• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.8-13
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• 2008

Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.

• Particle and aerosol research
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• v.9 no.3
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• pp.149-161
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• 2013

Experiments on photochemical reactions of purified air alone in an indoor smog chamber were carried out after flushing Teflon bags with purified air for many hours in order to check the level of contamination on the chamber wall. Ozone concentrations were linearly increased from <4 ppb up to about 8 ppb with irradiation time for four hours. Outgassing of NOx from the chamber wall was found to be less than 1 ppb. New ultrafine particles were formed and grown up to about 70 nm during the photochemical reactions, and then total number and mass concentrations of particles were increased from <10 particles/$cm^3$ up to about 4,000 particles/$cm^3$ and $1.3{\mu}g/m^3$, respectively. The wall conditions of these Teflon bags flushed with purified air might not severly affect the chamber experimental results for photochemical reactions of polluted urban ambient air. The difference of gaseous species between two chambers was 2.4 ppb of ozone at most, indicating that the wall cleaning performance of two chambers was nearly similar.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.15-26
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• 2005

An experimental investigation of the gas-phase photooxidation of toluene-NO$_{x}$-air mixtures at sub-ppm concentrations has been carried out in a 6.9 m3, indoor smog chamber irradiated by blacklights. Measured parameters in the toluene-NO$_{x}$ experiments included $O_3$, NO, NO$_2$, NO$_{x}$, CO, SO$_2$ toluene, and air temperature. The initial toluene concentration ranged from 225 ppb to 991 ppb and the initial concentration ratio of toluene/NO$_{x}$ in ppbC/ppb was in the range of 5～20. It was found that the variation of gaseous species with irradiation time caused by the photooxidation of toluene-NO$_{x}$-air mixtures depended on the initial toluene concentration for similar concentration ratio of toluene/NO$_{x}$. The dependency of initial toluene concentration on the photooxidation of toluene-NO$_{x}$-air mixtures for toluene/NO$_{x}$=5～6 seemed to be opposite to that for toluene/NO$_{x}$=10～11. The arriving time at maximum ozone concentration depended on both initial toluene concentration and initial concentration ratio of toluene/NO$_{x}$. However, the maximum concentration of ozone formed by photooxidation depended only on the initial toluene concentration.luene concentration.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.27-38
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• 2005

An experimental investigation of the gas-phase photooxidation of toluene-NO$_{x}$-air mixtures at sub-ppm concentrations has been carried out in a 6.9 ㎥, indoor smog chamber irradiated by blacklights. Measured parameters in the toluene-NO$_{x}$ experiments included aerosol, $O_3$, NO, NO$_2$, NO$_{x}$ CO, SO$_2$ toluene, and air temperature. The initial toluene concentration ranged from 225 ppb to 991 ppb and the initial concentration ratio of toluene/NO$_{x}$ in ppbC/ppb was in the range of 5～20. It was found that the variation of aerosol number concentration with irradiation time caused by the photooxidation of toluene-NO$_{x}$-air mixtures depended on the initial toluene concentration for similar concentration ratio of toluene/NO$_{x}$. The dependency of initial toluene concentration on the photooxidation of toluene-NO$_{x}$-air mixtures for toluene/NO$_{x}$= 5～6 seemed to be opposite to that for toluene/NO$_{x}$=10～11. The maximum number concentration of aerosols formed by photooxidation and the aerosol yield depended on both initial toluene concentration and initial concentration ratio of toluene/NO$_{x}$. In this study, the aerosol yield, defined as aerosol formed per unit toluene consumed, was found to be 0.01～0.16.und to be 0.01～0.16.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.219-220
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• 2003

HONO의 대기 환경 적인 중요성은 오존과 HCHO의 광분해가 활발하지 않은 이른 아침시간에 OH라디칼의 생성원으로서 기여할 수 있기 때문이다. Smog chamber modeling 연구결과에 따르면 오존의 최고 농도와 오존의 형성 속도는 HONO의 광분해와 깊은 관련이 있으며 특히 오존 생성이 VOC-limited한 대기환경에서 특히 두드러진 효과가 있는 것으로 보고되었다. 대기 환경에서 HONO의 생성원으로 현재까지 연구결과 제시된 결과를 살펴보면, 3가지가 대표적으로 가)Homogeneous gas 반응 나)에어로졸 혹은 건물 및 지표면에서의 Heterogeneous 반응, 다)NOx 발생원으로부터의 직접적인 발생으로 조사되고 있으나 상대적인 기여도는 여전히 명확히 밝혀지고 있지 않다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.167-168
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• 2003

