WO2012131951A1 - 排ガス処理システムおよび排ガス処理方法 - Google Patents
排ガス処理システムおよび排ガス処理方法 Download PDFInfo
- Publication number
- WO2012131951A1 WO2012131951A1 PCT/JP2011/058099 JP2011058099W WO2012131951A1 WO 2012131951 A1 WO2012131951 A1 WO 2012131951A1 JP 2011058099 W JP2011058099 W JP 2011058099W WO 2012131951 A1 WO2012131951 A1 WO 2012131951A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- water
- exhaust gas
- seawater
- treatment system
- reduced
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
-
- 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
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
-
- 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
- B01D2252/10—Inorganic absorbents
- B01D2252/103—Water
- B01D2252/1035—Sea water
-
- 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
- B01D53/343—Heat recovery
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/08—Seawater, e.g. for desalination
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/18—Nature of the water, waste water, sewage or sludge to be treated from the purification of gaseous effluents
Definitions
- the present invention relates to an exhaust gas treatment system and an exhaust gas treatment method provided with a wet desulfurization device and a fresh water generator, and more particularly to an exhaust gas treatment system and an exhaust gas treatment method for supplying makeup water from the fresh water generator to the wet desulfurization device.
- a flue gas desulfurization unit is installed in power generation boilers that burn fuels that contain a relatively large amount of sulfur, such as coal, in order to remove sulfur oxides (SOx) in exhaust gases that cause air pollution and acid rain. It has been.
- the wet limestone-gypsum method which is one of the desulfurization methods, has features such as a high desulfurization rate and the ability to use recovered gypsum as a valuable material and is widely used.
- such a wet desulfurization apparatus has a problem that a large amount of industrial water is required.
- the chloride ions contained in the dehydrated filtrate are concentrated, and when the concentration exceeds a certain level, the desulfurization efficiency of the limestone slurry is reduced. In order to avoid this concentration, it is necessary to drain part of the dehydrated filtrate and maintain the chloride ion concentration in the system below the planned value.
- the wet desulfurization apparatus requires a large amount of make-up water, and therefore requires a fresh water generator.
- an existing fresh water generator may not be applied as it is.
- the main purpose of the fresh water generator is supply of makeup water
- demands for cost reduction such as installation cost and operation cost become stricter than those of existing fresh water generators.
- the supply amount (fresh water amount) of the fresh water generator can be reduced, and the operation cost can be reduced.
- Patent Document 1 discloses a conventional technique related to reducing the consumption of makeup water.
- the amount of water evaporated in the limestone slurry can be reduced by cooling the exhaust gas at the front stage of the absorption tower with a heat exchanger. Further, by cooling the exhaust gas in contact with seawater indirectly after the absorption tower, the water evaporated in the absorption tower can be condensed and recovered and reused as makeup water. Thus, the consumption of makeup water can be reduced by reducing the evaporation amount in the absorption tower and the moisture released to the atmosphere.
- the heated seawater for cooling is supplied to a fresh water generator using an electrodialysis method, the energy consumed by the fresh water generator decreases as the water temperature rises, so that fresh water can be produced with high efficiency.
- this fresh water as makeup water, the supply of fresh water from outside the system can be reduced.
- An object of the present invention is to provide an exhaust gas treatment system and an exhaust gas treatment method capable of solving the above-described conventional problems and reducing the cost when combining a desulfurization apparatus and a fresh water generation apparatus using a membrane treatment method. is there.
- the present invention provides a wet desulfurization device that removes sulfur oxides contained in the exhaust gas of a boiler, a pump that pressurizes seawater, and seawater sent from this pump.
- An exhaust gas treatment system comprising: a fresh water generator having a membrane treatment device that separates water into non-permeated water; and a makeup water supply passage that supplies at least a part of the permeated water as makeup water to the desulfurization device;
- a gas cooler having an exhaust gas cooling function for cooling the exhaust gas flowing into the desulfurization apparatus with seawater used in the fresh water generator, and a seawater heating function for heating the seawater with the heat of the exhaust gas when cooling the exhaust gas Is provided.
- the moisture contained in the exhaust gas is condensed and supplied to the wet desulfurization device by the exhaust gas cooling function. Moisture discharged outside the system is reduced, the amount of water produced by the fresh water generator is reduced, and energy consumption is also reduced.
- the apparatus further comprises a water temperature adjusting means for adjusting the water temperature of the seawater heated by the seawater heating function and supplying the seawater whose water temperature has been adjusted to the pump.
- the seawater warming is allowed by the water temperature adjusting means until the chloride ion concentration upper limit value of the makeup water is reached. As the water temperature rises, energy consumption during fresh water production will decrease.
- the fresh water generator is a first pump that boosts seawater, and a first membrane treatment that separates seawater sent from the first pump into permeated water and non-permeated water.
- the makeup water supply channel supplies first-stage permeate and second-stage non-permeate to the desulfurization apparatus.
- the desalination capacity of the membrane treatment device is somewhat reduced, so there are restrictions on the use when using permeated water other than makeup water.
- the application range of the second-stage permeated water is widened, and the exhaust gas treatment system can have versatility.
- the exhaust gas cooling function of the gas cooler cools the exhaust gas with the first-stage permeated water.
- the second gas cooler that further cools the exhaust gas discharged from the wet desulfurization device with seawater used in the fresh water generator and condenses and removes moisture contained in the exhaust gas.
- a second make-up water supply path for supplying at least a part of the condensed water from the second gas cooler to the desulfurization device as make-up water.
- the amount of water produced is remarkably reduced by supplying a part of the water contained in the exhaust gas discharged outside the system to the desulfurization device as condensed water. This also reduces energy consumption.
