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
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/46—Removing components of defined structure
  • B01D53/48—Sulfur compounds
  • B01D53/50—Sulfur oxides
• • 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
  • B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
  • B01D53/504—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific device
• • 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
• • 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
  • B01D53/1481—Removing sulfur dioxide or sulfur trioxide
• • 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
• • 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
  • B01D53/507—Sulfur oxides by treating the gases with other liquids
• • 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
  • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
  • B01D53/77—Liquid phase processes
  • B01D53/78—Liquid phase processes with gas-liquid contact
• • 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
  • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
  • B01D53/86—Catalytic processes
  • B01D53/8603—Removing sulfur compounds
  • B01D53/8609—Sulfur oxides

Definitions

• the present invention relates to a ventilation device for a flue gas cleaning device, a plate aerator for the ventilation device according to the invention, a membrane for the plate aerator and a method.
• Flue gas which is produced in particular during the combustion of fossil fuels, often contains a considerable proportion of sulfur oxides, among other things. Due to their aggressiveness towards the environment, the emission of sulfur oxides should be avoided as much as possible. For this purpose, flue gas cleaning devices are used.
• Generic devices for the purification of flue gas are already known, for example in power plants, in which energy is generated from fossil fuels, in particular coal power plants, oil power plants, gas power plants or the like.
• Generic devices typically include a scrubber with scrubbing liquid nozzles that are often arranged in multiple levels, a scrubbing liquid sump in which scrubbing liquid is collected, and an absorption area that extends in a cylindrical container portion of the scrubber from the scrubbing liquid sump to the upper scrubbing liquid nozzle level. Flue gas is passed into a lower portion of the absorption area in the scrubber, flows from there substantially vertically upward and leaves the scrubber through an outlet opening provided above the scrubbing liquid nozzles.
• the washing liquid also called absorbent, contains substances which, among other things, bind or chemically convert sulfur oxides.
• the flue gas comes out of the washing Liquid nozzles exiting washing liquid in contact and is cleaned, in particular desulfurized, which is described in more detail below.
• Such a cleaning device is known for example from DE-A-100 58 548.
• the washing liquid preferably comprises substances with alkali and / or alkaline earth metal parts which react with the sulfur oxides present in the flue gas and with the sulfur oxides produced in the scrubber.
• alkali and / or alkaline earth metal parts which react with the sulfur oxides present in the flue gas and with the sulfur oxides produced in the scrubber.
• calcium oxide, calcium hydroxide, calcium bicarbonate, calcium carbonate or the like is used.
• alkaline substances, in particular hydrogen carbonate are already present in the washing liquid.
• the alkaline substances react when using seawater as washing liquid with the sulfur oxides present in the flue gas substantially to sulfates, which are then dissolved in seawater.
• the flue gas is thus purified of the unwanted sulfur oxides and exits the purifier.
• the washing liquid together with the sulfate particles suspended in it, enters the washing liquid sump and is collected there.
• Calcium sulphate is the substance that underlies the gypsum. Thus, this is a desirable by-product of the flue gas cleaning process that is recovered from the scrubbing liquid collected in the scrubbing liquid sump.
• the calcium sulfate particles are removed together with the scrubbing liquid from the scrubbing liquid sump and this removed in a subsequent process.
• the calcium sulfate can then be further processed into various materials, in particular to construction materials.
• a problem with the recovery of calcium sulfate is that in the reaction of the washing liquid with the flue gas not only calcium sulfate, but also undesirable by-products such as sulfites, especially calcium sulfite, which contaminate the calcium sulfate and thus reduce the quality of the by-product.
• undesirable by-products such as sulfites, especially calcium sulfite, which contaminate the calcium sulfate and thus reduce the quality of the by-product.
• seawater the washing liquid
• sulfites are formed as undesirable by-products in accordance with the dissolved alkaline substances.
• the flue gas cleaning device according to DE 295 17 698 the sulfite formed is oxidized in the absorber sump. The sulfur dioxide separation takes place here not by addition of alkaline earths, but by bicarbonate. Also in this process, sulfite is formed.
• US Pat. No. 4,539,184 proposes oxygen in the form of air or liquid in at least one region of the scrubbing liquid sump to introduce the same to oxidize there existing calcium sulfites to calcium sulfate.
