• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.24-28
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• 2010

Since the reaction of mineral fixation proceeds with a very slow rate, the pretreatment method to increases the rate of carbonation reaction should be required. To increase the reactivity of serpentine with $CO_{2}$, two pretreatment methods are performed in this study. The heat treatment is done at $630^{\circ}C$. A heat-treated serpentine shows that the strength of -OH has a lower peak in FT-IR spectrum. Chemical pretreatment is the method of leaching of magnesium from serpentine using sulfuric acid at $75^{\circ}C$ for 1 h. Because the protonation of the oxygen atoms polarizes and weakens the Mg-O-Si bond, the removal of magnesium atoms from the crystal lattice was facilitated. After performing the pre-treatment of serpentine, $CO_{2}$ fixation experiments are performed with treated serpentine in the batch reactor. Heat-treated serpentine is converted into 43% magnesite conversion, whereas untreated serpentine has 27% of magnesite conversion. Although the results of the heat-pretreatment are encouraging, this method is prohibited due to excessive energy consumption. Furthermore chemical pretreatment serpentine routes have been proposed in an effort to avoid the cost prohibitive heat pretreatment, in which the carbonation reaction was conducted at 45 atm and $25^{\circ}C$. Chemical-treated serpentine, in particularly is corresponded to a conversion of 42% of magnesite compared to 24% for the un-treated serpentine.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.272-277
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• 2010

To replace current expensive photobioreactor, this study was conducted to develop low-cost photobioreactor made of polyethylene bag. In previous study, optimal culture conditions of Spirulina platensis NIES 39 have been established, and based on these, the study of biological carbon dioxide fixation has been conducted. The maximum growth was the biomass 2.677 g/L at conditions of 10% $CO_2$, 0.1 vvm. It was shown that $F_{CO_2}$ was 4.056 g $CO_2$/L and $R_{CO_2}$ was 0.312 g $CO_2$/L/day. But, compared with the data at conditions of 5% $CO_2$, 0.1 vvm, $FE_{CO_2}$ was shown 52.372% which is half of it. Regarding the effect of $CO_2$ following illumination, the growth revealed that the input conditions, for 10 min per 3 h, were excellent in the light. $CO_2$ in absent light. $CO_2$ concentration and flow rate were 5% $CO_2$, 0.1 vvm, respectively. Finally, the addition of $CO_2$ was ineffective in the absence of light.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.526-532
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• 2008

The proposed $CO_2$ storage technology in the present study is a one-step sequestration process that stabilizes $CO_2$ in a reactor with Serpentine. The advantage of this technology is associated with its high stability of final product so that the entire system is recognized as permanent environment-friendly $CO_2$ removal method. Since the sequestration reaction mechanisms are generally understood that carbonation reaction proceeds with very slow rate, so that pretreatment method to increases reaction rate of $CO_2$ carbonation reaction should be developed. To increase the reactivity of Serpentine with $CO_2$, two different methods of pretreatment are carried out in the present investigation. One is heat-treatment, the other is chemical pretreatment. In this study, only chemical pretreatment is considered leaching method of magnesium from Serpentine using sulfuric acid at the various reaction temperatures, times, and acid concentrations. Experimental results illustrated that pretreatment by sulfuric acid increases surface area of serpentine from $11.1209m^2/g$ to $98.7903m^2/g$ and extracts magnesium compounds. Single variable experiment demonstrated the enhancements of magnesium extraction with increased reaction temperature and time. Amount of magnesium extraction is obtained by using the data of ICP-AES as maximum extraction condition of magnesium is 2 M acid solution, $75^{\circ}C$ and 1hr. After performing chemical pretreatment, carbonation yield increased from 23.24% to 46.30% of weight.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.71-76
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• 2000

The biological carbon dioxide fixation using microalgae has been known as an effective carbon dioxide reduction technology. With many environmental factors influencing microalgal productivity, the desirable cultivation factors were investigated using a green alga, Euglena gracilis. It has the high protein and vitamin E to be used as fodder. In batch culture with a photobioreactor, initial pH, temperature, carbon dioxide concentration and light intensity in the optimum cultivation condition were 3.5, $27^{\circ}C$,5-10% and $520{\mu}mol/m^2/s$, respectively. After that, the optimum hydraulic retention time (HRT for the continuous cultivation was 4 days at carbon dioxide concentration of 10%. In this condition, the final dry cell weight was 1.2g/l.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.389-390
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• 2000

