• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.239-244
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• 2007

For the simultaneous methane recovery and $CO_2$-stripping, we have been developed dual vent auto circulation bubble lift column reactor, and evaluate optimum conditions for monoethanolamine (MEA) solutions as a $CO_2$ absorbent. At the 5 wt% MEA solution, we investigated the pH change during $CO_2$-stripping and absorption reaction, $CO_2$-stripping rate with reaction time, methane recovery efficiency for various inflow rates of air, $CO_2$-stripping rate for flow liquid over flow height, and $CO_2$-stripping dependency on the temperature of absolvent solutions. The suggested optimum conditions for $CO_2$ recovery with MEA in the dual vent auto circulation bubble lift column reactor were 40 mm over flow liquid height, 1.5 L/min of air inflow rate, and $25^{\circ}C$ of absorbent solution temperature.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.505-514
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• 2009

Aqueous potassium salt of serine was proposed as an alternative $CO_2$ absorbent to monoethanolamine (MEA) and its $CO_2$ absorption characteristics were studied. The experiment has been conducted using screening test equipment with NDIR type gas analyzer and vapor-liquid equilibrium apparatus. $CO_2$ absorption/desorption rate and net amount of $CO_2$ absorbed in cyclic process are the criteria to assess the $CO_2$ absorption characteristics in this study. Effective $CO_2$ loading of potassium salt of serine and MEA are 0.425 and 0.230 respectively. Cyclic capacities are 0.354 and 0.298 for potassium salt of serine and MEA. The absorption rate of the potassium serinate decreased sharply at $CO_2$ loading is 0.1 and were maintained approximately at half of MEA. To enhance the absorption rate of aqueous potassium salt of serine, small quantities of rate promoters, namely piperazine and tetraethylenepentamine were blended, so that rich $CO_2$ loading were increased by 13.7% and 18.7% respectively. The rich $CO_2$ loading of potassium salt of serine was 29.2% and 35.0% higher than those of aqueous sodium and lithium salt of serine, respectively. The absorption rate of potassium salt of valine and isoleucine which have similar molecular structures to serine were lower than that of serine because of the presence of bulky side group. Precipitation phenomena during $CO_2$ absorption were discussed by the aid of literatures.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.44-51
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• 2006

Effects of multiple-cycle operation and $SO_2$ concentration on $CO_2$ capture characteristics of three limestones were investigated in a fluidized bed reactor. For each of these sorbents, the measured $CO_2$ capture capacity decreased as the number of cycles increased and as the $SO_2$ concentration increased. On the other hand, the $SO_2$ capture increased with the increased number of cycles and the $SO_2$ concentration. The total calcium utilization decreased as the number of cycles increased, but the effect of $SO_2$ concentrations on the total calcium utilization depended on the type of limestone. For Strassburg limestone, the total calcium utillization decreased with increasing $SO_2$ concentration. However, for Luscar and Danyang limestones, the total calcium utilization was almost independent of $SO_2$ concentration for the range investigated. The results showed that $SO_2$ in flue gas reduced the $CO_2$ capture capacity of limestone and that the sulfation pattern affected the $CO_2$ capture capacity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6439-6444
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• 2015

With increasing concern about global warming, CCS (Carbon dioxide capture and storage) has attracted much attention as a promising technology for reducing $CO_2$ emission. It is necessary to develop the cost-effective absorbents materials in order to rapid commercialize CCS technologies. In this work, he study for the promotion of absorption rate in $CO_2$ capture system using metal nanoparticle were investigated. Three kinds of metal nanoparticle, cobalt, zinc, and nickel, were prepared by wet and dry method and effect of preparation method on the absorption rate of $CO_2$ were compared. Among the tested using pH method, nickel nanoparticle prepared by wet method showed the most significant improvement of $CO_2$ absorption rate. In case that metal nanoparticle is applied to CCS process, it is expected to be more efficient in $CO_2$ capture process due to reduce the size of absorption tower.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.577-580
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• 2008

Concrete absorbs $CO_2$ in the air because of carbonation. according to rising concern for lasting earth environment efforts of reducing greenhouse gas, especially co2, are occurred whole industry throughout the world. In this paper selected one building and computed amount of production and absorbtion of co2 during its lifecycle at concrete. In computing amount of absorbtion of co2 considered amount of absorbtion according to the area of concrete changing senarioes of servicelife(40,60,80 years) and deconstruct preiod(60,40,20 years). As a result, size of concrete and maintenance period of disused concrete work increasement of $CO_2$ as main factors. We came to the conclusion that maintenance period is more important than recycle of unused concrete as a method for reducing environmental load in architectural industry.