• CA-A-2 135 430 also describes a flue gas cleaning device with an oxidation device provided in the scrubbing liquid sump in the form of a horizontally arranged grid consisting of oxygen supply lines with corresponding openings, through which oxygen can be introduced into the scrubbing liquid collected in the scrubbing liquid sump.
• the horizontal grid is positioned in the washing liquid sump so that it is divided into two areas.
• the scrubber tower usually has at least one lower inlet for the unpurified flue gas, below the flue gas inlet a sump for an absorbent, above the flue gas inlet a unit with which the absorbent is sprayed into the incoming flue gas, and one arranged in the upper region of the scrubber tower Outlet for the purified flue gas.
• the absorbent is usually liquid and contains, for example, calcium carbonate, which reacts with the oxides of sulfur to form calcium sulfite and calcium sulfate (gypsum). Methods are also used which use seawater as the absorbent.
• Seawater contains in addition to alkaline substances in particular hydrogen carbonate, which also react with the sulfur oxides.
• gypsum accumulates, which does not have to be disposed of with sufficient purity, but can be supplied to a further utilization, for example in the building materials industry.
• the sulfite content is as low as possible relative to the sulfate content.
• oxygen is supplied to the spent absorbent, so that the highest possible proportion of sulfites is further oxidized to sulfates.
• the invention proposes as a solution to provide a generic ventilation device for a flue gas cleaning device in a ventilation area with at least one plate aerator, which is immersed in a fluid absorbent arranged in the ventilation area.
• the absorbent is the substantially spent fluid absorbent derived from the absorption reaction, optionally mixed with fresh absorbent.
• the plate aerator allows the oxidant, for example air, to be supplied to the absorbent over an enlarged area. As a result, an acceleration of the sulfate formation and a higher efficiency can be achieved.
• sulphite test values of less than about 1.5% by weight, especially less than about 1.0% by weight, can be achieved.
• the goal is complete oxidation.
• the returning seawater then has a quality that complies with current environmental regulations.
• the venting area is part of the venting device in which the absorbent can be contacted with the oxidant.
• the ventilation device may be formed, for example, as part of the sump, as a sump as a whole, as a separate vessel or basin or the like. In the latter case, the basin or the vessel is in fluid communication with the bottom of the scrubber tower.
• the plate aerator may, for example, be formed by plates having a cavity in fluid communication with an oxidant source.
• the surface of a plate of the plate aerator is provided with at least one opening through which the oxidant can enter the absorbent.
• the oxidant is often gaseous and is injected through the opening in the absorbent.
• the plate aerator may have a plurality of plates of this kind, which may be stacked or the like, for example.
• the plates are fluidically connected to a common oxidant source.
• seawater is used as the absorbent.
• costs can be further reduced.
• this is advantageous for systems that are installed in the coastal area, so where seawater can be provided inexpensively.
• the ventilation area is formed by a ventilation basin communicating fluidly with a sump of the flue gas purification device.
• a ventilation basin communicating fluidly with a sump of the flue gas purification device.
• both devices can be optimally formed independently of one another for their intended purpose.
• the ventilation device does not need to be adapted in terms of its dimensions to the dimensions of the scrubber tower, whose dimensions are fixed by its intended operation as a scrubber tower.
• the optimal design possibility of the aeration basin the efficiency can be further increased.
• the ventilation device can be optimized according to fluidic aspects to reduce energy consumption for flow generation.
• the connection between sump and aeration basin can be formed for example by a pipeline or the like. However, it may also be formed a common pool, which forms the sump and the aeration basin at the same time, wherein the ventilation area of the aeration basin is arranged outside of the sump area. Both can also be fluidically connected through an opening.
• the plate aerators extend substantially over the entire ventilation area. This makes it possible to design the aeration basin as small as possible in terms of its dimensions. Costs can be saved.
• the ventilation device has a circulation unit for the absorbent. With the circulation unit, an additional increase in the effect of the ventilation device can be achieved. By circulating the absorbent, moreover, an increased amount of oxidant can be introduced into the absorbent, so that an acceleration of the reaction can be achieved.
