Biomass power study begins in Colorado Springs
Colorado Springs Utilities began its year-long biomass power pilot project to determine the best cofiring blend at its Martin Drake Power Plant on Jan. 1.
The plant will consume 50 to 60 tons per day of one inch or less sized woodchips, supplied by Rocky Top Resources. Fort Carson will also provide scrap wood and purchase 2.5 megawatts (MW) of energy to meet its goal of becoming a net zero energy and waste installation. Of the biomass fuel mix, 60 percent is composed of industrial wood waste and 40 percent derived from woody biomass, such as dead juniper trees, said Terry Meikle, energy supply manager at CSU.
Although the project began on Jan. 1, the plant has combusted a biomass blend since Dec. 18 and isaddressing any issues that arise within the system. One issue surrounds a particular pulverizer’s ability to process the biomass, Meikle said. “We’re looking at taking the pulverizer out for inspection and testing the product going to the boiler,” he added. “We think we have a fineness issue with the pulverizer, so we’ll get that taken care of.”
Scrubber bars within the hammer mill at the Drake No. 5 unit made it the ideal choice for the biomass fuel, Meikle says. CSU has tested the biomass in a ball mill pulverizer, but found that it only flattened the biomass and plugged the mill. “Hammer mill pulverizers have scrubber bars that the fibourous biomass can be scrubbed down to a fine enough particle where suspension firing will complete the combustion within two seconds,” Meikle says.
Over the next few months, the utility company will be investigating other technology to make system feeding more efficient.