• Title/Summary/Keyword: 초임계유체

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Regeneration Characteristics of Adsorbent Loaded with VOCs using Supercritical Carbon Dioxide (휘발성 유기용제가 흡착된 흡착제의 초임계 이산화탄소를 이용한 재생특성)

  • Lee, Seung Bum;Seong, Dae Hyung;Hong, In Kwon
    • Applied Chemistry for Engineering
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    • v.8 no.5
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    • pp.737-741
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    • 1997
  • The typical removal method of volatile organic compounds is adsorption process. In this study, granular activated carbon and activated carbon fiber were used as adsorbents, and the adsorption behavior for the two types of adsorbent was compared. And they were regenerated by supercritical carbon dioxide extraction at a constant temperature, 318.15 K, and 2000, 2500, 3000 psi respectively. The desorption percentage of initial adsorbates and iodine values were increased with pressure of supercritical carbon dioxide. The regeneration time was 70 and 60 minutes in adsorbents loaded with methyl ethyl ketone(MEK) and benzene, respectively. The desorption percentages were 64.0% for granular activated carbon and 55.3% for activated carbon fiber loaded with MEK, and 59.1% for granular activated carbon and 45.2% for activated carbon fiber loaded with benzene. The exit concentration could be evaluated by Tan and Liou model. Therefore, the granular activated carbon and the activated carbon fiber could be regenerated by supercritical fluid extraction process.

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Extraction Efficiencies of Organochlorine Pesticides Spiked in Fish Tissues by Supercritical Carbon Dioxide (초임계이산화탄소에 의한 어류조직 중 유기염소계 농약의 추출수율)

  • Lim, Sang-Bin;Jwa, Mi-Kyung;Kang, Soon-Bae
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.475-481
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    • 1996
  • A simple, fast, inexpensive method hal been developed to extract organochlorine pesticide spiked in fish tissues by supercritical carbon dioxide. Following static supercritical fluid extraction (SFE), pesticides are collected by rapidly depressurizing the carbon dioxide effluent through a 0.79 mm i.d. metering valve into a capped screw-top tube. Percent recovers of standard organochlorine pesticides mixture (SOPM) increased with the decrease of the extraction temperature at 103 bar. Maximum average percent recovery of SOPM was 98% at $40^{\circ}C/172\;bar$ Average recoveries of SOPM spiked in Pacific cod, flatfish and common squid were 85,74,and 83% respectively at $40^{\circ}C/172\;bar$ Application of supercritical carbon dioxide ectraction offers and attractive alternative to the use of organic solvents for extraction of organochlorine pesticides from fish tissues.

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Preparation of Self-humidifying Pt/Nafion Membranes using Supercritical $CO_2$ for PEMFCs (초임계유체를 이용한 PEMFC용 자가 가습 백금/나피온 막의 제조)

  • Byun, Jung-Yeon;Kim, Hyo-Won;Sung, Joon-Yong;Kim, Hwa-Yong
    • Clean Technology
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    • v.13 no.2
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    • pp.99-103
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    • 2007
  • Pt/Nafion self-humidifying membranes for Polymer Electrolyte Membrane Fuel Cell (PEMFC) were synthesized via a supercritical-impregnation method. The Nafion 112 membranes were impregnated with Pt(II) acetylacetonate from a supercritical carbon dioxide ($scCO_2$) solution at $80^{\circ}C$ and 19.8 MPa. After the impregnation, the Pt-impregnated Nafion membrane was converted Pt deposited Nafion(Pt/Nafion) membrane by reducing agent, sodium borohydride ($NaBH_4$) under $50^{\circ}C$ and 2 hours. The prepared Pt/Nafion membranes were investigated by SEM, EDS and EPMA. The performance of the Pt/Nafion membranes was examined in PEMFC as a self-humidifying membrane. The cell performance of the Pt/Nafion membrane at $65^{\circ}C$ is better than that of Nafion 112.