최근 지구 온난화의 55% 이상을 차지하고 있는 이산화탄소를 유용한 화합물로 전환하고자 메탄을 환원제로 사용한 이산화탄소 개질반응으로부터 합성가스 생성에 관한 연구가 활발히 진행되고 있다. 메탄의 이산화탄소 개질반응은 수증기 개질반응보다 낮은 합성 가스비의 생성, 온실효과를 유발하는 이산화탄소의 저감, 반응의 높은 흡열도를 이용한 화학에너지 전송 시스템의 응용 면에서 그 의의가 있다. (중략)

• Bulletin of Korea Environmental Preservation Association
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• v.18 no.8
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• pp.22-28
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• 1996

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.111.2-111.2
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• 2011

최근 지구온난화로 인해 국제적으로 이산화탄소 저감에 대한 연구가 진행되고 있으며 특히, 이산화탄소의 분리 및 유용물질 전환 등의 다양한 방법에 대한 연구가 활발히 이루어지고 있다. 이산화탄소를 메탄으로 전환시키는 생물학적 반응은 acetotrophic methanogen, hydrogenotrophic methanogen 등의 미생물이 관여한다. 본 연구에서는 hydrogenotrohpic methanogen을 이용하여 메탄으로 전환하고자 하였다. 이를 위해 이산화탄소와 수소의 체류시간에 대한 연구를 진행하였으며, 선행 연구로 혐기성슬러지의 혼합배양균으로부터 hydrogenotrophic methanogen을 우점종화 하기 위해 고정층 반응기를 이용하여 이산화탄소와 수소 가스를 주입하여 고농도로 배양하였다. 그 결과, 반응기내의 이산화탄소의 메탄전환 균주로써 수소를 환원제로 이용하는 hydrogenotrophic methanogen이 배양되었음을 확인하였다. 이산화탄소와 수소가스의 체류시간에 따른 이산화탄소의 생물학적 메탄 전환 실험 결과, 약 4시간에서 이산화탄소의 저감률이 99%이었으며, 체류시간이 2시간, 1.5시간인 경우 이산화탄소의 저감률은 각각 71%, 68% 이었다.

• KSBB Journal
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• v.18 no.4
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• pp.340-345
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• 2003

Feasibility of large-scale photobioreactors for biological CO$_2$ fixation was investigated using Chlorella sp. HA-1. Generally, as the volume of photobioreactor increased, the CO$_2$ fixation rate decreased because of a lower illumination efficiency in large-scale than in small-scale photobioreactors. Though controlling the arrangement and the number of light source, the maximum CO$_2$ fixation rates that could be achieved were 530 and 357 gCO$_2$/㎡day for 40 L and 188 L photobioreactor, respectively, which was higher than the CO$_2$ fixation rate of lab-scale photobioreactor.

• KSBB Journal
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• v.14 no.6
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• pp.742-746
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• 1999

The microalgal, Chlorella sp. HA-1, had good $CO_2$ fixation efficiency compared to other algal strains at the same operating condition. In this study, Chorella sp. HA-1 showed similar tolerance both 10% and 20% $CO_2$ concentration. By optimization of the major operation variables such as pH, initial cell concentration, light intensity, the $CO_2$ fixation rate could be raised to a reasonably high value, 372 $gCO_2/m^2{\cdot}day$ in a 3 L internally illuminated photobioreactor. In order to maintain the $CO_2$ fixation rate for a long time, the method of semi-continuous operation was employed, in which dilution ratio was the controlling parameter. Starting with the dilution ratio of 0.5 with the increased increment of 0.1, the constant $CO_2$ fixation rate was obtained.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.11-17
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• 2012

This study focused on application of various $CO_2$ philic adsorbents with amine to improve $CO_2$ uptake in mortar. TGA, phenolphthalein method, FT-IR XRD, and FE-SEM analysis methods were used to evaluate $CO_2$ capture in mortar. When $CO_2$ philic adsorbents was used, $CO_2$absorption efficiency was improved maximum of 58.5%. Carbonation depth was increased 3 times compared with original mortar. Chemical reactions between bicarbonate ion, $CO_2$, $CO_2$ philic adsorbents aqueous solution, and $Ca^{2+}$ ions dissolved from cement formed $CaCO_3$ in the mortar. Therefore, impregnation of the $CO_2$ philic adsorbent on the surface of the mortar can increase the adsorbed $CO_2$.