JP2014043819A - Denitrification apparatus, and denitrification method - Google Patents

Denitrification apparatus, and denitrification method Download PDF

Info

Publication number
JP2014043819A
JP2014043819A JP2012187215A JP2012187215A JP2014043819A JP 2014043819 A JP2014043819 A JP 2014043819A JP 2012187215 A JP2012187215 A JP 2012187215A JP 2012187215 A JP2012187215 A JP 2012187215A JP 2014043819 A JP2014043819 A JP 2014043819A
Authority
JP
Japan
Prior art keywords
temperature
denitration catalyst
upstream
reducing agent
downstream
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2012187215A
Other languages
Japanese (ja)
Other versions
JP6079056B2 (en
Inventor
Hiroyuki Kamata
博之 鎌田
Hiroaki Ohara
宏明 大原
Yoshinori Izumi
良範 泉
Isato Nakajima
勇人 中島
Noriyuki Yamada
敬之 山田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IHI Corp
Original Assignee
IHI Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by IHI Corp filed Critical IHI Corp
Priority to JP2012187215A priority Critical patent/JP6079056B2/en
Publication of JP2014043819A publication Critical patent/JP2014043819A/en
Application granted granted Critical
Publication of JP6079056B2 publication Critical patent/JP6079056B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Catalysts (AREA)
  • Supercharger (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

PROBLEM TO BE SOLVED: To efficiently remove NOx from exhaust gas by devising arrangement and structure of denitrification catalysts.SOLUTION: A denitrification apparatus 200 comprises: a supercharger 210 having a turbine 212 which rotates by exhaust gas transmitted from an engine 110, and a compressor 214 which compresses air by utilizing rotation of the turbine and introduces the compressed air to the engine; a high temperature denitrification catalyst 220 (upstream side denitrification catalyst) which is provided on the upstream side of the turbine and promotes reduction of nitric oxide contained in the exhaust gas on the upstream side; a low temperature denitrification catalyst 222 (downstream side denitrification catalyst) with activation temperature lower than that of the high temperature denitrification catalyst 220, which is provided on the downstream side of the turbine and promotes reduction of the nitric oxide contained in the exhaust gas on the downstream side; and a reducing agent introduction section 234 which introduces a reducing agent to the upstream side of the high temperature denitrification catalyst 220 and the upstream side of the low temperature denitrification catalyst 222.

Description

本発明は、エンジンの排ガス中に含まれる窒素酸化物を、還元剤を用いて窒素に還元する脱硝装置、および、脱硝方法に関する。   The present invention relates to a denitration apparatus and a denitration method for reducing nitrogen oxides contained in engine exhaust gas to nitrogen using a reducing agent.

船舶や、車両等のエンジンにおいて、化石燃料を燃焼させると、燃焼排ガス（排気ガス）が生じるが、この排気ガスには、窒素酸化物（以下、単にＮＯｘと称する）が含まれている。ＮＯｘは、大気汚染物質であるため、国や世界的な機関による濃度規制や、地方自治体による総量規制が行われている。したがって、エンジンから排出される排気ガスに含まれるＮＯｘ濃度が予め定められた規制値以上である場合には、ＮＯｘを除去するための脱硝装置に排気ガスを通過させる必要がある。   Combustion exhaust gas (exhaust gas) is generated when fossil fuel is burned in an engine such as a ship or a vehicle. This exhaust gas contains nitrogen oxides (hereinafter simply referred to as NOx). Since NOx is an air pollutant, concentration regulation by national and global organizations and total quantity regulation by local governments are performed. Therefore, when the concentration of NOx contained in the exhaust gas discharged from the engine is equal to or higher than a predetermined regulation value, it is necessary to pass the exhaust gas through a denitration device for removing NOx.

脱硝装置としては、ＮＯｘを還元するための還元剤と、ＮＯｘの還元を促進する脱硝触媒とを含んで構成される選択式触媒還元（Selective Catalytic Reduction）脱硝装置が普及している。選択式触媒還元脱硝装置を利用する場合、排気ガスと還元剤とを予め混合させておき、その混合気体を脱硝触媒に流通させることにより、還元剤が排気ガス中のＮＯｘを還元（分解）する。また、脱硝触媒は、ＮＯｘの還元効率を維持するために、予め定められた活性温度の下限値（例えば、３００℃程度）以上に保っておく必要がある。   As a denitration apparatus, a selective catalytic reduction denitration apparatus that includes a reducing agent for reducing NOx and a denitration catalyst that promotes the reduction of NOx is widely used. When a selective catalytic reduction denitration apparatus is used, exhaust gas and a reducing agent are mixed in advance, and the mixed gas is passed through the denitration catalyst so that the reducing agent reduces (decomposes) NOx in the exhaust gas. . Further, the denitration catalyst needs to be maintained at a predetermined lower limit (for example, about 300 ° C.) of the activation temperature in order to maintain the NOx reduction efficiency.

エンジンの排気路に脱硝触媒を配置する場合において、過給機のタービンの上流側に配置する構成と、下流側に配置する構成が考えられる。ここで、タービンの上流側に脱硝触媒を配置する構成を採る場合、エンジン負荷によっては、排気ガスの温度が高くなりすぎ、還元剤が酸化されてしまい、所望する脱硝効率が得られないおそれがある。一方、タービンの下流に脱硝触媒を配置する構成を採る場合、排気ガスの熱がタービンで消費されるため、タービンの下流の排気ガスの温度が、脱硝触媒の活性温度の下限値に到達しないことがある。   When the denitration catalyst is disposed in the exhaust path of the engine, a configuration in which the denitration catalyst is disposed on the upstream side of the turbocharger turbine and a configuration in which the denitration catalyst is disposed on the downstream side are conceivable. Here, when adopting a configuration in which a denitration catalyst is arranged upstream of the turbine, depending on the engine load, the temperature of the exhaust gas becomes too high, and the reducing agent may be oxidized, and the desired denitration efficiency may not be obtained. is there. On the other hand, when adopting a configuration in which the denitration catalyst is arranged downstream of the turbine, the exhaust gas heat is consumed by the turbine, so the temperature of the exhaust gas downstream of the turbine does not reach the lower limit of the activation temperature of the denitration catalyst. There is.

そこで、タービンの下流に脱硝触媒を設けておき、タービンの上流側の排気ガスを分岐し、分岐した上流側の排気ガスをタービンの下流側の排気ガスに合流させることで、タービンの下流側における排気ガスの温度低下を抑制する技術が開示されている（例えば、特許文献１）。また、脱硝触媒を活性温度に加熱するための加熱装置を別途設ける技術も開示されている（例えば、特許文献２）。   Therefore, a NOx removal catalyst is provided downstream of the turbine, the exhaust gas upstream of the turbine is branched, and the branched upstream exhaust gas is merged with the exhaust gas downstream of the turbine. A technique for suppressing a temperature drop of exhaust gas is disclosed (for example, Patent Document 1). In addition, a technique of separately providing a heating device for heating the denitration catalyst to the activation temperature is disclosed (for example, Patent Document 2).

特開２０１１−１４４７６５号公報JP 2011-144765 A 特許第３９２４０４６号Patent No. 3924046

しかし、特許文献１の技術では、エンジンから排出された排気ガスの温度が低く、脱硝触媒を活性温度にするために分岐量を多くすると、タービン効率が低下してしまう。また、特許文献２の技術を利用すると、ヒータ等の別途の加熱装置が必要となり、必要以上に電力や燃料を消費することとなる。また、加熱装置を設置するための専用のスペースが必要となる。特に、スペースが限られた船舶等では、加熱装置のための専用のスペースを確保するのが困難である場合もある。   However, in the technique of Patent Document 1, if the temperature of the exhaust gas discharged from the engine is low and the branch amount is increased in order to bring the denitration catalyst to the activation temperature, the turbine efficiency is lowered. Moreover, if the technique of patent document 2 is utilized, a separate heating device such as a heater will be required, and electric power and fuel will be consumed more than necessary. In addition, a dedicated space for installing the heating device is required. In particular, in a ship where space is limited, it may be difficult to secure a dedicated space for the heating device.

本発明は、このような課題に鑑み、脱硝触媒の配置および構成を工夫することで、排気ガスから効率よくＮＯｘを除去することが可能な脱硝装置、および、脱硝方法を提供することを目的としている。   In view of such problems, the present invention aims to provide a denitration apparatus and a denitration method capable of efficiently removing NOx from exhaust gas by devising the arrangement and configuration of a denitration catalyst. Yes.

上記課題を解決するために、本発明の脱硝装置は、エンジンから送出された排気ガスによって回転するタービン、および、タービンの回転を利用して空気を圧縮しエンジンに圧縮した空気を導入する圧縮機を有する過給機と、タービンの上流側に設けられ、上流側の排気ガスに含まれる窒素酸化物の還元を促進する上流側脱硝触媒と、タービンの下流側に設けられ、下流側の排気ガスに含まれる窒素酸化物の還元を促進する、上流側脱硝触媒よりも活性温度が低い下流側脱硝触媒と、上流側脱硝触媒の上流側、および、下流側脱硝触媒の上流側に還元剤を導入する還元剤導入部と、を備えたことを特徴とする。   In order to solve the above-described problems, a denitration apparatus of the present invention includes a turbine that is rotated by exhaust gas sent from an engine, and a compressor that compresses air using the rotation of the turbine and introduces compressed air into the engine. A turbocharger provided on the upstream side of the turbine, and an upstream denitration catalyst that promotes reduction of nitrogen oxides contained in the upstream exhaust gas, and a downstream exhaust gas provided on the downstream side of the turbine Introducing a reducing agent on the upstream side of the downstream denitration catalyst, upstream of the downstream denitration catalyst, and upstream of the downstream denitration catalyst, which promotes reduction of nitrogen oxides contained in And a reducing agent introducing section.

上記還元剤導入部は、上流側脱硝触媒の上流側、および、下流側脱硝触媒の上流側のいずれにも独立して還元剤を導入可能であり、タービンと下流側脱硝触媒との間を流通する排気ガスの温度である下流側温度を測定する温度測定部と、下流側温度が第１の閾値以上である場合、還元剤導入部を制御して、下流側脱硝触媒の上流側のみに還元剤を導入させる還元剤調整部と、を備えるとしてもよい。   The reducing agent introduction section can introduce the reducing agent independently to both the upstream side of the upstream denitration catalyst and the upstream side of the downstream side denitration catalyst, and circulates between the turbine and the downstream side denitration catalyst. If the downstream temperature is equal to or higher than the first threshold, the reducing agent introduction unit is controlled to reduce only the upstream side of the downstream denitration catalyst. And a reducing agent adjusting unit that introduces the agent.

