WO2013114936A1

WO2013114936A1 - Distillation device and distillation method

Info

Publication number: WO2013114936A1
Application number: PCT/JP2013/050496
Authority: WO
Inventors: 堤　敦司; 堤　香津雄
Original assignee: 国立大学法人東京大学; エクセルギー工学研究所株式会社
Priority date: 2012-02-01
Filing date: 2013-01-12
Publication date: 2013-08-08
Also published as: JP5756900B2; JPWO2013115073A1; JPWO2013114936A1; WO2013115073A1; WO2013114937A1

Abstract

The present invention addresses the problem of improving the exergy rate (∆G/∆H) and minimizing thermal energy that is wastefully disposed of. To this end, developed is a distillation device provided with: a distillation column which receives and distills an input fluid containing a plurality of substances; a compressor which compresses a first output fluid that has come out of the top of the distillation column; a first heat exchanger which heats the input fluid by the first output fluid that has come out of the compressor; and a second heat exchanger which heats the input fluid by a second output fluid that has come out of the bottom of the distillation column.

Description

Distillation apparatus and distillation method

The present invention relates to a distillation apparatus and a distillation method using a self-regenerative technology of a working medium, and more particularly, to a distillation apparatus and a distillation method in which the waste heat is suppressed and the exergy rate of the entire system is improved.

Conventionally, various plants have been proposed for power generation devices and heating devices. In a steam plant, fuel is burned in a boiler to generate steam, and this steam is guided to a steam turbine, and a generator is driven to generate electric power (see, for example, Patent Document 1). The steam exiting the steam turbine is led to a condenser where it is condensed and returned to water. Seawater is often used as the refrigerant that condenses steam.

The gas turbine compresses natural gas to a high pressure and burns it with a combustor to generate a high-temperature and high-pressure combustion gas. And combustion gas is guide | induced to a gas turbine, a generator is driven, and electric power is generated. The exhaust gas exiting the gas turbine is guided to a steam generator and then released to the atmosphere (see, for example, Patent Document 2).

The diesel engine burns liquid fuel inside the engine and the generator is driven by the generated power to generate electricity. Exhaust gas emitted from the diesel engine may be led to a steam generator to recover its energy, but is finally released to the atmosphere (see, for example, Patent Document 3).

JP 2003-269113 A JP 2004-022230 A JP 2008-115723 A

A prime mover represented by a steam turbine, a gas turbine, and a diesel engine obtains drive power by burning a working fluid. In the prime mover, the heat energy of the working fluid is finally discarded. That is, in the steam turbine, the latent heat of the exhaust steam is discarded by the condenser. In gas turbines and diesel engines, exhaust gas is finally discharged into the atmosphere and cannot be said to be used sufficiently effectively.

(1. Conventional multi-effect evaporator)
The conventional multi-effect evaporator 110 shown in FIG. 1B employs a cascade utilization method in which each evaporator is operated at a different pressure and the latent heat of vaporization is used as the latent heat of vaporization of the next can.

The input fluid sequentially flows into the evaporators 111, 112, and 113, and the output fluid that is a gas is sequentially output from the top of the evaporators 111, 112, and 113. At this time, the evaporator 111 is a heating source and functions as a boiler.

The output fluid that has come out from the top of the evaporators 111 and 112 flows into the evaporators 112 and 113 in the next stage, heats the evaporators 112 and 113, and is then discarded. Finally, the output fluid, which is a liquid output from the bottom of the evaporator 113, is collected from the pipe 115. On the other hand, the output fluid from the top of the third evaporator 113 is recovered by being cooled by the cooler 114.

Thus, in the multi-effect evaporator 110, most of the heat (energy) heated is thrown out of the system as low-temperature waste heat after heating the evaporator.

(2. Conventional flash distillation equipment)
The conventional flash distillation apparatus 120 shown in FIG. 2B uses a mixed liquid of 50% benzene and 50% toluene as an input fluid a. This input fluid a is heated in the heating furnace 126 and introduced into the flash column 127. A vapor b1 containing a large amount of benzene, which is a low-boiling component, and a liquid b2 containing a large amount of toluene are obtained from the top of the flash column 127.

The steam b1 emitted from the top of the flash column 127 is heat-exchanged with the input fluid a by the first heat exchanger 124 and then cooled by the cooler 128 to be liquefied. The liquid b2 exiting from the bottom of the flash column 127 is recovered after heat exchange with the input fluid a in the second heat exchanger 125.

In the example of FIG. 2B, sensible heat of 120 kW is recovered by the

first heat exchanger

124 and 131 kW is recovered by the second heat exchanger 125, respectively. However, the heating furnace 126 requires 488 kW of latent heat.

