Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Adsorption Dynamics of Activated Carbon and Carbon Molecular Sieve Beds for Ethylene Recovery

배가스로부터에틸렌 회수를 위한 활성탄과 CMS 흡착탑의 흡착거동 특성

  • Yoon, Ki-Yong (Department of Chemicaland BiomolecularEngineering, Yonsei University) ;
  • Jun, Phillip (Department of Chemicaland BiomolecularEngineering, Yonsei University) ;
  • Woo, En-Ji (Department of Chemicaland BiomolecularEngineering, Yonsei University) ;
  • Ahn, Hyungwoong (Institute for Materials and Processes University of Edinburgh) ;
  • Lee, Chang-Ha (Department of Chemicaland BiomolecularEngineering, Yonsei University)
  • 윤기용 (연세대학교 화공생명공학과) ;
  • 전필립 (연세대학교 화공생명공학과) ;
  • 우은지 (연세대학교 화공생명공학과) ;
  • ;
  • 이창하 (연세대학교 화공생명공학과)
  • Received : 2011.10.11
  • Accepted : 2011.12.11
  • Published : 2012.06.01
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Abstract

The adsorption dynamics of activated carbon (AC) and carbon molecular sieve (CMS) beds were studied to recover ethylene from FCC fuel gas. In this study, the FCC fuel gas used consisted of six-component mixture ($CH_4/C_2H_4/C_2H_6/C_3H_6/N_2/H_2$,32:15:14:2:12:25 vol.%). And the breakthrough experiments of adsorption and desorption were carried out. The breakthrough sequence in the AC bed was $H_2$ < $N_2$ < $CH_4$ < $C_2H_4$ < $C_2H_6$ while the sequence in the CMS bed was $H_2$ < $CH_4$ < $N_2$ < $C_2H_6$ < $C_2H_4$. The separation performance of the CMS bed during the adsorption step was lower than that of the AC bed. However, due to the characteristics of kinetic separation, the CMS bed could remove $CH_4/N_2$ as well asthe molecules that are larger than $C_2H_6$, which was not easy to be done by the AC bed. Since it was hard to regenerate the adsorption bed by simple depressurization, vacuum regeneration should be adopted. As a result, the pressure vacuum swing adsorption (PVSA) process, consisting of CMS pretreatment process and AC main process, was suggested to recover ethylene efficiently.

FCC 연료가스로부터 에틸렌 회수를 위한 흡착공정을 개발을 위하여 활성탄(AC)과 탄소분자체(CMS)로 충진된 흡착탑의 흡착 동특성을 비교하였다. FCC 연료가스로는 6성분($CH_4/C_2H_4/C_2H_6/C_3H_6/N_2/H_2$,32:15:14:2:12:25 vol.%) 혼합가스를 이용하였으며, 흡착탑의 흡착 및 탈착파과 실험을 실시하였다. 활성탄 흡착탑의 경우 파과는 $H_2$ < $N_2$ < $CH_4$ < $C_2H_4$ < $C_2H_6$ 순서로 나왔으며, CMS 흡착탑의 경우는 $H_2$< $CH_4$ < $N_2$ < $C_2H_6$ < $C_2H_4$ 순서를 보였다. CMS 흡착탑은 활성탄 흡착탑보다 성능이 나쁘나, 속도분리의 특성으로 $CH_4$와 $N_2$뿐만 아니라 활성탄에서 제거하기 어려운 $C_2H_6$ 이상의 성분들을 흡착단계에서 제거할 수 있다. 흡착탑의 재생은 감압과정만으로는 두 흡착제 충진탑에서 충분히 재생되기 어려우며, 진공재생이 필요하다. 따라서 CMS를 이용하는 흡착공정은 전처리 공정으로 설계하고, 활성탄을 이용하는 흡착공정을 주요 분리기로 설계하는 압력진공순환식 흡착공정(PVSA)이 에틸렌 회수에 제안될 수 있다.