• Journal of the Korean Magnetics Society
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• v.15 no.2
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• pp.67-75
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• 2005

For th aim of lightweight microwave absorbers, conductive and magnetic microspheres are fabricated by plating of Co films on hollow ceramic microspheres of low density. Metal plating was carried out in a two-step electroless plating process (pre-treatment of activation and plating). Uniform coating of the film with about $2{\~}3{\cal}um$ thickness was identified by SEM. High-frequency magnetic and microwave absorbing properties were determined in the rubber composites containing the Co-coated microspheres. Due to conductive and ferromagnetic behavior of the Co thin films, high dielectric constant and magnetic loss can be obtained in the microwave frequencies. Due to those electromagnetic properties, high absorption rate (25 dB) and thin matching thickness ($2.0{\~}2.5{\cal}mm$) are predicted in the composite layers containing the metal-coated microspheres of low density (about 0.84 g/cc) for the electromagnetic radiation in microwave frequencies.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.177.1-177.1
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• 2011

온실가스 감축에 대응하기 위해서 CCS기술이 지구온난화 문제를 해결하는 중요한 기술로 부각되고 있다. $CO_2$ 포집기술 중 습식법에는 대표적으로 아민, 암모니아, $K_2CO_3$와 같은 흡수제를 이용한 연구가 진행되고 있다. 본 연구에서는 $CO_2$ 포집기술 중 하나인 $K_2CO_3$ 수용액을 이용하여 Bench급 $CO_2$ 포집설비에 대한 성능을 파악하기 위한 일환으로 15% $CO_2$를 공급하여 $CO_2$ 포집 안정화 시험을 진행하였다. 압력변화 및 단수 변화를 하여 실험을 진행하였고, 흡수탑 후단의 $CO_2$ 농도를 측정하여 $CO_2$ 포집 성능을 파악하였다.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.883-892
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• 2009

We evaluated the degradation properties of various alkanolamine absorbents (MEA, AMP, DEA, and MDEA) having different chemical structures for $CO_2$ capture. The degradation of $CO_2$ absorbent in general was known to be caused by oxygen which is in flue gas and by heat source, respectively. To analyze the effect of $CO_2$ and $O_2$ on degree of degradation, we conducted a variety of experiments at $30^{\circ}C$ and $60^{\circ}C$ (oxidative degradation) and $130^{\circ}C$ and $150^{\circ}C$ (thermal degradation), respectively. DEA showed the worst property for oxidative degradation in the presence of oxygen among the alkanolamine absorbents. In the case of thermal degradation, the degradation of absorbent was occurred for most of absorbents at $150^{\circ}C$. Among these absorbents, MEA and DEA gave the worst results. As a result, AMP which is a primary amine and having a steric hindrance showed the best result through the degradation test. But, the degradation of absorbent proceeded easily in the case of DEA which is a secondary amine and having 2 OH groups in terminal position. Consequently, we have evaluated the degree of degradation of various absorbents having different chemical structures to give the basic data for the development of alkanolamine absorbent.

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.410-417
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• 2009

Carbon dioxide was absorbed into GMA solution in a stirred flat cell using mesoporous catalyst Imidazole-CP-MS41, which was synthesized by CP-MCM41 with imidazole. Experiments were carried out at a batch-type absorber with different conditions, varying reaction temperature, concentration of GMA, solvent but maintaining 50 rpm of agitation speed and 2 g of catalyst. Absorption rate of $CO_2$ was used to obtain the kinetics based on the film theory using zwitterion mechanism with 2 elementary reaction and the kinetics were correlated with the solubility parameter of the solvents.

• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.91-101
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• 2011

The purpose of this study is to demonstrate the positive effects of artificial ground greening on the reduction of carbon dioxide ($CO_2$) which can help improve ecological functions in cities and mitigation of climate change, through quantifying $CO_2$ uptake and evapotranspiration by the process of photosynthesis of some plants. Experiment of $CO_2$ uptake and evapotranspiration was conducted by measurement of $CO_2$ exchange rate using the infrared gas analyzer, for 7 month, growing season from May to November 2009, 2 times a month. The result was as follows; The $CO_2$ uptake quantity per $cm^2$ of Chrysanthemum zawadskii was the highest rate at $21.47{\times}10^{-6}g/cm^2/s$ and Poa pratensis was $16.20g{\times}10^{-6}g/cm^2/s$. The stronger was light of intensity, the higher were $CO_2$ uptake rate of most plants. In quantity of evapotranspiration, Poa pratensis was the highest rate at $8.75{\times}10^{-5}g/cm^2/s$ and Aquilegia buergariana was $8.66{\times}10^{-5}g/cm^2/s$. From this study, it is confirmed that artificial ground greening has capacity of absorption $CO_2$ and effects on improving urban microclimate.