JP2001227332A - Exhaust gas denitrification system for ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas denitrification system for a ship, for removing nitrogen oxides in exhaust gas from a diesel engine for the ship. SOLUTION: A NOx removal device 110 for removing nitrogen oxides in exhaust gas 10 is interposed on an exhaust pipe 101 for discharging the exhaust gas 10 from a diesel engine 100 for a ship.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas denitration system for a ship for denitrifying nitrogen oxides of exhaust gas from, for example, a marine diesel engine.

[0002]

2. Description of the Related Art In general, exhaust gas exhausted by driving an internal combustion engine for a vehicle or a ship contains nitrogen oxides and the like. Although there has been no regulation for exhaust gas from diesel engines in ships, the regulation has been agreed in the future, but if regulations are agreed in the future, it will be retroactive to January 2000 that the nitrogen oxide emissions from marine engines Products are also subject to regulations.

[0003]

Accordingly, the following proposals have been made as a method for preventing the emission of nitrogen oxides from combustion exhaust gas.

[0004] In order to reduce nitrogen oxides, it has been proposed to lower the combustion temperature, the combustion time, and the like. However, the reduction in fuel consumption and the increase in smoke generation are in conflict with each other, which is a problem.

[0005] Further, inhibition of the nitrogen oxide reduction reaction by particulates (including soot and tar components) contained in the exhaust gas of the diesel engine also occurs.

[0006] Further, there is a problem in that a reaction inhibition due to sulfur oxides (SOx) in the exhaust gas occurs in the denitration apparatus.

[0007] In view of the above problems, an object of the present invention is to provide a ship exhaust gas denitration system for denitrifying nitrogen oxides of exhaust gas from a marine diesel engine.

[0008]

Means for Solving the Problems The invention of a ship exhaust gas denitration system according to claim 1 for solving the above-mentioned problems is provided by an exhaust pipe for discharging exhaust gas from a marine diesel engine. Characterized by interposing a denitration device for removing water.

According to a second aspect of the present invention, in the first aspect, the marine diesel engine has an exhaust gas temperature of 30.
It is a two-cycle diesel engine at 0 ° C or lower.

According to a third aspect of the present invention, in the first aspect, a fine particle removing device for removing fine particles in the exhaust gas is interposed on the upstream side of the interposed denitration device. .

[0011] The invention of claim 4 is characterized in that, in claim 3, a desulfurization device is interposed on the upstream side or downstream side of the interposed fine particle removing device.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the NOx oxidizing device is interposed on the upstream side of the interposed NOx removing device and the NOx removal is performed by a scrubber means. It is characterized by improving efficiency.

According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the denitration apparatus is a scrubber denitration using seawater or an alkaline solution.

According to a seventh aspect of the present invention, in any one of the first to fourth aspects, the denitration apparatus uses a denitration catalyst.

[0015] The denitration catalyst is one in which an activator containing at least one transition metal oxide such as V, Mn or Cr is supported on an oxide carrier containing TiO ₂ or a carbon material carrier such as ACF. Is preferred.

[0016] The invention of claim 8 is characterized in that, in claim 7, the denitration catalyst supports at least one transition metal oxide.

According to a ninth aspect of the present invention, in the seventh aspect, the denitration catalyst is activated carbon fiber.

According to a tenth aspect of the present invention, in the third aspect, the fine particle removing device collects the fine particles in the exhaust gas, and removes the fine particles from the surface of the fine particles collected by the collecting means. And a catalyst adhering means for adhering a catalyst solution.

[0019] In the invention of claim 11, in claim 10, the catalyst adhering means for adhering the catalyst solution to the surface of the fine particles is provided with a spray means for spraying the catalyst solution to the collecting means for collecting the fine particles. It is characterized by becoming.

According to a twelfth aspect of the present invention, in the tenth aspect, the catalyst adhering means for adhering the catalyst solution to the surface of the fine particles is a dipping means for dipping the collecting means for collecting the fine particles in the catalyst solution. It is characterized by the following.

[13] The invention of claim 13 is the invention according to claim 10, wherein the catalyst solution is an aqueous catalyst solution containing at least one kind of alkali metal or alkaline earth metal, seawater, or at least one of the above alkali metal or alkaline earth metal. 1
It is a seawater containing seeds.

According to a fourteenth aspect, in the tenth aspect, a catalyst is supported on the collection means.

