Nitrogen is a serious contaminant in natural gas because it decreases the energy density. The natural gas specification in South Korea requires a N2 content of less than 1 mol%. Thus, cost-effective N2 removal technology from natural gas is necessary, but until now the only option has been energy-intensive processes, e.g., cryogenic distillation. Using porous materials for the removal process would be beneficial for an efficient separation of CH4/N2 mixtures, but this still remains one of the challenges in modern separation technology due to the very similar size of the components. Among various porous materials, metal-organic frameworks (MOFs) present a promising candidate for the potential CH4/N2 separation material due to their unique structural flexibility. A MIL-53(Al), the most well-known flexible metal-organic framework, creates dynamic changes with closed pore (cp) transitions to open pores (ops), also called the ‘breathing’ phenomenon. We demonstrate the separation performance of CH4/N2 mixtures of MIL-53(Al) and its derivative MIL-53-NH2. The CH4/N2 selectivity of MIL- 53-NH2 is higher than pristine MIL-53(Al), suggesting a stronger CH4 interaction with NH2.

Abstract
 1. 서 론
 2. 실험 방법
  2.1 금속 유기 골격체(MOFs):MIL-53(Al), MIL-53-NH2(Al) 합성
  2.2 특성 분석
 3. 결과 및 고찰
  3.1 Textual properties
  3.2 흡착 등온선(Adsorption Isotherm)
  3.3 CH4/N2 선택도
 4. 결 론
 References

• 정민지(국립경남과학기술대학교 에너지공학과) | Minji Jung (Department of Energy Engineering, Gyeongnam National University of Science and Technology)
• 박재우(국립경남과학기술대학교 에너지공학과) | Jawoo Park (Department of Energy Engineering, Gyeongnam National University of Science and Technology)
• 오현철(국립경남과학기술대학교 에너지공학과) | Hyunchul Oh (Department of Energy Engineering, Gyeongnam National University of Science and Technology) Corresponding author