• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.783-787
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• 2013

The separation and capture process of carbon dioxide from power plants is garnering interest as a method to reduce greenhouse gas emissions. In this study, aqueous alkanolamine solutions were studied as absorbents for $CO_2$ capture. The solubility of $CO_2$ in aqueous alkanolamine solutions was investigated with a continuous stirred reactor at 313, 333 and 353 K. Also, the heat of absorption ($-{\Delta}H_{abs}$) between the absorbent and $CO_2$ molecules was measured with a differential reaction calorimeter (DRC) at 298 K. The solubility and heat of absorption were determined at slightly higher than atmospheric pressure. The enthalpies of $CO_2$ absorption in monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), and 2-amino-2-methyl-1-propanol (AMP) were 88.91, 70.44, 44.72, and 63.95, respectively. This investigation showed that the heat of absorption is directly related to the quantity of heat for absorbent regeneration, and is dependent on amine type and $CO_2$ loading.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.448-454
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• 2012

In this paper, a three-dimensional hydrogen absorption model is applied to a thin double-layered annulus ZrCo hydride bed and validated against the temperature evolution data measured by Kang et al. The present model reasonably captures the bed temperature evolution behavior and the 99% hydrogen charging time. The equilibrium pressure expression for hydrogen absorption on ZrCo is derived as a function of temperature and the H/M atomic ratio based on the pressure-composition isotherm data given by Konishi et al. In addition, this present model provides multi-dimensional contours such as temperature and H/M atomic ratio in the thin doublelayered annulus metal hydride region. This numerical study provides fundamental understanding during hydrogen absorption process and indicates that efficient design of the metal hydride bed is critical to achieve rapid hydrogen charging performance. The present three-dimensional hydrogen absorption model is a useful tool for the optimization of bed design and operating conditions.

• Journal of the Korean Institute of Gas
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• v.21 no.4
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• pp.76-83
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• 2017

Biogas, combine with ever-increasing natural gas demand, has been on the center stage in South Korea for the early part of twenty first century in an effort to reduce the emission of global warming gases. With the passage of legal system of City Gas Business Law in 2014, the biogas has its place of production and distribution to consumers. However, it has a room for its technological improvements in terms of enrichment, by separating carbon dioxide and removing impurities efficiently. For these improvements, four different methane enrichment processes were tested in this study; membrane separation, water absorption, Chemical Absorption and Adsorption. A variety of operation scenarios were applied to the processes and the best practices were drawn out. The optimum process was selected based on case study results. Methane produced in this study showed 97% purity and 98% recovery rate, which meets the requirements of the City Gas quality standards.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.9
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• pp.867-873
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• 2010

The failure of water-cooled generator stator windings as a result of insulation breakdown due to coolant water leaks and water absorption often occurs worldwide. Such failure can cause severe grid-related accidents as well as huge economic losses. More than 50% of domestic generators have been operated for over 15 years, and therefore, they exhibit signs of aging. Leaking and water-absorbing windings are often found during an overhaul. In an existing method for evaluating the integrity of generator stator windings, the drying process of the interior of the windings is ignored and only final leak tests are performed. In this study, it is shown that water leaks and water absorption in stator windings can be detected indirectly through vacuum pattern analysis in the vacuum drying mode, which is the used in the preparation stage of the leak test.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.294-298
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• 2005

Absorption and regeneration characteristics of sorbent used in a fluidized-bed process to capture $CO_2$ from flue gas have been measured in a thermo gravimetric analyzer. A sorbent Sorb NH prepared for fluidized-bed process was faster than pure $Na_2CO_3$ in absorption and regeneration reaction rate. Activation energy of apparent absorption reaction of sorbent Sorb NH was estimated as -10,100 cal/g mol and that of pure $Na_2CO_3$ as -12,200 cal/g mol. Activation energy of apparent regeneration reaction of sorbent Sorb NH was estimated as about 12,050 cal/g mol and that of pure $Na_2CO_3$ as about 11,320 cal/g mol.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.364-368
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• 2004

Micro Cellular Plastics create a sensation at polymer industrial for lowering product cost & overcoming a lowering of mechanical intensity. This research based on the experiment of sound absorption & transmission characteristics inquire into acoustic property of Micro Cellular Plastics. This experiment clarify the change of cell foaming rate for foaming time and the change of sound absorption & transmission for foaming rate.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.5
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• pp.603-608
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• 2010

In this study, one type of circular shaped composite tube was used, combined with reinforcing foam and without foam. Furthermore, CFRP(Carbon Fiber Reinforced Plastic) circular member manufactured from CFRP prepreg sheet for lightweight design. CFRP is an anisotropic material which is the most widely adapted lightweight structural member. The crashworthy behavior of circular composite material tubes subjected to static axial compression under same conditions is reported in this paper. Test was executed in order to compare the results to the energy absorption and collapse shape. The collapse mode during the failure process were observed and analyzed. The behavior of polymeric foams to the tubes crashworthiness were also investigated. According to the experimental results, specimens filled with foam are higher total energy absorption than the other specimens not filled with the foam.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.1
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• pp.64-72
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• 2004

On-going research has recently documented the certain tobacco specific nitrosamines (TSNAs) are formed during the curing process by an interaction of nitrogen oxides (NOx) contained in combustion gases and naturally occurring compounds in the tobacco leaves. Although the role of TSNAs in human health have been extensively investigated, little research has been conducted on the physical and chemical phenomena relating to their formation during curing. In this paper, we developed a mathematical model for describing NOx absorption into green (uncured) tobacco. We found considerable uptake of NOx by green tobacco with variations related to several factors. Specifically, tobacco from the lower stalk positions (bottom one third) absorbs more NOx gas per unit weight than tobacco from upper stalk positions. Additionally, the green tobacco packed with a density of 0.103 g/㎤ absorbs more NOx gas per unit weight than either 0.0443 g/㎤ or 0.0739 g/㎤. Further, the NOx absorption increases proportionally with temperature with the maximum absorption point around 4$0^{\circ}C$.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.2
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• pp.140-149
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• 1988

The problem of heat and mass transfer accompanying the absorption of water vapor into LiBr-$H_2O$ liquid solution flowing over the outside of the horizontal cylinder was theoretically studied to understand the absorption process occuring in the absorber of the absorption heat pump. Numerical results are presented for various quantities of interest relating to temperature, concentration, heat flux and mass flux. Also, the effects of mass flowrate, initial average velocity, and the radius of the cylinder were investigated.

• Journal of the Korean Ceramic Society
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• v.22 no.3
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• pp.29-34
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• 1985

The IR spectra of he heavy metal fluoride glasses showed peaks at $1, 400cm^{-1}$ or $1, 100cm^{-1}$ due to metal oxyfluoride impurities. The intensity of this band and hence the oxide impurity content of the glass could be reduced considerably by the use of reactive atmosphere melting under $CCl_4$ In comparison with the fundamental IR absorption band of heavy metal oxides the oxide impurity bands observed in the heavy metal fluoride glasses are multiphonon bands due to a 2-phonon absorption process. The envelope of the a vs. v curve beyond thue fundamental region shows the exponential fall off of a with increasing v-typical of intrinsic multiphonon absorption. In the multiphonon region the amount of structure is intermediate between that observed for covalent solids and that for ionic solids.