上記温度測定部は、下流側温度とともに、エンジンと上流側脱硝触媒との間を流通する排気ガスの温度である上流側温度を測定し、還元剤調整部は、下流側温度が第１の閾値未満であり、上流側温度が第１の閾値より高い第２の閾値未満である場合、還元剤導入部を制御して、上流側脱硝触媒の上流側のみに還元剤を導入させるとしてもよい。   The temperature measuring unit measures the upstream side temperature, which is the temperature of the exhaust gas flowing between the engine and the upstream side denitration catalyst, together with the downstream side temperature, and the reducing agent adjusting unit has the downstream side temperature as the first threshold value. When the upstream temperature is lower than the second threshold value higher than the first threshold value, the reducing agent introduction unit may be controlled to introduce the reducing agent only upstream of the upstream denitration catalyst.

上記還元剤調整部は、下流側温度が第１の閾値未満であり、上流側温度が第２の閾値以上である場合、還元剤導入部を制御して、上流側脱硝触媒の上流側および下流側脱硝触媒の上流側に還元剤を導入させるとしてもよい。   When the downstream temperature is lower than the first threshold value and the upstream temperature is equal to or higher than the second threshold value, the reducing agent adjusting unit controls the reducing agent introduction unit to control the upstream side and downstream side of the upstream denitration catalyst. A reducing agent may be introduced upstream of the side denitration catalyst.

上記上流側脱硝触媒は、モリブデン（Ｍｏ）およびタングステン（Ｗ）のいずれか一方または双方を含み、モリブデン（Ｍｏ）およびタングステン（Ｗ）のいずれか一方または双方の含有量が、上流側脱硝触媒の活性金属種を構成する他の元素よりも多く、下流側脱硝触媒は、周期表の第５属から第１１属の元素の群から選択される１または複数の元素を含むとしてもよい。   The upstream denitration catalyst includes one or both of molybdenum (Mo) and tungsten (W), and the content of either one or both of molybdenum (Mo) and tungsten (W) is equal to that of the upstream denitration catalyst. More than the other elements constituting the active metal species, the downstream denitration catalyst may include one or more elements selected from the group of elements of Group 5 to Group 11 of the periodic table.

上記課題を解決するために、本発明の脱硝方法は、エンジンから送出された排気ガスによって回転するタービン、および、タービンの回転を利用して空気を圧縮しエンジンに圧縮した空気を導入する圧縮機を有する過給機と、タービンの上流側に設けられ、上流側の排気ガスに含まれる窒素酸化物の還元を促進する上流側脱硝触媒と、タービンの下流側に設けられ、下流側の排気ガスに含まれる窒素酸化物の還元を促進する、上流側脱硝触媒よりも活性温度が低い下流側脱硝触媒とを用いた脱硝方法であって、タービンと下流側脱硝触媒との間を流通する排気ガスの温度である下流側温度が第１の閾値以上である場合、下流側脱硝触媒の上流側のみに還元剤を導入し、下流側温度が第１の閾値未満であり、エンジンと上流側脱硝触媒との間を流通する排気ガスの温度である上流側温度が第１の閾値より高い第２の閾値未満である場合、上流側脱硝触媒の上流側のみに還元剤を導入し、下流側温度が第１の閾値未満であり、上流側温度が第２の閾値以上である場合、上流側脱硝触媒の上流側および下流側脱硝触媒の上流側に還元剤を導入することを特徴とする。   In order to solve the above-described problems, a denitration method of the present invention includes a turbine that is rotated by exhaust gas delivered from an engine, and a compressor that compresses air using the rotation of the turbine and introduces compressed air into the engine. A turbocharger provided on the upstream side of the turbine, and an upstream denitration catalyst that promotes reduction of nitrogen oxides contained in the upstream exhaust gas, and a downstream exhaust gas provided on the downstream side of the turbine Is a denitration method using a downstream denitration catalyst having an activation temperature lower than that of the upstream denitration catalyst, which promotes reduction of nitrogen oxides contained in the exhaust gas flowing between the turbine and the downstream denitration catalyst When the downstream temperature, which is the temperature of the engine, is equal to or higher than the first threshold value, the reducing agent is introduced only to the upstream side of the downstream denitration catalyst, the downstream temperature is less than the first threshold value, and the engine and the upstream denitration catalyst Between When the upstream temperature, which is the temperature of the exhaust gas passing therethrough, is lower than the second threshold value higher than the first threshold value, the reducing agent is introduced only to the upstream side of the upstream denitration catalyst, and the downstream temperature is the first threshold value. When the upstream temperature is equal to or higher than the second threshold value, the reducing agent is introduced into the upstream side of the upstream denitration catalyst and the upstream side of the downstream denitration catalyst.

本発明によれば、脱硝触媒の配置および構成を工夫することで、排気ガスから効率よくＮＯｘを除去することが可能となる。   According to the present invention, it is possible to efficiently remove NOx from the exhaust gas by devising the arrangement and configuration of the denitration catalyst.

脱硝システムを説明するための図である。It is a figure for demonstrating a denitration system. 高温脱硝触媒と、低温脱硝触媒の温度による脱硝率変化を説明するための図である。It is a figure for demonstrating the denitration rate change by the temperature of a high temperature denitration catalyst and a low temperature denitration catalyst. 脱硝装置を用いた脱硝方法の処理の流れを説明するための図である。It is a figure for demonstrating the flow of a process of the denitration method using a denitration apparatus. 脱硝装置を用いた脱硝方法の処理の流れを説明するためのフローチャートである。It is a flowchart for demonstrating the flow of a process of the denitration method using a denitration apparatus.

以下に添付図面を参照しながら、本発明の好適な実施形態について詳細に説明する。かかる実施形態に示す寸法、材料、その他具体的な数値等は、発明の理解を容易とするための例示にすぎず、特に断る場合を除き、本発明を限定するものではない。なお、本明細書及び図面において、実質的に同一の機能、構成を有する要素については、同一の符号を付することにより重複説明を省略し、また本発明に直接関係のない要素は図示を省略する。   Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

コンテナ船やタンカー等の大型船舶では、熱効率がよく、低質燃料油（重油）が使用できるためコスト面で有利である、ユニフロー型の２サイクルエンジン（２ストロークエンジン）が広く使用されている。このようなエンジンにおいて、化石燃料、例えば、ガソリン、軽油、重油、液化天然ガス（ＬＮＧ：Liquefied Natural Gas）、および液化石油ガス（ＬＰＧ：Liquefied Petroleum Gas）等の燃料を燃焼させると、その結果生じる排気ガスには、ＮＯｘが含まれる。   In large ships such as container ships and tankers, a uniflow type two-cycle engine (two-stroke engine), which is advantageous in terms of cost because it has high thermal efficiency and low-quality fuel oil (heavy oil) can be used, is widely used. Combustion of fuels such as fossil fuels such as gasoline, light oil, heavy oil, liquefied natural gas (LNG), and liquefied petroleum gas (LPG) in such engines results. The exhaust gas contains NOx.

そこで、近年、国際海事機関（ＩＭＯ：International Maritime Organization）が、船舶から排出される排気ガス中のＮＯｘ（窒素酸化物）を削減する規制を制定しており、一般海域においてＮＯｘの排出量を所定値までに制限し（２次規制）、大気汚染物質放出規制海域（ＥＣＡ：Emission Control Area）においては、ＮＯｘの排出量を、２次規制より低い値を上限として制限している（３次規制）。   Therefore, in recent years, the International Maritime Organization (IMO) has enacted regulations to reduce NOx (nitrogen oxides) in exhaust gas discharged from ships, and the amount of NOx emissions in the general sea area is predetermined. Limit to the value (secondary regulation), and limit the amount of NOx emission in the air pollution emission control sea area (ECA: Emission Control Area) up to a lower value than the secondary regulation (tertiary regulation) ).

このように国際海事機関が制定した規制を遵守すべく、船舶には、排気ガスに含まれるＮＯｘを還元するための脱硝装置を備えておく必要がある。以下、エンジンと、脱硝装置とを備え、エンジンから排出される排気ガス中のＮＯｘを還元する脱硝システムについて説明する。なお、以下の実施形態において、脱硝システムに用いるエンジンとしてユニフロー型の２ストロークエンジンを例に挙げて説明するが、他の形式の２ストロークエンジンや４ストロークエンジン等に脱硝システムを採用することもできる。   Thus, in order to comply with the regulations established by the International Maritime Organization, the ship needs to be equipped with a denitration device for reducing NOx contained in the exhaust gas. Hereinafter, a denitration system that includes an engine and a denitration device and that reduces NOx in exhaust gas discharged from the engine will be described. In the following embodiments, a uniflow type two-stroke engine will be described as an example of an engine used in the denitration system. However, the denitration system can be adopted in other types of two-stroke engines, four-stroke engines, and the like. .

（脱硝システム１００）
図１は、本実施形態にかかる脱硝システム１００を説明するための図である。図１中、物質（排気ガス、還元剤）の流れを実線で示し、信号の流れを破線で示す。図１に示すように、脱硝システム１００において、エンジン１１０から排出された排気ガスＸ１は、脱硝装置２００を通過することで、ＮＯｘ（窒素酸化物）が除去されて排気ガスＹとなり、外部へ放出される。 (Denitration system 100)
FIG. 1 is a view for explaining a denitration system 100 according to the present embodiment. In FIG. 1, the flow of substances (exhaust gas, reducing agent) is indicated by solid lines, and the flow of signals is indicated by broken lines. As shown in FIG. 1, in the denitration system 100, the exhaust gas X1 exhausted from the engine 110 passes through the denitration device 200, so that NOx (nitrogen oxide) is removed and becomes exhaust gas Y, which is discharged to the outside. Is done.