According to a fifteenth aspect of the present invention, in the tenth aspect, the trapping means for trapping the fine particles is formed by laminating flat filters and alternately closing the ends. Fine particles in the exhaust gas are attached to the surface of the filter, a catalyst solution is sprayed on the surface of the fine particles, and after drying, the unburned fine particles in the exhaust gas are burned.

According to a sixteenth aspect of the present invention, in the tenth aspect, the trapping means for trapping the fine particles is a laminated filter formed by bending a flat filter, and the fine particles in the exhaust gas are deposited on the surface of the filter. The method is characterized in that the catalyst solution is sprayed onto the surface of the fine particles, and the unburned fine particles in the exhaust gas are burned after drying.

[0027] The invention of a method for denitrifying exhaust gas from a ship according to claim 17 is characterized in that nitrogen oxides in exhaust gas discharged from a marine diesel engine are removed.

The invention of claim 18 is characterized in that, in claim 17, after collecting and decomposing fine particles in exhaust gas, nitrogen oxides in the exhaust gas are removed.

[0027] The invention of claim 19 is characterized in that, in claim 18, the collecting means on the surface of the fine particles is immersed in a catalyst solution, and the catalyst solution is attached to the surface of the collected fine particles. I do.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

[First Embodiment] A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram of a ship exhaust gas denitration system according to the present embodiment. FIG.
As shown in FIG. 1, the exhaust gas denitration system for a ship according to the present embodiment
The exhaust pipe 101 for discharging the exhaust gas is provided with a denitration device 110 for removing nitrogen oxides in the exhaust gas 10.

Although the denitration apparatus 110 of the present invention is not particularly limited, there are a scrubber denitration method using a scrubber and a catalyst denitration method filled with a denitration catalyst. The scrubber denitration method uses a spray type or filling type scrubber device, and as the scrubber liquid, for example, seawater or an alkaline solution is used. Here, when using seawater, it is not necessary to separately mount an alkaline solution, which is preferable. At this time, denitration can be carried out efficiently by installing a NO oxidizer before the scrubber. The NO oxidizing device is not particularly limited, but may be an oxidizing catalyst containing at least one of a noble metal and a transition metal, or may be oxidized by blowing ozone generated from an ozone generator.

In the present invention, the catalytic denitration method is not particularly limited. Examples of the denitration catalyst include V, Mn, Cr and the like on an oxide carrier containing TiO ₂ or a carbon material carrier such as ACF. It is preferable to support an activator containing at least one transition metal oxide.
In the case of catalytic denitration, it is preferable to add ammonia or urea water as a NOx reducing agent. Further, an ACF denitration catalyst using activated carbon fibers (ACF) can be exemplified.

In the present embodiment, a particulate removing means 120 for removing particulates is interposed on the upstream side of the above-mentioned denitrification apparatus so as to suppress the reduction of the denitration rate by the particulates in the denitration apparatus 110.

Here, the fine particle removing means 120 is not particularly limited. For example, a DPF (Diesel Particulate Filtration) using a ceramic honeycomb filter or the like is used.
ter), and collecting fine particles in the DPF,
Since the exhaust resistance increases as the amount of deposition increases, it is burned and removed for regeneration. Further, dust removing means such as a bag filter may be used.

Further, a particle removing device as shown in FIG. 7 may be used. As shown in FIG. 7, the particulate removal device according to the present embodiment is a particulate removal device for removing particulates in exhaust gas 10 from a diesel engine 100, and is a collection device that captures the particulates. A disc-shaped filter 11 as a means and a spray 13 having a plurality of nozzles (spray type, shower type, etc.) 13a as a catalyst adhering means for adhering the catalyst solution 12 to the surface of the fine particles collected by the disc-shaped filter 11 It is provided to burn and decompose unburned fine particles while covering the whole collected fine particles with a catalyst.

The apparatus for removing particulates according to the present embodiment uses a disc-shaped filter 11 having a shaft center in the vertical axis direction, and a part of the filter 11 is rotatably interposed in a flue 21 of exhaust gas. A collection zone 22 for collecting fine particles in the exhaust gas 10 in the flue 21 and a filter 11 for collecting fine particles are rotated, and the catalyst solution 12 supplied from the catalyst storage tank 23 outside the flue is sprayed by the spraying means 13. It comprises a catalyst carrying zone 24 to be sprayed, and a combustion zone 25 in which the carried catalyst enters the flue 21 again and the unburned portion is burned by the combined use of the heat of the exhaust gas 10 and the catalytic action.