- the second gas cooler that further cools the exhaust gas discharged from the wet desulfurization apparatus with seawater used in the fresh water generator and condenses and removes moisture contained in the exhaust gas. And a condensed water mixing path for mixing at least a part of condensed water by the second gas cooler with seawater fed to the membrane treatment device.
- the present invention increases the pressure of seawater and separates the seawater into permeate and non-permeate by a membrane treatment device, and the permeate obtained in the fresh water step.
- the exhaust gas treatment method comprising an exhaust gas desulfurization step for removing substances, the exhaust gas flowing into the desulfurization device in the exhaust gas desulfurization step is cooled by seawater used in the fresh water generation step, and when the exhaust gas is cooled, An exhaust gas cooling / seawater heating step for heating seawater with the heat of the exhaust gas is provided.
- the present invention it is possible to reduce costs when combining a desulfurization apparatus and a fresh water generation apparatus using a membrane treatment method. Thereby, the exhaust gas treatment system provided with the wet desulfurization apparatus can be provided even in an area where the fresh water source is scarce.
- FIG. 1 is a configuration of an exhaust gas treatment system (first embodiment). It is a structure of an exhaust gas treatment system (2nd Embodiment). It is a functional block diagram of a controller. It is a flowchart which shows the processing content of a controller. It is a conceptual diagram explaining an effect.
- This is a configuration of an exhaust gas treatment system (first modification). This is a configuration of an exhaust gas treatment system (second modification). This is a configuration of an exhaust gas treatment system (third modified example).
- It is a structure of an exhaust gas treatment system (4th modification). It is a structure of an exhaust gas treatment system (3rd Embodiment). It is a structure of an exhaust gas treatment system (4th Embodiment). It is a conceptual diagram explaining an effect.
- This is a configuration of an exhaust gas treatment system (fifth embodiment). It is a structure of an exhaust gas treatment system (5th modification). This is a configuration of an exhaust gas treatment system (sixth modification).
- FIG. 1 shows the configuration of an exhaust gas treatment system according to the first embodiment.
- the exhaust gas treatment system includes a wet desulfurization device and a fresh water generator.
- the exhaust gas 1 from the boiler is removed by the dust collector 10 and cooled by the gas cooler 11, and then flows into the absorption tower 12.
- the exhaust gas 1 is sprayed with a limestone slurry 36, and SOx is removed by a gas-liquid reaction with the limestone slurry 36.
- the exhaust gas 1 emitted from the absorption tower 12 is discharged from the chimney 13 into the atmosphere.
- the limestone slurry 36 having absorbed SOx in the absorption tower 12 is sent to the gypsum dewatering machine 15 and separated into gypsum 28 and dehydrated filtrate 29.
- the gypsum 28 is carried out and reused outside the system.
- a part of the dehydrated filtrate 29 is sent to a wastewater treatment device (not shown) as desulfurization wastewater 30.
- the remaining dehydrated filtrate 29 is injected into the limestone slurry supply device 16, mixed with limestone, becomes a supplemented limestone slurry 37, and is supplied to the absorption tower 12.
- the wet desulfurization apparatus requires a large amount of industrial water.
- the desulfurization waste water 30, the moisture contained in the exhaust gas 1 discharged into the atmosphere, the crystal water in the gypsum 28, etc. are discharged outside the system. Accordingly, the makeup water 31 is supplied from the makeup water tank 18 to the absorption tower 12 as needed.
- the seawater 20 pumped up by the intake pump 6 is subjected to removal of solid / soluble substances by the pretreatment device 7, or the water temperature / pH and the like are adjusted to become pretreated water 21.
- the pretreated water 21 is heated by the heat of the exhaust gas 1 in the gas cooler 11, then pressurized by the high pressure pump 8, flows into the high pressure reverse osmosis membrane 9, and is separated into the concentrated water 22 and the permeated water 23.
- a part of the permeated water 23 flows into the makeup water tank 18.
- the remaining permeated water 23 is pressurized by the low pressure pump 17 and flows into the low pressure reverse osmosis membrane 14, and is separated into the concentrated water 24 and the permeated water 25.
- Part of the concentrated water 24 flows into the makeup water tank 18.
- Part of the permeated water 25 flows into the makeup water tank 18.
- the remaining permeated water is used as fresh water 26 outside the system as a raw material for drinking water or seal water for auxiliary equipment such as an on-site pump.
- the makeup water 31 from the makeup water tank 18 is supplied to the absorption tower 12 through the makeup water supply path 51.
- the fresh water generator can supply the makeup water 31.
- the gas cooler 11 cools the exhaust gas 1 flowing into the absorption tower 12 by the pretreated water 21 (pretreated seawater 20) (exhaust gas cooling function 11a) and warms the pretreated water 21 by the heat of the exhaust gas 1. (Seawater heating function 11b), operates as a heat exchanger.
- the water contained in the exhaust gas 1 is condensed by the gas cooling by the gas cooler 11 and supplied to the absorption tower 12. As a result, the moisture contained in the exhaust gas 1 discharged from the chimney 13 is reduced. Therefore, the required amount of makeup water is reduced and the amount of fresh water is also reduced. This also reduces energy consumption.
- the permeation flow rate in the high-pressure reverse osmosis membrane 9 with respect to a constant pressure increases.
- the power of the pump 8 required per unit flow rate is reduced. That is, the water can be generated efficiently and the operation cost can be reduced. Similar effects can be obtained with the low-pressure pump 17 and the low-pressure reverse osmosis membrane 14, and the operation cost can be further reduced.
- the desalting capacity of the high-pressure reverse osmosis membrane 9 slightly decreases. Therefore, the chloride ion concentration in the permeated water 23 is slightly high.
