Document Type : Research Paper
research institute of petroleum industry
The graphitic carbon nitride (g-C3N4) and its nanostructure have been used in the present work as the free metal catalysts for oxidative desulfurization of diesel fuel. Carbon nitride nanosheets (CNNs) were prepared via thermal exfoliation of the bulk g-C3N4 at 500℃ as an efficient approach. The structure and morphology of the synthesized samples were characterized by various techniques including XRD, FTIR, Raman Spectroscopy, FESEM, EDS, TEM and N2 adsorption–desorption and the results of these analyses confirmed that they have been successfully constructed. The factors affecting on the activity of the catalysts were studied through the Box-Behnken design as the subset of response surface methodology. It was found that CNNs had higher efficiency compared with the bulk g-C3N4. Under the optimal process conditions at H2O2 to sulfur (O/S) molar ratio of 8, temperature of 66℃, reaction time of 1h and catalyst dosage 0.12 g, 63.76% of sulfur compounds were removed from diesel oil with initial sulfur content of 5160 ppm S. Furthermore, the CNNs showed great reusability in ten cycles without significant activity reduction. Since the preparation method of g-C3N4 with suitable performance is effective and facile, CNNs can be considered to be applicable for desulfurization of real fuels in industries.