In the catalyst storage tank 23, K ₂ CO ₃ or seawater as an alkali metal catalyst solution is supplied from a storage tank 26 and stored therein, and is stirred by a stirring means 27. The inside of the catalyst storage tank 23 is
The remaining catalyst solution 12 sprayed in 4 is recovered, and unburned C (carbon) may flow down at that time.
It contains the unburned C.

According to the present embodiment, the fine particles in the exhaust gas 10 are collected on the surface of the filter 11 in the fine particle collecting zone 22, and the collected fine particles are separated by the catalyst solution 12 in the catalyst supporting zone 24. And the catalyst is dried as the filter 12 rotates,
By burning again in the combustion zone 25 in the flue,
At a low temperature of about 00 ° C., unburned components (soot, tar, etc.) in the fine particles can be decomposed, and the clean gas 28 from which fine particles causing wear have been decomposed and removed can be supplied to the denitration device 110. .

Here, the catalyst used in the above-mentioned fine particle removing device contains at least one of alkali metals and alkaline earth metals such as Na and K such as potassium carbonate and sodium carbonate. In addition, seawater can be used as an alkali catalyst. Further, at least one of the above alkali metals or alkaline earth metals may be contained in seawater.

In the present invention, the alkali catalyst solution is sprayed so as to cover the surface of the fine particles collected by the filter,
By impregnating and supporting the catalyst, the catalyst can be uniformly arranged. As a result, the combustion field can be made uniform, and the catalyst can be combusted on the low temperature side (300 ° C. or lower). As a result, the efficiency of removing fine particles from the exhaust gas of the two-cycle diesel engine does not decrease.

Therefore, when burning the fine particles, abnormal combustion by a heater or the like is prevented, and the catalyst solution is sprayed depending on the combustion temperature (the concentration of the catalyst solution, the spray amount, the spray time,
The combustion temperature can be controlled by adjusting the rotation speed of the filter.

Since the filter material of the filter 11 repeats combustion and spraying of an aqueous solution, it is necessary to use a material having excellent thermal shock resistance. Examples of the heat shock resistant filter include a metal filter, a heat-treated ceramic filter, and the like.

Further, a laminated metal mesh type filter obtained by laminating a metal filter on a support layer holding filter strength, or a laminated metal nonwoven fabric type formed by laminating a metal nonwoven fabric on a support layer holding filter strength A filter can be exemplified.

Further, as shown in FIG.
A ceramics layer 32 may be disposed on the upper surface side of 1 and a laminated ceramics filter 34 including a protective mesh layer 33 for protecting the ceramics layer 32 may be used.

The filter may carry a metal catalyst such as platinum as required. Here, in addition to platinum, for example, rhodium, palladium and the like, and as the oxide catalyst, for example, titanium oxide, alumina oxide, cordierite, alumina-silica, zeolite, porous silicate, porous aluminate and the like, perovskite-type structure, A composite oxide having a spinel structure can be exemplified, but the present invention is not limited thereto. Thereby, on the surface side of the filter, the decomposition efficiency can be further improved by the combined effect of the catalytic action of the catalyst contacting the fine particles and the catalytic action of the alkali catalyst attached to the fine particles.

FIG. 8B shows the operation and effect of the removal of fine particles by the catalyst of the present invention. As shown in FIG. 8B, first, the fine particles 10 a in the exhaust gas adhere to the surface of the filter 11. Next, when the catalyst solution 12 is sprayed, the catalyst solution 12 is dispersed.
Covers the surface of the fine particles. When the catalyst solution 12 begins to cover the fine particles 10a, the catalyst solution 12
Begins to permeate. Then, when dried, the fine particles 10
The catalyst solution covering the surface of a is dried, and the component exhibiting the catalytic activity remains in a state of being uniformly dispersed on the surface of the fine particles. Further, the catalyst solution that has entered the inside of the fine particles is also dried, and the component having the catalytic activity remains uniformly inside the fine particles. After that, the catalytic action acts not only on the surface but also inside of the fine particles by combustion, and complete combustion is possible.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic diagram of a ship exhaust gas denitration system according to the present embodiment. FIG.
As shown in FIG. 1, the exhaust gas denitration system for a ship according to the present embodiment
An exhaust pipe 101 for discharging zero gas is provided with a denitration device 110 for removing nitrogen oxides in the exhaust gas 10, and a desulfurization device 130 is provided upstream of the denitration device 110. It is. Note that reference numeral 102 in the drawing indicates an induction blower that guides exhaust gas to the chimney side. This desulfurization device 1
By providing 20, for example, low-quality heavy oil (sulfur (S) content is high (several hundred to several thousand ppm) as in ships and the like.
Even in the case where heavy oil such as C heavy oil) is used, or when lubricating oil for a piston is used, the desulfurization in the desulfurization device 120 can reduce the emission of sulfur oxides (SOx) in the exhaust gas. .

