• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.37-43
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• 2010

The purpose of this paper is to investigate the effect of air-fuel ratio on the combustion and emissions characteristics of spark ignition (SI) gasoline engine fueled with bio-ethanol. A 1.6L SI engine with 4 cylinders was tested on EC dynamometer. In addition, lambda sensor and lambda meter were connected with universal ECU to control the lambda value which is varied from 0.7 to 1.3. The engine performance and combustion characteristics of bio-ethanol fuel were compared to those obtained by pure gasoline. Furthermore, the exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), oxides of nitrogen ($NO_X$) and carbon dioxide ($CO_2$) were measured by emission analyzers. The results showed that the brake torque and cylinder pressure of bio-ethanol fuel were slightly higher than those of gasoline fuel. Brake specific fuel consumption (BSFC) of bio-ethanol was increased while brake specific energy consumption (BSEC) was decreased. The exhaust emissions of bio-ethanol fuel were lower than those of gasoline fuel under overall experimental conditions. However, the specific emission characteristics of the engine with bio-ethanol fuel were influenced by air-fuel ratio.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.358-364
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• 2016

The combustion and exhaust emission characteristics in a spark ignition (SI) engine with various test fuels (bioethanol - gasoline blends) and air-fuel ratio were investigated in this research. To investigate the influence of the excess air ratio and ethanol blends on the combustion characteristics such as the cylinder pressure, rate of heat release (ROHR), and fuel consumption rate were analyzed. In addition, the reduction effects of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and oxides of nitrogen (NOx) were compared with those of neat gasoline fuel under the various excess-air ratios. The results showed that the peak combustion pressures and the ROHR of bioethanol fuel cases were slightly higher than those of gasoline fuel at all test ranges and fuel ratio. As compared with gasoline fuel (G100) at each given excess air ratio, BSFC of bio-ethanol was increased. The CO, HC, NOx emissions of bio-ethanol blends were lower than those of gasoline fuel under overall experimental conditions.

• Journal of Hydrogen and New Energy
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• v.20 no.2
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• pp.142-150
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• 2009

This paper presents bio-ethanol production from fruit wastes as it possibly alternate fossil fuel in the future. To illustrate the component ratio in exocarps of fruit wastes such as pears, apples, and persimmons, the amount of moisture, lignin, $\alpha$, $\beta$, $\gamma$-cellulose, and ash content were respectively examined by the ingredient analysis. Also, the amount of the glucose obtained from the enzyme hydrolysis using the axocarps was investigated. It was found in our results that the energy efficient process requires different temperature conditions for the saccharification step($50^{\circ}C$ and the fermentation step($30^{\circ}C$ in ethanol synthesis.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.111.1-111.1
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• 2011

Recently, comsumption of fossil fuel is causing many problems(oilflation, global warming, environmental pollution). For this reason Renewable energy is now becoming the center of interest as a solution to these problems. Bioethanol, especially, is able to substitute petroleum as fuel; making it a viable and promising renewable energy. In order to production of fuel bioethanol, Dehydration process is essential. Azeotropic distillation, extractive and pressure swing absorption(PSA) process are some of possible dehydration process, out of which, PSA process is attractive since it required less energy and lower setup cost. In this study, we produced fuel bioethanol using 2-step PSA(3 bed + 2 bed) process for more efficient and economical process. Through this study, we produced fuel bioethanol using 2-step PSA process and concentration of fuel bioethanol was 99.54wt%(feed ethanol: 92.4wt%). We expected that because of efficient use of absorbents(zeolite), 2 step PSA process contribute to economical operation.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.107-112
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• 2011

FFV(Flexible Fuel Vehicle) is the vehicle that can be used liberally from gasoline to E100(Ethanol 100%) for fuel. Recently, interest in the bio-fuel is increased by the environmental factors like exhaustion of the fossil fuel and ruduction of greenhouse gases. For the reason, adopting of FFV is activated in the world including North and South America. In general, bio-ethanol has highly corrosive substance in compare with gasoline. In the part of fuel system, corrosion can make a safety problem in case of fuel leakage and engine starting problem. So the fuel system of FFV have to be made of high corrosion-resistant materials. This study examined the effect of bio-ethanol on the durability properties according to component materials in FFV fuel pump motor and regulator using the High Temperature Fuel Circulation Test.

• Membrane Journal
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• v.32 no.6
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• pp.383-389
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• 2022

Membrane separation process is an important technique utilized for various applications. This separation process proceeds due to a driving force such as concentration gradient, pressure or electrical potential gradient etc. Pervaporation is one of the separation process based on solution-diffusion mechanism. The pressure of the permeate side is reduced by creating vacuum and separation is driven due to pressure difference. Purity of the fuel or chemical like ethanol or isopropyl alcohol are improved by dehydration process through porous zeolite membrane. These membranes have high thermal, chemical, mechanical stability. This review is classified mainly into two different sections: Ethanol and bio-oil dehydration by zeolite membrane.