（脱硝装置２００）
本実施形態にかかる脱硝装置２００では、排気ガスＸ１に還元剤を導入し、還元剤の導入位置の下流に配した脱硝触媒で、排気ガスＸ１中のＮＯｘの還元を促進して窒素を生成する選択式触媒還元方式を採用している。 (Denitration device 200)
In the denitration apparatus 200 according to the present embodiment, a reducing agent is introduced into the exhaust gas X1, and the reduction of NOx in the exhaust gas X1 is promoted to generate nitrogen by a denitration catalyst disposed downstream of the introduction position of the reducing agent. Selective catalytic reduction method is adopted.

図１に示すように、脱硝装置２００は、排気ライン２０２と、過給機２１０と、高温脱硝触媒（上流側脱硝触媒）２２０と、低温脱硝触媒（下流側脱硝触媒）２２２と、温度測定部２３２と、還元剤導入部２３４と、還元剤調整部２３６とを含んで構成される。   As shown in FIG. 1, the denitration apparatus 200 includes an exhaust line 202, a supercharger 210, a high temperature denitration catalyst (upstream denitration catalyst) 220, a low temperature denitration catalyst (downstream denitration catalyst) 222, and a temperature measurement unit. 232, a reducing agent introduction unit 234, and a reducing agent adjustment unit 236.

排気ライン２０２は、エンジン１１０から排出された排気ガスＸ１が流通する排気路であって、後述する高温脱硝触媒２２０および低温脱硝触媒２２２が内設されている。   The exhaust line 202 is an exhaust passage through which the exhaust gas X1 exhausted from the engine 110 flows, and has a high-temperature denitration catalyst 220 and a low-temperature denitration catalyst 222 described later.

過給機２１０は、タービン２１２と、タービン２１２と同軸の圧縮機２１４とを含んで構成される。タービン２１２は、エンジン１１０から排出された排気ガスＸ１によって回転し、圧縮機２１４は、タービン２１２の回転を利用し、外部から導入される空気を圧縮してエンジン１１０への掃気圧を高める。こうすることで、エンジン１１０の出力を向上させることができる。   The supercharger 210 includes a turbine 212 and a compressor 214 that is coaxial with the turbine 212. The turbine 212 is rotated by the exhaust gas X1 exhausted from the engine 110, and the compressor 214 uses the rotation of the turbine 212 to compress air introduced from the outside to increase the scavenging pressure to the engine 110. By doing so, the output of the engine 110 can be improved.

高温脱硝触媒２２０は、担体と、担体に担持された活性金属種とを含んで構成され、後述する低温脱硝触媒２２２よりも活性温度が高い。高温脱硝触媒２２０の活性金属種は、少なくともモリブデン（Ｍｏ）およびタングステン（Ｗ）のいずれか一方または双方を含んで構成される。本実施形態において、高温脱硝触媒２２０は、酸化チタンを担体とし、酸化タングステンを活性金属種として構成される。なお、高温脱硝触媒２２０の活性金属種は、モリブデンおよびタングステン以外の他の元素を含んでもよいが、モリブデンおよびタングステンのいずれか一方または双方の含有量が、当該高温脱硝触媒２２０の活性金属種を構成する他の元素よりも多い必要がある。高温脱硝触媒２２０の活性金属種を構成する他の元素は、例えば、周期表の第５属から第１１属の元素の群（例えば、バナジウム（Ｖ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、鉄（Ｆｅ）、コバルト（Ｃｏ）、銅（Ｃｕ））から選択される１または複数の元素である。   The high temperature denitration catalyst 220 includes a carrier and an active metal species supported on the carrier, and has an activation temperature higher than that of a low temperature denitration catalyst 222 described later. The active metal species of the high-temperature denitration catalyst 220 includes at least one or both of molybdenum (Mo) and tungsten (W). In the present embodiment, the high-temperature denitration catalyst 220 is configured using titanium oxide as a carrier and tungsten oxide as an active metal species. The active metal species of the high-temperature denitration catalyst 220 may contain elements other than molybdenum and tungsten, but the content of either one or both of molybdenum and tungsten is different from the active metal species of the high-temperature denitration catalyst 220. It needs to be more than the other constituent elements. Other elements constituting the active metal species of the high-temperature denitration catalyst 220 include, for example, a group of elements from Group 5 to Group 11 of the periodic table (for example, vanadium (V), chromium (Cr), manganese (Mn), One or more elements selected from iron (Fe), cobalt (Co), and copper (Cu).

低温脱硝触媒２２２は、担体と、担体に担持された活性金属種とを含んで構成され、高温脱硝触媒２２０よりも活性温度が低い。低温脱硝触媒２２２の活性金属種は、周期表の第５属から第１１属の元素の群（例えば、バナジウム（Ｖ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、鉄（Ｆｅ）、コバルト（Ｃｏ）、銅（Ｃｕ））から選択される１または複数の元素を含んで構成される。本実施形態において、低温脱硝触媒２２２は、酸化チタンを担体とし、酸化バナジウムを主成分とし酸化タングステンを副成分とした活性金属種で構成される。なお、低温脱硝触媒２２２の活性金属種は、上記複数の元素以外の他の元素を含んでもよいが、複数の元素の含有量が、当該低温脱硝触媒２２２の活性金属種を構成する他の元素よりも多い必要がある。低温脱硝触媒２２２の活性金属種を構成する他の元素は、例えば、モリブデンやタングステンである。   The low-temperature denitration catalyst 222 includes a carrier and an active metal species supported on the carrier, and has an activation temperature lower than that of the high-temperature denitration catalyst 220. The active metal species of the low-temperature denitration catalyst 222 is a group of elements from Group 5 to Group 11 of the periodic table (for example, vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co ) And copper (Cu)). In this embodiment, the low-temperature denitration catalyst 222 is composed of an active metal species having titanium oxide as a carrier, vanadium oxide as a main component, and tungsten oxide as a subcomponent. The active metal species of the low-temperature denitration catalyst 222 may include elements other than the plurality of elements, but the content of the plurality of elements is another element constituting the active metal species of the low-temperature denitration catalyst 222. Need more. Other elements constituting the active metal species of the low-temperature denitration catalyst 222 are, for example, molybdenum and tungsten.

つまり、高温脱硝触媒２２０および低温脱硝触媒２２２において、活性金属種を構成する元素は、周期表の第５属から第１１属の元素の群（例えば、バナジウム（Ｖ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、鉄（Ｆｅ）、コバルト（Ｃｏ）、銅（Ｃｕ）、モリブデン（Ｍｏ）およびタングステン（Ｗ））から選択される１または複数の元素で構成されるが、その組成比が高温脱硝触媒２２０と、低温脱硝触媒２２２とで異なる。上述したように、高温脱硝触媒２２０は、活性金属種のうち、モリブデンやタングステンの含有量が他の元素よりも多く、低温脱硝触媒２２２は、活性金属種のうち、バナジウム、クロム、マンガン、鉄、コバルト、銅の含有量が、モリブデンやタングステンよりも多い。   That is, in the high-temperature denitration catalyst 220 and the low-temperature denitration catalyst 222, the elements constituting the active metal species are groups of elements from Group 5 to Group 11 of the periodic table (for example, vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), molybdenum (Mo), and tungsten (W)). The catalyst 220 and the low temperature denitration catalyst 222 are different. As described above, the high-temperature denitration catalyst 220 has a higher content of molybdenum and tungsten than other elements among the active metal species, and the low-temperature denitration catalyst 222 includes vanadium, chromium, manganese, iron among the active metal species. There is more content of cobalt and copper than molybdenum and tungsten.

図２は、高温脱硝触媒２２０と、低温脱硝触媒２２２の温度による脱硝率変化を説明するための図である。図２に示すように、低温脱硝触媒２２２（図２中、実線で示す）は、２００℃において、脱硝率（還元率）が２５％であり、２００℃から３００℃まで温度が上昇するにしたがって、脱硝率が向上し、３００℃では脱硝率が９０％以上となる。そして、低温脱硝触媒２２２は、３００℃から３８０℃程度の温度範囲であると、脱硝率を９０％から９９％に維持することができる。しかし、低温脱硝触媒２２２は、３８０℃以上となると、脱硝の反応速度が、アンモニア（還元剤）の酸化の反応速度を下回るため、脱硝率が急激に低下してしまう。   FIG. 2 is a diagram for explaining a change in the denitration rate depending on the temperatures of the high-temperature denitration catalyst 220 and the low-temperature denitration catalyst 222. As shown in FIG. 2, the low-temperature denitration catalyst 222 (shown by a solid line in FIG. 2) has a denitration rate (reduction rate) of 25% at 200 ° C. As the temperature increases from 200 ° C. to 300 ° C. The denitration rate is improved, and at 300 ° C., the denitration rate is 90% or more. The low-temperature denitration catalyst 222 can maintain the denitration rate from 90% to 99% in the temperature range of about 300 ° C. to 380 ° C. However, when the temperature of the low-temperature denitration catalyst 222 is 380 ° C. or higher, the denitration reaction rate is lower than the oxidation reaction rate of ammonia (reducing agent), and the denitration rate is drastically reduced.

一方、高温脱硝触媒２２０は、（図２中、破線で示す）は、２６０℃程度において、脱硝率（還元率）が２５％であり、２６０℃から３１０℃まで温度が上昇するにしたがって、脱硝率が向上し、３１０℃では脱硝率が７０％以上となる。そして、高温脱硝触媒２２０は、３１０℃から４３０℃程度の温度範囲であると、脱硝率を７０％から７８％に維持することができる。   On the other hand, the high-temperature denitration catalyst 220 (shown by a broken line in FIG. 2) has a denitration rate (reduction rate) of about 25% at about 260 ° C. As the temperature rises from 260 ° C. to 310 ° C., denitration is performed. The rate is improved, and the denitration rate becomes 70% or more at 310 ° C. The high-temperature denitration catalyst 220 can maintain the denitration rate from 70% to 78% in the temperature range of about 310 ° C. to 430 ° C.

