NH₃-SCR 반응에서 스팀 처리된 zeolite BEA 촉매의 영향

박지혜(Ji Hye Park),조광희(Gwang Hee Cho),황라현(Ra Hyun Hwang),백정훈(Jeong Hun Baek),이광복(Kwang Bok Yi) 한국청정기술학회 2020 청정기술 Vol.26 No.2

아산화질소(N₂O)는 6대 온실가스 중 하나로 이산화탄소(CO₂)의 310배에 해당하는 지구온난화지수(global warming potential, GWP)를 나타내어 N₂O를 저감하는 것은 필수적이다. 선택적 촉매환원법(selective catalytic reduction, SCR)은 대기 오염 물질의 하나인 NOx의 제거를 위해 암모니아를 환원제로 사용하여 무해한 N₂ 및 H₂O로 전환하는 기술로 높은 탈질효율을 나타낸다. 본 연구에서는NH₃-SCR반응에서 스팀 처리된 Fe-BEA촉매가 활성에 미치는 영향을 조사하기 위하여 Fe-BEA 촉매는 Fe를 이온교환하기 전, 고정층 반응기로 100℃에서 2h 동안 스팀 처리 되었다. 제조된 촉매의 NH₃-SCR반응 테스트는 고정층 반응기로 WHSV = 180 h<SUP>-1</SUP>, 370 ~400℃에서 수행되었다. 100℃ 에서 스팀 처리된 Fe-BEA(100) 촉매가 370 ~ 390℃에서 Fe-BEA촉매보다 다소 높은 활성을 나타내었다. NH₃-SCR 활성에 영향을 주는 원인을 파악하기 위하여 제조된 촉매는 BET, ICP, NH₃-TPD, H₂-TPR, <SUP>27</SUP>Al MAS NMR을 통하여 특성분석 되었다. H₂-TPR결과를 통해 Fe-BEA(100) 촉매가 Fe-BEA 촉매 보다 isolated Fe<SUP>3+</SUP>의 환원이 더 많이 일어난 것을 확인하였으며, 스팀 처리는 활성종인 isolated Fe<SUP>3+</SUP>의 양을 늘려주어 활성이 증가한 것으로 판단된다. Nitrous oxide (N₂O) is one of the six greenhouse gases, and it is essential to reduce N₂O by showing a global warming potential (GWP) equivalent to 310 times that of carbon dioxide (CO₂). Selective catalytic reduction (SCR) is a technology that converts ammonia into harmless N₂ and H₂O by using ammonia as a reducing agent to remove NOx, one of the air pollutants; the process also produces high denitrification efficiency. In this study, the Fe-BEA catalyst was steam-treated at 100°C for 2h before Fe ion exchange in the fixed bed reactor in order to investigate the effect of the steam-treated Fe-BEA catalyst on the NH₃-SCR reaction. NH₃-SCR reaction test of synthesized catalysts was performed at WHSV = 180 h<SUP>-1</SUP>, 370 to 400°C in the fixed bed reactor. The Fe-BEA(100) catalyst steam-treated at 100 °C showed a somewhat higher activity than the Fe-BEA catalyst at 370 to 390 °C. The catalysts were characterized by BET, ICP, NH₃-TPD,H₂-TPR, and <SUP>27</SUP>Al MAS NMR in order to determine the cause affecting NH₃-SCR activity. The H₂-TPR result confirmed that the Fe-BEA(100) catalyst had a higher reduction of isolated Fe<SUP>3+</SUP> than the Fe-BEA catalyst, and that the steam treatment increased the amount of isolated Fe<SUP>3+</SUP> as an active species, thus increasing the activity.

북미 규제 대응을 위한 신품 디젤촉매의 NOx 과다배출 원인 분석

태지건(Jigeon Tae),박은경(Eunkyung Park),김성대(Sungdae Kim),유종표(Jongpyo Yoo),여권구(Gwonkoo Yeo) 한국자동차공학회 2016 한국자동차공학회 학술대회 및 전시회 Vol.2016 No.11

광양만권 산업체의 질소산화물 저감기술 적용성 연구

정경환 ( Kyong-hwan Chung ),고태석 ( Tae-suck Koh ),장덕례 ( Duck-rye Chang ),윤형선 ( Hyung-sun Yoon ),정승원 ( Seung-won Jeong ),정민철 ( Min-chul Chung ),안호근 ( Ho-geun Ahn ) 한국환경기술학회 2006 한국환경기술학회지 Vol.7 No.2

