Truck Topics
Biodiesel: The alternative fuel of choice?
The recent upward surge in diesel prices coupled with the temporary fuel shortages due to the Katrina hurricane once again focused the nation's attention on our fragile energy infrastructure.
The storm disabled a number of offshore drilling platforms, pipelines were shut down and the diesel pumps at some truck stops went dry (briefly).
Once again, motorists' and truck drivers' thoughts turned to alternative fuels and particularly, biodiesel.
This renewable energy source has been touted for the last few years as one of the most promising of the alternative fuels available, but it's been slow in gaining widespread acceptance.
What is Biodiesel?
Let's get the definition from a reliable source, the National Biodiesel Board, a manufacturers’ association:
Biodiesel is not straight vegetable oil. It is made when oils or fats, usually waste from a restaurant or other source, are passed through a process called transesterification, which creates two chemicals: diesel fuel and glycerin, which is used to make soap.
The fuel must meet an industry specification, ASTM D6751, and must be “biodegradable, nontoxic and essentially free of sulfur and aromatics,†the Biodiesel Board said. Biodiesel can be used alone to fuel a diesel engine, or it can be blended with traditional diesel fuels.
The most popular type of biodiesel now used is B20 (a blend of 20 percent by volume biodiesel with 80 percent by volume petroleum diesel). It’s also used in a 2 percent blend with diesel, primarily for added lubricity.
Biodiesel has about 90 to 95 percent of the energy content found in No. 2 diesel but contains no aromatics or sulfur. It has a high cetane number (related to ignition capabilities) and offers good lubricating qualities.
It reduces carbon monoxide, sulfur dioxide and particulate emissions by significant amounts but may produce higher levels of NOx (oxides of nitrogen) emissions. Since it is sulfur-free, biodiesel can be used with aftertreatment devices that require low-sulfur fuel.
Biodiesel, with a flash point of 150 °C, is not as readily ignited as petroleum diesel (64 °C) and far less so than the explosively combustible gasoline (-45 °C). Indeed, it is classified as a non-flammable liquid by the OSHA, although it will of course burn if heated to a high enough temperature. This property makes a vehicle fueled by pure biodiesel far safer in an accident.
That all sounds very promising, so what's the downside?
Well, the fuel is sensitive to cold weather and has a higher cloud point than petro-diesel fuel. Biodiesel that is likely to gel and stop a truck dead on the side of the road is unlikely to gain a large trucker following. So, it requires anti-freezing treatments like conventional diesel fuel and that costs money.
Most sources say that Biodiesel can be operated in any diesel engine with little or no modification to the engine or the fuel system. However, Biodiesel has a solvent effect that may release deposits accumulated on tank walls and pipes from previous diesel fuel storage.
"The release of deposits may clog filters initially and precautions should be taken."
Which means that gunk can plug and block fuel lines and filters, at least when the Biodiesel is first used. And, as one veteran driver points out, "let's say you've been using Biodiesel for awhile, and your lines and fuel filters are clean and all that, but you get out where you can't find Biodiesel. So, you have to run a few tanks of conventional diesel fuel. When you start burning Biodiesel again, do you start the cleaning process all over?"
Since it acts like a solvent, it may pose problems for seals and other rubber components in pre-1994 engines, according to the Biodiesel proponents.
And, now for the big question. will it save you money?
Currently, biodiesel is generally somewhat more expensive to produce than petroleum diesel, which is often stated as the primary factor keeping it from being in more widespread usage. Economies of scale in biodiesel production, however, as well as the rising cost of petroleum, may reduce, eliminate, or even reverse this cost differential in the future.
Current worldwide production of vegetable oil and animal fat, however, is not enough to replace liquid fossil fuel use. Some environmental groups, notably the NRDC (Natural Resources Defense Council), object to the vast amount of farming and the resulting over-fertilization, pesticide use, and land use conversion that would be needed to produce the additional vegetable oil.
There seems to be little argument that Biodiesel is better for the environment because it is made from renewable resources and has lower emissions compared to petroleum diesel. It is less toxic than table salt and biodegrades as fast as sugar. Since it is made in the USA from renewable resources such as soybeans, its use decreases our dependence on foreign oil and contributes to our own economy.
Where can I purchase biodiesel?
Ah, there's the rub. The Biodiesel advocates say that the fuel can be made available anywhere in the US, and the National Biodiesel Board (NBB) maintains a list of registered fuel marketers, but that doesn't mean it's going to be found everywhere anytime soon. A current list is available on the biodiesel web site at www.biodiesel.org or by calling the NBB at (800) 841-5849.
Is it approved for use in the US and is anyone buying it?
Biodiesel is registered as a fuel and fuel additive with the Environmental Protection Agency (EPA) and meets clean diesel standards established by the California Air Resources Board (CARB). Neat (100 percent) biodiesel has been designated as an alternative fuel by the Department of Energy (DOE) and the US Department of Transportation (DOT).
The National Biodiesel Board has released the following sales volume estimates for the US:
2004 -- 25 million gallons
2003 -- 20 million gallons
2002 -- 15 million gallons
2001 -- 5 million gallons
2000 -- 2 million gallons
1999 -- 500,000 gallons