高温脱硝触媒２２０は、４００℃未満では、低温脱硝触媒２２２と比較して脱硝率は低い。しかし、高温脱硝触媒２２０は、４００℃以上であっても、アンモニア（還元剤）の酸化の反応速度が、脱硝の反応速度を急激に上回ることがなく、脱硝率が急激に低下することはない。したがって、高温脱硝触媒２２０は、４００℃以上であっても、低温脱硝触媒２２２と比較して、高い脱硝率を維持することが可能となる。   The high-temperature denitration catalyst 220 has a denitration rate lower than 400 ° C. compared to the low-temperature denitration catalyst 222. However, even when the high-temperature denitration catalyst 220 is 400 ° C. or higher, the oxidation rate of ammonia (reducing agent) does not rapidly exceed the denitration reaction rate, and the denitration rate does not drop rapidly. . Therefore, the high-temperature denitration catalyst 220 can maintain a higher denitration rate than the low-temperature denitration catalyst 222 even at 400 ° C. or higher.

そこで、本実施形態では、脱硝装置２００が、温度によって脱硝特性が異なる高温脱硝触媒２２０および低温脱硝触媒２２２の双方を設置することで、排気ガスＸ１から効率よくＮＯｘを除去することを可能としている。   Therefore, in the present embodiment, the NOx removal apparatus 200 can efficiently remove NOx from the exhaust gas X1 by installing both the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 having different denitration characteristics depending on the temperature. .

なお、ここで、高温脱硝触媒２２０、および、低温脱硝触媒２２２は、ハニカム形状に形成されているため、高温脱硝触媒２２０、低温脱硝触媒２２２の温度は、高温脱硝触媒２２０、低温脱硝触媒２２２を流通する排気ガスの温度と実質的に同一とみなすことができる。   Here, since the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 are formed in a honeycomb shape, the temperature of the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 is the same as that of the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222. It can be regarded as substantially the same as the temperature of the exhaust gas that circulates.

図１に戻って説明すると、温度測定部２３２は、上流側温度センサ２３２ａと、下流側温度センサ２３２ｂとを含んで構成される。上流側温度センサ２３２ａは、排気ライン２０２におけるエンジン１１０と高温脱硝触媒２２０の間を流通する排気ガスＸ１の温度（上流側温度Ｔｕ）を測定する。下流側温度センサ２３２ｂは、排気ライン２０２におけるタービン２１２と低温脱硝触媒２２２との間を流通する排気ガスＸ２の温度（下流側温度Ｔｄ）を測定する。なお、排気ガスＸ２は、タービン２１２の下流側の排気ガスであるため、すなわち、タービン２１２が仕事をすることによって熱を消費するため、排気ガスＸ１よりも低温となっている。   Returning to FIG. 1, the temperature measurement unit 232 includes an upstream temperature sensor 232a and a downstream temperature sensor 232b. The upstream temperature sensor 232a measures the temperature (upstream temperature Tu) of the exhaust gas X1 flowing between the engine 110 and the high temperature denitration catalyst 220 in the exhaust line 202. The downstream temperature sensor 232b measures the temperature (downstream temperature Td) of the exhaust gas X2 flowing between the turbine 212 and the low-temperature denitration catalyst 222 in the exhaust line 202. Note that the exhaust gas X2 is exhaust gas on the downstream side of the turbine 212, that is, because heat is consumed by the work of the turbine 212, the temperature is lower than that of the exhaust gas X1.

還元剤導入部２３４は、後述する還元剤調整部２３６によって制御され、排気ライン２０２における、高温脱硝触媒２２０の上流側（排気ライン２０２におけるエンジン１１０と高温脱硝触媒２２０の間）、および、低温脱硝触媒２２２の上流側（排気ライン２０２におけるタービン２１２と低温脱硝触媒２２２との間）のいずれにも独立して還元剤（ここでは、還元剤の前駆体として尿素水）を導入（噴霧）可能である。   The reducing agent introduction unit 234 is controlled by a reducing agent adjusting unit 236, which will be described later, and upstream of the high temperature denitration catalyst 220 in the exhaust line 202 (between the engine 110 and the high temperature denitration catalyst 220 in the exhaust line 202) and low temperature denitration. A reducing agent (here, urea water as a reducing agent precursor) can be introduced (sprayed) independently of any of the upstream side of the catalyst 222 (between the turbine 212 and the low-temperature denitration catalyst 222 in the exhaust line 202). is there.

還元剤調整部２３６は、温度測定部２３２が測定した排気ガスＸ１、Ｘ２の温度に基づき、還元剤導入部２３４を制御して、高温脱硝触媒２２０の上流側、および、低温脱硝触媒２２２の上流側のいずれか一方または双方に還元剤を導入させる。以下に、還元剤調整部２３６による還元剤導入部２３４の制御（脱硝方法）について詳述する。   The reducing agent adjusting unit 236 controls the reducing agent introducing unit 234 based on the temperatures of the exhaust gases X1 and X2 measured by the temperature measuring unit 232, and upstream of the high temperature denitration catalyst 220 and upstream of the low temperature denitration catalyst 222. A reducing agent is introduced on either or both sides. Hereinafter, the control (denitration method) of the reducing agent introducing unit 234 by the reducing agent adjusting unit 236 will be described in detail.

（脱硝方法）
本実施形態にかかる脱硝方法では、高温脱硝触媒２２０とタービン２１２との間を流通する排気ガスＸ１の温度（上流側温度Ｔｕ）と、タービン２１２と低温脱硝触媒２２２との間を流通する排気ガスＸ２の温度（下流側温度Ｔｄ）とに基づいて、高温脱硝触媒２２０の上流側や低温脱硝触媒２２２の上流側への還元剤の導入を制御する。 (Denitration method)
In the denitration method according to the present embodiment, the temperature of the exhaust gas X1 (upstream temperature Tu) flowing between the high temperature denitration catalyst 220 and the turbine 212 and the exhaust gas flowing between the turbine 212 and the low temperature denitration catalyst 222. Based on the X2 temperature (downstream temperature Td), the introduction of the reducing agent to the upstream side of the high temperature denitration catalyst 220 and the upstream side of the low temperature denitration catalyst 222 is controlled.

下記表１および図３を参照して具体的に説明する。図３は、脱硝装置２００を用いた脱硝方法の処理の流れを説明するための図である。なお、表１中において、還元剤導入部２３４が還元剤を導入している状態を○印で示し、還元剤を導入しない状態を×印で示す。

Figure 2014043819
This will be specifically described with reference to Table 1 and FIG. FIG. 3 is a view for explaining the processing flow of the denitration method using the denitration apparatus 200. In Table 1, the state in which the reducing agent introduction unit 234 introduces the reducing agent is indicated by ◯, and the state in which the reducing agent is not introduced is indicated by X.
Figure 2014043819

上記図２に示したように、脱硝率の最大値は、低温脱硝触媒２２２の方が高温脱硝触媒２２０よりも高いため、低温脱硝触媒２２２を優先的に利用する。具体的に説明すると、下流側温度Ｔｄが、低温脱硝触媒２２２において、温度上昇に伴い脱硝率が９０％以上となる温度Ｔ１（例えば、３００℃。以下、温度上昇に伴い脱硝率が９０％以上となる温度Ｔ１を、単に、低温脱硝触媒２２２の上昇開始温度Ｔ１と称する）以上であれば、低温脱硝触媒２２２を優先的に利用する、すなわち、低温脱硝触媒２２２の上流側に還元剤を導入する。つまり、図３（ａ）に示すように、上流側温度Ｔｕ（排気ガスＸ１の温度）にかかわらず、すなわち、排気ガスＸ１の温度が、上昇開始温度Ｔ１未満であっても、上昇開始温度Ｔ１以上低下開始温度Ｔ２未満であっても、低下開始温度Ｔ２以上であっても、下流側温度Ｔｄ（排気ガスＸ２の温度）が上昇開始温度Ｔ１以上であれば、低温脱硝触媒２２２を優先的に利用する。   As shown in FIG. 2, the maximum value of the denitration rate is higher for the low-temperature denitration catalyst 222 than for the high-temperature denitration catalyst 220, so the low-temperature denitration catalyst 222 is used preferentially. More specifically, the downstream side temperature Td is a temperature T1 at which the denitration rate becomes 90% or more as the temperature rises in the low-temperature denitration catalyst 222 (for example, 300 ° C., hereinafter, the denitration rate becomes 90% or more as the temperature rises). If the temperature T1 is simply referred to as the rising start temperature T1 of the low-temperature denitration catalyst 222), the low-temperature denitration catalyst 222 is used preferentially, that is, a reducing agent is introduced upstream of the low-temperature denitration catalyst 222. To do. That is, as shown in FIG. 3A, regardless of the upstream temperature Tu (the temperature of the exhaust gas X1), that is, even if the temperature of the exhaust gas X1 is lower than the rise start temperature T1, the rise start temperature T1. If the downstream temperature Td (temperature of the exhaust gas X2) is equal to or higher than the rising start temperature T1, whether it is lower than the lowering start temperature T2 or higher than the lowering start temperature T2, the low-temperature denitration catalyst 222 is given priority. Use.

下流側温度Ｔｄが、低温脱硝触媒２２２の上昇開始温度（第１の閾値）Ｔ１以上であれば、脱硝率が９０％以上に維持される低温脱硝触媒２２２のみを利用してＮＯｘを還元することで、排気ガスから効率よくＮＯｘを除去することが可能となる。   If the downstream temperature Td is equal to or higher than the rising start temperature (first threshold value) T1 of the low-temperature denitration catalyst 222, NOx is reduced using only the low-temperature denitration catalyst 222 whose denitration rate is maintained at 90% or more. Thus, NOx can be efficiently removed from the exhaust gas.

一方、下流側温度Ｔｄが上昇開始温度Ｔ１未満である場合、図２に示すように、低温脱硝触媒２２２の脱硝率が急激に低下するため、低温脱硝触媒２２２を利用したとしても所望する脱硝率を得ることが難しい。そこで、下流側温度Ｔｄが上昇開始温度Ｔ１未満である場合、脱硝率の最大値は低温脱硝触媒２２２と比較して低いものの、７０％程度の脱硝率を有する高温脱硝触媒２２０を利用する。   On the other hand, when the downstream temperature Td is lower than the rising start temperature T1, as shown in FIG. 2, the denitration rate of the low-temperature denitration catalyst 222 is drastically lowered. Therefore, even if the low-temperature denitration catalyst 222 is used, a desired denitration rate is obtained. Difficult to get. Therefore, when the downstream temperature Td is lower than the rising start temperature T1, the high temperature denitration catalyst 220 having a denitration rate of about 70% is used although the maximum value of the denitration rate is lower than that of the low temperature denitration catalyst 222.

