• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.516-519
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• 2000

Generally pancreas consist of lipid, water and protein, digestion enzyme complex (pro-tease, lipase, amylase). The sample used in this work was frozen dry and treated by a semi-batch flow type. In order to develop a supercritical fluid extraction process to rem-ove lipid from the pancreas, experiments were conducted at various operating conditions(pressure range $1500{\sim}2800psi$, temperature range $25{\sim}40^{cdot}C$, particle size$(0.25{\sim}1.0mm$, flow rate $20{\sim}80m{\ell}/min)$. Also cholesterol in the pancreas was removed. The highest extraction efficiency was 2500psi, $35^{\cdot}C$, 0.25mm of pancreas size. The enzyme activity of the pancreas produced from this work showed high value compared with imported pancreas.

• Clean Technology
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• v.9 no.4
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• pp.197-206
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• 2003

We performed removal of aromatic compounds, benzene and toluene, from soil and zeolite using supercritical carbon dioxide. Extraction was performed at $50^{\circ}C$ and 27.7 MPa with changing the extent of pollutant concentration and the results were compared and analyzed. Experiments were carried out using flow method and high pressure extractor of 1.27 cm in diameter and 25cm in length was used. The pollutants were sampled every ten minutes and their concentrations were analyzed with GC/FID. As a result, highly contaminated sample followed solubility/elution model and slightly contaminated sample followed desorption/kinetics model. At the same condition benzene was extracted faster than toluene. In the case of zeolite, more time is required to extract pollutants than soil. This phenomena was due to high adsorption capacity of zeolite. In the case of highly contaminated soil, we could correlate experimental data using simple Brady's fixed bed extractor model. But in the case of slightly contaminated soil, that was governed with desorption/kinetics model, there was some errors.

• Clean Technology
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• v.18 no.2
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• pp.191-199
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• 2012

In order to reduce or remove off-flavor and volatile organic compounds (VOCs) from Laminaria japonica effectively, continuous treatment process by supercritical carbon dioxide (SC-$CO_2$) was applied. After freeze-drying, Laminaria japonica powdered with $710{\mu}m$ was used. Experiments were carried out at temperature range from 35 to $55^{\circ}C$, and pressure range from 10 to 25 MPa for evaluation of SC-$CO_2$ treatment effect. Flow rate of carbon dioxide used in this reseach was constantly fixed at 26.81 g/min. Before and after treatment of SC-$CO_2$, off-flavor and VOCs from Laminaria japonica were analyzed by gas chromatography-mass spectrometry detector (GC-MSD). Total 47 VOCs emitted from Laminaria japonica were identified before treatment of SC-$CO_2$, major components of seaweed smell (ordor) in Laminaria japonica were identified as alcohols, aldehydes, ester and acids, ketone, halogenated compounds and hydrocarbon. Off-flavor and VOCs in all experimental conditions was reduced or removed after SC-$CO_2$ treatment. Among the experimental conditions, the highest removal yield was at 25 MPa and $55^{\circ}C$.

• Clean Technology
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• v.17 no.3
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• pp.266-272
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• 2011

Anchovy oil was extracted using supercritical carbon dioxide ($SCO_2$) and organic solvents. Extraction was carried out at temperature range from 40 to $60^{\circ}C$, and pressure range from 15 to 25 MPa. The flow rate of $CO_2$ (22 $gmin^{-1}$) was constant entire the extraction period of 1.5 h. The fatty acid composition of anchovy oil was analyzed by gas chromatography (GC). The main fatty acids of anchovy oil were myristic acid, palmitic acid, stearic acid, palmitoleic acid, EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid). In addition, the oil obtained by $SCO_2$ extraction contained a higher percentage of polyunsaturated fatty acids especially EPA and DHA comparing to the organic solvent extracted oil. The oxidative stability of oils extracted from Anchovy by $SCO_2$ extraction was compared to those extracted by organic solvents. Results showed that the storage periods of oils obtained by $SCO_2$ extraction were longer than those of organic solvents extraction.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.427-432
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• 2004

The purpose of this study is to investigate the feasibility of a cosolvent-modified supercritical $CO_2\;(scCO_2)$ extraction technique for the production of licorice extracts with high levels of glabridin. The effects of various parameters such as the type and amount of modifiers, extraction temperature ($40{\sim}80^{\circ}C$) and pressure ($10{\sim}50.0\;MPa$) on the extraction efficiency were examined at a fixed flow rate of 1 mL/min. The organic solvent extraction with pure methanol was also conducted for a quantitative comparison with the $scCO_2$ extraction. The recovery of glabridin from licorice was found to be extremely small for pure $scCO_2$. However, the addition of modifiers such as ethanol and acetone to $scCO_2$ resulted in a significant improvement in the recovery of glabridin. The recovery of glabridin was observed to increase with pressure at a constant temperature. Furthermore, the purity of the glabridin obtained from the $scCO_2$ extraction was higher compared with the organic solvent extraction.

