• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.365-370
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• 2012

In this study, Economic analysis of supercritical coal-fired power plant with $CO_2$ capture process was performed. For this purpose, chemical absorption method using amine solvent, which is commercially available and most suitable for existing thermal power plant, was studied. For the evaluation of the economic analysis of coal-fired power plant with post-combustion $CO_2$ capture process in Korea, energy penalty after $CO_2$ capture was calculated using the power equivalent factor suggested by Bolland et al. And the overnight cost of power plant (or cost of plant construction) and the operation cost reported by the IEA (International Energy Agency) were used. Based on chemical absorption method using a amine solvent and 3.31 GJ/$tonCO_2$ as a regeneration energy in the stripper, the net power efficiency was reduced from 41.0% (without $CO_2$ capture) to 31.6% (with $CO_2$ capture) and the levelized cost of electricity was increased from 45.5 USD/MWh (Reference case, without $CO_2$ capture) to 73.9 USD/MWh (With $CO_2$ capture) and the cost of $CO_2$ avoided was estimated as 41.3 USD/$tonCO_2$.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.848-854
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• 1998

To concentrate polyunsaturated fatty acids from anchovy oil by supercritical carbon dioxide $(SC-CO_2)$, effects of different adsorbents, cosolvents and extraction pressures on the extraction yield and fatty acid composition in the extract and the residue fractions were investigated. Anchovy oil mixed with silver nitrate-coated silica gel showed higher extraction yield and concentration of EPA and DHA in the residual fraction than that mixed with only silica gel at $60^{\circ}C/345{\;}bar$. Ethyl acetate was a promising cosolvent for concentrating polyunsaturated fatty acids in the residual fraction from anchovy oil mixed with silica gel. For the extraction pressures tested, 276 bar showed a maximum value in the extraction yield and concentration of EPA and DHA in the residue. Starting with anchovy oil containing 13.3% EPA and 16.2% DHA mixed with a silver nitrate-coated silica gel, the residue fraction containing 28.2% EPA and 38.3% DHA was obtained when ethyl acetate was used as a cosolvent with $SC-CO_2$ at $60^{\circ}C/276{\;}bar$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.205-210
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• 2012

For environmental reasons and because of our limited energy resources, high-efficiency power generation technology will be necessary in the future. Ultra-supercritical (USC) power generation technology is the key to managing the greenhouse gas problems and energy resource problems discussed in the Kyoto Protocol to the United Nations Framework Convention on Climate Change. Other countries and manufacturers are trying to build commercial power plants. In this paper, an efficient method of achieving near-zero emission operation of a high-efficiency fossil power plant using USC power generation is discussed. Development of USC power generation in Korea has been supported by the Korean government in two phases: Phase I was USC key technology development from 2002 to 2008, and Phase II is USC development and technology optimization from 2010 to 2017.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.19-23
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• 2003

The optimum extraction condition of pungent component from Zanthoxylum piperitum D.C pericarps by using supercritical fluid extraction(SFE) was investigated. The optimum condition of SFE was $300kg/cm^2$ of pressure, $60\;^{\circ}C$ of extraction temperature, 80% of $CO_2$ fluid, 20% of modifier(methanol) volume and 20 min of extraction time. The extraction efficiency between the classical solvent extraction method and SFE was studied. About 40% of extraction efficiency was improved when SFE was applied.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.50-50
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• 2004

• 한국전기화학회:학술대회논문집
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• 2003.07a
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• pp.177-181
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.239-240
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• 2005

• Journal of Soil and Groundwater Environment
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• v.21 no.2
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• pp.29-37
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• 2016

CO₂ injection well sealant is vulnerable to supercritical CO₂ (scCO₂) exposure. To develop an alternative to the conventional sealant system (class G cement/class F fly ash), the performance of slag cement (SPC) systems containing class F fly ash (FFA) or class C fly ash (CFA) was evaluated and compared with the conventional sealant under scCO₂ conditions. All sealant systems showed an immediate increase in compressive strength upon scCO₂ exposure and, at 37.6 MPa, SPC/CFA showed the highest compressive strength after 14 days, which was much higher than the 29.8 MPa of the conventional sealant system. Substantial decreases in porosity were observed in all sealant systems, which were partly responsible for the increase in strength. Carbonation reactions led to pH decreases in the tested sealants from 12.5 to 10~11.6. In particular, the greatest decrease in pH in slag cement/class C fly ash probably supported relatively sustainable alkali activation reactions and the integrity of cement hydrates in this system. XRD revealed the presence of CaCO₃ and a decrease in the content of cement hydrates in the tested sealants upon scCO₂ exposure. TGA demonstrated a greater increase of CaCO₃ and calcium-silicate-hydrate phases in SPC/CFA than in the conventional sealant upon scCO₂ exposure.

• Clean Technology
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• v.12 no.2
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• pp.62-66
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• 2006

Poly($\small{L}$-Lactide)(PLLA) was prepared by a ring-opening polymerization of $\small{L}$-Lactide with various polydimethylsiloxane(PDMS) based copolymers as a stabilizer in supercritical carbon dioxide($scCO_2$). The block copolymeric stabilizers were synthesized by group transfer polymerization (GTP) by using PDMS macroinitiator. PLLA was found to be produced with fairly low molecular weight distribution as confirmed by gel permeation chromatography(GPC) analysis. Scanning electron microscopy (SEM) results showed that sub-micron size Poly($\small{L}$-lactide)(PLLA) particles were formed by suspension polymerization.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.649-656
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• 2006

The proposed head-space supercritical fluid extraction (SFE) methodology as an alternative to an existing conventional procedure was explored for the determination of organochlorine compounds in aqueous matrix. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were utilized as target analytes. To enhance the recovery efficiency, the factors such as the $CO _2$ density, the extraction time, and the extraction mode were investigated. Furthermore, the analytical procedures and the results obtained were compared with those provided by the conventional method (the U.S. EPA method 8080). Under the optimized conditions, i.e., a combination of static with dynamic SFE mode at 2,000 psi and 40 ${^{\circ}C}$, the head-space SFE methodology gave equivalent or better to the conventional method in recovery efficiencies with clear advantages such as simple sample treatment and fast analysis time as well as reduced solvent and reagent consumption.