(3. Conventional seawater desalination plant)
A conventional seawater desalination plant 130 shown in FIG. 3B is an example of a seawater desalination plant using a multistage flash method.

The input fluid a, which is seawater, passes through the plurality of heat exchangers 131, is heated by the heater 133, and flows into the endmost flash drum 132. The input fluid a flowing into the flash drum 132 is separated into a steam b1 output from the top of the flash drum 132 and a liquid c1 output from the bottom of the flash drum 132.

These operations are performed in a plurality of stages, and the steam bn emitted from the top of each flash drum 132 is finally cooled by the cooler 134 and recovered as fresh water as a product. On the other hand, the liquid cn discharged from the bottom of the flash drum 132 is finally cooled by the cooler 135 and recovered as a by-product.

This conventional seawater desalination plant 130 needs to be reheated by the heater 133. The applied heat is finally thrown out of the system as low-temperature waste heat.

(4. Conventional bioethanol azeotropic distillation equipment)
The conventional bioethanol azeotropic distillation apparatus (hereinafter abbreviated as azeotropic distillation apparatus) shown in FIG. 4B uses azeotropic distillation using benzene as an azeotropic agent. In the azeotropic distillation apparatus 140, a benzene-water mixture is taken out from the top of the first rectifying column 141, and high-purity ethanol is taken out from the bottom of the first rectifying column 141. The benzene-water mixture taken out from the top of the first rectifying column 141 is separated into benzene and water by the first decanter 143 and the second rectifying column 142. Benzene is recycled to the first rectification column 141 for reuse. However, the azeotropic distillation apparatus 140 consumes a large amount of energy. Under the conditions shown in FIG. 4B, the

heaters

145 and 146 of the two rectification towers 141 and 142 require a large amount of energy of 395 kW in total.

When taking out electric power using a chemical reaction, if the original energy of the fuel is ΔH, ΔG can be taken out as electricity and TΔS can be taken out as heat. ΔG is energy that can be taken out as work, and is called exergy as effective energy. TΔS is heat generated with the reaction. And ΔG / ΔH is called the exergy rate as the ability to extract effective energy. The exergy rate is the rate converted to reversible energy. However, the rate of conversion to reversible energy when heat is generated decreases, and the exergy rate decreases.

An object of the present invention is to solve the above-described problems, and is to improve the exergy rate ΔG / ΔH. In other words, it is an object of the present invention to provide an apparatus and method for minimizing wasteful thermal energy.

In order to solve the above-described problems, a distillation apparatus according to the present invention includes a distillation column that receives and distills an input fluid containing a plurality of substances, and a compressor that compresses a first output fluid discharged from the top of the distillation column. A first heat exchanger that heats the input fluid by the first output fluid that has exited from the compressor, and a second heat fluid that heats the input fluid by a second output fluid that has exited from the bottom of the distillation column. Two heat exchangers.

This configuration heats the input fluid by exchanging heat between the output fluid heated by adiabatic compression and the input fluid, so that energy is not wasted. A plant or apparatus with a high exergy rate can be realized. The input fluid is preferably a liquid.

The distillation apparatus according to the present invention further includes a heater disposed inside the distillation column, and the heater heats the distillation column with the first output fluid output from the compressor, The first heat exchanger is preferably provided downstream of the heater.

According to this configuration, the heat of the output fluid raised in temperature by adiabatic compression can be effectively used for heating the distillation tower.

In the distillation apparatus according to the present invention, it is preferable that the second heat exchanger heats the input fluid with the second output fluid and the first output fluid output from the first heat exchanger.

The distillation apparatus according to the present invention includes a first branch channel that leads a part of the input fluid to the first heat exchanger, a second branch channel that guides the other part of the input fluid to the second heat exchanger, It is preferable to further include a merging unit that merges the input fluid that has passed through the first and second exchangers.

The distillation apparatus according to the present invention further includes a third heat exchanger disposed between the compressor and the junction, and the third heat exchanger receives the input fluid after passing through the junction. The first output fluid is preferably heated.

The distillation apparatus according to the present invention further includes a fourth heat exchanger disposed between the compressor and the second heat exchanger, and the fourth heat exchanger includes the second heat exchanger. It is preferable that the second output fluid before flowing into the tank is heated by the first output fluid.

The distillation apparatus according to the present invention is disposed downstream of the first heat exchanger and is disposed downstream of the first cooler into which the first output fluid flows and the second heat exchanger, and into which the second output fluid flows. And a second cooler.

