JP3818963B2 - Combustion exhaust gas treatment method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion exhaust gas treatment method and apparatus for removing harmful components in combustion exhaust gas.
[0002]
[Prior art]
In exhaust gas discharged from a dust incinerator, a sintering machine, or the like, in addition to dust, components that cause air pollution such as sulfur oxide, dioxin, and nitrogen oxide are included. For this reason, when exhaust gas is discharged into the atmosphere, it is necessary to remove these harmful components together with dust.
For example, in the treatment of exhaust gas containing dust discharged from a blast furnace, a granulated product produced by firing iron oxide and coke powder is provided as a filter medium in the dust collector, and the dust in the exhaust gas is separated and removed by this filter medium. It is discharged into the atmosphere. And the fine powder which generate | occur | produced from the isolate | separated dust and granulated material is collect | recovered, and it reuses as a raw material (for example, refer patent document 1). In the treatment of exhaust gas containing sulfur dioxide and ammonia, the exhaust gas is fed to the lower part of the moving bed type adsorption tower and brought into countercurrent contact with the activated carbon to adsorb sulfur dioxide by dilute sulfuric acid and ammonia by ammonium sulfate. And then discharged into the atmosphere. And this activated carbon is processed by making it react with quicklime (for example, refer patent document 2). Further, in the treatment of dioxins in the exhaust gas, the dioxins are decomposed by irradiating the inert gas with a laser beam having an optimum wavelength (see, for example, Patent Document 3), and activated alumina particles or activated bauxite particles are adsorbed. It is used to adsorb and remove dioxins in exhaust gas (for example, see Patent Document 4).
[0003]
[Patent Document 1]
JP 55-119409 A
[Patent Document 2]
JP-A-56-108513
[Patent Document 3]
JP-A-8-103623
[Patent Document 4]
JP 2001-46838 A
[0004]
[Problems to be solved by the invention]
However, in the invention described in Patent Document 1, since a granulated product is produced from iron oxide and coke powder and fired to produce a filter medium, the amount of pores formed in the granulated product is small, and the pores The size is big. For this reason, it is possible to remove large particles such as dust, but it cannot adsorb harmful components such as dioxins and nitrogen oxides in the exhaust gas, and remove harmful components that cause air pollution from the exhaust gas. It is not possible. In the invention described in Patent Document 2, desulfurization treatment and denitration treatment of exhaust gas are possible, but the removal efficiency is low, and further, it is necessary to perform secondary treatment of activated carbon that adsorbs harmful components. It is a time-consuming method. Further, when dioxins are present, it is difficult to adsorb and decompose dioxins by this method, and the exhaust gas treated by this method cannot be released into the atmosphere. The invention described in Patent Document 3 has a problem that the processing cost becomes very high, and dioxin synthesis occurs again depending on the processing conditions after decomposing dioxin. In the invention described in Patent Document 4, there are problems that the adsorption efficiency of dioxin is low and the life of the catalyst is short. Furthermore, since the catalyst is expensive, there arises a problem that the processing cost of the exhaust gas increases.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a combustion exhaust gas treatment method and apparatus capable of efficiently removing harmful components in exhaust gas at low cost.
[0005]
[Means for Solving the Problems]
A method for treating flue gas according to the present invention that meets the above-mentioned object is a flue gas treatment method for adsorbing and removing flue gas exhausted from a heating facility and containing harmful components through an adsorbent,
The adsorbent isWhile being pulverized to 1 to 10 μm and flowing for 10 to 1800 seconds at a temperature of 300 ° C. or more and less than 550 ° C.Mainly composed of limonite that has been heated and made porousAnd granulated, and further, the temperature of the combustion exhaust gas is set to 300 to 400 ° C. to remove dioxins in the combustion exhaust gas.The
[0006]
Limonite (also referred to as limonite) is iron that has eluted from the crater lake of the volcano as a hydrous oxide by chemical or biological action, and has become dry soil due to the rise of the crater lake. Limonite contains various minerals and organic matter, but its main component is characterized by containing 20 to 60% by mass of hydrous iron oxide in terms of iron and 1 to 10% by mass of organic matter in terms of carbon. . Here, the hydrous iron oxide is the structural formula FeOOH (or FeOOH).₂ O_Three ・ H₂ O).