具体的に説明すると、下流側温度Ｔｄが上昇開始温度Ｔ１未満である場合、上流側温度Ｔｕが、高温脱硝触媒２２０において、温度上昇に伴い脱硝率が７０％未満となる温度Ｔ２（例えば、４００℃。以下、温度上昇に伴い脱硝率が７０％未満となる温度Ｔ２を、単に、高温脱硝触媒２２０の低下開始温度Ｔ２と称する）未満であれば、高温脱硝触媒２２０のみを利用する、すなわち、高温脱硝触媒２２０の上流側に還元剤を導入する。つまり、図３（ｂ）に示すように、下流側温度Ｔｄ（排気ガスＸ２の温度）が上昇開始温度Ｔ１未満の場合、上流側温度Ｔｕ（排気ガスＸ１の温度）が低下開始温度Ｔ２未満であれば、高温脱硝触媒２２０を利用する。   More specifically, when the downstream temperature Td is lower than the start temperature T1, the upstream temperature Tu is a temperature T2 at which the denitration rate becomes less than 70% as the temperature rises in the high temperature denitration catalyst 220 (for example, 400 Hereinafter, if the temperature T2 at which the denitration rate becomes less than 70% with temperature rise is simply referred to as the decrease start temperature T2 of the high temperature denitration catalyst 220), only the high temperature denitration catalyst 220 is used. A reducing agent is introduced upstream of the high temperature denitration catalyst 220. That is, as shown in FIG. 3B, when the downstream temperature Td (temperature of the exhaust gas X2) is lower than the rise start temperature T1, the upstream temperature Tu (temperature of the exhaust gas X1) is lower than the fall start temperature T2. If there is, the high temperature denitration catalyst 220 is used.

下流側温度Ｔｄの温度が低温脱硝触媒２２２の上昇開始温度Ｔ１未満である場合、上流側温度Ｔｕが高温脱硝触媒２２０の低下開始温度Ｔ２未満であれば、脱硝率が低い低温脱硝触媒２２２を利用せず、脱硝率が７０％以上に維持される高温脱硝触媒２２０のみを利用してＮＯｘを還元することで、排気ガスから効率よくＮＯｘを除去することが可能となる。   When the temperature of the downstream temperature Td is lower than the rise start temperature T1 of the low temperature denitration catalyst 222, the low temperature denitration catalyst 222 having a low denitration rate is used if the upstream temperature Tu is lower than the decrease start temperature T2 of the high temperature denitration catalyst 220. Without reducing NOx using only the high-temperature denitration catalyst 220 whose denitration rate is maintained at 70% or higher, NOx can be efficiently removed from the exhaust gas.

一方、下流側温度Ｔｄが上昇開始温度Ｔ１未満であって、上流側温度Ｔｕが低下開始温度Ｔ２以上である場合、図２に示すように、高温脱硝触媒２２０の脱硝率が低下するため、高温脱硝触媒２２０のみを利用したとしても所望する脱硝率を得ることができない。そこで、下流側温度Ｔｄが上昇開始温度Ｔ１未満であり、上流側温度Ｔｕが低下開始温度Ｔ２以上である場合、高温脱硝触媒２２０および低温脱硝触媒２２２を利用する、すなわち、高温脱硝触媒２２０の上流側および低温脱硝触媒２２２の上流側に還元剤を導入する。つまり、図３（ｃ）に示すように、下流側温度Ｔｄ（排気ガスＸ２の温度）が上昇開始温度Ｔ１未満の場合、上流側温度Ｔｕ（排気ガスＸ１の温度）が低下開始温度Ｔ２以上であれば、高温脱硝触媒２２０および低温脱硝触媒２２２を利用する。   On the other hand, when the downstream temperature Td is lower than the increase start temperature T1 and the upstream temperature Tu is equal to or higher than the decrease start temperature T2, the denitration rate of the high temperature denitration catalyst 220 decreases as shown in FIG. Even if only the denitration catalyst 220 is used, a desired denitration rate cannot be obtained. Therefore, when the downstream temperature Td is lower than the rise start temperature T1 and the upstream temperature Tu is equal to or higher than the fall start temperature T2, the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 are used, that is, upstream of the high temperature denitration catalyst 220. A reducing agent is introduced on the side and upstream of the low-temperature denitration catalyst 222. That is, as shown in FIG. 3C, when the downstream temperature Td (temperature of the exhaust gas X2) is lower than the increase start temperature T1, the upstream temperature Tu (temperature of the exhaust gas X1) is equal to or higher than the decrease start temperature T2. If present, the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 are used.

下流側温度Ｔｄが低温脱硝触媒２２２の上昇開始温度Ｔ１未満であり、かつ、上流側温度Ｔｕが高温脱硝触媒２２０の低下開始温度Ｔ２以上である場合、高温脱硝触媒２２０の脱硝率の低下がみられるため、高温脱硝触媒２２０に加えて、低温脱硝触媒２２２を利用する。こうすることで、高温脱硝触媒２２０、低温脱硝触媒２２２のトータルの脱硝率で、所望する脱硝率を達成することができる。   When the downstream temperature Td is lower than the rise start temperature T1 of the low temperature denitration catalyst 222 and the upstream temperature Tu is equal to or higher than the fall start temperature T2 of the high temperature denitration catalyst 220, the denitration rate of the high temperature denitration catalyst 220 is reduced. Therefore, the low temperature denitration catalyst 222 is used in addition to the high temperature denitration catalyst 220. By doing so, the desired denitration rate can be achieved with the total denitration rate of the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222.

このような高温脱硝触媒２２０および低温脱硝触媒２２２の制御を、表１を参照して各触媒個々にみると、低温脱硝触媒２２２に関しては、下流側温度Ｔｄ≧上昇開始温度Ｔ１である場合、または、上流側温度Ｔｕ≧低下開始温度Ｔ２の場合に還元剤が導入され、高温脱硝触媒２２０は、上流側温度Ｔｕに拘わらず、下流側温度Ｔｄ<上昇開始温度Ｔ１の場合に還元剤が導入されていることが理解できる。したがって、低温脱硝触媒２２２と高温脱硝触媒２２０とを下流側温度Ｔｄおよび上流側温度Ｔｕによってそれぞれ独立して個々に制御でき、下流側温度Ｔｄ≧上昇開始温度Ｔ１である場合、または、上流側温度Ｔｕ≧低下開始温度Ｔ２の場合に低温脱硝触媒２２２に還元剤を導入し、下流側温度Ｔｄ<上昇開始温度Ｔ１の場合に高温脱硝触媒２２０に還元剤を導入すればよいことが分かる。以下、このような制御手順による脱硝方法の処理の流れを説明する。   When the control of the high-temperature denitration catalyst 220 and the low-temperature denitration catalyst 222 is viewed for each catalyst with reference to Table 1, with respect to the low-temperature denitration catalyst 222, when the downstream temperature Td ≧ the rising start temperature T1, or The reducing agent is introduced when the upstream temperature Tu ≧ the reduction start temperature T2, and the high temperature denitration catalyst 220 is introduced with the reducing agent when the downstream temperature Td <the rising start temperature T1 regardless of the upstream temperature Tu. I can understand that. Therefore, the low-temperature denitration catalyst 222 and the high-temperature denitration catalyst 220 can be individually controlled individually by the downstream temperature Td and the upstream temperature Tu, and when the downstream temperature Td ≧ the rising start temperature T1, or the upstream temperature It can be seen that a reducing agent may be introduced into the low-temperature denitration catalyst 222 when Tu ≧ decrease start temperature T2, and a reducing agent may be introduced into the high-temperature denitration catalyst 220 when downstream temperature Td <rise start temperature T1. Hereinafter, the processing flow of the denitration method according to such a control procedure will be described.

図４は、脱硝装置２００を用いた脱硝方法の処理の流れを説明するためのフローチャートである。   FIG. 4 is a flowchart for explaining the flow of processing of the denitration method using the denitration apparatus 200.

図４に示すように、まず、還元剤調整部２３６は、下流側温度Ｔｄが上昇開始温度Ｔ１以上であるか否か、または、上流側温度Ｔｕが低下開始温度Ｔ２以上であるか否かを判定する（Ｓ３００）。   As shown in FIG. 4, first, the reducing agent adjustment unit 236 determines whether or not the downstream temperature Td is equal to or higher than the increase start temperature T1, or whether or not the upstream temperature Tu is equal to or higher than the decrease start temperature T2. Determine (S300).

下流側温度Ｔｄが上昇開始温度Ｔ１以上である場合、または、上流側温度Ｔｕが低下開始温度Ｔ２以上である場合（Ｓ３００におけるＹＥＳ）、還元剤導入部２３４が低温脱硝触媒２２２の上流側に還元剤を導入しているか否か、すなわち、低温脱硝触媒２２２がＮＯｘを還元しているか否かを判定する（Ｓ３０２）。   When the downstream temperature Td is equal to or higher than the rising start temperature T1 or when the upstream temperature Tu is equal to or higher than the lowering start temperature T2 (YES in S300), the reducing agent introduction unit 234 reduces to the upstream side of the low-temperature denitration catalyst 222. It is determined whether or not the agent is introduced, that is, whether or not the low-temperature denitration catalyst 222 is reducing NOx (S302).

還元剤導入部２３４が低温脱硝触媒２２２の上流側に還元剤を導入していないと判定すると（Ｓ３０２におけるＮＯ）、還元剤調整部２３６は、還元剤導入部２３４を制御して、低温脱硝触媒２２２の上流側への還元剤の導入を開始させる（Ｓ３０４）。つまり、下流側温度Ｔｄの温度が低温脱硝触媒２２２の上昇開始温度Ｔ１以上であるか、上流側温度Ｔｕの温度が高温脱硝触媒２２０の低下開始温度Ｔ２以上である場合、還元剤調整部２３６は、還元剤導入部２３４を制御して、低温脱硝触媒２２２の上流側に還元剤を導入させる。   If it is determined that the reducing agent introduction unit 234 has not introduced the reducing agent upstream of the low temperature denitration catalyst 222 (NO in S302), the reducing agent adjustment unit 236 controls the reducing agent introduction unit 234 to control the low temperature denitration catalyst. Introduction of the reducing agent to the upstream side of 222 is started (S304). In other words, when the temperature of the downstream temperature Td is equal to or higher than the rise start temperature T1 of the low temperature denitration catalyst 222 or the temperature of the upstream temperature Tu is equal to or higher than the decrease start temperature T2 of the high temperature denitration catalyst 220, the reducing agent adjusting unit 236 Then, the reducing agent introduction unit 234 is controlled to introduce the reducing agent upstream of the low-temperature denitration catalyst 222.