• KSBB Journal
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• v.10 no.1
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• pp.105-112
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• 1995

The fiber-optic biosensor using enzyme-immobilized Langmuir-Blodgett film is developed fort the measurement of ethanol. The enzyme, alcohol dehydrogenase, is immobilized at the molecular level on the arachidic acid monolayer using Langmuir-Blodgett film technique. Based on the ordered multisubstrate mechanism, the immobilized enzyme kinetics is investigated. The optical sensing system is proposed, and sensor signal is proportional to ethanol concentration and is related wish the number of enzyme layers. As the number of deposited LB film layer increases up to 20 1ayers, the high ethanol concentration of 45mM can be measured without the saturation of signal. Surface pressure-area isotherm is measured for the three-different charged-lipids. Arachidic acid is the most suitable for the adsorption of alcohol dehydrogenase based on electrostatic force.

• Journal of Life Science
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• v.29 no.8
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• pp.916-921
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• 2019

In this study, we constructed a biological system that exhibited thermotolerance, ethanol tolerance, and increased ethanol productivity using a random mutagenesis method. We attempted to isolate a thermotolerant mutant using proofreading-deficient DNA polymerase ${\delta}$ and ${\varepsilon}$ encoded by the pol3 and pol2 genes, respectively, in Saccharomyces cerevisiae. To obtain mutants that could grow at high temperatures ($38^{\circ}C$ and $40^{\circ}C$), random mutagenesis of AMY410 (pol2-4) and AMY126 (pol3-01) strains was induced. The parental strains (AMY410 and AMY126) grew poorly at temperatures higher than $38^{\circ}C$. By stepwise elevation of the incubation temperature, AMY410-Ht (heat tolerance) and AMY126-Ht strains that proliferated at $40^{\circ}C$ were obtained. These strains were further incubated in medium containing 6% and 8% ethanol and then AMY410-HEt (heat and ethanol tolerance) and AMY126-HEt strain with ethanol tolerance at an 8% ethanol concentration was obtained. The AMY126-HEt strain grew even at an ethanol concentration of 10%. Furthermore, following the addition of high concentrations of glucose (5% and 10%), an AMY126-HEt3 strain with increased ethanol productivity was isolated. This strain produced 24.7 g/l of ethanol (95% theoretical conversion yield) from 50 g/l of glucose. The findings demonstrate that a new biological system (yeast strain) showing various phenotypes can be easily and efficiently bred by random mutagenesis of a proofreading- deficient mutant.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.646-652
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• 2016

Biomass is regarded as one of the promising energy sources to deal with the depletion of fossil fuels and the global warming issue. Biocrude-oil can be produced through the fast pyrolysis of biomass feedstocks such as wood, crops, agricultural and forestry residues. It has significantly higher viscosity than that of conventional petroleum fuel and contains solid residues, which can lower the spray and atomization characteristics when applied to the burner. In addition, biocrude-oil consists of hundreds of chemical species derived from cellulose, hemicellulose and lignin, and evaporation characteristics of the biocrude-oil droplet are distinct from the conventional fuels. In the present study, a numerical study was performed to investigate the evaporation characteristics of biocrude-oil droplet using a simplified composition of the model biocrude-oil which consists of acetic acid, levoglucosan, phenol, and water. The evaporation characteristics of droplets were compared at various surrounding air temperatures, initial droplet diameters, and ethanol mixing ratios. The evaporation time becomes shorter with increasing air temperature, and it is much sensitive to the air temperature particularly in low temperature ranges. It was also found that the biocrude-oil droplet evaporates faster in cases of the smaller initial droplet diameter and larger ethanol mixing ratio.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.415-424
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• 2020

In the present study, we have refined gomisin N, which represents activity in the proliferation of dermal papilla cells (HFDPCs) from the fruit of Schisandra chinensis (S. chinensis), and have identified optimal extraction conditions for obtaining extracts with high content of gomisin N. The activity of the extracts and fractions was evaluated, and the results indicated approximately 29% proliferation activity in the group treated with 1 ㎍/mL of n-hexane fraction. Column chromatography was used to assess the active ingredient in the n-hexane fraction, and two compounds, namely gomisin N(1) and schisandrin(2), were isolated and identified. When the HFDPCs proliferation activity was tested for the isolated compounds, gomisin N exhibited ≥ 20% proliferation activity. Thus, via response surface methodology (RSM), the optimum extraction conditions to obtain the maximum level of gomisin N from the fruit of S. chinensis were determined, where ethanol proportion, extraction time, and extraction temperature were used as the independent variables. The results revealed coefficient of determination ≥ 0.95 and p-value ≤ 0.05, which confirmed the fit of the model. The optimum extraction conditions to achieve the maximum content of gomisin N were as follows: ethanol proportion 83.8%, extraction temperature 80 ℃, and extraction time 8.7 h. The content of gomisin N using these conditions was predicted as 378,300 ppm, and a mean value close to the predicted value (376,884 ppm) was obtained while validating the aforementioned conditions.