The heat treatment is a treatment for desorbing bound water from limonite, and fine pores are formed at locations where bound water is desorbed, so that limonite becomes porous. For this reason, it is considered that when flue gas is passed through heat-treated limonite, ammonia, sulfur oxides, nitrogen oxides, and dioxins in the flue gas are captured and immobilized in the micropores formed in limonite. It is done. Here, the heat treatment of limonite is preferably performed by applying heat from the outside and heating the limonite uniformly while the limonite is put in a treatment vessel and fluidized.
[0007]
In the vicinity of the fine pores formed after the bound water is desorbed, an incomplete region is generated in the crystal structure of iron and oxygen, and some oxygen is considered to be active sites. FIG. 3 shows that activated carbon and heat-treated limonite are kept at 150 to 300 ° C., and chlorobenzene, which is an example of an organic chlorine compound, is passed through from the carbon dioxide content in the discharged gas to carbon dioxide of chlorobenzene. It shows the result of investigating the conversion rate. Even if chlorobenzene is passed through activated carbon, chlorobenzene is not converted into carbon dioxide. However, when chlorobenzene is passed through limonite, it is recognized that chlorobenzene is converted into carbon dioxide when the reaction temperature exceeds 150 ° C. This is thought to be because chlorobenzene was trapped in the micropores, and chlorobenzene was decomposed by the active site oxygen, and the carbon in chlorobenzene was oxidized and converted to carbon dioxide. Therefore, it is considered that when dioxin is captured in the active site-converted portion, the carbon constituting the dioxin is oxidized and the dioxin is decomposed.
[0008]
Heat treatment at a temperature of less than 300 ° C. is not preferable because desorption of bound water is small, resulting in a small amount of fine pores. Further, when the temperature is 550 ° C. or higher, the limonite structure is changed, and the formed fine pores are collapsed to increase the pores.
[0009]
The limonite has pores with a pore diameter of 2 nm or less, and its specific surface area is 20 m.²/ G or more is preferable.
In order to adsorb low-concentration organochlorine compounds, such as dioxins in combustion exhaust gas, it is necessary that fine pores having pore diameters several times the size of adsorbed molecules exist. When the pore size of the fine pores is smaller than the adsorbed molecules, the molecules cannot be adsorbed in the pores, and when the pore size is large, the adsorptive power decreases. The size of 2,3,7,8-T4CDD, which is the most toxic of dioxins, is about 1.8 nm in length, about 1.0 nm in width, and about 0.3 nm in thickness. As a result, fine pores of 1 nm or more and 2 nm or less are the optimum size. The specific surface area is also 20m²If it is less than / g, the area of the wall surface of the fine pores that capture dioxins becomes small, and the amount of dioxins captured and adsorbed decreases, which is not preferable. Also, the specific surface area is 500m²Even if the amount exceeds / g, there will be no significant increase in the amount captured or adsorbed.²/ G or less, and the specific surface area is 50 m.²/ M or more 250m²More stable adsorption / decomposition can be performed by using a material having a viscosity of not more than / g.
[0010]
In the method for treating combustion exhaust gas according to the present invention, the heating facility may be any one of a dust incinerator and a sintering machine.
In particular, in urban dust incinerators, a wide variety of dust is incinerated. Therefore, combustion exhaust gas contains harmful components such as ammonia, nitrogen oxides, sulfur oxides, and dioxins. Further, the combustion exhaust gas discharged from the sintering machine at the ironworks contains harmful components such as sulfur oxides, dioxins, and nitrogen oxides caused by the iron ore and limestone used. Accordingly, it is possible to discharge the combustion exhaust gas purified by removing harmful components from the combustion exhaust gas discharged from the dust incinerator and the sintering machine to the atmosphere.
