• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.664-670
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• 2012

A study on the in situ regeneration effect of commercial deactivated SCR catalyst which had been exposed to the off gas from the heavy oil fired power plant for a long time was carried out in a simulated in situ conditions by washing with distilled water and various acid solutions in a short time. The catalytic performance test of the regenerated SCR catalysts was carried out in the micro reactor with simulated off gas of the heavy oil fired power plant and all prepared catalysts were characterized by BET, Porosimeter, EDX (Energy Dispersive X-ray spectrometer) and ICP (Inductively Coupled Plasma) to investigate correlations between catalytic activity and surface characteristics of them. The characterization results of the regenerated catalysts showed that the specific surface area was restored 95% more than that of fresh catalyst. Under this study, the activity of the regenerated catalysts with acid solution (3~6 M) without using ultrasonic wave in a simulated in situ conditions was restored 90% more than that of the fresh catalyst. It was found that improved activity of regenerated catalyst was caused by removing the deactivating materials from the surface of the deactivated SCR catalyst through acid washing.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.201-208
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• 2010

The $SO_2$ and $NO_x$ removal with an activated coke catalyst was conducted by a two-stage reaction which first $SO_2$ was oxidized to $H_2SO_4$ and then $NO_x$ was reduced to $N_2$. But if unreacted sulfur dioxide entered in the second stage, the $NO_x$ reduction was hindered by the reaction with ammonia. In this study, experimental investigations by using lab-scale column apparatus on the product and the reactivity of $SO_2$ with ammonia over coke catalyst which was activated with sulfuric acid was carried out through ultimate analysis DTA, TGA and SEM of catalyst before and after the reaction. Also, the effect of reaction emperature on the reactivity of $SO_2$ with ammonia was determined by means of breakthrough curves with time. The obtained results from this study were summarized as following; Activated cokes were decreased carbon component and increased oxygen and sulfur components in comparison with original cokes. The products over coke catalyst were faced fine crystal of $(NH_4)_2SO_4$, which results in the pressure loss of reacting system. The order of general reactivity in terms of the reaction temperature after breakthrough for $SO_2$ was found to be $150^{\circ}C$ > $200^{\circ}C$ > $100^{\circ}C$. This was related to adsorption amounts of ammonia on the activated cokes.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.05a
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• pp.69-72
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• 1998

지속적인 경제성장과 산업발달과 더불어 에너지 소비량이 크게 증가하고 있고, 환경문제가 심각해지고 있다. 이에 따라 대기로 배출되는 질소산화물은 산성비 및 도심스모그의 주범이 되는 물질로서, 그 미치는 파장이 사회적으로 매우 크다. 이러한 질소산화물을 제거하는 방법으로서, 기존의 선택적 촉매 및 비촉매 환원법은 고온을 필요로 하므로, 설치 및 운전비가 많이 요구되는 방법들을 대체하기 위해 상온영역에서 조업되는 광촉매를 개발해서, 신기술을 확립하고, 환경규제에 대해 능동적으로 대처하여야 한다. 기존의 탈질공정에서는 부가적인 에너지가 필요하므로, 광촉매를 통한 질소산화물의 저감기술은 에너지 소비가 작다는 장점이 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.293-294
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• 2002

화석연료의 연소로부터 발생되는 질소산화물은 산성비, 광화학스모그 및 오존층 파괴에 관여하는 환경오염물질로서 대기오염의 주범이 되고 있다. 연소 후 배기가스 중의 질소산화물 제어를 위한 선택적 촉매환인공정(Selective Catalytic Reduction: SCR)은 안정적이며 고효율 설계가 가능하여 범용적으로 사용되고 있는 기술이다. SCR 공정은 최초 미국에서 개발되었으나 일본과 독일에서 발전시켜왔으며 국내에서도 공정의 핵심기술인 촉매에 대한 다양한 연구를 수행하여 일부에서는 상용화 수준에 이르고 있다. (중략)

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.496-498
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• 2011

본 논문에서는 알루미늄 드로스를 재활용하여 생성 된 수산화알루미늄을 이용하여 질소산화물 제거 SCR 촉매를 제조하였다. 현재 상용중인 촉매와 화학적 특성과 질소산화물 제거 효율을 비교하기 위해 동일 타입의 하니컴 형태의 $V_2O_5-WO_3-TiO_2-Al_2O_3$ SCR 촉매를 제조하였으며, XRF와 BET를 사용하여 화학적 특성을 평가 비교하였다. 또한 MR(Micro Reactor)을 이용하여 $350^{\circ}C$와 $450^{\circ}C$에서 질소산화물 제거 평가를 실시하였으며, 평가 결과 80~90%의 제거 효율을 확인하였다.

• 기계와재료
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• v.24 no.2
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• pp.62-71
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• 2012

세계적으로 NOx 저감 및 규제치의 강화로 인해 디젤기관에서 발생되는 NOx 제거에 대한 연구가 활발히 진행 중이며, 암모니아 환원제와 배출가스의 NOx를 혼합하여 촉매 존재하에서 NOx를 제거하는 시스템이 개발되고 있다. 대부분 암모니아를 보관성이 용의한 요소(Urea) 수용액으로 대체하여 배기관 내에 직접 요소수를 분사하며 요소 수용액이 고온의 배기가스에 의해 증발되어 암모니아를 환원시키며, 촉매를 통하여 탈질을 하는 Urea-SCR 시스템을 채택하고 있다. 따라서 촉매전단에서 요소수가 완전히 증발되고, 또한 촉매 입구에서 요소수의 증발로 인해 환원된 암모니아의 분포도 균일해야 함으로 Urea-SCR 시스템이 배기가스 유동 및 온도에 최적화된 분무특성을 가지는 분사제어 시스템을 제시하고자 한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.666-674
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• 2021

A selective catalyst reduction system (SCR) with an integrated bypass unit is proposed. Through simulations of the SCR, variations in flow to the catalyst due to the particular shape of the bypass shutting device in the SCR are also studied. The commercial software Ansys Fluent is used to develop the simulations. For the simulations, the catalyst of the SCR is modeled using the porous media method to reduce the calculation time and number of meshes, which is necessary because of the detailed modeling of the catalyst. Simulations are performed based on changes to the entrance angle to the catalyst and the size of the bypass shutting device. Finally, simulation results are used to compare and analyze the average velocity and uniformity of the flow to the catalyst.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1988.12a
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• pp.24-24
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• 1988

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.443-444
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.571-573
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• 2009