Diesel Fuel - Costs, Safety and Concerns
By BRETT WINBERG - LubeTrak

Clean fuels production is a worldwide initiative with some regions ahead of the United States 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 U.S.A. regulations. Several options exist for the refiner to produce ULSD.

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 problems were linked to severely hydro treated jet fuels having both low sulphur and low aromatics contents. Sulphur is the main factor of lubrication in today’s diesel fuels and with tighter guidelines and pressures within the fuel system… these will create component failures in many applications that are using newly designed diesel 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.

When you take out the sulfur, you also take out lubricity and reduce antioxidancy and other valuable properties — not well for a diesel engine. The likely result: wear leading to failed injectors. And that translates into breakdowns and repair expenses. What is the standard needed from most OEM’s to determine if fuel is safe to use? This is a good question. Most OEM’s require that diesel fuels be tested using the ASTM D6078 method for lubricity and that the results be greater than 3100 PSI. Most low sulfur diesel fuels run an average of 2850 psi to 2900 psi, so some sort of additive would be required to meet OEM specification.

In diesel fuel systems, the fuel provides lubrication for the fuel pump and injectors. A fuel with poor lubricity can cause excessive wear and premature failure of these components. With reductions in fuel sulfur level, lubricity is becoming a larger concern. Many refiners are using lubricity-improver additives to restore the lubricating properties of the fuel.

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.

There are many fuel additives on the market that say they increase lubricity and help lubricate all the components of the fuel system, however, don’t be too easily swayed. 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. We recommend asking for the manufacture testing of the additive and to make sure 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.

With new standards of fuel systems, we also recommend that you are using a premium fuel filter. Newer and tighter clearances require cleaner fuels with lower micron filters. The price of new injectors has risen over the years because of technology and most injector’s start out at $325.00 each and go up from there. So assure your filters are of high quality and when possible, run a water separator filter to guarantee the cleanest fuel possible. Also, get your fuel tested today… it could mean significant savings down the road.

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