• Transactions of the Korean hydrogen and new energy society
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• v.22 no.2
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• pp.257-264
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• 2011

This study discribes performance of DEFC (Direct Ethanol Fuel Cell) utilized bio-ethanol based on fruit wastes. To produce the bio-ethanol, fruit wastes were treated at temperature $120^{\circ}C$ and 90minutes in acid pre-treatment. After pre-treatment was done, alcohol fermentation process was running. Initial alcohol concentration was 5%. Using the multi coloumn distillation system, more than 95% ethanol was distilled and each component of bio-ethanol was analyzed. In DEFC performance test, it was revealed that cell performance was much higher than that of ethanol. Comparing ethanol with mixed fuel (bio-ethanol (10%) + ethanol (90%)), the performance of ethanol was higher than that of mixed fuel. Even though the bio-ethanol from the fruit wastes is corresponded with transport ethanol standards, it thought that organic matter in bio-ethanol could be negative effect on fuel cell.

• Journal of the Korean Society of Combustion
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• v.18 no.4
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• pp.12-20
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• 2013

The ignition delay time is an important factor to understand the combustion characteristics of internal combustion engine. In this study, ignition delay times of cool and thermal flame were observed separately in homogeneous charge compression ignition(HCCI) engine. This study presents numerical investigation of ignition delay time of n-heptane and alcohol(ethanol and n-butanol) binary fuel. The $O_2$ concentration in the mixture was set 9-10% to simulate high exhaust gas recirculation(EGR) rate condition. The numerical study on the ignition delay time was performed using CHEMKIN codes with various blending ratios and EGR rates. The results revealed that the ignition delay time increased with increasing the alcohol fraction in the mixture due to a decrease of oxidation of n-heptane at the low temperature. From the numerical analysis, ethanol needed more radical and higher temperature than n-butanol for oxidation. In addition, thermal ignition delay time is sharply increasing with decreasing $O_2$ fraction, but cool flame ignition delay time changes negligibly for both binary fuels. Also, in high temperature regime, the ignition delay time showed similar tendency with both blends regardless of blending ratio and EGR rate.

• Journal of Electrochemical Science and Technology
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• v.14 no.4
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• pp.303-310
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• 2023

Microbial fuel cells (MFCs) are a bioelectrochemical system where electrochemically active bacteria convert organic waste into electricity. Poly(vinyl alcohol) (PVA) and chitosan (CS) are polymers that have been studied as potential alternative ion exchange membranes to Nafion for many electrochemical systems. This study examined the optimal mixing ratio of PVA and chitosan CS in a PVA:CS composite membrane for MFC applications. PVA:CS composite membranes with 1:1, 2:1, and 3:1 ratios were synthesized and tested. The water uptake and ion exchange capacity, Fourier transform infrared spectra, and scanning electron microscopy images were analyzed to determine the physicochemical properties of PVA:CS membranes. The prepared membranes were applied to the ion exchange membrane of the MFC system, and their effects on the electrochemical performance were evaluated. These results showed that the composite membrane with a 3:1 (PVA:CS) ratio showed comparable performance to the commercialized Nafion membrane and produced more electricity than the other synthesized membranes. The PVA:CS membrane implemented MFCs produced a maximum power density of 0.026 mW cm^-2 from organic waste with stable performance. Therefore, it can be applied to a cost-effective MFC system.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.288-294
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• 1990

Two pure fuel oils(#1 oil, #6 oil), theree pure alcohols (methanol, ethanol, propanol) were tested for the fuel characteristics such as miscibility (that established which pure fuels and fuel mixtures could be fired in the boiler), flash point, viscosity. Specific target of the study besides the oil/alcohols or oil/alcohol mixture without any modification and with safety. #1 oil could be mixed without any problems at all concentrations with two of the alcohols; these were the ethanol and propanol. However, miscibility of #6 oil with any alcohols and #1 oil with methanol was not possible and very limited in this study. The measurements of flash point and viscosity for the mixtures were done for the comparisons with the pure fuels. There was a marked change of flame shape and flame luminosity as the alcohol content of the mixtures was increased. The mixture flame shortened and became non-luminous compared with a pure fuel oil flame.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.154-161
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• 2015