- the desalination process is further performed by the low-pressure reverse osmosis membrane 14, and the makeup water 31 is not required to have a desalting level as that of drinking water (to use as drinking water, the chloride ion concentration needs to be lower). And the like, even if the desalting capacity of the high-pressure reverse osmosis membrane 9 is slightly reduced, there is no problem.
- Second Embodiment ⁇ New issues As described above, as the water temperature rises, the energy consumption during fresh water production is reduced, while the desalting treatment capacity of the high-pressure reverse osmosis membrane 9 is slightly reduced. That is, there is a trade-off between energy consumption reduction (energy efficiency improvement) and desalting treatment capacity.
- the replenishing water 31 is not required to have a desalting level as much as that of drinking water, it needs to be below a predetermined level (set value) of chloride ion concentration. If the temperature is heated more than necessary, the chloride ion concentration exceeds the set value, which may not be used as makeup water for the desulfurization apparatus.
- the main purpose of the fresh water generator is to supply makeup water 31, but there is also a desire to use fresh water 26 effectively.
- the chloride ion concentration of the fresh water 26 it is also necessary to lower the chloride ion concentration (set value) of the makeup water 31.
- the temperature of the seawater 20 varies throughout the year. That is, it is high in summer and low in winter.
- the temperature of the supply water to the high-pressure reverse osmosis membrane 9 also varies, and the chloride ion concentration of the makeup water 31 also varies. If the chloride ion concentration of the makeup water 31 exceeds the set value, it cannot be used as makeup water for the desulfurization apparatus. On the other hand, if the chloride ion concentration of the makeup water 31 is lower than the set value, there is room for improvement in energy efficiency.
- FIG. 2 shows the configuration of the exhaust gas treatment system according to the second embodiment.
- a bypass valve 40 and a drain valve 41 are added to the configuration of the first embodiment.
- the bypass valve 40 is provided in the supply path of the pretreatment water 21 to the gas cooler 11. A part of the pretreated water 21 is supplied directly to the pump 8 without being supplied to the gas cooler 11 via the bypass path branched by the bypass valve 40.
- the flow rate ratio between the supply amount Q1 to the gas cooler 11 and the supply amount (bypass amount) Q2 to the bypass passage is controlled by the opening degree of the bypass valve 40.
- the drain valve 41 is provided in the discharge path of the pretreatment water 21 from the gas cooler 11. A part of the pretreated water 21 heated by the gas cooler 11 is discharged out of the system (for example, in seawater) through the drainage channel branched by the drainage valve 41. The amount of drainage Qout discharged from the drainage channel is controlled by the opening degree of the drainage valve 41.
- the exhaust gas treatment system controls the opening degree of the bypass valve 40 (that is, the bypass amount Q2), the opening degree of the drain valve 41 (that is, the drainage amount Qout), and the intake amount Qin of the seawater 20 by the intake pump 6 to control the high pressure reverse osmosis membrane.
- the temperature Tf of the feed water to 9 is adjusted.
- controller 50 may perform water temperature adjustment control. In that case, the controller 50 and related components are added to the configuration of FIG.
- FIG. 3 is a functional block diagram of the controller 50.
- the controller 50 receives the seawater temperature Tin from the temperature sensor 46 provided at the seawater intake, the exhaust gas temperature Tg and the exhaust gas flow rate Qg from the exhaust gas state sensor 47 provided at the inlet of the gas cooler 11, and the chloride ion concentration sensor 48.
- the chloride ion concentration measurement value Csm of the makeup water 31 and the chloride ion concentration measurement value Cpm of the fresh water 26 are input from the input terminal 49 to the chloride ion concentration setting value Cst of the makeup water 31 and the chloride ion concentration setting value Cpt of the fresh water 26. Enter the required amount of makeup water and freshwater.
- a predetermined calculation is performed to output the water intake amount Qin to the intake pump 6, the bypass amount Q2 to the bypass valve 40, and the drainage amount Qout to the drain valve 41 to control the intake pump 6, the bypass valve 40, and the drain valve 41.
- FIG. 4 is a flowchart showing the processing contents of the controller 50.
- step S11 When the makeup water chloride ion concentration setting value Cst, fresh water chloride ion concentration setting value Cpt, makeup water requirement amount, and fresh water requirement amount are set based on the operator's input instructions (step S11), these values and the high-pressure reverse osmosis membrane Based on the characteristic curve 9 (see FIG. 5), the set flow rate Qf and temperature Tf of the supply water to the high-pressure reverse osmosis membrane 9 are calculated (step S12).
- the temperature Tin of the seawater 20 is input (step S13), the exhaust gas temperature Tg and the exhaust gas flow rate Qg are input (step S14), and the seawater to the gas cooler 11 is based on these values and the exhaust gas temperature after cooling.
- a supply amount Q1 of 20 (pretreated water 21) and a temperature T1 after exhaust gas cooling (seawater warming) are calculated (step S15).
- Equation 1 is satisfied regarding the flow rate
- Expression 2 is satisfied at the bypass path merging point downstream of the drain valve 41.
- Qin Q1 + Q2 (1)
- Qf (Q1-Qout) + Q2 (2)
- Expression 1 and Expression 2 are expressed as Expression 3 from the viewpoint of the entire system.
- Equation 4 is satisfied with respect to the water temperature at the junction.
- step S17 Based on the calculation result of step S16, the intake pump 6, the bypass valve 40, and the drain valve 41 are controlled (step S17).
- Step S18 Enter makeup water chloride ion concentration measurement value Csm and freshwater chloride ion concentration measurement value Cpm (step S18), and determine whether the makeup water chloride ion concentration setting value Cst and freshwater chloride ion concentration setting value Cpt match. (Step S19). If it is a predetermined concentration, the control is terminated. If it is not a predetermined concentration, the control is repeated until the predetermined concentration is reached.
