Ionic Liquid Based Polyoxometalate as an Industrial Candidate for Extractive Desulfurization without Chemical Intermediates Production

This work involves the extractive oxidation of mixed thiophenic compounds model oil over an oxidative polyoxometalate-based catalytic system. Phosphotungstic acid-pyridine compound combining of Keggin-structured polyoxometalate anion with sulfonate functionalized cation was applied as catalyst in sulfur removal. Model oil was simulated using a mixture of the sulfur compounds dibenzothiophene, benzothiophene and thiophene in n-heptane. At optimization strategy, different extractive solvents including isopropanol, ethanol, dimethylformamid and acetonitrile in desulfurization performance were used. Some important reaction parameters including catalyst loading, dose of the oxidizing agent, existence of nitrogen compounds and aromatic hydrocarbons (toluene, xylene and mesitylene) were considered on the oxidative desulfurization (ODS) via a one-step process under optimized conditions.