Adsorption equilibria and kinetics of CH4 and N2 on commercial zeolites and carbons
Adsorption equilibria and kinetics are two sets of properties crucial to the design and simulation of adsorption based gas separation processes. The adsorption equilibria and kinetics of N2 and CH4 on commercial activated carbon Norit RB3, zeolite 13X, zeolite 4A and molecular sieving carbon MSC-3K 172 were studied experimentally at temperatures of (273 and 303) K in the pressure range of (5–120) kPa. These measurements were in part motivated by the lack of consistent adsorption kinetic data available in the literature for these systems, which forces the use of empirical estimates with large uncertainties in process designs. The adsorption measurements were carried out on a commercial volumetric apparatus. To obtain reliable kinetic data, the apparatus was operated in its rate of adsorption mode with calibration experiments conducted using helium to correct for the impact of gas expansion on the observed uptake dynamics. Analysis of the corrected rate of adsorption data for N2 and CH4 using the non-isothermal Fickian diffusion (FD) model was also found to be essential; the FD model was able to describe the dynamic uptake observed to better that 1% in all cases, while the more commonly applied isothermal linear driving force model was found to have a relative root mean square deviation of around 10%. The measured sorption kinetics had no dependence on gas pressure but their temperature dependence was consistent with an Arrhenius-type relation. The effective sorption rates extracted using the FD model were able to resolve inconsistencies in the literature for similar measurements.
KeywordsAdsorption kinetics Rate of adsorption Helium calibration Non-isothermal model Effective sorption rates
The research was funded by the Australian Research Council Industrial Transformation Training Centre for LNG Futures (Project IC150100019).
- Bulow, M.: Comments on the publication “ adsorption kinetics of CO2, CO, N2 and CH4 on zeolite LiX pellet and activated carbon granule” by Youngsan Ju, Yongha Park, Dooyoung Park, Jae-Jeon Kim and Chang-Ha Lee. Adsorption 21, 419–432 (2015). https://www.researchgate.net/publication/293333947_Comments_on_the_publication_Adsorption_kinetics_of_CO2_CO_N2_and_CH4_on_zeolite_LiX_pellet_and_activated_carbon_granule_by_Youngsan_Ju_Yongha_Park_Dooyoung_Park_Jae-Jeon_Kim_and_Chang-Ha_Lee_Adsorptio
- Delgado, J.A., Águeda, V.I., Uguina, M.A., Sotelo, J.L., Brea, P., Grande, C.A.: Adsorption and diffusion of H2, CO, CH4, and CO2 in BPL activated carbon and 13X zeolite: evaluation of performance in pressure swing adsorption hydrogen purification by simulation. Ind. Eng. Chem. Res. 53, 15414–15426 (2014)CrossRefGoogle Scholar
- Do, D.: Analysis of Adsorption Kinetics in a Single Homogeneous Particle, Adsorption Analysis: Equilibria and Kinetics, pp. 519–602. Imperial College Press, London (2011)Google Scholar
- Hossain, M.I.: Volume swing frequency response method for determining mass transfer mechanisms in microporous adsorbents. Doctoral dissertation. http://scholarcommons.sc.edu/etd/2585. (2014)
- Hossain, M.I.: Volumetric swing frequency response method for determining mass transfer mechanisms in microporous adsorbents. Doctoral dissertation. College of Engineering and Computing, University of South Carolina (2014)Google Scholar
- Kocirik, M., Struve, P., Bulow, M.: Analytical solution of simultaneous mass and heat transfer in zeolite crystals under constant-volume/variable-pressure conditions. J. Chem. Soc. 80, 2167–2174 (1984)Google Scholar
- Lee, L.-K., Ruthven, D.M.: Analysis of thermal effects in adsorption rate measurements. J. Chem. Soc. 75, 2406–2422 (1979)Google Scholar
- Ruthven, D.M.: Principles of Adsorption and Adsorption Processes. Wiley, New York (1984)Google Scholar
- Ruthven, D.M., Farooq, S., Knaebel, K.S.: Pressure Swing Adsorption. VCH Publishers Inc., New York (1994)Google Scholar
- Saleman, T.L.: Adsorption-Based Separations of Gaseous Nitrogen and Methane Mixtures. School of Mechanical and Chemical Engineering, The University of Western Australia, Perth (2016)Google Scholar
- Saleman, T.L., Xiao, G., Li, G., May, E.: Robust high-pressure measurements of N2 and CH4 sorption equilibrium and kinetics with an improved dynamic column breakthrough technique. Adsorption (submitted)Google Scholar