• Bulletin of Food Technology
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• v.9 no.2
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• pp.173-180
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• 1996

필자들은 96년 4월 28일부터 5월 6일까지 8박 9일간 미국 Indiana주의 Indianapolis에서 열린 미국유화학회에 참석하여 "초임계유체로 추출한 들기름의 특성과 산화안전성"에 관한 논문을 발표하고, 학회 개최지에서 약 3시간 정도 떨어진 Peoria에 위치한 USDA를 방문하여 유지 관련분야의 최근동향 및 연구과제를 탐색하였다. 또한 시카코에서 5월 5일부터 5월 8일까지 열리는 Food Marketing institute에 참석하여 식품에 관련된 신제품의 개발 현황과 수퍼마켓의 운영방법에 대한 것을 살펴보았다.

• Journal of the Korean Chemical Society
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• v.48 no.3
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• pp.243-248
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• 2004

Brake theory of viscosity, which can sucessfully calculate the viscosity of real gases, dense gases and liquids, is extended to the binary gas mixture. Adjustable parameters are not involved, but the calculated results are good agreements with the experimental values at high pressure as well as low pressure. Corresponding state equation for viscosity can be obtained by using the Redlich-Kwong equation, so that we hope this equation may be useful for the supercritical fluid in engineering applications at high pressure around the critcal point.

• KSBB Journal
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• v.14 no.5
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• pp.633-637
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• 1999

Supercritical fluid of carbon dioxide was used to investigate the effects of its temperature and density on the distribuion coefficients of fatty-acid esters composing fish oil. The distribution coefficient of fatty acid ester was greatly different from each other according to the temperature and density of the supercritical fluid. The possibility of separation of a certain fatty acid from the mixture of fatty acids was tested. The density of the supercritical fluid showing the great differences ofthe distribution coefficients among the fatty acid esters ranged from 0.3 g/mL to 0.4 g/mL. The retrograde condensation took place at high densities of the supercritical fluid.

• Elastomers and Composites
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• v.34 no.3
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• pp.239-246
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• 1999

Side wall samples from a used automotive tire were subjected to subcritical and supercritical decomposition and extraction with three solvents, water, 28% ammonia solution and ammonia. For 6mm cube samples the rate of supercritical extraction with water followed a first-order kinetics with an activation energy of 140 kJ/mol. Solvent power of 28% ammonia so lotion at supercritical condition was found to be higher than supercritical water at initial extraction as pressure decreased. These phenomena were considered to be an effect of ammonia involved in water.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.578-584
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• 2003

Polychlorinated biphenyls (PCBs) known as environmental contaminants in soil were analyzed by the soil pollution standard process test and the static supercritical $CO_2$ extraction mode. It was shown that the percent average recoveries of PCBs by the soil pollution standard process test were ranged in 25-35% and the corresponding standard deviations were above 10%. In contrast, the percent average recoveries of PCBs by the static supercritical $CO_2$ extraction mode were 2-2.5 times higher and standard deviations were within 7%. These results indicate that static supercritical $CO_2$ extraction mode may be a useful alternative to sample pretreatment certified by the soil pollution standard process test. The increasing supercritical $CO_2$ pressure from 1130 psi to 1996 psi at $40^{\circ}C$ enhanced the recovery of all PCB congeners from soil. However, at same Tc and Pc, the equilibrium time (5 versus 60 minutes) had no effect on the recovery of each PCB congener. Finally, similar PCB recoveries were obtained under the same extraction condition, regardless of the molecular weight and structure (coplanar versus non-coplanar) of PCB congeners.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.705-708
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• 2001

Enzymatic synthesis and purification of sugar esters using supercritical $CO_2$ were investigated. The observed yield of suagr ester produced by transesterification of methyl glucoside and oleic acid using a lipase(Novozym 435) was 67% at 24 hours of reaction in the supercritical $CO_2$. The solubility of the fatty acids in the supercritical $CO_2$ was measured to find the conditions of supercritical separation of the fatty acids from the reaction mixture. The solubility of capric and oleic acid was 5 ${\times}$ $10^{-4}$, 1.7 ${\times}$ $10^{-4}$ mol/mol $CO_2$, respectively, varying at $35{\sim}50^{\circ}C$ and 80${\sim}$120 atm.

• KSBB Journal
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• v.14 no.1
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• pp.109-113
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• 1999

Supercritical $CO_2$ chromatography was applied for purification of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. Various supercritical $CO_2$ pressures were tested to find out the pressure effects on solubility and selectivity of low fatty acids in the silver nitrate column. The solubility of low fatty acids was increased as the supercntical $CO_2$ Pressure increased. However, the selectiviy between low fatty acids and EPA waw decreased. Stepwise density gradient method was applied to increase the purification efficiency of EPA. Low fatty acids were easily separated at the early elution steps with low $CO_2$ densities. Successive fractions containing 92.1~97.8% of EPA were collected. The average concentration of three purified fractions was 95.6% with the recovery rate of 30%.

• Journal of the Korean Ceramic Society
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• v.40 no.12
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• pp.1220-1223
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• 2003

TiO$_2$ and TiO$_2$-CdS which were expected to be highly activated photocatalysts with semiconductor properties, were prepared using supercritical fluid method. The powders prepared by supercritical fluid were agglomerate foam in 2-3 ${\mu}{\textrm}{m}$ size and the primary particles of 20 nm were arranged in the powders. The powders which were prepared by supercritical fluid method were anatase phase without any heat treatment.

• Clean Technology
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• v.14 no.3
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• pp.153-159
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• 2008

The solubility of triclosan, an anti-acne agent was measured in supercritical carbon dioxide ($scCO_2$) with a variable volume view cell at 313.15, 323.15, and 333.15 K and at pressures between 10 and 40 MPa. We successfully correlated triclosan solubility in $scCO_2$ using the quasi-chemical nonrandom lattice fluid (QLF) equation of state. Triclosan was micronized using the rapid expansion of supercritical solutions (RESS) process. The effects of temperature and pressure on particle size were investigated using phase behavior data and correlated results from the QLF model.

• Clean Technology
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• v.18 no.2
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• pp.155-161
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• 2012

The purpose of this study is to remove paraffin wax binder effectively from powder injection molded part using supercritical fluids in powder injection molding process. For a thin powder injection molded part about 1-2 mm thickness, paraffin wax binder can be removed rapidly without any defect by traditional supercritical extraction process which has fixed high temperature and pressure condition. But, for a thick powder injection molded part, there are limitations in removing paraffin wax binder by the fixed high process condition because crack occurs at the beginning step. Therefore, here we studied variable condition debinding process that starts with mild process condition at the beginning step and then increase the process conditions simultaneously at each step. To find out the initial process condition that has the highest extraction yield without any defect for each sample thickness, we investigated various supercritical debinding conditions using 1-4 mm thickness ceramic injection molded sample. By using the variable condition debinding process that starts with the initial process condition at the first step and then increasing process conditions simultaneously at each step (temperature from 333.15 to 343.15 K, pressure from 12 to 27 MPa, and $CO_2$ flow rate from 1.5 to 10 L/min), over 95% of paraffin wax binder was removed from the 4 mm thick (10 mm diameter) ceramic injection molded disk samples within 5 hours.