Un-combusted diesel fuel, including ultra-low sulfur diesel (ULSD), has a strong odor. The odor often associated with diesel is unpleasant and may deter customers from purchasing diesel vehicles. In particular, the diesel fuel, when spilled, especially on one's hands or clothing, may have a prolonged bad odor. Also diesel fuel stored in equipment contained in garages, basements, sheds, or even houses can emit an odor that may make it undesirable to store the equipment or fuel indoors.
Emissions from vehicles utilizing diesel are also relatively high and require extensive after treatment technology to meet governmental regulations. Older vehicles, which do not have the extensive after-treatment equipment, should have lower emissions with this premium, odorless diesel product.
Several factors lead to diesel fuel odor. Eliminating only some of the factors can result in a diesel fuel that still has an unacceptable odor. Understanding and controlling most or all the factors is necessary to achieve a fuel that has a truly low odor level or no odor. Another important consideration is that when the odor causing components are eliminated from the prospective fuel it may no longer meet all the required specifications for the fuel. Only by careful balancing of the factors can a fuel be produced that both has low odor and meets diesel fuel specifications.
It has been discovered that some key factors in reducing or eliminating diesel fuel odor are adjusting the aromatic content, adjusting the amounts of volatile and low-boiling point compounds, and controlling the amount of sulfur and other heteroatoms in the diesel fuel.