• 대한치주과학회:학술대회논문집
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• 1999.11a
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• pp.32-33
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• 1999

• The Journal of the Korean dental association
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• v.36 no.7 s.350
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• pp.497-502
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• 1998

• Journal of Energy Engineering
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• v.14 no.3 s.43
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• pp.203-211
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• 2005

To investigate the effects of the number of multiple-cycles and $SO_2$ concentration on $CO_2$ absorption characteristics by means of limestone, $CO_2$ capture capacity has been measured in a bubbling fluidized bed reactor (0.1m 1.D., 1.17m high). Danyang limestone was used as a $CO_2$ sorbent and the number of cycles $(\~10th\;cycle)$ and $SO_2$ concentrations (0, 2000, 4000 ppm) were considered as variables. The measured $CO_2$ capture capacity decreased as the number of cycles increased and it showed $50\%$ or initial value after 10 cycles. Moreover, $CO_2$ rapture capacity decreased with 501 concentrations. For three different $SO_2$ concentrations, the total CaO utilization was almost the same but $SO_2$ capture capacity increased and $CO_2$ capture capacity decreased as $SO_2$ concentration increased. These results suggest that $SO_2$ capture reaction is predominant over $CO_2$ capture reaction in the simultaneous $CO_2/SO_2$ capture conditions.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.185-188
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• 2005

나노 입자 분무 기법을 이용한 $Cu(In,\;Ga)Se_2$ (CIGS) 광흡수층 제조 기법은 고진공 장치를 사용하지 않는다는 점에서 대면적 저가형 CIGS 태양전지 양산에 적합한 차세대 기술로 인식되고 있다. 그러나 일반적으로 스프레이 된 상태의 CIGS충 자체는 태양전지 제조에 적합하지 않은데 이는 스프레이 막의 다공성 구조 때문이다. 본 연구에서는 나노입자 분무 기법을 이용하여 증착한 CIGS 광흡수층막을 질소 또는 셀레늄 분위기에서 열처리함으로써 태양전지 제조에 적합한 치밀한 구조의 CIGS 광흡수충을 제조하고자 하였다. 실험 결과, 질소 분위기 $500^{\circ}C$의 온도에서 1시간 열처리하여도 CIGS 나노 입자의 성장은 거의 일어나지 않는 것으로 나타났다. 반면 셀레늄 분위기 $500^{\circ}C$의 온도에서 30분 열처리시 입자 크기가 $1{\mu}m$이상인 치밀한 광흡수층을 얻을 수 있었다. 본 결과는 CIGS 나노 입자의 입자 성장 반응에서 열에너지 단독에 의한 표면 에너지 감소 효과는 미미하며 셀레늄 증기의 역할이 더욱 크다는 것을 의미하는 것이다.

• Clean Technology
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• v.27 no.3
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• pp.255-260
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• 2021

A drawback in the CO₂ capture process using an aqueous amine solution is the high energy requirement for the regeneration process. In order to overcome this disadvantage, this study investigated CO₂ capture characteristics using a biphasic absorbent in which isopropanol (IPA) was introduced into an aqueous solution of diethylenetriamine (DETA). When the IPA composition exceeded 20 wt% in 20 wt% DETA aqueous solution, the absorbent phase was liquid-liquid separated into a CO₂-rich phase and a CO₂-lean phase because of the low solubility of the salt formed by the reaction of CO₂ with DETA in isopropanol. When the isopropanol composition in the DETA aqueous solution increased, the phase volume ratio of the CO₂-rich phase to the volume of the CO₂-lean phase increased; and, accordingly, the CO₂ in the CO₂-rich phase was more concentrated. The results of absorbing CO₂ in a packed tower using 20 wt% DETA + IPA + water absorbent confirmed that both the CO₂ absorption capacity and the absorption rate were higher than that of the 20 wt% DETA aqueous solution. When a biphasic absorbent composed of DETA + IPA + water is applied to CO₂ capture, it can be expected to concentrate CO₂ because of phase separation and thereby reduce regeneration energy owing to volume reduction of the CO₂-rich phase.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.654-658
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• 2012

