caa a22 4500 463170075 CHVBK 20180406164810.0 cr unu---uuuuu 170326e20070801xx s 000 0 eng 10.1007/s10450-007-9070-0 doi (NATIONALLICENCE)springer-10.1007/s10450-007-9070-0 Djekic Tanja Department of Chemical Engineering and Chemistry, Technical University of Eindhoven, Den Dolech 2, Helix, STO 1.27, P.O. Box 513, 5600MB, Eindhoven, Netherlands aut Effective intraparticle diffusion coefficients of CoCl2 in mesoporous functionalized silica adsorbents [Elektronische Daten] [Tanja Djekic] The scope of this work is to determine the effective intraparticle diffusion coefficient of CoCl2 over mesoporous functionalized silica. Silica is selected as a carrier of the functionalized groups for its rigid structure which excludes troublesome swelling, often found in polymeric adsorbents. 2-(2-pyridyl)ethyl-functionalized silica is selected as a promising affinity adsorbent for the reversible adsorption of CoCl2. The adsorption kinetics is investigated with the Zero Length Column (ZLC) method. Initially, experiments were performed at different flow rates to eliminate the effect of external mass transfer. The effect of pore size (60 Å and 90 Å), particle size (40⋅10−6m-1000⋅10−6m) and initial CoCl2 concentration (1 mol/m3-2.0mol/m3) on the mass transfer was investigated. A model was developed to determine the pore diffusion coefficient of CoCl2 by fitting the experimental data to the model. The pore diffusion coefficients determined for two different pore sizes of silica are D p (60 Å) =1.95⋅10−10 [m2/s] and D p (90 Å) =5.8⋅10−10 [m2/s]. The particle size and the initial CoCl2 concentration do not have an influence on the value of diffusion coefficient. However, particle size has an influence on the diffusion time constant. In comparison with polymer adsorbents, silica based adsorbents have higher values of diffusion coefficients, as well as a more uniform and stable pore structure. Springer Science+Business Media, LLC, 2007 Effective intraparticle diffusion coefficients nationallicence Mesoporous silica nationallicence ZLC method nationallicence b : Langmuir adsorption constant, m3/mol nationallicence C : Adsorbate concentration, mol/ m3 nationallicence C 0 : Initial adsorbate concentration, mol/ m3 nationallicence C e : Equilibrium adsorbate concentration, mol/ m3 nationallicence C NRM : Adsorbate concentration with a non-recycle mode, mol/ m3 nationallicence C RM : Adsorbate concentration with a recycle mode, mol/ m3 nationallicence C exp : Experimental adsorbate concentration, mol/ m3 nationallicence D a : Macropore diffusion coefficient, m2/s nationallicence D i : Micropore diffusion coefficient, m2/s nationallicence D p : Intraparticle diffusion coefficient, m2/s nationallicence F : Volumetric flow, ml/min nationallicence K i : Diffusion time constant, 1/s nationallicence m : Mass of adsorbent, kg nationallicence q : Loading of the adsorbent, mol/kg nationallicence $\bar{q}$ : Averaged loading of the adsorbent, mol/kg nationallicence q exp : Experimentally determined loading of the adsorbent, mol/kg nationallicence q s : Maximal loading of the adsorbent, mol/kg nationallicence r : Radial position in the particle, m nationallicence R : Radius of the particle, m nationallicence ρ S : Density of the solid, kg/m3 nationallicence t : Time, s nationallicence V : Volume of solution, m3 nationallicence V bed : Volume of the bed in the ZLC set-up, m3 nationallicence V extra : Volume of the ZLC set-up, m3 nationallicence V extra * : Volume of the ZLC set-up with empty bed, m3 nationallicence Adsorption Springer US; http://www.springer-ny.com 13/3-4(2007-08-01), 231-237 0929-5607 13:3-4<231 2007 13 10450 https://doi.org/10.1007/s10450-007-9070-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10450-007-9070-0 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Djekic Tanja Department of Chemical Engineering and Chemistry, Technical University of Eindhoven, Den Dolech 2, Helix, STO 1.27, P.O. Box 513, 5600MB, Eindhoven, Netherlands aut NATIONALLICENCE 773 0- Adsorption Springer US; http://www.springer-ny.com 13/3-4(2007-08-01), 231-237 0929-5607 13:3-4<231 2007 13 10450 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 458072745 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer