Distillation apparatus

Abstract

To provide a distillation apparatus capable of obtaining high distillation treatment efficiently while achieving energy saving, decarbonization and CO2 reduction.SOLUTION: The distillation apparatus 1 comprises a heat pump type steam generating part 20 for generating heated steam by heating reboiler drain water as drain water of a reboiler circulation water for heating a reboiler 13 by a heat source of condenser drain water as drain water of a column bottom part 11 and taking out a low boiling point component from a column top part 12 as a distillate and taking out a high boiling point component from the column bottom part 11 as a drain water.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a distillation apparatus that can achieve high distillation processing efficiency while achieving energy conservation, decarbonization, and CO2 reduction. [Background technology]

[0002] A typical distillation apparatus uses a distillation column used to separate components with different boiling points contained in a feed liquid, with the feed liquid at the bottom of the column heated by a reboiler, high-boiling components extracted from the top of the column, cooled in a condenser and extracted as a distillate, and low-boiling components extracted from the bottom of the column as a bottom product.

[0003] Conventional distillation apparatuses use steam supplied from a boiler as the heat source for the reboiler. However, in order to save energy, decarbonize, and reduce CO2, a system has been disclosed in which heated hot water generated by a heat pump using waste hot water from cooling water supplied to a condenser is used as the heat source for the reboiler (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7044458 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the distillation apparatus described in Patent Document 1 is configured with a heat circulation heating system in which a heat pump using waste hot water from a condenser as a heat source generates heated hot water, which serves as a heat source for a reboiler. However, since the heat source supplied from the heat pump to the reboiler is heated hot water, it is not possible to obtain a high distillation processing efficiency compared to the steam heat source supplied to the reboiler by a conventional boiler.

[0006] The present invention has been made in view of the above, and aims to provide a distillation apparatus that can achieve high distillation processing efficiency while achieving energy conservation, decarbonization, and CO2 reduction. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the distillation apparatus of the present invention is a distillation apparatus which supplies a feed liquid containing components with different boiling points to a distillation column, heats the feed liquid at the bottom of the column using a reboiler, cools the low boiling point components in a condenser from the top of the column and extracts them as a distillate, and extracts the high boiling point components as a bottoms liquid from the bottom of the column, and is characterized by comprising a heat pump type steam generating unit which uses condenser discharge hot water, which is a discharge hot water of condenser circulating water that cools the condenser, as a heat source to heat reboiler discharge hot water, which is a discharge hot water of reboiler circulating water that heats the reboiler, to generate heated steam and supply the heated steam to the reboiler.

[0008] In addition, in the distillation apparatus according to the present invention, in the above invention, the heat pump type steam generation unit has a steam separator that heats the reboiler waste hot water using a condenser and separates the heated reboiler waste hot water, which is gas-liquid two-phase water, into saturated steam and hot water, and circulates the hot water from the steam separator to the condenser side.

[0009] In addition, the distillation apparatus according to the present invention is characterized in that, in the above invention, a condenser-side storage tank is provided between the condenser and the heat pump type steam generation unit, and the condenser discharge hot water is stored in the condenser-side storage tank.

[0010] Furthermore, the distillation apparatus according to the present invention is characterized in that, in the above invention, a reboiler-side storage tank is provided between the reboiler and the heat pump type steam generating unit, and the reboiler waste hot water is stored in the reboiler-side storage tank.

[0011] In addition, the distillation apparatus of the present invention is characterized in that, in the above invention, the distillation column is provided with a temperature sensor that detects the temperature inside the distillation column, and the heat pump type steam generation unit controls the supply of the heated steam based on the temperature detected by the temperature sensor so that the temperature inside the distillation column is between the low boiling point temperature of the low boiling point component and the high boiling point temperature of the high boiling point component. [Effects of the Invention]

[0012] According to the present invention, high distillation processing efficiency can be achieved while energy saving, decarbonization, and CO2 reduction are achieved. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a distillation apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0015] 1 is a schematic diagram showing the configuration of a distillation apparatus 1 according to an embodiment of the present invention. The distillation apparatus 1 includes a distillation column 10, a reboiler 13, a condenser 14, and a heat pump-type vapor generation section 20. A feed liquid containing components with different boiling points is supplied to the distillation column 10, the feed liquid at the column bottom 11 is heated by the reboiler 13, the low boiling point component is removed from the column top 12 by the condenser 14, and the high boiling point component is removed from the column bottom 11 as a bottom product, and a distillation process is performed to separate the low boiling point component from the high boiling point component.

