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

A method for desulfurizing a feedstock of petroleum liquid containing a sulfur compound, comprising the steps of:

• a) extracting thiophene compounds from said petroleum liquid by solvent extraction with a first solvent, to provide a petroleum liquid having residual thiophene compounds;
• b) oxidizing residual thiophene compounds in said petroleum liquid with an oxident, to provide a petroleum liquid having thiophene-oxide and thiophene-dioxide compounds;
• c) extracting thiophene-oxide and thiophene-dioxide from said petroleum liquid by extraction with a second solvent, to provide a raffinate, wherein the solvent is aqueous acetic acid;
• d) recovering the second solvent;
• e) recovering the raffinate;
• and
• f) purifying the raffinate to provide a liquid fuel product.

A method for desulfurizing a feedstock of a petroleum liquid containing a quantity of sulfur compounds, comprising the steps of:

• a) extracting thiophene compounds from said petroleum liquid by extraction with a first solvent to provide a petroleum liquid having residual thiophene compounds;
• b) oxidizing residual thiophene compounds, in said petroleum liquid;
• and
• c) extracting thiophene-oxide and thiophene-dioxide from said petroleum liquid, by extraction with a second solvent to provide a raffinate, wherein the second solvent is selected from the group consisting of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and mixtures thereof;
• d) repeating steps a-c until all of said feedstock has been treated to provide a liquid fuel product.

A method of desulfurizing of a feedstock of a petroleum liquid containing a quantity of sulfur compounds, comprising the steps of:

• a) extracting thiophene compounds from said petroleum liquid by extraction with a fist solvent, to provide a petroleum liquid having residual thiophene compounds;
• b) oxidizing residual thiophene compounds, in said petroleum liquid;
• c) extracting thiophene-oxide and thiophene-dioxide, from said petroleum liquid, by extraction with a second solvent to provide a raffinate, wherein the second solvent is selected from the group consisting of:
• acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid;
• d) recovering the second solvent;
• e) recovering the raffinate;
• f) purifying the raffinate;
• g) adsorbing the extracted thiophene-oxide and thiophene-dioxide compounds on solid bed of adsorbent;
• and
• h) repeating steps a-g until all of the feedstock has been treated, to provide a liquid fuel product.