A Nonequilibrium Surface Barrier for Sorption Kinetics of p-Ethyltoluene on ZSM-5 Molecular Sieves

1994 ◽  
Vol 98 (3) ◽  
pp. 924-929 ◽  
Author(s):  
Andre Micke ◽  
Martin Buelow ◽  
Milan Kocirik
Keyword(s):  
Molecular Sieves ◽  
Sorption Kinetics ◽  
Surface Barrier ◽  
Kinetics Of

Sorption Kinetics of Xenon on MFI-Type Zeolite Molecular Sieves

1990 ◽  
Vol 94 (1) ◽  
pp. 74-76 ◽  
Author(s):  
M. Bülow ◽  
U. Härtel ◽  
U. Müller ◽  
K. K. Unger
Keyword(s):  
Molecular Sieves ◽  
Sorption Kinetics ◽  
Type Zeolite ◽  
Kinetics Of

Sorption Kinetics of p-Ethyltoluene in NaH-ZSM-5 Crystals-Simultaneous Effect of Intracrystalline Diffusion and a Mass Transport Resistance within the Crystal Surface

1994 ◽  
Vol 59 (7) ◽  
pp. 1525-1535 ◽  
Author(s):  
André Micke ◽  
Peter Struve ◽  
Martin Bülow ◽  
Milan Kočiřík ◽  
Arlette Zikánová
Keyword(s):  
Crystal Surface ◽  
Sorption Kinetics ◽  
Fickian Diffusion ◽  
Variable Pressure ◽  
Surface Barrier ◽  
Model Parameters ◽  
Equilibrium Data ◽  
Uptake Data ◽  
Kinetics Of ◽  
Rate Mechanism

Adsorption equilibrium and sorption uptake data have been measured for the system p-ethyltoluene/NaH-ZSM-5 zeolite under constant volume/variable pressure condition at elevated ambient temperature of 343 K. The equilibrium data are described by a superposition of two Langmuir isotherms. The uptake curves observed in the present paper revealed devations from the second Fick law behaviour. The experimental uptake curves are compatible with rate mechanism involving Fickian diffusion superimposed by a surface barrier. The evaluation of the model parameters was carried out by simulation of the kinetic curves that include both the interactions of the system with the apparatus and the intrinsic sorption kinetics. The dependence of the fitted model parameters on sorbent amount and pressure, respectively, is consistent with Langmuir sorption kinetics at crystal surface on one side and with the concept of molecule jumps on a system of fixed positions in the crystal bulk on the other.

Modeling of sorption kinetics of U(VI) micro-quantities nanostructured materials with anatase mesoporous structures

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Veniamin Zheleznov ◽  
Aleksey Golikov ◽  
Tatiana Sokolnitskaya ◽  
Sergey Ivannikov
Keyword(s):  
Nanostructured Materials ◽  
Sorption Kinetics ◽  
Uranyl Ion ◽  
Competitive Sorption ◽  
Hydroxyl Groups ◽  
Complex Ions ◽  
The Stability ◽  
Kinetics Of ◽  
Mesoporous Structures ◽  
Ionic Forms

Abstract The sorption kinetics of uranyl ions micro-quantities from fluoride solutions by nanostructured materials with anatase mesoporous structures has been studied. Using the model of competitive sorption of ions and positively charged complexes of uranyl ion on deprotonated hydroxyl groups of an anatase, kinetic curves of changes in the ratio of ionic forms of uranium in solution were calculated. Modeling was carried out under the assumption of a two-stage mechanism of uranium complex ions sorption. The modeling considered the influence of the uranyl ion carbonate complexes formation. The shift in equilibrium among ionic forms of uranyl correlates with the stability of the complexes in solution.

Sorption Kinetics of High Pressure Gases in Polymeric Tubing Materials

2006 ◽  
Author(s):  
P. Jaeger ◽  
S. Buchner ◽  
R. Eggers
Keyword(s):  
Diffusion Coefficients ◽  
Gas Permeability ◽  
Gravimetric Method ◽  
Sorption Kinetics ◽  
Operating Pressure ◽  
Gas Solubility ◽  
Atmospheric Conditions ◽  
High Solubility ◽  
Industrial Practice ◽  
Kinetics Of

A gravimetric method was applied to determine the sorption kinetics of gases into polymers. Diffusivity as well as sorption capacity are determined directly. Data of gas permeability that are required for calculating leakage rates in polymeric flexile gas and oil ducts may be retrieved by multiplying the obtained diffusion coefficients and the gas solubility. In general carbon dioxide enters polymers to the highest extent. In industrial practice, the high solubility of CO2 e.g. may lead to explosive decompression of sealings once the operating pressure is reduced to atmospheric conditions. Diffusion coefficients are presented in the range of 75 to 130°C at 2 to 30 MPa.

Sign in / Sign up

Export Citation Format

Share Document