• Transactions of the Korean hydrogen and new energy society
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• v.27 no.4
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• pp.447-461
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• 2016

Recently, the Renewable Fuel Standard(RFS) has been commenced from July 31, 2015 in the New and Renewable Energy Act for expanding the supply of renewable energy and reduction of national GHG target in Korea. The biodiesel is only a means of implementation for the RFS, therefore the biodiesel supply expansion is important for fulfilling the RFS obligation policy. The major key points of the biodiesl supply are expanding domestic feedstocks due to the over 60% dependence on foreign feedstock and reducing the price of feedstock because of the over 70% occupation of feed stock price in the biodiesl production cost. Therefore, we estimated actual amount of potential feedstocks which are possible to use for biodiesl production in Korea and investigated technical and political improvements for expanding biodiesl. For estimating a potential feedstocks, first selected the potential biodiesl feedstocks by investigating the status of global biodiesl feedstocks and then analyzed the possible potential amount of each feedstock by surveying the generation situations, the distribution structures and the technical level.

• KSBB Journal
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• v.25 no.1
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• pp.1-10
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• 2010

Biodiesel is a type of biofuel obtained from bioresources and able to use in diesel vehicles as an alternative/additive to petro diesel. In recent biodiesel research, there are three main issues which include high quality biodiesel, low cost feed stock and a highly efficient biodiesel production process. The sustainable production and use of biodiesel are attracting much attention in the renewable energy field. In this paper, we review some of the literatures related to environmental and economic evaluation for biodiesel production and analysis the issues including life cycle assessment (LCA), global warming potential (GWP), energy consumption, biodiesel production cost, production technologies and feedstock.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.129-138
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• 2008

Demand for alternatives to petroleum is increasing the production of biofuels from food crops such as corn, soybeans, sorghum and sugarcane, etc. At least for the next 5 years, ethanol demand will be increased greatly in the United States and in the world. Presently, most ethanol produced in the United States is corn (Zea mays) ethanol. As a result, especially in the Americas and Southeast Asia, agricultural land is diverted to biofuel production. Even though biofuel industry has many advantage including national security, economical, energetical and sustainable impacts, it is driving grain prices up and creating considerable concern about the potential negative impacts on a wide range of food products that depend on gain : chicken, pork, beef, and dairy products such as milk, cheese, yoghurt, cream and ice cream. Feedstock crops are crops such as switchgrass(Panicum virgatum, L.), corn stover and grasses that can be used in industrial processes such as fermentation into alcohol fuels. Feedstock is no compete with food. Furthermore it is friendly environmental bioenergy crops. In Korea, with increasing demand for fossil fuels the exploration of alternative sources of liquid fuel is inevitable. I suggest Korea need to research and to develop actively on feedstock for biofuel production through this review.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.688-700
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• 2013

The potential of biodiesel production technology using lipids extracted from sewage sludge was investigated. Despite the bright prospect of biodiesel production, efforts to commercialize it have been very limited. One of the major obstacles has been the high price associated with refined oil feedstock, which makes up nearly 70-75% of the total production costs. Hence, in order to reduce the cost of biodiesel production, using cheaper feedstock such as waste oil or low-quality oil has been proposed. Especially, sewage sludge, a relatively inexpensive feedstock, is a promising raw material for such a purpose. In this study, it is aimed to review biodiesel production technology from sewage sludge as a lipid feedstock. It is process modifications to combine the oil extraction steps, fuel conversion steps (i.e. in situ transesterification, thermo-chemical process with non-catalytic heterogeneous biodiesel production) and fuel quality from sewage sludge.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.74-83
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• 2020

Organic waste used as a feedstock in the anaerobic digestion (AD), it includes carbon and nitrogen. Carbon and nitrogen have an effect on the various digestive characteristics during AD, however, the study is rare about those of the interaction. This study investigates the influence of carbon type and carbon to nitrogens (C/N ratios) on the AD characteristics of organic waste. Experimental treatments involved a combination of three carbon types with three C/N ratios. The AD tests were carried out using a 125-mL serum bottle at a constant temperature of 37℃ and moisture 95% for 18 days. Degradation pattern shows the difference among three-carbon treatments, the starch group was faster than other groups. Maximum methane production date was similar between starch (9.96 ± 0.05 day) and xylan group (10.0 ± 0.52 day), those of the cellulose group (14.6 ± 1.80 day) was slower than other groups (p < 0.05). The lag phase was only affected by the carbon type (p < 0.05). Ammonia nitrogen was mainly affected by nitrogen concentration regardless of carbon type (p < 0.05). This study showed that xylan is useful as feedstock in order to decrease the lag phase, and it showed that ammonia was independently affected by the nitrogen concentration.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.418-421
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• 2006