In this embodiment, the fine particle removing device 1 is used.
Although the desulfurization device 120 is provided on the downstream side of the device 10, the present invention is not limited to this. The desulfurization device 120 may be provided on the upstream side of the fine particle removal device 110. It may be arranged on the downstream side.

When the desulfurization device 120 is installed downstream of the particulate removal device 120 as in this embodiment, desulfurization is performed inside the desulfurization device 120,
The fine particles can be removed, the effect of removing the fine particles can be further enhanced, and the fine particle removing device 110 may not be required if necessary.

The desulfurization device 120 includes, for example, a seawater scrubber system for desulfurization using seawater, and an ACF for converting SO ₂ into sulfuric acid by oxidizing activity of ACF (activated carbon fiber).
Although a desulfurization method and the like can be exemplified, the present invention is not limited to these.

[Third Embodiment] A third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram of a ship exhaust gas denitration system according to the present embodiment. FIG.
As shown in FIG. 1, the exhaust gas denitration system for a ship according to the present embodiment
A denitration device 110 using an ACF catalyst for removing nitrogen oxides in the exhaust gas 10 is provided in the exhaust pipe 101 for discharging the exhaust gas 10, and a desulfurization device 130 is provided upstream of the denitration device 110. It is. Further, in the present embodiment, in order to improve the denitration efficiency of the ACF denitration device 110, the heat of the exhaust gas 10 (heat of about 250 ° C. is recovered) between the fine particle removal means 120 and the desulfurization device 130. The heat recovered by the gas gas heater 140 is provided between the desulfurization device 130 and the ACF denitration device 110 while the gas gas heater 140 to be recovered is interposed.
0 (apply heat of about 180 ° C. to exhaust gas)
A gas gas heater 141 is interposed.

Thus, the heat is efficiently used by installing the gas gas heater 140 and the gas gas heater 141, the denitration reaction is performed at 180 ° C. to 150 ° C. in the ACF denitration apparatus, and the denitration system is efficiently performed. be able to.

[Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic diagram of a ship exhaust gas denitration system according to the present embodiment. FIG.
As shown in FIG. 1, the exhaust gas denitration system for a ship according to the present embodiment
A desulfurization / denitration apparatus 1 for simultaneously removing nitrogen oxides and sulfur oxides in the exhaust gas 10 is provided to an exhaust pipe 101 for discharging the exhaust gas 10.
50 and the desulfurization / denitration device 150
Oxidation device 16 for oxidizing NO to NO ₂ on the upstream side of
0 is interposed. Further, in the present embodiment, in order to improve the oxidation efficiency of the ACF oxidizer 160, the heat of the exhaust gas 10 is recovered between the fine particle removing means 120 and the ACF oxidizer 160 (heat of about 250 ° C. is recovered). In addition to interposing a gas gas heater 140 for recovering the exhaust gas, and for preventing the generation of white smoke from the chimney, the heat recovered by the gas gas heater 140 is disposed between the desulfurization / denitration device 150 and the induction blower 102. , And a gas gas heater 142 provided therein. Note that the preheating temperature for preventing white smoke is not particularly limited, and heat of, for example, 110 ° C. or more may be given to the exhaust gas.

Thus, heat is efficiently used by installing the gas gas heater 140 and the gas gas heater 141, an oxidation reaction is performed at 180 ° C. to 150 ° C. in the ACF oxidizing apparatus, and NO in the exhaust gas 10 is reduced to NO. Oxidation to ₂ improves the efficiency of removing nitrogen oxides in scrubber denitration and the like, and enables an efficient denitration system.

[Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic diagram of a ship exhaust gas denitration system according to the present embodiment. FIG.
As shown in FIG. 1, the exhaust gas denitration system for a ship according to the present embodiment
A desulfurization / denitration apparatus 1 for simultaneously removing nitrogen oxides and sulfur oxides in the exhaust gas 10 is provided to an exhaust pipe 101 for discharging the exhaust gas 10.
50 and the desulfurization / denitration device 150
A particle removing device 120 is interposed on the upstream side of the above. In the present embodiment, the desulfurization / denitration device 150
Ozone (O ₃ ) from the ozone generator 161 is supplied between the fine particle removing means 120 and the desulfurization / denitration device 150 in order to improve the nitrogen oxide removal efficiency. By supplying this ozone (O ₃ ), exhaust gas 1
NO in 0 is oxidized to NO ₂ to improve the efficiency of removing nitrogen oxides in scrubber desulfurization and denitration, etc., so that the denitration system can be efficiently performed.

[Sixth Embodiment] A sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic diagram of a ship exhaust gas denitration system according to the present embodiment. FIG.
As shown in FIG. 1, the exhaust gas denitration system for a ship according to the present embodiment
A desulfurizer 130 for removing sulfur oxides in the exhaust gas 10 and a denitrifier 110 for removing nitrogen oxides are interposed in an exhaust pipe 101 for exhausting gas from the exhaust gas 10. And a fine particle removing device 120 interposed therebetween. In the present embodiment, the denitration device 11
In order to improve the efficiency of removing nitrogen oxides of nitrogen, a plasma oxidation device 162 is interposed between the desulfurization device 130 and the denitration device 110. With the installation of the plasma oxidizing device 162, NO in the exhaust gas 10 is oxidized to NO ₂ , the efficiency of removing nitrogen oxides in scrubber denitration or the like is improved, and the denitration system can be efficiently performed.

In this embodiment, in order to improve the oxidation efficiency of the plasma oxidizer 162, the desulfurizer 13
0 and the plasma oxidation oxidizer 162
A gas gas heater 140 for recovering the heat of the air (recovering heat of about 250 ° C.) is interposed, and the denitration device 110 and the induction blower 10 are used to prevent the generation of white smoke from the chimney.
A gas gas heater 142 is provided between the first and second gas heaters to apply the heat recovered by the gas gas heater 140 to the exhaust gas 10 (apply heat of about 150 ° C. to the exhaust gas).

[Seventh Embodiment] Next, in addition to the spraying means for spraying the catalyst solution onto the filter 11 which has collected the fine particles as in the first embodiment, the collecting means which has collected the fine particles An example of a fine particle removing apparatus using a dipping means for dipping a means in a catalyst solution is shown.

Hereinafter, in the present embodiment, a device for removing fine particles in exhaust gas, which uses a disk filter and carries a catalyst by immersion means, will be described. FIG. 9 is a schematic view of an apparatus for removing particulates in exhaust gas according to the seventh embodiment. As shown in FIG. 9, the apparatus for removing particulates in exhaust gas according to the present embodiment uses a disk-shaped filter 11 having an axis in a direction orthogonal to the vertical axis direction, and a part of the filter 11 A collection zone 22 rotatably interposed in the flue 21 for collecting fine particles in the exhaust gas 10 in the flue.
Then, the filter 11 capturing the fine particles is rotated, and the catalyst supporting zone 24 for immersing the filter 11 in the catalyst storage tank 23 outside the flue, and the supported catalyst enters the flue 21 again and burns at the temperature of the combustion gas. And a combustion zone 25. Since the filter is immersed in the catalyst holding zone 24 in the storage tank 23, the storage tank 23 contains unburned C (carbon) attached to the surface. Since the action of decomposing the fine particles is the same as that of the first embodiment, the description is omitted.

This immersion type is suitable for exhaust gas treatment of a land-based stationary internal combustion engine. However, when traveling on the sea or on land, it is preferable to provide a means for preventing vibration in order to stabilize the treatment. I just need.

[Eighth Embodiment] In this embodiment,
Unlike the embodiment using the rotary filter described above,
The following describes a device for removing particulates in exhaust gas that uses a fixed filter and carries a catalyst by spraying means. FIG. 10 is a schematic diagram of an apparatus for removing particulates in exhaust gas according to the eighth embodiment. As shown in FIG. 10, in the apparatus for removing particulates in exhaust gas according to the present embodiment, the collecting means for capturing the particulates is a fixed prismatic filter 71, and the particulates in the exhaust gas 10 are filtered by the filter 71. The spray nozzles 72A to 72D of the catalyst attaching means for attaching the catalyst solution 12 to the outside and attaching the catalyst solution 12 to the surface of the fine particles are provided on the outer peripheral side, and the catalyst solution 12 is sprayed on the surface of the filter 71 in order. It burns fine particles.

