• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.487-492
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• 2013

Transesterifications of waste oils mixed with animal tallows and vegetable oil by ultrasonic energy were examined over various catalysts for biodiesel production. Reaction activities of the transesterification were evaluated to the ultrasonic energy and thermal energy. The physicochemical properties of feedstock and products were also investigated to the biodiesels produced from the oils in the reaction using ultrasonic energy. The highest fatty acid methyl ester (FAME) yield was obtained on the potassium hydroxide catalyst in the transesterification by ultrasonic irradiation. The effective reaction conditions by ultrasonic energy were 0.5 wt% catalyst loading and 6:1 molar ratio of methanol to the mixed oils. The reaction rate of the transesterification by ultrasonic energy was faster than that by thermal energy. The highest yields of FAME were obtained as 80% in 5 min and the reaction equilibrium reached at that time.

• Journal of Marine Bioscience and Biotechnology
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• v.11 no.1
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• pp.23-28
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• 2019

For successful microalgal biodiesel production, the strain should be selected carefully. Fast growth rate and high fatty acid contents are desired traits for algal biodiesel production. In ocean cultivation of microalgae, seawater temperature slowly changes over seasons, and rotating algal strains in accordance with their optimal temperature could improve overall productivity. Additionally, use of indigenous strain is preferred to alleviate potential impacts on the environment. In this study, five strains of Tetraselmis sp. from nearshore of Youngheung Island, Incheon, Korea, were isolated during winter and characterized for their growth patterns and fatty acid compositions in the low temperatures ($5-15^{\circ}C$). The five strains showed various characteristics in optimal growth temperature, fatty acid contents, and compositions. Compared with a strain of Tetraselmis sp., isolated from Ganghwa island in a previous study, a rapid-growing strain with 237% higher biomass productivity and an oleaginous strain with twice higher fatty acid contents at $10^{\circ}C$ were isolated. The oleaginous Tetraselmis strain showed the highest fatty acid productivity among the strains, having 438% higher productivity than the previous strain. Using the new isolates in the seasons with low seawater temperature would improve microalgal fatty acid productivity in ocean cultivation.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.127-128
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• 2003

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.64-69
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• 2016

The applications of heterogeneous catalyst have been relatively active area of research in the biodiesel process. These catalysts have the benefit of easy recovery and reusability of the catalyst. The objective of this study is to find out significant effect of calcination temperature on $K_2CO_3/{\gamma}-Al_2O_3$ catalytic activity in the biodiesel formation reaction. As a results, the temperature at which a catalyst was calcined had very important influence on the catalytic activity. The catalytic activity increased up to $600^{\circ}C$, but it severely decreased above the temperature. The reduction of catalyst activity at high temperature would be due to the deduction of the active sites of Al-O-K and $Al-O_2-K$.

• Environmental and Resource Economics Review
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• v.18 no.1
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• pp.23-51
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• 2009

This research alms at quantifying economic impacts of free trading policy on environment-friendly fuel industry applying a static general equilibrium (CGE) model for Korea. Theoretically, 'polluters haven' hypothesis had been debated as major issue on the environmental effects of trade liberalization during 1970s and 1980s but recent literature emphasizes that production, scale, structural, and regulatory effects may derive rapid diffusion of environment friendly technologies. In this study, trade liberalization policy affects output of agricultural sectors negatively while that of biodiesel as environment-friendly technology positively. The rise m the output of biodiesel is derived from the reduction in import prices of agricultural products due to the abolishment of tariff. The policy implication from the analysis is that feedstock for producing biodiesel should be exploited in the foreign countries where productivity of agriculture is quite predominant compared to Korean agriculture.

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.508-516
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• 2011

Hydrotreated biodiesel(HBD) is paraffinic bio-based liquid, with the chemical structure $C_nH_{2n+2}$, originating from vegetable oil(the process can also be applied to animal fat). The oil or fat is treated in a number of process, the most important being hydrogenation, in order to create a bio-based liquid diesel fuel. During the hydrogenation, oxygen is removed from the triglyceride and converted into water. Propane is formed as a by product and can be combusted and used for energy production. HBD can be used in conventional diesel engines, pure or blended with conventional diesel, due to its similar physical properties to diesel. This study reports the quality characteristics with chemical and physical properties as an alternative diesel fuel. Especially, HBD showed higher cetane value and number than FAME, and it is consisted of $C_{15}$ - $C_{18}$ n-paraffinic compounds. We also describes quality characteristics of HBD blends(2, 5, 10, 20, 30, 40, 50 vol%) in automotive diesel. HBD blends(max. 20 vol%) were the limit by the Korean specification due to poor low temperature characteristics.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.759-765
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• 2012

