• Title/Summary/Keyword: Automobile exhaust catalyst

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An Experimental Study on Exhaust Gas Reduction of Diesel Oxidation Catalyst by CVS-75 Mode in Light Duty Diesel Engine (小型디젤機關에서 CVS-75 모드에 따른 디젤 酸化觸媒裝置의 排出가스 低減에 關한 實驗的 硏究)

  • 한영출;김종춘;오용석
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.4
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    • pp.457-461
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    • 1999
  • Recently, increasing usage of diesel vehicle, many countries try to reduce the pollutant materials by emission regulation standard. Particularly, in our country, the supplement ratio of diesel vehicle is high, and air pollution by particulate matter(PM) is very serious. So, in theoretical study wer analyzed the formation principle of gaseous emission and PM, the characteristics of CVS-75 mode. In experimental study, we tested exhaust gas reduction of emission and PM, the characteristics of CVS-75 mode. In experimental study, we tested exhaust gas reduction of disel oxidation catalyst(DOC) by CVS-75 mode in light duty diesel vehicle. In case of an automobiletest with the 2,956cc diesel engine which DOC was equipped, CVS-75 mode which is similar to driving conditions on the road was chosen as the restrictive mode of light duty diesel automobile in our country. According to the Pt, the reduction rate of exhaust emission was estimated with using 0.1% high sulfur fuel and 0.05% low sulfur fuel.

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EXPERIMENTAL APPROACH FOR EVALUATING EXHAUST FLOW DISTRIBUTION FOR PZEV EXHAUST MANIFOLDS USING A SIMULATED DYNAMIC FLOW BENCH

  • Hwang, I.G.;Myung, C.L.;Kim, H.S.;Park, S.
    • International Journal of Automotive Technology
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    • v.8 no.5
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    • pp.575-581
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    • 2007
  • As current and future automobile emission regulations become more stringent, the research on flow distribution for an exhaust manifold and close-coupled catalyst(CCC) has become an interesting and remarkable subjects. The design of a CCC and exhaust manifold is a formidable task due to the complexity of the flow distribution caused by the pulsating flows from piston motion and engine combustion. Transient flow at the exhaust manifold can be analyzed with various computational fluid dynamics(CFD) tools. However, the results of such simulations must be verified with appropriate experimental data from real engine operating condition. In this study, an experimental approach was performed to investigate the flow distribution of exhaust gases for conventional cast types and stainless steel bending types of a four-cylinder engine. The pressure distribution of each exhaust sub-component was measured using a simulated dynamic flow bench and five-hole pitot probe. Moreover, using the results of the pitot tube measurement at the exit of the CCC, the flow distribution for two types of manifolds(cast type and bending type) was compared in terms of flow uniformity. Based on these experimental techniques, this study can be highly applicable to the design and optimization of exhaust for the better use of catalytic converters to meet the PZEV emission regulation.

An Experimental Study on the Reduction of Nitric Oxides from the Diesel Engine Exhaust Gas with Metal Supported Oxides Catalysts (디젤엔진 배기가스중 질소산화물 저감을 위한 금속 산화물 촉매를 이용한 실험적 연구)

  • Chae, Jae-Ou;Hwang, Jae-Won;Jung, Jee-Yong;Han, Jung-Hee;Hwang, Hwa-Ja;Kim, Seok;Eduard, Mikholap
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.3
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    • pp.68-75
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    • 2001
  • In this paper, a number of supported metal oxides and perovskite type catalysts were investigated for the NOx reduction from the diesel engine exhaust gas. All catalysts were made into pellets type with diameter of 3-4 mm alumina(Al$_2$O$_3$) as a supporter. These samples were tested by real diesel exhaust gas which contains CO, hydrocarbons and soot in the temperature range of 150~55$0^{\circ}C$ with the $3300h^{-1}$ space velocity (SV). Among the results, several promising catalysts showed NOx conversion above 50% in the temperature range of 150-35$0^{\circ}C$. From these results supported metal oxides catalysts and perovskite type could be recommended for the practical application to the automobile exhaust treatments.