In the distillation apparatus according to the present invention, the input fluid is a mixed substance containing a low-boiling substance and a high-boiling substance, the first output fluid contains a low-boiling substance, and the second output fluid Preferably contains a substance having a high boiling point.

In the distillation apparatus according to the present invention, it is preferable that the input fluid contains salt, and the salt concentration of the first output fluid is lower than that of the input fluid. In this configuration, the input fluid is preferably seawater and the first output fluid is fresh water.

A distillation apparatus according to the present invention includes a first distillation column to which a first input fluid containing a first substance, a second input fluid containing a second substance and a third substance are supplied, and a tower of the first distillation tower A first compressor that compresses the first output fluid that has exited from the top, and a first output fluid that heats the second output fluid that has exited from the bottom of the first distillation column by the first output fluid that has exited from the compressor. A heat exchanger, a second distillation column into which the first output fluid from the first heat exchanger flows, and a second compressor for compressing the third output fluid from the top of the second distillation column. And the third output fluid from the second compressor heats the fourth output fluid from the bottom of the second distillation column and directs the third output fluid to the second distillation column. Separating the first substance from the second heat exchanger to be discharged and the first output fluid exiting from the first heat exchanger, A decanter for returning one substance to the first distillation column, a first outlet for recovering the second substance contained in the second input fluid coming out from the bottom of the first distillation column, It is preferable to have a second outlet for recovering the third substance contained in the second input fluid that has come out of the tower bottom. Further, the distillation apparatus according to the present invention includes a third compressor that compresses a part of the third output fluid that has come out from the top of the second distillation column, and a first substance in which the first substance is separated by the decanter. A third heat exchanger that heats the input fluid with the third output fluid exiting from the third compressor and discharges the third output fluid toward the first distillation column; Preferably it is.

According to this configuration, since the input fluid is heated by exchanging heat between the output fluid heated by adiabatic compression and the input fluid, energy is not wasted. A plant or apparatus with a high exergy rate can be realized.

The distillation apparatus according to the present invention preferably further includes a first cooler disposed between the first heat exchanger and the decanter for cooling the first output fluid.

In the distillation apparatus according to the present invention, it is preferable that the first substance is benzene, the second substance is ethanol, and the third substance is water.

The distillation method according to the present invention includes a separation step of separating an input fluid into vapor and liquid, a compression step of compressing the vapor, and a first heating step of heating the input fluid with the compressed vapor. And a second heating step for heating the input fluid with the liquid and a liquefaction step for liquefying the steam used in the first heating step.

According to this method, a part or all of the heating step or the combustion step is a step of adiabatically compressing the output fluid from the separation unit and using this as a heating source to exchange heat with the input fluid before flowing into the separation unit By substituting, loss of heat energy with a low exergy rate accompanying heating or combustion can be suppressed. Thereby, TΔS can be decreased, ΔG can be increased, and the exergy rate ΔG / ΔH can be improved.

As described above, according to the present invention, it is possible to provide a distillation apparatus and a distillation apparatus method in which the energy loss is suppressed and the exergy rate ΔG / ΔH is improved.

It is a schematic diagram which shows schematic structure of the distillation apparatus of Embodiment 1 of this invention. 1 is a schematic diagram showing a schematic configuration of a conventional technique of Embodiment 1. FIG. It is a schematic diagram which shows schematic structure of the distillation apparatus of Embodiment 2 of this invention. FIG. 6 is a schematic diagram showing a schematic configuration of a conventional technique of Embodiment 2. It is a schematic diagram which shows schematic structure of the distillation apparatus of Embodiment 3 of this invention. FIG. 6 is a schematic diagram showing a schematic configuration of a conventional technique of Embodiment 3. It is a schematic diagram which shows schematic structure of the distillation apparatus of Embodiment 4 of this invention. FIG. 10 is a schematic diagram illustrating a schematic configuration of a conventional technique of a fourth embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

<Embodiment 1>
The self-heating regenerative distillation apparatus 10 of Embodiment 1 shown in FIG. 1A includes an inlet 11 serving as an inlet for raw materials (input fluid), a first outlet 16 serving as an outlet for products (output fluid), and a second outlet 17. have. Various devices are connected between the introduction port 11 and the first and

second discharge ports

16 and 17 by piping. For example, the output fluid as a product is collected from the first discharge port 16, and the waste liquid is collected from the second discharge port 17. That is, the input fluid includes a plurality of substances, and among these substances, a substance having a low boiling point is recovered from the first outlet 16 and the remaining substance is recovered from the second outlet 17.

