Issue
Korean Journal of Chemical Engineering,
Vol.21, No.1, 236-245, 2004
Vacuum Swing Adsorption Process for the Separation of Ethylene/Ethane with AgNO3/Clay Adsorbent
The performance of the 4-bed and 3-bed VSA process using AgNO3/clay adsorbent for the ethylene separation from C2 fractionator feed (83.56% C2H4, 16.44% C2H6) was investigated experimentally and theoretically. With the 4-bed VSA process, extremely high recovery of ethylene, over 99%, was obtained at ethylene purity of 99.8%. The recovery of the 3-bed process was lower about by 1% than that of the 4-bed VSA process. But, the productivity of the 3-bed VSA was higher about by 33% than that of the 4-bed VSA process. The productivity of the 3-bed VSA process was 3.7 mol/kg/hr at the ethylene purity of 99.8%. Effects of the rinse flow rate in the 3-bed VSA process were investigated by both experiment and simulation. The purity of ethylene was not significantly improved by the increase of the rinse flow rate after it reached 99.8%. At the rinse flow rate where the purity was 99.9%, the recovery became 70%. It might be attributed to the slow diffusion of ethane. According to the simulation, ethylene purity of over 99.9% could be obtained with recovery of over 90% only when the mass transfer rate of ethane is lower than 1.0 × 10-4 s-1 or higher than 0.2 s-1. The productivity of the process could be improved by increasing the feed flow rate at the expense of the recovery. According to the simulation, at the feed flow rate of 5,000 ml/min, the productivity of 5.2 mol/kg/hr was obtained at the ethylene purity of 99.5%.
[References]
  1. Cen PL, "Simultaneous Physical and Chemical Adsorption of Ethylene and Cu(I) NaY Zeolite," Fundamentals of Adsorption, Mersmann, A.B. and Scholl, S.E. eds., Engineering Foundation, New York, 191, 1991
  2. Chen JP, Yang RT, Langmuir, 11(9), 3450, 1995
  3. Cheng LS, Yang RT, Adsorption, 1, 61, 1995
  4. Cho SH, Han SS, Kim JN, Choudary NV, Kumar P, Bhat SGT, "Light Olefin/Paraffin Separation by Vacuum Swing Adsorption Process," 1999 AIChE Annual Meeting, Dallas, TX, Oct. 31-Nov. 5, T1027-PSA/TSA I, 1999
  5. Cho SH, Han SS, Kim JN, Choudary NV, Kumar P, Bhat SGT, "Adsorbents and Methods for the Separation of Ethylene and Propylene and/or Unsaturated Hydrocarbons from Mixed Gases," Korean Patent, 0279881, 2000
  6. Cho SH, Han SS, Kim JN, Choudary NV, Kumar P, Bhat SGT, "Adsorbents, Methods for the Preparation and Method for the Separation of Unsaturated Hydrocarbons for Mixed Gases," U.S. Patent, 6,315,816 B1, 2001
  7. Cho S, Han S, Kim J, Park J, Rhee H, Korean J. Chem. Eng., 19(5), 821, 2002
  8. Choi WK, Kwon TI, Yeo YK, Lee H, Song HK, Na BK, Korean J. Chem. Eng., 20(4), 617, 2003
  9. Choudary NV, Kumar P, Bhat TSG, Cho SH, Han SS, Kim JN, Ind. Eng. Chem. Res., 41(11), 2728, 2002
  10. Cotton FA, Wilkinson G, "Advanced Inorganic Chemistry," 2nd ed., Chaps 25 and 28, Interscience, New York, 1966
  11. Gilliland ER, Bliss HL, Kip CE, J. Am. Chem. Soc., 63, 2088, 1941
  12. Han SS, Kim JN, Cho SH, Choudary NV, Kumar P, Bhat SGT, "Adsorbents for Light Alkane/Alkene Separation," The 8th APPChE Congress, Aug. 16-19, Seoul, Korea, 1777, 1999
  13. Hirai H, "Polymers Complex for the Separation of Carbon Monoxide and Ethylene," Polymers for Gas Separation, Chap. 7, Toshima, N. ed., VCH Publishers, New York, 221, 1992
  14. Hirai H, Hara S, Komiyama M, Angew. Makromol. Chem., 130, 207, 1985
  15. Ho WS, Doyle G, Savage DW, Pruett RL, Ind. Eng. Chem. Res., 27, 334, 1988
  16. Keller GE, Marcinkowsky AE, Verma SK, Williamson KD, "Olefin Recovery and Purification via Silver Complexation," Separation and Purification Technology, Chap. 3, Li, N.N. and Calo, J.M. eds., Dekker, New York, 1992
  17. King CJ, "Separation Process Based on Reversible Chemical Complexation," Handbook of Separation Process Technology, Rousseau, R.W. ed., Chap. 15, Wiley, New York, 1987
  18. Ramachandran R, Dao LH, Brook B, "Method Producing Unsaturated Hydrocarbons and Separating the Same from Saturated Hydrocarbons," U.S. Patent, 5,365,011, 1998
  19. Rege SU, Padin J, Yang RT, AIChE J., 44(4), 799, 1998
  20. Rege SU, Yang RT, Chem. Eng. Sci., 57(7), 1139, 2002
  21. Wu ZB, Han SS, Cho SH, Kim JN, Chue KT, Yang RT, Ind. Eng. Chem. Res., 36(7), 2749, 1997
  22. Yang RT, Kikkinides ES, AIChE J., 41(3), 509, 1995