Maintenance/Management: An interesting blend

It sure sounds like a good idea: Reduce our dependence on foreign oil supplies while making the air cleaner to boot.

And for those reasons a lot of government agencies are falling in love with biodiesel.

As of September 2006, the National Biodiesel Board has tracked more than 275 pieces of biodiesel-related legislation at the state level. The Department of Energy lists 22 national laws and 289 state laws and incentives for biodiesel on their Alternative Fuels Data Center.

But this regulatory lovefest notwithstanding, the jury is still out on how well biodiesel performs compared to “petrodiesel.” Supplies are sometimes spotty, the fuel quality varies and if you use it, you’re going to have to change your maintenance procedures.

What the companies say
Individual manufacturers are expressing cautious approval for the use of biodiesel; some are more enthusiastic than others.

The Engine Manufacturers Association’s technical director Roger Gault says his association’s members have different levels of interest in biodiesel. “Everybody recognizes the strong desire for biodiesel to be a viable choice, but when people make that choice they want to be sure they aren’t giving up performance and reliability,” Gault says. “There is some confusion right now, mostly due to a lack of information.”

Some manufacturers are jumping on the biodiesel bandwagon. One example is Case Construction Equipment. “In mid-2006, Case became the first construction equipment manufacturer to approve the use of B5 blends in all of its Case-manufactured mechanically governed engines,” says Gary Stanek, manager of engine applications and planning. “The use of B20 blends is possible with all Case engines other than electronic engines and those in the Case 410 and 420 skid steer loaders,” Stanek says.

Deere has also taken a positive approach to biofuels. “Deere is supportive of the alternative fuel initiatives,” says Tom Withers, Deere’s marketing communications manager. “We have approved B5, and virtually all of the Deere manufactured engines leave our plants with a factory fill of B2.”

A few companies are a tad more conservative in their approach. Volvo’s Bendj Johansson says, “At the moment, we fully support the use of B5 in all Volvo CE machinery. Biodiesel is a good short-term way to reduce carbon dioxide emissions. We are doing tests to find out if we can support higher blends and our ambition is to fully support B30.”

Caterpillar neither approves nor prohibits the use of biodiesel in its machines. Kris Stearns, senior associate engineer for fluid products, says, “Biodiesel that meets the requirements listed in the Caterpillar Specification for Biodiesel is acceptable.”

Coming to terms
Part of the confusion Gault describes is due to the lack of mandatory standards for the biodiesel industry. Even the word “biodiesel” is ambiguous.

In an effort to create industry quality standards for biodiesel blends, the National Biodiesel Accreditation Program offers a voluntary quality assurance program to certify producers, distributors and marketers. The program has two categories – accredited producer and accredited marketer. Wholesale distributors and retailers who meet the NBB’s programs are designated BQ 9000. A listing of BQ 9000 suppliers is at this site.

The EMA supports up to B5 biodiesel blends provided the blends meet the ASTM D-6751 standards for biodiesel and the ASTM D975 standard for petrodiesel. The EMA recently developed test specifications for fuels B5 to B20.

Only biodiesel and biodiesel blends that meet ASTM D-6751 are recognized by the NBB. Most engine manufacturers have adopted D-6751 and warn that using other “bio-derived” materials that do not meet D-6751 in their engines may cause engine and fuel system problems.

The OEMs are quick to note the importance of these fuel standards and their impact on engine performance. Withers says equipment owners need to identify and buy only from biodiesel producers and distributors who follow the proper blending procedures and who are BQ-9000 accredited.

Light green
Last year, more than 150 million gallons of biodiesel were sold in the United States, doubling the amount sold in 2005. Still, biodiesel has to overcome some big challenges.

The first challenge is availability and distribution. “The production, quality, and necessary infrastructure is not currently available at a level that would allow biodiesel to be a competitive commercial product nationwide when compared to diesel fuel,” Stearns says.

The biodiesel industry is rapidly trying to overcome distribution problems. Eighty-seven plants are currently producing biodiesel and 65 more are under construction. But until distribution channels become more widespread, biodiesel could remain a regional choice.

Performance and price
According to the NBB, biodiesel shows similar fuel consumption, horsepower, torque and haulage rates as conventional diesel fuel. The DOE states the energy content in biodiesel is about 10 percent less than diesel No. 2 and about the same as diesel No. 1. In theory, adding biodiesel to diesel No. 2 should reduce power, torque, and fuel economy. In actual applications, DOE says low-level biodiesel blends perform as well as conventional diesel.

With the rising costs of diesel fuel in 2005, the cost of biodiesel blends is comparable to No. 2 diesel, says the DOE. The price per gallon for biodiesel is comparable to the price petrodiesel on a regional basis. Nationally, however, biodiesel can be as much as 20 cents higher than regular diesel. The June 2006 U.S. Department of Energy Clean Cities Alternative Fuel Report listed the national average cost of a gallon of diesel at $2.98, and a gallon of B20 at $2.92.

“The science says a contractor would use the same number of gallons of biodiesel as he would have used if he had been burning diesel,” says Jenna Higgins at NBB. “Anecdotal evidence is some users report getting better fuel economy with biodiesel.”

But Stefan Salomonsson at Volvo says fuel economy is going to depend heavily on the percentage of the blend. “When using B5, there is not a significant difference,” Salomonsson says. “But, if B30 is used, you might see a 5 percent increase in fuel consumption compared to regular diesel.”

Biodiesel handling and maintenance tips
Case provides these recommendations for biodiesel storage and handling.

  • When switching over to biodiesel, change the fuel filters once or twice between regularly scheduled filter changes. More frequent filter changes will catch residue left by regular diesel in engines and fuel injectors. Biodiesel can also remove rust and particles from the inside of on-site fuel storage tanks and vehicle fuel tanks that would normally adhere to the sides of the tank and not cause any problems. Particles trapped by the vehicle fuel filter can shorten filter life and cause filter blockages. Complete cleaning of the entire fuel-handling system and storage tanks may be required in some instances.
  • When handling the fuel, take care not to allow water to get into the supply. Keep fuel tanks as full as possible to limit the amount of air and water vapors.
  • Drain water drains on engine-mounted fuel filters at least once a week.
  • Check the engine oil dipstick daily to ensure that the level is within the normal high and low operating range.
  • Due to potential stability problems with biodiesel, the fuel should not be stored in on-site storage tanks for more than three months. Biodiesel fuel blends stored longer than three months should not be used as fuel for a diesel engine.
  • Machines should not be stored for more than three months with biodiesel blends in the fuel system. If longer storage periods are necessary, the engine should be run on pure diesel fuel for 20 to 30 minutes to flush the biodiesel fuel out of the engine fuel system prior to storage.
  • In cold weather, how well biodiesel runs in the cold depends on the percentage of diesel in the fuel blend. B2 may have fewer problems than B20. Start with the absolute best winterized generic fuel with a cold flow improver additive and kerosene if necessary in
  • Be mindful of where fuel is stored. Fuel stored below ground can maintain temperatures around 40 degrees in winter, but fuel stored above ground will cool to air temperature. Tanks exposed to cold conditions should be equipped with heating elements, insulation and tank mixers.

Biodiesel fuel blends are designated by the letter “B” followed by a number that designates what percentage of the fuel is derived from agricultural sources (most often soybeans). So B5 will be a blend of 95 percent petrodiesel and 5 percent bio-oils. B20 is 80 percent petrodiesel and 20 percent bio-oils.