Keywords

References

  1. Woo, E. J., Kim, M. K., Ahn, H. W. and Lee, C. H., "Study on the Adsorption Separation Process for Recovery of Ethylene from FCC flue gas," The 2008 Spring Conference on Theories and Applications of Chemical Engineering, April, Jeju(2008).
  2. Vijender Kumar Verma, US Patent Application Publication No. US 2008/0141713 A1.
  3. James, S. D., "Ethylene Separation Process," U.S. Patent No. 4,167,402(1979).
  4. Behzad Nazar, "Rectified Reflux Deethanizer," U.S. Patent No. 5,678,424(1997).
  5. William, R. H., "Investigation of $NO_x$ Related Cold Box Incident," The 2009 Spring National Meeting, Tampa, FL.
  6. Rodrigues, A. E. and LeVan, M. D., Adsorption: Science and Technology, Kluwer Academic Publisher, 285(1989).
  7. Lee, J. J., Kim, M. K., Lee, D. G., Kim, M. J., Ahn, H., Lee, C. H., "Heat-Exchange Pressure Swing Adsorption Process for Hydrogen Separation," AIChE Journal, 54(8), 2054-2064(2008). https://doi.org/10.1002/aic.11544
  8. Kim, M. B., Bae, Y. S., Choi, D. K. and Lee, C. H., "Kinetic Separation of Landfill Gas by a Two-Bed Pressure Swing Adsorption Process Packed with Carbon Molecular Sieve: Nonisothermal Operation," Ind. Eng. Chem. Res., 45, 5050-5058(2006). https://doi.org/10.1021/ie0511074
  9. Kim, J. H., Lee, S. J., Kim, M. B., Lee, J. J. and Lee, C. H. , "Sorption Equilibrium and Thermal Regeneration of Acetone and Toluene Vaporson an Activated Carbon," Ind. Eng. Chem. Res., 46, 4584-4594(2007). https://doi.org/10.1021/ie0609362
  10. Garcia, S., Gil, M. V., Martin, C. F., Pis, J. J., Rubiera, F. and Pevida, C., "Breakthrough Adsorption Study of a Commercial Activated Carbon Forpre-combustion $CO_2$ Capture," Chem. Eng. J., 171, 549-556(2011). https://doi.org/10.1016/j.cej.2011.04.027
  11. Ling, L., Li, K., Liu, L., Miyamoto, S., Korai, Y., Kawano, S. and Moch, I., "Removal of $SO_2$ over Ethylene Tar Pitch and Cellulose Based Activated Carbon Fibers," Carbon, 37, 499-504(1999). https://doi.org/10.1016/S0008-6223(98)00219-X
  12. Lee, D. G., Kim, J. H. and Lee, C. H., "Adsorption and Thermal Regeneration of Acetone and Toluene Vapors in Dealuminated Y-Zeolite Bed," Sep. Purif. Technol., 77, 312-324(2011). https://doi.org/10.1016/j.seppur.2010.12.022
  13. Jung, B. M., Kang, S. H., Choi, H. W., Lee, C. H., Lee, B. K., and Choi, D. K., "Adsorption Equilibrium of Pure and Binary Mixture of $H_2/CH_4/C_2H_4$ on Activated Carbon," Korean Chem. Eng. Res. (HWAHAK KONGHAK), 43(3), 371-379(2005).
  14. Bae, Y. S., Moon, J. H., Ahn, H. W. and Lee, C. H., "Effect of Adsorbate Properties on Adsorption Mechanism in a Carbon Molecular Sieve," Korean J. Chem. Eng., 21(3), 712-720(2004). https://doi.org/10.1007/BF02705510
  15. Bae, Y. S. and Lee, C. H., "Sorption Kinetics of Eight Pure Gases on a Carbon Molecular Sieve at Elevated Pressure," Carbon, 43(1), 95-107(2004).
  16. Jee, J. G., Kim, M. B. and Lee, C. H., "Pressure Swing Adsorption Processes to Purify Oxygen Using a Carbonmolecular Sieve," Chem. Eng. Sci., 60, 869-882(2005). https://doi.org/10.1016/j.ces.2004.09.050
  17. Lee, C. H., Yang, J. Y. and Ahn, H. W., "Effects of Carbon-to-Zeolite Ratioon Layered Bed $H_2$ PSA for Coke Oven Gas," AIChE Journal, Vol. 45, No. 3(1999).