- Operation For example, when it is desired to lower the chloride ion concentration of the makeup water 31 and the chloride ion concentration of the fresh water 26, the bypass valve 40 is opened. Since the flow rate Q1 of the heated water decreases and the flow rate Q2 of the unheated water increases, the temperature Tf of the water supplied to the high pressure reverse osmosis membrane 9 decreases, and the characteristic curve of the high pressure reverse osmosis membrane 9 (FIG. 5 According to the reference), the measured chloride ion concentration of the makeup water 31 and the chloride ion concentration of the fresh water 26 are also lowered.
- the flow rate Q1 decreases while the water intake Qin is constant, the cooling performance of the gas cooler 11 cannot be maintained. Therefore, while maintaining the flow rate Q1, the water intake Qin and the flow rate Q2 are increased, the drain valve 41 is opened, and a part of the heated water is drained. As a result, the water temperature can be adjusted while maintaining the cooling performance of the gas cooler 11.
- FIG. 5 is a conceptual diagram for explaining the effect of this embodiment.
- the horizontal axis represents the temperature of the water supplied to the reverse osmosis membrane, and the vertical axis represents the energy consumed during fresh water production and the chloride ion concentration of the permeated water. As the water temperature rises, the energy consumed during fresh water production is reduced, while the desalting capacity of the reverse osmosis membrane is slightly reduced.
- the make-up water 31 is not required to have the same desalination level as drinking water, and the chloride ion concentration of the permeated water can be set to an allowable upper limit value. That is, heating is allowed until point A is shown.
- the water temperature can be adjusted, and the water can be heated to the point A in the figure.
- the energy consumed during fresh water production is reduced to point B in the figure. As a result, the water can be generated efficiently and the operation cost can be reduced.
- the second embodiment is obtained by adding a water temperature adjusting means to the configuration of the first embodiment, and the effect of the first embodiment can also be obtained.
- FIG. 6 shows the configuration of the exhaust gas treatment system according to the first modification. You may arrange
- the pretreatment is a membrane treatment using an MF membrane or a UF membrane, a reduction in energy consumption of the intake pump 6 can be expected as the water temperature rises.
- the pretreatment water 21 is discharged from the drain valve 41.
- the amount of the pretreatment device 7 is reduced by pretreatment of the discharged seawater 20. Operation costs can be reduced.
- the pretreatment device 7 is arranged at the front stage of the gas cooler 11 to maintain the gas cooler 11 as in the second embodiment. Administratively desirable.
- FIG. 7 shows the configuration of the exhaust gas treatment system according to the second modification.
- the electric dust collector 10 may be disposed at the rear stage of the gas cooler 11. In this case, since the temperature of the exhaust gas 1 flowing into the electric dust remover 10 decreases, an improvement in the dust removal performance of the electric dust collector 10 can be expected. However, problems such as dust sticking to the inside of the electrostatic precipitator 10 occur when the exhaust gas temperature falls below a certain temperature. Therefore, it is necessary to adjust the amount of cooling water in the gas cooler 11 so as to maintain the exhaust gas temperature within a predetermined range.
- FIG. 8 shows the configuration of the exhaust gas treatment system according to the third modification.
- the concentrated water 24 separated by the low-pressure reverse osmosis membrane 14 may be directly supplied to the absorption tower 12 without using the makeup water tank 18.
- the makeup water 31 from the makeup water tank 18 is supplied to the absorption tower 12 through the makeup water supply path 51 by the pressure of a pump 52 (not shown).
- the concentrated water 24 separated by the low-pressure reverse osmosis membrane 14 remains pressurized by the low-pressure pump 17 and can be supplied to the absorption tower 12 without going through the makeup water tank 18 and the makeup water supply path 51.
- the water flow rate of the makeup water supply passage 51 is reduced, and the energy consumption of the pump 52 can be expected to be reduced.
- FIG. 9 shows the configuration of the exhaust gas treatment system according to the fourth modification.
- the low pressure pump 17 and the low pressure reverse osmosis membrane 14 may not be included. In this case, it is possible not only to reduce the operation cost such as the energy consumption of the low-pressure pump and the trouble of washing and replacing the low-pressure reverse osmosis membrane, but also to reduce the installation cost thereof.
- the gas cooler 11 cools the exhaust gas 1 flowing into the absorption tower 12 with the pretreated water 21 (pretreated seawater 20), and also pretreats it with the heat of the exhaust gas 1.
- the water 21 is heated and the heated water is supplied to the high-pressure pump 8 and the high-pressure reverse osmosis membrane 9. That is, seawater 20 (precisely, pretreated water 21) passes through the gas cooler 11, and the seawater contact portion is required to have high corrosion resistance. Thereby, the subject concerning the installation cost of the gas cooler 11 arises.
- FIG. 10 shows the configuration of the exhaust gas treatment system according to the third embodiment.
- a gas cooler 11 is disposed at the subsequent stage of the high-pressure reverse osmosis membrane 9.
- the gas cooler 11 cools the exhaust gas 1 flowing into the absorption tower 12 with the permeated water 23 separated by the high-pressure reverse osmosis membrane 9 and warms the permeated water 23 with the heat of the exhaust gas 1.
- the heated permeated water 23 is pressurized by the low pressure pump 17 and flows into the low pressure reverse osmosis membrane 14.
- the temperature control valve 42 utilizes the permeated water 23 in a system.
- the water flow rate of the temperature control valve 42 corresponds to the drainage amount Qout in the second embodiment.
- the chloride ion concentration of the seawater 20 passing through the gas cooler 11 is about 35000 mg / l.
