Process Economics Program Report 246
Near-Zero Sulfur Diesel Fuel
Published: December 2002
Desulfurization of diesel fuel is growing worldwide into a process critical to petroleum refinery profitability. Worldwide environmental awareness led countries in the major developed regions to legislate almost sulfur-free highway diesel fuel for their markets by 2005-2007. Near zero sulfur (NZS) diesel fuel of 15 ppm sulfur or less allows advanced post engine exhaust clean up devices that remove emissions and particulate material to function.
Currently the most common sulfur specification is 500 ppm (350 ppm in Europe) with higher limits in some countries. Ultra low sulfur diesel (ULSD) fuel of less than 50 ppm becomes the specification in both the European Union and Japan in 2005. The European Commission further adopted a 10 ppm sulfur specification for road diesel fuel beginning January 1, 2005 with full conversion by 2010. An U.S. EPA rule phases in 15 ppm sulfur highway diesel fuel starting June 1, 2006. U.S. pipelines are anticipated to require a sulfur level somewhat below 10 ppm to be able to deliver less than 15 ppm fuel. In Japan, 10 ppm sulfur fuel in 2007 is proposed. Countries in other regions of the world are also working to reduce the sulfur in diesel fuel.
In order to meet these specifications, the capital investment needed by the refining industry is anticipated to be substantial (estimates range from $3 to 13 billion for the U.S. industry).
This report reviews the chemistry, technology and economics of producing diesel fuel meeting the new NZS specifications slated for 2005 and beyond. A number of improved hydrodesulfurization processes and catalysts are commercial. Adsorption and oxidation processes requiring little or no additional hydrogen are offered for license. Other processes are under development.
Revamping of existing hydrotreaters is reviewed. We evaluate the economics of a generic hydrotreating process to produce a low aromatic NZS diesel fuel.
This report should provide a useful overview of near zero sulfur diesel fuel and its properties with in-depth review of process developments and economics within the industry. People involved in the energy industry, professionals who research, develop, plan, operate, design plants or manage investments in the petroleum refining industry as well as those in allied industries could benefit from the information contained in this report.