scholarly journals Factors Influencing the Kinetics of Water Vapour Adsorption on Activated Carbons

2021 ◽  
Vol 23 (3) ◽  
pp. 191
Author(s):  
Y. Boutillara ◽  
L. Richelet ◽  
L.F. Velasco ◽  
P. Lodewyckx

The performance of porous carbon materials as sorbents is often compromised by the presence of humidity. Studying the kinetics of water vapour adsorption on activated carbons will undeniably help to overcome this issue. This has been approached in this work by evaluating the influence of several operational factors on the dynamic adsorption of water vapour in these materials. Specifically, different carbon types, particle sizes, air flows and ambient conditions (temperature and relative humidity (RH)) were systematically investigated. The impact of each isolated parameter on both the maximum water uptake and the uptake rate was analyzed by fitting the experimental data to the Linear Driving Force (LDF) kinetic model. The results show that except for the particle size, the studied variables play a role in the water sorption kinetics, although to a different extent. It was also confirmed that the LDF model can adequately describe the kinetics of water vapour adsorption independently of the experimental conditions. Finally, the complete water vapour adsorption process can be described by this model, obtaining a different value of the kinetic constant for the sequential stages, involving different adsorption mechanisms.

2015 ◽  
Vol 29 (1) ◽  
pp. 115-119
Author(s):  
Aneta Ocieczek ◽  
Robert Kostek ◽  
Millena Ruszkowska

Abstract This study evaluated the kinetics of water vapour adsorption on the surface of starch molecules derived from wheat. The aim of the study was to determine an equation that would allow estimation of water content in tested material in any timepoint of the adsorption process aimed at settling a balance with the environment. An adsorption isotherm of water vapour on starch granules was drawn. The parameters of the Guggenheim, Anderson, and De Boer equation were determined by characterizing the tested product and adsorption process. The equation of kinetics of water vapour adsorption on the surface of starch was determined based on the Guggenheim, Anderson, and De Boer model describing the state of equilibrium and on the model of a first-order linear inert element describing the changes in water content over time.


2007 ◽  
Vol 82 (6) ◽  
pp. 548-557 ◽  
Author(s):  
Jorge Bedia ◽  
José Rodríguez-Mirasol ◽  
Tomás Cordero

2019 ◽  
Vol 10 (1) ◽  
pp. 22-37
Author(s):  
N. V. Guzenko ◽  
◽  
P. Lodewyckx ◽  
K. László ◽  
M. Thommes ◽  
...  

1992 ◽  
Vol 9 (4) ◽  
pp. 269-275
Author(s):  
B.M. Kats ◽  
V.V. Kutarov ◽  
A.A. Chagodar

In order to describe the kinetics of water vapour adsorption by polymeric fibres, a numeric experiment has been carried out using the framework of a non-linear diffusion model which takes into account the exponential dependence of the diffusion coefficient on the sorbate concentration in the sorbent. The results show a good correlation between theoretical and experimental kinetic curves for polymolecular adsorption. They also confirm the exponential decrease of the diffusion coefficient with an increase in polymolecular filling.


2016 ◽  
Vol 30 (3) ◽  
pp. 375-381 ◽  
Author(s):  
Alicja Szatanik-Kloc

Abstract The plant reactions on Al-stress include i.a. change of the surface area of the roots, which in the physicochemistry of plants characterizes the transport of water and ions through the root. The object of this study is the specific surface area of the roots of plants which are tolerant to aluminium, such as rye. Plants of rye were grown in a nutrient solution for 14 days at pH 4.5 in the presence of Al3+ ions of concentration 10, 20, and 40 mg dm−3. The control plants were grown continuously at pH 7 or pH 4.5 without Al3+. The apparent surface area and adsorption energy of the plants roots were determined from water vapour adsorption – desorption data. The apparent surface area of roots growing in the aluminium was (with respect to control) statistically significantly lower. There were no statistically significant differences in the apparent surface area of the roots which grew in pH 7, pH 4.5 without Al3+. The average water vapour adsorption energy of the root surface, under stress conditions decreased. In the roots grown in the presence of Al+3, there was a slight decrease in high energy adsorption centres and an increase in the amount of low-energy centres.


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