• Title/Summary/Keyword: catalytic reduction

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A Theoretical Study on Exhaust Gas Reduction by Oxidation Catalyst in Diesel Engine (디젤기관에서 산화촉매장치에 의한 배기가스 저감에 관한 이론적 연구)

  • 한영출;김종춘;김태섭
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.4
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    • pp.179-189
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    • 1997
  • Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now studied actively. In this study, a transient one-dimensional model developed to simulate the thermal and conversion characteristics of adiabatic monolithic converters operating under warm up conditions is presented. This model takes into account the gas solid heat and mass transfer, axial heat conduction, chemical reactions and the related heat release. The model has been used to analyze the transient response of an axisymmetric catalytic converter during a warm-up as a function of catalyst design parameters and operation conditions in order to observe their effects on the lightoff behaviour. The experimental test was carried out 2400 cc light diesel engine with DOC.

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Air Pollution by Automobiles and Ways of Reduction (자동차가 대기오염에 미치는 영향과 저감방안)

  • 김대식
    • Journal of the Korean Professional Engineers Association
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    • v.34 no.4
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    • pp.69-73
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    • 2001
  • Due to the rapid increase of automobiles and daily driving distances, air pollution by automobiles is still dominant problem of large city in spite of strict emission refutation and development of reduction technologies. Among the air pollution resources of automobile , industry. electricity generation and heating. automobile keeps 51% of total nationwide air pollution in 1998 and this proportion Is increasing in large cities from 65% to 85%. To reduce these air pollution. catalytic converter and electronic engine control, exhaust gas re-circulation and evaporative emission control system have continuously developed and applied to automobiles since 1987. Also strong emission standards and emission durability warranty have enforced and monitored annually by sampling several vehicle models. But technologies and regulations are incomplete, driver should participate in reducing air pollution for himself by planning driving, avoiding unnecessary idle and air conditioning, keeping periodic maintenance and using mass transportation.

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Study of Additive Effects on Nitrogen Oxides Reduction for Combustion Emission Gas (소각시설에서 질소산화물 환원처리를 위한 반응제의 영향 연구)

  • 동종인;박정희;장주호;강경희;이종길
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.145-146
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    • 2003
  • 질소산화물은 천연가스, 석유, 석탄과 같은 화석연료 연소 시에 배출되는 대표적 오염물질로 산성비를 유발시키며, 오존, PAN, aldehyde와 같은 광화학 산화물을 형성하여 광화학 스모그를 유발한다. 따라서 NOx 제어의 필요성은 더욱 강조되고 있다. NOx 처리 공정 중 대표적인 SNCR(Selective Non-Catalytic Reduction)공정은 N-계열 시약(환원제)을 노내의 온도가 90$0^{\circ}C$에서 110$0^{\circ}C$인 구역으로 주입하여 NOx가 복잡한 단위반응들을 거쳐서 N2와 $H_2O$로 분해되는 저감기술의 하나로서 초기 설치비가 저렴하고 단기간에 쉽게 설치 가능한 기술이지만, 대부분 외국기술의 도입에 의존하고 있는 실정이므로 국내개발을 필요로 한다. (중략)

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Reduction of Aromatic Nitro Group by Activated Cu-Zn-$NH_2NH_2{\cdot}H_2O$ in Ethanol (활성화시킨 Cu-Zn 과 히드라진을 이용한 방향족 니트로 화합물의 환원반응)

  • Byung Hee Han;Dae Hyun Shin;Hyun Ro Lee
    • Journal of the Korean Chemical Society
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    • v.33 no.6
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    • pp.577-581
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    • 1989
  • Activated Cu-Zn by the reaction of aqueous cupric sulfate and excess Zn showed the exceptional catalytic activity for the reduction of aromatic nitro compounds to the corresponding amino compounds in the presence of hydrazine monohydrate in ethanol. But, aliphatic nitro compounds were not reduced to the amino compounds.

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Emission characteristics of Natural Gas Fueled Vehicl and its Purification Technologies (천연가스 자동차의 Emission 배출특성 및 저감법)

  • 최병철;이지연;손건석;이귀영
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.127-135
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    • 1997
  • Experiments have been conducted to investigate emission characteristics of compressed natural gas fueled vehicle(CNGV) by the FTP 75 mode test. Its purification technologies were also investigated. It was found that CNGV was operated on the rich A/F condition by comparison with gasoline vehicle. The Pd catalyst was higher in methane purification performance than Pt and Pd/Pt/Rh catalysts. Up to 60% portion of the accumulative HC emissions(that contains above 80% methane) form CNGV occurs during the first phase of the FTP 75 mode. CO that is exhausted at rich conditions of the air-fuel ratio more than lean conditions should be used for the catalytic reduction of NOX, because the methane is not the effective reduction for NOX in the CNGV with 3-way catalyst system.