대기환경 규제지역으로 지정된 광양만권의 산업체에 대한 질소산화물 저감기술 적용성에 대해 조사하였다. 질소산화물 저감기술에 대한 효율성, 경제성 그리고 저감기술의 장단점을 비교하여 가장 효율적인 질소산화물 저감기술을 도출하고자 하였다. 광양만권 산업체가 적용하고 있는 질소산화물 저감기술은 질소산화물 배출량이 많을 경우 선택적 촉매환원법이나 선택적 무촉매환원법을 적용하는 비율이 높았다. 질소산화물 배출량이 100톤/년 이하인 공정에는 저NOx 버너를 사용하는 것이 경제적인 것으로 판단되었다. 광양만권 대기환경개선 실천계획을 달성하기 위해서는 질소산화물 발생량이 100톤/년 이상인 공정에는 선택적 촉매환원법을 적용하도록 유도하는 것이 바람직한 것으로 판단되었다. The application of reduction technology for nitrogen oxide was studied to the industries located in Gwangyang-bay area. The efficiency, strength and weakness, and economics for equipment and operation about the technology were investigated to establish the most efficient reduction technology on Gwangyang-bay area. The low NOx burner was useful to the industries emit low concentration of nitrogen oxide compound below 100 ton/year. It is certified that the selective catalytic reduction process has to be applied to the industries which emit a large amount of nitrogen oxide compound more than 100 ton/year to accomplish the action plan for improvement of air pollution on Gwangyang-bay area.

선박용 저속디젤엔진 적용을 위한 PM-NOx 동시저감 배출저감설비 해상실증 연구

고동균,정석영,김인섭,안계원,남연우 해양환경안전학회 2023 해양환경안전학회지 Vol.29 No.5

In this study, Selective catalytic reduction (SCR) + Diesel particulate filter (DPF) system was installed on a ship with a low-speed engine to conduct the on-board test. The target ship (2,881 gross tons, rated power 1,470 kW@240 rpm ×1) is a general cargo ship sailing in the coastal area. Drawing development, approvals and temporary survey of the ship were performed for the installation of the after-treatment system. For performance evaluation, the gaseous emission analyzer was used according to the NOx technical code and ISO-8178 method of measurement. The particulate matter analyzer used a smoke meter to measure black carbon, as discussed by the International Maritime Organization (IMO). Tests were conducted using MGO (0.043%) and LSFO (0.42%) fuels according to the sulfur content. The test conditions were selected by considering the engine rpm (130, 160 and 180). Gaseous emission and particulate matter (smoke) were measured according to the test conditions to confirm the reduction efficiency of the after treatment system. The results of NOx emission and particulate matter (smoke) revealed that reduction efficiency was more than 90%. The exhaust pressure met the allowable back pressure (less than 50 mbar). This study confirms the importance of the on-board test and the potential of SCR + DPF systems as a response technology for reducing nitrogen oxides and particulate matter. 본 연구에서는 소형선박용 중·고속 디젤엔진에 적용하여 연구 중인 SCR+DPF 기술을 저속엔진이 설치된 선박에 탑재하여 해상실증 시험을 수행하였다. 대상 선박(총 톤수 2,881 톤, 정격출력 1,470kW@240rpm ×1)은 국내 연해를 운항하는 일반화물선으로 배출저감설비의 선박 탑재를 위해 도면 개발, 승인 및 선박 임시검사를 수행하였다. 저감성능 확인을 위해서 가스상물질 측정장비는 NOx technical code 및 ISO-8178의 분석방법을 준용하는 장비를 사용하였으며, 입자상물질 측정장비는 국제해사기구(IMO)에서 논의하고 있는 블랙카본 측정 방법 중 하나인 스모크미터를 사용하였다. 시험은 황 함유량 따라 MGO(0.043%), LSFO(0.42%) 2종의 연료를 사용하였으며 실제 운항하는 엔진회전수(130, 160 및 180 rpm)를 고려하여 시험 조건을 설정하였다. 시험 조건에 따라 배출저감설비의 전·후단에서 가스상 및 입자상(매연) 물질을 측정하여 배출저감설비의 저감효율을 확인하였으며 모든 시험 조건에서 NOx의 경우 90% 이상, 입자상물질(매연)의 경우 95% 이상의 저감효율을 확인하였고 엔진 성능의 영향을 줄 수 있는 배기가스 압력은 허용배압 기준인 50mbar 이하를 만족하였다. 본 연구를 통해 해상실증 연구의 중요성과 중소형 저속엔진 선박의 질소산화물 및 입자상물질의 동시 저감을 위한 대응 기술로 SCR+DPF 설비 적용 가능성을 확인할 수 있었다.

