Selective elimination of phenol from hydrocarbons by zeolites and silica-based adsorbents—Impact of the textural and acidic properties

Ibrahim Khalil (1) , Karine Thomas (1) , Hicham Jabraoui (2) , Philippe Bazin (1) , Françoise Maugé (1)

1 LCS - Laboratoire catalyse et spectrochimie
2 LPCT - Laboratoire de Physique et Chimie Théoriques

This paper investigates the parameters that influence the selective adsorption of phenol, toxic molecule, from a semi-model biofuel mixture containing alkanes and different proportions of aromatic compounds. The adsorption capacity, selectivity and regeneration ability of different adsorbents, i.e. zeolites, silica-based solids, alumina and activated carbon, were related to their textural properties and to the nature, strength or location of their acidic sites. This work demonstrates that phenol differently adsorbs in the micropores and mesopores. In the micropores of faujasites, phenol is condensed into the supercages. Otherwise, in the mesopores of the zeolite, phenol interacts with the silanol groups. On purely siliceous adsorbents, a ratio of one phenol adsorbed on one silanol group could be established. As for selectivity, the strong acidic sites of the faujasites are necessary to favor phenol adsorption compared to toluene one. By contrast, the amount of strong Brønsted and Lewis acid sites limits regeneration. Hence, a compromise has to be found and the best performances were obtained using a slightly dealuminated zeolitic adsorbent presenting both micro and mesopores.

Domaines: Chimie

Ibrahim Khalil, Karine Thomas, Hicham Jabraoui, Philippe Bazin, Françoise Maugé. Selective elimination of phenol from hydrocarbons by zeolites and silica-based adsorbents—Impact of the textural and acidic properties. Journal of Hazardous Materials, 2020, 384, pp.121397. ⟨10.1016/j.jhazmat.2019.121397⟩. ⟨hal-02345827⟩