• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.83-90
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• 2004

Plasma/catalyst combined reactor was designed to overcome the limits of plasma and catalyst technologies. Optimum reductant and catalyst was selected from screening test. Experiments about the concentrations of reactant and $H_2O$ and the effect of temperature were carried out. Hydrocarbons with double bond such as propylene and so on were more reactive than any other reductants in plasma/catalyst condition. Photocatalyst, especially hombikat >$TiO_2$ with the largest surface area among the catalysts tested, showed the highest DeNOx efficiency in plasma/catalyst reaction. As the concentration of $H_2O$ increased, the removal of NO was enhanced. The increased concentration of >$O_2$ promoted the reaction of NO which was oxidized to$NO_2$.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.99-105
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• 2001

For the design of selective catalytic reactors of NOx by $NH_3$, engineering approach can be performed to determine the reactor shape, mixing device and $NH_3$ injection system. This study shows the optimization of guide vanes to improve the flow pattern near the catalyst layer of SCR in a untility boiler. By varying their spacings and shapes, flow performance of guide vanes was analyzed to achieve an uniform velocity distribution which increases the NOx convesion efficiency, and a flow direction normal to the layer which minimises the erosion by the dust in the flue gas. Including these results, experimental and numerical studies for the SCR design were discussed.

• 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 Korean Nuclear Society Conference
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• 1995.05a
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• pp.818-823
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• 1995

방사성 폐기물 소각로에서 발생하는 off-gas중에는 NOx가 포함되어 있으며 이를 제어하기 위하여 NOx 배출의 재어에 효과적이라고 알려진 SCR법을 사용하여 실험을 행하였다. NOx 방출 저감화를 위해 상업화된 다양한 촉매들 중에서 V$_2$O$_{5}$, MoO$_3$ Fe$_2$O$_3$ 그리고 SnO$_2$를 TiO$_2$honeycomb형태의 담체에 담지시켜 제조한 촉매들의 특성을 조사하고 여러 변수들, 예를 들면 촉매의 종류, 담체의 종류, 반응온도, feed의 조성 등이 반응특성에 미치는 영향을 실험실 규모의 반응기에서 조사하였다. 10%V$_2$O$_{5}$TiO$_2$촉매가 35$0^{\circ}C$에서 94.4%의 높은 NO-$N_2$전환율을 보였으며 열적 안정성이 높은 SnO$_2$나 MoO$_3$의 첨가는 높은 전환율을 보이는 온도 범위를 확장시켜 주었다.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1013-1018
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• 2008

Vortex Inertial Staged Air (VIStA) burner for an once-through type boiler has been restored to the original premixed type to reduce nitrogen oxide (NOx) emission. The premixed version yields additional de-NOx effect by 20 ppm. The flame is formed closer to the wall at the 1st stage combustion chamber compared with the non-premixed one. The combustion characteristics are more sensitive to the air distribution for the premixed type, which necessitates proper optimization.

• 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.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.15-17
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• 2008

저온 플라즈마를 이용한 탈황탈질 시스템은 한 개의 반응기에서 오염물질을 동시에 제거함으로써 설비가 매우 compact하고 운전비가 저렴한 장점을 가지고 있다. 본 논문은 펄스 고전압 방전에 의한 저온플라즈마를 이용하여 Sox, Nox동시 제거를 위한 전원장치의 회로 구성과 전원장치의 동작특성을 설명하였다. 그리고 당사의 탈황탈질 시스템 기술현황 및 향후계획을 논의하였다.

• 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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.283-290
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• 2010

The main goal of this study is to examine the use of a hybrid -fuel lean reburning system with air staging for $NO_X$ reduction. The experimental variables include the reburn fuel fraction, sizes of reburn- fuel-injection nozzles, oxygen enrichment ratio, and location of reburn- fuel- injection. The effect of the flow field induced by air- staging combustion on $NO_X$ reduction is considered, and then, the $NO_X$ reduction rate is compared with only fuel lean reburning system. On the basis of the effectiveness of each De-$NO_X$ process, the advantage of using the hybrid reburning system with air staging is determined and discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.118-118
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• 1996