The self-heat regeneration distillation apparatus 10 has two heat exchangers, one compressor, and one evaporator. That is, the second heat exchanger 12 exchanges heat between the input fluid A and the second output fluid B2 that has exited the first heat exchanger 13. The first heat exchanger 13 exchanges heat between the input fluid A exiting the second heat exchanger 12 and the first output fluid B1 exiting from the evaporator heating tube 14A.
The compressor 15 adiabatically compresses the first output fluid B1 that has come out from the top of the evaporator 14. The first output fluid B1 is heated by being adiabatically compressed. The evaporator 14 receives the input fluid A that has exited the first heat exchanger 13 and discharges the second output fluid B2 from the bottom of the tower. Note that a heating tube 14 A is disposed inside the evaporator 14.

Hereinafter, the configuration of the self-heat regeneration distillation apparatus 10 will be described along the flow of the input fluid. The input fluid A passes through the second heat exchanger 12 and the first heat exchanger 13 from the inlet 11 and flows into the evaporator 14. The input fluid A exiting the first heat exchanger 13 is separated into a gaseous first output fluid B1 and a liquid second output fluid B2 by the evaporator 14.

The first output fluid B1 coming out from the top of the evaporator 14 is adiabatically compressed by the compressor 15 and flows into the heating tube 14A passing through the inside of the evaporator 14. The first output fluid B1 exchanges heat with the input fluid in the evaporator 14 while passing through the heating tube. The temperature of the input fluid in the evaporator 14 rises. The first output fluid B1 exiting the heating tube 14A flows to the first heat exchanger 13, and the sensible heat is exchanged with the input fluid A exiting the second heat exchanger 12. Thereby, the temperature of the input fluid A rises. The first output fluid B1 that has exited the first heat exchanger 13 flows to the second heat exchanger 12, and the input fluid A and sensible heat are heat-exchanged. The first output fluid B1 that has exited the second heat exchanger 12 is recovered from the first outlet 16.

On the other hand, the second output fluid B2 that has come out from the bottom of the evaporator 14 flows into the second heat exchanger 12. While the second output fluid B2 passes through the second heat exchanger 12, the input fluid A and sensible heat are heat-exchanged. The second output fluid B2 is recovered from the second outlet 17 after leaving the second heat exchanger 12.

Thus, the input fluid A is heated by the first output fluid B1 and the second output fluid B2 and the sensible heat by the first heat exchanger 13 and the second heat exchanger 12 and heated to the evaporator 14. Inflow. The reason why the first output fluid B1 exchanges sensible heat in two stages in the first heat exchanger 13 and the second heat exchanger 12 is that the temperature in the first heat exchanger 13 is compressed. This is because the temperature compressed by the machine 15 is higher than the temperature when it flows out of the evaporator 14. That is, more heat energy can be recovered by exchanging the heat energy of the first output fluid B1 in two stages.

As described above, the heat held by the first output fluid B1 and the second output fluid B2 is used for heating the input fluid, so that it is not necessary to separately heat with a boiler or the like. That is, the latent heat of these fluids and the self heat of sensible heat are circulated and utilized, and the self heat regeneration distillation apparatus 10 can realize energy saving.

<Embodiment 2>
The flash distillation apparatus 20 of Embodiment 2 shown in FIG. 2A has an inlet 21 that serves as an inlet for raw materials (input fluid), and a first outlet 35 and a second outlet 36 that serve as outlets for products (output fluid). is doing. Various devices are connected by piping between the introduction port 21, the first discharge port 35, and the second discharge port 36. In the output fluid as a product, for example, a component having a low boiling point in the input fluid is recovered from the first discharge port 35, and a component having a high boiling point is recovered from the second discharge port 36.

The flash distillation apparatus 20 has four heat exchangers, one compressor, and one flash column. That is, the first heat exchanger 27 performs heat exchange between the first branch channel 23 and the first recovery channel 37. The second heat exchanger 28 exchanges heat between the second branch channel 24 and the second recovery channel 38. The third heat exchanger 29 exchanges heat between the combined flow path 26 and the first recovery path 37. The fourth heat exchanger 30 exchanges heat between the first recovery path 37 and the second recovery path 38.
The compressor 31 is a first recovery path 37 and is disposed between the top of the flash column 32 and the fourth heat exchanger 30.

Hereinafter, the configuration of the flash distillation apparatus 20 will be described along the flow of the working fluid. The input fluid A flows in from the introduction port 21, and is divided into the first input fluid A 1 that flows through the first branch channel 23 and the second input fluid A 2 that flows through the second branch channel 24 at the branching unit 22. The first input fluid A 1 is heated by the first heat exchanger 27 and flows into the joining portion 25. The second input fluid A 2 is heated by the second heat exchanger 28 and flows into the junction 25. In the merging portion 25, the first input fluid A1 and the second input fluid A2 merge (hereinafter, the merged input fluid is referred to as the input fluid A3).

