liquid into the gas to be separated, and causes the carbon dioxide gas in the gas to be separated to be absorbed by the lean absorption liquid to produce a rich absorption liquid; a regeneration tower to which the rich absorbing liquid is supplied from the absorption tower and which heats the rich absorbing liquid to separate the carbon dioxide gas and thereby regenerate the rich absorbing liquid into the lean absorbing liquid; a heating device that heats the rich absorption liquid while it is being withdrawn from the regeneration tower and reintroduced into the regeneration tower; Equipped with The heating device is the heating device according to any one of claims 1 to 8, the fluid supply source is the regeneration tower, the fluid introduced from the fluid supply source is a mixed gas of the carbon dioxide gas and the solute and solvent vapor components of the rich absorption liquid, which is discharged from the regeneration tower; The heated fluid is the rich absorption liquid. A carbon dioxide gas recovery system characterized by:

13. The compressor is driven by electricity derived from renewable energy.

13. The carbon dioxide gas recovery system according to claim 12.

14. an absorption tower that introduces a gas to be separated containing carbon dioxide gas and a lean absorption liquid into the gas to be separated, and causes the carbon dioxide gas in the gas to be separated to be absorbed by the lean absorption liquid to produce a rich absorption liquid; a regeneration tower to which the rich absorbing liquid is supplied from the absorption tower and which heats the rich absorbing liquid to separate the carbon dioxide gas and thereby regenerate the rich absorbing liquid into the lean absorbing liquid; a heating device that heats the rich absorption liquid while it is being withdrawn from the regeneration tower and reintroduced into the regeneration tower; Equipped with The heating device is a device that heats a fluid to be heated by a heater that uses a fluid introduced from a fluid supply source as a heating fluid, a preheater into which the fluid from the fluid supply is introduced via a first flow path; a compressor connected to the downstream side of the preheater via a second flow path; a third flow path that supplies at least a portion of the fluid compressed by the compressor to the preheater as a preheating source; the heater that introduces the fluid that has been discharged from the third flow path through the preheater as the heating fluid and heats the fluid to be heated; Equipped with the fluid supply source is the regeneration tower, the fluid introduced from the fluid supply source is a mixed gas of the carbon dioxide gas and the solute and solvent vapor components of the rich absorption liquid, which is discharged from the regeneration tower; The heated fluid is the rich absorption liquid. A carbon dioxide gas recovery system characterized by:

15. The compressor is driven by electricity derived from renewable energy.

15. The carbon dioxide gas recovery system according to claim 14.

16. The carbon dioxide gas recovery system according to claim 14 or 15, characterized in that the heating device further comprises a fourth flow path that connects the first flow path and the second flow path, bypassing the preheater.

17. The carbon dioxide gas recovery system according to claim 14 or 15, characterized in that the heating device further comprises a fifth flow path connecting between the downstream side of the compressor and the heater.

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