Adsorption of Alkanes and Aromatic Compounds on Various Faujasites in the Henry Domain. 2. Composition Effect in X and Y Zeolites

Abstract

Volatile organic compounds (VOCs) released in the atmosphere are responsible for important climate changes on earth, and some may have short- and long-term adverse health effects. Recovery of these VOCs can be a solution to reduce pollution. At low pressure, Henry constants are needed to develop recovery processes. Representative molecules were chosen to determine adsorption data. Nine alkanes (linear, cyclic, and branched molecules with carbon numbers between five and eight) and four aromatic and chlorinated compounds on a series of faujasite zeolites (LiLSX, NaLSX, KLSX, NaX, and two NaY) were studied in the Henry domain at temperatures ranging from (448.15 to 673.15) K using the well-known pulse chromatography technique. The zeolites were characterized to determine the main structural properties such as cell parameters, chemical composition, porous volume, specific surface area, and water adsorption capacity. The Henry constant increases with rising Si/Al ratio and probe molecule carbon number.

Removal of VOCs at trace concentration levels from humid air by Microwave Swing Adsorption, kinetics and proper sorbent selection

“…Therefore n-hexane has considerably more affinity towards NaY, which agrees well with our experimental data (Table 1): the amount of n-hexane adsorbed on NaY (107.4 ± 3.2 mg/g) is much larger than on HZY (57.6 ± 3.3 mg/g). The same authors measured Henry constants for NaY with Si/Al = 3.4 and the corresponding value for n-hexane at 448.5 K was 2025 [19], indicating lower affinity for n-hexane, in the low pressure region, as the Si/Al ratio increases. It is also important to note that in the high partial pressure region, of the n-hexane adsorption isotherm (Fig.…”

“…The adsorption capacity of the zeolites in the low partial pressure range for zeolite-VOC systems is governed by the equilibrium isotherm and in that region is determined by the slope in the Henry regime, i.e. Henry constant [18,19]. The values for the Henry constants were previously measured by other authors for ZY with Si/Al ratio equal to 2.4 exchanged with different cations.…”

Critical Evaluation of Henry’s Law Constants for Nitrogen on the NaX (13X) Zeolite

“…The evaluation of Henry’s constants for adsorption in the literature is well documented for different systems. − In the 1970s and 1980s, theoretical statistical mechanic potential models to calculate Henry’s constants K became available for zeolites. These models consider the location of all the ions in the crystal lattice cell using a three to five cell depth.…”

Adsorption of Polychlorinated Aromatics in EMT-Type Zeolites: A Combined Experimental-Simulation Approach

“…Concentrating on zeolite adsorbents, Hernandez et al used the inverse gas chromatography technique to describe the adsorption of chlorobenzene in dealuminated clinoptilolite . Furthermore, applying the pulse chromatography technique, Canet et al examined the adsorption of volatile organic compounds including chlorobenzene in faujasites (FAUs), by revealing that the zeolite chemical composition can influence the adsorption isotherms, especially in the Henry domain. Finally, some of us recently described the adsorption of dichlorobenzene (DClB) in the *BEA and/or FAU-type zeolites, respectively, from the experimental , and simulation points of view …”