The input fluid A3 is heated by the third heat exchanger 29 arranged in the combined flow path 26 and flows into the flash column 32. In the flash column 32, the input fluid A3 is separated into a gas first output fluid B1 and a liquid second output fluid B2. The first output fluid B1 flowing out from the top of the flash column 32 flows out from the first outlet 35 via the first recovery path 37. The second output fluid B2 flowing out from the bottom of the flash column 32 flows out from the second discharge port 36 via the second recovery path 38.

The first output fluid B1 is adiabatically compressed by the compressor 31 and rises in temperature. The first output fluid B1 sequentially passes through the fourth heat exchanger 30, the third heat exchanger 29, and the first heat exchanger 27. The first output fluid B1 flowing through the first recovery path 37 heats the second output fluid B2 flowing through the second recovery path 38 while passing through the fourth heat exchanger 30. Heat exchange by latent heat is performed. Further, when the first output fluid B1 passes through the third heat exchanger 29, the first output fluid B1 heats the input fluid A3 flowing through the combined flow path 26, and passes through the first heat exchanger 27 while passing through the first split flow path 23. The flowing first input fluid A1 is heated. The first output fluid B1 is cooled by the first cooler 52, liquefied, and then recovered from the first discharge port 54. The recovered first output fluid B1 is fresh water.

On the other hand, the second output fluid B2 sequentially passes through the fourth heat exchanger 30 and the second heat exchanger 28. The second output fluid B 2 flowing through the second recovery path 38 heats the first output fluid B 1 while passing through the fourth heat exchanger 30, and the second input while passing through the second heat exchanger 28. Heat fluid A2. Heat exchange by sensible heat is performed in the

heat exchangers

28 and 30. The second output fluid B2 is recovered from the second discharge port 36 after being cooled by the second cooler 34. In addition, if the temperature and pressure of each fluid in the inlet 21, the first outlet 35, and the second outlet 36 are the same, the flash distillation apparatus 20 can be easily modularized. The flash distillation apparatus 20 can be used for fractional distillation of benzene and toluene. Moreover, it can be used for distillation of shochu. A plurality of flash distillation apparatuses 20 can be combined to obtain a desired degree of shochu.

Thus, the input fluid A is heated by the first output fluid B1 and the second output fluid B2 in the first heat exchanger 27, the second heat exchanger 28, and the third heat exchanger 29, and is supplied to the flash column 32. Will flow in. The reason why the first output fluid B1 is heat-exchanged in three stages by the first heat exchanger 27, the third heat exchanger 29, and the fourth heat exchanger 30 is that the first heat exchanger 27 is the fourth heat exchanger. This is because the latent heat is exchanged at 30 and the sensible heat is exchanged at the third heat exchanger 29 and the first heat exchanger 27. That is, more energy can be recovered by exchanging the heat energy of the first output fluid B1 in three stages.

As described above, a flash distillation apparatus that does not need to be heated in a heating furnace is realized by using the self-heat of the input fluid A, the first output fluid B1, and the second output fluid B2. Taking FIG. 2B as an example, the 488 kW heating furnace 126 is not necessary. Of course, power is required to drive the compressor 31, but this power is 45.1 kW for an input fluid A of 100 kgmol / h. That is, since the latent heat and sensible heat of the working fluid are circulated and used, the flash distillation apparatus 20 by self-heat regeneration is about 1/11 in terms of enthalpy compared to the conventional flash distillation apparatus 120, and is less than 1/10. It is possible to drive with the energy.

<Embodiment 3>
The desalination plant 40 of Embodiment 3 shown in FIG. 3A has an inlet 41 serving as an inlet for raw materials (input fluid), a first outlet 54 and a second outlet 55 serving as outlets for a product (output fluid). is doing. Various devices are connected by piping between the inlet 41 and the first outlet 54 and the second outlet 55. For example, the desalination plant 40 separates certain components from the input fluid and discharges them from the first discharge port 54, and discharges the separated input fluid from the second discharge port 55.

The desalination plant 40 has three heat exchangers, one compressor, and one flash column. That is, the first heat exchanger 47 exchanges heat between the first branch channel 43 and the first recovery channel 57. The second heat exchanger 48 exchanges heat between the second branch channel 44 and the second recovery channel 58. The third heat exchanger 49 exchanges heat between the combined flow path 46 and the first recovery path 57.
The compressor 50 is a first recovery path 57 and is disposed between the top of the flash column 51 and the third heat exchanger 49.

