The diesel engine is excellent in economic and thermal efficiency, and is widely used as a power source for industries and automobiles. However, the problem of environmental pollution caused by exhaust gas has recently become serious and the development of alternative energy resources is urgently required due to depletion of fossil fuel. Because biodiesel is similar in properties to light oil, it is being used as fuel for diesel engines by replacing or mixing conventional light oil. As the blending of biodiesel fuel in diesel increases, the emission of harmful substances is decreased as compared with the general diesel fuel, and the supply is increasing. In this study, the effects of biodiesel fuel on engine power and exhaust gas were investigated, and empirical formulas for various NOx and Smoke exhaust gases were derived based on biodiesel blending fuel.

국가 온실가스 인벤토리를 Tier 2 이상의 수준으로 향상시키기 위해서는 IPCC 기본값 대신 국가 고유의 배출계수가 개발 및 이용되어야 한다. 국가 고유 배출계수는 에너지원 종류, 에너지 공정, 시간 추세에 따라 달라지기 때문에, 각 에너지원별 특성값을 파악하는 것은 정확한 인벤토리 구축에 중요한 부분을 차지한다. 국내 석유계 에너지원의 물성은 시간의 경과에 따라 큰 변화는 없었으며, 국내에서 고시되고 있는 에너지원별 열량환산기준 상의 석유계 에너지원에 대한 열량 및 탄소배출계수를 2013년과 2016년에 실제 시료를 수집하여 발열량, 탄소함량 및 탄소배출계수를 산정한 결과값과의 비교분석에서는 대체적으로 일정한 값을 유지하고 있는 것으로 나타났다. 또한, 석유계 에너지원별로 산출된 순발열량과 탄소배 출계수는 2006 IPCC Guideline에 나타낸 값들과 비교하였으며, 대부분의 에너지원이 2006 IPCC G/L의 기본값 및 상한, 하한 범위내의 값을 나타내었다.

대기오염에 대한 관심은 국내·외에서 점진적으로 상승하고 있으며, 자동차 및 연료 연구자들은 청정(친환경 대체연료) 연료와 연료품질 향상 등을 이용하여 새로운 엔진 설계, 혁신적인 후처리 시스템 등의 연구를 통하여 차량 배기가스 및 온실가스를 감소시키고자 노력하고 있다. 이에 본 연구에서는 각기 다른 차량기술이 적용된 휘발유, 경유, LPG를 연료로 사용하는 7대의 차량을 대상으로 국내·외에서 법적시험모드로 사용되고 있는 도심모드, 고속모드, 급가·감속, 에어컨사용 및 겨울철 특성을 반영한 저온모드에서 온실가스의 배출특성을 확인하고자 하였다. 사용연료에 관계없이 대부분의 온실가스는 저온인 Cold FTP-75 모드에서 가장 안 좋은 결과가 나타나는 경향을 가지고 있다. 각 차량별 온실가스 증가 요인으로는 가솔린 차량인 A차량(2.0 MPI)과 B차량(2.4 GDI)에서는 최고속 및 급가·감속 , 에어컨 사용 , 저온 조건의 순인데 비해 E차량(1.6 T-GDI)은 에어컨 사용, 최고속 및 급가·감속 , 저온 조건의 순이다. G차량 (LPLi)은 에어컨 사용 , 저온 , 최고속 및 급가·감속 조건의 순으로 가솔린 차량과 다른 특성을 가지고 있다. 경유 차량에 있어서는 A차량(2.0 w/o DPF)과 B차량(2.2 w/ DPF)은 최고속 및 급가·감속 , 에어컨 사용, 저온 조건의 순이었고, F차량(1.6 w/ DPF)은 저온, 에어컨 사용, 최고속 및 급가·감속 조건의 순으로 확인되었다. 따라서, 각 연료별로 배출가스 저감 기술을 다르게 적용하여야 효과적인 방법이라고 할 수 있겠다.

