[go: up one dir, main page]

WO2012067101A1 - Method and device for controlling system for chemically absorbing carbon dioxide - Google Patents

Method and device for controlling system for chemically absorbing carbon dioxide Download PDF

Info

Publication number
WO2012067101A1
WO2012067101A1 PCT/JP2011/076272 JP2011076272W WO2012067101A1 WO 2012067101 A1 WO2012067101 A1 WO 2012067101A1 JP 2011076272 W JP2011076272 W JP 2011076272W WO 2012067101 A1 WO2012067101 A1 WO 2012067101A1
Authority
WO
WIPO (PCT)
Prior art keywords
amine
absorption
regeneration tower
tower
absorber
Prior art date
Application number
PCT/JP2011/076272
Other languages
French (fr)
Japanese (ja)
Inventor
島村　潤
利夫 勝部
Original Assignee
バブコック日立株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by バブコック日立株式会社 filed Critical バブコック日立株式会社
Publication of WO2012067101A1 publication Critical patent/WO2012067101A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1456—Removing acid components
    • B01D53/1475—Removing carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
    • B01D53/1425—Regeneration of liquid absorbents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/62—Carbon oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/20—Organic absorbents
    • B01D2252/204—Amines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/50—Carbon oxides
    • B01D2257/504—Carbon dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/65—Employing advanced heat integration, e.g. Pinch technology
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/40—Capture or disposal of greenhouse gases of CO2

