Separation of sulfur hexafluoride (SF6) from a ternary gas mixture using polymeric hollow fiber membranes
중공사 고분자 분리막을 이용한 삼성분 (SF6, N2, O2) 혼합기체의 분리에 관한 연구
- 주제(키워드) gas separation , sulfur hexafluoride , ternary gas mixture , polysulfone hollow fiber membrane , operational condition
- 발행기관 고려대학교 대학원
- 지도교수 김성현
- 지도교수 이상협
- 발행년도 2013
- 학위수여년월 2013. 2
- 학위구분 석사
- 학과 일반대학원 화공생명공학과
- 세부전공 화공생명공학 전공
- 원문페이지 99 p
- 실제URI http://www.dcollection.net/handler/korea/000000039251
- 본문언어 영어
- 제출원본 000045745738
초록/요약
In this study, I investigated the separation of sulfur hexafluoride (SF6), which is a powerful anthropogenic greenhouse gas, using a hollow-fiber membrane. To select the appropriate membrane, the performances of various polymeric hollow-fiber membranes that are available commercially, including polysulfone (PSf), polycarbonate (PC) and polyimide (PI), for the permeation of SF6 were compared. The PSf membrane exhibited high permeability and selectivity and was thus used throughout the rest of this study. Permeation experiments using pure gas (N2, O2 and SF6) were performed to investigate the effect of temperature and pressure. To obtain more realistic information on the separation of SF6, the permeation of a ternary gas mixture (N2/O2/SF6) was also studied under various operational conditions, including pressure, temperature, stage cut (permeation flow rate/feed flow rate) and gas composition, to study the effect of these operational conditions on the performance of the membrane for the enrichment and recovery of SF6. The gas separation performance of the membrane was characterized using the selectivity, the enrichment factor, and the SF6 recovery rate. The results show that the treatment capacity increased with increasing temperature and pressure but decreased with increasing stage cut and SF6 content in the feed gas mixture. At higher temperatures, the membrane exhibited higher performance for the separation, recovery and enrichment of SF6. A feed with a higher pressure or a lower stage cut resulted in lower separation and enrichment efficiency but a higher recovery. The separation SF6 from a gas mixture with a higher content of SF6 exhibited lower recovery and enrichment performance. Using a 2-stage system, the performances of enrichment of SF6 was increased and recovery decreased.
more초록/요약
본 연구는 중공사 분리막을 이용하여 산업에서 발생되는 온실가스인 sulfur hexafluoride (SF6)의 분리에 관한 연구를 수행하였다. SF6 분리에 적합한 막을 선택하기 위하여 상업적으로 판매되고 있는 polysulfone (PSf)과 polycarbonate (PC), polyimide (PI)의 투과성능을 비교 검토하였다. 이 중PSf 막이 높은 투과도와 선택도를 나타내었다. 공급압력과 온도변화에 따른 투과특성을 확인하기 위하여 단일 기체 (SF6와N2, O6) 투과실험과 삼성분 혼합기체에서의 SF6 분리특성을 확인하기 위하여 다양한 공정 조건 (압력과 온도, stage cut, 공급기체 조성)에서 분리실험을 수행하였다. 분리 성능은 선택도와 농축 인자, 회수율을 통하여 분석하였다. 혼합기체 분리실험 결과, 온도와 압력 증가에 따라 처리유량은 증가하고, stage cut과 공급기체 조성의 증가에 따라 감소하는 것으로 나타났다. 고온 조건에 높은 분리 및 농축, 회수성능을 보였으며, 저압과 낮은 stage cut 조건에서는 분리, 농축성능은 낮아지고 회수성능은 높아졌다. 고농도의 SF6 혼합기체의 분리에서는 낮은 회수성능을 나타내었다. 또한 두개의 모듈을 이용한 2-stage system에서의 SF6 혼합기체의 분리 시 농축성능은 증가하며 회수 성능은 감소함을 확인하였다.
more목차
1. Introduction ················································································· 1
2. Background ················································································· 5
2. 1. Sulfur hexafluoride (SF6) ···················································· 5
2. 2. Gas separation technology ················································· 6
2. 3. Membrane materials ····························································12
2. 4. Membrane modules ····························································14
3. Theory ·······················································································18
3. 1. Membranes; Types and Applications ·······························18
3. 2. Membrane transport models···············································26
3. 3. Theory of gas permeation through polymer membranes···30
4. Materials & Methods ································································36
4. 1. Gas ····················································································36
4. 2. Hollow fiber membranes ····················································36
4. 3. Gas permeation experiment ··············································37
4. 4. Analysis ·············································································42
5. Results & Discussion ······························································44
5. 1. Morphological and structural characterization of membranes ·44
5. 2. Comparison of membrane performance ····························46
5. 3. Effect of operation condition on pure gas permeation ·····49
5. 3. 1. Feed pressure ·····························································49
5. 3. 2. Temperature ································································51
5. 4. Effect of operation condition on gas mixture permeation ·······54
5. 4. 1. Feed pressure ·····························································54
5. 4. 2. Temperature ································································59
5. 4. 3. Stage cut ·····································································64
5. 4. 4. Feed gas composition ················································69
5. 5. Membrane stage ·································································73
6. Conclusion ················································································75
Nomenclature ·················································································77
References ·····················································································79
Abstract in Korean ··········································································85
