OATAO - Open Archive Toulouse Archive Ouverte Open Access Week

Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics

Alejandro, Serguei and Valdés, Héctor and Manero, Marie-Hélène and Zaror, Claudio A. Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics. (2014) Journal of Hazardous Materials, 274. 212-220. ISSN 0304-3894

[img]
Preview
(Document in English)

PDF (Author's version) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
222kB

Official URL: https://doi.org/10.1016/j.jhazmat.2014.04.006

Abstract

In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823 K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Brønsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623 K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Brønsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity.

Item Type:Article
HAL Id:hal-01917286
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Other partners > Universidad Católica de Temuco - UCT (CHILE)
Other partners > Universidad de Concepción - UDEC (CHILE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
Other partners > Universidad Católica de la Santísima Concepción - UCSC (CHILE)
Laboratory name:
Funders:
CONICYT, FONDECYT/Regular - French National Research Agency (ANR) - ECOS/CONICYT Program - BASAL PFB-27
Statistics:download
Deposited By: Loetitia MOYA
Deposited On:09 Nov 2018 11:07

Repository Staff Only: item control page