WO2014087910A1 - Catalyst for combustion exhaust gas purification and denitration purification method using this catalyst - Google Patents

Catalyst for combustion exhaust gas purification and denitration purification method using this catalyst Download PDF

Info

Publication number
WO2014087910A1
WO2014087910A1 PCT/JP2013/081991 JP2013081991W WO2014087910A1 WO 2014087910 A1 WO2014087910 A1 WO 2014087910A1 JP 2013081991 W JP2013081991 W JP 2013081991W WO 2014087910 A1 WO2014087910 A1 WO 2014087910A1
Authority
WO
WIPO (PCT)
Prior art keywords
catalyst
denitration
exhaust gas
combustion exhaust
performance
Prior art date
Application number
PCT/JP2013/081991
Other languages
French (fr)
Japanese (ja)
Inventor
恵美 庄野
日数谷　進
Original Assignee
日立造船株式会社
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 日立造船株式会社 filed Critical 日立造船株式会社
Publication of WO2014087910A1 publication Critical patent/WO2014087910A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/18—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the mordenite type
    • B01J29/20—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the mordenite type containing iron group metals, noble metals or copper
    • B01J29/24—Iron group metals or copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8628—Processes characterised by a specific catalyst
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
    • B01J29/42—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively containing iron group metals, noble metals or copper
    • B01J29/46—Iron group metals or copper
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/21—Organic compounds not provided for in groups B01D2251/206 or B01D2251/208
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20746—Cobalt
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/40—Nitrogen compounds
    • B01D2257/404—Nitrogen oxides other than dinitrogen oxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/12—After treatment, characterised by the effect to be obtained to alter the outside of the crystallites, e.g. selectivation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/12—After treatment, characterised by the effect to be obtained to alter the outside of the crystallites, e.g. selectivation
    • B01J2229/123—After treatment, characterised by the effect to be obtained to alter the outside of the crystallites, e.g. selectivation in order to deactivate outer surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/30—After treatment, characterised by the means used
    • B01J2229/32—Reaction with silicon compounds, e.g. TEOS, siliconfluoride
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
    • F01N2570/14—Nitrogen oxides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
    • F01N2590/02—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for marine vessels or naval applications
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/03—Adding substances to exhaust gases the substance being hydrocarbons, e.g. engine fuel

