• 한국수소및신에너지학회논문집
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• 제27권3호
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• pp.290-297
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• 2016

The absorbent loss due to degradation in $CO_2$ capture process using aqueous alkanol amine solution has adverse effect on the economics of overall process. The degradation causes absorbent loss, equipment corrosion, foaming, adhesive material producing and viscosity increase in operation. In this study, the degradation characteristics of $CO_2$ capture process using MEA (monoehtanolamine) under various conditions such as $O_2$ partial pressure, $CO_2$ loading and absorbent temperature. The effects of iron, which generated from the equipment corrosion, on absorbent degradation were studied using $Fe_2SO_4$ containing MEA solution. The produced gases were analyzed by FT-IR(Fourier Transform Infrared Spectrophotometer) and the specifically measured $NH_3$ concentration was used as a degradation degree of aqueous MEA solution. The experiments showed that the higher $CO_2$ loadings (${\alpha}$), $O_2$ fraction ($y_{O2}$) and reaction temperature enhanced the more degradation of aqueous MEA solution. Comparing other operation parameters, the reaction temperature most affected on the degradation. Therefore, it could be concluded that the above parameters affects on degradation should be considered for the selections of $CO_2$ absorbent and operating conditions.

• 청정기술
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• 제11권4호
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• pp.195-204
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• 2005

기존 공정에 비하여 오염물 발생이 적고 수율이 60 % 이상의 환경친화적인 새로운 N-acyl taurate 단일축합공정을 개발하였다. 개발된 공정의 최적 운전조건은 석유계 정제유인 parasol 123 용매와 반응촉매로 sulfone산계 촉매와 인산계 촉매의 혼합촉매를 사용할 때 반응온도가 $210{\sim}230^{\circ}C$이며 반응시간이 6 ~ 9시간 이었다. 이렇게 제조된 제품은 기존 수입된 N-acyl taurate와 비교하여 산가, 아민가, 색상 등의 물성이 비슷하거나 더 좋고 부산물도 적게 배출되어 본 연구에서 개발된 공정이 기존 공정보다 우수한 공정이라고 할 수 있다. 그리고 본 연구에서 제조된 N-acyl taurate를 시판 음이온 계면활성제와 표면장력, 기포력, 기포안정성, 경수안정성, 유화력 등의 물성을 비교할 때 동등 이상의 물성을 보여 기존의 음이온 계면활성제를 충분히 대체할 수 있음을 확인할 수 있었다.

• Advances in nano research
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• 제1권2호
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• pp.83-91
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• 2013

The synthesis of semiconductor nanoparticles is a growing research area due to the prospective applications for the development of novel technologies. In this paper we have reported the biosynthesis of Cadmium sulfide nanoparticles (CdSNPs) by reduction of cadmium sulphate solution, using the bacteria of Serratia nematodiphila. The process for the synthesis of CdS nanoparticles is fast, novel and ecofriently. Formation of the CdS nanoparticles was confirmed by surface Plasmon spectra using UV-Vis spectrophotometer and absorbance strong peak at 420 nm. The morphology of crystalline phase of nanoparticles was determined from Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy and X-ray diffraction (XRD) spectra. The average size of CdS nanoparticles was in the range of 12 nm and the observed morphology was spherical. The results indicated that the proteins, which contain amine groups, played a reducing and controlling responsibility during the formation of CdS nanoparticles in the colloidal solution. Antibacterial activity against some bacteria such as Bacillus subtilis, Klebsiella planticola. CdS nanoparticles exhibiting good bactericidal activity.

• Elastomers and Composites
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• 제52권4호
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• pp.266-271
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• 2017

This study describes the influence of the amount of curing agent and curing temperature on the kinetics of polyurethane elastomers. The urethane prepolymer series was prepared by reacting toluene diisocyanate with polytetramethylene ether glycol at $80^{\circ}C$ for 1 h, and 4,4'-methylene bis(2-chloroaniline) was used as the curing agent. The ratio of the amine group of the curing agent to the isocyanate group of the urethane prepolymer was controlled from 0.85 to 1.05 at curing temperatures ranging from 80 to $120^{\circ}C$. The curing rate of the urethane prepolymer was monitored by observing the change in heat flow during the curing process using differential scanning calorimetry (DSC). As either the content of curing agent or the curing temperature was higher, the conversion rate to the polyurethane elastomer was high. The DSC results were compared with those obtained from using real-time FT-IR.