Hereinafter, the structure of the desalination plant 40 is demonstrated along the flow of a working fluid.
The input fluid A flows in from the introduction port 41, and is divided into the first input fluid A 1 that flows through the first branch channel 43 and the second input fluid A 2 that flows through the second branch channel 44 at the branching unit 42. The first input fluid A1 is heated by the first heat exchanger 47 and flows into the junction 45. The second input fluid A2 is heated by the second heat exchanger 48 and flows into the junction 45. In the merging portion 45, the first input fluid A1 and the second input fluid A2 merge (hereinafter, the merged input fluid is referred to as an input fluid A3).

The input fluid A3 is heated by the third heat exchanger 49 arranged in the combined flow path 46 and flows into the flash column 51. In the flash column 51, the input fluid A3 is separated into a gas first output fluid B1 and a liquid second output fluid B2. The first output fluid B1 that has exited from the top of the flash column 51 flows out from the first outlet 54 via the first recovery path 57. The second output fluid B2 that has exited from the bottom of the flash column 51 flows out from the second outlet 55 via the second recovery path 58. Specifically, the first output fluid B1 is water vapor, and the second output fluid B2 is seawater with a high salinity concentration.

The first output fluid B1 is adiabatically compressed by the compressor 50 to save temperature. The first output fluid B1 sequentially passes through the third heat exchanger 49 and the first heat exchanger 47. The first output fluid B1 flowing through the first recovery path 57 heats the input fluid A3 flowing through the combined flow path 46 when passing through the third heat exchanger 49. Heat exchange by latent heat is performed. And when passing the 1st heat exchanger 47, the 1st input fluid A1 which flows through the 1st distribution path 43 is heated. Heat exchange by sensible heat is performed. The first output fluid B1 is cooled and liquefied by the first cooler 52, and then collected from the first outlet 54. The collected first output fluid B1 is fresh water as a product.

On the other hand, the second output fluid B2 passes through the second heat exchanger 48. The second output fluid B2 heats the second input fluid A2 while passing through the second heat exchanger 48. In the second heat exchanger 48, heat exchange by sensible heat is performed. Then, the second output fluid B 2 is cooled by the second cooler 53 and discharged from the second discharge port 55.

As described above, the input fluid A is heated by the first heat exchanger 47, the second heat exchanger 48, and the third heat exchanger 49 by exchanging heat with the first output fluid B1 and the second output fluid B2. , Flows into the flash column 51. The reason why the first output fluid B1 is heat-exchanged in two stages in the first heat exchanger 47 and the third heat exchanger 49 is that the latent heat is first exchanged in the third heat exchanger 49, Next, it is for recovering more energy by exchanging sensible heat with the first heat exchanger 47.

As described above, since the seawater desalination plant 40 uses the self-heat of the input fluid A, the first output fluid B1, and the second output fluid B2, it is not necessary to heat with a heater. That is, the latent heat and sensible heat of these fluids are recycled. The seawater desalination plant 40 can realize energy saving. In addition, although power is required to drive the compressor 50, the power becomes energy of 67.70 kJ per unit mass of fresh water as a product. However, the seawater desalination plant 130 requires 765.3 kJ of energy per unit mass of fresh water as a product. Therefore, the seawater desalination plant 40 by self-heat regeneration can be operated at about 1/10 of the energy required for the conventional seawater desalination plant 130 by the multistage flash method. A large energy saving effect can be expected.

<Embodiment 4>
An autothermal regeneration bioethanol azeotropic distillation apparatus (hereinafter abbreviated as an azeotropic distillation apparatus) 60 of Embodiment 4 shown in FIG. 4A is composed of benzene, an ethanol-water mixture, high-concentration ethanol and high-purity water. It is a device to take out. There are two

inlets

61 and 62 that serve as inlets for the raw material (input fluid), and two

outlets

78 and 79 that serve as outlets for the product (output fluid). Various devices are connected between the

introduction ports

61 and 62 and the

discharge ports

78 and 79 by piping.

The azeotropic distillation apparatus 60 has three heat exchangers, three compressors, and two rectification columns. That is, all the three

compressors

68, 69, and 70 adiabatically compress the fluid that has exited from the tops of the rectifying columns 63 and 64. The first heat exchanger 65 and the second heat exchanger 67 exchange heat between the fluid exiting from the bottoms of the rectifying columns 63 and 64 and the fluid exiting the

compressors

68 and 69, respectively. The third heat exchanger 66 exchanges heat between the fluid that has exited the decanter 77 and the fluid that has exited the second compressor 70.

