Clogged Fuel Filters Drive Temporary Biodiesel Suspension

By Ryan Gray | Senior Editor

MINNEAPOLIS - With additional testing necessary to ensure biodiesel blends meet specifications, the state's Department of Commerce on Jan. 12 issued an additional 30-day variance to a requirement for 2 percent biodiesel.

As requested by the Minnesota Biodiesel Council (MBC) and the National Biodiesel Board (NBB), state regulators and biodiesel producers now have until Feb. 10 to clear the existing fuel system and implement stricter quality assurance measures, the state said.

A day earlier, MBC and NBB called on the state to require all biodiesel producers be accredited under "BQ-9000," the industry's voluntary quality assurance program. Biodiesel meeting neither ASTM D 6571 specifications for "Fuel Injection Pump Durability Test with Low Level Biodiesel Blends" nor state specifications for finished alternative fuels could be responsible for clogging fuel filters in cold weather.

A 21-day variance was issued on Dec. 23 with an expiration date of Jan. 13 at noon CST, the second such delay since the law was implemented on Sept. 29.

Legislation passed in 2002 mandating that all diesel fuel sold in the state contain a 2 percent blend of biodiesel produced from the state's soybean crop. It was not implemented until Sept. 29, a month after the Department of Agriculture ensured that state biodiesel producers could meet the mandated annual production capacity of 8 million gallons.

But fleets have since logged "numerous complaints," according to the Department of Commerce, most notably the higher freezing point and the high glycerin level of biodiesel results in fuel gelling.

"Biodiesel is a valuable and renewable part of the state's diesel supply, but it's also important to insure that consumers are receiving a quality product that conforms to the legal requirements for that product," said Deputy Commerce Commissioner Edward Garvey. "That is why this variance (had) been issued."

The Associated Press reported that initial state tests conducted on 18 samples of biodiesel showed four failed a cold-weather test. However, it remained inconclusive as to what specifically caused the failure.

At press time, Shelly Jonas, executive director of the Minnesota School Bus Operators Association, said a biodiesel survey of all school districts and school bus contractors was expected by mid January, following a special meeting of Gov. Tim Pawlenty's office and state Department of Transportation officials.

For the Rochester Public Schools bus fleet the fuel filter clogging problem appeared to be a result of more than just traditional cold-weather gelling. The district located in the southeast corner of the state experienced problems in December with about 10 buses in minus 9-degree weather as a result of a build up that might be attributed to bacteria.

"We actually pulled some of the filters apart and found a sticky black residue resulting in a loss of power or even cutting out the engine altogether," said Jon Goetz, Laidlaw branch manager. The contractor operates 134 routes and transports about 12,000 students each school day for the district, which is the sixth largest in Minnesota.

He added the state and the Petroleum Fuel Marketers Association of Minnesota were running tests on the affected filters to determine the exact cause of the sludge. In the meantime, he said all fuel tanks and storage tanks were "topped off" with a finer blend of No. 1 and No. 2 diesel.

Goetz said he has heard some trucking fleets are using different fuel filters which are more porous and allow the sludge to pass through. But that could lead to further problems down the line, such as failed fuel injectors.

"If we were just hauling trucks it would be different but our cargo is much more precious," he said. "I can't have buses go down with kids on them, especially in extreme weather."

The Minnesota Biodiesel Council and the National Biodiesel Board announced on Jan. 11 a plan for the Minnesota Department of Commerce to increase quality control measures and ensure that only high-grade biodiesel is released into the state's diesel fuel pool. The recommendations filed with Garvey's office include calling for all biodiesel producers to become accredited under "BQ-9000," the industry's voluntary quality assurance program.