UNDERWOOD, N.D., Jan. 16, 2002 — Great River Energy, The Falkirk Mining Company and The Coteau Properties Company have successfully completed phase one of a three-phase lignite moisture reduction project.
This research project was conducted to increase the quality and value of North Dakota lignite by economically reducing moisture content.
Lignite test burns were done at Great River Energy’s Coal Creek Station generation facility near Underwood in August and October 2001, showing promising results for the lignite industry. Approximately 16,500 tons of lignite was used in the two tests.
According to Great River Energy’s engineering leader at Coal Creek Station, Charlie Bullinger, North Dakota lignite averages 38 percent moisture content, which requires a drying process within the pulverizer system before entering the boiler. High moisture reduces boiler efficiency and increases corrosion on crucial equipment. The drying process developed for this research project was able to reduce the moisture content by 25 percent.
“By drying the lignite before it ever enters the plant system we were able to see a number of improvements in various areas,” Bullinger said. “Boiler efficiency increased by 2 percent, horsepower requirements for fans and pulverizers were significantly reduced and strong reductions were shown in emissions, specifically with nitrogen oxide (NOx) and sulfur dioxide (SO2).”
“The goal of the research was to develop a process that uses waste heat from power production to reduce the amount of moisture in lignite before it is burned in a boiler,” said The Falkirk Mining Company’s staff geologist, Dennis James. “By reducing moisture we have successfully shown efficiency improvements at Coal Creek Station.”
James said these improvements mean that more electricity can be generated with the same amount of coal. At the same time electricity needs within the power plant is reduced, increasing electricity available to customers.
Bullinger said phase two will include doing a large scale pilot study and phase three of the research project would be full-scale drying operations at Coal Creek Station.
“We are all very pleased with these results and the potential for the lignite industry as a whole,” Bullinger said. “There could be substantial new uses for North Dakota lignite in out of state markets, because drying lignite in this manner makes the coal more competitive.”
“This is another example that shows the effectiveness of the state and industry partnership in the research and development program for lignite,” said John Dwyer, chairman and acting technical advisor for the Lignite Research Council.
This research was funded by Great River Energy, The Falkirk Mining Company, The Coteau Properties Company and a $161,000 grant from the North Dakota Industrial Commission.
Great River Energy is a generation and transmission cooperative based in Elk River, MN serving 29 distribution cooperative members. The Falkirk Mining Company and The Coteau Properties Company are wholly owned subsidiaries of The North American Coal Corporation of Dallas, TX.