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Characteristics of Simultaneous Removal of NOx and PM over a Hybrid System of LNT/DPF + SCR/DPF in a Single Cylinder Diesel Engine (단기통 디젤엔진에서 LNT/DPF + SCR/DPF 하이브리드 시스템의 NOx 및 PM 동시저감 특성)

  • Kang, Wooseok;Park, Su Han;Choi, Byungchul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.2
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    • pp.152-160
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    • 2016
  • The market demand for diesel engine tends to increase in general passenger cars as well as commercial vehicles because of its advantages. However, to meet the vehicle emissions regulation which will be more stringent in the future, it is necessary to plurally apply all after-treatment technologies such as diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), lean NOx trap (LNT) and selective catalytic reduction (SCR), and so on. Accordingly, the exhaust after-treatment system for diesel vehicle requires the technology of minimizing the numbers of catalysts by integrating every individual catalysts. The purposes of this study is to develop hybrid exhaust after-treatment device system which simultaneously uses LNT/DPF and SCR/DPF catalyst concurrently reducing NOx and particulate matter (PM). As the results, the hybrid system with $NH_3$ generated at LNT/DPF working as a reducing agent of SCR/DPF catalyst, improving NOx conversion rate, was found to be more excellent in de-NOx performance than that in LNT/DPF alone system.

Status and Strategy on Recycling of Domestic Used Chemical Catalysts (국내 사용 후 화학촉매제품의 재자원화 현황 및 향후 방향)

  • Kim, Young-Chun;Kang, Hong-Yoon
    • Resources Recycling
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    • v.26 no.3
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    • pp.3-16
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    • 2017
  • Chemical catalyst products are applied to various fields such as petrochemical process, air pollution prevention facility and automobile exhaust gas purifier. The domestic and overseas chemical catalyst market is increasing every year, and the amount of waste catalyst generated thereby is also increasing. Most of the used chemical catalyst products, such as desulfurized waste catalysts and automobile waste catalysts containing valuable metals are important recyclable resources from a substitute resource point of view. The recycling processes for recovering valuable metals have been commercialized through some urban mining companies, and SCR denitration catalysts have been recycled through some remanufacturing companies. In this paper, the amount of domestic production and recycling of major catalyst products have thus been investigated and analyzed so as to be used as basic data for establishing industrial support policy for recycling of used chemical catalyst products. Also tasks for promoting the recycling of used chemical catalyst products are suggested.

Experimental Study on Mixing Efficiency of Exhaust Gas and Reductant According to SCR Mixer Shape (SCR 믹서형상에 따른 배기가스와 환원제 혼합 효율에 관한 실험적 연구)

  • Choe, Munseok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.74-79
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    • 2021
  • This study examined the mixing efficiency of exhaust gas and urea according to the mixer shape in the SCR system. For the experiment, an SCR simulation system was manufactured, and a uniformity detector was attached to the catalyst location to measure the uniformity. The experiment was conducted by setting the exhaust-gas flow rate, temperature, mixer type, and catalyst distance as variables. The experimental results confirmed the swirl angle analysis, urea number distribution, and uniformity. The swirl angle experiment of Models A and B confirmed that the swirl angle of Model A was formed approximately 7 to 8 degrees higher over the entire RPM range. When there was no mixer in the SCR system, the urea and water were concentrated to one side. Mixer Model A showed an even distribution overall, and Model B showed a slightly concentrated tendency at the beginning but then showed a stable distribution of urea. The mixing efficiency of 90%, which was the uniformity target, could be satisfied in Model A and Model B. In particular, Model A showed excellent results that satisfied 90% efficiency at 10 cm of the catalyst position.