국내·외에서 대기오염에 대한 관심이 점점 증가함에 따라 자동차 및 연료관련 분야의 연구자들은 새로운 엔진설계, 향상된 후처리장치, 청정연료 그리고 연료품질향상을 통해 자동차의 배출가스 감소를 위하여 지속적으로 노력해 왔다. 따라서, 본 연구에서는 자동차의 증발가스와 성능, 환경성에 대해 살펴보고자 하였으며, 연료의 옥탄가 향상제로 쓰이는 바이오 에탄올, 바이오 부탄올, 바이오 ETBE (Ethyl Tertia ry Butyl Ether), MTBE (Methyl Tertiary Butyl Ether)가 환경에 미치는 문제점에 대해 살펴보고자 하였다. 주로 휘발유의 옥탄가 향상제로 쓰이는 바이오 에탄올, 바이오 부탄올, 바이오 ETBE, MTBE가 휘발유 연료 특성 중 증발가스에 미치는 영향에 대해 살펴보았으며, 바이오 연료 특성에 대한 가솔린 자동차의 가속 및 동력 성능을 살펴보았다. 실험결과 증발가스는 최대 1.04g/test로 모든 시험 연료가 국내 배출가스 기준에 부합함을 알 수 있었으며, 원료에 대한 증기압 측정 결과 바이오에탄올 15kPa, 바이오 부탄올 1.6k Pa로 E3급 연료 제조 시 바이오 부탄올 함유량을 늘리면 증기압과 증발가스 또한 낮게 나타났다. 또한, 바이오 연료의 종류에 따라 유사한 가속 및 동력 성능을 나타내었으며, 바이오 부탄올과 바이오 에탄올 비교 시 가속 성능이 약 3.9%, 출력은 0.8% 개선되었다.

Seasonal emission characteristics of odors and methane were investigated throughout the period of 17 months in which the emission status of odors and methane from soil cover layers in a sanitary landfill was measured. Complex odor emitted from soil cover layers fluctuated largely at the range of 7~20,800 OU (Odor Unit) in odor dilution ratio, and the median and average values were 2,080 and 4,203 OU, respectively. The intensity of complex odor showed higher values in the spring (5,663 ± 4,033 OU) and winter (6,056 ± 8,372 OU) than in the summer (1,698 ± 3,676 OU) and fall (1,761 ± 451 OU). Based on average concentrations, the compounds with high contribution values for the sum of the odor quotient (SOQ) were hydrogen sulfide (46.1%), methyl mercaptan (26.4%), and dimethyl sulfide (16.8%). This result shows that sulfur compounds were the main odor-causing compounds in the target landfill. The flux of complex odor was 0.17~70.36 OU·m−2·min−1 (Median 0.47, Average 5.40), and the flux of hydrogen sulfide was 0~114.70 μg·m−2·min−1 (Median 0.13, Average 5.91). The methane flux was 0.59~312.70 mg-CH4·m−2·min−1 (Median 25.61, Average 47.99). The methane concentrations emitted at the soil cover layers showed the highest values of 1.0~62.5% (Median 33.0, Average 21.1) in the spring, and the lowest values of 0.1~11.7% (Median 2.3, Average 3.7) in the winter. The methane concentrations in the summer and fall were similar with the average of 17.9% (range of 0.2-44.2%) and 12.5% (range of 2.2-42.5%), respectively. The emission data of odors and methane from soil cover layers can be utilized to establish management policy and apply mitigation technologies for the control of odor and greenhouse gases emitted in landfills.

It is very important to treat infected livestock carcasses safely and quickly. In this study, the degradation characteristics and odor generation characteristics of carcasses were investigated during the treatment of swine carcasses using the anaerobic burial composting method. While the carcasses were decomposed, the temperature remained high, at 40~55°C on average, and most of the carcasses were decomposed rapidly. The major odorcontributing substances in the buried composting method are sulfuric odor substances such as H2S, CH3SH, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), and the odor contribution of these substances is 93~99%. Among them, CH3SH, which accounts for about 56~89% of odor contribution, was the most representative indicator substance. Despite the anaerobic digestion process, the methane concentration in the digestion process was as low as 0.5~0.8% at the burial point of the carcass. The odor and methane produced during the decomposition of the carcasses decreased considerably during the discharge to the surface layer through the buried layer consisting of compost. These results suggest that anaerobic high temperature burial composting is one of the most useful methods to treat carcasses of infected livestock.

There has been growing concern over the emissions of formaldehyde and VOCs from automotive interior materials, as these could have an important impact on the in-vehicle air quality (IVAQ) of automotive vehicles. Odor along with VOCs refers to the automotive interior smell emitted directly or indirectly from any part of an automotive interior, based on human olfactory senses and a comfort evaluation of vehicle quality. The objective of this paper is to compare the odor intensity using GC/MS analysis method and odor sensory test in accordance with ISO 12219-2. For the compounds having low odor threshold value and high VOC concentration, it was found that there was the same tendency in each field of odor whether the instrument analysis method or the odor sensory test method was used.