Definitions

  • the present invention relates to a combustion exhaust gas purification catalyst used for removing nitrogen oxides from combustion exhaust gas and the like, and a denitration purification method using this catalyst.
  • ammonia selective catalytic reduction When removing nitrogen oxides from combustion exhaust gas, ammonia selective catalytic reduction is the mainstream method.
  • This ammonia selective catalytic reduction method uses a denitration catalyst mainly composed of vanadium or titania as a catalyst, and uses ammonia as a reducing agent.
  • the ammonium sulfate precipitation temperature is about 280 ° C. in the case of combustion exhaust gas from marine engines.
  • the temperature of the combustion exhaust gas of the marine engine is about 250 ° C., which is lower than the ammonium sulfate precipitation temperature, ammonium sulfate is precipitated under normal marine engine operating conditions, and stable operation cannot be maintained. Therefore, the ammonia selective catalytic reduction method cannot be used in marine engines where the temperature of the combustion exhaust gas is low.
  • Denitration methods other than the ammonia selective catalytic reduction method include a direct decomposition method in which nitrogen oxide is decomposed into nitrogen and oxygen simply by contacting with a specific catalyst, and a reduction removal method using a reducing agent other than ammonia. is there.
  • the direct decomposition method can directly decompose nitrogen oxides by using a metal composite oxide having ionic conductivity, but the reaction temperature is 600 ° C. or higher. Therefore, it cannot be applied as it is to the denitration treatment of combustion exhaust gas from a marine engine whose combustion exhaust gas temperature is about 250 ° C.
  • Patent Document 8 describes a method using a catalyst in which ethanol and / or isopropyl alcohol is used as a reducing agent and a metal such as iron or cobalt is supported on ⁇ zeolite.
  • Patent Document 9 describes a method using a catalyst containing alcohol as a reducing agent and containing alumina, aluminum sulfate and silver as main components.
  • Japanese Patent Laid-Open No. 11-151440 Japanese Patent Laid-Open No. 11-342336 JP-A-11-342337 JP 2000-197822 A JP 2001-58130 A JP 2004-57947 A JP 2007-229558 A JP 2004-358454 A JP 2010-29783 A
  • the present invention has been made to solve the above problems, and an object of the present invention is to provide a denitration catalyst having long-term durability.
  • the catalyst of the present invention is a catalyst in which Co is supported on MFI zeolite for denitration purification of combustion exhaust gas at 300 ° C. or lower, and is subjected to silane treatment. .
  • the present invention also relates to a method for denitrating and purifying combustion exhaust gas at 300 ° C. or less, comprising the step of bringing the combustion exhaust gas into contact with a catalyst in the presence of alcohol as a reducing agent, the catalyst comprising Co as an MFI zeolite.
  • the present invention relates to a method which is a catalyst supported on a catalyst and is a catalyst which is subjected to silane treatment.
  • a wide variety of catalysts are known to be used for reducing nitrogen oxides present in combustion exhaust gas in the presence of reducing agents and decomposing them into those that are harmless to environmental health even if discharged outside.
  • a catalyst is generally used in a high temperature range exceeding 300 ° C.
  • the catalyst of the present invention is one in which Co is supported on MFI zeolite, which can function as a denitration catalyst in a temperature range of 300 ° C. or lower, and is particularly discharged from a marine engine. It has practical catalytic performance in the range of 180 to 300 ° C., more specifically in the temperature range of about 250 ° C.
  • alcohol is added as a reducing agent for reducing nitrogen oxides.
  • the alcohol is not particularly limited as long as it has a reducing power when added under conditions of 300 ° C. or lower, and examples thereof include methanol, ethanol, and isopropyl alcohol.
  • the main purpose of the present invention is to denitrate the combustion exhaust gas generated from the marine engine as described above.
  • the marine engine may go out to the open ocean for a long time, and the denitration catalyst is replaced on the open ocean. For this reason, it is a serious problem that the denitration performance of the denitration catalyst decreases with time.
  • the denitration catalyst of the present invention is a catalyst in which the above-mentioned Co is supported on MFI zeolite and is subjected to silane treatment, and the present inventors performed denitration treatment using this catalyst.
  • the catalyst performance it takes 120 to 140 hours or more for the catalyst performance to reach about 80% of the initial performance, and the denitration performance is improved for a sufficient period of time to denitrate the combustion exhaust gas from the marine engine. Found that can be maintained.
  • JP-A-8-71428 performs denitration using a hydrocarbon as a reducing agent.
  • the temperature range is 300 to 350 ° C.
  • silica vapor deposition suppresses combustion of hydrocarbons and studies have been made to improve catalyst selectivity, long-term durability has not been confirmed.
  • Japanese Patent Application Laid-Open No. 10-202109 has confirmed long-term durability by suppressing sintering of the supported metal.
  • CO is used as the reducing agent. Therefore, no catalyst has been reported that uses alcohol as a reducing agent and maintains long-term durability.
  • any method may be used as long as the catalyst surface can be covered with a sufficient amount of silica to suppress the precipitation of coke derived from the alcohol side reaction.
  • the silane agent include tetraethoxysilane, tetramethoxysilane, tetraisopropoxysilane, and the like.
  • the contact time with the silane agent is, for example, 0.5 to 12 hours, and the temperature at that time is, for example, 60 to 200 ° C.
  • Example 1 Preparation of silane-treated Co / MFI zeolite catalyst
  • 10 g of commercially available NH 4 -MFI type zeolite (SiO 2 / Al 2 O 3 molar ratio 28) was added to 200 ml of 0.1 M Co (NO 3 ) 2 aqueous solution, stirred at 80 ° C. overnight, filtered and washed And dried at 110 ° C. for 3 hours.
  • 3 g was filled in a test tube, baked at 400 ° C. for 1.5 hours under Air, and then cooled to 100 ° C. under N 2 .
  • Tetraethoxysilane was introduced into the gas phase by nitrogen bubbling over 1.5 hours. Thereafter, the temperature was raised to 400 ° C. under N 2 and Air calcination was performed for 1 hour to obtain a silane-treated Co / MFI zeolite catalyst.
  • Catalyst performance test A catalyst performance test was conducted on each catalyst obtained above. Each of the catalysts of Example 1 and Comparative Examples 1 to 4 was subjected to press molding, then pulverized, and sized to a mesh size of 28 to 14.
  • the obtained catalyst was packed into a stainless steel reaction tube having an inner diameter of 10.6 mm.
  • FIG. 1 shows a flow chart of a test apparatus used for a catalyst performance test.
  • the denitration test gas is introduced from the upper part of the reaction tube (1) filled with the catalyst through the line (2), and the gas that has been treated with the denitration catalyst from the lower part of the line (3) It is supposed to be discharged through.
  • the reaction tube (1) is provided with a thermocouple (4) so that the internal temperature can be grasped.
  • the test gas introduced into the reaction tube (1) through line (2) is prepared by mixing air from line (5) and NO / N 2 gas from line (6).
  • Each of the line (5) and the line (6) is provided with valves (7) and (8), and the flow rate of each gas is adjusted by adjusting the valves (7) and (8).
  • the mixing ratio is adjusted.
  • the mixed gas is introduced into the upper part of the evaporator (10) through the line (9), connected to the line (2) from the lower part, and supplied to the reaction tube (1). ing. Near the top of the evaporator (10), an aqueous ethanol solution used as a reducing agent is supplied through a line (11).
  • the aqueous ethanol solution introduced into the evaporator (10) is pumped up from the ethanol aqueous solution tank (12) by the metering pump (13) and then introduced into the evaporator (10) via the line (11). It has become.
  • the ethanol aqueous solution introduced by heating of a heater (not shown) is evaporated.
  • the treated gas discharged from the reactor (1) is discharged to the outside from the line (3) through the line (14), and a part thereof is subjected to gas analysis through the line (15).
  • test conditions are summarized in Table 1 below when the test is performed using the test apparatus shown in FIG.
  • “Balance” in Table 1 indicates that the gas composition is added so that the total gas composition becomes 100%, and the gas composition other than NO, ethanol, and water is occupied by air (indicated as Air in the table). It is shown that.
  • the NOx concentration at the outlet was measured using a NOx meter. From the measured value with a NOx meter, the NOx removal rate, which is the NOx removal performance of the catalyst, was calculated by the following mathematical formula.
  • FIG. 2 is a graph showing the change over time in the denitration rate calculated by the above test, and the denitration rates calculated in Tables 2 to 4 below are shown numerically.
  • the NOx removal performance drops to about 80% and about 50% of the initial NOx removal rate in about 30 hours, whereas the catalyst of Example 1 Then, it takes 120 to 140 hours for the catalyst performance to be about 80% of the initial value and about 50%, and the catalyst of Example 1 has a lower rate of denitration performance than the catalyst of Comparative Example 1. The result was slow.
  • the catalysts of Comparative Example 2 and Comparative Example 3 could not obtain high denitration performance from the initial stage. In other words, it was found that the useful life of the catalyst can be improved by about 4 times or more by subjecting the catalyst in which Co is supported on the MFI zeolite as in Example 1 to silane treatment.
  • the denitration performance decreases to about 50% in about 60 hours, whereas the metal
  • the catalyst of Example 1 prepared by silane treatment after loading requires 120 to 140 hours for the catalyst performance to reach about 50%.
  • the catalyst of Example 1 has a denitration performance higher than that of the catalyst of Comparative Example 4. As a result, the rate of decrease in the speed was reduced. That is, the result that the life of the catalyst was improved by about twice or more by applying the silane treatment after supporting the metal was obtained.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Toxicology (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The present invention provides a denitration catalyst which has long-term durability. The present invention is a catalyst for denitration purification of a combustion exhaust gas at 300°C or less, which is a catalyst obtained by having an MFI zeolite support Co and treated with silane. The present invention is a method for denitration purifying a combustion exhaust gas at 300°C or less, which comprises a step wherein a combustion exhaust gas is brought into contact with a catalyst in the presence of an alcohol that serves as a reducing agent, and wherein the catalyst is one obtained by having an MFI zeolite support Co and treated with silane.

