• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.988-993
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• 2012

Energy and cost analysis of the preprocessing for carbon capture and storage transportation such as supercritical compression and liquefaction is done using chemical simulation model. Direct compression to supercritical phase (process 1-1), liquefaction and pumping (process 1-2), carbon dioxide compression and expansion as a refrigerant itself (process 2), usage of other refrigerant with compression and expansion (process 3-1), with absorption chiller (process 3-2), cascade refrigeration (process 3-2) have been simulated and evaluated. The specific cost is about 4 to 7 $/ton.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.226-236
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• 2019

In this study, functional and emulsifying properties of oil extracted by supercritical carbon dioxide from balloonflower(Platycodon grandiflorum A. DC) seeds were investigated. The oil was lower in total polyphenol content(8 mg/100 g), but higher in ${\alpha}$-tocopherol(14.15 mg/100 g), ${\beta}$-sitosterol(116 mg/100 g) and stigmasterol(8 mg/100 g) contents than seeds. Based on DPPH radical scavenging activity, the oil($IC_{50}=1235.5{\mu}g/mL$) showed similar antioxidant activity to the seeds($IC_{50}=1138.2{\mu}g/mL$). At 1%(w/w) lecithin, O/W emulsion with balloonflower seeds oil had turbidity, microscopic image, mean particle size and emulsion stability similar to emulsion with soybean oil, but had lower turbidity and emulsion stability and larger mean particle size than emulsion with perilla seeds oil. Its surface tension was similar to perilla oil emulsion.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.98-99
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• 2005

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.140.2-140.2
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• 2007

• KSBB Journal
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• v.23 no.6
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• pp.494-498
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• 2008

We investigated the bioethanol production using wood biomass hydrolysate which obtained from the supercritical water (SCW) treatment. SCW-treated hydrolysate was used C-source of culture medium in shaking flask culture for bioethanol production. When the concentrated SCW-treated hydrolysate (SCW3) was used, yeast cell growth was slower compared with those in other SCW-treated hydrolysate (SCW1, SCW2). In addition, the bioethanol productions were 0.51 to 0.56 (%,w/v) when SCW1, SCW2, and SCW3 were used. Therefore, we removed the toxic phenolic compound in SCW-treated hydrolysate by pretreatments of activated charcoal and calcium hydroxide. Activated charcoal reduced more efficiently the phenolic compounds in SCW3 by 94.6%. Finally, when we pretreated SCW3 by activated charcoal and this was used for bioethanol production, 0.96 (%,w/v) bioethanol was produced and the ethanol yield based on reducing sugar reached 0.5.

• Clean Technology
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• v.13 no.4
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• pp.244-250
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• 2007

Sorption of C. I. Disperse Yellow 54 dye in poly(trimethylene terephthalate) (PTT) and poly (ethylene terephthalate) (PET) textile fibers were measured at various pressures, temperatures, and times in the presence of supercritical carbon dioxide and thereby the diffusivities of the dye in the fibers were calculated. The diffusivity of dye in the polymeric fibers was very low, only in the order of $10^{-12}\;cm^2/sec$, but increased with increasing temperature at constant pressure and with increasing pressure at constant temperature. The diffusivity in PTT fibers were about 1.5 to 3 times as large as that in PET fibers. As the fiber was very thin, the dye distribution in the fiber was almost uniform everywhere inside the fiber.

• Clean Technology
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• v.14 no.4
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• pp.248-255
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• 2008

The volume expansion of three ionic liquids (ILs) in the presence of supercritical carbon dioxide has been measured at pressures up to 32 MPa and at temperatures from 313.15 to 333.15 K in a high-pressure view cell. The imidazolium-derivative ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][$BF_4$]), and 1-octyl-3-methylimidazolium tetrafluoroborate ([omim][$BF_4$]) were employed in this research. The effects of pressure, temperature, nature of anion and cation as well as the water content on the volume expansion of ILs by absorbing $CO_2$ were investigated experimentally. The volume expansion was higher for the ILs with longer cationic alkyl group and for the ILs with lower anion polarity. The lower the water content, the lower the temperature, or the higher the pressure, the higher was the expansion of IL phase.

• Clean Technology
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• v.15 no.2
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• pp.69-74
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• 2009

A high-dose ion-implanted photoresist (HDIPR) was stripped off from the surface of a semiconductor wafer by using a mixture of supercritical carbon dioxide and a co-solvent. The additional ultrasonication improved the stripping efficiency remarkably and thus reduced the stripping time by supplying physical force to the substrate. We investigated the effect of co-solvents, co-solvent concentration, and stripping temperature and pressure on the stripping efficiency. The wafer surfaces before and after stripping were analyzed by scanning electron microscopy and by an energy dispersive X-ray spectrometer. The HDIPR could be stripped off completely in 3 min with 10%(w/w) acetone/sc$C0_2$ mixture at 27.6 MPa and 343 K.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.438-444
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• 1999

The natural full-fat rice bran is reported to contain 8.4 to 14.7 wt % Lipids, but the amount and composition of bran depend on the type of rice, quality of paddy, pretreatments to paddy such as parboiling, type of milling system employed, and the degree of polishing. These lipids are usually mixtures of several class fatty acids containing palmitic acid, linolenic acid, linoleic acid, oleic acid, stearic acid, tocopherol, squalene, etc. In this study the oil rich essential fatty acid (EFA) including squalene was extracted from the domestic brown rice bran using supercritical fluid extraction (SFE) and cosolvent induced SFE process, respectively. And the extracts were analyzed with GC-MSD. The extracted amount of rice bran oil was dependent upon the operating pressure and temperature, and the fatty acid composition of oil was varied with the reduced density (${\rho}_{\gamma}$) of supercritical carbon dioxide. About 70~80% of rice bran oil was extracted in 4hrs. The cosolvent induced SFE process shortened the total extraction time, extracted greater amount of oil than SFE process. Especially squalene which was not found in solvent extract phase was identified in SFE and cosolvent induced SFE process.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.53-59
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• 2005

In this study, the supercritical electroplating was investigated by forming macroemulsion of electroplating solution using surfactant in supercritical $CO_2$. The fluorinated analogous AOT surfactant, sodium salt of bis (2,2,3,3,4,4,5,5-octafluoro-1-pentanol) sulfosuccinate which has both '$CO_2$ philic' chains and 'hydrophilic' head group was used as a surfactant, and Ni plate and Cu plate were used as the anode and the cathode, respectively. Electroplating was carried out in the conventional method and the supercritical macroemulsion and both results were compared. The supercritical electroplating was carried out in various concentration of surfactant such as 2, 4, 7 wt%, the volume ratio of Ni-plating solution to $CO_2$ was varied in the range of 10-70 vol%, and propane was used as a supercritical fluid instead of $CO_2$. According to the experimental results, the plated surface of Ni on Cu plate performed in supercritical macroemulsion was better than that, in conventional state. In the image of Ni surface plated on Cu plate in supercritical state, there were fewer pin-holes and pits comparing with that in the conventional process. The current and conductivity was increased as the volume ratio of Ni-plating solution to $CO_2$ was increased and the current and the amount of Ni plated on Cu plate were decreased as the concentration of surfactant become higher. In addition, in case of the continuous phase, using $CO_2$ was more effective than using $CO_2$.