Definitions

  • the present invention relates to a control method and apparatus for a carbon dioxide chemical absorption system, and more particularly to a control method and apparatus for a carbon dioxide chemical absorption system for removing carbon dioxide in exhaust gas generated by combustion of chemical fuel such as a thermal power plant. About.
  • CO 2 carbon dioxide
  • alkanolamine aqueous solution a CO 2 absorbing solution
  • HSS heat stable salt
  • the present invention relates to a method for controlling a CO 2 absorption system provided with an amine absorbent regenerator having a reclaimer by this distillation method.
  • the CO 2 chemical absorption system mainly comprises a boiler 1, a denitration device 2, an air heater 3, an electrostatic precipitator 4, a wet desulfurization device 5, a press clubber 10, a CO 2 absorption tower 20, a regeneration tower 40, a reboiler 60, etc.
  • the combustion exhaust gas discharged from the boiler 1 by the combustion of fossil fuel such as coal is subjected to heat exchange by the air heater 3 after removing nitrogen oxide by the denitration device 2 and cooled to 120 to 170 ° C., for example.
  • the exhaust gas that has passed through the air heater 3 is removed by soot and dust with an electric dust collector 4, and further pressurized with an induction fan, and then sulfur oxide (SO 2 ) is removed with a wet desulfurization device 5.
  • SO 2 sulfur oxide
  • exit gas is customary that the SO 2 is about several tens of ppm residual, to prevent the deterioration of the CO 2 absorbing solution in a CO 2 absorption tower 20 by the residual SO 2, CO 2
  • a press clubber 10 is installed as a pretreatment facility for the chemical absorption facility, and residual SO 2 is reduced as much as possible (for example, 1 ppm or less).
  • the CO 2 absorption tower 20 is mainly composed of a packed bed 21, an absorbing liquid spray part 22, a water washing part 24, a water washing spray part 25, a demister 26, a water washing water reservoir part 27, a cooler 28, and a water washing pump 29.
  • CO 2 contained in the exhaust gas absorbing the filling layer 21, the gas-liquid contact with the CO 2 absorbing liquid supplied from the CO 2 absorption tower 20 top of CO 2 absorbing solution spraying unit 22, the CO 2 absorbing solution Is done.
  • cooling of the de-CO 2 gas 23 whose temperature has risen due to heat generation during the absorption reaction and mist accompanying the gas are removed. Further, the flush water cooled by the cooler 28 is circulated and used by the flush pump 29.
  • a demister 26 is installed in the upper part of the water washing section 24, and after removing the mist accompanying the gas, it is discharged to the outside as a processing gas 37 (de-CO 2 gas).
  • the absorption liquid that has absorbed CO 2 is extracted from the liquid reservoir at the bottom of the absorption tower 20 by the absorption tower extraction pump 33, heated by the heat exchanger 34, and then sent to the regeneration tower 40 that regenerates the amine absorption liquid. Is done.
  • the regeneration tower 40 an absorbing liquid rich in CO 2 sprayed from the spray section 42 is supplied to the packed bed 41.
  • steam is supplied from the reboiler 60 through the steam supply pipe 65 to the bottom of the regeneration tower 40.
  • the packed bed 41 when the absorbing liquid rich in CO 2 comes into gas-liquid contact with the vapor rising from the bottom, CO 2 is degassed from the absorbing liquid into the gas phase.
  • a demister 45 is installed in the upper part of the washing spray part 44, and after removing mist accompanying the gas from the washing part 43 and the like, it is discharged as CO 2 gas 46 from the upper part of the regeneration tower 40. Thereafter, the CO 2 gas is cooled to about 40 ° C. by the cooler 47, separated into gas and condensed water by the CO 2 separator 48, and the CO 2 gas is introduced into a CO 2 liquefaction facility (not shown) and condensed water. Is supplied to the washing spray section 44 by the drain pump 50.
  • the CO 2 absorption liquid from which CO 2 has been degassed is stored in the regeneration tower liquid reservoir 51 and then sent to the reboiler 60 through the reboiler liquid supply pipe 52.
  • a heat transfer tube or the like is installed inside the reboiler 60, and steam is generated inside the reboiler 60 by indirect heating of the CO 2 absorbing liquid with the steam 62 supplied through the steam supply pipe, and the steam is steam. It is supplied to the regeneration tower 40 through the supply pipe 65.
  • the steam 62 used in the reboiler 60 is recovered as drainage in the heat transfer tube.
  • the CO 2 absorbent stored in the liquid reservoir at the bottom of the regeneration tower 40 is cooled by the pump 93 via the heat exchanger 34 and the cooler 31 through the regeneration tower liquid extraction pipe 66, and then absorbed by CO 2. Returned to Tower 20.
  • the sulfur dioxide (SO 2 ) is slightly mixed in the exhaust gas supplied to the absorption tower 20, and most of this SO 2 reacts with the CO 2 absorption liquid, and heat stable salt (HSS). Abbreviated).
  • This HSS is dissolved in the absorbing solution but loses its reactivity with CO 2 and this reaction is irreversible. Therefore, the higher the HSS concentration in the absorbing solution, the more the CO 2 regeneration energy increases because the equilibrium relationship between amine and CO 2 is lost. Therefore, a reclaimer 94 is used to remove this HSS.
  • the reclaimer 94 comprises a reaction vessel provided with a steam supply pipe 56 for heating. After supplying a Na-based alkaline solution such as Na 2 CO 3 into the reaction vessel, an amine absorbing solution is supplied. Then, HSS in the absorbing solution is reacted with the alkaline solution, and sulfur (S) in the HSS bonded to the amine is dissociated to remove HSS as water-soluble Na 2 SO 4 . Thereafter, the liquid in the reaction vessel is heated by the vapor supply pipe 96 to evaporate and collect the amine absorbing liquid.
  • a Na-based alkaline solution such as Na 2 CO 3
  • an amine absorbing solution is supplied.
  • HSS in the absorbing solution is reacted with the alkaline solution
  • sulfur (S) in the HSS bonded to the amine is dissociated to remove HSS as water-soluble Na 2 SO 4 .
  • the liquid in the reaction vessel is heated by the vapor supply pipe 96 to evaporate and collect the amine absorbing liquid.
  • the operation of the reclaimer 94 in the system is performed as follows. First, the operation of the CO 2 absorption facility 20 is stopped. The CO 2 absorbing solution from which CO 2 has been degassed by the regeneration tower 40 is supplied to the reclaimer 94 via the pipe 66 and the flow meter 92 and the shut-off valve 91 via the pump 93. The CO 2 absorbent is monitored by a level transmitter 95 installed in the reclaimer 94 and supplied until the water level is full. When the water level is full, the shutoff valve 91 is closed.
  • the HSS in the amine solution reacts with the alkali solution, that is, the S bound to the amine is dissociated and becomes water-soluble. Na 2 SO 4 .
  • the shutoff valve 98 is opened, and high temperature steam is supplied through the steam supply pipe 96, whereby the CO 2 absorbing liquid is boiled and evaporated.
  • the steam in the steam supply pipe 96 supplied to the reclaimer 94 is separated from Na 2 SO 4 by boiling and evaporating the amine, and is normally used in the reboiler 60 and is set to avoid thermal decomposition of the amine. The one having a temperature higher than the temperature is used.
  • the evaporated CO 2 absorbing solution passes through the amine vapor pipe 97 and is returned to the regeneration tower 40.
  • Vapor of amine absorbent elevated the regeneration tower 40 is cooled by the water-washing section 43, liquefied by being cooled to about 40 ° C.
  • condenser 47 exits the regenerator 40, CO 2 separator 48 Then, after separating CO 2 , it is returned to the regeneration tower 40 via the drain pump 50.
  • Na 2 SO 4 gradually concentrates in the reclaimer 94, but when the amine absorption liquid evaporates and the water level drops to the specified level, the supply of steam to the reclaimer 94 is terminated and the shut-off valve 98 is closed. .
  • the waste amine solution containing Na 2 SO 4 is collected in the waste amine tank 101 by opening the shut-off valve 100 installed in the pipe 99.
  • the reclaimer 94 sufficiently evaporates and recovers the amine absorption liquid, and therefore, the temperature close to the boiling point of the pure amine (for example, 110 to 130 ° C.) compared to the operating temperature of the heating steam in the reboiler 60 (for example, 110 to 130 ° C.). It was necessary to raise the temperature to 130 ° C to 180 ° C and operate the heating steam.
  • the steam supplied from the steam supply pipe 96 also has a higher temperature and a higher pressure than the steam supply pipe 62, but not only that, but in order to set the boiling point of the reclaimer 94 to the operating temperature, after the CO 2 separator 48 It was necessary to increase the pressure of the entire system by installing a pressure regulating valve (not shown) in the flow. For this reason, the system pressure of the regeneration tower 40 must be changed from normal operating conditions, and therefore, when the reclaimer 94 is operated, the operation of the CO 2 absorption facility 20 must be stopped as described above. There was a point. Stopping the operation of the CO 2 absorption facility 20 is undesirable because it reduces the reliability of the facility.
  • An object of the present invention is to avoid the stop of the CO 2 absorption facility, which was a problem in the operation of the reclaimer indispensable in the CO 2 absorption facility of the exhaust gas mixed with S components such as SO 2 , and to regenerate the amine absorption liquid CO equipped with a CO 2 absorbent regenerator that enables effective use of the supplied heat by controlling the steam generated from the CO 2 absorbent regenerator to the optimal temperature and pressure before supply to 40 2.
  • S components such as SO 2
  • the amine absorbing solution in a CO 2 chemical absorption system Before feeding, the amine absorbing solution in a CO 2 chemical absorption system based a source of coolant, the CO 2 chemical absorption system and controls so that the temperature and pressure of the same degree as the heated steam of the reboiler Control method.
  • the amine absorption liquid after the heat exchange which is circulated from the regeneration tower to the CO 2 absorption tower, is branched to serve as a refrigerant source for temperature control of the vapor. Method.
  • the method according to (2) wherein the steam is cooled by directly spraying the amine absorbent after the heat exchange into the absorbent regenerator.
  • the heat-exchanged amine absorbing liquid is heat-exchanged with the steam via a heat exchanger, and the steam is indirectly cooled.
  • the water level is controlled by installing a buffer tank in the amine absorption liquid piping system so that the water level of the absorption tower, the regeneration tower, and the reboiler does not drop. ) Any one of the methods. (6) The method according to any one of (1) to (5), wherein the control is performed while the CO 2 chemical absorption system is operated.
  • a pressure gauge 81 and a pressure regulating valve 82 are installed in the amine vapor pipe 97 from the reclaimer 94, and the reboiler 60 is controlled by controlling the indicated value of the pressure gauge 81 to be the same as the pressure of the reboiler 60.
  • a heat source necessary for CO 2 regeneration can be supplied from the reclaimer 94.
  • the CO 2 absorbent in the system is used as a refrigerant source for the steam generated from the CO 2 absorbent regeneration facility (reclaimer 94), and the temperature of the regeneration tower 40 is controlled by reducing the temperature of the steam to a predetermined temperature. Can be prevented from rising (including locally).
  • the CO 2 absorbing liquid used as a refrigerant source is sprayed on the amine vapor pipe 97 using a spray nozzle or the like and directly brought into contact with the vapor, or the temperature of the vapor is indirectly reduced using a heat exchanger or the like. May be. There is no limitation on the contact method between the CO 2 absorbent and the vapor.
  • the thermal energy used to reduce the temperature of the steam is transferred to the CO 2 absorbing liquid side, and there is no loss of heat energy due to the temperature reduction of the steam in the system in principle.
  • the steam temperature is controlled before the regeneration tower 40 is supplied, and the amount of heat used to efficiently reduce the temperature of the steam is converted into the regeneration tower 40 via the CO 2 absorbent. Can be returned to.
  • regeneration of the CO 2 absorbing liquid can be carried out during operation without stopping the CO 2 absorbing equipment, and effective use of the heat that has been conventionally discarded can be achieved. Reliability and efficiency can be improved.
  • FIG. 1 is a schematic view of a CO 2 chemical absorption system showing an embodiment of the present invention.
  • FIG. 5 An embodiment according to the present invention is shown in FIG.
  • the difference between the present invention and the conventional apparatus shown in FIG. 5 is that a pressure gauge 81 and a pressure regulating valve 82 are installed in the amine absorption liquid vapor pipe 97 to control the vapor pressure of the amine absorption liquid supplied to the regeneration tower 40.
  • the amine absorbent is used as a refrigerant source for the vapor generated from the CO 2 absorbent regenerator composed of the reclaimer 94, etc., and the amine absorbent supplied to the regeneration tower 40 is optimally controlled. It is to be.
  • the amine absorbent extracted from the bottom of the regeneration tower 40 through a pipe 66 is supplied to a reclaimer 94 through a pipe 96, a flow meter 92 and a shut-off valve 91 by a pump 93.
  • the water level in the claimer 94 is monitored by a level transmitter 95, and the shutoff valve 92 is closed when the water level is full.
  • a Na-based alkaline solution such as Na 2 CO 3 is supplied to the reclaimer 94 in advance, and this Na 2 CO 3 reacts with HSS in the amine to dissociate S bonded to the amine, thereby Na 2 SO 3. 4 and HSS is removed.
  • the shutoff valve 98 is opened and high temperature steam is supplied through the steam supply pipe 96, whereby the CO 2 absorbing liquid in the reboiler 96 is boiled and evaporated.
  • the evaporated CO 2 absorbing solution passes through the amine absorbing solution vapor pipe 97 and is charged into the cooler 83.
  • the temperature of the amine absorbing solution at the outlet of the cooler 83 is measured by a thermometer 85, and the flow rate of the amine absorbing solution for cooling is controlled by the flow rate adjusting valve 84 so that the operating temperature of the reboiler 60 is reached.
  • the pressure adjusting valve 82 after being controlled by the pressure adjusting valve 82 so as to have the same pressure as the reboiler 60, the pressure is returned to the regeneration tower 40.
  • Na 2 SO 4 gradually concentrates in the reclaimer 94.
  • the amine absorption liquid evaporates and the water level is lowered to the specified level, the supply of steam to the reclaimer 94 is terminated.
  • the shut-off valve 98 is closed, the shut-off valve 100 installed in the waste amine pipe 99 is opened, and the waste amine liquid containing Na 2 SO 4 is discharged to the waste amine tank.
  • FIGS. Another embodiment according to the present invention is shown in FIGS.
  • the embodiment shown in FIG. 2 is provided with a bypass line between the pump 33 and the heat exchanger 34, the cooler 83 is used as a heat exchanger, and is absorbed as a cooling medium.
  • the difference is that the amine absorbent supplied from the column 20 is used.
  • FIG. 3 differs from the embodiment shown in FIG. 1 in that a buffer tank 86 and a buffer pump 87 are installed between the cooler 31 and the absorption tower 20.
  • a buffer tank 86 and a buffer pump 87 are installed between the cooler 31 and the absorption tower 20.
  • the reclaimer 94 When supplying the amine absorbing liquid to the water, the buffer pump 87 is started and the flow rate adjusting valve 88 is operated to keep the water level constant. Since the water level rises after the operation of the reclaimer 94 is started, the shutoff valve 89 may be opened to keep the water level of the absorption tower 20 and the like constant.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Gas Separation By Absorption (AREA)
  • Treating Waste Gases (AREA)

Abstract

[Problem] To provide a method for controlling a system for absorbing CO2, wherein a CO2 absorber can be recycled and heat can be effectively used during the operation of a CO2 absorption equipment. [Solution] A system comprises: a CO2 absorption equipment in which exhaust gas is brought into contact with absorber to absorb CO2 in the exhaust gas in an absorption tower (20), then the CO2 is desorbed in a regeneration tower (40), the absorber after the CO2 desorption is heated, then the absorber that circulates in the regeneration tower (40) and is extracted from the regeneration tower (40) is heat exchanged with the absorber that is supplied to the regeneration tower, and then the absorber circulates in the absorption tower (20); and an absorber recycling apparatus (94) in which the absorber is extracted from the regeneration tower (40), thermally-stable salts that are accumulated in an amine absorber are removed by a distillation method, and then the generated vapor of the absorber is supplied to the regeneration tower. The vapor generated from the absorber recycling apparatus is controlled to have similar temperature and pressure to those of heating steam of a reboiler using the absorber in the system for chemically absorbing carbon dioxide as a refrigerant source before being supplied to the regeneration tower (40).