なお、還元剤導入部２３４が低温脱硝触媒２２２の上流側に還元剤を導入していると判定すると（Ｓ３０２におけるＹＥＳ）、還元剤調整部２３６は、低温脱硝触媒２２２の上流側への還元剤の導入を維持させ、後述するステップＳ３１０へ処理を移す。   If it is determined that the reducing agent introduction unit 234 has introduced the reducing agent upstream of the low temperature denitration catalyst 222 (YES in S302), the reducing agent adjustment unit 236 returns the reducing agent upstream of the low temperature denitration catalyst 222. Is maintained, and the process proceeds to step S310 to be described later.

一方、下流側温度Ｔｄが上昇開始温度Ｔ１以上ではなく、かつ、上流側温度Ｔｕが低下開始温度Ｔ２以上ではない場合（Ｓ３００におけるＮＯ）、還元剤導入部２３４が低温脱硝触媒２２２の上流側に還元剤を導入しているか否か、すなわち、低温脱硝触媒２２２がＮＯｘを還元しているか否かを判定する（Ｓ３０６）。   On the other hand, when the downstream temperature Td is not equal to or higher than the increase start temperature T1 and the upstream temperature Tu is not equal to or greater than the decrease start temperature T2 (NO in S300), the reducing agent introduction unit 234 is located upstream of the low temperature denitration catalyst 222. It is determined whether or not a reducing agent is introduced, that is, whether or not the low-temperature denitration catalyst 222 is reducing NOx (S306).

還元剤導入部２３４が低温脱硝触媒２２２の上流側に還元剤を導入していると判定すると（Ｓ３０６におけるＹＥＳ）、還元剤調整部２３６は、還元剤導入部２３４を制御して、低温脱硝触媒２２２の上流側への還元剤の導入を停止させる（Ｓ３０８）。   If it is determined that the reducing agent introduction unit 234 has introduced the reducing agent upstream of the low temperature denitration catalyst 222 (YES in S306), the reducing agent adjustment unit 236 controls the reducing agent introduction unit 234 to control the low temperature denitration catalyst. The introduction of the reducing agent to the upstream side of 222 is stopped (S308).

なお、還元剤導入部２３４が低温脱硝触媒２２２の上流側に還元剤を導入していないと判定すると（Ｓ３０６におけるＮＯ）、還元剤調整部２３６は、還元剤導入部２３４による低温脱硝触媒２２２の上流側への還元剤の導入の停止状態を維持させ、後述するステップＳ３１０へ処理を移す。   If it is determined that the reducing agent introduction unit 234 has not introduced the reducing agent upstream of the low temperature denitration catalyst 222 (NO in S306), the reducing agent adjustment unit 236 uses the reducing agent introduction unit 234 of the low temperature denitration catalyst 222. The stop state of introduction of the reducing agent to the upstream side is maintained, and the process proceeds to step S310 described later.

そして、還元剤調整部２３６は、下流側温度Ｔｄが上昇開始温度Ｔ１未満であるか否かを判定する（Ｓ３１０）。   Then, the reducing agent adjustment unit 236 determines whether or not the downstream temperature Td is lower than the increase start temperature T1 (S310).

下流側温度Ｔｄが上昇開始温度Ｔ１未満である場合（Ｓ３１０におけるＹＥＳ）、還元剤調整部２３６は、還元剤導入部２３４が高温脱硝触媒２２０の上流側に還元剤を導入しているか否か、すなわち、高温脱硝触媒２２０がＮＯｘを還元しているか否かを判定する（Ｓ３１２）。   When the downstream temperature Td is lower than the rising start temperature T1 (YES in S310), the reducing agent adjusting unit 236 determines whether the reducing agent introduction unit 234 has introduced the reducing agent upstream of the high temperature denitration catalyst 220, That is, it is determined whether or not the high temperature denitration catalyst 220 is reducing NOx (S312).

還元剤導入部２３４が高温脱硝触媒２２０の上流側に還元剤を導入していないと判定すると（Ｓ３１２におけるＮＯ）、還元剤調整部２３６は、還元剤導入部２３４を制御して、高温脱硝触媒２２０の上流側への還元剤の導入を開始させる（Ｓ３１４）。つまり、下流側温度Ｔｄの温度が、低温脱硝触媒２２２の上昇開始温度Ｔ１未満であれば、還元剤調整部２３６は、還元剤導入部２３４を制御して、高温脱硝触媒２２０の上流側に還元剤を導入させる。   If it is determined that the reducing agent introduction unit 234 has not introduced the reducing agent upstream of the high temperature denitration catalyst 220 (NO in S312), the reducing agent adjustment unit 236 controls the reducing agent introduction unit 234 to control the high temperature denitration catalyst. Introduction of the reducing agent to the upstream side of 220 is started (S314). That is, when the temperature of the downstream temperature Td is lower than the rising start temperature T1 of the low-temperature denitration catalyst 222, the reducing agent adjusting unit 236 controls the reducing agent introduction unit 234 to reduce the temperature to the upstream side of the high temperature denitration catalyst 220. The agent is introduced.

なお、還元剤導入部２３４が高温脱硝触媒２２０の上流側に還元剤を導入していると判定すると（Ｓ３１２におけるＹＥＳ）、還元剤調整部２３６は、高温脱硝触媒２２０の上流側への還元剤の導入を維持させ、ステップＳ３００へ処理を戻す。   If it is determined that the reducing agent introduction unit 234 has introduced the reducing agent upstream of the high temperature denitration catalyst 220 (YES in S312), the reducing agent adjustment unit 236 returns the reducing agent to the upstream side of the high temperature denitration catalyst 220. Is maintained, and the process returns to step S300.

一方、下流側温度Ｔｄが上昇開始温度Ｔ１未満でない場合（Ｓ３１０におけるＮＯ）、還元剤調整部２３６は、還元剤導入部２３４が高温脱硝触媒２２０の上流側に還元剤を導入しているか否か、すなわち、高温脱硝触媒２２０がＮＯｘを還元しているか否かを判定する（Ｓ３１６）。   On the other hand, when the downstream temperature Td is not lower than the rise start temperature T1 (NO in S310), the reducing agent adjusting unit 236 determines whether the reducing agent introduction unit 234 has introduced the reducing agent upstream of the high temperature denitration catalyst 220. That is, it is determined whether or not the high temperature denitration catalyst 220 is reducing NOx (S316).

還元剤導入部２３４が高温脱硝触媒２２０の上流側に還元剤を導入していると判定すると（Ｓ３１６におけるＹＥＳ）、還元剤調整部２３６は、還元剤導入部２３４を制御して、高温脱硝触媒２２０の上流側への還元剤の導入を停止させる（Ｓ３１８）。つまり、下流側温度Ｔｄの温度が、低温脱硝触媒２２２の上昇開始温度Ｔ１以上であれば、還元剤調整部２３６は、還元剤導入部２３４を制御して、高温脱硝触媒２２０の上流側への還元剤の導入を停止させる。   If it is determined that the reducing agent introduction unit 234 has introduced the reducing agent upstream of the high temperature denitration catalyst 220 (YES in S316), the reducing agent adjustment unit 236 controls the reducing agent introduction unit 234 to control the high temperature denitration catalyst. The introduction of the reducing agent to the upstream side of 220 is stopped (S318). That is, if the temperature of the downstream side temperature Td is equal to or higher than the rising start temperature T1 of the low temperature denitration catalyst 222, the reducing agent adjusting unit 236 controls the reducing agent introduction unit 234 to the upstream side of the high temperature denitration catalyst 220. Stop introducing the reducing agent.

なお、還元剤導入部２３４が高温脱硝触媒２２０の上流側に還元剤を導入していないと判定すると（Ｓ３１６におけるＮＯ）、還元剤調整部２３６は、還元剤導入部２３４による高温脱硝触媒２２０の上流側への還元剤の導入の停止状態を維持させ、ステップＳ３００へ処理を戻す。   When it is determined that the reducing agent introduction unit 234 has not introduced the reducing agent upstream of the high temperature denitration catalyst 220 (NO in S316), the reducing agent adjustment unit 236 uses the reducing agent introduction unit 234 to perform the high temperature denitration catalyst 220. The state of stopping the introduction of the reducing agent to the upstream side is maintained, and the process returns to step S300.

以上説明したように、本実施形態にかかる脱硝装置２００およびこれを用いた脱硝方法によれば、活性温度が異なる２種類の脱硝触媒（高温脱硝触媒２２０、低温脱硝触媒２２２）を適切な位置（高温脱硝触媒２２０はタービン２１２の上流側、低温脱硝触媒２２２はタービン２１２の下流側）に設置し、それぞれの温度に基づいて適切に還元剤を導入することで、排気ガスから効率よくＮＯｘを除去することが可能となる。   As described above, according to the denitration apparatus 200 and the denitration method using the same according to the present embodiment, two types of denitration catalysts (high temperature denitration catalyst 220 and low temperature denitration catalyst 222) having different activation temperatures are placed at appropriate positions ( The high temperature denitration catalyst 220 is installed upstream of the turbine 212 and the low temperature denitration catalyst 222 is downstream of the turbine 212), and NOx is efficiently removed from the exhaust gas by appropriately introducing a reducing agent based on the respective temperatures. It becomes possible to do.

以上、添付図面を参照しながら本発明の好適な実施形態について説明したが、本発明はかかる実施形態に限定されないことは言うまでもない。当業者であれば、特許請求の範囲に記載された範疇において、各種の変更例または修正例に想到し得ることは明らかであり、それらについても当然に本発明の技術的範囲に属するものと了解される。   As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

例えば、上述した実施形態において、高温脱硝触媒２２０および低温脱硝触媒２２２は、担体として酸化チタンを利用する構成を例に挙げて説明したが、担体は酸化チタンに限定されず、酸化チタン、酸化アルミニウム（アルミナ）、二酸化ケイ素（シリカ）、二酸化ジルコニウム（ジルコニア）、酸化セリウム（セリア）の群から選択される１または複数で構成されてもよい。   For example, in the above-described embodiment, the high-temperature denitration catalyst 220 and the low-temperature denitration catalyst 222 have been described by taking as an example a configuration using titanium oxide as a carrier, but the carrier is not limited to titanium oxide, and titanium oxide, aluminum oxide (Alumina), silicon dioxide (silica), zirconium dioxide (zirconia), or one or more selected from the group of cerium oxide (ceria).