In this study, $CO_2$ capture efficiency in relation to the inlet moisture content of the regenerator was investigated using potassium-based sorbents in the continuous process composed of two bubbling fluidized-bed reactors, where solid outlet configuration in the regenerator was converted from underflow to overflow. XRD (X-ray Diffraction), SEM (Scanning Electron Microscope) and TGA were performed to find out the effect of water pre-treatment according to inlet moisture content in the regenerator. The $K_2CO_3{\cdot}1.5H_2O$ structure of solid sorbents has been increased as inlet moisture content of the regenerator increased. As a result, the $CO_2$ capture efficiency increased as the $K_2CO_3{\cdot}1.5H_2O$ structure of solid sorbents increased since the reactivity of the sorbents has been improved by that structure generated by the water pre-treatment. And $CO_2$ capture efficiency increased about 3~8% after sorbent outlet configuration of the regenerator was changed underflow to overflow.

• Bulletin of Korea Environmental Preservation Association
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• v.19 no.8
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• pp.27-29
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• 1997

• Journal of Energy Engineering
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• v.7 no.1
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• pp.24-34
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• 1998

In this research, effects of the types and amounts of binders and additives on desulfurization and regeneration reactivities of zinc titanate were investigated. Bentonite and kaolinite were used as binders and Mo-based, Ni-based, and Cu-based compounds were used as additives. A thermogravimetric analyzer (TGA) was utilized to investigate reactivities of desulfurization and regeneration for each sorbent. Two-cycle reactions of desulfurization-regeneration were performed in the TGA reactor. Results of XRD analysis showed that all sorbents had the crystalline phases of $Zn_2TiO_2$ and $Zn_2Ti_3O_8$ irrespective of the type and amount of binder and additive. Kaolinite-bound sorbents gave higher surface areas than bentonite-bound ones and the surface areas and pore volumes of sorbents increased with amount of binder increased. It was found that the most suitable temperatures for desulfurization and regeneration were 680$^{\circ}$C and 730$^{\circ}$C, respectively, and the sorbent prepared by the addition of 3 mol% CuO showed the best performance in terms of desulfurization and regeneration. Nio-added sorbents had good regenerability whereas $MoO_3-based$ sorbents showed poor performance. In cycle experiments in a fixed bed reactor 3 mol% CuO-added sorbents showed high reactivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4627-4634
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• 2013

Carbon dioxide is one of the main causes of global warming. In order to develop a novel absorbent, the characteristics of amino acid salts solution as a solvent for $CO_2$ capture in continuous process were investigated. The cost of $CO_2$ capture is almost 70% of total cost of CCS (carbon dioxide capture and storage). In the carbon dioxide capture process, process maintenance costs consist of the absorbent including the absorption, regeneration, degradation, and etc. It is very important to study the characteristics of absorbent in continuous process. In this study, we have investigated the properties of potassium L-lysine (PL) for getting scale-up factors in continuous process. To obtain optimum condition for removal efficiency of $CO_2$ in continuous process by varying liquid-gas (L/G) ratio, concentration of $CO_2$ and absorbent (PL) were tested. The stable condition of absorber and regenerator (L/G) ratio is 3.5. In addition, PL system reveals the highest removal efficiency of $CO_2$ with 3.5 of L/G and 10.5 vol% $CO_2$ ($1.5Nm^3/h$).

• Plant Journal
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• v.8 no.4
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• pp.40-44
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• 2012

The pre-treatment of natural gas to remove $H_2S$ and $CO_2$ before liquefaction in natural gas processing is required, and amine-based absorption processes are widely used in gas processing. The current study aims to model amine-based absorption process and to find cost-effective design through systematic analysis of energy systems, together with column design. Different design options for absorber and stripper are investigated in a holistic manner, and heat integration technique has been applied to investigate how design of columns is interacted with energy efficiency for the pre-treatment process considered. Case study has been presented to demonstrate the applicability of heat integration method for improving energy efficiency in practice.