[0011]
Combustion exhaust gas treatment apparatus according to the present invention that meets the above-mentioned object,A flue gas treatment device that removes harmful components including dioquine from flue gas discharged from a heating facility,
SaidIt is provided in the middle of the flue gas flow path and has a cross-sectional area larger than the flue gas passage cross-sectional area of the flow path.The temperature of the flue gas flowing in is 300 to 400 ° C.A combustion exhaust gas treatment chamber;
An adsorption layer provided in the combustion exhaust gas treatment chamber,
The adsorption layer isWhile being pulverized to 1 to 10 μm and flowing for 10 to 1800 seconds at a temperature of 300 ° C. or more and less than 550 ° C.Mainly composed of limonite that has been heated and made porousAnd granulatedIt has an adsorbent and a holding member for holding the adsorbent.
By providing a combustion exhaust gas treatment chamber having a cross-sectional area larger than the combustion exhaust gas passage cross-sectional area of the flow path in the middle of the flow path of the combustion exhaust gas, the flow rate of the combustion exhaust gas can be reduced. In addition, the combustion exhaust gas and the adsorbent are sufficiently brought into contact with each other by providing an adsorption layer in the combustion exhaust gas treatment chamber that is configured by holding the adsorbent mainly composed of limonite that has been heated and made porous. Can be made. As a result, harmful components in the combustion exhaust gas are captured by the fine pores formed in the limonite constituting the adsorbent, and can be removed from the combustion exhaust gas by being adsorbed on the wall surfaces of the fine pores.
[0012]
In the combustion exhaust gas treatment apparatus according to the present invention, the holding member may be a heat-resistant net.
By holding the adsorbent on a heat-resistant mesh (for example, a stainless steel mesh) and laminating this mesh against the flue gas flow, combustion occurs when the flue gas passes through the flue gas treatment chamber. The surface area of the adsorbent in contact with the exhaust gas flow can be kept large.
[0013]
In the combustion exhaust gas processing apparatus according to the present invention, the adsorption layer is obtained by pulverizing and heating the limonite.In the range of 1 to 3000 μmIt can be granulated and sprayed onto the net.
Limonite is pulverized to 1 to 10 μm and heat-treated, and the resulting porous limonite is granulated in the range of 1 to 3000 μm to form a heat-resistant net (for example, a pore diameter of 3 to 6 mm, a pore interval of 0.1 mm). The adsorbing layer can be formed by spraying a dust collecting net made of several 75 to 2.25 mm stainless steel. As a result, the combustion exhaust gas can be sufficiently brought into contact with the adsorption layer. Here, when the limonite is less than 1 μm, limonite is likely to be scattered, which is not preferable. Moreover, when limonite exceeds 10 μm, the interior of limonite is not evenly heated, and the amount of fine pores is reduced and the specific surface area is lowered, which is not preferable. Furthermore, when granulating limonite, if the particle size of the granulated product exceeds 3000 μm, dropout after spraying becomes remarkable, which is not preferable.
[0014]
In the combustion exhaust gas treatment apparatus according to the present invention, the holding member may be a heat-resistant container having air permeability.
When the flue gas passes through the flue gas treatment chamber by placing the adsorbent in a heat-resistant container (for example, a stainless steel container) with air permeability and facing the flue gas flow The surface area of the adsorbent in contact with the flow of the combustion exhaust gas can be kept large.
[0015]
In the combustion exhaust gas processing apparatus according to the present invention, the adsorption layer is obtained by pulverizing and heating the limonite.In the range of 1-50mmIt can be granulated and filled into the container.
