• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.67-70
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• 2007

Diesel autothermal reforming has several problems such as carbon deposition in reforming reactor, sulfur poisoning of catalyst, difficulty of aromatics decomposition and mixing problems of reactants(diesel, steam, oxygen). Severe carbon deposition causes the rapid performance degradation of reformer. Carbon deposition is formed from ethylene, carbon precursor. Ethylene was generated at the homogeneous reaction zone of the reactor entrance. This phenomenon is closely linked to the mixing of reactants. In this investigation, we try to minimize the ethylene generation at the reactor entrance atomization technique.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.773-776
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• 2009

In this paper, new concept of the diesel fuel processing is introduced for the stable operation of solid oxide fuel cells (SOFCs). Heavier hydrocarbons than $CH_4$, such as ethylene, ethane, propane, and etc., induce the carbon deposition on anode of SOFCs. In the reformate of heavy hydrocarbons (diesel, gasoline, kerosene, and JP-8), concentration of ethylene is usually higher than low hydrocarbons such as ethane, propane, and butane. So, removal of low hydrocarbons (over C1-hydrocarbons), especially ethylene, at the reformate gases is important for stable operation of SOFCs. New methodology as named "post-reformer" is introduced for removing the low hydrocarbons at the reformate gas stream. Catalyst of the NECS-PR4 is selected for post-reforming catalyst because the catalyst of NECS-PR4 shows the high selectivity for removing low hydrocarbons and achieving the high reforming efficiency. The diesel reformer and post-reformer are continuously operated for about 200 hours as integrated mode. The reforming performance is not degraded and low hydrocarbons in the diesel reformate are completely removed.

• Journal of Energy Engineering
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• v.13 no.4
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• pp.235-241
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• 2004

This experiment was undertaken to investigate the atomization characteristics of the high viscosity biodiesel blended fuel and ultrasonic energy irradiation one. Test fuels were conventional diesel fuel and biodiesel one. We compared to the characteristics of viscosity and surface tension, SMD between high viscosity biodiesel blended fuel and ultrasonic energy irradiation one. Sauter mean diameter was measured under the variation of the spray distance. Viscosity and surface tension were measured under the variation of the time trace. To measure the droplet size, we used the Malvern system 2600c. Droplet size distribution was analyzed from the result data of Malvern system. Through this experiment, we found that the condition of the ultrasonic energy irradiation situation had smaller Sauter mean diameter of droplet, viscosity and surface tension than those of the conventional situation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.7
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• pp.689-696
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• 2010

The Because of its high thermal efficiency, the direct injection (DI) diesel engine has emerged as a promising potential candidate in the field of transportation. However, the amount of nitrogen oxides ($NO_x$) increases in the local high-temperature regions and that of particulate matter (PM) increases in the diffusion flame region during diesel combustion. In the de-$NO_x$ system the Lean $NO_x$ Trap (LNT) catalyst is used, which absorbs $NO_x$ under lean exhaust gas conditions and releases it in rich conditions. This technology can provide a high $NO_x$-conversion efficiency, but the right amount of reducing agent should be supplied to the catalytic converter at the right time. In this research, the emission characteristics of a diesel engine equipped with a micro-reformer that acts as a reductants-supplying equipment were investigated using an LNT system, and the effects of the exhaust-gas temperature were also studied.

• Journal of Hydrogen and New Energy
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• v.12 no.4
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• pp.293-305
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• 2001

