Unified Catalytic Oxidation–Adsorption Desulfurization Process Using Cumene Hydroperoxide as Oxidant and Vanadate Based Polyionic Liquid as Catalyst and Sorbent

For the deep desulfurization of fuel oil, adsorptive desulfurization (ADS) and oxidative desulfurization (ODS) may be the most viable alternatives to the conventional HDS process. In this work, a highly cross-linked vanadate based polyionic liquid (V-PIL) was synthesized by reacting poly(vinylimidazole) (PVIM) with peroxy-vanadic acid. The as-prepared V-PIL is mesoporous with specific area of 163 m2·g–1 and good adsorptivity for the oxidized sulfur compounds. Further, it can efficiently catalyze the oxidation of dibenzothiophene and benzothiophene with cumene hydroperoxide (CHP), achieving a unified desulfurization processes of ODS and ADS. Its catalytic activity and reusability is superior to the supported vanadate catalysts, e.g. V2O5@active carbon and V2O5@zeolite. The desulfurization capacity of V-PIL is 99% in the first run under specified conditions, i.e. stirring 4 h at 323 K for 500 ppmS DBT oil, with CHP/S being 4 in mole ratio and 3 wt % V-PIL with respect to oil. And over 80% of its desulfurization capacity can be retained after five successive uses without regeneration under the above conditions. The V-PIL may represent a new type of bulk catalyst with potential application considering its rich porosity, good dispersion, accessible catalytic sites, and no soluble loss of the bonded vanadates in the recycling uses.