• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.75-82
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• 2016

The technology of fast pyrolysis is regarded as a promising route to convert lignocellulose biomass into bio-oil which can be upgraded to transportable fuels and high quality chemical products. Despite these promises, commercialization of bio-oil for fuels and chemicals production is limited due to its notoriously undesirable characteristics, such as high and changing viscosity, high water and oxygen contents, low heating value and high acidity. Therefore, in this study quality improvement of bio-oil through vaccum distillation had been targeted. A 600 g of cork oak(Quercus variabilis) which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 1.64 seconds at $465^{\circ}C$ and temperature of vaccum distillation(100hPa) was designed to control, $40^{\circ}C$, 50, 60, 70, and 80 for 30min. Bio-oil, biochar, and gas of pyrolytic product were produced to 62.6, 18.0 and 19.3 wt%, respectively. The water content, viscosity, HHV(Higher Heating Value) and pH of bio-oil were measured to 0.9~26.1 wt%, 4.2~11.0 cSt 3,893~5,230 kcal/kg and 2.6~3.0, respectively. Despite these quality improvement, production was still limited due to its notoriously undesirable characteristics, therefore continous quality improvement will be needed in order to use practical fuel of bio-oil.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.1
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• pp.5-13
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• 2022

Sunbigi tree(Vitex rotundifolia L.f.), which grows wild in the southern part of Korea and along the coast of the West Sea, has a lot of useful value in terms of resource utilization. Since ancient times, it has been used as folk medicine or herbal medicine in the private sector. Although the leaves and stems have a strong scent, the fruit also has a strong scent, so there are some studies on extracting essential oil from the fruit of Sunbigi tree and analyzing the ingredients, but there are few studies on the fragrance component by extracting hydrosol. The reason is that the fruits are hard and it is difficult to identify the active ingredients contained in the general extraction method. Therefore, in this study, the results of analyzing the components contained in the fragrance of hydrosol obtained by extracting hard fruits at high temperature by different extraction methods are as follows. 1. The extraction condition with the highest flavonoid content was 30.57 mg/g with ethanol, followed by hot water extract at 18.26 mg/g and water extract at 9.69 mg/g with the lowest. 2. As a result of distillation extraction from the fruit of Sunbigi tree, the fragrance of hydrosol is 3-Methyl-2-butenoic acid, cyclobutyl ester, Eucalyptol, L-alpha-Terpineol, 1H-Cycloprop[e]azulen-7-ol, decahydro-1 ,1,7-trimethyl-4-methylene-, [1ar-(1a.alpha.,4a.alpha.,7.beta.,7a.beta.,7b.alpha.)] were found to be many.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.179-185
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• 1996

Extraction yields of thiosulfinates from garlic were studied by using gas-in-liquis-dispersion(GLD) system to maxmize the thiosulfinate extraction. Extracted thiosulfinates were spectrophotometically quantified using synthesized dially1 thiosulfinate. The conditions for maximum extraction were optimized by response surface methodology. The volatile components extracted by various methods, such as hexane extraction, simultaneous steam distillation and GLD system, were compared by using gas chromatography. The results indicated that the thiosulfinate yield was increased by incresaing temperature and nitrogen gas flow rate, while the effects of bubble sizes on thiosulfinate extraction were not significant at the ranges tested. Application of GLD system resulted in extraction of more volatile components than other extraction methods, Therfore, it was suggested that GLD system was one of the efficient extraction methods among the ever introduced ones, for thiosulfinate extraciton.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1128-1136
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• 2007

This paper presents an application study of a model predictive control based commercial package PCTP to real chemical processes. The first case study concerns a product purity control of a splitter process which distillates styrene from undesired component ethyl-benzene produced from ethyl-benzene dehydrogenation reaction. The second case study is about a temperature control of ethyl-benzene dehydrogenation reactor and an excess oxygen control of the fired heater. Optimum control structure for MPC application is developed for each case study. The application results show a significant improvement in control performance and stability.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.701-704
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• 2001