Description

二酸化炭素化学吸収システムの制御方法および装置Method and apparatus for controlling carbon dioxide chemical absorption system
　本発明は、二酸化炭素化学吸収システムの制御方法および装置に係り、特に火力発電所などの化学燃料の燃焼により発生する排ガス中の二酸化炭素を除去するための二酸化炭素化学吸収システムの制御方法および装置に関する。 The present invention relates to a control method and apparatus for a carbon dioxide chemical absorption system, and more particularly to a control method and apparatus for a carbon dioxide chemical absorption system for removing carbon dioxide in exhaust gas generated by combustion of chemical fuel such as a thermal power plant. About.
　火力発電所では、化石燃料の燃焼により電気エネルギーを得る代償として、多大な二酸化炭素(以下、CO2と記す)が排ガスの一部として大気中に排出されている。CO2は、フロンやメタンと共に地球温暖化を促進させる保温ガスであり、現在、その排出抑制技術が実用化されつつあるが、その一つとしてアルカノールアミン水溶液のようなCO2吸収液（以下、アミン吸収液という）を用いてCO2を吸収除去するCO2化学吸収システムが注目されている。このCO2化学吸収システムの難点の一つとして大量の熱量を必要とすることが挙げられる。すなわち、このシステムにおいて、CO2吸収液中のアミン類が運転中に排ガス中に含まれるS分と反応し、熱安定性塩（Heat Stable Salt; HSSと称する）を形成する。一度、HSSとなったアミン吸収液は元に戻らず、吸収液中に堆積していく。吸収液中のHSS濃度が上がっていくと、アミンとCO2の平衡関係が崩れるため、CO2吸収および吸収液の加熱再生により多くのエネルギーが必要となる。従来、アミン吸収液中に蓄積したHSSの除去のため、リクレーマと呼ばれる除去装置が使用されている。リクレーマにはいくつかタイプがあるが、ばいじんを含む石炭焚ボイラ排ガスを処理する場合には、HSSを含むアミン吸収液をNa2CO3などのアルカリ塩と共に加熱蒸発させ、HSSを分解除去すると共に、アミン吸収液を再生する、いわゆる蒸留法が有効であると考えれられている。本発明は、この蒸留法によるリクレーマを有するアミン吸収液再生装置を備えたCO2吸収システムの制御方法に関する。 In a thermal power plant, a large amount of carbon dioxide (hereinafter referred to as CO 2 ) is discharged into the atmosphere as a part of exhaust gas as a price for obtaining electric energy by burning fossil fuel. CO 2 is a thermal insulation gas that promotes global warming together with chlorofluorocarbon and methane, and its emission control technology is currently being put into practical use. One of these is a CO 2 absorbing solution (hereinafter referred to as “alkanolamine aqueous solution”). A CO 2 chemical absorption system that absorbs and removes CO 2 by using an amine absorbing solution) has attracted attention. One of the difficulties of this CO 2 chemical absorption system is that it requires a large amount of heat. That is, in this system, the amines in the CO 2 absorbing solution react with the S component contained in the exhaust gas during operation to form a heat stable salt (referred to as HSS). Once the amine absorption liquid that has become HSS does not return to its original state, it accumulates in the absorption liquid. As the HSS concentration in the absorption liquid increases, the equilibrium relationship between amine and CO 2 is lost, so that more energy is required for CO 2 absorption and heat regeneration of the absorption liquid. Conventionally, a removal device called a reclaimer has been used to remove HSS accumulated in an amine absorbing solution. There are several types of reclaimers, but when treating coal-fired boiler exhaust gas containing soot and dust, HSS is decomposed and removed by heating and evaporating amine absorption liquid containing HSS together with alkali salts such as Na 2 CO 3. It is considered that a so-called distillation method for regenerating the amine absorbing solution is effective. The present invention relates to a method for controlling a CO 2 absorption system provided with an amine absorbent regenerator having a reclaimer by this distillation method.
　従来の発電プラントのCO2化学吸収システム一例を図５に示す。該CO2化学吸収システムは、主にボイラ1、脱硝装置2、エアヒータ3、電気集塵装置4、湿式脱硫装置5、プレスクラバー10、CO2吸収塔20、再生塔40、リボイラ60等から構成されている。石炭等の化石燃料の燃焼によりボイラ１から排出される燃焼排ガスは、脱硝装置２で窒素酸化物を除去した後、エアヒータ３で熱交換され、例えば120～170℃に冷却される。エアヒータ３を通過した排ガスは電気集塵機４でばいじん除去され、さらに誘引ファンで昇圧した後、湿式脱硫装置５で硫黄酸化物(SO2)が除去される。湿式脱硫装置５出口ガス中には数十ppm程度のSO2が残存するのが通例であり、該残存SO2によるCO2吸収塔20内のCO2吸収液の劣化を防止するため、CO2化学吸収設備の前処理設備としてプレスクラバー10が設置され、残存SO2が極力低減(例えば1ppm以下)される。 An example of a conventional CO 2 chemical absorption system for a power plant is shown in FIG. The CO 2 chemical absorption system mainly comprises a boiler 1, a denitration device 2, an air heater 3, an electrostatic precipitator 4, a wet desulfurization device 5, a press clubber 10, a CO 2 absorption tower 20, a regeneration tower 40, a reboiler 60, etc. Has been. The combustion exhaust gas discharged from the boiler 1 by the combustion of fossil fuel such as coal is subjected to heat exchange by the air heater 3 after removing nitrogen oxide by the denitration device 2 and cooled to 120 to 170 ° C., for example. The exhaust gas that has passed through the air heater 3 is removed by soot and dust with an electric dust collector 4, and further pressurized with an induction fan, and then sulfur oxide (SO 2 ) is removed with a wet desulfurization device 5. During wet desulfurization system 5 exit gas is customary that the SO 2 is about several tens of ppm residual, to prevent the deterioration of the CO 2 absorbing solution in a CO 2 absorption tower 20 by the residual SO 2, CO 2 A press clubber 10 is installed as a pretreatment facility for the chemical absorption facility, and residual SO 2 is reduced as much as possible (for example, 1 ppm or less).
　CO2吸収塔20は、主に充填層21、吸収液スプレ部22、水洗部24、水洗スプレ部25、デミスタ26、水洗水溜め部27、冷却器28、および水洗ポンプ29で構成される。排ガス中に含まれるCO2は、充填層21において、CO2吸収塔20上部のCO2吸収液スプレ部22から供給されるCO2吸収液との気液接触により、CO2吸収液中へ吸収される。水洗部24では、吸収反応時の発熱により温度が上昇した脱CO2ガス23の冷却およびガスに同伴するミストが除去される。また、冷却器28によって冷却された水洗水は、水洗ポンプ29によって循環使用される。水洗部24上部にはデミスタ26が設置され、ガス中に同伴されたミストを除去した後、処理ガス37(脱CO2ガス)として外部に排出される。 The CO 2 absorption tower 20 is mainly composed of a packed bed 21, an absorbing liquid spray part 22, a water washing part 24, a water washing spray part 25, a demister 26, a water washing water reservoir part 27, a cooler 28, and a water washing pump 29. CO 2 contained in the exhaust gas, absorbing the filling layer 21, the gas-liquid contact with the CO 2 absorbing liquid supplied from the CO 2 absorption tower 20 top of CO 2 absorbing solution spraying unit 22, the CO 2 absorbing solution Is done. In the water washing section 24, cooling of the de-CO 2 gas 23 whose temperature has risen due to heat generation during the absorption reaction and mist accompanying the gas are removed. Further, the flush water cooled by the cooler 28 is circulated and used by the flush pump 29. A demister 26 is installed in the upper part of the water washing section 24, and after removing the mist accompanying the gas, it is discharged to the outside as a processing gas 37 (de-CO 2 gas).
　次にCO2を吸収した吸収液は、吸収塔20下部の液溜めから吸収塔抜出しポンプ33により抜き出され、熱交換器34によって昇温後、アミン吸収液を再生する再生塔40に送液される。再生塔40内では、スプレ部42から噴霧される、CO2をリッチに含む吸収液が充填層41に供給される。一方、再生塔40底部には、リボイラ60から蒸気供給配管65を介して蒸気が供給される。充填層41において、 CO2をリッチに含む吸収液が底部より上昇してくる蒸気と気液接触することにより、吸収液中からCO2が気相中へ脱気される。脱気したCO2ガス中には、一部吸収液ミストが同伴されるが、水洗部43で該ミストが除去される。水洗スプレ部44上部にはデミスタ45が設置され、水洗部43等からガス中に同伴されたミストを除去した後、CO2ガス46として再生塔40上部から排出される。その後、CO2ガスは冷却器47によって約40℃に冷却され、CO2分離器48でガスと凝縮水に分離され、CO2ガスはCO2液化設備（図示省略）へ導入され、凝縮した水はドレンポンプ50によって水洗スプレ部44に供給される。 Next, the absorption liquid that has absorbed CO 2 is extracted from the liquid reservoir at the bottom of the absorption tower 20 by the absorption tower extraction pump 33, heated by the heat exchanger 34, and then sent to the regeneration tower 40 that regenerates the amine absorption liquid. Is done. In the regeneration tower 40, an absorbing liquid rich in CO 2 sprayed from the spray section 42 is supplied to the packed bed 41. On the other hand, steam is supplied from the reboiler 60 through the steam supply pipe 65 to the bottom of the regeneration tower 40. In the packed bed 41, when the absorbing liquid rich in CO 2 comes into gas-liquid contact with the vapor rising from the bottom, CO 2 is degassed from the absorbing liquid into the gas phase. In the degassed CO 2 gas, a part of the absorbing liquid mist is accompanied, but the mist is removed by the water washing section 43. A demister 45 is installed in the upper part of the washing spray part 44, and after removing mist accompanying the gas from the washing part 43 and the like, it is discharged as CO 2 gas 46 from the upper part of the regeneration tower 40. Thereafter, the CO 2 gas is cooled to about 40 ° C. by the cooler 47, separated into gas and condensed water by the CO 2 separator 48, and the CO 2 gas is introduced into a CO 2 liquefaction facility (not shown) and condensed water. Is supplied to the washing spray section 44 by the drain pump 50.
