• 공업화학
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• 제20권4호
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• pp.355-362
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• 2009

석유를 기반으로 한 연료는 가까운 미래에 고갈될 것이다. 디메틸에테르(Di-methyl Ether, DME)는 청정에너지이며 천연가스,석탄 및 바이오매스 등으로 생산이 가능하다.DME는 분자구조 내에 탄소-탄소 결합이 없는 함산소 연료로 연소시 그을음과 황산화물을 발생하지 않으며, 물리적 특성이 액화석유가스(Liquified Petroleum Gas, LPG)와 매우 유사하여 LPG 유통인프라를 그대로 활용할 수 있다. DME는 세탄값이 55~60 정도로 높아 디젤 자동차용 연료로도 활용이 가능하다.차세대 청정연료로 혹은 차세대 화학공업 원료물질로 전력생산,디젤 연료, 가정용 연료 및 연료전지 등에 사용이 가능하다.본 총설에서는DME의 특성, 표준화, 국내외의 기술개발현황, 대체연료로서의 활용에 대해 살펴보고자 한다.

• 한국자동차공학회논문집
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• 제18권5호
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• pp.76-84
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• 2010

The aim of this study is to analyze the effect of the ethanol blending in diesel-ethanol blended fuels on the spray and combustion characteristics in a common-rail four-cylinder diesel engine. For the analysis of the spray characteristics, the spray images were obtained using a high speed camera with metal-halide lamps. From these spray images, the macroscopic spray characteristics such as the spray tip penetration and spray cone angle were investigated. Also, the combustion characteristics including the combustion pressure and the rate of heat release were studied with the analysis of the exhaust emissions in diesel-ethanol blended fuel driven diesel engine. It can be confirmed from the experiment on spray characteristics of diesel-ethanol blended fuels that the increased ethanol blending ratio induced the decrease of the spray tip penetration after the end of the injection. The spray cone angle slightly increased by the blending of ethanol fuel. In the experiment on atomization characteristics, the ethanol blending caused the improvement of the diesel atomization performance. On the other hand, at the same engine load condition, the increase of the ethanol blending ratio lead to lengthen the ignition delays, and to decrease the peak combustion pressure and the rate of heat release. Totally, the combustion and emission characteristics of ULSD and DE10 showed similar characteristics. However, in the case of DE20, CO and HC rapidly increased, and $NO_x$ decreased. It can be believed that 20% ethanol disturbed the combustion of diesel-ethanol blended fuel due to the low cetane number and evaporation.

• 한국자동차공학회논문집
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• 제15권6호
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• pp.17-22
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• 2007

GTL(Gas-to-Liquids) fuel technology was converted from the natural gas, coal and biomass into the diesel or kerosene by Fisher-Tropsch synthesis. GTL fuel have very good merits on high cetane number, low density, free sulfur, lower aromatics contents and no poly-aromatic hydrocarbons as well as the autoignition characteristics. These physical properties make it valuable as a diesel fuel with lower emissions than the conventional diesel fuel. Furthermore, GTL fuel can be use not to the engine any modification. Therefore, to evaluate emissions of GTL fuel, the tested diesel vehicles were fueled on blends of GTL fuel/ultra low sulfur diesel fuel(ULSD). And then, we found out that GTL fuel reduced regulated emissions(CO, NOx, HC, PM) compare with conventional diesel fuel.

• 한국자동차공학회논문집
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• 제15권2호
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• pp.15-21
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• 2007

The aim of this paper is controlling ignition timing and load in homogeneous charge compression ignition (HCCI) combustion with low cetane number fuel, hydrogen. Homogeneous charge compression ignition (HCCI) combustion is an advanced combustion technology that achieves higher thermal efficiency and lower $NO_x$ emissions than that of conventional combustion system. Dimethyl ether (DME), which has been researched widely as the most attractive alternative fuel of diesel, is attractive for HCCI combustion because of the easy evaporation. In this study, the single cylinder DME engine operated with a direct injection system has been used to investigate combustion processes and emissions of DME HCCI with a premixed hydrogen supply. The experiment was carried out under various engine speed and fraction rates of hydrogen. As a result, the increase of fraction rates of hydrogen retard the DME ignition timing and eliminated the knocking during high engine speed condition. IMEP was increased with increase of fraction rates of hydrogen by 30%. 40% of the fraction rates of hydrogen resulted in misfiring. The $NO_x$ emission was reduced by increasing the fraction rates of hydrogen, but HC emission was increased.

• 한국자동차공학회논문집
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• 제22권4호
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• pp.1-9
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• 2014

The vast stores of biomass available in the worldwide have the potential to displace significant amounts of petroleum fuels. Fast pyrolysis of biomass is one of several paths by which we can convert biomass to higher value products. The wood pyrolysis oil (WPO) has been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of WPO in a diesel engine requires modifications due to low energy density, high water contents, high acidity, high viscosity, and low cetane number of the WPO. One possible method by which the shortcomings may be circumvented is to co-fire WPO with other petroleum fuels. WPO has poor miscibility with light petroleum fuel oils; the most suitable candidates fuels for direct fuel mixing are methanol or ethanol. Early mixing with methanol or ethanol has the added benefit of significantly improving the storage and handling properties of the WPO. For separate injection co-firing, a WPO-ethanol blended fuel can be fired through diesel pilot injection in a dual-injection dieel engine. In this study, the performance and emission characteristics of a dual-injection diesel engine fuelled with diesel (pilot injection) and WPO-ethanol blend (main injection) were experimentally investigated. Results showed that although stable engine operation was possible with separate injection co-firing, the fuel conversion efficiency was slightly decreased due to high water contents of WPO compare to diesel combustion.