In this study, swine and cattle farms located in Jeollanam-do were selected to analyze and evaluate the components of odorants in livestock facilities. In addition, a preliminary survey of the literature was conducted to establish a sampling and analysis method for phenol and indoles which are major components of odor emissions from livestock facilities, yet are not regulated by the laws. To establish a sampling and analysis method for phenol and indoles, Tedlar bag and Tenax-TA sorbent tube was used as background concentration of blank sample and samples according to the elapsed time. The results obtained indicate the GC/MS analysis with Tenax-TA sorbent tube sampling was an effective method for measuring the compounds of phenol and indoles. In the swine facility, the rankings of the odorants in order, from highest to lowest, were ammonia, sulfuric compounds, phenol/indoles, volatile fatty acids. The main odorants were hydrogen sulfide (41.3%) and 4-methylphenol (p-cresol, 13.9%). In the swine slurry storage, hydrogen sulfide (33.7%), ammonia (18.8%), and 3-methylindole (skatole, 15.7%) were the main odorants, and hydrogen sulfide (31%) and i-valeric acid (32.4%) were the main odorants in the cattle farms.

This study was conducted to investigate the effects of antiprotozoal plant extracts on in vitro ruminal fermentation and methane emission. Ruminal contents were collected from two ruminally-fistulated steers (Average BW: 450±30 kg) consuming 60% Timothy hay and 40% concentrate with free access to water and mineral block. Plant extracts, Lonicera japonica, Torreya nucifera, Zanthoxylum schinifolium, Poncirus trifoliate and Citrus junos, which have been known to have antiprotozoal and antiparasitic effects were added (5% of substrate) to the in vitro ruminal fermentation bottles containing the mixture of rumen fluid and McDougall’s buffer. The McDougall buffer (1000 ml) and ruminal inoculums (500 ml) were combined and 20 ml added to the 50 ml fermentation vessels containing 300 mg of substrate (DM basis). The fermentation vessels were placed in an incubator at 39°C for 3, 6, 9, 12, 24, 48 and 72 h with shaking. Plant extracts addition was decreased (p<0.05) acetate:propionate compared with control except with T. nucifera addition. Total gas production was increased (p<0.05), whereas methane emission was decreased (p<0.05) by all plant extracts compared with control at 12 h incubation. Methane emission at 24 h incubation was decreased for Lonicera japonica, Torreya nucifera, and Zanthoxylum schinifolium compared with control as well. In addition, methanogenic archaea was decreased (p<0.05) by all plant extracts at the 12 h incubation. These results indicate that the plant extracts may decrease methane emission by inhibiting methanogenesis without the decrease of total gas production in 12 h in vitro ruminal fermentation. Therefore, plant extracts which have the antiprotozoal effect may be promising feed additives for ruminants as a methane inhibitor

대기오염에 관한 관심은 국내·외에서 점진적으로 상승하고 있으며, 자동차와 연료분야 연구자 들은 청정 (친환경 대체연료) 연료와 연료품질 향상 등을 이용하여 새로운 엔진 설계, 혁신적인 후 처리 시스템 등의 많은 방법으로 차량 배기가스를 감소시키려고 노력하고 있다. 이러한 연구들은 주로 배출 가스 및 가솔린 차량의 PM 입자 배출 두 가지 이슈로 진행되고 있다. 자동차의 배출가스 및 미규제 물 질, PM (입자상 물질) 입자는 환경오염과 인체에 악영향을 주는 많은 문제를 일으키고 있다. 자동차 배 출가스의 주요 물질인 입자상 물질은 작은 입자로 구성된다. 이러한 작은 크기 때문에, 흡입된 입자는 쉽게 폐 깊숙이 침투 할 수 있다. 이 입자의 거친 표면들은 대기중에서 다른 독성 물질과 결합하기가 쉽다. 따라서 입자흡입의 위험을 증가시킨다. 함산소 연료첨가제 유형 (MTBE, 바이오 ETBE, 바이오 에 탄올, 바이오 부탄올)에 기초하여, 본 논문은 가솔린 자동차 배출가스 및 미규제 물질, 나노입자 배출에 산소함량의 영향을 토론하였다. 또한, 본 논문은 두 가지 시험모드를 사용하여 배출가스 특성을 평가하 였다. 시험모드는 FTP-75 및 HWFET 모드이었다.전체 측정항목에서 배출가스 규제 값보다 적게 배출되고 있는 것을 볼 수 있었고, 산소함량이 증가하 면서 측정항목에 따라 증감이 다름을 알 수 있었다.