In the present embodiment, the fixed type filter is a prismatic type, but the present invention is not limited to this. For example, a cylindrical type filter or a polygonal type filter may be used, and the catalyst solution 12 May be sequentially sprayed.

[Ninth Embodiment] In this embodiment,
The following describes a device for removing particulates in exhaust gas that uses a fixed filter and carries a catalyst by spraying means. FIG. 11 is a schematic diagram of an apparatus for removing particulates in exhaust gas according to the ninth embodiment. As shown in FIG. 11, in the apparatus for removing particulates in exhaust gas according to the present embodiment, the trapping means for trapping particulates has a laminated filter 91 having a shape obtained by folding a single planar filter into a groove shape. And exhaust gas 1
The catalyst solution 12 is sprayed on the surface of the filter 91 by spraying the catalyst solution 12 onto the surface of the filter 91 by an injection nozzle (not shown). After drying, the unburned particles in the exhaust gas are removed. It burns. Reference numeral 92 denotes a closed portion.

Further, the flat filters may be stacked in multiple stages, and the end faces may be alternately closed by closing plates 92 to form the stacked filter 91. Since the laminated filter 91 of the present embodiment penetrates a portion different from the closed portion, it is easy to wash and remove unburned matter adhering to the filter surface.

[0064]

As described above, according to the first aspect of the present invention, a denitration apparatus for removing nitrogen oxides from exhaust gas is provided to an exhaust pipe for discharging exhaust gas from a marine diesel engine. , It is possible to reduce nitrogen oxides in the exhaust gas.

According to the second aspect of the present invention, in the first aspect, the marine diesel engine is a two-cycle diesel engine having an exhaust gas temperature of 300 ° C. or less. The configuration can be made compact.

According to the third aspect of the present invention, in the first aspect, a fine particle removing device for removing fine particles in exhaust gas is interposed on the upstream side of the interposed denitration device.
Denitration can be performed while removing fine particles in the exhaust gas.

According to a fourth aspect of the present invention, in the third aspect, a desulfurization device is interposed on the upstream side or the downstream side of the interposed fine particle removing device, so that the sulfur in the exhaust gas can be reduced. Denitration can be performed while removing oxides.

According to the fifth aspect of the present invention, in any one of the first to fourth aspects, a NO oxidation device is interposed on the upstream side of the interposed denitration device. , N
O can be oxidized to NO ₂ to improve the denitration efficiency by a scrubber or the like.

According to the sixth aspect of the present invention, in any one of the first to fourth aspects, the denitration apparatus is a scrubber denitration using seawater or an alkaline solution. Efficiency is improved. When seawater is used, there is no need to separately mount an alkaline solution, and it is economical to effectively use seawater.

According to the invention of claim 7, in any one of claims 1 to 4, the denitration apparatus uses a denitration catalyst, so that the denitration effect is improved by the catalytic action.

According to the invention of claim 8, in claim 7, the denitration catalyst comprises at least one transition metal oxide.
Since the seeds are supported, the denitration effect is improved by the catalytic action of the active substance.

According to the ninth aspect of the present invention, in the seventh aspect, since the denitration catalyst is activated carbon fiber (ACF), the denitration effect is improved by the ACF catalyst.

According to the tenth aspect, the third aspect is provided.
In the above, the fine particle removing device comprises a collecting means for collecting fine particles in the exhaust gas, and a catalyst attaching means for attaching a catalyst solution for removing the fine particles to the surface of the fine particles collected by the collecting means. Therefore, it is possible to completely decompose the nitrogen oxides in the exhaust gas while removing the fine particles.

According to the invention set forth in claim 11, claim 1 is provided.
0, the catalyst adhering means for adhering the catalyst solution to the surface of the fine particles is provided with a spray means for spraying the catalyst solution to the collecting means for collecting the fine particles, so that the surface of the fine particles can be efficiently covered. . Also, spraying can be performed stably even when there is vibration or the like.

According to the invention of claim 12, claim 1 is
0, the catalyst adhering means for adhering the catalyst solution to the surface of the fine particles is an immersion means for immersing the collecting means for collecting the fine particles in the catalyst solution. The surface can be covered.