• 에너지공학
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• 제16권3호
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• pp.120-127
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• 2007

본 연구의 목적은 디젤연소장의 분위기조건에 따라 다성분 혼합연료의 질량분률이 분무착화 및 연소특성에 미치는 영향을 실험적으로 고찰하는데 있다. 착화 및 연소특성은 화학발광계측법 및 직접촬영법을 이용하여 분석되었다. 실험은 광계측기를 사용하여 RCEM에서 이루어졌으며, 이소옥탄, 노말 도데칸, 노말 헥사데칸으로 혼합한 다성분연료는 커먼레일 인젝터의 전자제어에 의해 RCEM의 연소실 내로 분사된다. 실험조건은 분사압력 42, 72, 112 MPa과 분위기온도 700, 800, 900 K로 하였다. 그 결과로서 착화지연은 고세탄가성분에 의존하고, 분위기온도가 낮을 경우 저비점성분 혼합비율의 증가에 따라 휘도영역이 현저하게 낮아지며, 열발생률이 증가하면서 확산연소기간을 단축시킨다.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.178-185
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• 2007

A study is improvement of power and emission in a inline-pump Dr diesel engine by using Dimethyl ether Fuel. Dimethyl ether (DME) is an oxygenated fuel with a cetane number higher than that of diesel oil. It meets the ULEV emission regulation and reduces the smoke to almost zero when used in a diesel engine. But NOx emission is almost same and CO, THC emissions are lower than that of diesel engine. The emissions aren't satisfied the stronger emission regulation in the further. Generally DOC (Diesel Oxidation Catalyst) is used to reduce CO & THC emissions and EGR (Exhaust Gas Recirculation) system is used to reduce NOx emission. Test results showed that the torque and the power with DME were almost same as those of pure diesel oil, but the brake thermal efficiency increased a little. also the BSEC (Brake Specific Energy Consumption) with DME was similar that of diesel. The test results showed that the DOC was the vary effective method to reduce the CO emission in case of Dimethyl Ether Fuel in diesel engine. But, THC emission is showed a little reduction rates. Also EGR system was the very effective method to reduce the NOx emission in case of Dimethyl Ether Fuel in diesel engine.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.84-91
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• 2008

Due to increasing need for better emission characteristics and lower fuel consumption rate in automotive engines, alternative fuels are drawing more attentions recently. The GTL (gas to liquid) is the one of most favored candidates. In this study, emission characteristics are compared between diesel and GTL fuel in commercial 2.0 liter diesel engine and vehicle with CRDi(Common Rail Direct injection) system. The effects of injection timings on emission and fuel consumption rate are compared at various engine speeds and loads. Noticeable reduction in HC, CO and PM emissions are observed due to higher cetane number and low sulfur and aromatic contents in GTL. On the trade-off curve of NOx and PM(Particulate matter) GTL showed much more benefits than diesel, where about 30% of PM mass decreased at the same operating conditions. On CVS 75 mode test in vehicle, GTL showed an excellent emission enhancement, in which 50% of HC, 21% of PM, and 12% of NOx engine-out emissions are decreased compared to ULSD(Ultra low sulfur diesel) fuel.

• 에너지공학
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• 제24권4호
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• pp.33-41
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• 2015

DME는 높은 세탄가와 낮은 배출가스로 인하여 청정 디젤엔진 대체연료로 사용될 수 있고, LPG와 물리적 특성이 유사하기 때문에 혼합사용이 가능하다. 본 연구에서는 DME-LPG 혼합연료를 LPG 차량 연료에 적용한 실증평가를 수행하였다. 평가 차량으로는 LPG 연료 공급방식별로 액상연료공급방식(LPLi), 기상연료공급방식(LPGi), 분배식펌프 방식(Mixer type)의 LPG 자동차를 선택하였다. 배출가스(CO, THC, $NO_X$)와 연료소비효율에 대한 영향을 비교하기 위하여 LPG와 DME-LPG 혼합연료에 대한 성능평가를 수행하였다. 차량의 주행거리가 증가함에 따라 DME-LPG 혼합연료를 사용한 차량의 배출가스와 연료소비효율은 LPG 연료를 사용한 경우와 비교해서 동등한 수준으로 평가되었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.795-796
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• 2010

바이오매스로부터 합성액체오일을 생산하기 위한 방법의 하나로써 Fischer-Tropsch 합성이 세계적으로 주목을 받고 있다. $C_7-C_{15}$ 파라핀의 수첨이성화 반응은 세탄넘버의 향상과 저점도, 유동점, 및 어는점 등의 저온유동특성의 개선을 위하여 디젤연료의 생산 공정에 적용된다. Fischer-Tropsch 합성으로부터 생산되는 Jet fuel 등의 상업적인 제품들은 낮은 끓는점과 유동점을 개선해야 한다. 본 연구는 합성 오일로부터 bio-jet fuel을 제조하기 위한 수첨이성화 반응용 촉매를 개발하는데 있다. 수첨이성화 반응용 백금/제올라이트 촉매의 특성을 분석하고 모델반응으로써 도데칸의 수첨이성화반응 성능을 회분식반응기에서 조사하였다.