　一方、CO2を脱気したCO2吸収液は、再生塔液溜め部51に溜められた後、リボイラ液供給配管52を通ってリボイラ60に送液される。リボイラ60内部には伝熱管等が設置されており、CO2吸収液が蒸気供給配管を介して供給される蒸気62で間接加熱されることによりリボイラ60内部では蒸気が発生し、該蒸気が蒸気供給配管65を通って、再生塔40に供給される。リボイラ60にて使用した蒸気62は伝熱管中でドレンとなり回収される。再生塔40底部の液溜め部に溜められたCO2吸収液は、再生塔液抜出し配管66を介して、ポンプ93により熱交換器34および冷却器31を経て減温された後、CO2吸収塔20に戻される。 On the other hand, the CO 2 absorption liquid from which CO 2 has been degassed is stored in the regeneration tower liquid reservoir 51 and then sent to the reboiler 60 through the reboiler liquid supply pipe 52. A heat transfer tube or the like is installed inside the reboiler 60, and steam is generated inside the reboiler 60 by indirect heating of the CO 2 absorbing liquid with the steam 62 supplied through the steam supply pipe, and the steam is steam. It is supplied to the regeneration tower 40 through the supply pipe 65. The steam 62 used in the reboiler 60 is recovered as drainage in the heat transfer tube. The CO 2 absorbent stored in the liquid reservoir at the bottom of the regeneration tower 40 is cooled by the pump 93 via the heat exchanger 34 and the cooler 31 through the regeneration tower liquid extraction pipe 66, and then absorbed by CO 2. Returned to Tower 20.
　ところで、吸収塔20に供給される排ガスには二酸化硫黄（SO2）が僅かに混入しており、このSO2のほとんどはCO2吸収液と反応し、熱安定性塩（Heat Stable Salt; HSSと略す）を形成する。このHSSは吸収液に溶存するが、CO2との反応性が失われ、かつこの反応は不可逆的である。したがって、吸収液中のHSS濃度が上昇すればするほど、アミンとCO2の平衡関係が崩れるため、CO2再生エネルギーが増加していく。そこで、このHSSを除去するため、リクレーマ94が使用される。 By the way, the sulfur dioxide (SO 2 ) is slightly mixed in the exhaust gas supplied to the absorption tower 20, and most of this SO 2 reacts with the CO 2 absorption liquid, and heat stable salt (HSS). Abbreviated). This HSS is dissolved in the absorbing solution but loses its reactivity with CO 2 and this reaction is irreversible. Therefore, the higher the HSS concentration in the absorbing solution, the more the CO 2 regeneration energy increases because the equilibrium relationship between amine and CO 2 is lost. Therefore, a reclaimer 94 is used to remove this HSS.
　リクレーマ94は、反応容器内に加熱用の蒸気供給配管56を設けたものからなり、この反応容器内にNa2CO3などのNa系アルカリ溶液を供給した後、アミン吸収液を供給することにより、吸収液中のHSSを前記アルカリ溶液と反応させ、アミンと結合したHSS中の硫黄（S）が解離し、水溶性のNa2SO4としてHSSを除去するものである。その後、蒸気供給配管96で反応容器内の液を加熱し、アミン吸収液を蒸発、回収する。 The reclaimer 94 comprises a reaction vessel provided with a steam supply pipe 56 for heating. After supplying a Na-based alkaline solution such as Na 2 CO 3 into the reaction vessel, an amine absorbing solution is supplied. Then, HSS in the absorbing solution is reacted with the alkaline solution, and sulfur (S) in the HSS bonded to the amine is dissociated to remove HSS as water-soluble Na 2 SO 4 . Thereafter, the liquid in the reaction vessel is heated by the vapor supply pipe 96 to evaporate and collect the amine absorbing liquid.
　システム内でのリクレーマ94の操作は以下のように実施する。まず、CO2吸収設備20の運用を止める。再生塔40でCO2を脱気したCO2吸収液は、配管66を介してポンプ93により流量計92および遮断弁91を介してリクレーマ94に投入される。CO2吸収液は、リクレーマ94に設置されているレベル発信機95で水位を監視し、満水になるまで供給し、満水になると遮断弁91を閉じる。リクレーマ94には、予めNa2CO3などのNa系のアルカリ溶液を供給しておくことにより、アミン液中のHSSがアルカリ溶液と反応、すなわちアミンと結合していたSが解離し、水溶性のNa2SO4となる。次に遮断弁98を開放、蒸気供給配管96を介し高温蒸気を供給することにより、CO2吸収液を沸騰、蒸発させる。リクレーマ94に供給する蒸気供給配管96の蒸気は、アミンを沸騰、蒸発させることによりNa2SO4と分離させるため、通常、リボイラ60で使用される、アミンの熱分解を避けるために設定した蒸気温度より高温のものが使用される。蒸発したCO2吸収液は、アミン蒸気配管97を通り、再生塔40へ戻される。再生塔40を上昇したアミン吸収液の蒸気は、水洗部43で冷却された後、再生塔40を出てさらに冷却器47で40℃程度に冷却されることで液化し、CO2分離器48でCO2を分離した後、ドレンポンプ50を介して再生塔40へ戻される。一方、リクレーマ94内では次第にNa2SO4が濃縮していくが、アミン吸収液等が蒸発し、指定レベルまで水位が低下した時点でリクレーマ94への蒸気供給を終了し、遮断弁98を閉める。Na2SO4を含む廃アミン液は、配管99に設置された遮断弁100を開け、廃アミンタンク101へ回収される。 The operation of the reclaimer 94 in the system is performed as follows. First, the operation of the CO 2 absorption facility 20 is stopped. The CO 2 absorbing solution from which CO 2 has been degassed by the regeneration tower 40 is supplied to the reclaimer 94 via the pipe 66 and the flow meter 92 and the shut-off valve 91 via the pump 93. The CO 2 absorbent is monitored by a level transmitter 95 installed in the reclaimer 94 and supplied until the water level is full. When the water level is full, the shutoff valve 91 is closed. By supplying a Na-based alkali solution such as Na 2 CO 3 in advance to the reclaimer 94, the HSS in the amine solution reacts with the alkali solution, that is, the S bound to the amine is dissociated and becomes water-soluble. Na 2 SO 4 . Next, the shutoff valve 98 is opened, and high temperature steam is supplied through the steam supply pipe 96, whereby the CO 2 absorbing liquid is boiled and evaporated. The steam in the steam supply pipe 96 supplied to the reclaimer 94 is separated from Na 2 SO 4 by boiling and evaporating the amine, and is normally used in the reboiler 60 and is set to avoid thermal decomposition of the amine. The one having a temperature higher than the temperature is used. The evaporated CO 2 absorbing solution passes through the amine vapor pipe 97 and is returned to the regeneration tower 40. Vapor of amine absorbent elevated the regeneration tower 40 is cooled by the water-washing section 43, liquefied by being cooled to about 40 ° C. In addition condenser 47 exits the regenerator 40, CO 2 separator 48 Then, after separating CO 2 , it is returned to the regeneration tower 40 via the drain pump 50. On the other hand, Na 2 SO 4 gradually concentrates in the reclaimer 94, but when the amine absorption liquid evaporates and the water level drops to the specified level, the supply of steam to the reclaimer 94 is terminated and the shut-off valve 98 is closed. . The waste amine solution containing Na 2 SO 4 is collected in the waste amine tank 101 by opening the shut-off valve 100 installed in the pipe 99.
　上述の従来技術において、リクレーマ94ではアミン吸収液を十分蒸発させ、回収するため、リボイラ60での加熱用蒸気の運用温度（たとえば110～130℃）に比べ、純アミンの沸点に近い温度（たとえば130℃～180℃）にまで昇温して加熱用蒸気を運用する必要があった。このため蒸気供給配管96から供給される蒸気も蒸気供給配管62に比べ高温、高圧とすることになるが、それだけではなく、リクレーマ94の沸点を運用温度に設定するため、CO2分離器48後流に圧力調整弁（図示省略）を設置して系全体の圧力を上げる必要があった。そのため、再生塔40の系内圧力は通常の運用条件から変えざるを得ないため、リクレーマ94の運転の際には、前述のようにCO2吸収設備20の運転を止めざるを得ないという問題点があった。CO2吸収設備20の運用を停止するということは、設備の信頼性が低下することになり、望ましくない。 In the above-described prior art, the reclaimer 94 sufficiently evaporates and recovers the amine absorption liquid, and therefore, the temperature close to the boiling point of the pure amine (for example, 110 to 130 ° C.) compared to the operating temperature of the heating steam in the reboiler 60 (for example, 110 to 130 ° C.). It was necessary to raise the temperature to 130 ° C to 180 ° C and operate the heating steam. For this reason, the steam supplied from the steam supply pipe 96 also has a higher temperature and a higher pressure than the steam supply pipe 62, but not only that, but in order to set the boiling point of the reclaimer 94 to the operating temperature, after the CO 2 separator 48 It was necessary to increase the pressure of the entire system by installing a pressure regulating valve (not shown) in the flow. For this reason, the system pressure of the regeneration tower 40 must be changed from normal operating conditions, and therefore, when the reclaimer 94 is operated, the operation of the CO 2 absorption facility 20 must be stopped as described above. There was a point. Stopping the operation of the CO 2 absorption facility 20 is undesirable because it reduces the reliability of the facility.
　また、アミン吸収液の再生に使われる熱のほとんどは冷却器47において冷却（廃棄）せざるを得ず、プラント全体でのエネルギー有効利用の観点からしても、望ましいものではなかった。 In addition, most of the heat used for regenerating the amine absorbing solution must be cooled (discarded) in the cooler 47, which is not desirable from the viewpoint of effective energy use in the entire plant.