NO_X 및 NH₃ Slip 저감을 위한 Urea-SCR 제어기반 모델 개발 및 검증

이승근,이성욱,강연식,Lee, Seung Geun,Lee, Seang Wock,Kang, Yeonsik 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.1

디젤 자동차의 점점 강화되는 $NO_X$ 배기가스 규제를 만족하기 위해서는 화학공학 기반의 SCR 반응모델을 사용한 모델기반 제어 알고리즘 개발이 필요하다. 본 연구에서는 소형 경유차량을 대상으로 $NO_X$ 를 저감하기 위한 배기 후처리 시스템 모델을 설계하기 위하여 SCR 시스템 모델링과 Rig 실험 및 Matlab 을 이용하여 시뮬레이션 및 검증을 하였다. SCR Rig 실험은 디젤엔진에서 배출되는 배기가스와 같은 성분의 모사가스를 생성하여 공간속도와 온도의 변화에 의한 SCR 의 $NO_X$ 저감효율에 대한 실험 조건 및 데이터를 획득하였다. 또한, 제안된 모델은 Rig 실험에서 사용한 실험조건과 결과데이터를 이용하여 Matlab 을 통해 검증하였으며 시뮬레이션 시 필요한 모델의 파라미터 값들은 실험데이터를 기반으로 최적화하였다. To satisfy stricter $NO_X$ emission regulations for light- and heavy-duty diesel vehicles, a control algorithm needs to be developed based on a selective catalytic reaction (SCR) dynamics model for chemical reactions. This paper presents the development and validation of a SCR dynamics model through test rig experiments and MATLAB simulations. A nonlinear state space model is proposed based on the mass conservation law of chemical reactions in the SCR dynamics model. Experiments were performed on a test rig to evaluate the effects of the $NO_X$ and $NH_3$ concentrations, gas temperature, and space velocity on the $NO_X$ conversion efficiency for the urea-SCR system. The parameter values of the proposed SCR model were identified using the experimental datasets. Finally, a control-oriented model for an SCR system was developed and validated from the experimental data in a MATLAB simulation. The results of this study should contribute toward developing a closed-loop control strategy for $NO_X$ and $NH_3$ slip reduction in the urea-SCR system for an actual engine test bench.

EURO-VI 규제 대응 배출가스 저감 장치에 대한 연구

박승원(Seung-won-Park),백두성(Doo-Sung-Baik) 인문사회과학기술융합학회 2018 예술인문사회융합멀티미디어논문지 Vol.8 No.11

과거 자동차는 성능위주로 개발되어 왔으며 지속적으로 증가하고 있으나 자동차에서 배출되는 배출가스는 총체적으로 환경오염에 미치는 영향이 매우 크다. 그러나 탄화수소 연료를 탈피하지 않고는 배출가스 저감을 이루기에는 어렵다. EURO-VI 규제는 질소산화물 저감을 위한 규제로 저감하기 위해서 다양한 기술이 개발되고 있다. 대표되는 기술이 LNT와 SCR이 있는데 SCR 경우는 환원제로 요소수를 분사시키는데 화학반응 과정에서 반응하지 못한 요소수는 대기로 노출되어 미세먼지 (PM)을 악화시킬 수 있다. 따라서 요소수의 분무상태, 기화상태 등을 예측하여 요소수 분사시스템의 최적화된 설계가 필요하다. 본 연구는 Euro-VI 배기규제 에 대응하기 위한 실험으로 질소산화물을 저감하기 위해서 요소수를 공급하는 시스템에 대한 연구로 SCR 적용에 따른 질소산화물의 저감 효과와 온도변화를 시간별로 측정하여 질소산화물의 저감 특성을 파악하고자 했다. 실험방법으로는 환원제인 요소수의 분사전략으로 Feedforward 방식을 적용하여 실험을 진행했으며 질소산화물 대비 요소수를 1:1로 분사하였다. In the past, cars were developed mainly for performance and the number have been increased but emissions have a large overall environmental impact and it is difficult to achieve emission reduction without leaving the hydrocarbon fuel. Various technologies are being developed to meet EURO-VI emission regulations to reduce nitrogen oxides. Typical technologies are LNT and SCR, and specially in SCR, the number of elements which did not respond in the chemical reaction was exposed to the atmosphere and may worsen the fine dust (PM). Therefore, optimal design of urea injection systems is needed by predicting the spray state, evaporation state, etc. This study aims to research urea injection system to reduce nitrogen oxides. It was intended to determine the reduction characteristics of nitrogen oxides by measuring their reduction effect and temperature time by time by applying the SCR in order to meet Euro-VI emission regulation. The experiment was conducted by applying feedforward method as urea injection strategy and the urea was sprayed at a ratio of 1: 1 relative to the nitrogen oxide.

