• 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.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.197-202
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• 1994

Microalga, Spirulina platensis has been cultivated in a pilot scale photo-bioreactor to treat wastewater and to produce high protein feedstocks from swine waste containing medium. 0.31(1/day) of specific growth rate and 0.170 of bioenergeric yield were obtanined from batch cultivation in 30% waster containing medium, compared to 0.71(1/day) and 0.545 from clean culture. An optimal dilution concentration was decided as 20% of working volume, based upon the cell growth and biomass productivity. The removal rate of nitrates in the wastewater was decreased as the adding concentration of wastewater was increased while the decrease of total phosphates was reversed, showing 0.33(1/day) and 0.30(1/day) of rate constants for nitrate removal in 10% addition and for phosphate removal in 30% addition, respectively. The chemical composition and amino acid profile of the biomass were superior to those of commerically available health food product, Spirulina sp.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.176-176
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• 2005

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.4
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• pp.386-403
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• 2016

Biofuels produced from biomass can be substituted for petroleum fuels due to GHG reduction, sustainability and environmental friendly. The process technologies that convert biomass into biofuels are varied and depend on the feedstocks. Microalgae are considered to be one of the most promising alternative source to the conventional feedstocks for biofuel. Microalgae can be converted to biodiesel, bioethanol, biogas and biojet fuel via thermolchemical and biochemical production technologies. This reviews discusses recent advance in understanding the effects of the characteristics of various processes on the production of biofuels using microalgae. The performances of microalgae based biofuel are compared.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.41-42
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• 2006

Small powder size is very useful in achieving detailed structures. STS 316 nanopowders with an average diameter of 100 nm and $5{\mu}m$ were utilized to produce feedstock. The mixing behavior of the feedstock indicated that the nanoparticle feedstock produced the highest mixing torque at various powder loading compared to the micropowder feedstock. The nanoparticles feedstocks showed that elastic properties are dominant in flow behavior and high viscosity. Conversely the micropowders feedstocks, viscous properties are dominant in flow behavior and less viscosity, nanopowders feedstock perform lower flow activation energy than feedstock with bigger particles.

• The Korean Journal of Rheology
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• v.11 no.1
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• pp.57-65
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• 1999

In order to measure yield stress of PIM feedstocks simply and effectively, a yield stress measuring technique was developed by a vane method. The vane method had an advantage that there was no wall-slip, while it had a drawback that it could not measure viscosity change at various shear rates. A Newtonian fluid was tested for the appropriateness of the measuring technique. The end effect of a vane was checked to produce an acceptable error. The torque peak has been considered to be developed at yielding of non-Newtonian fluids with yield stress. However, it was influenced very much by control system of the instrument so that the torque value at the stable region was taken to calculate yield stress. Torque at zero rotational speed was obtained by extrapolating the torque values at various speeds to remove the effect of the rotational drag. As general verification, yield stress of feedstocks made of Tungsten carbide powder with wax-based binder was measured at different temperatures and various powder concentrations.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.107-107
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• 2010

Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas have played an important role of synthesizing the valuable chemical compound, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuels and chemical production. Current thermal processing techniques such as fast pyrolysis, slow pyrolysis, and gasification tend to generate products with a large slate of compounds. Lignocellulose feedstocks such as forest residues are promising for the production of bio-oil and synthesis gas. Pyrolysis and gasification was investigated using thermogravimetric analyzer (TGA) and bubbling fluidized bed gasification reactor to utilize forest woody biomass. Most of the materials decomposed between $320^{\circ}C$ and $380^{\circ}C$ at heating rates of $5{\sim}20^{\circ}C/min$ in thermogravimetric analysis. Bubbling fluidized bed reactor were use to study gasification characteristics, and the effects of reaction temperature, residence time and feedstocks on gas yields and selectivities were investigated. With increasing temperature from $750^{\circ}C$ to $850^{\circ}C$, the yield of char decreased, whereas the yield of gas increased. The gaseous products consisted of mostly CO, CO2, H2 and a small fraction of C1-C4 hydrocarbons.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.587-594
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• 2010

Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas has played an important role of synthesizing the valuable chemical compounds, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuel and chemicals. Current thermal processing techniques such as fast pyrolysis, slow pyrolysis, and gasification tend to generate products with a large slate of compounds. Lignocellulose feedstocks such as forest residues are promising for the production of bio-oil and synthesis gas. Pyrolysis and gasification was investigated using thermogravimetric analyzer (TGA) and bubbling fluidized bed gasification reactor to utilize forest woody biomass. Most of the materials decomposed between $320^{\circ}C$ and $380^{\circ}C$ at heating rates of $5{\sim}20^{\circ}C$/min in thermogravimetric analysis. Bubbling fluidized bed reactor was used to study gasification characteristics, and the effects of reaction temperature, residence time and feedstocks on gas yields and selectivities were investigated. With increasing temperature from $750^{\circ}C$ to $850^{\circ}C$, the yield of char decreased, whereas the yield of gas increased. The gaseous products consisted of mostly CO, $CO_2$, $H_2$ and a small fraction of $C_1-C_4$ hydrocarbons.

• Journal of the Korean Magnetics Society
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• v.8 no.2
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• pp.86-92
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• 1998

Homegeneous feedstock is necessary to make plastic magents with uniform magnetic properties, therefore the optrimized mixing route and the homogeneity evaluation method are demanded. In this paper, method of homogeneity evaluation and effect of homogeneity on the magnetic prperites were investigated using Sr-ferrite /EVA plastic magnets. The feedstocks with different homogeneity were prepared using batch mixer and single screw extruder. The homogeneities of feedstocks were tested by torgue sensor, capilary rheometer, and measurement of magnetic properties. Mixing torque measurement using torque sensor was an effective method to determine the critical powder loading, but it was nor suitable to suitable to determine the feedstock mixing quality. Particle alignment measurement of a plastic magent was very accurate to evaluate the homogeneity, but expensive equipments were required to make and measure the samples. Pressure measurement using capillary rheometer was a very effective and easy method with high accuracy. Homogeneous feedstock increased the particle alignment of plastic magnet. Remanet flux density and maximum energy product increased linearly and quadratically with increasing particle alignment, respectively.

• Environmental and Resource Economics Review
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• v.30 no.1
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• pp.49-77
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• 2021

This study uses a choice experiment approach to examine whether different types of feedstocks as well as other attributes such as the cost of bioethanol, bioethanol blending ratio, and government support policies affect consumers' biofuel preferences. We apply a standard conditional logit model, a mixed logit model (MLM), and individual coefficient estimation model (ICM) to estimate the parameters of the investigated attributes. The results show that people prefer domestic and non-food feedstock, along with tax exemption as a support policy. All the attributes show unobservable preference heterogeneity in the MLM and ICM. In particular, willingness to pay for attributes are higher in the genetically modified (GM) feedstock-unknown group than in the known one. We show the importance of using domestic and non-food feedstocks and managing GM feedstocks carefully to avoid consumer resistance when producing bioethanol in South Korea.