Filter plugging in the Colorado Rockies addressed

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In December, multiple media outlets reported problems related to biodiesel use at resort towns in the Colorado Rockies. However, it appears that neither biodiesel nor cold weather were at the crux of it. The verdict is still out on exactly what went wrong-and each case is probably unique-but early indications point to improper fuel blending and perhaps extraneous factors such as elevation.

In late November, the town of Breckenridge, Colo., suspended its use of B20 after running up against "unacceptable levels of filter plugging" in its fleet vehicles. Dan Bell, assistant director of public works for the resort town, told Biodiesel Magazine that the town of Crested Butte, Colo., reported similar problems and, together, they were working to find out what went wrong. Bell solicited the help of researchers at NREL, who were analyzing samples of the fuel, as well as some of the fuel filters that experienced plugging. The fuel did contain cold-flow additives, Bell said.

"Based on what I have observed, I believe this is not a result of cold weather alone," Bell said. "There could be a real story to tell here once we find out exactly what's happening, and why."

Bell does have theories, however, and he said he is certain that the problems in Breckenridge are not related to fuel quality. "I think it's a strange anomaly of some sort," he said, adding that blending techniques could be involved.
Breckenridge's elevation of 9,603 feet might be playing a role in the problem, too. "I have to believe that, because the same fuel is used at lower elevations with no issues," he said. "However, we really need to wait until more work is done on the samples to determine where to go from here. We'll hear from NREL and see where that leads us."

A third resort area in Aspen, Colo., encountered its own problems with B20 in early December. However, the problem had nothing to do with the effectiveness of biodiesel in cold weather and the resort is still using B20, according to Auden Schendler, Aspen Skiing Company's director of environmental affairs.

Aspen Skiing began experiencing plugged fuel filters on a handful of trail-grooming snowcats when temperature dropped well below zero. Schendler blamed the problem on improper blending of B20 in one 30,000-gallon refueling tank. He said that the fuel supplier blended the fuel at the tank instead of the plant. This might have led to an inconsistent fuel mixture, according to Schendler.

"Even some of the mechanics were saying it wasn't the biodiesel," Schendler said. "It was minus 40 on that mountain so even regular diesel engines will have problems. That's what is frustrating for me. We've been using [biodiesel] for three years in extremely cold conditions, and this was the first problem."

Aspen Skiing tested biodiesel the previous two winters at elevations up to 12,000 feet, and this is the first fuel-related problem to arise. Schendler said cold-weather additives are being used.

The company typically uses about 260,000 gallons of B20 on four mountains in one winter season. The biodiesel program costs about $50,000 annually. Aspen Skiing uses biodiesel in 50 snowcats and several back-up diesel generators for electricity-run ski lifts. There have been no further problems with biodiesel since December, Schendler said.
-Staff Report