Limonite is pulverized to 1 to 10 μm and heat-treated, and the resulting porous limonite is formed into a granulated product having a particle size of 50 mm or less, preferably about 20 mm, and has a breathability in a heat-resistant container. When the combustion exhaust gas passes through the combustion exhaust gas treatment chamber, the surface area of the adsorbent contacting the combustion exhaust gas flow can be kept large. In addition, if the limonite is not granulated, the ventilation resistance of the combustion exhaust gas passing through the adsorption layer is undesirably increased. Moreover, when limonite is made larger than 50 mm, the contact area with combustion exhaust gas will become small and is not preferable.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
FIG. 1 is an explanatory diagram of a combustion exhaust gas treatment apparatus according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram of a combustion exhaust gas treatment apparatus according to the second embodiment of the present invention. .
As shown in FIG. 1, a combustion exhaust gas treatment apparatus 10 according to a first embodiment of the present invention includes a cooler 12 that cools combustion exhaust gas discharged from a dust incinerator 11 that is an example of a heating facility, A combustion exhaust gas treatment chamber 13 that adsorbs and removes harmful components in the cooled combustion exhaust gas by heat treatment using limonite, a dust collector 14 that removes dust from the combustion exhaust gas from which harmful components have been removed, and combustion from which dust has been removed. A chimney 15 that discharges exhaust gas into the atmosphere and a part of a flow path that passes the combustion exhaust gas generated from the dust incinerator 11 to the chimney 15 through the cooler 12, the combustion exhaust gas treatment chamber 13, and the dust collector 14 are configured. Piping (hereinafter also referred to as flow paths) 16 to 19. Hereinafter, these will be described in detail.
[0017]
First, the combustion exhaust gas treatment chamber 13 for removing harmful components in the combustion exhaust gas will be described. The flue gas treatment chamber 13 includes a flue gas treatment chamber main body 20 having a cross-sectional area larger than the cross-sectional area of the pipe 17 for supplying the flue gas cooled from the cooler 12 to the flue gas treatment chamber 13, and a flue gas treatment chamber main body 20 Each of the adsorption layers 23 includes an adsorbent 21 mainly composed of limonite that has been heated and made porous, and a holding member that holds the adsorbent 21. An example is a stainless steel dust collection net 22. Time required for passing through the adsorption layer 23 by reducing the flow velocity of the flue gas flowing into the flue gas treatment chamber main body 20 by making the cross-sectional area of the flue gas treatment chamber main body 20 larger than the cross-sectional area of the pipe 17. Can be lengthened. As a result, harmful components in the combustion exhaust gas can be adsorbed efficiently.
Here, as the dust collection net | network 22, a thing with a hole diameter of 3-6 mm and a hole space | interval of 0.75-2.25 mm can be used, for example. Further, the adsorbent 21 pulverizes limonite, for example, to 1 to 10 μm, puts it in a fluidized heat treatment furnace, and sets the heating temperature to 300 to 550 ° C., preferably 450 to 500 ° C. A heat treatment was carried out for 1800 seconds to produce bound water in limonite. The heat-treated limonite has a large number of fine pores having a pore diameter of 2 nm or less, and the specific surface area is 20 m.² / G or more. Further, the plurality of adsorption layers 23 are formed by laminating (for example, 10) stainless steel dust collection nets 22 having different hole formation angles of 90 degrees to form a laminated body, and the limonite subjected to heat treatment on this laminated body. A slurry prepared by adding an appropriate amount of water was sprayed using a nozzle, and limonite was deposited around the holes and in the gaps between the dust collection nets 22.
[0018]
In the dust incinerator 11, although the combustion temperature varies depending on the type of waste to be incinerated, the incineration is generally performed at a temperature of 1200 to 1300 ° C. For this reason, the temperature of the generated combustion exhaust gas is also high, and is 800 to 1000 ° C. on the outlet side of the dust incinerator 11. On the other hand, the adsorbent 21 that adsorbs and removes harmful components (for example, dioxin, sulfur oxide, nitrogen oxide, ammonia) contained in the combustion exhaust gas is heat-treated at a temperature of 300 ° C. or higher and lower than 550 ° C. Since it is limonite, when combustion exhaust gas having a temperature of 550 ° C. or higher flows, the fine pores formed in limonite by heat treatment collapse and the function of adsorbing and removing harmful components decreases. For this reason, the temperature of the combustion exhaust gas discharged from the dust incinerator 11 needs to be cooled to, for example, 300 to 400 ° C. using the cooler 12, and then flowed into the combustion exhaust gas treatment chamber 13.