Parameter Study of Exhaust Pressure in Catalytic Converter (촉매를 고려한 배압 계산에서의 인자 결정 연구)

  • 이원근;임효재
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.77-82
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    • 2003
  • A parametric study was conducted on pressure drop in a catalytic converter for automobile. In this work, we proposed a new pressure drop relation which contains the various parameters needed to calculate and got a few results. In a monolith of catalyst, the flow originally turbulent flow changes to laminar flow and thus the pressure drop through the monolith is linearly proportional to the velocity. The exhaust pressure is doubly affected by the increase of mean velocity and length when we decrease the diameter of monolith while the volume keeps constant. Theoretical parameters such as $\alpha$ and $\beta$ are suggested to use as a reference value when there is no a experimental data. Especially in the part load test, these values should be modified to consider the property change of exhaust gas.

Numerical Study on the Injector Shape and Location of Urea-SCR System of Heavy-duty Diesel Engine for Preventing $NH_3$ Slip (대형 디젤엔진용 SCR 시스템의 암모니아 슬립 억제를 위한 인젝터의 형상 및 위치에 관한 수치적 연구)

  • Jeong Soo-Jin;Lee Sang Jin;Kim Woo-Seung;Lee Chun Beom
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.1
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    • pp.68-78
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    • 2006
  • In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia$(NH_3)$ in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates the DeNOx process. Moreover, a mobile SCR system has only a short distance between engine exhaust and the catalyst entrance. Hence, this leads to not enough residence times of urea, and therefore evaporation and thermolysis cannot be completed at the catalyst entrance. This may cause high secondary emissions of Ammonia and isocyanic acid from the reducing agent and also leads to the fact that a considerable section of the catalyst may be misused for the purely thermal steps of water evaporation and thermolysis of urea. Hence the key factor to implementation of SCR technology on automobile is fast thermolysis, good mixing of Ammonia and gas, and reducing Ammonia slip. In this context, this study performs three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various injection pressure, injector locations and number of injector hole. This study employs Eulerian-Lagrangian approach to consider break-up, evaporation and heat and mass-transfer between droplet and exhaust gas with considering thermolysis and the turbulence dispersion effect of droplet. The SCR-monolith brick has been treated as porous medium. The effect of location and number of hole of urea injector on the uniformity of Ammonia concentration distribution and the amount of water at the entrance of SCR-monolith has been examined in detail under various injection pressures. The present results show useful guidelines for the optimum design of urea injector for reducing Ammonia slip and improving DeNOx performance.

Effect of Gasoline Property Change on Exhaust Gas and Catalyst (휘발유 물성변화에 따른 배출가스 및 촉매에 미치는 영향성 연구)

  • Noh, Kyeong-Ha;Kim, Sung-Woo;Lee, Min-Ho;Kim, Ki-Ho;Lee, Jung-Min
    • Journal of Power System Engineering
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    • v.22 no.6
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    • pp.67-73
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    • 2018
  • Gasoline that meets the quality standards is distributed in Korea. However, consumers who use toluene or solvent mixed with gasoline have appeared due to rising crude oil prices and for the purpose of tax evasion. Gasoline quality standard is enacted by the domestic and international research reference. A wrong fuel can influence automobile performance or environmental issue. Thus, empirical data from this issue is necessary. Therefore, this research observed catalyst influence by gasoline property change and inspect influence of environment. In this study, fuel property evaluation, lean-burn evaluation, and real vehicle exhaust emission test were performed. In the result of fuel property, the fuel "A" was measured to be up to 27% less octane than the normal gasoline and the distillation property was measured 24% higher than normal gasoline. In the test result of single cylinder engine lean-burn test, the fuels "A" and "B" show torque value 20% less than the normal gasoline. As a result of vehicle test using the catalyst, the fuel "A" was increased more than the normal gasoline with 83% THC, 1,806% CO and 128% NOx, and the fuel "B" was increased more than normal gasoline with 1.6% THC, 391% CO and 142% NOx.