Sulfur extraction from hydrocarbons using carbonate-based solvents

Abstract

Non-acidic sulfur compounds (e.g., thiols) can be selectively extracted from a hydrocarbon stream containing them (e.g., crude oil) by contacting the hydrocarbon stream with a carbonate solvent that contains at least one organic carbonate (e.g., propylene carbonate) in an amount effective to selectively absorb and extract the non-acidic sulfur compounds therefrom. The carbonate solvent may optionally also comprise an additional solvent (e.g., caprolactam), a soluble metal salt (e.g., a metal salt where the metal is iron), and/or a mercaptan scavenger that is a heterocyclic amine (e.g., oxazolidine).