Minnesota city wants to test wood pellets in coal-fired unit

The Minnesota Pollution Control Agency (MPCA) is taking comment until April 7 on a draft air permit approval that would allow the City of Virginia to modify its facility in St. Louis County to use gas in a biomass-fired unit.

The permit action is a major amendment; therefore, the draft/proposed permit has been placed on public notice. The MPCA is seeking the U.S. Environmental Protection Agency’s (EPA) concurrent review of this draft/proposed permit and the EPA 45-day review period will begin with the 30-day public review period.

This permit action would authorize the city to modify Boiler #11 (emissions unit EU006), a wood-fired boiler, to include a natural gas burner in order to increase its reliability. Currently, EU006 experiences more startups and shutdowns as well as operation at a lower capacity that prevent it from operating on a consistent basis. When EU006 is not operating, or operating at a reduced load, the city fills any steam shortfalls by firing Boiler No. 9 (EU003), a coal‐fired boiler, at a higher rate.

This permit action also authorizes a wood pellet test burn in the coal-fired unit EU003. The main purpose of the test burn is to determine if the pellets are a viable fuel for the existing fuel handling system and combustion chamber. The test burn is limited to 100 tons of wood pellets.

The Virginia Public Utilities Commission is a citizen‐owned utility providing steam and electricity to businesses and residents. The department has the potential to operate any combination of four boilers using coal and/or natural gas and/or wood as fuel. Boiler 7 (EU001) and Boiler 9 (EU003) can burn only coal and Boiler 10 (EU004) is a natural gas-fired boiler. Boiler 11 (EU 006) is a wood-fired boiler to be used for district heating and electric generation. There is an additional boiler, Boiler 8, located at the facility but it is physically disconnected from the Utility System. Pollution control equipment consists of wet scrubbers, baghouses, and/or electrostatic precipitators in combination with good combustion practices.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.