Description

燃焼排ガス浄化用触媒およびこの触媒を用いる脱硝浄化方法Combustion exhaust gas purification catalyst and denitration purification method using this catalyst
　本発明は、燃焼排ガス等から窒素酸化物を除去するために用いられる燃焼排ガス浄化用触媒およびこの触媒を用いる脱硝浄化方法に関する。 The present invention relates to a combustion exhaust gas purification catalyst used for removing nitrogen oxides from combustion exhaust gas and the like, and a denitration purification method using this catalyst.
　燃焼排ガス中の窒素酸化物を除去する場合、その方法として、アンモニア選択触媒還元法が主流である。このアンモニア選択触媒還元法は、バナジウムやチタニアを主成分とする脱硝触媒を触媒として用い、アンモニアを還元剤として用いる方法である。 When removing nitrogen oxides from combustion exhaust gas, ammonia selective catalytic reduction is the mainstream method. This ammonia selective catalytic reduction method uses a denitration catalyst mainly composed of vanadium or titania as a catalyst, and uses ammonia as a reducing agent.
　アンモニア選択触媒還元法を用いて、重油等を燃焼させた後に生じた燃焼排ガスの脱硝を行う場合、重油等には硫黄が含有されているので、窒素酸化物と共に硫黄酸化物も燃焼排ガス中に生ずることになる。燃焼排ガス中においてこの硫黄酸化物と還元剤として添加されているアンモニアとが反応すると反応物として硫酸アンモニウム（硫安）となり、温度範囲によってはこれが燃焼排ガスを脱硝処理するための設備中に析出すると閉塞等の問題が生じる。このため、系内は硫安が析出しない温度域になるようにしなければならない。 When denitration of combustion exhaust gas generated after burning heavy oil or the like using the ammonia selective catalytic reduction method, sulfur is contained in the combustion exhaust gas together with nitrogen oxide because sulfur is contained in heavy oil or the like. Will occur. When this sulfur oxide reacts with ammonia added as a reducing agent in the combustion exhaust gas, it becomes ammonium sulfate (ammonium sulfate) as a reaction product. Depending on the temperature range, this deposits in the facility for denitration treatment of the combustion exhaust gas, etc. Problem arises. For this reason, the system must be in a temperature range in which ammonium sulfate does not precipitate.
　硫安析出温度は、舶用機関の燃焼排ガスの場合、約２８０℃である。しかしながら、舶用機関の燃焼排ガスの温度は約２５０℃であり、硫安析出温度より低いため、通常の舶用機関の運転条件では硫安が析出することとなり安定した操業を維持することができない。したがって、燃焼排ガスの温度が低い舶用機関ではアンモニア選択触媒還元法を使用することができない。 The ammonium sulfate precipitation temperature is about 280 ° C. in the case of combustion exhaust gas from marine engines. However, since the temperature of the combustion exhaust gas of the marine engine is about 250 ° C., which is lower than the ammonium sulfate precipitation temperature, ammonium sulfate is precipitated under normal marine engine operating conditions, and stable operation cannot be maintained. Therefore, the ammonia selective catalytic reduction method cannot be used in marine engines where the temperature of the combustion exhaust gas is low.
　アンモニア選択触媒還元法以外の脱硝方法としては、窒素酸化物を特定の触媒と接触させるだけで窒素と酸素に分解する直接分解法と、アンモニア以外の還元剤を使用して還元除去する方法とがある。 Denitration methods other than the ammonia selective catalytic reduction method include a direct decomposition method in which nitrogen oxide is decomposed into nitrogen and oxygen simply by contacting with a specific catalyst, and a reduction removal method using a reducing agent other than ammonia. is there.
　直接分解法は、特許文献１～７に示されているとおり、イオン導電性を有する金属複合酸化物を用いることで窒素酸化物の直接分解が可能であるが反応温度は６００℃以上となっており、上記のような燃焼排ガスの温度が約２５０℃である舶用機関からの燃焼排ガスの脱硝処理にはそのまま適用することはできない。 As shown in Patent Documents 1 to 7, the direct decomposition method can directly decompose nitrogen oxides by using a metal composite oxide having ionic conductivity, but the reaction temperature is 600 ° C. or higher. Therefore, it cannot be applied as it is to the denitration treatment of combustion exhaust gas from a marine engine whose combustion exhaust gas temperature is about 250 ° C.
　アンモニア以外の還元剤による還元除去法として特許文献８および９に記載された方法が知られている。特許文献８では、エタノールおよび／またはイソプロピルアルコールを還元剤とし、βゼオライトに鉄、コバルト等の金属を担持させた触媒を用いた方法が記載されている。特許文献９では、アルコールを還元剤とし、アルミナ、硫酸アルミニウムおよび銀を主成分として含有する触媒を用いた方法が記載されている。
特開平１１－１５１４４０号公報 特開平１１－３４２３３６号公報 特開平１１－３４２３３７号公報 特開２０００－１９７８２２号公報 特開２００１－５８１３０号公報 特開２００４－５７９４７号公報 特開２００７－２２９５５８号公報 特開２００４－３５８４５４号公報 特開２０１０－２９７８３号公報 As a reduction removal method using a reducing agent other than ammonia, methods described in Patent Documents 8 and 9 are known. Patent Document 8 describes a method using a catalyst in which ethanol and / or isopropyl alcohol is used as a reducing agent and a metal such as iron or cobalt is supported on β zeolite. Patent Document 9 describes a method using a catalyst containing alcohol as a reducing agent and containing alumina, aluminum sulfate and silver as main components.
Japanese Patent Laid-Open No. 11-151440 Japanese Patent Laid-Open No. 11-342336 JP-A-11-342337 JP 2000-197822 A JP 2001-58130 A JP 2004-57947 A JP 2007-229558 A JP 2004-358454 A JP 2010-29783 A
　ゼオライトに金属を担持させた触媒に、アルコールを接触させると、目的の脱硝反応以外にアルコールの脱水縮合反応等の副反応も起こる。このような副生成物によって触媒表面にコークが析出し経時的に脱硝性能が低下するという問題があった。 When the alcohol is brought into contact with a catalyst in which a metal is supported on zeolite, side reactions such as dehydration condensation reaction of alcohol occur in addition to the target denitration reaction. Such a by-product has a problem that coke is deposited on the catalyst surface and the denitration performance deteriorates with time.
　本発明は、上記問題を解決するためになされたものであり、長時間の耐久性を有する脱硝触媒を提供することを目的とする。 The present invention has been made to solve the above problems, and an object of the present invention is to provide a denitration catalyst having long-term durability.
　上記課題を解決するため、本発明の触媒は、３００℃以下で燃焼排ガスを脱硝浄化するための、ＣｏをＭＦＩゼオライトに担持させた触媒であって、シラン処理が施されてなる、ものである。 In order to solve the above problems, the catalyst of the present invention is a catalyst in which Co is supported on MFI zeolite for denitration purification of combustion exhaust gas at 300 ° C. or lower, and is subjected to silane treatment. .
　また、本発明は、３００℃以下で燃焼排ガスを脱硝浄化する方法であって、還元剤であるアルコールの存在下に該燃焼排ガスを触媒と接触させる工程を含み、該触媒は、ＣｏをＭＦＩゼオライトに担持させた触媒であって、シラン処理が施されてなる、触媒である、方法に関する。 The present invention also relates to a method for denitrating and purifying combustion exhaust gas at 300 ° C. or less, comprising the step of bringing the combustion exhaust gas into contact with a catalyst in the presence of alcohol as a reducing agent, the catalyst comprising Co as an MFI zeolite. The present invention relates to a method which is a catalyst supported on a catalyst and is a catalyst which is subjected to silane treatment.