According to the invention of claim 13, claim 1 is
0, wherein the catalyst solution is an aqueous catalyst solution containing at least one alkali metal or alkaline earth metal, seawater,
Alternatively, since it is seawater containing at least one of the above alkali metals or alkaline earth metals, the cost of the catalyst is low and the catalyst solution after spraying can be reused.

According to the invention of claim 13, claim 1
0, the catalyst is supported on the collecting means,
It is possible to synergistically decompose the fine particles by a catalytic effect other than the alkali catalyst.

According to the invention of [claim 14], claim 1
0, the collecting means for collecting the fine particles is a stacked filter in which flat filters are stacked and the ends are alternately closed, and the fine particles in the exhaust gas adhere to the surface of the filter; Spray the catalyst solution on the fine particle surface,
Since the unburned fine particles in the exhaust gas are burned after drying, the fine particles can be collected well, and the fine particles can be burned and decomposed.

According to the invention set forth in claim 15, claim 1 is provided.
In 0, the collecting means for collecting the fine particles is a laminated filter formed by bending a flat filter, the fine particles in the exhaust gas are adhered to the surface of the filter, and a catalyst solution is sprayed on the surface of the fine particles and dried. Since the unburned fine particles in the exhaust gas are burned later, the fine particles can be collected well and the fine particles can be decomposed by combustion. Further, the device can be manufactured compactly. Further, removal of unburned substances is easy.

According to the method for denitrifying exhaust gas from a ship according to claim 16, nitrogen oxides in the exhaust gas discharged from the marine diesel engine are removed, so that nitrogen oxides in the exhaust gas can be reduced. it can. In particular, when the marine diesel engine is a two-cycle diesel engine having an exhaust gas temperature of 300 ° C. or less, it is not necessary to perform denitration at a high temperature, and the device configuration can be made compact.

According to the invention of [claim 17], claim 1 is
In 6, the nitrogen oxides in the exhaust gas are removed after the fine particles in the exhaust gas are collected and decomposed, so that the nitrogen oxides in the exhaust gas can be completely decomposed together with the removal of the fine particles.

According to the invention of claim 18, claim 1 is
In 7, the collecting means on the surface of the fine particles is immersed in the catalyst solution, and the catalyst solution is attached to the surface of the collected fine particles, so that the surface of the fine particles can be efficiently covered. Also, spraying can be performed stably even when there is vibration or the like.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a ship exhaust gas denitration system according to a first embodiment.

FIG. 2 is a schematic diagram of a ship exhaust gas denitration system according to a second embodiment.

FIG. 3 is a schematic diagram of a ship exhaust gas denitration system according to a third embodiment.

FIG. 4 is a schematic diagram of a ship exhaust gas denitration system according to a fourth embodiment.

FIG. 5 is a schematic diagram of a ship exhaust gas denitration system according to a fifth embodiment.

FIG. 6 is a schematic diagram of a ship exhaust gas denitration system according to a sixth embodiment.

FIG. 7 is a schematic diagram of a particle removing device according to the first embodiment.

FIG. 8A is a configuration diagram of a filter, and FIG. 8B is a schematic diagram of a concept of decomposing fine particles.

FIG. 9 is a schematic diagram of a fine particle removing apparatus according to a seventh embodiment.

FIG. 10 is a schematic diagram of a particle removing apparatus according to an eighth embodiment.

FIG. 11 is a schematic diagram of a particle removing apparatus according to a ninth embodiment.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 10 Exhaust gas 100 Diesel engine 101 Exhaust pipe 102 Induction blower 110 Denitration device 120 Fine particle removal means 130 Desulfurization device 140, 141, 142 Gas gas heater 150 Desulfurization / denitration device 160 ACF oxidizer 161 Ozone generator 162 Plasma oxidizer 11 Disk filter 12 Catalyst solution 13a Nozzle 13 Spray 21 Flue 22 Capture zone 23 Catalyst storage tank 24 Catalyst carrying zone 25 Combustion zone 26 Storage tank 27 Stirrer 28 Clean gas 31 Support layer 32 Ceramic layer 33 Protective mesh layer 34 Laminated ceramic filter 71 Prismatic Filters 72A-D Injection nozzle 91 Laminated filter 92 Closed part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akinori Yasutake 5-717-1 Fukahori-cho, Nagasaki-shi, Nagasaki Sanishi Heavy Industries Co., Ltd. Nagasaki Research Institute (72) Inventor Yuichi Fujioka 5-717 Fukahori-cho, Nagasaki-shi, Nagasaki No. 1 In the Nagasaki Research Laboratory of Mitsubishi Heavy Industries, Ltd. (72) Inventor Akira Hattori 1-1, Akunoura-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd.Nagasaki Shipyard (72) Inventor Keiko Kobayashi Marunouchi, Chiyoda-ku, Tokyo No.5-1, Mitsuhishi Heavy Industries, Ltd. (72) Nobuaki Murakami 1-8-1, Koura, Kanazawa-ku, Yokohama-shi, Kanagawa Pref. AB15 BA14 CA02 CA18 GB01W GB01X GB05W GB06W GB07W GB09W GB10W GB10X GB13W HA07 HA16