[0016] The reboiler 13 heats the supply liquid circulating in the distillation column 10 with heated steam from the reboiler circulating water supplied from the heat pump steam generating section 20 via the pipe L1. The reboiler discharge hot water that has been heated and condensed from the supply liquid is returned to the heat pump steam generating section 20 via the pipe L2 and then circulates as heated steam. The reboiler 13 may be disposed inside the distillation column 10.

[0017] Condenser 14 cools the low boiling point components using condenser circulating water supplied from heat pump steam generating section 20 via pipe L3 as cooling water, and stores the condensed low boiling point components in receiver 15, after which it sends out the distillate and also refluxes a portion of it as reflux liquid to distillation column 10. The condenser circulating water cooled in condenser 14 is returned to heat pump steam generating section 20 via pipe L4 as condenser discharge hot water, and after heat recovery, is circulated again as cooling water via pipe L3 and supplied to condenser 14.

[0018] The heat pump type steam generating unit 20 has a heat pump unit 30 and a steam generating unit 40. The heat pump unit 30 forms a heat pump cycle in which a compressor 32 that compresses a refrigerant, a condenser 33 that condenses the refrigerant compressed by the compressor 32 through heat exchange with reboiler waste hot water, an expansion valve 34 that is an expansion mechanism that reduces the pressure of the refrigerant condensed by the condenser 33, and an evaporator 31 that evaporates the refrigerant expanded by the expansion valve 34 using heat recovered from the condenser waste hot water, are connected in a ring shape.

[0019] The steam generating section 40 supplies the reboiler waste hot water to the condenser 33, heats this reboiler waste hot water with the refrigerant of the condenser 33, and performs thermosiphon circulation in which the hot water is merged with the reboiler waste hot water via a steam separator 41 that separates the heated reboiler waste hot water, which is gas-liquid two-phase water, into saturated steam and hot water and circulates the merged hot water, and supplies the saturated steam via the steam separator 41 to the reboiler 13 as heated steam. This heated steam is supplied to the reboiler 13 via a pressure regulating valve V40.

[0020] The reboiler waste hot water in pipe L2 is stored in storage tank 52, which is a reboiler-side storage tank, and then supplied to the condenser 33 side via pump P2. The condenser waste hot water in pipe L4 is stored in storage tank 51, which is a condenser-side storage tank, and then supplied to the evaporator 31 side via pump P1. These storage tanks 51 and 52 are buffer tanks provided to absorb the difference in flow rate before and after the storage tanks 51 and 52. The heat exchanger 53 is a heat exchanger that releases excess thermal energy to the outside to achieve heat balance.

[0021] The control unit C controls the operation of the heat pump unit 30 and the steam generation unit 40. The control unit C controls the rotation speed of the compressor 32 and the aperture of the expansion valve 34 based on the outlet refrigerant temperature and outlet refrigerant pressure of the evaporator 31, the temperature of the hot water discharged at the inlet of the evaporator 31, the inlet refrigerant temperature and inlet refrigerant pressure as well as the outlet refrigerant temperature and outlet pressure of the compressor 32, the inlet refrigerant temperature and inlet refrigerant pressure as well as the outlet refrigerant temperature and outlet pressure of the condenser 33, and the outlet refrigerant temperature and outlet pressure of the expansion valve 34. The control unit C also adjusts the aperture of the pressure regulating valve V40 based on the temperature and pressure of the heated steam output from the water vapor separator 41, so that the temperatures detected by the temperature sensors T1 and T2 in the distillation column 10 are between the temperatures of the low-boiling-point components and the high-boiling-point components.

[0022] For example, if the supplied liquid is a mixture of ethanol and water, the boiling point of ethanol is 78°C and the boiling point of water is 100°C, so the control unit C adjusts the temperature and pressure of the heated steam so that the temperature inside the distillation column 10 becomes 90°C, for example.