• KSBB Journal
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• v.21 no.3
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• pp.194-198
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• 2006

Dried raw Ascidians(Halocynthia roretzi) shells harvested from fish farms in southern coast area in Korea were used to extract ${\beta}$-carotene using supercritical carbon dioxide($SCO_2$) and with ethanol as a co-solvent at the range of temperatures and pressures, from 25 to $65^{\circ}C$ and 100 to 350 bar respectively. The size of the dried Ascidians shells was around $850{\mu}m$. The system used this study was a semi-batch flow type high pressure unit. The efficiency of ${\beta}$-carotene extraction using $SCO_2$ with and without co-solvent, ethanol, influenced to pressure and temperature changes. The highest solubility of ${\beta}$-carotene in $SCO_2$ was 1.35 mg/g for ${\beta}$-carotene at $35^{\circ}C$ and 350 bar. With addition of 2(v/v%) ethanol the recovery of ${\beta}$-carotene was 93%. As a result of using n-hexane and methanol for rinse, at $35^{\circ}C$ and 350 bar the amount of ${\beta}$-carotene by methanol rinse was 5 times higher than that of n-hexane rinse.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.2
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• pp.156-162
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• 2008

The condensation pressure drop for R-22 and R-410A flowing in a small diameter tube was investigated. The test section is a counterflow heat exchanger with refrigerant flowing in the inner tube and coolant flowing in the annulus. The test section consists of 1220 mm length with horizontal copper tube of 3.38 mm outer diameter and 1.77 mm inner diameter. The refrigerant mass fluxes ranged from 450 to $1050\;kg/m^2{\cdot}s$ and the average inlet and outlet qualities were 0.05 and 0.95, respectively. The main experimental results were summarized as follows : In the case of two-phase flow, the pressure drop increases with increasing mass flux and decreasing quality. The pressure drop of R-22 is slightly higher than that of R-410A for the same mass flux. Most of correlations proposed in the large diameter tube showed enormous deviations with experimental data.

• Water for future
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• v.20 no.4
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• pp.285-294
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• 1987

The floodwave analysis for unsteady supercritical flow is performed. The numerical model. based on dynamic wave equation is presented by introducing the general Preissmann scheme and fore-sweep algorithm.The model is applied to Buffalo-Creek floods for proving its validity, and the simulation results have good agreements with those computed by DAMBRK and the observed data. It is also applied to Hyogi dam-break. The outflow hydrograph is derived based on the observed data and the analysis for the floodwave propagation is investigated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.204-207
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• 2003

The present paper reports high-fidelity simulation of direct initiation processes of cylindrical detonation waves by concentrated energy deposition. The goal is to understand the underpinning mechanisms in failed or successful detonation initiation processes. We employed the Space-Time CESE method to solve the reacting flow equations, including realistic finite-rate chemistry model of the nine species and twenty-four reactions for H$_2$-O$_2$-Ar mixtures. Detailed results of sub-critical, critical. and supercritical initiation process are reported.

• 연구논문집
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• s.30
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• pp.15-23
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• 2000

In this study, develop the thermal pump using water evaporation and condensation. Vapor from heating room moves up to pumping room and press the water of pumping room. Consequently water is pumped out to water tank. Then hot vapor direct contact with cold water in condensing room after pumping process. At this time, pressure of condensing room is down to-5kPa and suck in water of tank. This pump executes self ping and good durability because of no mechanical moving parts. Thermal pump is pumped cyclic so that, this pump is not used single. Therefore thermal pump of hot water boiler used to multi-stage for stable pumping rate. As the result of performance test, the developed thermal pump proves pumping action of water evaporation/condensation. And total volume flow rate is 500liter during one hour. If three thermal pump is installed parallel, this pump can use to the hot water boiler in the 300,000kcal/h class.