Here, as the cooler 12, for example, an opposed heat exchanger that allows combustion exhaust gas to pass through to the primary side and air to pass through to the secondary side can be used. The heated air obtained on the secondary side can be used as secondary air supplied to the combustor of the dust incinerator 11. The reason why the temperature of the combustion exhaust gas after cooling is set to 300 to 400 ° C. is that decomposition of dioxin does not proceed efficiently when the temperature is less than 300 ° C. The reason why the temperature is set not to exceed 400 ° C. is to prevent the fine pores formed in limonite from gradually collapsing even when the combustion exhaust gas is supplied to the combustion exhaust gas treatment chamber 13 for a long period of time.
[0019]
When the combustion exhaust gas passes through each adsorption layer 23 provided in the combustion exhaust gas treatment chamber main body 20, a part of the dust in the combustion exhaust gas is captured by a narrow path formed in the adsorption layer 23. The remaining dust rides on the flow of the combustion exhaust gas and is discharged into the flow path 18 connected to the downstream side of the combustion exhaust gas treatment chamber body 20. For this reason, the dust collector 14 is connected to the flow path 18 to remove dust in the combustion exhaust gas. Here, as the dust collector 14, an electric dust collector or a bag filter type dust collector can be used, and an electric dust collector and a bag filter type dust collector can also be used in combination.
The combustion exhaust gas discharged from the dust collector 14 is cleaned because harmful components are adsorbed and removed by the adsorption layer 23 in the combustion exhaust gas treatment chamber 13 and the dust is separated and removed by the dust collector 14. For this reason, it can guide to the lower part of the chimney 15 with the flow path 19, and can discharge | emit it in air | atmosphere via the chimney 15.
[0020]
Next, a method of using the combustion exhaust gas treatment apparatus 10 according to the first embodiment of the present invention will be described in detail.
The combustion exhaust gas generated in the dust incinerator 11 is introduced into the cooler 12 through the flow path 16 and is exchanged with the secondary air supplied to the combustor of the dust incinerator 11 so that the temperature of the combustion exhaust gas is set to 300, for example. Cool to ~ 400 ° C.
[0021]
The combustion exhaust gas cooled by the cooler 12 passes through the flow path 17 and flows into the combustion exhaust gas treatment chamber 13. In the combustion exhaust gas treatment chamber 13, an adsorption layer 23 provided with an adsorbent 21 mainly composed of limonite held in a dust collection network 22 is provided to face the flow of combustion exhaust gas. For this reason, when combustion exhaust gas permeate | transmits the adsorption layer 23, it contacts with the limonite which is the main body of the adsorption agent 21, and the harmful | toxic component in combustion exhaust gas is capture | acquired by the fine pore formed in limonite. Here, among harmful components, sulfur oxide, nitrogen oxide, and ammonia are trapped in the fine pores and adsorbed on the wall surfaces of the fine pores. Dioxins are trapped in fine pores, and then decomposed by oxidation of carbon by oxygen active sites formed around the fine pores. In this way, harmful components in the combustion exhaust gas are adsorbed and removed by fine pores in limonite when passing through the adsorption layer 23. On the other hand, the dust in the combustion exhaust gas is partially captured by the adsorption layer 23 when passing through the adsorption layer 23, but the remaining dust remains in the combustion exhaust gas and is discharged to the flow path 18.
[0022]
Next, the combustion exhaust gas discharged into the flow path 18 is caused to flow into the dust collector 14 to remove dust in the combustion exhaust gas. Then, the combustion exhaust gas purified by removing harmful components and dust is sent to the chimney 15 through the flow path 19 and discharged into the atmosphere.
In addition, since the main component of the adsorbent 21 is iron, the used adsorbent 21 is peeled off from the dust collection net 22 and recovered and used as an iron-making raw material. The dust collection net 22 is reused as a holding member.
