Adsorption Equilibria of Aromatic Compounds on Activated Carbon, Silica Gel, and 13X Zeolite

Abstract

The adsorption of volatile organic compounds (VOCs) on the activated carbon, silica gel, and type-13X synthetic zeolite were investigated by a gravimetric adsorption method. The sorbates (VOCs) include benzene, toluene, o-xylene, p-xylene, and m-xylene. The equilibrium isotherm data obtained from this study were fitted by the Freundlich equation. The standard deviations for the predicted adsorption isotherms in the activated carbon bed were from 0.44 to 0.92, and the standard deviations were from 0.25 to 4.79 in the silica gel bed and were from 0.12 to 0.87 in the 13X zeolite bed.

Originally prepared carbon-based honeycomb monoliths with potential application as VOCs adsorbents

“…Table 2 summarizes the quantitative results obtained in the above mentioned study. As we can see, the tested monoliths exhibit a total capacity to adsorb o-xylene around 550 μmol g -1 , a value in the range of those previously reported for powdered activated carbons studied under similar experimental conditions [15]. It is also remarkable that this value, when converted into cm 3 g -1 , represents about 43% of the total micropore volume shown in Table 1.…”

A comparative study of the adsorption and desorption of o-xylene onto bentonite clay and alumina

“…These values are higher to those obtained with the bentonite and alumina since the materials reported in the literature [25][26][27][28] present extensively superior specific surfaces. However, the expression of the latter value in mol/m 2 yields to ≈3.5, 1, 3, 2.15 and 2.62 mol/m 2 for respectively AC40, CA, zeolite types Al-Meso 100, UL-ZSM5-100-2, UL-ZSM5-100-6, which is lower, as compared with the capacity of adsorption obtained with bentonite and alumina (∼8.8 mol/m 2 for alumina and 5 mol/m 2 for bentonite).…”

“…The comparison of our results with those given for the adsorption of xylene on adsorbents such as the activated carbon shows that the AC40 (1300 m 2 /g) [25], CA (990 m 2 /g) [26], zeolite types Al-Meso 100 (915 m 2 /g) [27], UL-ZSM5-100-2 (840 m 2 /g) [27], UL-ZSM5-100-6 (780 m 2 /g) [27] and AlPO 4 -5 [28], have respective capacities 4666, 1000, 2800, 1800, 2050 and 1166 mol/g. These values are higher to those obtained with the bentonite and alumina since the materials reported in the literature [25][26][27][28] present extensively superior specific surfaces.…”

Easy extrusion of honeycomb-shaped monoliths using Moroccan natural clays and investigation of their dynamic adsorptive behavior towards VOCs

“…The obtained adsorption capacities per adsorbent weight were found to be almost similar for the extruded monolith and granular forms of each studied clay. Nevertheless, these values remain lower than those reported for more porous adsorbents, for example, commercial silica [34] or activated carbon monoliths [15,22,35,36].…”