　さらに、CO2吸収塔20の運転を止めた場合、CO2回収をしていないガスは、後流機器であるCO2液化設備へ流すことはできないので、CO2分離器48の後流で煙突へつなぎ、大気開放することになるが、CO2調整用に設定してある吸収液中のアミン濃度が変わる要因となり、これも望ましくない。 Furthermore, when the operation of the CO 2 absorption tower 20 is stopped, gas that has not been CO 2 recovered cannot flow to the CO 2 liquefaction facility, which is a downstream device, so the chimney in the downstream of the CO 2 separator 48 Although it is connected to the atmosphere, the amine concentration in the absorbing solution set for CO 2 adjustment is changed, which is also undesirable.
　本発明の課題は、SO2のようなS分が混入する排ガスのCO2吸収設備において不可欠なリクレーマの運転で問題であったCO2吸収設備の停止を回避すると共に、アミン吸収液の再生塔40への供給前に、CO2吸収液再生設備から発生する蒸気を最適な温度、圧力に制御することにより、供給熱の有効利用を図ることができる、CO2吸収液再生設備を備えたCO2化学吸収システムの制御方法を提供することにある。 An object of the present invention is to avoid the stop of the CO 2 absorption facility, which was a problem in the operation of the reclaimer indispensable in the CO 2 absorption facility of the exhaust gas mixed with S components such as SO 2 , and to regenerate the amine absorption liquid CO equipped with a CO 2 absorbent regenerator that enables effective use of the supplied heat by controlling the steam generated from the CO 2 absorbent regenerator to the optimal temperature and pressure before supply to 40 2. To provide a method for controlling a chemical absorption system.
　上記従来技術では、リクレーマ94等から構成されるCO2吸収液再生設備から発生する蒸気の再生塔40への供給において、該蒸気を熱源として有効利用するための蒸気温度管理および制御方法が確立されていなかった。上記の課題は、アミン吸収液蒸気配管97に圧力計81、圧力調整弁82を設置し、圧力計81の指示値がリボイラ圧力と同じになるように制御すること、および系内CO2吸収液の一部を、リクレーマ94等から構成されるCO2吸収液再生設備から発生する蒸気の冷媒源として使用し、アミン吸収液を再生塔40に供給する前にその温度を制御することによって達成される。すなわち、本願で特許請求される発明は下記のとおりである。 In the above prior art, a steam temperature management and control method for effectively using the steam as a heat source in the supply of the steam generated from the CO 2 absorbing liquid regeneration facility including the reclaimer 94 to the regeneration tower 40 has been established. It wasn't. The above problems are that a pressure gauge 81 and a pressure regulating valve 82 are installed in the amine absorbent liquid vapor pipe 97, and the indicated value of the pressure gauge 81 is controlled to be the same as the reboiler pressure, and the in-system CO 2 absorbent Is used as a refrigerant source for the vapor generated from the CO 2 absorption liquid regeneration facility composed of reclaimer 94, etc., and the temperature is controlled before the amine absorption liquid is supplied to the regeneration tower 40. The That is, the invention claimed in the present application is as follows.
（１）化石燃料の燃焼装置から排出される排ガス中の硫黄酸化物を排煙脱硫装置で除去した後、二酸化炭素（CO2）吸収塔内でアミン吸収液と接触させて排ガス中のCO2を吸収し、次いで該CO2を吸収した吸収液を加熱して再生塔内でCO2を離脱させ、CO2離脱後の吸収液をリボイラを介して昇温した後、再生塔に循環すると共に、再生塔から抜き出したアミン吸収液を該再生塔に供給するアミン吸収液と熱交換した後、前記吸収塔に循環するCO2化学吸収設備と、該再生塔からアミン吸収液を抜き出し、該アミン吸収液中に蓄積した熱安定性塩を蒸留法によって除去した後、発生したアミン吸収液の蒸気を前記再生塔に供給する吸収液再生装置とを有するCO2化学吸収システムにおいて、該アミン吸収液再生装置から発生する蒸気が、前記再生塔に供給する前に、CO2化学吸収システム系内のアミン吸収液を冷媒源とし、前記リボイラの加熱蒸気と同程度の温度および圧力になるように制御することを特徴とするCO2化学吸収システムの制御方法。
（２）前記再生塔からCO2吸収塔に循環される、前記熱交換した後のアミン吸収液を分岐し、前記蒸気の温度制御用の冷媒源とすることを特徴とする（１）記載の方法。
（３）前記熱交換した後のアミン吸収液を前記吸収液再生装置内に直接噴霧して前記蒸気を冷却することを特徴とする（２）記載の方法。
（４）前記熱交換した後のアミン吸収液を、熱交換器を介して前記蒸気と熱交換させ、該蒸気を間接的に冷却することを特徴とする（２）記載の方法。
（５）前記吸収塔、再生塔、およびリボイラの水位が下がらないように、アミン吸収液の配管系内にバッファタンクを設置し、前記水位を制御することを特徴とする（１）ないし（４）のいずれかに記載の方法。
（６）前記CO2化学吸収システムを運用したままの状態で、前記制御を行なうことを特徴とする（１）ないし（５）のいずれかに記載の方法。 (1) After removing sulfur oxides in the exhaust gas discharged from the fossil fuel combustion device with the flue gas desulfurization device, it is brought into contact with the amine absorbing solution in the carbon dioxide (CO 2 ) absorption tower and the CO 2 in the exhaust gas. It absorbs, then to disengage the CO 2 absorbing liquid that has absorbed the CO 2 in the heated regenerator, after the absorption solution after CO 2 leaving to warm through the reboiler, the circulating regeneration tower The amine absorption liquid extracted from the regeneration tower is heat-exchanged with the amine absorption liquid supplied to the regeneration tower, and then the CO 2 chemical absorption equipment circulated to the absorption tower, the amine absorption liquid is extracted from the regeneration tower, and the amine In a CO 2 chemical absorption system having an absorption liquid regenerator for supplying vapor of the generated amine absorption liquid to the regeneration tower after removing the heat-stable salt accumulated in the absorption liquid by a distillation method, the amine absorption liquid Steam generated from the regenerator is sent to the regeneration tower. Before feeding, the amine absorbing solution in a CO 2 chemical absorption system based a source of coolant, the CO 2 chemical absorption system and controls so that the temperature and pressure of the same degree as the heated steam of the reboiler Control method.
(2) The amine absorption liquid after the heat exchange, which is circulated from the regeneration tower to the CO 2 absorption tower, is branched to serve as a refrigerant source for temperature control of the vapor. Method.
(3) The method according to (2), wherein the steam is cooled by directly spraying the amine absorbent after the heat exchange into the absorbent regenerator.
(4) The method according to (2), wherein the heat-exchanged amine absorbing liquid is heat-exchanged with the steam via a heat exchanger, and the steam is indirectly cooled.
(5) The water level is controlled by installing a buffer tank in the amine absorption liquid piping system so that the water level of the absorption tower, the regeneration tower, and the reboiler does not drop. ) Any one of the methods.
(6) The method according to any one of (1) to (5), wherein the control is performed while the CO 2 chemical absorption system is operated.
　本発明では、リクレーマ94からのアミン蒸気配管97に圧力計81、圧力調整弁82を設置し、圧力計81の指示値がリボイラ60の圧力と同じになるように制御することにより、リボイラ60とリクレーマ94からCO2再生に必要な熱源を供給することができる。 In the present invention, a pressure gauge 81 and a pressure regulating valve 82 are installed in the amine vapor pipe 97 from the reclaimer 94, and the reboiler 60 is controlled by controlling the indicated value of the pressure gauge 81 to be the same as the pressure of the reboiler 60. A heat source necessary for CO 2 regeneration can be supplied from the reclaimer 94.
　同時に、系内のCO2吸収液をCO2吸収液再生設備（リクレーマ94）から発生する蒸気の冷媒源として使用し、該蒸気を所定の温度まで減温制御することで、再生塔40内温度が(局部的を含め)上昇することを防止することが可能となる。冷媒源として使用するCO2吸収液は、該アミン蒸気配管97にスプレノズル等を用いて噴霧し直接的に該蒸気と接触させるか、熱交換器等を用いて間接的に該蒸気の減温をしてもよい。CO2吸収液と該蒸気との接触方法についてはその制限は無い。 At the same time, the CO 2 absorbent in the system is used as a refrigerant source for the steam generated from the CO 2 absorbent regeneration facility (reclaimer 94), and the temperature of the regeneration tower 40 is controlled by reducing the temperature of the steam to a predetermined temperature. Can be prevented from rising (including locally). The CO 2 absorbing liquid used as a refrigerant source is sprayed on the amine vapor pipe 97 using a spray nozzle or the like and directly brought into contact with the vapor, or the temperature of the vapor is indirectly reduced using a heat exchanger or the like. May be. There is no limitation on the contact method between the CO 2 absorbent and the vapor.
　また、該蒸気の減温に利用された熱エネルギーは、CO2吸収液側に移行されることになり、該蒸気の減温による熱エネルギーの損失は、該系内において原則存在しないことになる。つまり、本発明を採用することにより、該蒸気の温度制御を再生塔40供給前に実施すると共に、効率的に該蒸気の減温に用いた熱量をCO2吸収液を介して再生塔40内に返送できることとなる。 In addition, the thermal energy used to reduce the temperature of the steam is transferred to the CO 2 absorbing liquid side, and there is no loss of heat energy due to the temperature reduction of the steam in the system in principle. . In other words, by adopting the present invention, the steam temperature is controlled before the regeneration tower 40 is supplied, and the amount of heat used to efficiently reduce the temperature of the steam is converted into the regeneration tower 40 via the CO 2 absorbent. Can be returned to.
　本発明によれば、CO2吸収液の再生がCO2吸収設備を停止させることなく、その運用中に実施が可能で、かつ、従来廃棄していた熱の有効利用が図ることができ、プラントの信頼性および効率の向上を図ることができる。 According to the present invention, regeneration of the CO 2 absorbing liquid can be carried out during operation without stopping the CO 2 absorbing equipment, and effective use of the heat that has been conventionally discarded can be achieved. Reliability and efficiency can be improved.
本発明の実施例を示したCO2化学吸収システムの概略図。1 is a schematic view of a CO 2 chemical absorption system showing an embodiment of the present invention. 本発明の他の実施例を示したCO2化学吸収システムの概略図。Schematic diagram of CO 2 chemical absorption system showing another embodiment of the present invention. 本発明のさらに他の実施例を示したCO2化学吸収システムの概略図。Furthermore schematic of CO 2 chemical absorption system showing another embodiment of the present invention. 本発明のアミン吸収液の配管系にさらにバッファタンクを設けた実施例を示す概略図。Schematic which shows the Example which provided the buffer tank further in the piping system of the amine absorption liquid of this invention. 従来技術におけるCO2吸収液再生設備を搭載したCO2化学吸収システムの概略図。Schematic diagram of a CO 2 chemical absorption system equipped with a CO 2 absorbent regeneration facility in the prior art.
　本発明による実施例を図１に示す。本発明と、図５に示した従来装置と異なる点は、アミン吸収液蒸気配管97に圧力計81および圧力調整弁82を設置し、再生塔40に供給されるアミン吸収液の蒸気圧力を制御していること、およびアミン吸収液をリクレーマ94等から構成されるCO2吸収液再生装置から発生する蒸気の冷媒源として使用し、再生塔40に供給されるアミン吸収液を最適な温度制御をすることである。 An embodiment according to the present invention is shown in FIG. The difference between the present invention and the conventional apparatus shown in FIG. 5 is that a pressure gauge 81 and a pressure regulating valve 82 are installed in the amine absorption liquid vapor pipe 97 to control the vapor pressure of the amine absorption liquid supplied to the regeneration tower 40. And the amine absorbent is used as a refrigerant source for the vapor generated from the CO 2 absorbent regenerator composed of the reclaimer 94, etc., and the amine absorbent supplied to the regeneration tower 40 is optimally controlled. It is to be.
　
図１において、再生塔40の塔底から配管66を介して抜き出されたアミン吸収液は、ポンプ93により配管96、流量計92および遮断弁91を通り、リクレーマ94へ供給される。クレーマ94における水位は、レベル発信機95で監視され、満水になった時点で遮断弁92が閉じられる。リクレーマ94には予めNa2CO3などのNa系のアルカリ溶液が供給されており、このNa2CO3がアミン中のHSSと反応し、アミンと結合していたSが解離し、Na2SO4となり、HSSが除去される。次に遮断弁98を開放して蒸気供給配管96を介して高温蒸気を供給することにより、リボイラ96内のCO2吸収液を沸騰、蒸発させる。蒸発したCO2吸収液はアミン吸収液蒸気配管97を通り、冷却器83へ投入される。冷却器83出口のアミン吸収液の温度は温度計85により測定され、リボイラ60の運用温度になるように冷却用のアミン吸収液の流量が流量調整弁84によって制御される。さらにリボイラ60と同一圧力になるよう圧力調整弁82で制御された後、再生塔40へ戻される。一方、リクレーマ94内では次第にNa2SO4が濃縮していく。アミン吸収液が蒸発し、指定レベルまで水位が低下したところで、リクレーマ94への蒸気供給を終了する。遮断弁98を閉め、廃アミン配管99に設置された遮断弁100を開け、Na2SO4を含んだ廃アミン液が廃アミンタンクへ排出される。
In FIG. 1, the amine absorbent extracted from the bottom of the regeneration tower 40 through a pipe 66 is supplied to a reclaimer 94 through a pipe 96, a flow meter 92 and a shut-off valve 91 by a pump 93. The water level in the claimer 94 is monitored by a level transmitter 95, and the shutoff valve 92 is closed when the water level is full. A Na-based alkaline solution such as Na 2 CO 3 is supplied to the reclaimer 94 in advance, and this Na 2 CO 3 reacts with HSS in the amine to dissociate S bonded to the amine, thereby Na 2 SO 3. 4 and HSS is removed. Next, the shutoff valve 98 is opened and high temperature steam is supplied through the steam supply pipe 96, whereby the CO 2 absorbing liquid in the reboiler 96 is boiled and evaporated. The evaporated CO 2 absorbing solution passes through the amine absorbing solution vapor pipe 97 and is charged into the cooler 83. The temperature of the amine absorbing solution at the outlet of the cooler 83 is measured by a thermometer 85, and the flow rate of the amine absorbing solution for cooling is controlled by the flow rate adjusting valve 84 so that the operating temperature of the reboiler 60 is reached. Further, after being controlled by the pressure adjusting valve 82 so as to have the same pressure as the reboiler 60, the pressure is returned to the regeneration tower 40. On the other hand, Na 2 SO 4 gradually concentrates in the reclaimer 94. When the amine absorption liquid evaporates and the water level is lowered to the specified level, the supply of steam to the reclaimer 94 is terminated. The shut-off valve 98 is closed, the shut-off valve 100 installed in the waste amine pipe 99 is opened, and the waste amine liquid containing Na 2 SO 4 is discharged to the waste amine tank.
　本発明による他の実施例を図２および図３に示す。図２に示した実施例は、図１に示した実施例と比較して、ポンプ33と熱交換器34の間にバイパスラインを設け、冷却器83を熱交換器とし、その冷却媒体として吸収塔20から供給されるアミン吸収液を使用した点が異なる。 Another embodiment according to the present invention is shown in FIGS. Compared with the embodiment shown in FIG. 1, the embodiment shown in FIG. 2 is provided with a bypass line between the pump 33 and the heat exchanger 34, the cooler 83 is used as a heat exchanger, and is absorbed as a cooling medium. The difference is that the amine absorbent supplied from the column 20 is used.
　図３の実施例は、図１に示した実施例に加えて、冷却器31と吸収塔20の間にバッファタンク86およびバッファポンプ87等を設置した点が異なる。リクレーマ94へアミン吸収液を供給した時点で、吸収塔20、再生塔40およびリボイラ60の水位がリクレーマ94へ供給した分だけ減少する。運用上問題なければ水位の下がった状態でCO2回収設備の運用を続ければよいが、リクレーマ94の容量が大きく、本水位の減少がCO2回収設備運用に影響を与える場合には、リクレーマ94へアミン吸収液を供給する際に、バッファポンプ87を起動し、流量調整弁88を作動させて前記水位を一定に保つ。リクレーマ94の運用が開始されてからは水位が上昇するので、遮断弁89を開放し、吸収塔20等の水位を一定に保てばよい。 The embodiment of FIG. 3 differs from the embodiment shown in FIG. 1 in that a buffer tank 86 and a buffer pump 87 are installed between the cooler 31 and the absorption tower 20. When the amine absorbing liquid is supplied to the reclaimer 94, the water levels of the absorption tower 20, the regeneration tower 40, and the reboiler 60 are decreased by the amount supplied to the reclaimer 94. If there is no problem in operation, the operation of the CO 2 capture facility can be continued with the water level lowered. However, if the capacity of the reclaimer 94 is large and the decrease in the main water level affects the operation of the CO 2 capture facility, the reclaimer 94 When supplying the amine absorbing liquid to the water, the buffer pump 87 is started and the flow rate adjusting valve 88 is operated to keep the water level constant. Since the water level rises after the operation of the reclaimer 94 is started, the shutoff valve 89 may be opened to keep the water level of the absorption tower 20 and the like constant.
１：ボイラ、２：脱硝装置、３：エアヒーター、４：乾式電気集塵装置、５：湿式脱硫装置、６：脱硫出口排ガス、２０：CO2吸収塔、３１：冷却器、３３：吸収塔抜出しポンプ、３４：熱交換器、４０：CO2再生塔、５１：再生塔液溜め部、５２：リボイラ液供給配管、５３：冷却水、６０：リボイラ、６１：蒸気供給配管、６２：蒸気、６６：再生塔液抜出し配管、８１：圧力計、８２：圧力調整弁、８３：冷却器、８４：流量調整弁、８５：温度計、８６：バッファタンク、８７：バッファポンプ、８８：調整弁、８９：遮断弁、９１：遮断弁、９２：流量計、９３：ポンプ、９４：リクレーマ、９５：レベル検出器、９６：蒸気供給配管、９７：アミン吸収液蒸気配管、９８：遮断弁、９９：廃アミン配管、１００：遮断弁、１０１：廃アミンタンク。 1: boiler, 2: denitration device, 3: air heater, 4: dry electrostatic precipitator, 5: wet desulfurization device, 6: exhaust gas from desulfurization outlet, 20: CO 2 absorption tower, 31: cooler, 33: absorption tower Extraction pump, 34: heat exchanger, 40: CO 2 regeneration tower, 51: regeneration tower liquid reservoir, 52: reboiler liquid supply piping, 53: cooling water, 60: reboiler, 61: steam supply piping, 62: steam, 66: regeneration tower liquid extraction piping, 81: pressure gauge, 82: pressure regulating valve, 83: cooler, 84: flow regulating valve, 85: thermometer, 86: buffer tank, 87: buffer pump, 88: regulating valve, 89: shut-off valve, 91: shut-off valve, 92: flow meter, 93: pump, 94: reclaimer, 95: level detector, 96: steam supply pipe, 97: amine absorption liquid steam pipe, 98: shut-off valve, 99: Waste amine piping, 100: shut-off valve, 101: Amine tank.

