Abstract: Methods for recovering organic heteroatom compounds from a hydrocarbon feedstock include feeding into a contactor a hydrocarbon feedstock and an aqueous solvent to form an extraction mixture of the aqueous solvent with the hydrocarbon feedstock. The hydrocarbon feedstock includes a hydrocarbon and an organic heteroatom compound. The aqueous solvent includes an ionic liquid formed from pressurized carbon dioxide and water. A pressure and temperature of the extraction mixture may be established that together tune the aqueous solvent to selectively form a solvent complex with the at least one organic heteroatom compound. Then, the solvent complex is extracted to a recovery vessel from the extraction mixture in the contactor. By adjustment of a recovery temperature of the recovery vessel, a recovery pressure of the recovery vessel, or both, the solvent complex decomposes into carbon dioxide and the organic heteroatom compound. The organic heteroatom compound is then recovered from the recovery vessel.