Mercaptan extraction process with recycled alkaline solution

摘要

Water is removed from an alkaline solution used to extract mercaptans from a hydrocarbon stream by contacting the alkaline solution with a warm hydrocarbon vapor stream. The relatively warm and concentrated alkaline solution produced in this manner is then passed into an oxidation zone in admixture with a mercaptan-rich alkaline solution withdrawn from an extraction zone. This process flow has operational and cost advantages compared to the passage of the stripped warm alkaline solution into the extraction zone.