최근 디젤 대체 연료 및 발전용 연료로서 그 가능성을 인정받고 있는 DME(dimethyl ether, $CH_{3}OCH_{3}$)를 이용하여 수소를 생산하는 방법으로 DME 수증기 개질반응의 기초 실험을 수행하였다. DME 개질 반응의 생성물의 평형 조성 분포를 온도, 압력, 원료의 공급비$(H_{2}O/DME)$를 변수로 하여 열역학적으로 해석하였고, DME, 에탄올, 또는 메탄올 수증기 개질 반응의 생성물의 분포를 비교하여 수소 생산을 위한 공급원료로의 가능성을 검토하였다. 여러 종류의 개질 촉매를 사용하여 DME 개질 반응을 수행해 본 결과, 반응온도 $300^{\circ}C$, 반응압력 1atm, 원료 공급비$(H_{2}O/DME)=3$인 반응조건에서 1.0wt% $Pd/{\gamma}$-alumina가 가장 좋은 활성 및 60% 이상의 수소 선택도를 보여주었으, 또한 원료의 공급비가 증가함에 따라 DME의 전환율 및 주 생성물인 수소의 수율이 현저하게 증가함을 보여주었다.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.109-114
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• 2006

The reformed bio-diesel fuel irradiated by the ultrasonic wave is applied to the diesel engine of common rail in common use recently. This study has the object to examine the properties of engine performance and discharged materials. The bio-diesel fuel is mixed and used with the diesel fuel in common use at the ratio of $20\%\;or\; 100\%$. The ultrasonic energy is irradiated to the individually mixed fuel in order to reform the fuel. This fuel is applied to the engine in this experiment. And It is compared and analyzed from the experimental results with two cases irradiating the ultrasonic wave and no irradiating.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.15.2-15.2
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• 2005

• Journal of ILASS-Korea
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• v.12 no.3
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• pp.131-137
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• 2007

This is an experimental study on characteristics of engine performance and discharged materials in common-rail type diesel engine. The bio-diesel fuel is mixed with the diesel fuel in common use at the ratio of 20% or 100%. The diesel fuel and blended fuel is irradiated by ultrasonic wave energy. The diese1 fuel, blended fuel, reformed diesel fuel and reformed blended fuel by ultrasonic wave energy are applied to the experimental engine individually. The results are compared with one of the diesel fuel in common use and analyzed.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.115.2-115.2
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• 2010

Autothermal reforming(ATR) processes of hydrocarbon liquids such as diesel fuels are spotlighted as methods to produce hydrogen for Fuel cell. However, the use of heavy hydrocarbons as feedstocks for hydrogen production causes some problems which increase the catalyst deactivation by the carbon deposition. Coking can be inhibited by increasing the water dissociation on the catalyst surface. This results in catastrophic failure of whole system. Performance degradation of diesel autothermal reforming leads to increase of undesirable hydrocarbons at reformed gases and subsequently decrease the performance. In this study, perovskite-based catalysts were investigated as alternatives to substitute the noble metal catalyst for the ATR of diesel. The investigated perovskite structure was based on LaCrO3. and metals were added at the A-site to enhance oxygen ion mobility, transition metals were doped on the B-site to enhance the reformation. Substituted Lanthanum chromium perovskite were made by aqueous combustion synthesis, which can produce high surface area. And for the homogeneous fuel supply, we made ultrasonic injection system for reforming. We compared durability of evaporation system and ultrasonic system for fuel injection.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.78.1-78.1
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• 2010

The metal-supported solid oxide fuel cell (SOFC) was studied. Hydrocarbon fueled operation is necessary to make SOFC system. Different operating characteristics for metal-supported SOFC are used than for conventional ones as hydrocarbon fueled operation. Metal-supported SOFC was successfully fabricated by a high temperature sinter-joining method and the cathode was in-situ sintered. Synthetic gas, which is compounded as the diesel reformate gas composition and low hydrocarbons was completely removed by the diesel reformer. Metal-supported SOFC with synthetic gas was operated and evaluated and its characteristics analyzed. Button cell and $5{\times}5cm^2$ single stack were mainly operated and analyzed. Long-term operation using diesel reformate shows degradation, and degradation analysis was completed in the view of metal oxidation. Solution to increase stability of long-term operation was tried in the way of materials and operating conditions. Finally, $5{\times}5cm^2$ metal-supported single stack using synthetic gas was operated for 1000 hours under the modified condition.