[0023]
The combustion exhaust gas treatment device 24 according to the second embodiment of the present invention removes harmful components in the combustion exhaust gas discharged from a sintering machine 25 (an example of a heating facility) that manufactures sintered ore to be supplied to a blast furnace. Combustion exhaust gas treatment chamber 26 for adsorbing and removing, dust collector 27 for removing dust in the combustion exhaust gas from which harmful components have been removed, chimney 28 for discharging the combustion exhaust gas from which dust has been removed to the atmosphere, and sintering the combustion exhaust gas It has piping 29-31 which constitutes a part of the channel which supplies from the machine 25 to the chimney 28 via the combustion exhaust gas treatment chamber 26 and the dust collector 27. Here, the flue gas treatment chamber 26 provided in the flue gas treatment device 24 according to the second embodiment is the flue gas treatment chamber provided in the flue gas treatment device 10 according to the first embodiment. Since the configuration can be substantially the same as 13, detailed description is omitted. The dust collector 27 is preferably an electric dust collector, for example.
[0024]
Then, the usage method of the processing apparatus 24 of the combustion exhaust gas which concerns on the 2nd Embodiment of this invention is demonstrated.
The sintered ore raw material in the raw material hopper 32 is supplied to a pallet (not shown) disposed in the sintering furnace 34 via the chute 33, and coke in the raw material is combusted while supplying air from an air supply port (not shown). And the temperature of a raw material is raised, moving a pallet gradually toward the discharge port side which is not shown in figure (in FIG. 2, moving from the left side to the right side), and a sintered ore is manufactured. The combustion exhaust gas generated at this time flows into a wind box 35 provided below the sintering furnace 34 and divided into a plurality of chambers, and then divided into a plurality of chambers provided below the window box 35. Flows into the main duct 36. Here, since sufficient oxygen still exists in the combustion exhaust gas flowing into the first low temperature side duct portion 37 provided in the main duct 36, the oxygen is supplied to the high temperature side combustion air box 38 and is used for combustion 2. Used by mixing with secondary air. Further, since the combustion exhaust gas flowing into the second low temperature side duct portion 39 has a low combustion temperature, sulfur oxides, nitrogen oxides, and dioxins are not generated. For this reason, the combustion exhaust gas in the 2nd low temperature side duct part 39 is attracted | sucked by the blower 41 via the piping 40 connected to the 2nd low temperature side duct part 39, and is discharged | emitted from the chimney 28 in air | atmosphere.
[0025]
Further, dust, sulfur oxide, nitrogen oxide, and dioxin are present in the combustion exhaust gas flowing into the intermediate temperature side duct portion 42 provided in the main duct 36. For this reason, the flue gas flows into the flue gas treatment chamber 26 through the pipe 29 and permeates the adsorption layer 23 provided with the adsorbent 21 mainly composed of limonite, and the fine particles formed in the limonite at that time. The pores capture sulfur oxides, nitrogen oxides, and dioxins. The trapped sulfur oxides and nitrogen oxides are adsorbed on the wall surfaces of the fine pores, and the dioxins are oxidized and decomposed after being adsorbed on the wall surfaces of the fine pores. A part of the dust is captured by the adsorption layer 23, but the remaining dust is contained in the combustion exhaust gas discharged from the combustion exhaust gas treatment chamber 26, so that it flows into the dust collector 27 via the pipe 30. The remaining dust is removed and discharged from the chimney 28 through the pipe 31 and the blower 41 to the atmosphere.
