• New & Renewable Energy
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• v.9 no.4
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• pp.40-50
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• 2013

This study was performed to investigate the potential of torrefied tulip tree (TT) for the production of pellets. For this purpose, chemical composition and fuel characteristics of torrefied TT were examined. In addition, pellets were fabricated by using sawdust of torrefied TT chip, and durability of the pellet was measured. Lignin content of torrefied TT was higher than that of non-torrefied TT, and increased with the increases of torrefaction temperature and time. Fuel characteristics of torrefied TT were affected by torrefied conditions, and the characteristics were influenced more by torrefaction temperature than by torrefaction time. Higher heating value (HHV) and ash content (AC) of torrefied tulip tree increased with increasing torrefaction temperature, and the values were much higher than HHV and AC values of non-torrefied TT. Durability of pellets fabricated with $230^{\circ}C$- and $250^{\circ}C$-torrefied TT was higher than that of $270^{\circ}C$-torrefied TT, and the value exceeded the minimum requirement (-97.50%) of the 1st-grade pellet standard designated by Korea Forest Research Institute. Based on the results, torrefaction treatment of $250^{\circ}C/50min$ to TT might be a optimal condition for the production of TT pellets considering the mass balance and fuel characteristics of TT as well as the durability of the pellets. Thus, it is confirmed that torrefied TT can be used as a raw material for the production of bio-pellets.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.160-160
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• 2010

• Journal of ILASS-Korea
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• v.13 no.1
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• pp.51-57
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• 2008

The objective of this study was to investigate the spray characteristics of commercial biodiesel fuel at various fuel injection conditions. To examine the effect of various factors on the development of a biodiesel sprays, experiments were conducted at the various injection pressures, ambient pressures and blending ratio of bio-diesel fuels. As a result of experimental study, it was shown that the increase of blending ratio of biodiesel had little influence on spray behaviors under applied fuel injection condition in this study. Because macroscopic characteristics of biodiesel-blended diesel fuel were almost same as that of petrodiesel fuels, it was found that the commercial biodisel is applicable to conventional diesel engine.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.567-577
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• 2019

Due to the depletion of fossil fuels and environmental pollution, demand for alternative energy is gradually increasing. Among the various methods, a method to convert biomass into alternative fuel has been proposed. The bio-fuel obtained from biomass through pyrolysis process is called pyrolysis oil (PO) or bio-oil. Because PO is difficult to use directly in conventional engines due to its poor fuel properties, various methods have been proposed to upgrade pyrolysis-oil. The simplest approach is to mix it with conventional fossil fuels. However, due to their different polarity of PO and fossil fuel, direct mixing is impossible. To resolve this problem, emulsification of two fuels with a proper surfactant was proposed, but it costs additional time and cost. Alternatively, the use of alcohol fuels as an organic solvent significantly improve the fuel properties such as fuel stability, calorific value and viscosity. In this study, blends of diesel, n-butanol, and coffee ground pyrolysis oil (CGPO) which is one of the promising PO, was applied to diesel generator. Combustion and emissions characteristics of blended fuels were investigated under the entire load range. Experimental results show that ignition delay is similar to that of diesel at high load. Although, hydrocarbon and carbon monoxide emissions are comparable to diesel, significant reduction of nitrogen oxides and particulate matter emissions were observed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.1
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• pp.39-44
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• 2013

The amount of greenhouse gas (GHG) emissions has been increasing steadily over the last 4 years, averaging 6.8 percent a year, due to the growth of low cost carriers and the increased demand for air transportations. For the aviation GHG reduction, various fuel saving activities are implemented in many areas such as high-efficiency aircraft and bio-fuel development in the technical part and low carbon flight procedures, short cut route development in the operational approach. Among the various reduction technologies, we focused on low carbon flight procedures that are crucial to GHG reduciton and suggested a reduction effect according to target implementation rate using by fuel saving estimation data in each aircraft type.

• Journal of ILASS-Korea
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• v.16 no.4
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• pp.210-214
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• 2011

This paper presents the spray characteristics of the gun type burner nozzle with bio-diesel blending rate. The burner nozzle used in this experiment is a pressure swirl type nozzle. For the spray characteristics, visualization of spray was conducted to obtain the spray angle, and laser diffraction spectroscope (LDS) was used for the measurement of the droplet diameters. The results showed that the $D_{max}$, SMD and spray angle were decreased with increasing the bio-diesel blending rate and BD30 (30% bio-diesel blending rate) could be found to be the maximum blending rate for using without any modification of the gun type burner of the homesize kerosene fuel boiler.

• Journal of Power System Engineering
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• v.8 no.2
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• pp.18-23
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• 2004

Recently many researchers have been studying the development of alternative energy due to serious environmental pollution and drying up fossil energy. Among various alternative fuels, authors investigated the physical and combustion characteristics of the bio diesel fuel(BDF) which was made from the wasted vegetable oil. In this study, PXI and LabVIEW, which is a novel measuring instrument and online analysis, was used to investigate the combustion characteristics of BDF in a DI diesel engine.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.579-584
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• 2007

대두유로부터 생산된 바이오디젤과 바이오디젤 혼합 연료유를 대상으로 지방산메틸에스터 함량과 화학적 분석을 통해 산화 특성과 오일의 수명 예측 연구를 수행하였다. 바이오디젤, 경유, BD5, BD20은 산화가 진행될수록 산가(Acid number), 동점도(Kinematic Viscosity) 및 밀도(Density)는 증가하였다. 산가 측정결과의 활용에 의해 임의의 온도조건에서 정확한 사용수명을 예측하기 위하여 화학속도론에 의거하여 각각의 연료에 대한 사용수명식을 도출하였다. 도출된 사용수명식으로부터 바이오디젤이 가장 빠르게 산화가 진행되었고 바이오디젤 혼합량이 증가할수록 사용수명이 단축되는 것을 확인할 수 있었다.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.2
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• pp.23-27
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• 2008

As a biofuel source, direct photosynthetic/metabolic biofuel cells (DPBFC) use cyanobacteria whose photosynthesis and metabolization reactions can convert light energy to electricity, In our previous work, we fabricated a prototype micro-DPBFC that could generate a peak current density of $36{\mu}A/cm^{2}$ and a maximum power density of $270nW/cm^{2}$. In this study, we improve on the previous results by using carbon micro electromechanical systems (C-MEMS), formed from the pyrolysis of patterned photoresist, to fabricate carbon electrodes of an arbitrary shape and controlled porosity to increase the surface area. With these new C-MEMS electrodes, the maximum power density of the micro-DPBFC was $516nW/cm^{2}$, a performance twice as good as the results of our previous work.

• New & Renewable Energy
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• v.3 no.2 s.10
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• pp.17-23
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• 2007

대두유로부터 생산된 바이오디젤과 바이오디젤 혼합 연료유를 대상으로 지방산메틸에스터 함량과 화학적 분석을 통해 산화 특성과 오일의 수명 예측 연구를 수행하였다. 바이오디젤, 경유, BD5, BD20은 산화가 진행될수록 산가(Acid number), 동점도(Kinematic Viscosity) 및 밀도(Density)는 증가하였다. 산가 측정결과의 활용에 의해 임의의 온도조건에서 정확한 사용수명을 예측하기 위하여 화학속도론에 의거하여 각각의 연료에 대한 사용수명식을 도출하였다. 도출된 사용수명식으로부터 바이오디젤이 가장 빠르게 산화가 진행되었고 바이오디젤 혼합량이 증가할수록 사용수명이 단축되는 것을 확인할 수 있었다.