- the chloride ion concentration of the permeated water 23 that passes through the gas cooler 11 in this embodiment is about 200 to 300 mg / l, and the corrosion resistance is required as much as the first and second embodiments.
- the installation cost of the gas cooler 11 can be reduced.
- Total cost reduction can be achieved by reducing installation cost and operation cost.
- the chloride ion concentration of the permeated water 23 separated by the high-pressure reverse osmosis membrane 9 is lower than that in the first and second embodiments.
- the chloride ion concentration of the fresh water 26 is also lower than in the first and second embodiments (see FIG. 5). Thereby, the application range of the fresh water 26 spreads and the fresh water 26 can be used effectively.
- the exhaust gas 1 from which SOx has been removed by the absorption tower 12 is discharged from the chimney 13 into the atmosphere.
- the exhaust gas 1 discharged out of the system contains a large amount of water, which is a cause of the need for a large amount of makeup water 31.
- a problem relating to operation costs arises.
- FIG. 11 shows the configuration of the exhaust gas treatment system according to the fourth embodiment.
- a gas cooler (second gas cooler) 43 is added to the configuration of the second embodiment.
- the gas cooler 43 is provided at the rear stage of the absorption tower 12.
- the operation of the wet desulfurization apparatus including the absorption tower 12 will be described.
- the exhaust gas 1 from the boiler is removed by the dust collector 10 and cooled by the gas cooler 11, and then flows into the absorption tower 12.
- the exhaust gas 1 is sprayed with a limestone slurry 36, and SOx is removed by a gas-liquid reaction with the limestone slurry 36.
- the water in the limestone slurry 36 evaporates due to the heat of the exhaust gas 1.
- the exhaust gas 1 containing moisture is cooled by the gas cooler 43, and the moisture is condensed and removed.
- the exhaust gas 1 from which moisture has been removed is discharged from the chimney 13 into the atmosphere.
- the water condensed by the gas cooler 43 (condensed water 32) flows into the makeup water tank 18 through the makeup water supply path (second makeup water supply path) 53.
- FIG. 12 is a conceptual diagram for explaining the effect of the present embodiment.
- the horizontal axis shows cases 1 to 4, the vertical axis is the amount of water discharged outside the system, the middle is the amount of makeup water required, the lower is the energy consumed during fresh water generation, and the bottom is the elements of each case Shows about.
- the required amount of makeup water is linked to the amount of water discharged outside the system. That is, if the amount of water discharged out of the system increases, the amount of necessary makeup water increases and the amount of fresh water increases.
- the energy consumption of the pump at the time of fresh water generation depends on the fresh water volume and the temperature of the supplied water. That is, if the amount of water produced decreases, the energy consumption also decreases. As the water temperature rises, the permeation flow rate increases and the energy consumption decreases.
- Case 1 shows a case where none of the elements of gas cooling by the gas cooler 11, heating of the supply water by the gas cooler 11, and replenishment of the condensed water 32 are present.
- Case 2 shows a case where there is only gas cooling by the gas cooler 11.
- the water contained in the exhaust gas 1 is condensed by the gas cooling by the gas cooler 11 and supplied to the absorption tower 12. As a result, the moisture contained in the exhaust gas 1 discharged from the chimney 13 is reduced. Therefore, the required amount of makeup water is reduced and the amount of fresh water is also reduced. This also reduces energy consumption.
- Case 3 shows a case where there are elements of gas cooling by the gas cooler 11 and heating of the feed water by the gas cooler 11. By comparing Case 2 and Case 3, the effect of heating the supply water by the gas cooler 11 will be described.
- the chloride ion concentration in the makeup water 31 also increases. Since the water in the desulfurization apparatus circulates, if the chloride ion concentration of the makeup water 31 increases, the flow rate of the desulfurization waste water 30 also increases to avoid concentration. As a result, if the amount of water discharged out of the system is slightly increased, the required amount of makeup water is also increased, and the amount of water produced is also increased slightly. However, compared to the effect of increasing energy consumption by increasing the amount of water produced, the effect of reducing energy consumption accompanying an increase in water temperature is exceeded, resulting in a decrease in energy consumption.
- Case 4 shows a case where all elements of gas cooling by the gas cooler 11, heating of the supply water by the gas cooler 11, and replenishment of the condensed water 32 are present.
- the high pressure pump 8 and the high pressure reverse osmosis membrane 9 can be miniaturized due to the effects of reducing the amount of water produced and reducing the energy consumption, and the installation cost can also be reduced.
- the high pressure pump 8 pressurizes the pretreated water 21 and supplies it to the high pressure reverse osmosis membrane 9.
- the pretreated water 21 is a pretreated seawater 20 and has a high chloride ion concentration. When the chloride ion concentration is high, energy consumption during fresh water production also increases, which causes problems related to operation costs.
- FIG. 13 shows the configuration of the exhaust gas treatment system according to the fifth embodiment.
- the point which added the gas cooler (2nd gas cooler) 43 to the structure of 2nd Embodiment is the same as 4th Embodiment, the water
- the condensed water 32 may contain a trace amount of heavy metals contained in the exhaust gas 1, but these heavy metals are separated into the concentrated water 22 by the high-pressure reverse osmosis membrane 9 and separated as sludge by wastewater treatment. ⁇ It will be disposed of. For this reason, it is possible to avoid outflow to the water environment such as the ocean.
- FIG. 14 shows the configuration of the exhaust gas treatment system according to the fifth modification.
- the water condensed by the gas cooler 43 (condensed water 32) may be mixed with the seawater 20 in the previous stage of the pretreatment device 7 via the condensed water mixing path 54.
- FIG. 15 shows the configuration of the exhaust gas treatment system according to the sixth modification.
