• Journal of the Korean Society for Precision Engineering
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• v.23 no.10
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• pp.36-43
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• 2006

• Clean Technology
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• v.13 no.1 s.36
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• pp.34-45
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• 2007

Phase behavior of the ternary systems of water-insoluble simvastatin drug, which is well known to be effective drugs for hypercholesterolemia therapy, in solvent mixtures of dichloromethane and supercritical carbon dioxide was investigated to present a guideline of establishing operating conditions in the particle formation of the drugs by a supercritical anti-solvent recrystallization process utilizing dichloromethane as a solvent and carbon dioxide as an anti-solvent. The solubilities of simvastatin in the mixtures of dichloromethane and carbon dioxide were determined as functions of temperature, pressure and solvent composition by measuring the cloud points of the ternary mixtures at various conditions using a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The solubility of the drug increased as the dichloromethane composition in solution and the system pressure increases at a fixed temperature. A lower solubility of the drug was obtained at a higher temperature. The second half of this work is focused on the particle formation of the simvastatin drug by a supercritical anti-solvent recrystallization process in a cylindrical high-pressure vessel equipped with an impeller. Microparticles of the simvastatin drug were prepared as functions of pressure (8 MPa to 12 MPa), temperature (303.15 K, 313,15 K), feed flow rate of carbon dioxide, and stirring speed (up to 3000 rpm), in order to observe the effect of those process parameters on the size and shape of the drug microparticles recrystallized.

• Proceedings of the Korean Reliability Society Conference
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• 2002.06a
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• pp.235-243
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• 2002

• 지반과기술
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• v.4 no.3
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• pp.105-109
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• 2007

• The monthly packaging world
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• s.346
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• pp.80-85
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• 2022

• Journal of the Korean Chemical Society
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• v.47 no.3
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• pp.283-291
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• 2003

The purpose of this research was to analyze and improve the experiment, observing the color change under compression on the equilibrium of $2NO_2\;{\rightleftarrow}\;N_2O_4$ system, described in high school and general chemistry textbooks. Chemistry textbooks described that the reddish brown color got lighter on the compression of $2NO_2\;{\rightleftarrow}\;N_2O_4$ system. This misinterpretation was due to no consideration of $NO_2$ concentration increase by the volume decrease. In order to propose a correct interpretation, the changes of color and temperature on compression were quantitatively measured and compared with theoretical studies. In addition, an improved experiment, excluding the effect of $NO_2$ concentration increase, was proposed to observe only the color change of the net equilibrium shift.

• Clean Technology
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• v.13 no.1 s.36
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• pp.46-53
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• 2007

We depolymerized PET in supercritical methanol and observed the yield of DMT at various reaction conditions. At subcritical state below $240^{\circ}C$, the yield of DMT was very low, about only 50%. It increased dramatically to 80% at supercritical state above $260^{\circ}C$, thereafter the increasing rate was reduced significantly. Similarly, at subcritical state of 6.89 MPa, the DMT yield was only 50%, but it increased abruptly to 85% at supercritical state of 10.34 MPa, yielding no further increase above the pressure. Within 10 minutes after the beginning of the reaction, the DMT yield reached 80%, indicating that the significant portion of the reaction has proceeded, and then, the yield increased slowly. The methanol/PET ratio of 8 showed the maximum DMT yield. We found the optimum depolymerization condition fur PET methanolysis is temperature $300^{\circ}C$, pressure 10.34 MPa, reaction time 40 minutes, and methanol/PET ratio of 8.

• KSBB Journal
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• v.18 no.4
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• pp.301-305
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• 2003

The study of pancreatin extraction was investigated by supercritical fluid process. Using supercritical carbon dioxide extraction with entrainer the purification of pancreatin was possible to remove lipids from Hog pancreas. To observe the optimum conditions different experimental variables were changed as pressure, temperature, flow rate of solvent and 0.25 mm of sample size were evaluated for effective removal of lipids. Ethanol and n-hexane were used as an entrainer with 5 mL/min. Increasing pressure at constant temperature the efficiency of the lipid removal in Hog pancreas was improved and the protein was concentrated without denaturalization, compared that of the control Hog pancreas. The most efficient conditions of lipid elimination were 17 MPa of pressure and 35$^{\circ}C$ of temperature and 0.25 mm of sample size.

• KSBB Journal
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• v.22 no.5
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• pp.336-340
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• 2007

Supercritical carbon dioxide was used to remove coffee odors. The odor removal efficiency was tested with coffee drink prepared by the espresso extraction method. Five typical odors in coffee were analyzed with GC and these odors in deodorized coffee were compared to those in control. Supercritical carbon dioxide extraction conditions were optimized as 350 bar and 70$^{\circ}C$ because the solvating power of supercritical fluid is depend on the density which is determined by temperature and pressure. A modified head space method was applied to collect coffee odors in coffee drink prepared by the espresso extraction method. Odors generated in coffee drink made with deodorized coffee powder were reduced by 73% in total mass of typical five coffee odors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.629-635
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• 1993

Full fat sardine oil is readily extracted with supercritical carbon dioxide($SC-CO_2$) at pressure of 5,000~8,000 psig. and temperature of 50~$80^{\circ}C$. Under these conditions $SC-CO_2$ has the density of fluid and diffusivity of gas. Therefore, equilibrium solubility is readily achieved in a column batch extractor which permits high gas flow rates. The results showed that extraction was higher at the pressure of 6,000 psig. and $60^{\circ}C$. Fish oil extracted with $SC-CO_2$ is lighter in color, smells less and contains less iron and phosphorus than hexane-extracted crude oil from the same sardine oil. Eicosapentaenoic acid($C_{20-5}$) in sardine oil was fractionated at 90.5% by the $SC-CO_2$ extractor with heat exchange.