The volatile components of citron peel extracted by three methods, which were SDE (Simultaneous steam distillation & solvent extraction) extraction, solvent extraction and supercritical carbon dioxide extraction were analyzed with gas chromatography. The operation conditions was at the temperature between $30^{\circ}C$ and $45^{\circ}C$ and perssure between 1000 psi and 2500 psi. The aromatic compound was the principal component extracted, the optimum conditions for limonene extraction were 2000 psi and $40^{\circ}C$.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.39-44
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• 2016

Suitable design and operation of distillation process is very dependent on vapor-liquid equilibrium calculation. The usual calculation method is use binary interaction parameter. Flash points of n-propanol+n-butanol and 2-butanol+n-butanol were measured by Seta-flash closed cup tester. Experimental Flash points were compared with those calculated by the method based on Raoult's law and the optimization method using Wilson equation. The binary interaction parameters obtained by the optimization method are then used to calculate the bubble points of n-propanol+n-butanol and 2-butanol+n-butanol.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.131-136
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• 2004

The ongoing developmental studies on the application of hydrogen peroxide for propulsion are briefly reviewed. A detailed design-study of a laboratory scale facility of a hydrogen peroxide mono-propellant engine of 100-N thrust is presented. For the preparation of concentrated hydrogen peroxide, a distillation facility has been realized. Results of water analogy tests are presented. Initial firings using the concentrated hydrogen peroxide were not successful. Low environmental temperature, low contact area of the catalyst pack, and contamination in the hydrogen peroxide were considered to be the reasons. Addressing the first two points resulted in successful firing of the rocket engine.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.51-55
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• 2003

Membranes made with perfluorinated polymers are of particular interest due to the unique features demonstrated by these materials. Both highly hydrophobic and hydrophilic membranes have been developed from appropriate perfluoropolymers, which were in turn obtained by copolymerization of TFE with special monomers available at the industrial scale. Highly hydrophobic membranes obtained from the glassy copolymers of TFE and 2,2,4 trifluoro-5 trifluoromethoxy-1,3 dioxole (Hyflo $n^{ }$ AD) show properties which make them particularly suited for use in the field of gas-liquid contactors and membrane distillation. Hydrophylic highly conductive proton exchange membranes obtained from the copolymer of TFE and a short-side-chain (SSC) perfluorosulfonylfluoridevinylether (Hyflo $n^{ }$ Ion) find interesting application in the field of fuel cells, especially in view of the current tendency to move to high temperature operation.n.

• Nuclear Engineering and Technology
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• v.4 no.2
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• pp.109-115
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• 1972

The evolution of radioiodine 131I from a sodium peroxide system as a function of time, temperature, and carrier gas (nitrogen) flow rate was studied. Virtually no iodine was volatilized at 25$0^{\circ}C$ and a very small amount, of the order of 10$^{-3}$ % per flour, at 63$0^{\circ}C$. Substantially greater amounts of iodine were volatilized at 7$25^{\circ}C$ and 83$0^{\circ}C$. The data are consistent with the hypothesis that the mechanism of transfer is distillation of sodium iodide, and that elemental iodine is not produced in this system.

• Journal of the Korean Society of Food Culture
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• v.21 no.4
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• pp.433-438
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• 2006

Compositional changes In essential oil of Zanthoxylum piperitum A.P. DC. were investigated under six different storage conditions for 3 months. Essential oil from Zanthoxylum piperitum was collected by steam distillation method and analyzed by gas chromatography-mass selective detector (GC-MSD). Forty-one volatile compounds, consisting of 12 hydrocarbons, 11 alcohols, 8 aldehydes, 3 oxides, 3 esters, 3 ketones and 1 acid were identified from the fresh essential oil of Zanthoxylum piperitum. In essential oils, compositional changes occurred in particularly monoterpene hydrocarbons. Total levels of ketones, esters, oxides and alcohols increased during storage. Moreover, aerobic condition caused decrease in a few constituents duringstorage even at low temperature.