New Diesel Fuels, New Challenges
By Brett Winberg

Production of ultra low sulphur diesel (ULSD) has been in effect since the 1st part of May 2006 in parts of the United States . Refiners have many plans to produce ULSD, which vary in complexity from plant to plant. Using their tailored methods, each refinery will provide a portion of the total ULSD demand within the U.S. markets.

However, some refiners are still concerned with their ability to deliver the product because of the vast majority of issues involved in producing this product. These concerns range from the method of production to the pipeline transportation system. Other countries have initiated ULSD production and have experienced startup, operational and production problems in the past.

Clean fuels production is a worldwide initiative with some regions ahead of the USA in implementation, and still others are behind U.S. initiatives. The worldwide refining community recognizes the key role clean fuels play in the improvement of the environment. The refining industry has successfully faced many such challenges by delivering continually cleaner, low cost transportation fuels to the consuming public.

The “clean fuels” title is used to cover a wide range of fuel characterizations for different initiatives: reduce sulphur levels, add oxygenates, reduce aromatics, increase octane or cetane and meet additive package requirements. Selected from this wide-ranging criterion are the specific issues and factors surrounding the refinery requirements to produce 100% highway ULSD according to USA regulations. Several options exist for the refiner to produce ULSD. Selecting the best option involves carefully weighing many important issues:

The refiner’s goal is to produce an ULSD that not only meets the regulatory requirements of 15ppm sulphur, but also the additional commercial requirements of a high quality product. High severity hydro treating is known to produce color-unstable products. A variety of reasons are given for the occurrences of poor product color stability, but one common factor is the reactor outlet temperature.

Lubricity (or boundary lubricity) has been defined as “a liquid's intrinsic ability to prevent wear on contacting solid surfaces in the absence of any hydrodynamic lubricating films”. With only 15-ppm sulphur in our future, this may mean more downtime issues within your fuel system. This property has been a concern due to problems experienced with accelerated jet engine failures for low sulphur jet fuels.

The ASTM standard for diesel fuel, ASTM D-975 is being modified to include a specification on diesel fuel lubricity. Lubricity is determined in the fuel quality to prevent or minimizes wear in a diesel fuel system from trucks, busses and stationary equipment. Trace levels of naturally occurring polar compounds which form a protective layer on metal surfaces with in the fuel system largely provide Diesel lubricity.

A refinery hydro treating processes, which reduces the sulfur content of a diesel fuel blend, can also remove these polar compounds. As a result, most of the diesels produced by refineries to meet January 1, 2006 ultra-low sulfur diesel (ULSD) sulfur specifications will not have adequate lubricating properties to meet the new ASTM lubricity specification.

Fuel Additives to Increase Lubricity
In 2004, some major U.S. finished fuel common carrier pipeline companies… announced that they would not allow the transport of diesel fuels already treated with lubricity improvers. This is due to their concerns about “trail back” of the lubricity additive into jet fuel tenders following the additive diesel, which are not allowed to contain these additives. As a result, most lubricity additive usage in the U.S. will take place at fuel terminals.

What To Do...
There are many fuel additives on the market that say they increase lubricity and help lubricate all the components of the fuel system, but don’t be fooled. Most fuel additives are made up of the same five constituents of diesel fuel, which in the end, really do not change any values of the diesel fuel.

Find out the testing method that the fuel additive manufacture is using. Assure they have tested their product using the ASTM D-6078 standard. This will give you and your equipment the assurance that improved lubricity can be achieved and that your diesel fuel is helping protect the fuel system components.

The future of your fuel system is on your hands, be smart and choose the right product for your application. For more info on fuel treatments, feel free to drop us an email with questions you may have.

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