대기오염에 관한 관심은 국내·외에서 점진적으로 상승하고 있으며, 자동차와 연료 연구자들은 청정(친환경 대체연료) 연료와 연료품질 향상 등을 이용하여 새로운 엔진 설계, 혁신적인 후 처리 시스 템 등의 많은 접근을 통하여 차량 유해 배기가스를 감소시키려고 노력하고 있다. 이러한 연구들은 가솔 린 자동차의 배출가스 및 가솔린 차량의 PM 입자 배출 등의 두 가지 이슈로 진행되고 있다. 자동차의 배출가스 및 PM(입자상 물질) 입자는 환경오염과 인체에 악영향을 주는 많은 문제를 일으키고 있다. 추 가로, 함산소 첨가제로서 연료에 포함된 MTBE (Methyl Tertiary Butyl Ether)에 대한 환경 문제점을 연 구하고 있다. 연구자들은 MTBE가 건강에 미치는 영향에 대한 많은 데이터를 가지고 있다. 이러한 데이 터는 높은 MTBE 용량에서 잠재적인 발암 물질 임을 결론짓고 있다. 함산소 연료첨가제 유형 (MTBE, 바이오 ETBE, 바이오 에탄올, 바이오 부탄올)에 기초하여, 본 논문 은 가솔린 연료 물성 및 증발가스 배출 특성에 대해 산소함량의 영향을 검토하였다. 또한, 연료물성에 대한 휘발유 차량의 가속 및 출력 성능을 평가하였다.

In this study, we investigated the effects of EGR rate and engine load on the emission characteristics in a 4-cylinder common rail direct injection diesel engine fueled with canola oil biodiesel (BD) blended fuel. The biodiesel blend fuel, BD20 (20 vol.% biodiesel and 80 vol.% ULSD blend) was used at an engine speed of 1,500rpm. The experimental results showed that with the increasing of EGR rate, the combustion pressure and rate of heat release (ROHR) of three test fuels were decreased, and the ignition delay was extended, the carbon monoxide (CO) and particulate matter (PM) emissions increased slightly, but the nitrogen oxide (NOx) emission decreased clearly. On the other hand, with the increasing of engine load, the combustion pressure and ROHR were increased, and the CO and PM emissions decreased. However, the NOx emission was increased due to the rise of the combustion temperature.

This study describes the effects of canola oil biodiesel (BD) blended fuel on the combustion performance and emission characteristics in a 4-cylinder common-rail direct injection diesel engine. In this study, with the increasing of engine loads, the biodiesel blend fuels(100 vol.% ULSD and 0 vol.% biodiesel blend, BD0; 80 vol.% ULSD and 20 vol.% biodiesel blend, BD20; 0 vol.% ULSD and 100 vol.% biodiesel blend, BD100; ULSD: ultra low sulfur diesel) were used at an engine speed of 1,500rpm. The experimental results showed that with the increasing of biodiesel blend rate, the combustion pressure decreased slightly at engine load of 20~60Nm. However, the rate of heat release (ROHR) increased clearly and ignition delay time was shortened. With the increasing of biodiesel blend rate, the carbon monoxide (CO) and particulate matter (PM) emissions were more decreased at all of the engine loads.

The objective of this study is to investigate the effect of operating conditions on the performance of small HSDI compression ignition engine. Combustion and exhaust emission characteristics of engine were studied by using CFD simulation with ECFM-3Z combustion model. The conditions of simulation were varied with injection timing, injection pressure, and operating speed, and the results were compared in terms of combustion pressure, rate of heat release, NOx and soot. It was found that as injection timing was advanced and injection pressure is increased, combustion pressure and rate of heat release were increased. As a result, NOx generation is increased. Soot generation is also increased due to the wall film caused by the increase of the injection pressure and locally the rich mixture caused by the effect of the advancing of injection timing.

This study was performed to investigate the effect of fuel combustion enhancing apparatus(FCEA) for ionization of intaking air into cylinder combustion chamber on the combustion performance and emissions characteristics in a 4-cylinder common-rail direct injection diesel engine. The experiments were applied to the engine at an engine speed of 1,500rpm under 20Nm, 40Nm, 60Nm and 80Nm conditions. The test results were compared to each other with or without the FCEA. In the case of the FCEA, the combustion pressure, peak combustion pressure and rate of heat release were increased slightly and the brake specific fuel consumption(BSFC) was decreased slightly when compared to that without the FCEA under all loads at an engine speed of 1,500rpm. However, in the case of the FCEA, the nitrogen oxide(NOx) were increased slightly, the carbon monoxide(CO) and particulate matter(PM) were decreased slightly when compared to that without the FCEA under all loads at an engine speed of 1,500rpm.