Desulfurization of gasoline by condensation of thiophenes with formaldehyde in a biphasic system using aqueous phase of acids

Aqueous phase of acids as catalysts for the desulfurization of gasoline by condensation of thiophenes with formaldehyde in a biphasic system was investigated. Two types of model gasoline with and without aromatics and olefins were employed in this work. The desulfurization rates were above 90% on these two types of model gasoline using formic acid and H3PW12O40 (0.8 mol·L− 1), indicating that the presence of aromatics and olefins has no effect on the desulfurization rate. High temperature (above 90 °C) was more favorable to the process for desulfurization. Four hours was considered to be the proper treating time for the sulfur removal. In addition, aqueous phase of acids could be recycled at least 4 times without decreasing desulfurization rate. Finally, the possible process for the integration of condensation desulfurization into the existing refinery process for the production of gasoline with low sulfur content was proposed.