Characteristics of Chlorinated VOCs Adsorption over Thermally Treated Silica Gel

열처리 실리카겔의 염소계 휘발성 유기화합물 흡착특성 연구

  • Nam, Kyung Soo (Department of Environmental Engineering, Kwangwoon University) ;
  • Kwon, Sang Soog (Department of Environmental Engineering, Kwangwoon University) ;
  • Yoo, Kyung Seun (Department of Environmental Engineering, Kwangwoon University)
  • 남경수 (광운대학교 환경공학과) ;
  • 권상숙 (광운대학교 환경공학과) ;
  • 유경선 (광운대학교 환경공학과)
  • Received : 2007.02.28
  • Accepted : 2007.04.26
  • Published : 2007.06.10

Abstract

Adsorption characteristics of 1,2-dichlorobenzene on the surface of heat treated silica gel were determined by the moment analysis. The heat treatment of the silica gel was performed at temperatures of 150, 500, and $800^{\circ}C$ and pulse-response of 1,2-dichlorobenzene was measured in a gas chromatograph equipped with thermal conductivity detector (TCD) using the packed column. Equilibrium adsorption constants and isosteric heat of adsorption were recorded the highest value at $500^{\circ}C$. This might be due to the increase of interaction between silica surface and 1,2-dichlorobenzene as the decrease of OH concentration and moisture by increase of heating temperature. Axial dispersion coefficient calculated by the moment method was about $0.046{\times}10^{-4}{\sim}1.033{\times}10^{-4}m^2/sec$ and pore diffusivity of heat treated silica gel at $500^{\circ}C$ measured the lowest value. Because heat treating at $800^{\circ}C$ caused the specific surface area to reduce, equilibrium adsorption constants and isosteric heat of adsorption were decreased.

실리카겔의 열처리 온도에 따른 1,2-dichlorobenzene의 흡착 특성을 모멘트 법으로 고찰하였다. 실리카겔의 열처리 온도는 150, 500, $800^{\circ}C$로 변화시켰으며 고정층 반응기를 사용하여 TCD (Thermal Conductivity Detector)가 장착된 기체크로마토 그래프에서 1,2-dichlorobenzene의 펄스 응답곡선을 측정하였다. 1,2-dichlorobenzene의 평형흡착상수와 표면 흡착열은 열처리 온도 $500^{\circ}C$에서 가장 높은 값을 나타내었다. 열처리 온도가 증가함에 따라 실리카겔 표면의 수분과 OH 작용기가 제거되어 1,2-dichlorobenzene과의 상호작용이 증가한 것으로 판단된다. 고온인 $800^{\circ}C$에서 열처리한 실리카겔은 비표면적이 감소하여 평형흡착상수와 흡착열, 모두 감소한 것으로 사료된다. 모멘트 해석으로 계산된 축분산 계수는 $0.046{\times}10^{-4}{\sim}1.033{\times}10^{-4}m^2/sec$였으며 기공 내의 확산계수는 $500^{\circ}C$ 열처리 실리카겔에서 가장 낮은 것으로 나타났다.

Keywords

Acknowledgement

Supported by : 한국과학재단

References

  1. J. W. Shin, Master Thesis, Kwangwoon Univ., Seoul, Korea (2003)
  2. J. W. Shin and K. S. Yoo, J. Ind. Eng. Chem., 12, 418 (2006)
  3. S. C. Kim and I. K. Hong, J. Ind. Eng. Chem., 4, 177 (1998)
  4. D. M. Ruthven, Principle of Adsorption and Adsorption Process, 1, 6, John Wiley and Sons, New York (1984)
  5. P. Schneider and J. M. Smith, AIChE J., 14, 762 (1968) https://doi.org/10.1002/aic.690140516
  6. L. T. Zhuravlev, Colloid and Surface J., 173, 1 (2000) https://doi.org/10.1016/S0927-7757(00)00556-2
  7. Z. Li, C. Liu and Q. Zhao, J. Non-cryst., 265, 189 (2000)
  8. P. N. Breysse, A. M. Cappabianca, T. A. Hall, and T. Risby, Carbon, 25, 803 (1987) https://doi.org/10.1016/0008-6223(87)90155-2
  9. K. Chihara, M. Suzuki, and K. Kawazoe, AIChE J., 24, 237 (1978) https://doi.org/10.1002/aic.690240212
  10. J. R. Welty, C. E. Wicks, and R. E. Wilson, Fundamentals of Momentum, Heat, and Mass Transfer, 3, 487, John Wiley and Sons, New York (1984)
  11. P. Schneider and J. M. Smith, AIChE J., 14, 886 (1968) https://doi.org/10.1002/aic.690140613
  12. X. Yang and M. A. Matthews, Chem. Eng. J., 93, 163 (2003) https://doi.org/10.1016/S1385-8947(02)00254-1