THE PETROLEUM logistics system in the United States should be ready when the Environmental Protection Agency's requirements for ultra low sulfur diesel (ULSD) take effect in mid-2006. The most serious production and distribution issues appear to have been resolved.
To reach this point, refineries, pipelines, terminals, and other participants in the petroleum logistics system have spent more than $8 billion, and there's still more investment to come. On the vehicle side, manufacturers have made significant investments in engines and emission control systems that are designed specifically for ULSD fuels.
“We've made good progress in all areas, said Paul Machiele, EPA Office of Transportation and Air Quality. Machiele was one of a series of speakers discussing the ULSD issue during the Independent Liquid Terminals Association's 25th Annual International Operating Conference & Trade Show June 6-8 in Houston, Texas.
“New engines for ULSD fuel will be ready on schedule,” he said. “Most importantly, ULSD will be in production on time and in sufficient quantity to meet market demand. It will be available nationwide.
“In recent months, we held a series of progress meetings with refiners, pipelines, terminals, and others. We verified that refiners are on-track to meet the 2006 deadlines. At pipelines and terminals, engineering analyses are essentially complete, and they have begun investing in system upgrades. Pipelines and terminals still need to implement record keeping/reporting processes for compliance obligations.”
Three key issues
Three main logistics issues have been highlighted in the progress meetings — sulfur testing uncertainty, pipeline company desire for early testing of ULSD, and a need for additional transition flexibility. These issues are almost certain to be on the agenda of an implementation workshop that has tentatively been scheduled for November. Date and location for the workshop are still to be determined.
Even as they wrestle with various issues, companies in the supply chain need to keep a key deadline in mind. Any entity that produces, imports, or maintains custody of fuel from the time fuel is received until it is transferred to another party must be registered with EPA by December 31. Facilities won't be allowed to receive or distribute fuel without that registration.
Terminals also need to move ahead with upgrade plans to meet ULSD requirements. Many of the facilities will need to install injection systems for static dissipater and lubricity additives.
Static dissipater additives will be needed because base fuel conductivity of ULSD will be extremely low — virtually all trace polar materials are removed during processing. Electrostatic hazards at the terminal will be as much as 30 times higher for ULSD, compared with higher-sulfur fuels, according to Cyrus P Henry Jr, Octel America.
“Electrostatic charging can be minimized, but not eliminated, by revising operating procedures,” he said. “Sparking sources also can be minimized. Those steps may not be enough, though. Static dissipater additives (SDAs) may be the only other alternative.
“Continuous injection into receiving storage tanks is preferred,” Henry said. “However, injection at loading racks is satisfactory provided fail-safes are in place. Finally, injection equipment must be reliable and properly maintained.”
Lubricity additives
Lubricity additives will be needed in ULSD fuel even more than they are in the current low-sulfur diesel used by heavy-duty truck engines. ULSD has virtually no lubricating capability of its own. Lubricity used to come from higher levels of sulfur in the diesel.
Lubricity additives offset the lack of sulfur to protect and extend the life of the diesel engine fuel injection system, according to Philip S Korosec, MidContinental Chemical Company. Lubricity additives also should provide corrosion protection and should have the ability to shed water and function under all climate conditions.
Four basic types of lubricity additives are coming to the market. Acid-based additives consist of fatty acids derived from renewable sources or synthetic acids. Ester- and amide-based products are derived from fatty acids or synthetic acids. The fourth category is polymer based.
Researchers have found problems with some of the additive materials that have been tested. For instance, dimer and trimer acids have been tested but have caused problems in the field. Plugged fuel filters were the biggest problem.
While the refinery is the most convenient place for additive injections, it's not going to happen there for ULSD fuels. Pipeline operators said last year that they would not accept any ULSD shipments with static dissipater or lubricity additives.
Terminal injection
As a result, petroleum terminals and bulk plants will have the primary responsibility for injecting additives. “Within the terminal, operators have three options,” said Jack Kiefert, Lubrizol Performance Systems. “They can additize when the fuel goes into storage, and this is probably the least expensive option. The downside is that the additive could be lost in storage, which means a greater quantity of additive will be required.”
The next option is to inject additives when the fuel is pumped to the loading rack. On the plus side, the total cost of equipment is relatively low. However, variations in product flow rates could make it difficult to inject the proper amount of additive.
Finally, additives can be injected at the loading rack. While this is the most expensive option, it may be the one chosen by most terminal operators. This approach offers the most flexibility and the most efficient use of additives.
An injection system will include the following equipment: a storage tank (double or single wall) that is often skid-mounted, additive pump unit — usually on a skid, and injector measurement and controller sized for flow rate at the injection point.