• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.499-502
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• 2001

In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using cylinder type reactor and packed-bed reactor. An experimental investigation has been conducted for NO concentration of 50[ppm], 100[ppm], 200[ppm] balanced with air, a gas flow rate of 5[1/min]. Ac voltage to discharge the gases was supplied. In the result, NOx removal rate in packed bed reactor is higher than that in cylinder type reactor. it is thought that plasma density in contact point of BaTiO$_3$ is significantly higher than that in cylinder reactor.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.462-464
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• 1995

In this paper, experiments were carried out to study the decrease of NOx in simulated flue gases (initial concentration of NO 1000, 750, 400 ppm, : $N_2$ balance gas). Characteristics of NOx reduction are measured and analysed in corona discharge of multi needles to plane electrode structure and magnetic field. The best characteristics of NO reduction is measured when electric and magnetic field were supplied to reactor, at same time. Consumption power applied electric and magnetic field were higher than that of discharge applied only electric field.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.27-32
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• 1999

This study identified concentrations of all pollutants emitted from idling of vehicles such as cars, taxis, trucks, and buses. In this investigation we analyzed concentrations of $SO_2$, NOx, CO, and $CO_2$ omitted from exhaust pipe of vehicles as a function of vehicle type, mileage, exhaust volume, and fuel type using the GreenLine. Compact or light cars, which have relatively low exhaust volume, showed much higher exhaust concentrations of $CO_2$, CO, and NOx than those emitted from vehicles with high exhaust volume. Vehicles using light oil showed much higher exhaust NOx concentrations than those of vehicles using gasoline. Vehicles using LPG and compact cars showed very high exhaust CO concentration compared to other vehicles. NOx exhaust concentrations were increased with increasing the mileage of vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.95-105
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• 2012

The selective catalytic reduction (SCR) system is a highly-effective aftertreatment device for NOx reduction of diesel engines. Generally, the ammonia ($NH_3$) was generated from reaction mechanism of SCR in the SCR system using the liquid urea as the reluctant. Therefore, the precise urea dosing control is a very important key for NOx and $NH_3$ slip reduction in the SCR system. This paper investigated NOx and $NH_3$ emission characteristics of urea-SCR dosing system based on model-based control algorithm in order to reduce NOx. In the map-based control algorithm, target amount of urea solution was determined by mass flow rate of exhaust gas obtained from engine rpm, torque and $O_2$ for feed-back control NOx concentration should be measured by NOx sensor. Moreover, this algorithm can not estimate $NH_3$ absorbed on the catalyst. Hence, the urea injection can be too rich or too lean. In this study, the model-based control algorithm was developed and evaluated on the numerical model describing physical and chemical phenomena in SCR system. One channel thermo-fluid model coupled with finely tuned chemical reaction model was applied to this control algorithm. The vehicle test was carried out by using map-based and model-based control algorithms in the NEDC mode in order to evaluate the performance of the model based control algorithm.

• Journal of Power System Engineering
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• v.21 no.6
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• pp.68-78
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• 2017

Major countries have tighten their NOx regulation of diesel passenger cars. In the case of the EU, the regulation has been toughen up to 6.25 times since 2000. Despite the regulation the NOx concentration of the ambient has not been reduced proportionally. Futhermore, some manufacturers were disclosed using a defeat device for meeting the regulation illegally. As these issues, to reduce NOx emission practically, Korea and the EU introduced the real-world driving emission(RDE) regulation and the test method that will be applied after 2017. Also, the US has used the test equipment(PEMS) to detect a defeat device. In this paper, for the regulation to make a soft landing in Korea, 4 diesel passenger cars which met Euro 6a~6b regulation and were equipped with LNT/SCR were tested at a chassis dynamometer with environmental chamber applying the off-cycles(FTP, US06, SC03, HWFET and CADC) and several ambient condition(-7 and $14^{\circ}C$) as well as certification mode(NEDC, WLTC@ $23^{\circ}C$). The result of the test showed that the ambient temp. and the engine load as a test mode impacted the NOx emission of the cars while the vehicles with SCR emitted NOx lower than with LNT. Additionally, to propose an effective RDE test method, the above result was compared with the results of the other papers which tested RDE using the same cars.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.53-61
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• 2016

Unburned Carbon(UBC) and NOx emissions from High-moisture coal and Dried coal were investigated in Drop Tube Furnace(DTF). When the same amount of the High-moisture coal and Dried coal were oxidized in DTF, the results show that UBC and NOx emissions of Dried coal case is higher than High-moisture coal case. As the moisture in coal decreases from 40% to 10%, the average gas temperature increases but the moisture concentration in DTF decreases. As the wall temperature increases from $900^{\circ}C$ to $1500^{\circ}C$, the UBC decreases and NOx emissions increases. Especially, the difference for UBC between High-moisture coal and Dried coal decreases with increasing wall temperature.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.27-33
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• 2004