- the makeup water supply path (second makeup water supply path) 53 of the fourth embodiment is added to the configuration of the fifth embodiment. Thereby, the effect of 4th Embodiment and 5th Embodiment is acquired.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Water Supply & Treatment (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Environmental & Geological Engineering (AREA)
- Hydrology & Water Resources (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Life Sciences & Earth Sciences (AREA)
- Nanotechnology (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Treating Waste Gases (AREA)
Abstract
Description
~基本構成・基本動作~
図1は第1実施形態に係る排ガス処理システムの構成である。排ガス処理システムは湿式脱硫装置と造水装置とを備えている。
本実施形態の特徴的構成および動作について説明する。ガス冷却器11は、吸収塔12に流入する排ガス1を前処理水21(前処理された海水20)により冷却する(排ガス冷却機能11a)とともに、排ガス1の熱により前処理水21を加温する(海水加温機能11b)、熱交換器として作動する。
~新たな課題~
上述したように、水温上昇に伴い、造水時の消費エネルギーは低減する一方、高圧逆浸透膜9の脱塩処理能力はやや低下する。すなわち、消費エネルギー低減(エネルギー効率向上)と脱塩処理能力はトレードオフの関係にある。
図2は第2実施形態に係る排ガス処理システムの構成である。第1実施形態の構成に、バイパス弁40と、排水弁41を付加する。
Qin = Q1 + Q2 (1)
Qf =(Q1 - Qout)+Q2 (2)
なお、式1、式2を系全体の観点から見ると式3のようになる。
Qin(=Q1 + Q2)= Qf+Qout (3)
一方、合流点における水温に関し、式4を満たす。
Qf×Tf = (Q1 - Qout)×T1+ Q2×Tin(=T2) (4)
式2と式4より、式5が導き出される。
(T1-Tf)×Q1=(T1-Tf)×Qout+(Tf-Tin)×Q2 (5)
式5を満たし、QoutとQ2の合計量が少なくなるように、最適な排水量Qoutおよびバイパス量Q2を演算する。さらに式1を満たすように取水量Qinを演算する(ステップS16)。
たとえば、補給水31の塩化物イオン濃度および淡水26の塩化物イオン濃度を下げたい場合、バイパス弁40を開く。加温された水の流量Q1が減り、加温されていない水の流量Q2が増えるため、高圧逆浸透膜9への供給水の温度Tfは下がり、高圧逆浸透膜9の特性曲線(図5参照)に従って補給水31の塩化物イオン濃度計測値および淡水26の塩化物イオン濃度も下がる。
図5は本実施形態の効果について説明する概念図である。横軸は逆浸透膜への供給水の水温、縦軸は造水時の消費エネルギーおよび透過水の塩化物イオン濃度を示している。水温上昇に伴い、造水時の消費エネルギーは低減する一方逆浸透膜の脱塩処理能力はやや低下する。
1.図6に第1変形例に係る排ガス処理システムの構成を示す。前処理装置7をガス冷却器11の後段に配置してもよい。この場合,例えば前処理がMF膜やUF膜による膜処理であれば、水温上昇に伴う取水ポンプ6の消費エネルギー低減が期待できる。また、第2実施形態では、前処理水21を排水弁41から排出していたが、第1変形例では、排出後の海水20を前処理することで、前処理装置7の処理量を減らすことができ、運用コストを低減できる。
~新たな課題~
第1実施形態、第2実施形態において、ガス冷却器11は、吸収塔12に流入する排ガス1を前処理水21(前処理された海水20)により冷却するとともに、排ガス1の熱により前処理水21を加温し、加温した水を高圧ポンプ8,高圧逆浸透膜9に供給している。すなわち、ガス冷却器11内を海水20(正確には前処理水21)が通水することになり、海水接触部の材質は高い耐腐食性を要求される。これにより、ガス冷却器11の設置コストにかかる課題が生じる。
図10は第3実施形態に係る排ガス処理システムの構成である。ガス冷却器11が高圧逆浸透膜9の後段に配置されている。ガス冷却器11は、吸収塔12に流入する排ガス1を高圧逆浸透膜9で分離された透過水23により冷却するとともに、排ガス1の熱により透過水23を加温する。加温された透過水23は、低圧ポンプ17で加圧され低圧逆浸透膜14に流入する。
第1実施形態、第2実施形態において、ガス冷却器11内を通水する海水20の塩化物イオン濃度は、35000mg/l程度である。一方、本実施形態におけるガス冷却器11内を通水する透過水23の塩化物イオン濃度は、200~300mg/l程度であり、第1実施形態、第2実施形態ほどは耐腐食性を要求されないため、ガス冷却器11の設置コスト低減を図ることができる。
~課題~
第1実施形態、第2実施形態において、吸収塔12でSOxを除去された排ガス1は、煙突13から大気中に排出される。このとき、系外に排出される排ガス1に多量の水分含まれ、多量の補給水31が必要となる一因となる。補給水31を多量に造水すると、運用コストに係る課題が生じる。
図11は第4実施形態に係る排ガス処理システムの構成である。第2実施形態の構成に、ガス冷却器(第2ガス冷却器)43を付加した。ガス冷却器43は、吸収塔12の後段に設けられている。
図12は本実施形態の効果について説明する概念図である。横軸は、ケース1~4を示し、縦軸は、上段は系外に排出される水分量、中段は必要な補給水量、下段は造水時の消費エネルギー、最下段は各ケースの諸要素について示している。
~課題~
第1実施形態、第2実施形態において、高圧ポンプ8は、前処理水21を加圧し、高圧逆浸透膜9に供給している。前処理水21は海水20を前処理したものであり、塩化物イオン濃度が高い。塩化物イオン濃度が高いと、造水時の消費エネルギーも増加するため、運用コストに係る課題が生じる。
図13は第5実施形態に係る排ガス処理システムの構成である。第2実施形態の構成にガス冷却器(第2ガス冷却器)43を付加した点は第4実施形態と同じであるが、ガス冷却器43により凝縮された水分(凝縮水32)が、凝縮水混合路54を介して前処理装置7へ流入する点で異なる。
塩化物イオン濃度が高い前処理水21に塩化物イオン濃度が低い凝縮水32を混合すると、高圧逆浸透膜9への供給水の塩化物イオン濃度が低下する。これにより、消費エネルギーも減少し、運用コスト低減を図ることができる。
