Methods for treating hydrocarbon streams containing mercaptan compounds

Abstract

Disclosed is a method for treating hydrocarbon streams containing mercaptan compounds including contacting a first, relatively light hydrocarbon stream including mercaptan compounds with a first alkaline caustic solution to remove the mercaptan compounds from the first hydrocarbon stream and generate a second alkaline caustic solution including mercaptan compounds and oxidizing the mercaptan compounds in the second alkaline caustic solution to generate a third alkaline solution including a first concentration of disulfide compounds. The method further includes separating a portion of the disulfide compounds in the third alkaline solution to form a fourth alkaline solution including a second concentration of disulfide compounds. Still further, the method includes contacting the fourth alkaline solution with a second, relatively heavy hydrocarbon stream including mercaptan compounds to remove the mercaptan compounds from the second hydrocarbon stream, remove the disulfide compounds from the fourth alkaline solution, and generate the first alkaline caustic solution.