• the plate aerator and the circulation unit are formed in one piece. In this way, separate units can be saved. For example, circulating pumps or the like may be provided on the plates. The procedure can be further optimized.
• a circulation can also be generated by a fluidic arrangement of the plate aerators, flow obstacles / installations and / or gas injection.
• the plate aerator is arranged on a grid.
• the arrangement on a grid makes it easy to arrange the plate aerators in the aeration basin.
• the grid holds the plate aerators in their intended position so that they can perform their intended function optimally.
• the grid may be formed by conduits through which the oxidant may be supplied to the individual plates of the plate aerator. In this way, at the same time a simple and convenient feeding of the plates of Plattenbelfurfur achieved with the oxidant.
• the invention also proposes a plate aerator for the ventilating device according to the invention, wherein the plate aerator is substantially plate-shaped.
• the dish shape permits the production of as large a surface as possible, which can be brought into contact with the absorbent.
• the plate shape is ideal for the formation of a stacked structure or the like, so that a compact design can be achieved at the same time high contact area with the absorbent.
• the plate aerator is formed substantially oval. Due to the oval shape can be achieved taking into account aerodynamic aspects that the aeration basin can be reduced in terms of its dimensions such as height, width or length. Costs can be further saved. Alternative shapes such as round, square, etc. are within the scope of the invention.
• the plate aerator has a perforated membrane.
• the perforated membrane allows for a variety of openings, pores or slots through which the oxidant can be introduced into the absorbent.
• the membrane may for example be formed from a plastic or the like, in which corresponding openings are provided. A high number of openings can be achieved.
• the configuration in the form of a membrane allows the openings to be optimally matched in terms of their diameter to the intended operation. The efficiency of the ventilation device can be further improved overall.
• the membrane is exchangeable. This is particularly advantageous when single or a plurality of pores are added or there is damage to the membrane. In this way it can be achieved that not the entire plate aerator must be replaced, but only the membrane on Plattenbellusterer. Costs can be further saved.
• the invention also proposes a membrane for a plate aerator according to the invention which has pores for a fluid oxidant.
• the pores are selected in number and diameter such that optimum effect of the oxidant in the absorbent can be achieved.
• a large part of the existing sulfite content should be further oxidized to sulfate.
• the membrane has one to 10 pores per cm 2 .
• the number of pores also depends on the diameter of the pores, which in turn should be adapted to the viscosity of the oxidant and the fluid. The provision of pores allows the membrane to be industrially manufactured while meeting high quality requirements.
• the pores on average have a diameter of about 0.1 to 1.5 mm, preferably about 0.25 to 0.9 mm, particularly preferably about 0.4 to 0.8 mm. It has been found that this pore size is suitable for optimizing the feed of the oxidant into the absorber.
• the membrane has at least one slot instead of pores or in addition to pores.
• the slot for example, gas bubbles can be generated in the absorbent, which at the same time cause a circulation in a predeterminable manner.
• This embodiment is particularly advantageous in combination with pores, so that, for example, small, very finely distributed gas bubbles are produced through the pores, which due to their size experience only a very slight buoyancy in the absorbent, whereas the gas bubbles generated by a slot cause a high buoyancy and due to their ascension cause the Absorbens in a desired direction.
• the effect of the ventilation device can be further improved.
• the membrane is formed of EPDM (ethylene-propylene-diene-monomeric membrane).
• EPDM ethylene-propylene-diene-monomeric membrane.
• a membrane made of this material is characterized by a high degree of robustness, so that maintenance can be reduced.
• the operation of the ventilation device can be further optimized. Also silicone or other suitable plastics can be used.
• the invention further proposes a method for aerating an absorbent in a ventilation device according to the invention, wherein the liquid absorbent arranged in a ventilation region of the aeration device is supplied with a gaseous oxidant by means of a plate aerator immersed in the absorbent, wherein in the absorbent the oxidant containing gas bubbles whose average diameter is substantially less than about 1, 5 mm, preferably less than about 1, 0 mm, in particular less than about 0.7 mm. is. It has been found that the gas bubbles remain in contact with the absorber in comparison with known ventilating devices. remain because they are only exposed to low buoyancy in the absorber because of their size. By increasing the number of gas bubbles, with the same amount of oxidant, a surface enlargement of the oxidant can be achieved with the absorber so that a reaction in the desired sense can be accelerated and achieved with high efficiency.