　本発明では、３００℃以下で燃焼排ガスを脱硝浄化するための、ＣｏをＭＦＩゼオライトに担持させた触媒であって、シラン処理が施されてなる、ものであり、アルコールの副反応に由来する触媒表面上へのコーク析出による触媒性能の低下を抑制することができ、長時間にわたる耐久性を向上させることができる。 In the present invention, a catalyst in which Co is supported on MFI zeolite for denitration purification of combustion exhaust gas at 300 ° C. or lower, which is subjected to silane treatment, and is derived from a side reaction of alcohol A decrease in catalyst performance due to coke deposition on the surface can be suppressed, and durability over a long period of time can be improved.
触媒性能試験に用いられる試験装置のフロー図である。It is a flowchart of the test apparatus used for a catalyst performance test. 実施例１および比較例２～４の触媒の性能試験により算出された脱硝率の経時変化を示すグラフである。6 is a graph showing the change over time in the denitration rate calculated by the performance test of the catalyst of Example 1 and Comparative Examples 2 to 4.
　以下、本発明の触媒および燃焼排ガスを脱硝浄化する方法について詳細に説明する。 Hereinafter, the method of denitrating and purifying the catalyst and combustion exhaust gas of the present invention will be described in detail.
　還元剤の存在下に燃焼排ガス中に存在する窒素酸化物を還元して、外部に排出しても環境衛生上無害であるものに分解するために用いられる触媒として多種多様のものが知られているが、こうした触媒は一般に３００℃超の高温域で使用されている。 A wide variety of catalysts are known to be used for reducing nitrogen oxides present in combustion exhaust gas in the presence of reducing agents and decomposing them into those that are harmless to environmental health even if discharged outside. However, such a catalyst is generally used in a high temperature range exceeding 300 ° C.
　これに対して本発明の触媒は、ＣｏをＭＦＩゼオライトに担持させたものであり、このものは、３００℃以下の温度域で脱硝触媒として機能することができ、特に、舶用機関から排出される１８０～３００℃の範囲、より具体的には２５０℃程度の温度範囲で実用的な触媒性能を有する。 On the other hand, the catalyst of the present invention is one in which Co is supported on MFI zeolite, which can function as a denitration catalyst in a temperature range of 300 ° C. or lower, and is particularly discharged from a marine engine. It has practical catalytic performance in the range of 180 to 300 ° C., more specifically in the temperature range of about 250 ° C.
　本発明による触媒を用いて３００℃以下で燃焼排ガスを脱硝浄化するに際して、窒素酸化物を還元させる還元剤としてアルコールが添加される。アルコールとしては、３００℃以下の条件で添加された場合に還元力を有するものであれば特に限定されるものではないが、例えば、メタノール、エタノール、イソプロピルアルコールが挙げられる。 When denitrating and purifying combustion exhaust gas at 300 ° C. or lower using the catalyst according to the present invention, alcohol is added as a reducing agent for reducing nitrogen oxides. The alcohol is not particularly limited as long as it has a reducing power when added under conditions of 300 ° C. or lower, and examples thereof include methanol, ethanol, and isopropyl alcohol.
　上記のようなＣｏをＭＦＩゼオライトに担持させた触媒に、アルコールを接触させると脱硝反応以外にアルコールの脱水縮合反応等の副反応が生じることが分かっている。このような副反応が生じると、触媒表面上にコークが析出することとなり、経時的に脱硝触媒の脱硝性能が低下する結果となる。 It has been found that when a catalyst in which Co is supported on MFI zeolite as described above is brought into contact with alcohol, side reactions such as a dehydration condensation reaction of alcohol occur in addition to the denitration reaction. When such a side reaction occurs, coke is deposited on the catalyst surface, resulting in a decrease in the denitration performance of the denitration catalyst over time.
　本発明は、上記のように舶用機関から生じる燃焼排ガスを脱硝処理することを主目的としているが、舶用機関は、長期間にわたって外洋に出ることもあり、外洋上では脱硝触媒の交換作業を行うことが困難である都合上、経時的に脱硝触媒の脱硝性能が低下することは重大な問題となる。 The main purpose of the present invention is to denitrate the combustion exhaust gas generated from the marine engine as described above. However, the marine engine may go out to the open ocean for a long time, and the denitration catalyst is replaced on the open ocean. For this reason, it is a serious problem that the denitration performance of the denitration catalyst decreases with time.
　本発明者らが、ＣｏをＭＦＩゼオライトに担持させた触媒を用いて脱硝処理を行ったところ、３０時間程度で初期性能の約８割程度の性能になることが分かった。このように早期に性能が低下する触媒は舶用機関からの燃焼排ガス処理のためには不適である。 When the present inventors performed a denitration treatment using a catalyst in which Co is supported on MFI zeolite, it was found that the performance is about 80% of the initial performance in about 30 hours. Thus, a catalyst whose performance deteriorates at an early stage is not suitable for the treatment of combustion exhaust gas from marine engines.
　これに対して、本発明の脱硝触媒は、上記のＣｏをＭＦＩゼオライトに担持させた触媒に対してシラン処理を施したものであり、本発明者らがこのものを用いて脱硝処理を行ったところ、触媒性能が初期性能の８割程度になるのに１２０～１４０時間か若しくはそれ以上の時間を要することが分かり、舶用機関からの燃焼排ガスを脱硝処理するために十分な期間にわたって脱硝性能を維持することができることを見出した。 On the other hand, the denitration catalyst of the present invention is a catalyst in which the above-mentioned Co is supported on MFI zeolite and is subjected to silane treatment, and the present inventors performed denitration treatment using this catalyst. However, it can be seen that it takes 120 to 140 hours or more for the catalyst performance to reach about 80% of the initial performance, and the denitration performance is improved for a sufficient period of time to denitrate the combustion exhaust gas from the marine engine. Found that can be maintained.
　ここで、金属担持ゼオライト（ＺＳＭ－５）にシリカ蒸着を施した触媒を用いた技術として、特開平８－７１４２８号公報では、炭化水素を還元剤に用いて脱硝を行っている。しかしながら、温度領域は３００～３５０℃であり、シリカ蒸着を行うことで炭化水素の燃焼を抑制し触媒の選択性向上の検討を行っているが長時間の耐久性は未確認である。同様に金属担持ゼオライト（モルデナイト）にシリカ蒸着を行った技術として、特開平１０－２０２１０９号公報では、担持金属のシンタリングを抑制し長時間の耐久性を確認している。しかしながら、還元剤にはＣＯを用いている。よって、還元剤にアルコールを用いて長時間の耐久性を保持した触媒は報告されていない。 Here, as a technique using a catalyst obtained by subjecting a metal-supported zeolite (ZSM-5) to silica deposition, JP-A-8-71428 performs denitration using a hydrocarbon as a reducing agent. However, the temperature range is 300 to 350 ° C., and while silica vapor deposition suppresses combustion of hydrocarbons and studies have been made to improve catalyst selectivity, long-term durability has not been confirmed. Similarly, as a technique for performing silica vapor deposition on a metal-supported zeolite (mordenite), Japanese Patent Application Laid-Open No. 10-202109 has confirmed long-term durability by suppressing sintering of the supported metal. However, CO is used as the reducing agent. Therefore, no catalyst has been reported that uses alcohol as a reducing agent and maintains long-term durability.