광화학 스모그는 대기 중으로 배출된 일차 오염물질인 /NO$_{x}$와 휘발성 유기화합물(volatile organic compounds)이 햇빛에 의해 반응하여 오존과 그외 다른 광화학 물질들을(photochemical oxidants) 생성시키는 현상이다. 서울의 경우 이런 VOCs 중에서 가장 많은 양을 차지하는 톨루엔은 광화학 반응을 통해 이차 유기 에어로졸(secondary organic aerosols)을 생성하는 능력이 매우 높은 방향족 화합물이다(Na and Kim, 2001). 지금까지 톨루엔의 이차 유기 에어로졸 생성에 관한 연구와 다른 방향족 탄화수소에 관한 연구가 스모그 챔버 실험을 통해 많이 이루어져 왔다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.43-44
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• 2003

스모그 챔버는 대기화학 반응을 물리적 변수를 제어할 수 있는 공간 내에서 재현하여 스모그 현상을 체계적으로 규명하기 위해 가장 많이 사용되는 방법이다(Dodge, 2000). 대기화학 반응을 통해 생성된 입자상 물질(secondary particles) 또는 초미세 입자(ultrafine particle, 〈0.1 $\mu\textrm{m}$)는 연속된 물리화학 반응을 통해 accumulation mode(0.1~l.0 $\mu\textrm{m}$) 입자로 성장한다. 특히, 대도시의 시정(visibility)은 accumulation mode 입자의 산란(scattering)과 흡수(adsorption)가 주요한 원인이기 때문에 이러한 물질의 생성에 영향을 주는 가스상 물질의 전화(gas-to-particle conversion) 반응과 초미세 입자의 성장 현상을 규명하는 것은 매우 중요하다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.377-378
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• 2003

휘발성유기화합물(volatile organic compounds, 이하 'VOCs')은 대기 중에서 태양광선에 의해 질소산화물과 광화학적 산화반응을 일으켜 그 결과 지표면의 오존농도를 증가시켜 스모그(Smog) 현상을 초래시키는 모든 유기화합물을 일컫는다. 이러한 VOCs를 제거하기 위하여 여러 방법이 제시되고 있는데, 촉매를 이용하여 VOCs를 산화시켜 제거하는 촉매 산화법은 촉매사용으로 인하여 소각법에 비하여 조업온도를 많이 떨어뜨릴 수 있으므로, 에너지 소비의 절감과 이에 따른 제2의 오염물질의 배출이 거의 없다는 점에서 유리한 면을 갖고 있어 VOCs 제거에 가장 적합한 방법이라고 할 수 있다. (중략)

• Journal of Environmental Science International
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• v.12 no.7
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• pp.825-833
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• 2003

The emission of volatile organic compounds (VOCs) generated from painting and coating processes is a worldwide problem as contributing factors to the development of photochemical smog and other environmental problems. Common methods of reducing VOC emissions are adsorption on activated carbon, membrane separation, absorption, incineration, or catalytic oxidation. In this article, the environmental issues caused by VOC emissions and the trend of legislation against such emissions will be surveyed first. Several conventional control technologies will then be summarized and the characteristics of each process will be introduced. Lastly, some examples will be described to show the hybrid processes which have been industrially applied for the recovery of VOC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1073-1075
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• 2001

The nitrogen oxides, NO and NO2, abbreviated usually as NOx, emitted from combustion facilities such as power plants and automobiles are the typical air-pollutants causing acid rain and photochemical smog. In order to solve the NOx-related pollution problems effectively, we need efficient techniques to monitor NOx in the combustion exhausts and in environments. Development of solid-state electrochemical devices for detecting NOx is demonstrated based on various combination of solid electrolytes and auxiliary sensing materials. The object of this research is to develop various sensor performance for solid state amperometric sensor, and to test gas sensor performance manufactured. So we try to present a guidance for developing amperometric gas sensor. We concentrated on development of manufacturing process and performance test.