Fatty acid methyl esters, also referred to as biodiesel, have been determined to have a great deal of potential as substitutes for petro-diesel. In order to enhance productivity in the biodiesel production process, feedstocks were previously recommended to be anhydrous, with a free fatty acid content of less than 0.5%. In this study, the effects of several catalysts, methanol molar ratio, catalyst amount, and reaction time on the reduction of free fatty acid level were studied with a simulated feedstock consisting of 20% oleic acid in rapeseed oil. Ferric sulfate was selected as the best catalyst. Increasing the catalyst amount and methanol molar ratio is very effective in decreasing the acid value of the simulated mixture. Our results may provide useful information with regard to the development of more economic and efficient free fatty acid removal system.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.793-807
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• 2020

The policy for Green New Deal will promote the shift of the application to coal as feedstock from coal as fuel. Coal can be used as fuel for production of hydrogen and as feedstock materials such as synthetic graphite or activated carbon. Hydrogen is obtained from syngas produced through Steam carbon(SC), Water-Gas Shift(WGS), and Carbonation reactions, and these processes should be used in conjunction with CO2 sequestration technology. Anthracite has a potential in terms of cost advantage as a feedstock compared to a petroleum pitch, because Synthetic graphite is prepared by heat treating an anthracite with high rank to a graphitization temperature which is in the range of 2400~2800℃, in the presence of inorganic catalyst such as silicon or iron. From several studies, it has been confirmed that coal-based activated carbon(AC) is manufactured with quality similar to the large specific surface area and much micropore volume of lignin-based AC, can be prepared. Therefore it is expected that lignin-based AC is replaced to coal-based AC.

• KSBB Journal
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• v.31 no.1
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• pp.79-84
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• 2016

Biofuel has been considered as promising renewable energy to solve various problems that result from increasing usage of fossil fuels since the early 20th century. In terms of chemical and physical properties as fuel, biobutanol has more merits than bioethanol. It could replace gasoline for transportation and industrial demand is increasing significantly. Production of butanol can be achieved by chemical synthesis or by microbial fermentation. The water hyacinth, an aquatic macrophyte, originated from tropical South America but is currently distributed all over the world. Water hyacinth has excellent water purification capacity and it can be utilized as animal feed, organic fertilizer, and biomass feedstock. However, it can cause problems in the rivers and lakes due to its rapid growth and dense mats formation. In this study, the potential of water hyacinth was evaluated as a lignocellulosic biomass feedstock in biobutanol fermentation by using Clostridium beijerinckii. Water hyacinth was converted to water hyacinth hydrolysate medium through pretreatment and saccharification. It was found that productivity of water hyacinth hydrolysate medium on biobutanol production was comparable to general medium.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.338-347
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• 2021

Polyhydroxyalkanoates (PHA) are a family of microbial polyesters that are used as biodegradable plastics in replacement of conventional plastics for various applications. However, the high production cost is the barrier for PHA market expansion. This study aimed to utilize food waste as low-cost feedstock to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by Haloferax mediterranei. The effects of acetate (Ac), propionate (Pr), butyrate (Bu), and the short-chain carboxylates derived from food waste were examined on the microbial growth and PHBV production. Results showed that a mixture of carboxylates provided a 55% higher PHBV yield than glucose. The food-waste-derived nutrients achieved the yields of 0.41 to 0.54 g PHBV/g Ac from initial loadings of 450 mg/l to 1,800 mg/l Ac of total carboxylates. And the consumption of individual carboxylate varied between different compositions of the carbon source. The present study demonstrates the potential of using food waste as feedstock to produce PHBV by Haloferax mediterranei, which can provide economic benefits to the current PHA industry. Meanwhile, it will also help promote organic waste reduction in landfills and waste management in general.

• Journal of Power System Engineering
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• v.8 no.4
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• pp.38-43
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• 2004

Thermal spraying onto the metal substrate has been widely used as a technique of the surface treatment in the various industrial field. A wide range of thermal spray technologies exist and all rely on the fundamental process of fusing a metal feedstock, atomizing it and transporting it to the surface of a substrate. Specially, these methods have been taken into account as the protection method against the corrosion. In this study, the polarization characteristics were carried out on the thermal sprayed coating layer immersed in various pH of diluted aqueous solutions at $25^{\circ}C$. Aluminum, Zinc, Ni-base alloy, alumina and polyethylene powder were used with sprayed coating materials. From the polarization curves, the electrochemical corrosion potential($E_{corr}$) and the corrosion current density($I_{corr}$) were investigated.