질소산화물 저감을 위한 SCR TYPE CEM의 설계평가

정석윤(Seokyoon Jeong),정홍석(Hongseok Jung),이근우(Kunwoo Yi),조연근(Yonguen Cho),김경훈(Kyunghun Kim),김혜삼(Hyesam Kim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

SCR system for diesel engine vehicles is a device to reduce NOx from the emission gas of the diesel engine causing selective catalytic reaction by utilizing a metal catalyst with ammonia, NH₃, or HC as a reductant, and the device is recognized as a unique technology to meet future emission regulation for NOx such as Euro-V (2008). Under the current circumstance that the development for diverse post process technologies is in process, in this study, we evaluated the pressure and uniformity inside of SCR TYPE CEM(Catalyst Exhaust Muffler) reducing NOx among noxious gasses, through design and CFD(Computational Fluid Dynamics) analysis.

SCR 촉매 전단에서의 NH₃ 유동균일지수에 따른 NOx 저감률에 관한 수치적 연구

송미지(Miji Song),강석호(Seokho Kang),이성욱(Seangwock Lee),강연식(Yeonsik Kang),조용석(Yongseok Cho) 한국자동차공학회 2013 한국자동차공학회 부문종합 학술대회 Vol.2013 No.5

The application of SCR systems has been considered an effective exhaust after-treatment method for NOx emission control. Current Urea-SCR systems is possible to achieve 90% NOx if the NH3:NOx ratio is 1:1. However, the reaction has a limited non-uniformity of the exhaust gas flow and ammonia concentration distribution. A uniformity index is developed to evaluate the mixture quality in front of the SCR catalyst, which could also serve as an indirect indication of the de-NOx efficiency of the SCR system. Current papers have been presented the geometrical effects on flow mixing by using 3D Computational Fluid Dynamics (CFD) tool. In this paper, it is presented that the NOx reduction rate has been influenced by the flow uniformity index of NH3 in front of the catalytic converter by using 3D Computational Fluid Dynamics(CFD) tool. In order to achieve uniform flow at monolith front face, we have been changed with a various diffuser angle and mixer blade angle. It is found that the smaller diffuser angle and mixer blade angle are better NH3 uniformity in front of the SCR catalyst.

NH₃-SCR 촉매를 이용한 디젤기관에서의 NOx 저감에 관한 연구

박경균(Kyounggyun Park),이원석(Wonseok Lee),이성욱(Seongwock Lee),강호인(Hoin Kang),나완용(Wanyong Rha),손용기(Yonggy Son),임인혁(Inhyuk Im),황재원(Jaewon Hwang) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Diesel engines provide merits in the aspect of higher thermal efficiency and less CO₂ emission, but more problems on PM and NOx emissions. Selective Catalyst Reduction(SCR) technology is well-known to be effective for the reduction of NOx emission. SCR system can be classified into three kinds of NSR, NH₃-SCR and HC-SCR depending on reducing agents in jet spray. Because of poisoning problem of sulfur and unstable gas condition, much stable Urea-SCR system has been preferred to use instead. However, this research used to NH₃ gas instead Urea solution to model gas test. It is general to use NH₃-SCR catalyst for the NOx reduction on a diesel engine. This research focuses on the effects of gas temperature, SV(space velocity) and AR(aspect ratio) of NOx reduction rate. In this experiment was used the model gas which is similar to a diesel exhaust gas. NOx conversion rate is higher than 90% at the temperature of near 400℃ for all cases. As SV is lower, NOx conversion rate is decreased. On the contrary, as AR is higher, NOx conversion rate is increased.

선박용 질소산화물저감장치(SCR)의 국제경쟁력에 관한 연구

김성국(Sung Kuk Kim),양형선(Hyung Seon Yang) 한국해양비즈니스학회 2018 해양비즈니스 Vol.- No.40

In order to reduce Air pollutants by vessel, IMO and international organization are urging shipping companies to install new equipment as Nitrogen oxides(NOx) reduction equipment on ships. Since the abatement rule of new air pollutant gas requires the installation of Selective catalytic reduction(SCR) equipment, it is important to secure the export competitiveness of the products of the countries and companies producing them. Especially, in the case of Korea, which has a world-class shipbuilding industry, securing the competitiveness of SCR as a shipbuilding will contribute to strengthening competitiveness of the shipbuilding industry. Using the trade statistics, we grasped the international competitiveness of SCR in Germany, USA, Japan, China and Korea. As a result of analysis based on Trade specialization index and Intra-industry trade index, Korea has confirmed that Intra-industry trade is strong even though SCR corresponding to individual items and parts are in competition.