Adsorption equilibrium constants and intraparticle diffusivities in molecular sieves by tracer-pulse chromatography

AIChE Journal ◽  
1985 ◽  
Vol 31 (7) ◽  
pp. 1077-1085 ◽  
Author(s):  
S. H. Hyun ◽  
R. P. Danner
1997 ◽  
Vol 35 (7) ◽  
pp. 261-268 ◽  
Author(s):  
Kazuyuki Chihara ◽  
Kanji Oomori ◽  
Takao Oono ◽  
Yosuke Mochizuki

Supercritical CO2 regeneration is one of the possibilities for spent carbon regeneration loaded with some organics. Here, adsorption equilibrium and adsorption dynamics were evaluated for some typical organic pollutants under some supercritical CO2 conditions. A supercritical CO2 chromatograph packed with activated carbon (F-400, CAL) was used to detect the pulse responses of organics, which were analyzed by moment analysis. Adsorption equilibrium constants of some organics varied with CO2 density and their boiling points. Possibility of regeneration of each substance was discussed. Cost estimation was necessary and was the key point of this technique.


1982 ◽  
Vol 15 (3) ◽  
pp. 232-235 ◽  
Author(s):  
DONG IL LEE ◽  
MOHAMED A. FAHIM ◽  
SEIICHIRO KAGUEI ◽  
NORIAKI WAKAO

1996 ◽  
Vol 454 ◽  
Author(s):  
M. Dreyer ◽  
G. K. Newman ◽  
L. Lobban ◽  
S. J. Kersey ◽  
R. Wang ◽  
...  

ABSTRACTThis research developed new forms of photocatalysts that could potentially move photocatalytic degradation of air contaminants into the main stream of industrially used remediation technologies. Tests of the photocatalytic activity of the TiO2 aerogel catalysts have been carried out using both acetone and methane as the air contaminant. For comparison, the same tests were carried out on a standard (non-aerogel) anatase powder. Despite having very low crystallinity, the aerogel decontaminates the air far more effectively than an equal volume of the anatase powder which indicates that a much larger fraction of the aerogel is activated by the UV light. Experimental data were used to determine adsorption equilibrium constants for acetone, and to determine reaction rate constants assuming a Langmuir-Hinshelwood type rate expression.


2013 ◽  
Vol 726-731 ◽  
pp. 325-330
Author(s):  
Ming Da Liu ◽  
Feng Jiang ◽  
Hui Sun ◽  
Dan Yang ◽  
Yu Long Zhang ◽  
...  

Iron oxides play an important role in controlling P activity and availability in environmental systems. Two iron oxides (goethite and ferrihydrite) were synthesized characterized by X-ray diffraction, transmission electron microscopy and N2 adsorption method. To investigate the effect of silicon on phosphorus adsorption of them, batch equilibration method was used. Attempts were made to explore the mechanisms involved by eliminating effects of pH and accompany ions. Results reveal that the ability of two kinds of iron oxides adsorbed phosphorus were as follows: ferrihydrite > goethite. Compared with the control, silicon inhibited the adsorption of phosphorus on two iron oxides, and this effect increased with the increasing of silicon content. Langmuir, Freundlich and Temkin equations could be used to describe the adsorption characteristics of phosphorus on iron oxides well, but the Langmuir model was optimal. With silicon addition, the adsorption equilibrium constants (K) decreased of the phosphorus absorbed on iron oxide, the free energy(ΔG)dropping degree increased, the maximum adsorption capacity(Xm)and maximum buffering capacity (MBC) reduced.


2017 ◽  
Vol 396 ◽  
pp. 870-878 ◽  
Author(s):  
Xue Song ◽  
Li’ao Wang ◽  
Xu Ma ◽  
Yunmin Zeng

Author(s):  
Timur Dogu ◽  
Ebru Aydin ◽  
Nezahat Boz ◽  
Kirali Murtezaoglu ◽  
Gulsen Dogu

Effective diffusivities and adsorption equilibrium constants of methanol, ethanol and 2-methyl-2-butene (2M2B), in Amberlyst 15, were evaluated from batch adsorption experiments. Moment expressions derived for different models involving diffusion resistances in the macropores and within the gel-like micrograins were used for the evaluation of effective diffusion coefficients. Contribution of surface diffusion to diffusion flux within the macropores was found to be quite significant. Also, it was found that diffusion resistance in liquid filled macropores was much more significant than diffusion resistance within the gel-like micrograins of Amberlyst 15., for methanol, ethanol and 2M2B.


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