연소 전 이산화탄소 포집을 위한 건식 Na-Ti계 흡수제 = Regenerable Sodium-based sorbent for CO2 capture at middle temperatures

다국어 초록 (Multilingual Abstract)

CO2 capture and regeneration properties of various sorbents prepared by physical mixing of metal oxides and alkali metals were investigated in the presence of water vapor in a fixed bed reactor during multiple cycles at middle temperatures (absorption : 200℃, regeneraion : 400℃∼550℃).
The NaTiP85 sorbents were developed in this study for CO2 capture at middle temperatures. The CO2 capture capacity of the NaTiP85 sorbent, which was prepared by physical mixing of Na2CO3 with TiO2 with 1:1 molar ratio, was 55.08 mg CO2/g sorbent in the presence of 1 vol.% CO2 and 9 vol.% vapor at 200℃. The CO2 capture capacity decreased to 31.39 mg CO2/g sorbent after 2 cycles. To investigate this result, XRD analysis was conducted. The fresh NaTiP85 sorbent formed three phases such as Na2TiO3, Na8Ti5O14, Na2Ti3O7. From XRD patterns of the NaTiP sorbents prepared by various calcination temperature, it was known that specific molecular form such like Na8Ti5O14 might be able to capture and regenerate CO2 gas. After CO2 capture, the Na8Ti5O14 phase was not found in XRD results as shown in Figure 4-14∼6 (b) and (c). These results indicate that the Na8Ti5O14 phase was transformed into Na2CO3 and a new structure during CO2 capture. However, the Na2CO3 and new structure could not be converted into original structure(Na8Ti5O14).
Even though the NaTiP85 sorbent developed in this study were not completely regenerated in the presence of 9 vol.% H2O and N2(balance gas), this sorbent was unique to be able to capture CO2 gas at middle temperatures. It was found that the sorbent couldn't capture CO2 gas without vapor at 200℃ and water vapor played an important role in the CO2 capture. In addition, the CO2 capture capacity of the NaTiP85 sorbent in high-pressure was 120 mg CO2/g sorbent in the presence of 1 vol.% CO2 with vapor at 200℃ and 20 atm.
Further study is necessary to identify the new active structure of the XRD patterns before and after CO2 capture. Considering that the CO2 capture capacity and regeneration property are very important factors in CO2 capture, the novel NaTiP85 sorbent developed in this study could be used for CO2 capture at the middle temperatures.

목차 (Table of Contents)

• 1. 서론
• 2. 연구배경 및 이론
• 2-1. 연구배경
• 2-1-1. UNFCCC 와 교토의정서
• 2-2. 연소 전 CO2 회수 및 분리기술
• 2-2-1. 습식흡수공정
• 2-2-2. 건식흡수공정
• 가. 건식 흡수제를 이용한 석탄 활용 무공해 수소발전 공정
• 나. SERP 공정(Sorption-Enhanced Steam Reforming Process)
• 2-2-3. 흡착공정
• 2-3. 국외 연구동향
• 2-3-1. 미국
• 2-3-2. 네덜란드
• 2-3-3. 호주
• 2-3-4. 영국
• 3. 실험
• 3-1. CO2 흡수제의 제조
• 3-1-1. 물리적 혼합을 이용한 CO2 흡수제 제조
• 3-1-2. 함침법을 이용한 CO2 흡수제 제조
• 3-2. 실험장치 및 방법
• 3-3. CO2 흡수력 계산
• 3-4. 제조된 CO2 흡수제의 약어 표기
• 4. 실험결과
• 4-1. SEWGS용 건식 흡수제에 적용 가능한 활성성분 선별
• 4-1-1. TPR을 통한 알칼리 금속을 첨가한 흡수제 활성평가
• 4-1-2. TPA를 통한 흡수제의 활성평가
• 4-2. Na계 SEWGS용 흡수제의 흡수‧재생 특성
• 4-2-1. Na-Ti, Na-Zr 흡수제의 흡수·재생 특성
• 4-2-2. NaTiP 흡수제의 소성온도에 따른 흡수 및 재생 특성
• 4-2-3. NaTiP 흡수제의 반복된 실험에 따른 흡수 및 재생 특성
• 4-2-4. NaTiP 흡수제의 소성온도에 따른 XRD패턴 분석
• 4-2-5. NaTi 흡수제의 반응 전후 XRD 패턴 분석과 NaTiP85 흡수제의 반응 후 TGA 분석 결과
• 4-2-6. NaTiP85 흡수제의 재생온도에 따른 흡수 및 재생특성
• 4-2-7. NaTiP85 흡수제의 성분비에 따른 흡수 및 재생 특성
• 4-2-8. NaTiP 흡수제의 수분에 대한 흡수 재생 특성
• 4-2-9. NaTi 흡수제의 제조방법에 따른 흡수 및 재생특성
• 4-2-10. NaTiP85 흡수제의 고압조건의 흡수 특성
• 5. 결론
• 6. 참고 문헌
• 부록 (Appendix)