[0023] In this embodiment, a heat circulation mechanism is formed that heats the reboiler 13 using a heat pump type steam generating unit 20. Specifically, the condenser circulating water (cooling water) flowing through pipe L3 is at 40 to 70°C, and the condenser waste hot water flowing through pipe L4 is at 50 to 80°C. Furthermore, the heated steam flowing through pipe L1 is at 105 to 150°C, and the reboiler waste hot water flowing through pipe L2 is at 90 to 95°C. This allows the temperature difference between the condenser waste hot water and the heated steam to be greater than 40°C.

[0024] Here, the physical characteristics of heated steam are that it has a large calorific value and is a heat source that can stably supply the optimum temperature. In other words, as long as the pressure is maintained constant, steam is a thermal energy medium that can heat at a constant temperature even if it loses energy, making stable temperature control possible. In addition, heating is achieved by the latent heat released when heated steam condenses and changes phase, so heating is faster than hot water heating. Furthermore, since steam can be introduced due to the phase change, no power is required to introduce the steam.

[0025] In particular, in this embodiment, since it is possible to supply sufficient and stable heat to the distillation column 10, there is no need to lower the boiling point by reducing the pressure using a vacuum suction mechanism, and there is no need to provide a vacuum suction mechanism for this purpose.

[0026] That is, in this embodiment, heat circulation by the heat pump type steam generation unit 20 is performed by steam heating, so that it is possible to achieve high distillation processing efficiency equivalent to that when a boiler is used, thereby achieving energy savings, and since a boiler or the like is not used, it is possible to achieve decarbonization and CO2 reduction.

[0027] The distillation apparatus 1 is not limited to the distillation of alcohols such as ethanol, but can be applied to a wide range of fields, including distillation of hydrocarbons such as toluene and petrochemicals such as benzene.

[0028] Furthermore, the configurations illustrated in the above embodiments and modifications are merely functional schematics and do not necessarily have to be physically configured as shown. In other words, the distribution and integration of each device and component is not limited to that illustrated, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various usage situations, etc. [Explanation of symbols]

[0029] 1. Distillation apparatus 10 Distillation tower 11 Tower bottom 12 Tower top 13 Reboiler 14 Capacitor 15 Receiver 20 Heat pump steam generating unit 30 Heat pump section 31 Evaporator 32 Compressor 33 Condenser 34 Expansion valve 40 Steam generation unit 41 Steam separator 51,52 Storage tank 53 Heat exchanger C control section L1~L4 piping T1, T2 temperature sensors V40 pressure regulating valve

Claims

1. A distillation apparatus in which a feed liquid containing components with different boiling points is fed to a distillation column, the feed liquid at the bottom of the column is heated by a reboiler, low boiling point components are cooled by a condenser and taken out as a distillate from the top of the column, and high boiling point components are taken out as a bottoms from the bottom of the column, A distillation apparatus comprising a heat pump type steam generating unit that generates heated steam by heating reboiler waste water, which is waste hot water of reboiler circulating water that heats the reboiler, using condenser waste hot water, which is waste hot water of condenser circulating water that cools the condenser, as a heat source, and supplies the heated steam to the reboiler.

2. The distillation apparatus according to claim 1, wherein the heat pump type steam generating unit includes a steam separator that heats the reboiler waste hot water by a condenser and separates the heated reboiler waste hot water, which is gas-liquid two-phase water, into saturated steam and hot water, and circulates the hot water from the steam separator to the condenser side.

3. 2. The distillation apparatus according to claim 1, wherein a condenser-side storage tank is provided between the condenser and the heat pump type steam generating unit, and the condenser discharged hot water is stored in the condenser-side storage tank.

4. 2. The distillation apparatus according to claim 1, wherein a reboiler-side storage tank is provided between the reboiler and the heat pump type steam generating unit, and the reboiler waste hot water is stored in the reboiler-side storage tank.

5. The distillation column is provided with a temperature sensor that detects the temperature inside the distillation column, 2. The distillation apparatus according to claim 1, wherein the heat pump type vapor generating unit controls the supply of the heated vapor based on the detected temperature detected by the temperature sensor so that the temperature inside the distillation column is between the low boiling point temperature of the low boiling point component and the high boiling point temperature of the high boiling point component.

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