• Title, Summary, Keyword: NOx(질소산화물)

Search Result 538, Processing Time 0.053 seconds

A Study for NOx Discharge Characteristics of Diesel Engines (디젤엔진의 NOx 배출 특성에 관한 연구)

  • 남정길;최주열
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.27 no.3
    • /
    • pp.373-380
    • /
    • 2003
  • According to the NOx regulations of annex Vi to IMO MARPOL 73/78, all diesel engines with a power output of more than 130 kW should be delivered so as to comply with the IMO speed dependent NOx limit. It is inevitable to adopt this regulations for marine engines Therefore, most of diesel engines which are being currently built should be designed and tested in accordance with the NOx technical code In this study, NOx concentrations of 4 type engines were measured with portable NOx measuring system recommended by ISO-8178. As the results NOx concentrations of each engine by variation of engine speed and engine load were visualized Also these results can be utilized for the basic design and development of diesel engine for NOx reduction.

Studies on NOx reduction by two-staged combustion and characteristics of N-release in pulverized coal combustion (탄연소시 N-release특성과 2단연소에 의한 NOx 저감에 관한 연구)

  • Hahn, Woong;Park, Chu-Sik;Kim, Sung-One;Choi, Sang-Il
    • 한국연소학회:학술대회논문집
    • /
    • /
    • pp.45-56
    • /
    • 2000
  • 미분탄 연소시 발생하는 질소산화물(NOx)은 석탄의 형태 및 등급에 따라 다르게 나타난다. 석탄에 함유되어 있는 질소 성분은 준역청탄인 경우 촤보다 휘발분에 많이 분포되어 있으며, 역청탄인 경우 촤에 많이 분포되어 있음을 확인하였다. 석탄에 함유되어 있는 질소의 분포에 따라 연속과정에 의해 최대로 발생할수 있는 질소산화물의 양과 질소산화물로 전환되는 정도를 예측할 수 있었다. NOx 방출은 석탄중에 함유되어 있는 질소성분의 양에 영향을 받으며, 고온 노출 시 방출되는 휘발성분의 양의 증가 그리고 공기비를 감소함으로서 질소산화물의 저감율을 증가시킬 수 있었다. 특히 질소산화물의 환원은 연료가 풍부한 조건에서 연소초기 고온으로 연소하는 경우 효과적이었다. 또한 2단 연소에 의한 방법으로 1단에서는 저공기비로 유지하고 2단에서 추가적인 공기를 공급함으로서 최종 공기비는 1.2인 조건에서 효과적으로 NOx를 저감할 수 있었다.

  • PDF

A Study on the Method of NOx Reduction and NOx Measurement for the Diesel Engines (디젤기관의 NOx 저감방법 및 NOx 측정에 관한 연구)

  • 남정길;김준효;최주열
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • /
    • pp.193-199
    • /
    • 2002
  • According to the NOx level requirement of annex Vl to IMO(International Maritime Organization) MARPOL 73/78, this regulation shall apply to each diesel engine with a power output of more than 130 ㎾ which is installed on a ship constructed and undergoes a major conversion on or after 1 January 2000. It is inevitable to adopt IMO standard for marine engines. Therefore, most of diesel engines which are being currently built should be tested and surveyed in accordance with the NOx technical code. In this study, various technics of NOx reduction methods were investigated for the diesel engines and the methods of NOx measuring were introduced by the new and simplified field detecting equipment. These results can be utilized for the basic design and developement of diesel engine for NOx reduction.

  • PDF

The Removal Properties of NOx with the Photocatalystic (TiO2)and UV Optical Science Reactions (광촉매(TiO2)와 UV의 광학반응을 이용한 질소산화물(NOx) 제거특성)

  • Lee, Kwan-Ho;Park, Woo-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.9
    • /
    • pp.3578-3582
    • /
    • 2010
  • The nitrogen oxidized substance(NOx) from cars in city is one of serious air-polution problems. In advanced country, the powder or the liquid photocatalystic for asphalt pavement and noise barrier have been used to reduce the air-polution. In this paper, the effect of photocatalystic on asphalt pavement has been evaluated, especially for UV optical science reactions analyzed NOx purification efficiencies of the automobile waste gas. Judging from the limited lab-scale test, the use of the powder or the liquid photocatalystic is one of alternatives to reduce the NOx from automobile.

A Study on NOx Removal Efficiency Depending on Electrode Configurations of Silent Discharges (무성방전 플라즈마 전극구조에 대한 질소산화물 제거효율 연구)

  • Hyung-Taek Kim;Young-Sik Chung;Myung-Whan Whang;Elena. A. Filimonova
    • Journal of the Korean Society of Safety
    • /
    • v.17 no.3
    • /
    • pp.112-117
    • /
    • 2002
  • A comparative investigation of an experimental and a simulation of chemical kinetics for NOx removal from silent(dielectric-barrier) discharges is presented. Several types of dielectric-barrier discharges were implemented depending upon the configuration of electrodes. The simulation was based on an approximate mathematical model for plasma cleaning of waste gas. The influence of non-uniform distributions of species due to the production of primary active particles in the streamer channel was taken into account. A comparison of observed experimental to the calculated removal efficiency of NOx showed acceptable agreement.