Claims (6)

  1. 化石燃料の燃焼装置から排出される排ガス中の硫黄酸化物を排煙脱硫装置で除去した後、二酸化炭素（CO2）吸収塔内でアミン吸収液と接触させて排ガス中のCO2を吸収し、次いで該CO2を吸収した吸収液を加熱して再生塔内でCO2を離脱させ、CO2離脱後の吸収液をリボイラを介して昇温した後、再生塔に循環すると共に、再生塔から抜き出したアミン吸収液を該再生塔に供給するアミン吸収液と熱交換した後、前記吸収塔に循環するCO2化学吸収設備と、該再生塔からアミン吸収液を抜き出し、該アミン吸収液中に蓄積した熱安定性塩を蒸留法によって除去した後、発生したアミン吸収液の蒸気を前記再生塔に供給する吸収液再生装置とを有するCO2化学吸収システムにおいて、該アミン吸収液再生装置から発生する蒸気が、前記再生塔に供給する前に、CO2化学吸収システム系内のアミン吸収液を冷媒源とし、前記リボイラの加熱蒸気と同程度の温度および圧力になるように制御することを特徴とするCO2化学吸収システムの制御方法。 After removing the sulfur oxides in the exhaust gas discharged from the fossil fuel combustion device with the flue gas desulfurization device, the carbon dioxide (CO 2 ) absorption tower is brought into contact with the amine absorption liquid to absorb the CO 2 in the exhaust gas. , then after releasing the CO 2 absorbing liquid that has absorbed the CO 2 in the heated regeneration tower, the absorbing solution after CO 2 leaving to warm through the reboiler, the circulating regeneration tower, regeneration tower After exchanging heat with the amine absorption liquid supplied to the regeneration tower, the amine absorption liquid extracted from the CO 2 chemical absorption equipment circulating to the absorption tower, and extracting the amine absorption liquid from the regeneration tower, the amine absorption liquid In a CO 2 chemical absorption system having an absorbent regenerator for supplying vapor of the generated amine absorbent to the regeneration tower after removing the heat-stable salt accumulated in the distillation method, from the amine absorbent regenerator The generated steam is supplied to the regeneration tower. Before, the amine absorbing solution in a CO 2 chemical absorption system based a source of coolant, the control method of the CO 2 chemical absorption system and controls so that the temperature and pressure of the same degree as the heated steam of the reboiler .
  2. 前記再生塔からCO2吸収塔に循環される、前記熱交換した後のアミン吸収液を分岐し、前記蒸気の温度制御用の冷媒源とすることを特徴とする請求項１記載の方法。 The method according to claim 1, wherein the heat-exchanged amine absorption liquid circulated from the regeneration tower to a CO 2 absorption tower is branched to serve as a refrigerant source for controlling the temperature of the vapor.
  3. 前記熱交換した後のアミン吸収液を前記吸収液再生装置内に直接噴霧して前記蒸気を冷却することを特徴とする請求項２記載の方法。 3. The method according to claim 2, wherein the steam is cooled by spraying the amine absorbent after the heat exchange directly into the absorbent regenerator.
  4. 前記熱交換した後のアミン吸収液を、熱交換器を介して前記蒸気と熱交換させ、該蒸気を間接的に冷却することを特徴とする請求項２記載の方法。 The method according to claim 2, wherein the heat-exchanged amine absorption liquid is heat-exchanged with the steam via a heat exchanger, and the steam is indirectly cooled.
  5. 前記吸収塔、再生塔、およびリボイラの水位が下がらないように、アミン吸収液の配管系内にバッファタンクを設置し、前記水位を制御することを特徴とする請求項１ないし４のいずれかに記載の方法。 5. The water level is controlled by installing a buffer tank in the piping system of the amine absorption liquid so that the water levels of the absorption tower, the regeneration tower, and the reboiler do not drop. The method described.
  6. 前記CO2化学吸収システムを運用したままの状態で、前記制御を行なうことを特徴とする請求項１ないし５のいずれかに記載の方法。 The method according to claim 1, wherein the control is performed while the CO 2 chemical absorption system is operated.
PCT/JP2011/076272 2010-11-16 2011-11-15 Method and device for controlling system for chemically absorbing carbon dioxide WO2012067101A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010255782 2010-11-16
JP2010-255782 2010-11-16