The catalytic effect of waterworks sludge on NOx removal in $BaTiO_3$pellets and sludge pellets combined packed-bed plasma reactor with plate-plate electrode geometry is measured for the various conditions. NOx removal rate is about 90[%] at $BaTiO_3$-sludge combined reactor used fresh sludge. $NO_2$ and $O_3$ as byproducts are significantly generated in only $BaTiO_3$ packed-bed plasma reactor, however, in $BaTiO_3$-sludge combined packed-bed reactor, $NO_2$ and $O_3$ are completely removed while $CO_2$ as by-products are observed from FTIR spectra. $NO_2$ and $O_3$ seem to react with metallic molecules, metal oxide, and organic compounds that are generally chlorophyll included in sludge. NOx removal rate increases with $O_2$ concentration increasing. Removal rates $NO_2$ and $O_3$ are independent of operating time and repetition measurement times.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.488-496
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• 2017

Emissions of pollutants from ship-based sources are controlled by the International Maritime Organization (IMO). Since pollutants emitted from ship may be dispersed to the land, controlling emissions from ships is necessary for efficient air quality management in Incheon, where exposure to ship-based pollution is frequent. It has been noted that the ratios of air pollutant emissions from coastal areas to inland areas are about 14% for NOx and 10% for SOx. The air quality of coastal urban areas is influenced by the number of ships present and the dispersion pattern of the pollutants released depending on the local circulation system. In this study, the dispersion of pollutants from ship-based sources was analyzed using the numerical California Puff Model (CALPUFF) based on a meteorological field established using the Weather Research and Forecasting Model (WRF). Air pollutant dispersion modeling around coastal urban regions such as Incheon should consider point and line sources emitted from both anchored and running ships, respectively. The total average NOx emissions from 82-84 ships were 6.2 g/s and 6.8 g/s, entering and leaving, respectively. The total average SOx emissions from 82-84 ships, entering and leaving, were 3.6 g/s and 5.1 g/s, respectively. The total average emissions for NOx and SOx from anchored ships were 0.77 g/s and 1.93 g/s, respectively. Due to the influence of breezes from over land, the transport of pollutants from Incheon Port to inland areas was suppressed, and the concentration of NOx and SOx inland were temporarily reduced. NOx and SOx were diffused inland by the sea breeze, and the concentration of NOx and SOx gradually increased inland. The concentration of pollutants in the area adjacent to Incheon Port was more influenced by anchored ship in the port than sea breezes. We expect this study to be useful for setting emission standards and devising air quality policies in coastal urban regions.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.511-521
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• 2000

Investigation was carried out lean burn de-NOx properties of Pt-$TiO_2$ bifunctional catalyst by propylene in order to get the high de-NOx activity and the wide temperature window under coexistence of $SO_2$ and $H_2O$. Only noncatalyst and carrier catalyst themselves had NOx conversion activity at high temperature over $400^{\circ}C$. NOx conversion activity of catalysts exchanged copper ion resulted in Cu-$TiO_2$>Cu-ZSM-5>Cu-$Al_2O_3$>CU-YZ>Cu-AZ. Catalysts impregnated with platinum based on titania gave the results of high NOx conversion activity at low temperature. $250^{\circ}C$. Bifunctional catalysts based on Pt-$TiO_2$ showed high NOx conversion activity both at a low zone of $300^{\circ}C$ and a high zone of $500^{\circ}C$. Pt-$TiO_2$/$Al_2O_3$ catalyst gave the highest NOx conversion activity at a low temperature zone. and Pt-$TiO_2$/$Mn_2O_3$(21) catalyst gave the highest NOx conversion activity at a high temperature zone. Under the coexistence of $SO_2$ and $H_2O$. NOx conversion activities of 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 catalyst was high both at a low and high temperature zone, and increased depending on oxygen concentration. 0.55wt%Pt-$TiO_2$/5wt%Cu-ZSM-5 catalyst showed the best correlation between de-NOx activities and the propyl ere conversion rates to CO on the log function.

• Journal of Environmental Science International
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• v.15 no.6
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• pp.601-606
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• 2006

The coal gasification fuel is important to replace petroleum fuel. Also they have many benefits for reducing the air pollution. Measurements on the combustion characteristics of synthetic gas from coal gasification have been conducted as compared with LPG in constant volume combustion chamber. The fuel is low caloric synthetic gas containing carbon monoxide 30%, hydrogen 20%, carbon dioxide 5%, and nitrogen 45%. To elucidate the combustion characteristics of the coal gasification fuel, the combustion pressures, combustion durations, and pollutants(NOx, $CO_2$, CO) are measured with equivalence ratios($\phi$), and initial pressures of fuel-air mixture in constant volume chamber. In the case of the coal gasification fuel, maximum combustion pressure and NOx concentration are lower rather than LPG fuel. However CO and $CO_2$ emission concentration are similar to that of LPG fuel.