• gas bubbles are generated by means of a slit of the plate aerator, which effect a circulation of the absorbent.
• a flow is achieved in the absorbent, wherein the flow preferably forms such that the largest possible proportion of the absorbent can be brought into contact with the oxidant.
• the part of the absorbent can be achieved, which is not directly in contact with the plate aerator.
• the oxidant used is essentially oxygen, air or an oxygen-containing gas or gas mixture which releases oxygen when introduced into the absorbent.
• FIG. 1 is a perspective view in partial section of a flue gas cleaning device with a ventilation device according to the invention and a scrubber tower,
• FIG. 3 is a plan view of a ventilation basin of the invention
• Ventilation device with plate fans arranged on a grille and
• Fig. 4 shows an enlarged view of a grid section with Plattenbelforern according to the invention.
• Fig. 1 is a perspective partially cutaway view of a flue gas cleaning device 10 is shown having a scrubber tower 20 and a ventilation device 12. For the sake of clarity, the feed area of the flue gas to be cleaned and the discharge area are not shown.
• the scrubber tower 20 has in its lower region a sump 18 in which an absorbent, in the present case seawater, is arranged. Other substances may be added to the seawater to improve the operation of the flue gas cleaning device 10.
• pumps 28 are arranged, which lead via lines 24, the absorbent to a Eindüs Scheme 26 within the scrubber tower 20.
• FIG. 2 shows the flue gas cleaning device 10 according to FIG. 1 in a schematic block diagram.
• the sump 18 is in fluid communication with a ventilation basin 14 of a ventilation device 12 via an opening 32 in connection.
• a grid 34 is immersed immersed with Plattenbelforern 16 in the absorbent.
• the aeration basin 14 has a width of about 20 m and a length of about 70 m (FIG. 3).
• the individual Plattenbelpresenter 16 are arranged and are supplied via this with air as oxidant.
• each grid 34 has a length of about 9 m, with plate aerators 16 being stacked on each grid 34 (FIG. 4).
• Each plate aerator 16 is substantially plate-shaped and oval.
• the large half-axis of the oval extension is aligned approximately parallel to the liquid surface of the absorbent.
• the dimension of the semi-major axis is about 0.7 m and the small semi-axis about 0.2 m.
• the thickness of the plate aerator 16 is about 0.02 m.
• the plate aerators 16 are arranged at a distance of about 0.1 m. From a Oxidans provoke not shown is supplied via lines 30 to the grid 34 air as oxidant. This flows via the grids 34 into the plate aerators 16 and exits there through a membrane not shown in the absorber. As a result, a good supply of the absorbent with oxidant is achieved.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Environmental & Geological Engineering (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)
• Treating Waste Gases (AREA)
• Gas Separation By Absorption (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Related Child Applications (1)

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Citations (5)

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• 2006
  • 2006-12-23 ES ES09008295T patent/ES2400262T3/es active Active
  • 2006-12-23 PT PT90082959T patent/PT2100657E/pt unknown
  • 2006-12-23 KR KR1020137020277A patent/KR101398118B1/ko not_active Expired - Fee Related
  • 2006-12-23 WO PCT/EP2006/012527 patent/WO2008077430A1/de not_active Ceased
  • 2006-12-23 KR KR1020127006840A patent/KR20120061888A/ko not_active Ceased
  • 2006-12-23 EP EP06841162A patent/EP1960088A1/de not_active Withdrawn
  • 2006-12-23 EP EP09008295A patent/EP2100657B1/de not_active Not-in-force
  • 2006-12-23 BR BRPI0622233-1A patent/BRPI0622233A2/pt not_active Application Discontinuation
  • 2006-12-23 KR KR1020097011425A patent/KR20090087029A/ko not_active Abandoned
  • 2006-12-23 CN CNA2006800011974A patent/CN101300061A/zh active Pending
• 2007
  • 2007-07-12 JP JP2007183026A patent/JP2008155195A/ja active Pending

Patent Citations (5)

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