5.図14に第5変形例に係る排ガス処理システムの構成を示す。ガス冷却器43により凝縮された水分(凝縮水32)を、凝縮水混合路54を介して前処理装置7前段において海水20と混合してもよい。
6 取水ポンプ
7 前処理装置
8 高圧ポンプ
9 高圧逆浸透膜
10 電気集塵機
11 ガス冷却器
12 吸収塔
13 煙突
14 低圧逆浸透膜
15 石膏脱水機
16 石灰石スラリ供給装置
17 低圧ポンプ
18 補給水タンク
20 海水
21 前処理水
22 濃縮水
23 透過水
24 濃縮水
25 透過水
26 淡水
28 石膏
29 脱水ろ液
30 脱硫排水
31 補給水
32 凝縮水
36 石灰石スラリ
37 補充石灰石スラリ
40 バイパス弁
41 排水弁
42 温度調節弁
43 ガス冷却器(第2ガス冷却器)
46 温度センサ
47 排ガス状態センサ
48 塩化物イオン濃度センサ
49 入力端末
50 コントローラ
51 補給水供給路
52 ポンプ
53 補給水供給路(第2補給水供給路)
54 凝縮水混合路
Claims (7)
- ボイラの排ガス(1)中に含まれる硫黄酸化物を除去する湿式脱硫装置(12)と、
海水(20)を昇圧するポンプ(8,17)と、このポンプから送水される海水を透過水(23,25)と非透過水(22,24)に分離する膜処理装置(9,14)とを有する造水装置と、
前記透過水の少なくとも一部を補給水(31)として前記脱硫装置に供給する補給水供給路(18,51)と
を備えた排ガス処理システムにおいて、
さらに、前記脱硫装置に流入する排ガスを前記造水装置で用いる海水により冷却する排ガス冷却機能(11a)と、排ガスを冷却する際に、この排ガスの熱により海水を加温する海水加温機能(11b)とを有するガス冷却器(11)
を備えることを特徴とする排ガス処理システム。 - 更に、前記海水加温機能により加温された海水の水温を調節して、水温調節された海水を前記ポンプに供給する水温調節手段(6,40,41,43,50)
を備えることを特徴とする請求項1に記載の排ガス処理システム。 - 前記造水装置は、海水を昇圧する第1ポンプ(8)と、この第1ポンプから送水される海水を透過水(23)と非透過水(22)に分離する第1膜処理装置(9)と、この1段目透過水の一部を昇圧する第2ポンプ(17)と、この第2ポンプから送水される1段目透過水を透過水(25)と非透過水(24)に分離する第2膜処理装置(14)とを有し、
前記補給水供給路(18,51)は、1段目透過水(23)と2段目非透過水(24)を前記脱硫装置(12)に供給する
ことを特徴とする請求項1に記載の排ガス処理システム。 - 前記ガス冷却器(11)の排ガス冷却機能(11a)は、前記1段目透過水(23)により排ガスを冷却する
ことを特徴とする請求項3に記載の排ガス処理システム。 - 更に、前記湿式脱硫装置(12)より排出される排ガスを前記造水装置で用いる海水(21)により冷却し、排ガス中に含まれる水分を凝縮除去する第2ガス冷却器(43)と、
前記第2ガス冷却器による凝縮水(32)の少なくとも一部を補給水として前記脱硫装置に供給する第2補給水供給路(53)と
を備えることを特徴とする請求項1に記載の排ガス処理システム。 - 更に、前記湿式脱硫装置(12)より排出される排ガスを前記造水装置で用いる海水(21)により冷却し、排ガス中に含まれる水分を凝縮除去する第2ガス冷却器(43)と、
前記第2ガス冷却器による凝縮水(32)の少なくとも一部を前記膜処理装置(9,14)に送水される海水(20,21)と混合する凝縮水混合路(54)と
を備えることを特徴とする請求項1に記載の排ガス処理システム。 - 海水(20,21)を昇圧し、この海水を膜処理装置(9,14)により透過水と非透過水に分離する造水ステップと、
造水ステップで得られた透過水(23,25)の少なくとも一部を補給水(31)として湿式脱硫装置(12)に供給する補給水供給ステップと、
補給水供給ステップで水分を補給しながら、石灰石スラリ(36)を噴霧する湿式脱硫装置(12)により、ボイラの排ガス(1)中に含まれる硫黄酸化物を除去する排ガス脱硫ステップと
を備えた排ガス処理方法において、
前記排ガス脱硫ステップで前記脱硫装置に流入する排ガス(1)を、前記造水ステップで用いる海水(20,21)により冷却するとともに、排ガスを冷却する際に、この排ガス(1)の熱により海水(20,21)を加温する排ガス冷却・海水加温ステップ
を備えることを特徴とする排ガス処理方法。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2011364139A AU2011364139B2 (en) | 2011-03-30 | 2011-03-30 | Exhaust gas treatment system and exhaust gas treatment method |
PCT/JP2011/058099 WO2012131951A1 (ja) | 2011-03-30 | 2011-03-30 | 排ガス処理システムおよび排ガス処理方法 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2011/058099 WO2012131951A1 (ja) | 2011-03-30 | 2011-03-30 | 排ガス処理システムおよび排ガス処理方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012131951A1 true WO2012131951A1 (ja) | 2012-10-04 |
Family
ID=46929774
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/058099 WO2012131951A1 (ja) | 2011-03-30 | 2011-03-30 | 排ガス処理システムおよび排ガス処理方法 |
Country Status (2)
Country | Link |
---|---|
AU (1) | AU2011364139B2 (ja) |
WO (1) | WO2012131951A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110272082A (zh) * | 2019-07-24 | 2019-09-24 | 北京新世翼节能环保科技股份有限公司 | 脱硫废水蒸发结晶耦合烟气再热一体化系统 |
CN111777091A (zh) * | 2020-07-29 | 2020-10-16 | 山东民基新材料科技有限公司 | 基于特戊酸副产废酸和环氧氯丙烷废水制备硫酸钙和氯化氢的方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6230530A (ja) * | 1985-07-31 | 1987-02-09 | Kawasaki Heavy Ind Ltd | 電気透析を伴う湿式排煙処理方法およびその装置 |