[0026]
Since oxygen remains in the combustion exhaust gas flowing into the first high temperature side duct portion 43 provided in the main duct 36, it is blown into the intermediate temperature side combustion air box 44 and mixed with the combustion secondary air. Is done. In addition, dust, sulfur oxide, nitrogen oxide, and dioxin are present in the combustion exhaust gas flowing into the second high temperature side duct portion 45 provided in the main duct 36. It is necessary to remove sulfur oxides, nitrogen oxides, and dioxins by flowing in, and to remove dust with the dust collector 27. However, since the temperature of the combustion exhaust gas flowing into the second high temperature side duct portion 45 is high, when it is directly supplied to the combustion exhaust gas treatment chamber 26, the fine pores formed in the limonite that is the main component of the adsorbent 21 collapse. Therefore, after the combustion exhaust gas flowing into the second high temperature side duct portion 45 is supplied to the intermediate temperature side duct portion 42 and mixed with the low temperature combustion exhaust gas flowing into the intermediate temperature side duct portion 42 to reduce the temperature, the combustion exhaust gas Supply to the processing chamber 26. The used adsorbent 21 is peeled off from the dust collection net 22 and recovered and used as a steelmaking raw material, and the dust collection net 22 is reused as a holding member.
[0027]
As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. A case where the flue gas treatment method and apparatus of the present invention are configured by combining some or all of the forms and modifications is also included in the scope of the right of the present invention. For example, a stainless steel dust collection net is used for the holding member, and an adsorbent is sprayed onto it to form an adsorption layer, but a heat-resistant container with air permeability, for example, a stainless steel basket is used. The adsorbed layer can also be constituted by filling the cocoons with, for example, limonite granulated in the range of 1 to 50 mm.
[0028]
【The invention's effect】
5. The method for treating a flue gas according to claim 1, wherein the flue gas discharged from the heating equipment is passed through the adsorbent to adsorb and remove the harmful component, and the adsorbent is heated. Because it is mainly made of processed limonite, it can absorb and remove ammonia, sulfur oxides and nitrogen oxides contained in combustion exhaust gas, and it can also adsorb and decompose dioxins. The combustion exhaust gas can be rendered harmless and discharged into the atmosphere. Furthermore, since limonite does not react with ammonia, sulfur oxides, nitrogen oxides, and dioxins, it can be used stably over a long period of time.
[0029]
In particular,Since the heat treatment is performed at a temperature of 300 ° C. or more and less than 550 ° C., the adsorbent can be easily and inexpensively manufactured by the limonite heat treatment, and the treatment cost of the combustion exhaust gas can be reduced. Become.
[0031]
In the method for treating flue gas according to claim 4, since the heating facility is one of a dust incinerator and a sintering machine, it is harmful at low cost and efficiently from flue gas containing various harmful components. Components can be removed.
[0032]
The combustion exhaust gas treatment apparatus according to any one of claims 5 to 9, wherein the combustion exhaust gas treatment chamber is provided in the middle of the flow path of the combustion exhaust gas, and has a cross-sectional area larger than the cross-sectional area of the passage of the combustion exhaust gas. The adsorbing layer is provided with an adsorbent mainly composed of limonite that has been heated and made porous, and a holding member that holds the adsorbent. It becomes possible to simplify. Further, since the used adsorbent is mainly composed of iron, it can be recycled as a raw material for iron making.
[0033]
In particular, in the combustion exhaust gas treatment apparatus according to claim 6, since the holding member is a heat-resistant net, when the adsorption layer is provided in the combustion exhaust gas treatment chamber, the surface area of the adsorbent with which the combustion exhaust gas contacts is further increased. It can be kept large, and the removal efficiency of harmful components can be improved.
[0034]
In the combustion exhaust gas treatment device according to claim 7, the adsorption layer is formed by granulating and heating the limonite that has been pulverized and heat-treated, and spraying it onto the net, so that the adsorption layer can be manufactured easily and at low cost. Thus, the cost of the combustion exhaust gas treatment device can be reduced.
[0035]
In the combustion exhaust gas processing apparatus according to claim 8, since the holding member is a heat-resistant container having air permeability, the container can be suspended or placed in the flow path, and the adsorption layer can be flown. It can be easily constructed in the road.