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Catalytic Oxidation Conversion Characteristics of VOCs in Supercritical Fluid Media (초임계유체 반응매개상에서 VOCs의 촉매산화 전환특성)

  • 이승범;홍인권;이재동
    • Journal of environmental and Sanitary engineering
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    • v.16 no.4
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    • pp.69-76
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    • 2001
  • The catalytic oxidation of volatile organic compounds (VOCs), which were benzene and toluene, was studied in the supercritical carbon dioxide($SC-CO_2$) media. In $SC-CO_2$ media, the deep oxidation conversion of VOCs was increased with the temperature and pressure. The deep oxidation conversion in SC -$CO_2$ media is better than that in air media at same pressure condition. This can be explained by the solubility of VOCs in $SC-CO_2$. The many intermediates produced by the partial oxidation of VOCs were detected from off-line samples. The intermediates were Identified as benzene, toluene, benzaldehyde, phenol, naphthalene, 1,1`-biphenyl, benzoic acid, 3-methylphenol, 1,1'-(1,2-ethanediyl)bis- benzene, 1,1'-(1,2-ethene- diyl)bis-benzene, anthracene, and so on. The amount of intermediates was decreased as the molar radio of oxygen to carbon dioxide was decreased. When the molar ratio of oxygen to carbon dioxide was 1 : 16, the deep conversion was kept constant. Thus, the catalytic oxidation process in $SC-CO_2$ media can be combined on-line with supercritical fluid extraction of environmental matrices and supercritical regeneration of used adsorbent. Thus, the nontoxic $SC-CO_2$ media process was suggested as the new VOCs control technology.

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Debinding Process Using Supercritical Fluids in Metal Powder Injection Molding (분말사출성형에서 초임계유체를 이용한 탈지공정)

  • 김용호;임종성;이윤우;박종구
    • Journal of Powder Materials
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    • v.10 no.1
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    • pp.6-14
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    • 2003
  • The purpose of the present study is to investigate the method decreasing debinding time as well as lowering operation condition than pure supercritical $CO_2$ debinding by using cosolvent or binary mixture of propane + $CO_2$. First method is to add cosolvent, such as n-hexane, DCM, methanol, 1-butanol, in supercritical $CO_2$. In case of adding cosolvent, we were found the addition of non-polar cosolvent (n-hexane) improves dramatically the binder removal rate (more than 2 times) compared with pure supercritical $CO_2$ debinding, second method is to use mixture of supercritical propane + $CO_2$, as solvent. In case of using mixture of supercritical propane + $CO_2$, the rate of debinding speeded up with increasing of pressure and concentration of propane at 348.15 K. It was found that addition of cosolvent (e.g., n-hexane, DCM) and binary mixture propane + $CO_2$ for supercritical solvent remarkably improved binder removal rate for the paraffin wax-based binder system, in comparison with using pure supercritical $CO_2$.

An Equation of State to Meet the Boundary Conditions between Critical Point and Inversion Points (임계온도와 반전점들 사이의 경계조건에서 구한 기체의 상태방정식)

  • Seung-Hee Kim;Wonsoo Kim;Tong-Seek Chair
    • Journal of the Korean Chemical Society
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    • v.35 no.5
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    • pp.487-492
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    • 1991
  • $[P+a(b/v)^n]$ = RT / (V - b) Above equation of state had been derived from Roulette theory. Three parameters-a, b, n are estimated from the critical point and the inversion temperature. When it is applied to 52 materials and to the regions of high density such as dense gas and supercritical gas, the results are good.

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Quality Characteristics of Ginseng Seed Oil Obtained by Different Extraction Methods (추출방법에 따른 인삼씨유의 품질특성)

  • Kim, Ji-Eun;Lee, Seul;Yoo, Kyung-Mi;Lee, Kyoung-Hae;Kim, Kyung-Tack;Lee, Myung-Hee;Hwang, In-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.3
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    • pp.439-445
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    • 2014
  • This study aimed to determine the quality characteristics of ginseng seed oil as well as evaluate the efficacy of ginseng seed oil as a food resource. Ginseng seed oil was obtained by different extraction methods; from solvent extraction oil, supercritical fluid extraction oil, and screw pressed extraction oil. Total unsaturated fatty acids were present at 97.72~97.92%. Oleic acid (80.13~81.16%) was the highest, followed by linoleic acid (14.98~15.69%). The total phenol content (mg gallic acid equivalent/100 g oil) was higher in screw pressed extraction oil ($56.32{\pm}1.47$) compared to others. ${\gamma}$-Tocopherol was only present in ginseng seed oil and screw pressed extraction oil showed the highest levels of ${\gamma}$-tocopherol ($5.95{\pm}0.25$ mg/100g oil) among the tested samples. Screw pressed extraction oil showed the greatest oxidative stability with an induction time of 16.58 hours. Acid values and peroxide values of ginseng seed oil increased with increasing storage period. The total phenol and ${\gamma}$-tocopherol contents were higher in screw pressed extraction oil than in other ginseng seed oils, which suggests that screw pressed extraction oil has the greatest oxidative stability.