Publications (1)

Publication Number Publication Date
WO2012067101A1 true WO2012067101A1 (en) 2012-05-24

Family

ID=46084027

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/076272 WO2012067101A1 (en) 2010-11-16 2011-11-15 Method and device for controlling system for chemically absorbing carbon dioxide

Country Status (1)

Country Link
WO (1) WO2012067101A1 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2676717A2 (en) * 2012-06-20 2013-12-25 Kabushiki Kaisha Toshiba Carbon dioxide recovery device and carbon dioxide recovery method
FR3027819A1 (en) * 2014-11-04 2016-05-06 Ifp Energies Now METHOD FOR DEACIDIFYING A GASEOUS EFFLUENT BY AN ABSORBENT SOLUTION WITH STEAM INJECTION IN THE REGENERATED ABSORBENT SOLUTION AND DEVICE FOR CARRYING OUT SAID METHOD
EP3047893A4 (en) * 2013-11-05 2016-10-19 Mitsubishi Heavy Ind Ltd REGENERATION DEVICE AND RECOVERY METHOD AND DEVICE FOR CO2, H2S, OR BOTH
WO2019078168A1 (en) * 2017-10-20 2019-04-25 三菱重工エンジニアリング株式会社 Reclaiming device and reclaiming method
JP2019076810A (en) * 2017-10-20 2019-05-23 三菱重工エンジニアリング株式会社 Acidic gas removal device and acidic gas removal method
WO2020118088A1 (en) * 2018-12-06 2020-06-11 Schlumberger Technology Corporation A method and system for removing contaminants in gas using a liquid scavenger
US10794167B2 (en) 2018-12-04 2020-10-06 Schlumberger Technology Corporation Method and system for removing contaminants from a gas stream using a liquid absorbent
CN114397922A (en) * 2021-09-29 2022-04-26 北京百利时能源技术股份有限公司 Temperature control system of carbon dioxide capture reboiler of coal-fired power plant
CN115055423A (en) * 2021-08-16 2022-09-16 济南惠成达科技有限公司 Cleaning method and application of absorption tower and regeneration tower

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003053134A (en) * 2001-08-21 2003-02-25 Kansai Electric Power Co Inc:The Desulfurization and decarbonation method
JP2008221166A (en) * 2007-03-14 2008-09-25 Mitsubishi Heavy Ind Ltd CO2 recovery device and waste extraction method
JP2010227742A (en) * 2009-03-26 2010-10-14 Babcock Hitachi Kk Apparatus and method for treating flue gas
JP2011208846A (en) * 2010-03-29 2011-10-20 Hitachi Ltd Boiler apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003053134A (en) * 2001-08-21 2003-02-25 Kansai Electric Power Co Inc:The Desulfurization and decarbonation method
JP2008221166A (en) * 2007-03-14 2008-09-25 Mitsubishi Heavy Ind Ltd CO2 recovery device and waste extraction method
JP2010227742A (en) * 2009-03-26 2010-10-14 Babcock Hitachi Kk Apparatus and method for treating flue gas
JP2011208846A (en) * 2010-03-29 2011-10-20 Hitachi Ltd Boiler apparatus

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2676717A2 (en) * 2012-06-20 2013-12-25 Kabushiki Kaisha Toshiba Carbon dioxide recovery device and carbon dioxide recovery method
CN103505986A (en) * 2012-06-20 2014-01-15 株式会社东芝 Carbon dioxide recovery device and carbon dioxide recovery method
EP2676717A3 (en) * 2012-06-20 2014-01-22 Kabushiki Kaisha Toshiba Carbon dioxide recovery device and carbon dioxide recovery method
AU2013206428B2 (en) * 2012-06-20 2015-08-27 Kabushiki Kaisha Toshiba Carbon dioxide recovery device and carbon dioxide recovery method
US9248403B2 (en) 2012-06-20 2016-02-02 Kabushiki Kaisha Toshiba Carbon dioxide recovery device and carbon dioxide recovery method
US10137415B2 (en) 2013-11-05 2018-11-27 Mitsubishi Heavy Industries Engineering, Ltd. Reclaiming device, method, and recovery unit of CO2, H2S, or both of CO2 and H2S
EP3047893A4 (en) * 2013-11-05 2016-10-19 Mitsubishi Heavy Ind Ltd REGENERATION DEVICE AND RECOVERY METHOD AND DEVICE FOR CO2, H2S, OR BOTH
EP3017857A1 (en) * 2014-11-04 2016-05-11 IFP Energies nouvelles Method for deacidifying a gaseous effluent with an absorbent solution with steam injection in the regenerated absorbent solution and device for implementing same
FR3027819A1 (en) * 2014-11-04 2016-05-06 Ifp Energies Now METHOD FOR DEACIDIFYING A GASEOUS EFFLUENT BY AN ABSORBENT SOLUTION WITH STEAM INJECTION IN THE REGENERATED ABSORBENT SOLUTION AND DEVICE FOR CARRYING OUT SAID METHOD
US10137410B2 (en) 2014-11-04 2018-11-27 IFP Energies Nouvelles Method of deacidizing a gaseous effluent by an absorbent solution with vapor injection into the regenerated absorbent solution and device for implementing same
JP2019076809A (en) * 2017-10-20 2019-05-23 三菱重工エンジニアリング株式会社 Reclaiming apparatus and reclaiming method
JP2019076810A (en) * 2017-10-20 2019-05-23 三菱重工エンジニアリング株式会社 Acidic gas removal device and acidic gas removal method
WO2019078168A1 (en) * 2017-10-20 2019-04-25 三菱重工エンジニアリング株式会社 Reclaiming device and reclaiming method
JP6998174B2 (en) 2017-10-20 2022-01-18 三菱重工エンジニアリング株式会社 Acid gas removal device and acid gas removal method
US10794167B2 (en) 2018-12-04 2020-10-06 Schlumberger Technology Corporation Method and system for removing contaminants from a gas stream using a liquid absorbent
WO2020118088A1 (en) * 2018-12-06 2020-06-11 Schlumberger Technology Corporation A method and system for removing contaminants in gas using a liquid scavenger
CN115055423A (en) * 2021-08-16 2022-09-16 济南惠成达科技有限公司 Cleaning method and application of absorption tower and regeneration tower
CN114397922A (en) * 2021-09-29 2022-04-26 北京百利时能源技术股份有限公司 Temperature control system of carbon dioxide capture reboiler of coal-fired power plant
CN114397922B (en) * 2021-09-29 2023-03-14 北京百利时能源技术股份有限公司 Temperature control system of carbon dioxide capture reboiler of coal-fired power plant

Similar Documents

Publication Publication Date Title
WO2012067101A1 (en) Method and device for controlling system for chemically absorbing carbon dioxide
JP5636306B2 (en) Control method for CO2 chemical absorption system
JP5725992B2 (en) CO2 recovery equipment
JP5868741B2 (en) Acid gas removal device
JP5959882B2 (en) Carbon dioxide chemical absorption system in combustion exhaust gas
WO2011132660A1 (en) Exhaust gas treatment system having carbon dioxide removal device
JP5639814B2 (en) Thermal power generation system with CO2 removal equipment
JP5855130B2 (en) Carbon dioxide chemical absorption system with steam recompression equipment
JP5762253B2 (en) Control method for CO2 chemical absorption system
WO2013039041A1 (en) Co2 recovery device and co2 recovery method
WO2013161574A1 (en) Co2 recovery device, and co2 recovery method
JP2011194292A (en) Method and apparatus for treating exhaust gas
JP2013059727A (en) Co2 recovery device and co2 recovery method
JP5976817B2 (en) Heat recovery system and heat recovery method
JP2013202612A (en) Exhaust gas treatment system
WO2022044487A1 (en) Carbon dioxide recovery system
WO2014046147A1 (en) Steam providing system and co2 recovery facilities provided with same
Tsujiuchi et al. CO 2 recovery unit and CO 2 recovery method

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11841550

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11841550

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP