Fuel and fleet: How they are a-changin'

John Scharffbillig
Fleet Manager
Minnesota Department of Transportation
St. Paul, Minnesota

There are many changes in store for fleet departments in the near future. Some of the biggest issues that we are and/or will be dealing with include:

  • Increasing the use of renewable fuels
  • The rising cost of emission control systems
  • Lack of infrastructure
  • The training of technicians to service these new technologies
  • Availability of components
  • Fuel availability
  • State and federal laws

So the question is, where do we start and what is this going to cost? Can the budget handle this? What are some of the changes?

Let's begin with a discussion about diesel fuels. The next innovation in diesel fuel is the blending with biodiesel. In some areas, this is already happening. Biodiesel is a domestically-produced, renewable fuel manufactured from vegetable oils, animal fats or recycled cooking oils. Biodiesel blends that are currently in use worldwide range from as low as 2% to 100%. The most commonly seen are 2%, 5% and 20% blends, referred to as B2, B5 and B20, respectively.

The production of conventional diesel fuel is through a refining and distillation process from crude petroleum oils. Diesel fuels are on the heavy end of a barrel of crude oil. This gives diesel fuel its high BTU content and power, but also causes problems with diesel vehicle operation in cold weather, when this conventional diesel fuel can gel. The low temperature operability of diesel fuel is commonly characterized by the cloud point, and the cold filter plugging point (CFPP) or the low temperature filterability test (LTFT).

The cold flow properties of diesel fuel vary considerably throughout the year and across geographic regions. In Minnesota, for example, the cold flow temperatures of diesel fuel that are needed to operate without freezing can vary from 25 degrees Fahrenheit in October to -25 degrees Fahrenheit in January and February, while temperatures in Missouri range from 35 degrees Fahrenheit to 5 degrees Fahrenheit, and those in Louisiana range from 40 degrees Fahrenheit to 25 degrees Fahrenheit (October to February).

Thorough testing of the cold flow properties of biodiesel and biodiesel blends has been carried out over the last seven years. Using a variety of diesel fuels, both with and without cold flow enhancing additives, testing was completed by the University of Missouri and analyzed at the Cleveland Technical Center in Kansas City with the results listed below. The data shows that the fuel mixture starts to gel sooner as the concentration of biodiesel is increased.

As the concentration of biodiesel decreases below 20%, the impact on the cold flow properties of the blend becomes indistinguishable from that of the diesel fuel with which it blended. Recent testing of fuel provided by the Agricultural Utilization and Research Institute in Mankato, Minnesota, and performed at System Lab Services, a division of Williams Pipeline, verifies this data.

Will biodiesel work to fuel plow trucks? Here is what they found in Iowa. In most cases, the small increase in the temperature at which B20 starts to cloud, compared to petroleum-based diesel, goes unnoticed and users take no additional precautions. This was the case in Cedar Rapids, Iowa, where Five Seasons Transportation used B20 for over 1.4 million miles of operation in their bus fleet during one of the coldest winters on record (temperatures were below -20 degrees Fahrenheit for almost a week). They made no changes to their operation, other than to incorporate 20% biodiesel into their existing diesel fuel. Mr. Bill Hoekstra of Five Seasons wrote: "As you well know, this demonstration started out during the coldest winter we have had in years. Even with this obstacle, the program continued without any particular problem showing up that could be attributed to biodiesel."

From everything read, biodiesel shows some real promise for a renewable fuel source that will work in most conditions, as well as meeting environmental concerns.

Now let's take a look at the road ahead. This has been coming for a long time: In 2007 everyone, nationwide, will be required to burn "Ultra Low Sulfur Diesel Fuel." The Environmental Protection Agency (EPA) regulations will require refiners to begin producing ultra low sulfur diesel fuel starting June 1, 2006. Beginning September 1, 2006, ultra low sulfur diesel fuel must go on sale nationally. The regulated diesel emissions will address particulate patter (PM), carbon from incomplete combustion, soluble organic fractions from the fuel and lubricating oil (SOF), sulfates formed from the sulfur in the fuel, oxides of nitrogen (NOX) composed of nitric oxide (NO) and nitrogen dioxide (NO2), hydrocarbons (HC) regulated either as total hydrocarbon emissions (THC) or as non-methane hydrocarbons (NMHC), and carbon monoxide (CO). Also regulated will be smoke/opacity, which contribute to acid rain, ground-level ozone and reduced visibility.

So what does that mean for diesel-powered fleets? There are several strategies in various stages of implementation to make existing diesel engines cleaner. In addition to efforts to optimize fuel delivery and air intake systems, after-treatment devices such as particulate traps and catalytic converters, offer ways to prevent emissions from entering the air. Particulate traps collect and burn away particulate emissions. Catalysts convert damaging pollutants to less-harmful by-products. There are also efforts to improve the emission characteristics of diesel fuel by modifying fuel properties such as sulfur content and the use of fuel additives.

This makes us all consider how we will manage our fleet departments with the onslaught of changes. With fuel being the second-highest cost associated with managing a fleet we need to take a good, hard look at what changes we need to make, what training will be needed for the technicians, and how we obtain and store the products.

What will be the increased costs, and can the budget handle them? It is difficult to calculate with any accuracy just what the associated costs with these fuel initiatives will be. The one thing we know for certain, they are going up.

John Scharffbillig can be reached at (612) 725-2354 or john.scharffbillig@dot.state.mn.us.

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