[0036]
In the combustion exhaust gas treatment apparatus according to claim 9, since the adsorption layer is formed by granulating and charging limonite that has been pulverized and heat-treated, the adsorption layer can be easily produced. Become. Further, the used adsorbent can be easily recovered by taking it out of the container, and recycling of the used adsorbent as an iron-making raw material is promoted.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a flue gas treatment apparatus according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of a combustion exhaust gas treatment apparatus according to a second embodiment of the present invention.
FIG. 3 is an explanatory diagram showing the conversion of chlorobenzene to carbon dioxide by limonite.
[Explanation of symbols]
10: Combustion exhaust gas treatment device, 11: dust incinerator, 12: cooler, 13: combustion exhaust gas treatment chamber, 14: dust collector, 15: chimney, 16-19: piping, 20: combustion exhaust gas treatment chamber main body, 21: Adsorbent, 22: dust collection net, 23: adsorption layer, 24: combustion exhaust gas treatment device, 25: sintering machine, 26: combustion exhaust gas treatment chamber, 27: dust collection machine, 28: chimney, 29-31: piping, 32 : Raw material hopper, 33: Chute, 34: Sintering furnace, 35: Wind box, 36: Main duct, 37: First low temperature side duct part, 38: High temperature side combustion air box, 39: Second low temperature side duct part, 40: piping, 41: blower, 42: intermediate temperature side duct part, 43: first high temperature side duct part, 44: intermediate temperature side combustion air box, 45: second high temperature side duct part

Claims (9)

In a method for treating flue gas exhausted from a heating facility and containing harmful components through an adsorbent and adsorbing and removing the harmful components,
The adsorbent was pulverized to 1 to 10 μm , mainly composed of limonite which was heated and heated for 10 to 1800 seconds at a temperature of 300 ° C. or more and less than 550 ° C. and granulated. Te, further, processing method of flue gas, characterized that you remove dioxin combustion in the exhaust gas temperature of the combustion exhaust gas as 300 to 400 ° C.. 2. The method for treating a combustion exhaust gas according to claim 1, wherein the granulated adsorbent has a particle size in the range of 1 to 3000 [mu] m, and sprays the adsorbent onto a heat-resistant net to form an adsorbent layer. A method for treating combustion exhaust gas characterized by the above. 2. The method for treating a combustion exhaust gas according to claim 1 , wherein the granulated adsorbent has a particle size in a range of 1 to 50 mm, and the adsorbent is filled in a heat-resistant container having air permeability and adsorbed. Combustion exhaust gas treatment method characterized by comprising a layer .   The method for treating a combustion exhaust gas according to any one of claims 1 to 3, wherein the heating equipment is any one of a dust incinerator and a sintering machine. A flue gas treatment device that removes harmful components including dioquine from flue gas discharged from a heating facility,
Provided in the middle of the flow path of the combustion exhaust gas, have a larger cross-sectional area than the flue gas passage cross-sectional area of the flow passage, a combustion exhaust gas treatment chamber is temperature 300 to 400 ° C. of the combustion exhaust gas flowing,
An adsorption layer provided in the combustion exhaust gas treatment chamber,
Adsorption layer is ground to 1 to 10 [mu] m, is heat treated in flowing 10-1800 seconds at temperatures below 300 ° C. or higher and 550 ° C. and mainly limonite became porous and granulated adsorbent, and A combustion exhaust gas treatment apparatus having a holding member for holding the adsorbent.   6. A combustion exhaust gas treatment apparatus according to claim 5, wherein the holding member is a heat-resistant net. The combustion exhaust gas treatment apparatus according to claim 6, wherein the adsorption layer is formed by granulating the limonite pulverized and heat-treated in a range of 1 to 3000 µm and spraying it on the net. Processing equipment.   6. A combustion exhaust gas treatment apparatus according to claim 5, wherein the holding member is a heat-resistant container having air permeability. 9. The apparatus for treating a flue gas according to claim 8, wherein the adsorption layer is formed by granulating the limonite that has been pulverized and heat-treated into a range of 1 to 50 mm and filling the vessel. Combustion exhaust gas treatment equipment.

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