Premium
Transport of n ‐paraffins in zeolite T
Author(s) -
Magalhães Fernão D.,
Laurence Robert L.,
Conner William Curtis
Publication year - 1996
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690420108
Subject(s) - heptane , zeolite , sorption , dodecane , saturation (graph theory) , thermodynamics , chemistry , gravimetric analysis , mass transport , desorption , hydraulic resistance , mechanics , physics , adsorption , mathematics , organic chemistry , catalysis , combinatorics , engineering physics
Mass transport of n‐heptane, n‐nonane, and n‐dodecane in zeolite T was studied using a gravimetric uptake technique. The sigmoidal shape of the uptake curves indicated the existence of a nondiffusional resistance in the transport process. To compute the transport parameters, an approach based on the temporal moments of the uptake curves was developed. A model involving an external resistance dependent on the local slope of the sorption isotherm best represented the data. No evidence of the “window effect” reported by Gorring was found. The measured diffusivities decrease with chain length, while the activation energies remain essentially constant. Both resistances (diffusional and nondiffusional) depend strongly on lattice loading, and their relative contributions for the transport time change as saturation is approached.