　本発明における触媒に対するシラン処理は、触媒表面をアルコールの副反応に由来するコークの析出を抑制するのに十分な量のシリカで覆うことができれば如何なる方法を用いてもよいが、例えば、シラン剤を気相にて触媒と接触させることにより行われる。シラン剤としては、例えば、テトラエトキシシラン、テトラメトキシシラン、テトライソプロポキシシラン等が挙げられ、シラン剤との接触時間は、例えば、０．５～１２時間であり、その際の温度は、例えば、６０～２００℃である。 For the silane treatment of the catalyst in the present invention, any method may be used as long as the catalyst surface can be covered with a sufficient amount of silica to suppress the precipitation of coke derived from the alcohol side reaction. By contacting with a catalyst in the gas phase. Examples of the silane agent include tetraethoxysilane, tetramethoxysilane, tetraisopropoxysilane, and the like. The contact time with the silane agent is, for example, 0.5 to 12 hours, and the temperature at that time is, for example, 60 to 200 ° C.
　（実施例）
　次に、本発明に沿った実施例、およびこれとの比較を示すための比較例を実際に行ったので以下に説明する。 (Example)
Next, an example according to the present invention and a comparative example for showing a comparison with this example were actually performed and will be described below.
　（実施例１：シラン処理Ｃｏ／ＭＦＩゼオライト触媒の調製）
　市販のＮＨ４－ＭＦＩ型ゼオライト（ＳｉＯ２／Ａｌ２Ｏ３モル比　２８）１０ｇを０．１ＭのＣｏ（ＮＯ３）２水溶液２００ｍｌに添加し、８０℃で一晩攪拌した後、ろ過、洗浄し、１１０℃で３時間乾燥させた。その内、３ｇを試験管に充填し、Ａｉｒ下に４００℃にて１．５時間焼成した後、Ｎ２下に１００℃に降温させた。そこへ窒素バブリングにてテトラエトキシシランを１．５時間にわたって気相導入した。その後Ｎ２下にて４００℃まで昇温させ、Ａｉｒ焼成を１時間にわたって行い、シラン処理Ｃｏ／ＭＦＩゼオライト触媒を得た。 (Example 1: Preparation of silane-treated Co / MFI zeolite catalyst)
10 g of commercially available NH 4 -MFI type zeolite (SiO 2 / Al 2 O 3 molar ratio 28) was added to 200 ml of 0.1 M Co (NO 3 ) 2 aqueous solution, stirred at 80 ° C. overnight, filtered and washed And dried at 110 ° C. for 3 hours. Among them, 3 g was filled in a test tube, baked at 400 ° C. for 1.5 hours under Air, and then cooled to 100 ° C. under N 2 . Tetraethoxysilane was introduced into the gas phase by nitrogen bubbling over 1.5 hours. Thereafter, the temperature was raised to 400 ° C. under N 2 and Air calcination was performed for 1 hour to obtain a silane-treated Co / MFI zeolite catalyst.
　（比較例１：Ｃｏ／ＭＦＩゼオライト触媒の調製）
　市販のＮＨ４－ＭＦＩ型ゼオライト（ＳｉＯ２／Ａｌ２Ｏ３モル比　２８）１０ｇを０．１ＭのＣｏ（ＮＯ３）２水溶液２００ｍｌに添加し、８０℃で一晩攪拌した後、ろ過、洗浄し、１１０℃で３時間乾燥させ、Ｃｏ／ＭＦＩゼオライト触媒を得た。 (Comparative Example 1: Preparation of Co / MFI zeolite catalyst)
10 g of commercially available NH 4 -MFI type zeolite (SiO 2 / Al 2 O 3 molar ratio 28) was added to 200 ml of 0.1 M Co (NO 3 ) 2 aqueous solution, stirred at 80 ° C. overnight, filtered and washed And dried at 110 ° C. for 3 hours to obtain a Co / MFI zeolite catalyst.
　（比較例２：シラン処理Ｃｏ／ＭＯＲゼオライト触媒の調製）
　市販のＮＨ４－ＭＯＲ型ゼオライト（ＳｉＯ２／Ａｌ２Ｏ３モル比　１４）１０ｇを０．２ＭのＣｏ（ＮＯ３）２水溶液２００ｍｌに添加し、８０℃で一晩攪拌した後、ろ過、洗浄し、１１０℃で３時間乾燥させた。その内、３ｇを試験管に充填し、Ａｉｒ下４００℃にて１．５時間焼成した後、Ｎ２下１００℃に降温させた。そこへ窒素バブリングにてテトラエトキシシランを３時間にわたって気相導入した。その後Ｎ２下にて４００℃まで昇温させ、Ａｉｒ焼成を１時間にわたって行い、シラン処理Ｃｏ／ＭＯＲゼオライト触媒を得た。 (Comparative Example 2: Preparation of silane-treated Co / MOR zeolite catalyst)
10 g of commercially available NH 4 -MOR type zeolite (SiO 2 / Al 2 O 3 molar ratio 14) was added to 200 ml of 0.2 M Co (NO 3 ) 2 aqueous solution, stirred at 80 ° C. overnight, filtered, washed And dried at 110 ° C. for 3 hours. Among them, 3 g was filled in a test tube, fired at 400 ° C. under Air for 1.5 hours, and then cooled to 100 ° C. under N 2 . Tetraethoxysilane was introduced into the vapor phase by nitrogen bubbling over 3 hours. Thereafter, the temperature was raised to 400 ° C. under N 2 and Air calcination was performed for 1 hour to obtain a silane-treated Co / MOR zeolite catalyst.
　（比較例３：Ｃｏ／ＭＯＲゼオライト触媒の調製）
　市販のＨ－ＭＯＲ型ゼオライト（ＳｉＯ２／Ａｌ２Ｏ３モル比　１４）１０ｇを０．２ＭのＣｏ（ＮＯ３）２水溶液２００ｍｌに添加し、８０℃で一晩攪拌した後、ろ過、洗浄し、１１０℃で３時間乾燥し、Ｃｏ／ＭＯＲゼオライト触媒を得た。 (Comparative Example 3: Preparation of Co / MOR zeolite catalyst)
10 g of commercially available H-MOR type zeolite (SiO 2 / Al 2 O 3 molar ratio 14) was added to 200 ml of 0.2 M Co (NO 3 ) 2 aqueous solution, stirred at 80 ° C. overnight, filtered and washed. And dried at 110 ° C. for 3 hours to obtain a Co / MOR zeolite catalyst.
　（比較例４：Ｃｏ／シラン処理ＭＦＩゼオライト触媒の調製）
　市販のＮＨ４－ＭＦＩ型ゼオライト（ＳｉＯ２／Ａｌ２Ｏ３モル比　２８）３ｇを試験管に充填し、Ａｉｒ下に４００℃にて１．５時間焼成した後、Ｎ２下に１００℃に降温させた。そこへ窒素バブリングにてテトラエトキシシランを１．５時間にわたって気相導入した。その後Ｎ２下にて４００℃まで昇温させ、Ａｉｒ焼成を１時間にわたって行った。得られた粉末を０．１ＭのＣｏ（ＮＯ３）２水溶液２００ｍｌに添加し、８０℃で一晩攪拌した後、ろ過、洗浄し、１１０℃で３時間乾燥させ、Ｃｏ／シラン処理ＭＦＩゼオライト触媒を得た。 (Comparative Example 4: Preparation of Co / silane-treated MFI zeolite catalyst)
A test tube was filled with 3 g of commercially available NH 4 -MFI type zeolite (SiO 2 / Al 2 O 3 molar ratio 28), calcined at 400 ° C. for 1.5 hours under Air, and then at 100 ° C. under N 2. The temperature was lowered. Tetraethoxysilane was introduced into the gas phase by nitrogen bubbling over 1.5 hours. Thereafter, the temperature was raised to 400 ° C. under N 2 , and Air firing was performed for 1 hour. The obtained powder was added to 200 ml of 0.1M Co (NO 3 ) 2 aqueous solution, stirred at 80 ° C. overnight, filtered, washed, dried at 110 ° C. for 3 hours, and Co / silane treated MFI zeolite catalyst. Got.
　（触媒性能試験）
　上記で得られた各触媒について触媒性能試験を行った。上記の実施例１および比較例１～４の触媒のそれぞれについて、プレス成形を行い、その後に粉砕し、メッシュサイズ２８から１４に整粒した。 (Catalyst performance test)
A catalyst performance test was conducted on each catalyst obtained above. Each of the catalysts of Example 1 and Comparative Examples 1 to 4 was subjected to press molding, then pulverized, and sized to a mesh size of 28 to 14.
　得られた触媒を、内径１０．６ｍｍのステンレス製反応管に充填した。 The obtained catalyst was packed into a stainless steel reaction tube having an inner diameter of 10.6 mm.
　図１は、触媒性能試験に用いられる試験装置のフロー図を示している。 FIG. 1 shows a flow chart of a test apparatus used for a catalyst performance test.
