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청정기술 = Clean technology, v.22 no.4, 2016년, pp.211 - 224
박순희 (고려대학교 초저에너지 초저배출 자동차 사업단) , 이관영 (고려대학교 화공생명공학과) , 조성준 (전남대학교 화학공학부)
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Three way catalyst has been used extensively for the exhaust gas treatment for the internal combustion gasoline engine. While, numerous research efforts have been directed to develop various technologies for the abatement of exhaust gas from diesel engine. Diesel engine operating under lean conditio...
| 핵심어 | 질문 | 논문에서 추출한 답변 |
|---|---|---|
| 디젤 엔진은 가솔린 엔진과 같이 삼원촉매를 이용하여 NOx를 제거하는 것이 어려운 이유는? | 삼원촉매를 이용하여 배기가스 내 CO, HC, NOx를 서로 산화-환원시켜 효과적으로 제거하는 가솔린 엔진과 달리 산소과잉 조건에서 운전하는 디젤 엔진은 NOx를 제거하기 어렵다[2]. 차세대 엔진의 구조 개선, 배기가스 재순환장치(exhaust gas recirculation, EGR)의 도입 등으로 디젤 엔진 배기가스의 온도가 낮아지고 NOx의 배출량 역시 크게 감소하였지만, 이런 방법으로는 더욱 엄격해진 환경 규제를 만족할 수준까지 낮추기가 어려워 배기가스 내 NOx를 제거하기 위해 촉매를 사용하는 후처리 기술이 활발히 연구되고 있다. | |
| 자동차에서 발생하는 유해한 배기가스 성분은 어떤 것이 있는가? | 자동차에서 발생하는 유해한 배기가스 성분은 일산화탄소(CO), 탄화수소(HC), 질소산화물(NOx) 등이 있다. 이 중에서 질소산화물은 자동차에서 배출되는 대표적인 유해물질로 산성비나 스모그 등과 같은 환경오염문제를 야기할 수 있는 주요 원인 중 하나로 알려져 있다. | |
| EGR의 한계점은? | EGR은 연소온도를 낮추어 질소산화물(NOx)의 발생량을 줄이기 때문에 연소실로 재순환되는 배기가스의 온도를 낮추어주기 위해 냉각기(EGR Cooler)를 장착하면 효과가 더욱 커진다[3]. 반면 입자상물질(particulate matter, PM) 발생량은 증가하고 혼합기의 착화성이 불량하게 되어 기관의 출력을 감소시키는 단점이 있다. |
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