Claims (19)

[Claims] 1. An exhaust gas denitration system for a ship, wherein a denitration device for removing nitrogen oxides in the exhaust gas is interposed in an exhaust pipe for discharging exhaust gas from a marine diesel engine. 2. The marine diesel engine according to claim 1, wherein the marine diesel engine has an exhaust gas temperature of 300 ° C.
An exhaust gas denitration system for a ship, comprising the following two-cycle diesel engine. 3. The exhaust gas denitration system for a ship according to claim 1, further comprising a particulate removal device that removes particulates in the exhaust gas upstream of the inserted denitration device. 4. The exhaust gas denitration system for a ship according to claim 3, wherein a desulfurization device is provided upstream or downstream of the interposed fine particle removal device. 5. The denitration efficiency of the scrubber means according to claim 1, wherein a NO oxidizing device is interposed on the upstream side of the interposed denitration device. Exhaust gas denitration system for ships. 6. The exhaust gas denitration system for a ship according to claim 1, wherein the denitration device is a scrubber denitration using seawater or an alkaline solution. 7. The exhaust gas denitration system for a ship according to any one of claims 1 to 4, wherein the denitration device uses a denitration catalyst. 8. The exhaust gas denitration system for a ship according to claim 7, wherein the denitration catalyst supports at least one transition metal oxide. 9. The exhaust gas denitration system for a ship according to claim 7, wherein the denitration catalyst is activated carbon fiber. 10. The fine particle removing device according to claim 3, wherein the fine particle removing device attaches a collecting means for collecting the fine particles in the exhaust gas, and a catalyst solution for removing the fine particles to the surface of the fine particles collected by the collecting means. An exhaust gas denitration system for a ship, comprising: 11. The method according to claim 10, wherein the catalyst adhering means for adhering the catalyst solution to the surface of the fine particles comprises spray means for spraying the catalyst solution to the collecting means for collecting the fine particles. Exhaust gas denitration system. 12. The ship according to claim 10, wherein the catalyst adhering means for adhering the catalyst solution to the surface of the fine particles is an immersion means for immersing the collecting means for collecting the fine particles in the catalyst solution. Exhaust gas denitration system. 13. The catalyst solution according to claim 10, wherein the catalyst solution is a catalyst aqueous solution containing at least one alkali metal or alkaline earth metal, seawater, or seawater containing at least one alkali metal or alkaline earth metal. An exhaust gas denitration system for ships, characterized in that: 14. The exhaust gas denitration system for a ship according to claim 10, wherein a catalyst is carried on the trapping means. 15. The filter according to claim 10, wherein the collecting means for collecting the fine particles is a stacked filter in which flat filters are stacked and the ends are alternately closed, and the fine particles in the exhaust gas are filtered. An exhaust gas denitration system for ships, wherein the catalyst solution is sprayed on the surface of the fine particles, and the unburned fine particles in the exhaust gas are burned after drying. 16. The particulate filter according to claim 10, wherein the trapping means for trapping the fine particles is a laminated filter obtained by bending a flat filter, and causing fine particles in exhaust gas to adhere to the surface of the filter. An exhaust gas denitration system for ships, wherein a catalyst solution is sprayed, and after drying, unburned fine particles in exhaust gas are burned. 17. A method for denitration of exhaust gas from a ship, comprising removing nitrogen oxides in exhaust gas discharged from a marine diesel engine. 18. The method according to claim 17, further comprising the step of collecting and decomposing fine particles in the exhaust gas and removing nitrogen oxides in the exhaust gas. 19. The exhaust gas denitration method for a ship according to claim 18, wherein the collecting means having the surface of the fine particles is immersed in a catalyst solution, and the catalyst solution is attached to the surface of the collected fine particles.