　上記の触媒が充填された反応管（１）の上部からライン（２）を通じて脱硝試験用のガスが導入されるようになっており、下部から脱硝触媒により処理を終えたガスがライン（３）を通じて排出されるようになっている。また、この反応管（１）には、内部の温度を把握することができるように熱電対（４）が設置されている。 The denitration test gas is introduced from the upper part of the reaction tube (1) filled with the catalyst through the line (2), and the gas that has been treated with the denitration catalyst from the lower part of the line (3) It is supposed to be discharged through. The reaction tube (1) is provided with a thermocouple (4) so that the internal temperature can be grasped.
　ライン（２）を通じて反応管（１）に導入される試験用のガスは、ライン（５）からの空気およびライン（６）からのＮＯ／Ｎ２ガスを混合することにより調製される。ライン（５）およびライン（６）のそれぞれにはバルブ（７）および（８）が設けられており、バルブ（７）および（８）を調整することにより各ガスの流量を調整し、ガス流量および混合比が調整されるようになっている。 The test gas introduced into the reaction tube (1) through line (2) is prepared by mixing air from line (5) and NO / N 2 gas from line (6). Each of the line (5) and the line (6) is provided with valves (7) and (8), and the flow rate of each gas is adjusted by adjusting the valves (7) and (8). The mixing ratio is adjusted.
　混合後のガスは、ライン（９）を通じて蒸発器（１０）の上部に導入されるようになっており、下部からライン（２）に接続され、反応管（１）に供給されるようになっている。この蒸発器（１０）の上部寄りには、還元剤として利用されるエタノール水溶液がライン（１１）を通じて供給されるようになっている。 The mixed gas is introduced into the upper part of the evaporator (10) through the line (9), connected to the line (2) from the lower part, and supplied to the reaction tube (1). ing. Near the top of the evaporator (10), an aqueous ethanol solution used as a reducing agent is supplied through a line (11).
　蒸発器（１０）に導入されるエタノール水溶液は、エタノール水溶液槽（１２）から定量送液ポンプ（１３）で汲み上げられた後、ライン（１１）を経て蒸発器（１０）に導入されるようになっている。蒸発器（１０）では、図示しないヒータの加熱により導入されたエタノール水溶液を蒸発させる。 The aqueous ethanol solution introduced into the evaporator (10) is pumped up from the ethanol aqueous solution tank (12) by the metering pump (13) and then introduced into the evaporator (10) via the line (11). It has become. In the evaporator (10), the ethanol aqueous solution introduced by heating of a heater (not shown) is evaporated.
　反応器（１）から排出された処理済みのガスは、ライン（３）からライン（１４）を経て外部に排出されると共に、一部についてライン（１５）を経てガス分析に供される。 The treated gas discharged from the reactor (1) is discharged to the outside from the line (3) through the line (14), and a part thereof is subjected to gas analysis through the line (15).
　図１に示す試験装置を用いて試験を行うに際して、その試験条件を下記表１にまとめる。 The test conditions are summarized in Table 1 below when the test is performed using the test apparatus shown in FIG.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１における「Ｂａｌａｎｃｅ」は、ガス組成がトータルで１００％になるように添加されるものを表し、ＮＯ、エタノール、水以外のガス組成が空気（表中ではＡｉｒと表示）によって占められていることを示している。 “Balance” in Table 1 indicates that the gas composition is added so that the total gas composition becomes 100%, and the gas composition other than NO, ethanol, and water is occupied by air (indicated as Air in the table). It is shown that.
　ガス分析は、ＮＯｘ計を用いて出口ＮＯｘ濃度を測定した。ＮＯｘ計での測定値から、下記の数式によって触媒のＮＯｘ除去性能である脱硝率を算出した。 For gas analysis, the NOx concentration at the outlet was measured using a NOx meter. From the measured value with a NOx meter, the NOx removal rate, which is the NOx removal performance of the catalyst, was calculated by the following mathematical formula.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　図２に、上記試験により算出された脱硝率の経時変化をグラフで示し、下記表２～４に算出された脱硝率を数値にて示す。 FIG. 2 is a graph showing the change over time in the denitration rate calculated by the above test, and the denitration rates calculated in Tables 2 to 4 below are shown numerically.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　図２および表２に示されるように、比較例１の触媒では３０時間程度で初期の脱硝率の約８割程度、約５０％に脱硝性能が低下するのに対して、実施例１の触媒では、触媒性能が初期の約８割程度、約５０％になるのに１２０～１４０時間の時間を要し、実施例１の触媒では、比較例１の触媒よりも脱硝性能の低下の速度が遅くなるという結果が得られた。 As shown in FIG. 2 and Table 2, in the catalyst of Comparative Example 1, the NOx removal performance drops to about 80% and about 50% of the initial NOx removal rate in about 30 hours, whereas the catalyst of Example 1 Then, it takes 120 to 140 hours for the catalyst performance to be about 80% of the initial value and about 50%, and the catalyst of Example 1 has a lower rate of denitration performance than the catalyst of Comparative Example 1. The result was slow.
　また、図２および表３に示されるように、比較例２および比較例３の触媒では初期段階から高い脱硝性能を得ることができなかった。つまり、実施例１のようにＣｏをＭＦＩゼオライトに担持させた触媒に対してシラン処理を施すことにより、触媒の耐用期間を約４倍以上に向上させることができることが分かった。 Further, as shown in FIG. 2 and Table 3, the catalysts of Comparative Example 2 and Comparative Example 3 could not obtain high denitration performance from the initial stage. In other words, it was found that the useful life of the catalyst can be improved by about 4 times or more by subjecting the catalyst in which Co is supported on the MFI zeolite as in Example 1 to silane treatment.
　さらに、図２および表４に示されるように、シラン処理後に金属を担持させることにより調製した比較例４の触媒では、６０時間程度で約５０％に脱硝性能が低下するのに対して、金属担持後にシラン処理することにより調製した実施例１の触媒では、触媒性能が約５０％になるのに１２０～１４０時間を要し、実施例１の触媒では、比較例４の触媒よりも脱硝性能の低下の速度が遅くなるという結果が得られた。つまり、金属担持後にシラン処理を施すことにより触媒の寿命が約２倍以上に向上する結果を得た。 Further, as shown in FIG. 2 and Table 4, in the catalyst of Comparative Example 4 prepared by supporting the metal after the silane treatment, the denitration performance decreases to about 50% in about 60 hours, whereas the metal The catalyst of Example 1 prepared by silane treatment after loading requires 120 to 140 hours for the catalyst performance to reach about 50%. The catalyst of Example 1 has a denitration performance higher than that of the catalyst of Comparative Example 4. As a result, the rate of decrease in the speed was reduced. That is, the result that the life of the catalyst was improved by about twice or more by applying the silane treatment after supporting the metal was obtained.
１　反応管
４　熱電対
７、８　バルブ
１０　蒸発器
１２　エタノール水溶液槽
１３　定量送液ポンプ
２、３、５、６、９、１１、１４、１５　ライン 1 Reaction tube 4 Thermocouple 7, 8 Valve 10 Evaporator 12 Ethanol aqueous solution tank 13 Liquid feed pump 2, 3, 5, 6, 9, 11, 14, 15 lines

