Multiscale Simulation for Adsorption Process Development: A Case Study of n-Hexane Adsorption on Activated Carbon

흡착공정 개발을 위한 다중규모 모사: 활성탄에서의 n-Hexane 흡착에 관한 사례연구

  • Son, Hae-Jeong (Lab. FACS, RCCT, Department of Chemical Engineering, Hankyong National University) ;
  • Lim, Young-Il (Lab. FACS, RCCT, Department of Chemical Engineering, Hankyong National University) ;
  • Yoo, Kyoung-Seun (Department of Environment Engineering, Kwangwoon University)
  • 손혜정 (한경대학교 화학공학과 FACS 연구실) ;
  • 임영일 (한경대학교 화학공학과 FACS 연구실) ;
  • 유경선 (광운대학교 환경공학과)
  • Received : 2008.07.22
  • Accepted : 2008.08.19
  • Published : 2008.12.31

Abstract

This article presents a multi-scale simulation approach starting from the molecular level for the adsorption process development, specifically, in n-hexane adsorption on activated carbon. A grand canonical Monte-Carlo(GCMC) method is used for the prediction of adsorption isotherms of n-hexane on activated carbon at the molecular level. Geometric effects and hydrodynamic properties of the adsorption column are examined by means of the two dimensional CFD(computational fluid dynamics) simulation. The adsorption isotherms from the molecular simulation and the axial diffusivity from the CFD simulation are exploited for the process simulation where the elution curve of n-hexane is obtained. For the first moment(mean residence time) of the pulse-response with respect to temperature and flowrate, the process simulation results obtained from this three-steps multiscale simulation approach show a good agreement with experimental data within 20% of maximum difference. The multi-scale simulation approach addressed in this study will be useful to accelerate the adsorption process development, while reducing the number of experiments required.

본 연구는 활성탄을 사용한 n-hexane의 흡착공정에 있어서 분자수준에서 시작하여 공정단계에 이르는 다중규모 모사에 관하여 기술한다. 분자모사에서는 GCMC(Grand Canonical Monte Carlo) 방법을 이용하여 활성탄에서 n-hexane의 등온흡착식을 예측하고, 2차원 전산유체역학(CFD; Computational fluid dynamics) 모사를 통하여 흡착컬럼 내 유체흐름에 대한 수력학적 특성을 파악한다. 공정모사단계에서는 분자모사 및 유체역학 모사에서 각각 얻은 등온흡착식과 축방향 확산계수값을 이용하여 n-hexane의 용출곡선을 얻는다. 이러한 3단계 다중규모 모사기법을 활용하여 얻은 공정모사 결과는 펄스응답의 실험결과와 비교해볼 때, 온도와 유량변화에 따른 1차 모멘트(평균 체류시간)에 관하여 약 20% 미만의 오차범위에서 일치함을 확인할 수 있다. 이 결과로부터 분자수준에서 시작하는 다중규모 모사는 필요한 실험횟수를 줄이면서 흡착공정 개발을 가속화할 수 있는 가능성을 보여준다.

Keywords

Acknowledgement

Supported by : 한국과학재단

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