• 한국대기환경학회지
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• 제14권5호
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• pp.455-464
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• 1998

Removal teals of Soxmox were performed using low density ceramic filters doped with various catalysts. Disc type (50 mmO.Dx10 mmt) low density ceramic filters were doped with three different catalysts such as Cu to remove SOx and NOx, and Mn and Co to remove NOx. The air permeabilities and specific surface areas were 40~50cc/min.cm2.cmH2O and 4.1~8.88 m2/g, respectively. Also, the peak pore sizes of catalyst support were 3~5nm. Tests were focused to search optimum operating temperatures for different catalysts. It was found that as the CuO content increases, SOx removal efficiency was increased. NOx removal efficiencies for Mn, Cu and Co, were 85% at 30$0^{\circ}C$, 90% at 40$0^{\circ}C$ and 90% at 45$0^{\circ}C$, respectively.

• 한국도로학회논문집
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• 제16권5호
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• pp.49-58
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• 2014

PURPOSES : In areas 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. The NOx removing mechanism of $TiO_2$ is the reaction of solar photocatalysis. Therefore, $TiO_2$ in road structure concrete need to be contacted with ultraviolet rays (UV) to be activated. In general, $TiO_2$ concretes are produced by replacement of $TiO_2$ as a part of concrete binder. However, considerable portion of $TiO_2$ in concrete cannot contact with the pollutant in the air and UV. Therefore, $TiO_2$ penetration method using the surface penetration agents is attempted as an alternative in order to locate $TiO_2$ to the surface of concrete structure. METHODS : This study aimed to evaluate the NOx removal efficiency of photocatalytic concrete due to various $TiO_2$ application method such as mix with $TiO_2$, surface spray($TiO_2$ penetration method) on hardened concrete and fresh concrete using surface penetration agents. The NOx removal efficiency of $TiO_2$ concrete was confirmed by NOx Analyzing System based on the specification of ISO 22197-1. RESULTS : The NOx removal efficiency of mix with $TiO_2$ increased from 11 to 25% with increasing of replacement ratio from 3 to 7%. In case of surface spray on hardened concrete, the NOx removal efficiency was about 50% due to application amount of $TiO_2$ with surface penetration agents as 300, 500 and 700g/m2. The NOx removal efficiency of surface spray on fresh concrete due to all experimental conditions, on the other hand, which was very low within 10%. CONCLUSIONS : It was known that the $TiO_2$ penetration method as surface spray on hardened concrete was a good alternative in order to remove the NOx gases for concrete road structures.

• 공업화학
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• 제20권4호
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• pp.437-442
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• 2009

$TiO_2$, $Al_2O_3$를 담체로 한 Pt계 촉매에서 NOx, soot의 동시 제거 반응과 촉매의 열충격에 대한 연구를 수행하였다. 실험은 NOx와 soot의 반응을 독립 또는 동시에 반응시킨 조건으로 수행하였으며 그 결과 담체의 종류 및 상에 따라서 서로 상이한 NOx 제거능력과 soot 산화력을 나타내었고, soot의 산화시작온도의 결정은 NOx 제거능력과 상관관계가 있었다. NOx, soot의 동시 반응 시에는 생성된 $NO_2$에 의하여 soot 산화시작온도가 저온으로 이동하였다. 또한 열충격에 대한 NOx 제거율은 Pt/$Al_2O_3$ 촉매가 Pt/$TiO_2$ 촉매에 비하여 효율저하가 적게 일어났으며 soot 산화력은 활성점인 Pt의 소결현상에 의하여 촉매에 관계없이 모두 감소하였다.

• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.830-835
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• 1997

In this study an experimental investigation has been conducted to remove NOx and SO$_2$simultaneously from a combustion flue gases were consisted of NO-SO$_2$-$CO_2$-$N_2$-O$_2$([NO]o:200ppm and [SO$_2$]o:800ppm) and the injection gases used as radical source gases were NH$_3$-Ar-air and CH$_4$-Ar-air. NOx and SO$_2$removal efficiency and the other by-products were measured by Fourier Transform Infrared(FTIR) as well as SO$_2$, NOx and NO$_2$gas detectors. and SEM images after sampling. The results showed that a significant Nucleating Particle Counter(CNPC) and SEM images after sampling. The results showed that a significant aerosol particle formation was observed during a simultaneous NOx and SO$_2$removal operation in corona radical shower systems. The diameter of aerosol particles was in the range of 0.18 to 3.6${\mu}{\textrm}{m}$ with a maximum fraction of particles at particles diameter of 1${\mu}{\textrm}{m}$. The NOx removal efficiency significantly increased with increasing applied voltage and NH$_3$molecule ratio. The SO$_2$removal efficiency was not significantly effected by applied voltage and slightly increased with increasing NH$_3$molecule ratio. It could be found that it is possible to use CH$_4$for NOx and SO$_2$removal by corona radical shower systems.

• Journal of Advanced Marine Engineering and Technology
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• 제23권6호
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• pp.755-760
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• 1999

To remove nitrogen oxides(NOx) in exhaust gas of diesel engine three-way catalytic process with plasma discharger has great possibilities. Characteristics of NOx removal depends on NO conver-sion to $NO_2$ and /or $HNO_3$ due to high activation energies for NO oxidation and reduction, NOx removal efficiency by using three-way catalytic with plasma discharger indicated about 50% at 40watt power consumption condition.

