Method of desulfurization and dearomatization of petroleum liquids by oxidation and solvent extraction

摘要

A multi-step process for desulfurizing liquid petroleum fuels that also removes nitrogen-containing compounds and aromatics. The process steps are: thiophene extraction; thiophene oxidation; thiophene-oxide and -dioxide extraction; raffinate solvent recovery and polishing; extract solvent recovery; and recycle-solvent purification. The thiophene oxidation is accomplished with hydrogen peroxide and the extraction solvent is acetic acid in combination with secondary solvents. The operating conditions in the process are relatively mild at near ambient pressure and less than 145 ° C. throughout the process, and the only chemical consumed in the process is hydrogen peroxide. The process design can be modified to accommodate a variety of liquid hydrocarbon feeds. Depending on the selected feedstock and product specifications, several process design variations are readily apparent, including the design of the extraction process sections, the solvent purification sections and the elimination of the thiophene extraction section.