Clean Technology (청정기술)

The Korean Society of Clean Technology (한국청정기술학회)
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Investigation of Coke Formation on H-ZSM-5 Catalyst During Aromatization of C5 Paraffin and Olefin Using Optical and Fluorescence Microscopy

  • Chung, Young-Min (Department of Nano & Chemical Engineering, Kunsan National University)
  • Received : 2013.07.03
  • Accepted : 2013.07.11
  • Published : 2013.09.30
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Abstract

Space- and time-resolved in-situ optical and fluorescence microspectroscopy techniques have been applied to investigate the coke formation during aromatization of C5 paraffin and olefin over H-ZSM-5 crystal. In-situ UV/vis absorption measurement offers space- and time-resolved information for the coke formation. Different coking trends have been observed with respect to the location of a crystal as well as the reactant types. From in-situ confocal fluorescence microspectroscopy study, it is revealed that the concentration of certain species photo-excited at 488 nm becomes high at the central region, whereas the compounds emitting fluorescence by 561 nm laser move towards the boundary region of the crystal. The different fluorescence patterns obtained varying excitation lasers suggest the existence of distinct fluorescence emitting species having different degree of coke growth.

광학 및 형광 현미경을 이용한 실시간 촉매 모니터링 기술을 활용하여 C5 파라핀과 올레핀의 방향족화 반응 중 H-ZSM-5 촉매 표면에서 발생하는 코크 형성 과정을 시간별, 촉매 위치별로 관찰하였다. 실시간 자외-가시광 분광현미경(in-situ UV-vis microspectroscopy) 실험을 통해 반응 중 촉매 표면에서 발생하는 코킹 현상에 대한 정보를 실시간으로 얻을 수 있었으며, 그 결과, 결정의 위치와 반응물의 종류에 따라 코크 형성이 크게 달라짐을 확인하였다. 실시간 공초점형 형광현미경(in-situ confocal fluorescence microscopy) 연구에서는, 488 nm 레이저에 의해 형광을 나타내는 화학종들은 높은 분포로 결정의 중앙부분에 존재하며, 561 nm 레이저에 의해 형광을 발현하는 화학종들은 촉매 결정의 외곽으로 이동하는 것을 관찰하였다. 이러한 결과는, 코크 전구체의 크기에 따라 형광 발현 현상이 다르며, 따라서, 촉매의 위치에 따라 다른 종류의 코크 전구체가 존재한다는 것을 시사한다.

Keywords

References

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