また、上述した実施形態において、高温脱硝触媒２２０として、酸化チタンを担体とし、酸化タングステンを活性金属種として構成される触媒を例に挙げ、低温脱硝触媒２２２として酸化チタンを担体とし、酸化バナジウムを主成分とし酸化タングステンを副成分とした活性金属種で構成される触媒を例に挙げて説明した。したがって、高温脱硝触媒２２０、低温脱硝触媒２２２の温度による脱硝率変化は、図２に示すようになる。しかし、高温脱硝触媒２２０、低温脱硝触媒２２２の活性温度（温度による脱硝率変化）はこれに限定されない。つまり、低温脱硝触媒２２２の活性温度が高温脱硝触媒２２０の活性温度よりも低ければよく、すなわち、高温脱硝触媒２２０と低温脱硝触媒２２２との活性温度範囲が異なればよく、エンジン１１０の構成（排気ガスの温度）に応じて、高温脱硝触媒２２０、低温脱硝触媒２２２の活性金属種や活性金属種における元素の組成比を適宜変更することができる。   In the above-described embodiment, the high temperature denitration catalyst 220 is exemplified by a catalyst composed of titanium oxide as a carrier and tungsten oxide as an active metal species. The low temperature denitration catalyst 222 is composed of titanium oxide as a carrier and vanadium oxide. A catalyst composed of an active metal species having a main component and tungsten oxide as an auxiliary component has been described as an example. Accordingly, changes in the denitration rate depending on the temperatures of the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 are as shown in FIG. However, the activation temperatures of the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 (change in the denitration rate depending on the temperature) are not limited to this. In other words, the activation temperature of the low-temperature denitration catalyst 222 only needs to be lower than the activation temperature of the high-temperature denitration catalyst 220, that is, the activation temperature range of the high-temperature denitration catalyst 220 and the low-temperature denitration catalyst 222 only needs to be different. Depending on the gas temperature), the active metal species of the high-temperature denitration catalyst 220 and the low-temperature denitration catalyst 222 and the composition ratio of elements in the active metal species can be appropriately changed.

また、還元剤調整部２３６は、排気ガスＸ１、Ｘ２のＮＯｘ濃度を測定し、ＮＯｘ濃度に応じて、還元剤導入部２３４に還元剤を導入させてもよい。かかる構成により、排気ガス中のＮＯｘが多いときにそのＮＯｘを還元するために必要な量の尿素水を導入することが可能となる。また、排気ガス中のＮＯｘが少ないときに必要以上に尿素水を導入してしまい、高温脱硝触媒２２０、低温脱硝触媒２２２においてＮＨ３（アンモニア）が酸化されずに、外部に排出されてしまう事態を回避することができる。 Further, the reducing agent adjusting unit 236 may measure the NOx concentration of the exhaust gases X1 and X2, and may cause the reducing agent introducing unit 234 to introduce the reducing agent according to the NOx concentration. With such a configuration, it is possible to introduce an amount of urea water necessary for reducing NOx when the amount of NOx in the exhaust gas is large. Further, when NOx in the exhaust gas is small, urea water is introduced more than necessary, and NH 3 (ammonia) is not oxidized in the high temperature denitration catalyst 220 and the low temperature denitration catalyst 222 but is discharged outside. Can be avoided.

なお、本明細書の脱硝方法の各工程は、必ずしもフローチャートとして記載された順序に沿って時系列に処理する必要はなく、並列的あるいはサブルーチンによる処理を含んでもよい。   Note that each step of the denitration method of the present specification does not necessarily have to be processed in time series in the order described in the flowchart, and may include processing in parallel or by a subroutine.

本発明は、エンジンの排ガス中に含まれる窒素酸化物を、還元剤を用いて窒素に還元する脱硝装置、および、脱硝方法に利用することができる。   INDUSTRIAL APPLICABILITY The present invention can be used in a denitration apparatus and a denitration method that reduce nitrogen oxides contained in engine exhaust gas to nitrogen using a reducing agent.

１００ …脱硝システム
１１０ …エンジン
２００ …脱硝装置
２０２ …排気ライン
２１０ …過給機
２１２ …タービン
２１４ …圧縮機
２２０ …高温脱硝触媒（上流側脱硝触媒）
２２２ …低温脱硝触媒（下流側脱硝触媒）
２３２ …温度測定部
２３４ …還元剤導入部
２３６ …還元剤調整部 DESCRIPTION OF SYMBOLS 100 ... Denitration system 110 ... Engine 200 ... Denitration apparatus 202 ... Exhaust line 210 ... Supercharger 212 ... Turbine 214 ... Compressor 220 ... High temperature denitration catalyst (upstream denitration catalyst)
222 ... Low temperature denitration catalyst (downstream denitration catalyst)
232 ... Temperature measuring unit 234 ... Reducing agent introduction unit 236 ... Reducing agent adjusting unit

Claims (6)

エンジンから送出された排気ガスによって回転するタービン、および、該タービンの回転を利用して空気を圧縮し該エンジンに圧縮した空気を導入する圧縮機を有する過給機と、
前記タービンの上流側に設けられ、該上流側の排気ガスに含まれる窒素酸化物の還元を促進する上流側脱硝触媒と、
前記タービンの下流側に設けられ、該下流側の排気ガスに含まれる窒素酸化物の還元を促進する、前記上流側脱硝触媒よりも活性温度が低い下流側脱硝触媒と、
前記上流側脱硝触媒の上流側、および、前記下流側脱硝触媒の上流側に還元剤を導入する還元剤導入部と、
を備えたことを特徴とする脱硝装置。 A turbine that is rotated by exhaust gas delivered from an engine, and a supercharger that includes a compressor that compresses air by using the rotation of the turbine and introduces compressed air to the engine;
An upstream denitration catalyst that is provided upstream of the turbine and promotes reduction of nitrogen oxides contained in the exhaust gas on the upstream side;
A downstream denitration catalyst that is provided on the downstream side of the turbine and promotes reduction of nitrogen oxides contained in the exhaust gas on the downstream side and has an activation temperature lower than that of the upstream denitration catalyst;
A reducing agent introduction section for introducing a reducing agent to the upstream side of the upstream denitration catalyst and the upstream side of the downstream denitration catalyst;
A denitration apparatus comprising: 前記還元剤導入部は、前記上流側脱硝触媒の上流側、および、前記下流側脱硝触媒の上流側のいずれにも独立して還元剤を導入可能であり、
前記タービンと前記下流側脱硝触媒との間を流通する排気ガスの温度である下流側温度を測定する温度測定部と、
前記下流側温度が第１の閾値以上である場合、前記還元剤導入部を制御して、前記下流側脱硝触媒の上流側のみに還元剤を導入させる還元剤調整部と、
を備えたことを特徴とする請求項１に記載の脱硝装置。 The reducing agent introduction unit can introduce the reducing agent independently to both the upstream side of the upstream denitration catalyst and the upstream side of the downstream denitration catalyst,
A temperature measuring unit that measures a downstream temperature that is a temperature of exhaust gas flowing between the turbine and the downstream denitration catalyst;
When the downstream temperature is equal to or higher than a first threshold, the reducing agent introduction unit is controlled to introduce the reducing agent only upstream of the downstream denitration catalyst; and
The denitration apparatus according to claim 1, further comprising: 前記温度測定部は、前記下流側温度とともに、前記エンジンと前記上流側脱硝触媒との間を流通する排気ガスの温度である上流側温度を測定し、
前記還元剤調整部は、前記下流側温度が第１の閾値未満であり、前記上流側温度が第１の閾値より高い第２の閾値未満である場合、前記還元剤導入部を制御して、前記上流側脱硝触媒の上流側のみに還元剤を導入させることを特徴とする請求項２に記載の脱硝装置。 The temperature measuring unit measures an upstream temperature that is a temperature of exhaust gas flowing between the engine and the upstream denitration catalyst together with the downstream temperature,
The reducing agent adjusting unit controls the reducing agent introducing unit when the downstream temperature is lower than a first threshold and the upstream temperature is lower than a second threshold higher than the first threshold, The denitration apparatus according to claim 2, wherein the reducing agent is introduced only to the upstream side of the upstream denitration catalyst. 前記還元剤調整部は、前記下流側温度が第１の閾値未満であり、前記上流側温度が前記第２の閾値以上である場合、前記還元剤導入部を制御して、前記上流側脱硝触媒の上流側および前記下流側脱硝触媒の上流側に還元剤を導入させることを特徴とする請求項２または３に記載の脱硝装置。   The reducing agent adjusting unit controls the reducing agent introduction unit to control the upstream denitration catalyst when the downstream temperature is lower than a first threshold and the upstream temperature is equal to or higher than the second threshold. 4. The denitration apparatus according to claim 2, wherein a reducing agent is introduced upstream of the catalyst and upstream of the downstream denitration catalyst. 5. 前記上流側脱硝触媒は、モリブデン（Ｍｏ）およびタングステン（Ｗ）のいずれか一方または双方を含み、モリブデン（Ｍｏ）およびタングステン（Ｗ）のいずれか一方または双方の含有量が、該上流側脱硝触媒の活性金属種を構成する他の元素よりも多く、
前記下流側脱硝触媒は、周期表の第５属から第１１属の元素の群から選択される１または複数の元素を含むことを特徴とする請求項１から４のいずれか１項に記載の脱硝装置。 The upstream denitration catalyst includes one or both of molybdenum (Mo) and tungsten (W), and the content of either or both of molybdenum (Mo) and tungsten (W) is the upstream denitration catalyst. More than the other elements that make up the active metal species,
5. The downstream denitration catalyst includes one or a plurality of elements selected from the group of elements of Group 5 to Group 11 of the periodic table. 5. Denitration equipment. エンジンから送出された排気ガスによって回転するタービン、および、該タービンの回転を利用して空気を圧縮し該エンジンに圧縮した空気を導入する圧縮機を有する過給機と、該タービンの上流側に設けられ、該上流側の排気ガスに含まれる窒素酸化物の還元を促進する上流側脱硝触媒と、該タービンの下流側に設けられ、該下流側の排気ガスに含まれる窒素酸化物の還元を促進する、該上流側脱硝触媒よりも活性温度が低い下流側脱硝触媒とを用いた脱硝方法であって、
前記タービンと前記下流側脱硝触媒との間を流通する排気ガスの温度である下流側温度が第１の閾値以上である場合、前記下流側脱硝触媒の上流側のみに還元剤を導入し、
前記下流側温度が第１の閾値未満であり、前記エンジンと前記上流側脱硝触媒との間を流通する排気ガスの温度である上流側温度が該第１の閾値より高い第２の閾値未満である場合、前記上流側脱硝触媒の上流側のみに還元剤を導入し、
前記下流側温度が第１の閾値未満であり、前記上流側温度が前記第２の閾値以上である場合、前記上流側脱硝触媒の上流側および前記下流側脱硝触媒の上流側に還元剤を導入することを特徴とする脱硝方法。 A turbine that is rotated by exhaust gas delivered from an engine, a turbocharger having a compressor that compresses air by using the rotation of the turbine and introduces compressed air to the engine, and an upstream side of the turbine An upstream denitration catalyst that promotes reduction of nitrogen oxides contained in the upstream exhaust gas, and a nitrogen oxide contained in the downstream exhaust gas provided downstream of the turbine. A denitration method using a downstream denitration catalyst having a lower activation temperature than the upstream denitration catalyst,
When the downstream temperature that is the temperature of the exhaust gas flowing between the turbine and the downstream denitration catalyst is equal to or higher than the first threshold, a reducing agent is introduced only on the upstream side of the downstream denitration catalyst,
The downstream temperature is less than a first threshold, and the upstream temperature, which is the temperature of exhaust gas flowing between the engine and the upstream denitration catalyst, is less than a second threshold that is higher than the first threshold. In some cases, a reducing agent is introduced only upstream of the upstream denitration catalyst,
When the downstream temperature is lower than the first threshold and the upstream temperature is equal to or higher than the second threshold, a reducing agent is introduced to the upstream side of the upstream denitration catalyst and the upstream side of the downstream denitration catalyst. And a denitration method.
JP2012187215A 2012-08-28 2012-08-28 Denitration apparatus and denitration method Active JP6079056B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2012187215A JP6079056B2 (en) 2012-08-28 2012-08-28 Denitration apparatus and denitration method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2012187215A JP6079056B2 (en) 2012-08-28 2012-08-28 Denitration apparatus and denitration method