The configuration of the azeotropic distillation apparatus 60 will be described along the flow of the input fluid.
A first input fluid A1 containing benzene as a main component and a second input fluid A2 that is an ethanol-water mixture flow into the first fractionator 63 from the first inlet 61 and the second inlet 62, respectively. These two fluids are mixed in the first rectification column 63. Then, the first output fluid B1 is output from the top of the first rectifying column 63, and the second output fluid B2 is output from the bottom of the first rectifying column 63. Here, the first output fluid B1 is a benzene-water mixture, and the second output fluid B2 is high purity ethanol.

A part of the second output fluid B2 exiting from the bottom of the first rectifying column 63 is recovered from the first discharge port 78, and the rest is heated by the first heat exchanger 65 to be first rectifying column. Return to 63.

On the other hand, the first output fluid B1 coming out from the top of the first rectifying column 63 is adiabatically compressed by the first compressor 68 and then passes through the first heat exchanger 65. The output fluid is heated by adiabatic compression. In the first heat exchanger 65, the first output fluid B1 serves as a heating source, and the second output fluid B2 is heated. The first output fluid B1 that has exited the first heat exchanger 65 is decompressed by the first valve 71, cooled by the first cooler 74, and then flows into the decanter 77.

The decanter 77 separates the first output fluid B1 into a fifth output fluid B5 mainly composed of water and a sixth output fluid B6 mainly composed of benzene. The sixth output fluid B6 that has exited the decanter 77 is returned to the first rectifying column 63.

The fifth output fluid B5 is heated in the third heat exchanger 66 and flows into the second rectification column 64. On the other hand, the third output fluid B3, which is a benzene-water mixture containing water as a main component, is output from the top of the second rectifying column 64, and is high-purity water from the bottom of the second rectifying column 64. The fourth output fluid B4 is output.

A part of the fourth output fluid B4 exiting from the bottom of the second rectifying column 64 is recovered from the second outlet 79, and the rest passes through the second heat exchanger 67 to pass through the second rectifying column. Return to 64.

Also, the third output fluid B3 coming out from the top of the second rectification column 64 is divided and flows into the

compressors

69 and 70, respectively. That is, one of the divided third output fluids B3 is adiabatically compressed by the second compressor 69, passes through the second heat exchanger 67, is decompressed by the second valve 72, and is cooled by the second cooler 75. Return to the second rectification tower 64. The other divided third output fluid B3 is adiabatically compressed by the third compressor 70, passes through the third heat exchanger 66, is decompressed by the third valve 73, is cooled by the third cooler 76, and is cooled. Return to Ichidometo 63.

In this way, high-concentration ethanol is recovered from the first outlet 78, and high-purity water is recovered from the second outlet 79.

As described above, the azeotropic distillation apparatus 60 does not need to be heated by the heater by using the self-heat of the input fluid and the output fluid. That is, the latent heat and sensible heat of these fluids are circulated and used, and the azeotropic distillation apparatus 60 can realize energy saving. In the azeotropic distillation apparatus 60, power is required to drive the

compressors

68, 69, and 70. Under the conditions of FIG. 4A, the power is 48.7 kW in total. On the other hand, under the conditions shown in FIG. 4B, a total of 395 kW of energy is required by the

heaters

145 and 146 of the two rectifying columns 141 and 142. Therefore, the azeotropic distillation apparatus 60 of FIG. 4A can be operated with about 1/8 of the energy required for the conventional azeotropic distillation apparatus 140.

<Other embodiments>
The distillation apparatus according to the present invention is an energy-saving method for suppressing exergy loss due to heating or combustion, and makes effective the self-heating of the input fluid in part or all of the heating step or the combustion step of applying heat from the outside. Instead of the reversible energy conversion process used, the ratio of energy that can be used effectively is increased to increase the exergy rate.

According to this configuration, part or all of the heating process or the combustion process can be replaced with a reversible energy conversion process, so that the loss of heat energy having a low exergy rate associated with the heating or combustion can be suppressed. Thereby, TΔS is decreased, ΔG is increased, and the exergy rate ΔG / ΔH is improved as compared with the conventional case. Here, the reversible energy conversion step refers to, for example, a step of changing to energy that can be taken out as work such as gas compression / expansion.

As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention.

The distillation apparatus using the self-heat regeneration technology according to the present invention can be suitably used not only as a distillation apparatus but also as a desalination plant and an azeotropic distillation apparatus.

