Earlier this year, the town of Breckenridge, Co. discontinued using its B20 blend in its fleet vehicles after the biodiesel fuel began gelling at cold temperatures, bringing vehicles to a halt. The Breckenridge-based Aspen Ski Company also curtailed its use of B20 in its backup generators for chairlifts for the same reason.

The Park Record reports, however, on the success of B20 at a local Park City resort.

Two weeks ago, Neuhauser began running one of his cats on what's known as B-20 Blend: 20 percent bio-diesel, and 80 percent petroleum diesel... Someday soon, if all goes well with this year's guinea pig, Neuhauser hopes to run an entire fleet of bio-cats at The Canyons.

In an interview with The Park Record, Auden Schendler, director of environmental affairs at Aspen Ski Company, said the [gelling] issue had to do with the blending, not the use of bio-diesel fuel.

“Any diesel blend—and that’s what cats have always used, a blend—can gel in cold weather,” explains Schendler. “You have to make sure the blend is correct which is usually a blend of No. 1 and No. 2 diesel and you have to use additives. When we make Biodiesel part of the mix, those concerns [of gelling] don’t get any worse, but they remain. Diesel always has a gelling problem in the cold. It’s just that bio-diesel sort of adds a boogie-man factor people don’t understand.“

Gasolines have freezing points well below even the most severe winter conditions. Petroleum diesel fuels, however,  have both pour points and cloud points (the temperature at which a cloud or haze of wax crystals first appears and separates from the fuel) well within the range of cold temperatures at which they might be used.

Biodiesel has the same issues, but at even higher temperatures. The cloud point for biodiesel will vary based on the type of feedstock used.

To guard against diesel clouding and gelling, refiners change blending formulas between summer and winter, working from an ASTM specification for fuel composition based on seasons and latitudes, and use additives. The same can be done with biodiesel, as noted above. You just need to get it right.

Some manufacturers are beginning to offer cold-weather additives specifically targeted at biodiesel. Amalgamated, Inc., a custom blender of additives, for example,  is offering what it calls USA B-20 Winterizer Ultra Soy Additive. The company asserts that the additive improves  the cold temperature fuel flow ability down to -30° F in all biodiesel blends without the use of #1 diesel.