Highly stable Ni/ZnO-Al 2 O 3 adsorbent promoted by TiO 2 for reactive adsorption desulfurization
Résumé
The reactive adsorption desulfurization is an important and efficient technology for the ultradeep desulfurization of gasoline. The performance of an adsorbent is vital for the efficiency of the reactive adsorption desulfurization process. In the case of Ni/ZnO-Al 2 O 3 adsorbent, the formation of inert ZnAl 2 O 4 spinels is commonly recognized for the deactivation of adsorbents. To solve this problem, in this work, TiO 2 was incorporated in the Ni/ZnO-Al 2 O 3 adsorbent by a wet impregnation method to inhibit the formation of spinel structures during the reaction and regeneration processes. The TiO 2 formed a stable protection layer on the surface of Al 2 O 3 preventing the interaction between Al 2 O 3 and ZnO, which inhibited the formation of ZnAl 2 O 4 spinel phase. The reactive adsorption desulfurization performance of the adsorbents was evaluated in a fixed bed reactor using thiophene in n-octane as a model fuel. Evaluation results indicated that the introduction of TiO 2 could significantly improve the stability of the adsorbents during cyclic hydrothermal treatments, while the sulfur capacity slightly dropped. Characterization results revealed that TiO 2 was homogeneously dispersed on the surface of Al 2 O 3 support and the incorporation of TiO 2 could maintain a certain amount of Lewis acid sites in the adsorbents, which are favorable for the adsorption of organo-sulfur compounds.
Fichier principal
8-Highly stable NiZnO-Al2O3 adsorbent promoted by TiO2 for reactive adsorption desulfurization.pdf (1022.85 Ko)
Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)