Biomass pile fire causes little damage

By Lisa Gibson
Posted July 7, 2009, at 1:30 p.m. CST

A fire on a six-acre hog fuel pile on July 4 at the Biomass One power plant in White City, Ore., caused only minimal damage, but high winds during the fire did cause some concerns.

The damage is hard to quantify on such a large pile, according to plant general manager John Bremerman, but was confined to just one side and didn't spread to the rest of the pile. "There was not a tremendous amount lost," he said. High temperatures, humidity in the teens and high winds probably contributed to the blaze, he said, but hog fuel pile fires often look worse than they are. "The embers blow around in the wind," he said. "The thing that rattled everyone was the high winds. [The fire] didn't do much, but it was impressive, I'm sure." Firefighters responded quickly and left the scene within a couple hours, he said. The fire also burned a nearby grassy area about 100 by 100 feet, Bremerman added.

The official cause of the fire on the 80-foot-high pile is unknown, but Bremerman speculates spontaneous combustion is the culprit. Hot spots are common in large piles and can be smothered easily. The problem usually is on the edges of the pile, he said. If the loose sluff is not compacted, it allows air movement. Biomass One usually removes that sluff, but didn't have room over the weekend, as it was not operating to allow for maintenance. The company has an inventory of about 113,000 dry tons, according to Bremerman.

The last large hog fuel fire at Biomass One was in 1995 and consumed an entire pile, he said. It also damaged a neighboring custom drying molding mill, which ceased operations in 1997. "Big ones aren't common," Bremerman said.

The 30-megawatt wood fire power plant provides electricity to PacifiCorp, Portland, and employs 65 full-time jobs. Feedstocks include slash, segregated wood from seven area landfills, sawmill residue, wood chips, land clearing residue, tops, limbs, trimmings and urban wood waste, among others. The pile that caught fire consisted of three-inch minus standard hog fuel, according to Bremerman.