Design Considerations for Diesel Hydrotreaters

In 2006, the United States EPA mandated the use of 15 ppmw ultra-low sulfur diesel (ULSD) for on-road diesel fuel. At that time several refiners either revamped existing facilities or constructed grass roots facilities to meet the specification. Some facilities did not implement ULSD process capacity since they were located such that they could still easily sell off-road diesel, No.2 Fuel Oil, and/or diesel fuel to other countries that did not require ULSD. However, the number of locations that will accept higher sulfur fuel is quickly being reduced as states in the northeast set time tables for Fuel Oil desulfurization requirements, and developing nations begin to implement similar ULSD regulations. Additionally, as the market for gasoline continues to have limited growth, refiners are looking for opportunities to expand their diesel processing capacity.

In this paper, critical process design issues for hydrotreating diesel fuel to meet ULSD requirements will be updated based on the knowledge that has been gained since ULSD regulations were put in place.