Experimental Study on the Long-term Performance of TiO2 Concrete for Road Structures (도로 구조물 적용을 위한 TiO2 콘크리트의 장기공용성에 대한 실험적 연구)

  • Lee, Jun Hee;Kim, Young Kyu;Lee, Seung Woo
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.35 no.3
    • /
    • pp.691-698
    • /
    • 2015
  • In the area of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides (NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide ($TiO_2$), that is one of photocatalytic reaction material, is very efficient for removing NOx. Therefore, application of $TiO_2$ concrete is a good alternative in order to remove NOx which is a main cause of air pollution. This experimental study aimed to evaluate the long-term performance of $TiO_2$ concrete such as NOx removal efficiency due to performance period and environmental resistance for application of road structures. It was found that the $TiO_2$ is reasonable applicable on the road structure because $TiO_2$ concrete has a long-term performance.

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
    • /
    • v.22 no.11
    • /
    • pp.1977-1983
    • /
    • 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.

  • PDF

Effect of Containing Promoter on SCR Catalysts (SCR 촉매에 포함된 조촉매 영향)

  • Seo, Choong-Kil
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.9
    • /
    • pp.474-481
    • /
    • 2018
  • The policy-making and technological development of eco-friendly automobiles designed to increase their supply is ongoing, but the internal combustion engine still accounts for approximately 95% of automobiles in use. To meet the stricter emission regulations of internal combustion engines based on fossil fuels, the proportion of after-treatments for vehicles and (ocean going) vessels is increasing continuously. As diesel engines have high power and good fuel economy in addition to less CO2 emissions, their market share is increasing not only in commercial vehicles, but also in passenger cars. Because of the characteristics of the diesel combustion, however, NOx is generated in localized high-temperature combustion regions, and particulates are formed in the zones of diffusion combustion. LNT and urea-SCR catalysts have been developed for the after-treatment of exhaust gas to reduce NOx in diesel vehicles. This study examined the effect of a containing promoter on SCR catalysts to cope with the severe exhaust gas regulation. The de-NOx performance of the Mn-SCR catalyst was the best, and the de-NOx performance was improved as the ion exchange rate between Mn ion and Zeolyst was good and the activation energy was low. The de-NOx performance of the 7Cu-15Ba/78Zeoyst catalyst was 32% at $200^{\circ}C$ and 30% at $500^{\circ}C$, and showed the highest performance. The NOx storage material of BaO loaded as a promoter was well dispersed in the Cu-SCR catalyst and the additional de-NOx performance of BaO was affected by the reduction reaction of the Cu-SCR catalyst. Among the three catalysts, the 7Cu-15Ba/Zeolyst SCR catalyst was resistant to thermal degradation. The same type of CuO due to thermal degradation migrates and agglomerates because BaO reduces the agglomeration of the main catalyst CuO particles.

Experimental Study on Reduction of Emissions for Marine Diesel Engines with a Double Post Injection (선박용 디젤엔진에서 이단지연분사에 따른 배기 배출물 저감에 관한 실험 연구)

  • Lee, Won-Ju;Choi, Jae-Hyuk;Cho, Kwon-Hae
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.39 no.4
    • /
    • pp.418-424
    • /
    • 2015
  • Marine Environment Protection Committee of the International Maritime Organization has decided to reinforce the NOx emission standards for ships passing an ECA(Emission Control Area) with Tier III standards from January 1, 2016. In this study, real-time measurements of the exhaust gas, cylinder pressure and fuel consumption were conducted at each load of a T/S Hanbada main engine of Korea Maritime and Ocean University, which is controlled by single injection and double post injection for reducing NOx emissions. The results showed that the quantity of CO2 and NOx increased in proportion to the engine load, whereas the CO concentration was inversely proportional to the engine load. In addition, double post injection decreased 10 % of P-max and reduced 25~30 % of the NOx emissions compared to single injection, whereas there was a trade-off relation, such as increase 3~5 % of SFOC (Specific Fuel Oil Consumption).

DeNOx Characteristics of Hybrid SNCR-SCR Process in a Pilot Scale Flow Reactor (파일럿 규모 반응기에서 Hybrid SNCR-SCR 공정의 질소산화물 저감 특성)

  • Eom, Won-Hyun;Yoo, Kyung-Seun;Kim, Sung-June
    • Korean Chemical Engineering Research
    • /
    • v.49 no.1
    • /
    • pp.89-94
    • /
    • 2011
  • DeNOx characteristics of hybrid SNCR-SCR process have been investigated in a pilot scale flow reactor. DeNOx efficiency of SNCR reaction was about 80% at $970^{\circ}C$ and hybrid SNCR-SCR process showed 92% at $940^{\circ}C$ with NSR = 2.0. Compared to SNCR process alone, hybrid SNCR-SCR process was more effective at cool side, which is lower than $940{^{\circ}C}$. It should be also noted that ammonia slip from hybrid SNCR-SCR process was below 1ppm at the condition of higher space velocity and the required catalyst volume can be decreased to 2/3 of SCR process. Key factors for DeNOx efficiency of hybrid SNCR-SCR process were found to be $NH_3$ concentration and NOx selectivity of urea injected in SNCR process.