JPH11197450A (ja) * | 1998-01-20 | 1999-07-27 | Babcock Hitachi Kk | 湿式脱硫装置とその運転方法 |
JP2005144301A (ja) * | 2003-11-13 | 2005-06-09 | Mitsubishi Heavy Ind Ltd | 脱塩処理装置および脱塩処理方法 |
-
2011
- 2011-03-30 AU AU2011364139A patent/AU2011364139B2/en not_active Ceased
- 2011-03-30 WO PCT/JP2011/058099 patent/WO2012131951A1/ja active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6230530A (ja) * | 1985-07-31 | 1987-02-09 | Kawasaki Heavy Ind Ltd | 電気透析を伴う湿式排煙処理方法およびその装置 |
JPH11197450A (ja) * | 1998-01-20 | 1999-07-27 | Babcock Hitachi Kk | 湿式脱硫装置とその運転方法 |
JP2005144301A (ja) * | 2003-11-13 | 2005-06-09 | Mitsubishi Heavy Ind Ltd | 脱塩処理装置および脱塩処理方法 |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110272082A (zh) * | 2019-07-24 | 2019-09-24 | 北京新世翼节能环保科技股份有限公司 | 脱硫废水蒸发结晶耦合烟气再热一体化系统 |
CN110272082B (zh) * | 2019-07-24 | 2023-12-19 | 北京新世翼节能环保科技股份有限公司 | 脱硫废水蒸发结晶耦合烟气再热一体化系统 |
CN111777091A (zh) * | 2020-07-29 | 2020-10-16 | 山东民基新材料科技有限公司 | 基于特戊酸副产废酸和环氧氯丙烷废水制备硫酸钙和氯化氢的方法 |
CN111777091B (zh) * | 2020-07-29 | 2022-11-08 | 山东民基新材料科技有限公司 | 基于特戊酸副产废酸和环氧氯丙烷废水制备硫酸钙和氯化氢的方法 |
Also Published As
Publication number | Publication date |
---|---|
AU2011364139B2 (en) | 2014-04-24 |
AU2011364139A1 (en) | 2013-02-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Nassrullah et al. | Energy for desalination: A state-of-the-art review | |
AU2014227218B2 (en) | CO2 recovery system and CO2 recovery method | |
CN101417826B (zh) | 一种处理脱硫废水的方法及系统 | |
US9474998B2 (en) | Combined carbon dioxide capture and desalination device | |
JP4022555B2 (ja) | バイオガスの精製方法及びバイオガス精製設備 | |
WO2018045707A1 (zh) | 一种利用电厂余热的水处理装置及方法 | |
JP5082661B2 (ja) | 水処理システム | |
US20120067046A1 (en) | Power plant with co2 capture and water treatment plant | |
JPS5916515B2 (ja) | 火力発電所の冷却水循環系および蒸気循環系用添加水ならびに生成廃水の処理方法 | |
JP4688842B2 (ja) | 排水処理方法 | |
RU2540613C2 (ru) | Система очистки технологического газа | |
WO2012008013A1 (ja) | 濃縮プラント、濃縮造水発電プラント、濃縮方法及び濃縮造水発電プラントの運転方法 | |
WO2013121547A1 (ja) | 海水淡水化システム | |
KR20150038100A (ko) | 원유 및 천연 가스 공정 시설에서 생산수처리 공정 | |
EA022491B1 (ru) | Система и способ термической дистилляции | |
KR102095276B1 (ko) | 증기 발전 설비의 공정 폐수 회수 방법 | |
CN115893559A (zh) | 一种脱硫废水零排放系统及脱硫废水零排放工艺 | |
Han et al. | Waste heat utilization from boiler exhaust gases for zero liquid discharge of desulphurization wastewater in coal-fired power plants: Thermodynamic and economic analysis | |
WO2012131951A1 (ja) | 排ガス処理システムおよび排ガス処理方法 | |
WO2017066534A1 (en) | Hybrid cooling and desalination system | |
KR100733696B1 (ko) | 해수담수화장치 | |
EP3517508A1 (en) | Zero liquid discharge treatment process for recovering water from a contaminated liquid effluent for its subsequent reuse | |
CN208440312U (zh) | 一种脱硫废水的处理系统 | |
TWI830883B (zh) | 純水製造裝置以及純水製造方法 | |
EP2611735B1 (en) | System and method for the desalination of sea water |
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: 11862109 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2011364139 Country of ref document: AU Date of ref document: 20110330 Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 11862109 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: JP |