As the biodiesel production is increasing rapidly, the crude glycerol, which is principal by-product of biodiesel production, has also been generated in a large amount. Many research studies on value-added utilization of glycerol are under investigation. 1,3-Propandiol is a promising chemical which can be produced from fermentation of glycerol because the application of 1,3-propanediol is mainly in the production of bio-PTT (Poly(trimethylene terephthalate). However, the cost of downstream processes in the biological production of 1,3-propanediol can make a high portion in the total production cost. This review summarizes the present state of separation processes in each step studied for the removal of impurities and the recovery of 1,3-propanediol from its fermentation broth. Furthermore, ATPE (Aqueous Two Phases Extraction) process is suggested as an attractive alternative for the primary separation process of 1,3-propanediol because ATPE is convenient for the simultaneous removal of microbial cells and impurities such as salts of organic acids and the separation of 1,3-propanediol from fermentation broth.

• KSBB Journal
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• v.25 no.4
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• pp.363-370
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• 2010

Lipid from Scenedesmus sp. was extracted, fractionated and purified by silicic acid column chromatography. Total lipid content of extract was $21.38{\pm}1.03$ wt%, and triacylglycerol, an index lipid for biodiesel production was detected. Ten species of $C_{16}{\sim}C_{22}$ with saturated and unsaturated fatty acid were identified showing the very adequate fatty acid profiles for biodiesel production with a good flow property at low temperature. The fractions of glycolipid, neutral and phospholipid were 52.64, 28.10 and 19.26% of total lipid, respectively. The triacylglycerol of 12.63% and chlorophyll a of 49.47% was fractioned using stepwise elution of n-hexane-diethyl ether (95:5, v/v) solvent. The high content of chlorophyll was considered as a potential source of value-added co-product.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.288-294
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• 2013

Recently, sustainable production of biofuel using algal biomass is being pursued because of its enormous potential. First and foremost, securing superior strains to develop an efficient production system for algal biodiesel through screening or genetic improvement of microalgae is necessary. The genus of Botryococcus is regarded as one of the superior microalgae for biodiesel production due to its ability to accumulate high amounts of lipids and hydrocarbons. However, its low growth rate is a bottleneck for large-scale production and commercialization. The purpose of this study is to obtain indigenous Botryococcus strains which possess high lipid content and biomass productivity. The Botryococcus sp. was isolated from the Seobu Reservoir in Jeju Island and identified as Botryococcus sudeticus J2 by comparative analysis of 18s rRNA gene and ITS regions. The biomass productivity and lipid content of B. sudeticus J2 were 0.116 g $L^{-1}day^{-1}$ and 40.1% of dry wt., respectively. This was higher than the value of B. braunii UTEX 572, which is widely regarded as a superior strain among Botryococcus species. The relatively high growth rate of B. sudeticus J2 was achieved under a light intensity of 240 ${\mu}mol$ photons $m^{-2}s^{-1}$ with ambient air spargingwhen compared to 120 ${\mu}mol$ photons $m^{-2}s^{-1}$ with 2% $CO_2$ supply. In summary, it is likely that the isolated B. sudeticus J2 can be used for the mass cultivation and biodiesel production.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.177.1-177.1
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• 2011

국내 바이오디젤의 원료로 사용되는 식물성 오일은 거의 전량이 수입된 것으로 원료를 자급화 하기 위한 방안으로 국내 동물성 폐자원을 이용한 바이오디젤 연구가 활발히 진행되고 있다. 본 연구에서는 전자레인지를 이용해 동물성 폐자원인 폐돈지 및 폐우지로부터 오일을 추출 후 물성을 분석하고 전이에스테르화 반응을 진행하였으며 바이오디젤 제조 특성을 조사하고자 하였다. 전이에스테르화 반응에 사용되는 염기 촉매를 몇가지 선정하여 각각의 촉매에 따른 바이오디젤의 반응특성을 메탄올 양을 변화시키며 조사 실험하였다. 기존에 사용된 바이오디젤 제조 촉매는 KOH를 주로 사용하였으며 본 연구에서는 KOH, NaOH, $NaOCH_3$를 촉매로 사용하여 오일질량 대비 0.8~1.2%의 촉매를 사용하였으며 메탄올의 양은 오일 몰수 대비 6:1~12:1의 비율로 사용하여 반응시간에 따른 반응특성과 제조 바이오디젤의 물성을 분석해 각 촉매에 따른 바이오디젤 생산 특성을 비교분석하였다.