Volumes of gasoline/diesel interfaces cut to transmix may increase as pipelines begin transporting ultra low sulfur diesel (ULSD), according to information in the Federal Register June 2.
In publishing a proposal to amend reformulated gasoline regulations, the Environmental Protection Agency (EPA) said it had anticipated that transporting ULSD would require greater volumes of diesel to be cut as interface into other higher-sulfur distillate fuels, such as heating oil and jet fuel. However, some pipeline operators told EPA they intend to change their product sequencing by transporting volumes of ultra low sulfur diesel between volumes of gasoline, in order to minimize sulfur contamination of the ultra low sulfur diesel. This change would increase the number of gasoline/diesel interfaces cut to transmix, and increase the overall volume.
The operators also indicated that transporting ultra low sulfur diesel fuel will cause them to generate transmix at locations where they have not historically generated transmix, EPA reported.
The proposed rule would amend the reformulated gasoline regulations to allow refiners and importers of reformulated gasoline blendstock for oxygenate blending the option to use an alternative method of fulfilling a regulatory requirement to conduct quality assurance sampling and testing at downstream oxygenate blending facilities.
The proposed rule would also establish gasoline sulfur standards for transmix processors and blenders that are consistent with the sulfur standards for other entities, such as pipelines and terminals, that are downstream of refineries in the gasoline distribution system, and would clarify the requirements for transmix processors under the Mobile Source Air Toxics program.