• 한국대기환경학회지
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• 제21권5호
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• pp.507-513
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• 2005

Increasing amounts of anthropogenic $CO_2$ emitted to the atmosphere are believed to be a significant factor in global climate change. Hence, the method of chemical absorption has been suggested to separate and recover acid gases such as $CO_2$. In this study, the characteristics of absorption and regeneration of $CO_2$ for the absorbent which adding HMDA (hexamethylenediamine) into AMP (2-amino-2-methyl-1-propanol), hindered amine, was investigated in lab-scale absorption/regeneration reactor. As a result of this study, the removal efficiency of $CO_2$ increased when adding $5.9\%,\;11.7\%\;and\;23.4\%$ HMDA into $30\%$ AMP respectively. Also, the removal efficiency of $CO_2$ increased $6.5\%,\;8.4\%,\;10.3\%$ respectively as compared to AMP alone when the gas flow rate was 7.5 SL/min. In addition, all absorbents used in the study revealed the high stripping efficiency, which was almost $99\%$, at the temperature of $110^{\circ}C$. Thus, the regeneration tower should be operated at $110^{\circ}C$. At this time, the concentration of exhausted $CO_2$ was higher than $99\%$.

• Journal of Pharmaceutical Investigation
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• 제35권2호
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• pp.95-99
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• 2005

Mucoadhesive microspheres were prepared by interpolymer complexation of chitosan with poly(acrylic acid) (PAA) and solvent evaporation method to increase gastric residence time. The chitosan-PAA complex formation was confirmed by differential scanning calorimetry and swelling study. The DSC thermogram of chitosan-PAA microspheres showed two exothermic peaks for the decomposition of chitosan and PAA. The swelling ratio of the chitosan-PAA microspheres was dependent on the pH of the medium. The swelling ratio was higher at pH 2.0 than at neutral pH. The results indicated that the microspheres were formed by electrostatic interaction between the carboxyl groups of PAA and the amine groups of chitosan. The effect of various process parameters on the formation and morphology of microspheres was investigated. The best microspheres were obtained when 1.5% of the high molecular weight chitosan and 0.3% of PAA were used as an internal phase. The optimum internal phase volume was 7%. The com oil was used as the external phase of emulsion, and span 80 was used as the surfactant. The prepared microspheres had spherical shape.

• 자원리싸이클링
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• 제22권2호
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• pp.3-10
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• 2013

인듐은 희유금속으로 주로 ITO제조에 사용된다. 본 총설에서는 인듐을 함유한 2차자원을 침출한 용액으로부터 인듐을 분리하기 위한 용매추출, 이온교환 및 석출법에 대한 공정 조건 및 장단점을 조사했다. 보통 정도의 산성용액에서 인듐의 추출제로 D2EHPA가 가장 많이 사용되고 있으며, 매우 강한 염산용액에서는 아민계 추출제가 사용된다. 일반적으로 이온교환수지의 인듐 흡착량이 낮으므로, 인듐의 농도가 낮은 경우에 한해 이온교환은 용매추출보다 장점이 있다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.296-301
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• 2009

The ice storage system uses water for low temperature latent heat storage. However, a refrigerator capacity is increased and COP is decreased due to supercooling of water in the course of phase change from solid to liquid. This study investigates the cooling characteristics of the TMA-water clathrate compound including TMA (Tri-methyl-amine, $(CH_3)_3N)$ of $20{\sim}25wt%$ as a low temperature latent heat storage material. The results showed that the phase change temperature and the specific heat is increased and the supercooling degree is decreased as the weight concentration of TMA increased. Especially, the clathrate compound containing TMA 25wt% has the average phase change temperature of $5.8^{\circ}C$, the supercooling degree of $8.0^{\circ}C$ and the specific heat of 3.499 kJ/kgK in the cooling process. This can lead to reduction of operation time of refrigerator in low temperature latent heat storage system and efficiency improvement of refrigerator COP and overall system. Therefore, energy saving and improvement of utilization efficiency are expected.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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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.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.299-305
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• 2011

Alloys of nylon(PA6) and ethylene-propylene-diene polymer, modified with maleic anhydride(MEPDM) were prepared using a melt kneading process. This study focuses on the effects of the content of MEPDM in PA6 blend on the mechanical and thermal properties of such blends where MEPDM is the dispersed phase. Mechanical properties were examined by stress-strain measurements and impact strength test. Both impact strength of PA6/MEPDM at room temperature and at $-20^{\circ}C$ were improved up to 400-550% with the amounts of MEPDM. However, PA6/MEPDM containing 3-5 wt% of MEPDM showed the about $700kg_f/m^2$ of the maximum tensile strength but 8.5 % of the lowest elongation. For certain compositions of PA6 with rubbery MEPDM, the interesting reduction of elongation is caused by the reaction of the polyamide amine end groups with maleic anhydride portion in MEPDM, that provided a reinforcement in the PA6 matrix. In addition, the introduction of antistatic agent on the surface of alloys causes significant reduction of their surface electrostatic resistance.