Claims (2)

  1. 　３００℃以下で燃焼排ガスを脱硝浄化するための、ＣｏをＭＦＩゼオライトに担持させた触媒であって、シラン処理が施されてなる、触媒。 A catalyst in which Co is supported on MFI zeolite for denitration purification of combustion exhaust gas at 300 ° C. or lower, and is subjected to silane treatment.
  2. 　３００℃以下で燃焼排ガスを脱硝浄化する方法であって、還元剤であるアルコールの存在下で該燃焼排ガスを触媒と接触させる工程を含み、該触媒は、ＣｏをＭＦＩゼオライトに担持させた触媒であって、シラン処理が施されてなる、触媒である、方法。 A method for denitrating and purifying combustion exhaust gas at 300 ° C. or lower, comprising a step of contacting the combustion exhaust gas with a catalyst in the presence of alcohol as a reducing agent, the catalyst being a catalyst in which Co is supported on MFI zeolite. A method, wherein the catalyst is a silane treatment.
PCT/JP2013/081991 2012-12-03 2013-11-28 Catalyst for combustion exhaust gas purification and denitration purification method using this catalyst WO2014087910A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012264076A JP2016027935A (en) 2012-12-03 2012-12-03 Catalyst for purifying flue gas, and denitration purification method using catalyst
JP2012-264076 2012-12-03