DESCRIPTION OF SYMBOLS 10 Self-heat regeneration distillation apparatus 11 Inlet 12 Second heat exchanger 13 First heat exchanger 14 Evaporator 14A Heating tube 15 Compressor 20 Flash distillation apparatus 21 Inlet 22 Divider 23 First shunt 24 Second shunt 25 merging section 26 merging channel 27 first heat exchanger 28 second heat exchanger 29 third heat exchanger 30 fourth heat exchanger 31 compressor 32 flash column 33 first cooler 34 second cooler 37 first recovery Path 38 Second recovery path 40 Seawater desalination plant 41 Inlet 42 Diverging section 43 First shunt path 44 Second shunt path 45 Merging section 46 Merging path 47 First heat exchanger 48 Second heat exchanger 49 Third heat exchange 50 Compressor 51 Flash column 52 First cooler 53 Second cooler 57 First recovery path 58 Second recovery path 60 Bioethanol azeotropic distillation device 61 First inlet 62 Second inlet 63 First precision Column 64 Second rectification column 65 First heat exchanger 66 Third heat exchanger 67 Second heat exchanger 68 First compressor 69 Second compressor 70 Third compressor 74 First cooler 75 Second cooler 76 Third cooler 77 Decanter

Claims

A distillation column for receiving and distilling an input fluid containing a plurality of substances;
A compressor for compressing a first output fluid that has exited from the top of the distillation column;
A first heat exchanger that heats the input fluid with the first output fluid exiting the compressor;
A second heat exchanger that heats the input fluid with a second output fluid exiting from the bottom of the distillation column,
Distillation equipment.
Further comprising a heater disposed inside the distillation column;
The distillation according to claim 1, wherein the heater heats the distillation column with the first output fluid output from the compressor, and the first heat exchanger is provided downstream of the heater. apparatus.
The distillation apparatus according to claim 2, wherein the second heat exchanger heats the input fluid by the second output fluid and the first output fluid that has exited from the first heat exchanger.
A first branch channel for leading a part of the input fluid to the first heat exchanger;
A second branch channel for guiding the other part of the input fluid to the second heat exchanger;
The distillation apparatus according to claim 1, further comprising a merging unit that merges the input fluid that has passed through the first and second exchangers.
Further comprising a third heat exchanger disposed between the compressor and the junction.
The distillation apparatus according to claim 4, wherein the third heat exchanger heats the input fluid after passing through the merging portion with the first output fluid.
Further comprising a fourth heat exchanger disposed between the compressor and the second heat exchanger;
The distillation apparatus according to claim 5, wherein the fourth heat exchanger heats the second output fluid before flowing into the second heat exchanger with the first output fluid.
A first cooler disposed downstream of the first heat exchanger and into which the first output fluid flows;
The distillation apparatus according to claim 4, further comprising a second cooler disposed downstream of the second heat exchanger and into which the second output fluid flows.
The input fluid is a mixed substance containing a low-boiling substance and a high-boiling substance, the first output fluid contains a low-boiling substance, and the second output fluid contains a high-boiling substance. The distillation apparatus according to claim 7.
The distillation apparatus according to claim 7, wherein the input fluid contains salt, and the salt concentration of the first output fluid is lower than that of the input fluid.
A first distillation column supplied with a first input fluid containing a first substance and a second input fluid containing a second substance and a third substance;
A first compressor for compressing a first output fluid that has exited from the top of the first distillation column;
A first heat exchanger that heats the second output fluid exiting from the bottom of the first distillation column with the first output fluid exiting from the compressor;
A second distillation column into which the first output fluid from the first heat exchanger flows;
A second compressor for compressing a third output fluid that has exited from the top of the second distillation column;
The third output fluid exiting from the second compressor heats the fourth output fluid exiting from the bottom of the second distillation tower and discharges the third output fluid toward the second distillation tower. A second heat exchanger;
A decanter that separates the first material from the first output fluid exiting the first heat exchanger and returns the first material to the first distillation column;
A first outlet for recovering a second substance contained in a second input fluid that has exited from the bottom of the first distillation column;
A second outlet for recovering a third substance contained in the second input fluid that has exited from the bottom of the second distillation column,
Distillation equipment.
A third compressor that compresses a portion of the third output fluid that has exited from the top of the second distillation column;
The first input fluid from which the first substance is separated by the decanter is heated by the third output fluid that has exited from the third compressor, and the third output fluid is discharged toward the first distillation column. A third heat exchanger,
The distillation apparatus according to claim 10.
The distillation apparatus according to claim 11, further comprising a first cooler disposed between the first heat exchanger and the decanter for cooling the first output fluid.
The distillation apparatus according to claim 11, wherein the first substance is benzene, the second substance is ethanol, and the third substance is water.
Separating the input fluid into vapor and liquid;
A compression step of compressing the vapor;
A first heating step of heating the input fluid with the compressed steam;
A second heating step of heating the input fluid with the liquid;
Liquefying the vapor used in the first heating step,
Distillation method.