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Fast Light-Off of Catalyst using Cranking Exhaust Gas Ignition (시동 배기가스 점화기술을 이용한 촉매의 예열시간 단축)

  • 조용석;엄인용;이윤석;김득상;김충식;천준영;최진욱
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.2
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    • pp.43-49
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    • 2001
  • In order to satisfy the ULEV emissions regulation, fast light-off of a catalyst is essential for reduction of HC and CO emissions during the cold start. Cranking Exhaust Gas Ignition(CEGI) method developed in this study showed that the catalyst reaches the light-off temperature in a few seconds. The CEGI stops the ignition signal for a few seconds during the cranking period, so the unburned fuel-air mixture bypasses the combustion chamber and flows through the exhaust manifold. When the unburned mixture reaches two glow plugs installed upstream of the catalyst, it burns and releases the thermal energy to heat up the catalyst, In the FTP-75 vehicle tests, the CEGI showed that the exhaust emissions reduced by 47.7% for THC and by 88.6% for CO in the cold-transient phase of the test.

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Preparation of Novel Iron Phthalocyanine Containing Reactive Groups and its Deodorizing Property on Cellulose

  • Kim, Eun-Mi;Choi, Jae-Hong
    • Textile Coloration and Finishing
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    • v.25 no.4
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    • pp.247-253
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    • 2013
  • The enzyme-like catalytic functions of metal complex phthalocyanine derivatives those containing carboxylic acid groups could be applied as odor-removing systems and antibacterial systems. Pyromellitic dianhydride and 4-nitrophthalimide were used as starting material for synthesizing dinitro-tetracarboxylic acid iron phthalocyanine(compound 1). Then diamino-tetracarboxylic phthalocyanine(compound 2) was obtained by reduction of compound 1. For the formation of covalent bond with cellulose fiber, cyanuric chloride was introduced to the amino group of compound 2 by condensation reaction compound 3. The exhaustion method was employed for adsorbing compound 3 on cotton fiber. K/S values of each fabrics were measured by a CCM system and deodorizing rates were tested by a detector tube method for ammonia gas. K/S values of treated cotton fiber with compound 3 were arranged from 2.1 to 4.2 at $90^{\circ}C$ of exhaustion temperature. Deodorizing rates provided result of 81%, 84%, 88%, 91%, by passing time of 30 min, 60 min, 90 min, 120 min, respectively.

Experimental study on the reduction of CO and HC concentrations in the exhaust gas of gasoline engine by catalysts (촉매에 의한 가솔린 기관배기중 CO와 HC 농도저감에 관한 실험적 연구)

  • 조진호;서정일;조종철
    • Journal of the korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.46-55
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    • 1982
  • When an oxidizing catalytic converter which makes use of platium as a catalyst is employed by means if emission control of CO and HC gasoline engine, the effects of important factors for the purification efficiency, i.e engine speed and secondary air rate, on the reduction of CO and HC concentrations in the exhaust gas are studied experimentally. In the experiment, gasoline and LPG are used as a fuel, and the purification efficiency is examined and the results of both cases are compared with each other. The experimental results showed that the purification efficiency in the case of LPG is usually higher than that of gasoline, and the optimum values of engin speed and secondary air rate for maximum purification efficiency exist in common on both cases.

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NOx Reduction in Flue Gas Using Ammonia and Urea solution (암모니아와 요소용액을 이용한 배출가스내 질소산화물 저감 비교 평가)

  • 임영일;이정빈;유경선;김상돈
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1995.05a
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    • pp.236-239
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    • 1995
  • 50 kW$_{th}$ 용량의 기체연료버너에서 암모니아 기체와 요소용액을 이용한 선택적 무촉매 환원법 (SNCR;Selective Non-catalytic Reduction) 으로 질소산화물 (NOx) 저감에 관하여 연구하였다. 암모니아는 요소요액보다 더 낮은 반응온도에서 더 높은 효율을 보여주지만 경제성과 암모니아의 부식성 및 맹독성으로 인하여 취급하기에 곤란한 점이 있다. 반면에 요소용액은 적절한 액상첨가제와 기상첨가제를 사용하여 넓은 반응온도범위에서 높은 효율을 얻을 수 있으며 공정상의 조업비를 절감할 수 있다. 본 실험에서는 액상 첨가제인 $CH_3$OH 와 $C_2$H$_{5}$OH 을 사용하여 5$0^{\circ}C$ 정도의 최적반응온도 감소를 얻었으며 LPG 와 합성가스(CH$_4$:CO:H$_2$:$CO_2$=1:4:4:2) 틀 기상 첨가제로 사용하여 높은 질소산화물 저감 효율을 관찰하였다.

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Support Effects of Containing Catalysts on Methanol Dehydrogenation

  • Jung, Kwang-Deog;Joo, Oh-Shim
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1135-1138
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    • 2002
  • CuO/ZnO, CuO/SiO,sub>2, and CuO/ZrO2 catalysts were prepared for investigating the support effects on methanol dehydrogenation. It was found that the conversion of methanol was proportional to the copper surface area on Cu/ZnO cat alysts and was independent on that on Cu/ZrO2 and Cu/SiO2. The highest copper surface area was obtained with the Cu/ZrO2 (9/1). The unusual deactivation of the Cu/ZnO, which showed the highest selectivity among the catalysts tested, was observed. Pulse reaction with methanol indicated that the lattice oxygen in ZnO could be removed by forming CO2 in the catalytic reaction, supporting that the ZnO reduction was responsible for the severe deactivation of the Cu/ZnO.