Publications (1)

Publication Number Publication Date
WO2014087910A1 true WO2014087910A1 (en) 2014-06-12

Family

ID=50883329

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/081991 WO2014087910A1 (en) 2012-12-03 2013-11-28 Catalyst for combustion exhaust gas purification and denitration purification method using this catalyst

Country Status (2)

Country Link
JP (1) JP2016027935A (en)
WO (1) WO2014087910A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3437736A4 (en) * 2016-03-31 2019-11-20 Hitachi Zosen Corporation Exhaust gas cleaning catalyst

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06170168A (en) * 1992-12-03 1994-06-21 Tosoh Corp Removal of nitrogen oxide
JPH0871428A (en) * 1994-09-09 1996-03-19 Ishikawajima Harima Heavy Ind Co Ltd Denitration catalyst for exhaust gas from dieselengine
JPH08150324A (en) * 1991-02-14 1996-06-11 Sekiyu Sangyo Kasseika Center Method for catalytically reducing nitrogen oxide
JPH10202109A (en) * 1997-01-17 1998-08-04 Tokyo Gas Co Ltd Catalyst for purification of nox-containing exhaust gas and production thereof and purification thereof
JP2010029783A (en) * 2008-07-29 2010-02-12 Babcock Hitachi Kk Catalyst for removal of nitrogen oxide

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08150324A (en) * 1991-02-14 1996-06-11 Sekiyu Sangyo Kasseika Center Method for catalytically reducing nitrogen oxide
JPH06170168A (en) * 1992-12-03 1994-06-21 Tosoh Corp Removal of nitrogen oxide
JPH0871428A (en) * 1994-09-09 1996-03-19 Ishikawajima Harima Heavy Ind Co Ltd Denitration catalyst for exhaust gas from dieselengine
JPH10202109A (en) * 1997-01-17 1998-08-04 Tokyo Gas Co Ltd Catalyst for purification of nox-containing exhaust gas and production thereof and purification thereof
JP2010029783A (en) * 2008-07-29 2010-02-12 Babcock Hitachi Kk Catalyst for removal of nitrogen oxide

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
M. SEITZ ET AL.: "Silanation as a means to reduce deactivation", CATALYST DEACTIVATION, vol. 126, 1999, pages 221 - 228 *
XIAOLONG HAN ET AL.: "Tuning the hydrophobicity of ZSM-5 zeolites by surface silanization using alkyltrichlorosilane", APPLIED SURFACE SCIENCE, vol. 257, pages 9525 - 9531 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3437736A4 (en) * 2016-03-31 2019-11-20 Hitachi Zosen Corporation Exhaust gas cleaning catalyst

Also Published As

Publication number Publication date
JP2016027935A (en) 2016-02-25

Similar Documents

Publication Publication Date Title
JP5094717B2 (en) Method and apparatus for combining catalysts for reducing NOx in combustion products
CN109268109B (en) Method and system for purifying exhaust gases from an internal combustion engine
KR20090114480A (en) Bifunctional catalysts for selective ammonia oxidation
Yi et al. Combination of Pt@ CeO2/MCM-56 and CeO2-CuO/MCM-56 to purify the exhaust emissions from diesel vehicles
JP5164821B2 (en) Nitrogen oxide selective catalytic reduction catalyst
KR101208888B1 (en) Composition based on zirconium oxide, yttrium oxide and tungsten oxide, method of preparation and use as catalyst or catalyst support
JP2008296224A (en) Nitrogen oxide removing catalyst, nitrogen oxide removing method using it, and nitrogen oxide removing device
WO2014087910A1 (en) Catalyst for combustion exhaust gas purification and denitration purification method using this catalyst
Zhao et al. Insights into the superior resistance of In-Co3O4-Ga2O3/H-Beta to SO2 and H2O in the selective catalytic reduction of NOx by CH4
JP2007038155A (en) Catalyst for selective reduction nitrogen oxide by carbon monoxide and its preparing method
JP6126858B2 (en) Exhaust gas purification device for internal combustion engine
JP5285459B2 (en) Exhaust gas purification catalyst and exhaust gas purification method
WO2015146913A1 (en) Combustion exhaust gas purifying catalyst and method for purifying combustion exhaust gas
JP5004084B2 (en) Method for catalytic reduction and removal of nitrogen oxides in exhaust gas
WO2013069713A1 (en) Catalyst for removing nitrogen oxide contained in combustion exhaust gas, and method for removing nitrogen oxide using said catalyst
JP2014144424A (en) Catalyst for decomposing ammonia
WO2014142046A1 (en) Method for reducing and removing nitrogen oxides in exhaust gas
JP3087321B2 (en) Exhaust gas purification catalyst and exhaust gas purification method
Wang et al. Influence of Calcination Temperature over Vanadium–Molybdenum Catalysts for the Selective Catalytic Reduction of NO x with NH3
Xu et al. Exploring the Impact of Palladium Species’ State on Catalytic Ammonia Elimination over Palladium Catalysts
JP6232223B2 (en) Exhaust gas purification method
JP2009056459A (en) Catalyst and method for cleaning exhaust gas
JP2018015708A (en) Exhaust gas purification catalyst and exhaust gas purification apparatus using the same
JPH0889813A (en) Catalyst for denitrification and method for denitrification using it
JPH08318163A (en) Catalyst for removal of nox in exhaust gas

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13859761

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13859761

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP