Sulfur content of diesel fuel has been cut down to under 10 ppm ULSD (ultra low sulfur diesel) level by environmental regulation with the aim of reducing exhaust emissions. This review discusses the methods and principles of sulfur reduction in diesel and presents an overview of new approaches for ultra-deep desulfurization. The deep HDS (hydrodesulfurization) problems of diesel streams is exacerbated by the inhibiting effect of co-existing aromatics, nitrogen compounds and H₂S. The new approaches to deep desulfurization includes non-HDS type processing schemes such as adsorptive, extractive and oxidative desulfurization.

• 박조용(한국석유관리원 석유기술연구소) | Jo-Yong Park Corresponding author
• 김재곤(한국석유관리원 석유기술연구소) | Jae-Kon Kim
• 임의순(한국석유관리원 석유기술연구소) | Eui-Soon Yim
• 정충섭(한국석유관리원 석유기술연구소) | Choong-Sub Jung