An air emissions control project on Unit 4 of the coal-fired Boswell Energy Center is about 66% complete as of April 30 and is tracking for completion around the end of this year, said a quarterly update filed May 28 at the Public Service Commission of Wisconsin by unit co-owner WPPI Energy.
The commission had in February 2013 approved WPPI’s share of project expenses. The status of construction at this Minnesota plant is:
- Installation of the NID penthouse roof has been completed
- Erection of NID reactor compartments has been substantially completed
- Installation of various NID equipment has been substantially completed
- Prefabrication and erection of NID inlet and outlet ductwork is in progress
- Installation of process piping is in progress
- Installation of NID building siding is in progress
- Pulling and termination of cables is in progress
The unit owners (Minnesota Power and WPPI) are installing Alstom’s circulating dry scrubber (CDS) technology, referred to as the NID system, for the removal of particulate matter (PM), SO2, acid gases including hydrochloric acid and trace metals, and other hazardous air pollutants being addressed by EPA regulations, while also reducing plant wastewater. In addition to the NID system, they are also installing a powdered activated carbon (PAC) system to capture flue gas mercury, in combination with the fabric filter integral to the NID to control PM.
The project will bring the 585-MW Boswell Unit 4 into compliance with state and federal regulations. WPPI Energy owns 20% of Boswell 4.