• Journal of ILASS-Korea
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• v.15 no.1
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• pp.17-24
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• 2010

The objective of this work is to analyze the macroscopic behavior of spray and injection characteristics on the DME blended biodiesel at different mixing ratios by using spray visualization and injection rate measurement system. The spray images were analyzed to a spray tip penetration, a spray cone angle and a spray area distribution at various mixing ratio of DME by weight. The influence of different injection pressure and ambient pressure on the fuel spray characteristics are investigated for the various injection parameters. In order to analyze the injection characteristics of test fuels, the fuel injection rate is measured at various blending ratio. The variation of viscosity of the blended fuel by the mixing of DME fuel shows the improved effect of spray developments. Also, it was found that the injection quantities of high blended ratio were larger than that of lower blended fuel. Also, higher blending fuel showed a faster evaporation than that of mixing ratio of test fuel because kinetic viscosity was changed by blending ratio.

• Journal of ILASS-Korea
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• v.17 no.3
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• pp.134-139
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• 2012

The main purpose of this study is to analyze and compare the nano-particle emission characteristics by 3-different biodiesel blending rates in a CI engine. Nano-particle number density emitted from various operating conditions of compression ignition engine can be investigated by using the PPS (Pegasor Particle Sensor) system. Namely, some particle charged through the corona discharge in real-time can be measured by PPS system. Under the steady state operation of the 2.0L CRDi diesel engine with different operating condition and biodiesel blending rates, the nano-particle number density was analyzed at the downstream position of DOC system. As this research result, more engine load speed and higher the concentration of biodiesel blending rate showed that the nano-particle number density decreases. Also we found that DOC system for clean diesel engine is effectively useful instrument to reduce diesel particulate matter as resource of nano-particle generation.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.4
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• pp.130-136
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• 2011

This study describes the effect of EGR rate on the combustion and emissions characteristics of a four cylinder CRDI diesel engine using biodiesel (soybean oil) blended diesel fuel. The test fuel is composed of 30% biodiesel and 70% ULSD (ultra low sulfur diesel) by volumetric ratio. The experiment of engine emissions and performance characteristics were performed under the various EGR rates. The experimental results showed that ignition delay was extended, the maximum combustion pressure and heat release gradually were decreased with increasing EGR rate. Comparing biodiesel blended fuel to ULSD, the injection quantity of biodiesel blended fuel was further increased than ULSD. The emission results showed that $NO_x$ emission of biodiesel blended fuel becomes higher according to the increase of EGR rate. However, in the case of biodiesel blended fuel, HC, CO and soot emissions were decreased compared to ULSD.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.140-145
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• 2015

This study was aimed at analyzing NOx conversion characteristics in the HC-SCR with biodiesel content changes of the secondary fuel injection (BD0, BD10, BD25). Test conditions for temperature were set to $290^{\circ}C$, $320^{\circ}C$ and $350^{\circ}C$ considering the upstream temperature of a HC-SCR, distillation of the secondary injected fuels and etc. The amount of fuel injection was adjusted with a fixed space velocity of 55,000(1/h). According to the test results of distillation, the T90 was the same level about $350^{\circ}C$ on all test fuels and the amount of evaporation was reduced at lower than $350^{\circ}C$ temperature condition with increasing biodiesel content. As biodiesel content which is mixed with the secondary injected fuel is increased, NOx reduction efficiency was determined to decrease. The difference of the Nox reduction ratio in a high temperature condition($320^{\circ}C$ and $350^{\circ}C$) than the low temperature($290^{\circ}C$) was more significant. These results are thought to be poor evaporation properties (distillation) and high molecular weight of the biodiesel.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.77-81
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• 2009

Our nature is facing with serious problems related to the air pollution from automobiles in these days. Specially, the exhaust emissions from the diesel engine are recognized as a main cause influencing the environment severly. In this study, the potential possibility of biodiesel fuel is investigated as an alternative fuel for a naturally aspirated CRDi type diesel engine. The smoke emission of biodiesel fuel 5 vol-% was reduced by approximately 40% at 3000 rpm and full load in comparison with diesel fuel. On the other hand, the power, torque and brake specific energy consumption didn't show significant differences. NOx emission of biodiesel fuel was, however, increased compared with commercial diesel fuel.