• 한국응용과학기술학회지
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• 제36권2호
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• pp.668-675
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• 2019

대기오염물질 중 미세먼지는 심각한 사회적 환경문제로 인식되고 있다. 미세먼지의 원인 물질 중 하나인 질소산화물(NOx)은 석탄화력발전소의 연소공정에서 주로 발생하므로 효율적인 NOx 제거가 필요한 실정이다. 본 연구에서는 선택적 촉매 환원법(Selective Catalytic Reduction, SCR)을 이용한 NOx 제거에서 $TiO_2$ 광촉매의 NO 제거효율을 연구하였다. NO 제거효율을 평가하기 위해 발열제가 내장된 $Al_2O_3$ 기판 표면에 $TiO_2$ 촉매와 인산염의 접착 바인더를 혼합하여 도포한 후 제조된 기판을 열처리하면서 실험을 수행하였다. 온도에 따른 촉매의 NO 제거효율을 평가하였고, 촉매의 물리화학적 특성을 위하여 XRD, SEM, TG-DTA, BET 분석을 수행하였다. NOx 제거 효율은 시간에 따른 온도변화($250^{\circ}C{\sim}500^{\circ}C$)로 20분에서 제거효율은 58.7%~65.9%이며, 30분에서 63.7%~66.0%로 나타났다. 질소산화물 제거용 SCR로 사용되는 $TiO_2$는 $300^{\circ}C$가 제거효율이 가장 효율적인 것으로 판단된다.

• 한국대기환경학회지
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• 제14권4호
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• pp.333-342
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• 1998

Plasma process has great possibilities to remove SOx, NOx simultaneously with high treatment efficiency and is expected to be suitable for small or middle plants. It was accomplished to evaluate SO2, NOx control possibility and achieve basic data to control pollutants by use of Surface Discharge Induced Plasma Chemical Process (SPCP) in this study. O3 generation characteristics by discharge of a plate was proportional to O2 concentration and power consumption and inversely proportional to temperature and humidity, In case of dry air, NOx was highly generated by N2 and O2 in air during the plasma discharge process but it was decreased considerably as H2O was added. SO2 removal efficiency was very high, and removal rate was 170,350 mEA at 30,50 watt respectively in flue gas which is usually contain HIO. NOx removal efficiency was about 57% at 40 watt power consumption with 7.5% humidity. It is estimated that H2O has an important role in reaction mechanism with pollutants according to plasma discharge.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.1087-1089
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• 1999

This paper presents the removal characteristics of nitrogen oxides (NOx) by the dielectric ($Al_{2}O_{3}$) packed-bed plasma reactor. Reactor packed with 5-mm diameter $Al_{2}O_{3}$ beads, and was designed to remove NOx at atmospheric pressures from the moving pollution source such as diesel automobile. The experiments were conducted for applied voltages from 5 to 10kV, flue gas rate from 2 to 5L/min, and frequency from 0.5 to 2kHz. The NOx removal efficiency significantly increased with increasing applied voltage. Especially removal rate significantly increased with increasing frequency. However, in this experiment discharge power was relatively high.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.406-409
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• 1999

Experimental Investigations were carried out to remove NOx, SOx simultaneously from simulated flue gas[NO(0.02%)-SO$_2$(0.08%)-$CO_2$-Air-$N_2$] by using a plasma chemical reaction. Ammonia gas(14.81%) balanced by argon was diluted by all and was Introduced to mall simulated flue gas duct through NH$_3$ Injection system which is in downstream of reactor. The NH$_3$ molecular ratio(MR) was determined based on (NH3) to [NO+S0$_2$]. MR is 1, 1.5, 2.5. The NOx removal rate significantly increased with increasing NaOH bubble quantity. The SO$_2$ removal rate was not significantly effected by applied voltage, however it fairly Increased with increasing NH$_3$ molecule ratio. By-product aerosol particle was observed by XRD(X-ray diffraction) after sampling, The NOx, SOx removal rates, when H2O vapour bubbled by dry all was injected to plasma reactor, were better than those of other cases. When aqueous NaOH solution(20%) bubbled by 2.5( ι /min) of $N_2$ and 0.5 ( ι /min) NH$_3$(MR=1.5) were injected to simulated flue gas, The NOx. SOx removal rate was 95 ~ 100[%]

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1794-1796
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• 1998

In this study, the $SO_2$ addition effect on NOx removal has been conducted from a combustion flue gases by the do corona discharge-activated radical shower systems. The simulated flue gases were consisted of NO-O_2-$N_2$, NO-$CO_2-N_2-O_2$ and $NO-SO_2-CO_2-Na-O_2$([NO]o:200ppm and $[SO_2]o$:800ppm). The injection gases used as radical source gases were $NH_3$-Ar-air. $SO_2$ and NOx removal efficiency and the other by-products were measured by Fourier Transform Infrared(FTIR) as well as $SO_2$. NOx and $NO_2$ gas detectors. By-product aerosol particles were also observed by Condensation Nucleation Particle Counter(CNPC) and SEM images after sampling. The results showed that asignificant aerosol Particle formation was observed during a removal operation in corona radical shower systems. The NOx removal efficiency significantly increased with increasing applied voltage and $NH_3$ molecule ratio. The $SO_2$ removal efficiency was not significantly effected by applied voltage and slightly increased with increasing $NH_3$ molecule ratio. The NOx removal efficiency for NO-$SO_2-CO_2-N_2-O_2$ was better than that for NO-$CO_2-N_2-O_2$.