A novel process has successfully been developed by overcoming major difficulties through the elimination of number of process steps involved in the Classical Transesterification reaction during the preparation of Fatty Acid Methyl/Ethyl Ester (FAME.FAEE) called biodiesel. The Classical process with cost intensive process steps such as the utilization of excess alcohol, needing downstream distillation for the recovery and reutilization of excess alcohol/cosolvent, unrecoverable homogenous catalyst which consumes vast quantity of fresh distilled water during the purification of the product and downstream waste water treatment before its safe disposal to the surface water body. The Novel Process FAME/FAEE is produced from any vegetable oil irrespective of edible or inedible variety using sonication energy. The novelty of the finding is the use of only theoretical quantity of alcohol along with a co-solvent and reduced quantity of homogeneous catalyst. Under this condition neither the homogeneous catalyst goes to the FAME layer nor is the distillation needed. The same ester also has been prepared in high pressure high temperature reactor without using catalyst at sub critical temperature. The quality of prepared biodiesel without involving any purification step meets the ASTM standards. Blended Biodiesel with Common Diesel Fuel (CDF) and FAME is prepared, characterized and used as fuel in the Kirloskar make CI Engines. The evaluation of the engine performance result of pure CDF, B05 biodiesel, B10 biodiesel of all types of biodiesel prepared by using the feedstock of Soybean (Glycine max) and Karanja (Pongamia pinnate) oil along with their mixed oil provides useful information such as brake power, brake thermal efficiency, brake specific fuel consumption, etc, and established it as ideal fuel for unmodified CI engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.71-78
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• 2001

This paper presents the results of an experimental investigation on the combustion of single droplets arrays of Ethyl alcohol and kerosene fuel droplets in atmospheric pressure. The initial droplet diameters, d$_{0}$, were nominally 1.3~1.8mm, and inter-droplet separation distance l(l/do=1.31~2.60). experimental results indicate that burning rate constants(K) of ethyl alcohol and kerosene droplets were independent of initial droplet size as 0.0083, 0.0095 $\textrm{cm}^2$/sec. For 1-D droplet array's kerosene fuel droplet, burning rate constants(K) decreases with decreasing normalized inter-droplet distance. Normalized inter-droplet distance has stronger effect on 2nd fuel droplet than 3rd fuel droplet. When normalized inter-droplet distance is larger than 2.60, the effect of droplet spacing on droplet life is very small.

• 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.

• Macromolecular Research
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• v.14 no.4
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• pp.449-455
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• 2006

Ionic cluster mimic, polymer electrolyte membranes were prepared using polymer composites of crosslinked poly(vinyl alcohol) (PVA) with sulfated-${\beta}$-cyclodextrins (${\beta}-CDSO_3H$) or phosphated-${\beta}$-cyclodextrins (${\beta}-CDPO(OH)_2$). When Nafion, developed for a fuel cell using low temperature, polymer electrolyte membranes, is used in a direct methanol fuel cell, it has a methanol crossover problem. The ionic inverted micellar structure formed by micro-segregation in Nafion, known as ionic cluster, is distorted in methanol aqueous solution, resulting in the significant transport of methanol through the membrane. While the ionic structure formed by the ionic sites in either ${\beta}-CDSO_3H$ or ${\beta}-CDPO(OH)_2$ in this composite membrane is maintained in methanol solution, it is expected to reduce methanol transport. Proton conductivity was found to increase in PVA membranes upon addition of ionized cyclodextrins. Methanol permeability through the PVA composite membrane containing cyclodextrins was lower than that of Nafion. It is thus concluded that the structure and fixation of ionic clusters are significant barriers to methanol crossover in direct methanol fuel cells.

• Journal of the korean Society of Automotive Engineers
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• v.24 no.4
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• pp.47-49
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• 2002

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.380-388
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• 2017

Wood pyrolysis oil(WPO) has been regarded as an alternative fuel for diesel engines. However, WPO is not feasible for use directly in diesel engines due to its poor fuel quality such as low energy density, high acidity, high viscosity and low cetane number. The most widely used approach to improve WPO fuel quality is to blend WPO with other hydrocarbon fuels that have a higher cetane number. However, WPO and fossil fuels are not usually blended because of their different polarity. Also, clogging and polymerization problems in the fuel supply system can occur when the engine is operated with WPO. Polymerization can be prevented by diluting WPO with other alcohol fuels. However, WPO-alcohol blended fuel does not produce self-ignition. Therefore, additional cetane enhancement to the blended fuel is required to enhance auto-ignitability. In this study, WPO was blended with n-butanol and two cetane enhancements(PEG 400 and 2-EHN) for application to a diesel generator. Experimental results showed that the WPO-butanol blended fuel achieved a very stable engine operation under maximum WPO content of 20 wt%.