• Journal of Power System Engineering
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• v.18 no.2
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• pp.5-11
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• 2014

The purpose of this study is to investigate the specific characteristics of combustion and exhaust emissions on a 4-cylinder common rail diesel engine as EGR rate and the rate of blended bio-diesel was altered. Bio-diesel fuel which is a sort of alternative fuels can be adapted to diesel engine directly without modifying. This study was performed to 2000rpm of engine speed with torque 30Nm while EGR rate and the rate of blended bio-diesel was changed. Decreasing combustion pressure and increasing the rate of heat were occurred when we had changed the EGR rate on the 20% of bio-diesel blended diesel fuel. The maximum pressure of combustion and the IMEP became higher as the EGR rate and the rate of blended bio-diesel were changed. Exhaust gas temperature was increased the higher rate of the blended bio-diesel under the fixed EGR rate. However, it went down as the EGR rate increased. The amounts of CO and Soot were reduced with increasing the rate of the blended bio-diesel without changing EGR rate and raised with increasing of the EGR rate. On the fixed EGR rate, NOx was increased along with growing the rate of the bio-diesel. On the other hand, it was decreased while EGR rate were going up.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.26-34
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• 2014

Due to the rapid energy consumption and fossil fuel abundance reduction, the world is progressively in need of alternative and renewable energy sources such as biodiesel. Biodiesel from microalgae offers high hopes to the scientific world for its potential as well as its non-competition with arable lands. Taking consideration to reduce the cost of production as well as to attain twin environmental goals of treatment and use of animal waste material the microalgal cultivation using piggery manure has been tested in this study. Unialgal strains such as Chlorella sp. JK2, Scenedesmus sp. JK10, and an indigenous mixed microalgal culture CSS were cultured for 20 days in diluted piggery manure using Small Scale Raceway Pond (SSRP). Biomass production and lipid productivity of CSS were $1.19{\pm}0.09gL^{-1}$, $12.44{\pm}0.38mgL^{-1}day^{-1}$, respectively and almost twice that of unialgal strains. Also, total nitrogen and total phosphorus removal efficiencies of CSS was 93.6% and 98.5% respectively and 30% higher removal efficiency compared to the use of unialgal strains. These results indicate that the piggery manure can provide microalgae necessary nitrogen and phosphorus for growth thereby effectively treating the manure. In addition, overall cost of microalgal cultivation and subsequently biodiesel production would be significantly reduced.

• KSBB Journal
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• v.11 no.2
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• pp.159-164
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• 1996

Transesterification of used frying oil was investigated to produce the bio-diesel oil. Experimental conditions included molar ratio of used frying oil to alcohol (1:3, 1:5 and 1:7), concentration of catalyst (0.5, 1.0 and 1.5 wt.%), ippe of catalyst(sodium melhoxide, NaOH and KOH), reaction temperature (30, 45 and $60^{\circ}C$), and types of alcohol(methanol, ethanol and butanol). The conversion of used frying oil increased with the alcohol mixing ratio and with the reaction temperature. The effect of the type of catalysts on conversion was not significant. The highest conversion was obtained when methanol was used as alcohol. Viscosity was a little higher with the ester product over grade #2 diesel oil. But the physical properties improved significantly with transesterification, resulting in similar fuel properties with those obtained for grade #2 diesel fuel.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.320-328
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• 2014

Biodiesel has very similar physical properties (density, kinematic viscosity) and has even higher cetane number compare with conventional diesel. There are no necessity to change or modify the infra-structure & engine system. It is known that fatty acid methyl ester (FAME) is oxygen-contained components increasing the combustibility, biodegradability and reduced the exhaust harmful gas. These things made the biodiesel more popular as an alternative diesel fuel. But biodiesel's sources are controversial issues about $CO_2$ reduction effect at this time because those mainly come from edible plants such as soy, palm, rapeseed already spent lot of $CO_2$ to cultivate. Whereas micro-algae is focused because they are inedible and has rapid growth rates & high carbon-dioxide adsorption rate per area. In this study, we analyze the each FAME components using $GC{\times}GC$-TOFMS in stead of GC-FID and verify the previous total FAME contents method's applicability through the micro algal biodiesel derived from Dunaliella tertiolecta.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.183-192
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• 2014

In this work, the mixture formation and atomization characteristics of biodiesel fuel were reviewed under various test conditions for the optimization of compression-ignition engine fueled with biodiesel. To achieve these, the effect of nozzle caviting flow, group-hole nozzle geometry and injection strategies on the injection rate, spray evolution and atomization characteristics of biodiesel were studied by using spray characteristics measuring system. At the same time, the fuel heating system was installed to obtain the effect of fuel temperature on the biodiesel fuel atomization. It was revealed that cavitation in the nozzle orifice promoted the atomization performance of biodiesel. The group-hole nozzle geometry and split injection strategies couldn't improve it, however, the different orifice angles which were diverged and converged angle of a group-hole nozzle enhanced the biodiesel atomization. It was also observed that the increase of fuel temperature induced the quick evaporation of biodiesel fuel droplet.