Extraction of Taxol and Baccatin III from Needles of Taxus Cuspidata by Using Supercritical Carbon Dioxide with Cosolvents (초임계 이산화탄소와 보조용매를 이용한 주목잎에서의 Taxol과 Baccatin III의 추출)

  • 신혜원;전문균이훈
    • KSBB Journal
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    • v.11 no.1
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    • pp.100-106
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    • 1996
  • The extraction of taxol and baccatin III from the ground needles of Taxus cuspidata were carried out by using supercritical carbon dioxide with and without cosolvents such as ethylacetate and methanol at 300 bar and 313K. Taxol is a promising anticancer agent and baccatin III is a precursor of semisysthesis of taxol. The taxol and baccatin III contents in the extracts were determined by a HPLC. The highest yields of taxol and baccatin III could be obtained by the supercritical extraction with 3wt% methanol and ethylacetate, respectively, as cosolvents. It was also found that the selectivity of taxol and baccatin III were 0.117 and 1.245wt%, respectively, with 0.7wt% ethylacetate, which demonstrated that the selectivity of taxol and baccatin III were increased about 1.8 and 19 times than those of conventional organic solvent extraction.

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Effects of Particle Size and High Pressure Process on the Extraction Yield of Oil Compounds from Soybean Powder Using Hexane and Supercritical Fluid (입자 크기와 초고압 처리에 따른 유기용매와 초임계 유체 추출법에서의 대두유 추출수율의 변화)

  • Yoon, Won-Byong
    • Food Engineering Progress
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    • v.15 no.3
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    • pp.203-208
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    • 2011
  • Effects of particle size and high pressure processing on the extraction rate of oil compounds from soybean powder were evaluated by Soxhlet method using hexane and supercritical fluid extraction (SFE) using $CO_{2}$. SFE was carried out at 4,000 psi and $50^{\circ}C$ for 4 hr. The mean particle sizes were varied from 26.7 to 862.0 ${\mu}m$ by controlling milling time. Saturation solubility increased as the particle size decreased. At large particle size, high pressure processing (HPP) showed higher extraction yield in both hexane extraction and SFE, but, as the particle size decreased, the HPP was irrelevant to the extraction yield in SFE. The higher extraction rate obtained from the smaller particle size. The scanning electronic microscopy of soybean powder treated by HPP showed pores on the surface of the particle. The higher extraction rate and yield from HPP treatment might be due to the less internal resistance of transferring the solvent and miscellar in the solid matrix by collapsing of tissues.

Collagen Extraction Using Supercritical CO2 from Animal-Derived Waste Tissue (동물 유래 폐지방으로부터 초임계 CO2를 이용한 콜라겐 추출)

  • No, Seong-Rae;Shin, Yong-Woo;You, Seong-sik
    • Korean Chemical Engineering Research
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    • v.60 no.3
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    • pp.386-391
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    • 2022
  • This study is about a technique for obtaining collagen by extracting fat by treating collagen-containing liposuction effluent in the presence of supercritical fluid. Using a supercritical solvent, a collagen extract could be obtained from animal-derived fat in a short time (about 6 hours), and about 2-3% of collagen by mass compared to the raw material could be obtained. The presence of collagen in the extract obtained by supercritical extraction was confirmed by SDS-PAGE, and it was confirmed that it was type 1 collagen having a relatively large molecular weight. In addition, the growth factors of IGF-1, bFGF, VEGF and NGF were analyzed to find out which growth factors were present in the collagen obtained by supercritical extraction, and it was found that these growth factors were contained in the extract. There was no significant difference in DNA content per mg of sample before and after supercritical treatment. Further in-depth studies are likely to be needed on decellularization technology using the supercritical process. In conclusion, the extracellular matrix obtained through the solvent extraction process using a supercritical fluid contains growth factors above a certain amount even after decellularization and removal of fat, so that it was found that not only biocompatibility is greatly increased, but also tissue regeneration can be rapidly induced.