An Experimental Design Study for CH4, C2H6 and C2H4 Adsorption and C2s/CH4 Selectivity on 10X Zeolite

Authors

Chemical Engineering Department, University of Tehran, Tehran, Iran

Abstract

CH4, C2H6 and C2H4 are the most important outlet gaseous of oxidative couple methane (OCM) reaction and this process is a new technology for conversion of natural gas to ethane and ethylene products. In this study, adsorption of OCM outlet hydrocarbons over 10X zeolite has been examined at equilibrium conditions. Temperature and pressure are the most effective operational parameters in the batch adsorption process. The central composite design was used for evaluating the effect of the operational conditions and optimization of adsorption process. The effect of temperature, pressure, their binary interaction and quadratic effects on adsorption capacity and selectivity of C2s/CH4 over 10X zeolite was determined to realize the optimal condition for enhancement of ethane and ethylene separation from methane. Optimization of the effective parameters was carried out by the statistical approach and the maximum predicted value of C2s' selectivity over CH4 was calculated 15.6, using the quadratic model at temperature of 308.15 K and atmospheric pressure. Finally, dynamic adsorption was carried out for the mixed gases at optimal conditions. Significant difference was observed between the breakthrough times of methane, ethane, and ethylene. It is concluded that 10X zeolite would be an efficient adsorbent for the separation of methane from the ethane and ethylene.

Keywords

References

[1] Lee, A., Tonkovich, Y. and Carr, R. (1994). “Modeling of the simulated countercurrent moving-bed chromatographic reactor used for the oxidative coupling of methane.” Chemical Engineering Science, 49, 4657-4665.
[2] Choi, B., Choi, D., Lee, Y. W. and Lee., B. K. (2003). “Adsorption Equilibria of Methane, Ethane, Ethylene, Nitrogen, and Hydrogen onto Activated Carbon.” J. Chem. Eng. Data, 48, 603-607.
[3] Aishah, N., Amin, S. and Pheng, S. E. (2006). “Influence of process variables and optimization of ethylene yield in oxidative coupling of methane over Li/MgO.” Chem. Eng. J., 116, 187–195.
[4] Machocki, A. and Jezior, R. (2008). “Oxidative coupling of methane over a sodium calcium oxide catalyst modified with chloride ions.” Chemical Engineering Journal, 137, oxide catalyst modified with chloride ions.” Chemical Engineering Journal, 137, 643-652.
[5] Yang, R. (1987) “Gas separation by adsorption processes.” Butterworth, Stoneham. 6- Do, D. D. (1998). “Adsorption Analysis: Equilibria and kinetics.” Imperial College Press, London.
[7] Choi, B.U., Choi, D.K., Lee, Y.W., Lee, B.K. and Kim, S.H. (2003). “Adsorption Equilibria of Methane, Ethane, Ethylene, Nitrogen, and Hydrogen onto Activated Carbon.” Journal of Chemical Engineering Data, 48, 603-607.
[8] Hosseinpour, S. (2009). “Separation of OCM Products by molecular sieve adsorbents.” MS theses, School of Chemical Engineering, Faculty of Engineering, University of Tehran.
[9] Zhu, W., Groen, J.C., Miltenburg, A.V., Kapteijn, F. and Moulijn, J.A. (2005). “Comparison of adsorption behaviour of light alkanes and alkenes on Kureha activated carbon.”  Carbon, 43, 1416-1423.
[10] Kruglov, A., Bjorklund, M. and Carr, R. (1996). “Optimization of the simulated countercurrent moving-bed chromatographic reactor for the oxidative coupling of methane.” Chemical Engineering Science, 51, 2941-2950.
[11] Siddiqi, K.S. and Thomas, W.J. (1982). “The adsorption of methane-ethane mixtures on activated carbon.” Carbon, 20, 473-479.
[12] Cavenati, S., Grande, C. A. and Rodrigues, A. E. (2004). “ Adsorption Equilibrium of Methane, Carbon Dioxide, and Nitrogen on Zeolite 13X at High Pressures.” J. Chem. Eng. Data, 49, 1095–1101.
[13] Triebe, R., Tezel, F. and Khulbe, K. (1996). “Adsorption of methane, ethane and ethylene on molecular sieve zeolites.” GUS. Sep. Purif, 10, 81-84.
[14] Macedonia, M. D., Moore, D. D. and Maginn, E. J. (2000). “Adsorption Studies of Methane, Ethane, and Argon in the Zeolite Mordenite: Molecular Simulations and Experiments.” Langmuir 16, 3823–3834.
[15] www.zeochem.com, Web site of the Zeochem Company.
[16] Antony, J. (2003). “Design of Experiments for Engineers and Scientists.” Elsevier Science & Technology Books.
[17] Santamar?a-Fernandez, R., Moreda-Pineirob, A. and Hill, S. J. (2002). “Optimization of a multielement sequential extraction method employing an experimental design approach for metal partitioning in soils and sediments.” J. Environ. Monit. 4, 330–336.
[18] Nsengiyumva, C., Beer, J. O., Wauw, W., Vlietinck, A. J. and Parmentier, E. (1997). “An Experimental Design Approach to Selecting the Optimum Liquid Chromatographic Conditions for the Determination of Vitamins B1, B2-Phosphate, B3, B6 and C in Effervescent Tablets Containing Saccharin and Sunset Yellow FCF.” Universitaire Instelling Antwerpen (UIA).
[19] Allus, M., Brereton, R. and Nickless, G. (1988), Chemometrics and Intelligent Laboratory Systems, 3, 215.
[20] Allus, M., Brereton, R. and Nickless, G. (1989), Chemometrics and Intelligent Laboratory Systems, 6, 65.

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