Publications (2)

Publication Number Publication Date
JP2014043819A true JP2014043819A (en) 2014-03-13
JP6079056B2 JP6079056B2 (en) 2017-02-15

Family

ID=50395261

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2012187215A Active JP6079056B2 (en) 2012-08-28 2012-08-28 Denitration apparatus and denitration method

Country Status (1)

Country Link
JP (1) JP6079056B2 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104950022A (en) * 2014-03-28 2015-09-30 日立造船株式会社 Denitrification rate measuring method and measuring device for engine
CN105289303A (en) * 2015-11-11 2016-02-03 华南理工大学 Eddy-flow atomization SCR denitration method and apparatus thereof
JP2017180157A (en) * 2016-03-29 2017-10-05 国立研究開発法人 海上・港湾・航空技術研究所 Denitration system
WO2017175651A1 (en) * 2016-04-08 2017-10-12 三井造船株式会社 Marine engine system and vessel
JP2020515759A (en) * 2017-03-30 2020-05-28 ジョンソン、マッセイ、パブリック、リミテッド、カンパニーＪｏｈｎｓｏｎ Ｍａｔｔｈｅｙ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ SCR with turbo and ASC/DOC proximal coupling system
KR20210132369A (en) * 2020-04-27 2021-11-04 한국조선해양 주식회사 Exhaust gas treatment apparatus for ship and ship having the same

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5559846A (en) * 1979-07-18 1980-05-06 Hitachi Zosen Corp Catalyst having activity at low temperature for exhaust smoke denitration
JPH06235319A (en) * 1993-02-05 1994-08-23 Yanmar Diesel Engine Co Ltd Internal combustion engine equipped with reduced type denitration catalyst
JPH10225641A (en) * 1997-02-14 1998-08-25 Osaka Gas Co Ltd Low temperature denitration catalyst and its production and low temperature denitration method
JPH10317950A (en) * 1997-03-19 1998-12-02 Toyota Motor Corp Fuel injection control device of direct injection type internal combustion engine
JP2003284927A (en) * 2002-03-28 2003-10-07 Hitachi Zosen Corp High temperature denitration catalyst
JP2004066070A (en) * 2002-08-05 2004-03-04 Mitsui Eng & Shipbuild Co Ltd Method of producing denitrification catalyst, denitrification catalyst, and denitrification system
US20110064632A1 (en) * 2009-09-14 2011-03-17 Ford Global Technologies, Llc Staged Catalyst System and Method of Using the Same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5559846A (en) * 1979-07-18 1980-05-06 Hitachi Zosen Corp Catalyst having activity at low temperature for exhaust smoke denitration
JPH06235319A (en) * 1993-02-05 1994-08-23 Yanmar Diesel Engine Co Ltd Internal combustion engine equipped with reduced type denitration catalyst
JPH10225641A (en) * 1997-02-14 1998-08-25 Osaka Gas Co Ltd Low temperature denitration catalyst and its production and low temperature denitration method
JPH10317950A (en) * 1997-03-19 1998-12-02 Toyota Motor Corp Fuel injection control device of direct injection type internal combustion engine
JP2003284927A (en) * 2002-03-28 2003-10-07 Hitachi Zosen Corp High temperature denitration catalyst
JP2004066070A (en) * 2002-08-05 2004-03-04 Mitsui Eng & Shipbuild Co Ltd Method of producing denitrification catalyst, denitrification catalyst, and denitrification system
US20110064632A1 (en) * 2009-09-14 2011-03-17 Ford Global Technologies, Llc Staged Catalyst System and Method of Using the Same

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104950022A (en) * 2014-03-28 2015-09-30 日立造船株式会社 Denitrification rate measuring method and measuring device for engine
KR20150112848A (en) * 2014-03-28 2015-10-07 히다치 조센 가부시키가이샤 Method and apparatus for measuring denitration ratio for an internal combustion engine
JP2015190356A (en) * 2014-03-28 2015-11-02 日立造船株式会社 Method and device for measuring nox removal efficiency for engine
CN104950022B (en) * 2014-03-28 2019-01-22 日立造船株式会社 Denitrification rate measuring method and measurement device for engine
KR102274546B1 (en) 2014-03-28 2021-07-06 히다치 조센 가부시키가이샤 Method and apparatus for measuring denitration ratio for an internal combustion engine
CN105289303A (en) * 2015-11-11 2016-02-03 华南理工大学 Eddy-flow atomization SCR denitration method and apparatus thereof
JP2017180157A (en) * 2016-03-29 2017-10-05 国立研究開発法人 海上・港湾・航空技術研究所 Denitration system
WO2017175651A1 (en) * 2016-04-08 2017-10-12 三井造船株式会社 Marine engine system and vessel
JP2020515759A (en) * 2017-03-30 2020-05-28 ジョンソン、マッセイ、パブリック、リミテッド、カンパニーＪｏｈｎｓｏｎ Ｍａｔｔｈｅｙ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ SCR with turbo and ASC/DOC proximal coupling system
KR20210132369A (en) * 2020-04-27 2021-11-04 한국조선해양 주식회사 Exhaust gas treatment apparatus for ship and ship having the same
KR102340078B1 (en) 2020-04-27 2021-12-16 한국조선해양 주식회사 Exhaust gas treatment apparatus for ship and ship having the same

Also Published As

Publication number Publication date
JP6079056B2 (en) 2017-02-15

Similar Documents

Publication Publication Date Title
JP6079056B2 (en) Denitration apparatus and denitration method
US7811527B2 (en) Exhaust purification with on-board ammonia production
JP2009517210A (en) Multi-stage system for selective catalytic reduction
JP2009276053A (en) Dry type three-way catalytic reduction method for gas turbine nox
KR20130018862A (en) Assembly and method for reducing nitrogen oxides, carbon monoxide and hydrocarbons in exhausts of internal combustion engines
JP2014098340A (en) Exhaust emission control system
JP7149852B2 (en) Selective catalytic reduction system and power unit provided with the same
JP2013007335A (en) Denitrification apparatus
KR20190116481A (en) Apparatus and Method for Desulfurization of Catalysts Used in a Lean Burn Methane Source Fuel Feed Mixed Combustion System
EP2264292A1 (en) Exhaust gas pyrification device
CN108533371B (en) Internal combustion engine with exhaust system
WO2015159698A1 (en) Exhaust gas purification system, catalyst and exhaust gas purification method
JP2015507127A (en) Exhaust gas system
JP6064498B2 (en) Denitration system
KR20210014509A (en) Catalyst for methane oxidation reaction at low temperature
KR101391334B1 (en) Device for purifying exhaust and vessel having the same
US20110120099A1 (en) SYSTEMS AND METHODS FOR REDUCING NOx BREAKTHROUGH
Fujita et al. Development of selective catalytic reduction for low-speed marine diesel engines
KR101251463B1 (en) Apparatus and method for purifying exhaust gas
KR20210014510A (en) Regeneration system for methane oxidation catalyst and methane oxidation reactor comprising the same
JP2020101175A (en) Exhaust gas post-treatment system
KR101571293B1 (en) Toxic Substance Reduction System Having UV Generating Part
WO1998029188A1 (en) Exhaust gas purification catalyst and waste gas purification method
JP2018013125A (en) Method for operating internal combustion engine and internal combustion engine
KR102388063B1 (en) Apparatus For Reducing Pollutants From Exhaust Gases OF Small Ships

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20150625

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20160309

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20160315

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20160513

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20161004

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20161124

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20161220

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20170102

R151 Written notification of patent or utility model registration

Ref document number: 6079056

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250