• Title/Summary/Keyword: Nitrogen Oxides

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An Emission Characteristics of a Controlled Auto-Ignition Gasoline Engine according to Variation of the Air-Fuel Ratio (공기연료비의 변화에 따른 제어자발화 가솔린기관의 배기 특성)

  • Kim, Hong-Wung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.2
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    • pp.79-85
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    • 2004
  • This work treats a controlled auto-ignition (CAI) single cylinder gasoline engine, focusing on the extension of operating conditions. Investigated are the engine emission characteristics under the wide range of operating conditions such as 32 to 63 in the air-fuel ratio, 1000 to 1800 rpm in the engine speed, and 150 to $180^{\circ}C$ in the inlet-air temperature. A controlled auto-ignition gasoline engine can be achieved the ultra lean-burn with self-ignition of gasoline fuel by heating inlet air. It can be achieved that the emission concentrations of carbon monoxide, hydrocarbons and nitrogen oxides had been significantly reduced by CAI combustion compared with conventional spark ignition engines.

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A Study on the Emission Factors of Air Pollutants for the Melting Furnaces of the Iron and Steel Industry (철강산업 용융로의 대기오염물질 배출계수 산정 연구)

  • 석광설;방선애;홍지형;이석조;김대곤;이대균;허정숙;이은정
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.4
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    • pp.571-578
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    • 2004
  • The purpose of this study is to estimate of emission factors of the air pollutants for the melting furnaces for the iron and steel industry. The result of this study is able to obtaine the emission factor of particulate matters (PM), sulfur dioxide. nitrogen oxides for melting furnace. The emission factors of each pollutants were as follows : - the emission factor varied between 6.13E-03~6.12E-01 kg/ton for PM -1.59E-01~2.45E+00kg/ton for $SO_2$ - 6.82E-02~6.88E-01 kg/ton for NOx, respectively. Analysis of the differences in the emission factors of ours and U.S. EPA's yielded the following results for the Wilcoxon method : p>0.05. The statistical analysis showed no differences in the our emission factors and U.S. EPA's

The Effect of Activated Carbon Fiber on the Shelf Life of the Propellants (추진제 저장수명에 미치는 활성탄소섬유의 영향)

  • Yoon Keun-sig;Lee Jong-chan
    • Journal of Applied Reliability
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    • v.5 no.3
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    • pp.343-355
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    • 2005
  • As the propellants decompose, they release nitrogen oxides which reduce the shelf life of the propellants by accelerating decomposition rate. The activated carbon fiber was used to extend the shelf life of the propellants that was stockpiled by the military. It is found that the activated carbon fiber adsorbs the nitrogen oxides which were produced by spontaneous reaction of the propellants. As a result, the activated carbon fiber extend the shelf life of the propellants by reducing decomposition rate of the propellants. If 20g of propellant store with 2g of activated carbon fiber, the shelf life of the propellants can be lengthened by 1.4 times.

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A Study on the Emission Characteristics of NOx in Medium Speed Diesel Engine (중속 디젤기관의 질소산화물 배출특성에 관한 연구)

  • 우석근;윤건식;윤영환
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.4
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    • pp.526-534
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    • 2000
  • In this study, the characteristics of exhaust emissions in medium speed diesel engine under various operating conditions were investigated through experiments to derive the optimum conditions for minimizing the exhaust emissions, especially, nitrogen oxides. The 355 KW$\times$1200 rpm medium speed diesel engine was intensively examined to investigate the trend of exhaust emissions in case that the parameters affecting combustion conditions such as fuel injection timing, intake air temperature and pressure, engine speed and load were changed. The exhaust emissions for 9 sets of medium speed diesel engine were analyzed in addition. From this study, NOx level could be reduced by 30~50% through the adjustment of retarded fuel injection timing, lowered intake air temperature and increased charging air pressure.

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Propellant Shelf-life Extension by Surface-modified Activated Carbon Fiber (활성탄소섬유를 이용한 추진제 저장수명 연장)

  • Yoon, Keun Sig;Lee, Young Seak;Ryu, Seung Kon
    • Korean Chemical Engineering Research
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    • v.49 no.4
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    • pp.443-448
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    • 2011
  • The propellant has a short shelf-life because of nitrogen oxides that were released from nitrocellulose decomposition. As-received and surface-modified ACFs were applied to remove the nitrogen oxides with intend to extend the shelf-life of propellant. The specific surface area of modified ACFs was slightly decreased but nitrogen function groups such as pyridine, pyridone and pyrrol were created on the surface of ACFs. As a result, the NO removal capacity of the surface-modified ACF by propellant waste increased about twice than that of the as-received ACF. The shelf-life of propellant was extended about 1.25 times by accompanying surface-modified ACF.

Reduction of Nitrogen Oxides with Diesel Oil In Pilot Scale SCR(Selective Catalytic Reduction) Process (파일럿규모의 선택적촉매환원장치에서 디젤유를 이용한 질소산화물 제거)

  • Lee, In-Young;Yoo, Kyong-Ok
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.11
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    • pp.1977-1983
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    • 2000
  • SCR(selective catalytic reduction) pilot plant for reduction of the nitrogen oxides using diesel oil as a reductant was installed at the NG(natural gas) fired combined cycle and the activity of Pt(0.3%)/Zeolite catalyst was studied in real flue gas condition according to the amount of reductant. reaction temperature and space velocity. NOx conversion gradually increased with increasing the diesel oil concentration up to C/N ratio 5.5(C/N ratio: the ratio of the number of carbon atom to the number of NOx molecules included in the flue gas). Increasing the reaction temperature. NOx conversion increased and reached a maximum conversion of 50% at $190^{\circ}C$. NOx conversion did not changed with increasing the space velocity up to 18,500/hr and then gradually decreased. These results reveal the potential for diesel oil as a reductant for de-NOx SCR process.

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