Burns & McDonnell to develop biomass gasification power plant for Xcel

In late 2009, Xcel Energy received approval from the Public Service Commission of Wisconsin to convert the last of three coal-fired generating units at the plant to biomass gasification. Two of the units already produce electricity by burning lower quality, unused wood left behind in logging operations in forests. Upon conversion, the third unit will burn similar wood waste material in a process in which the fuel reacts with a combination of air, high temperatures, and pressure to create synthetic gas (syngas). The syngas will then be used to fire the boiler, the company said. As part of its contract with Xcel, Burns & McDonnell will review and finalize project costs. Project activities will include design and construction of additional biomass receiving and handling facilities, technology assessment, purchase and installation of gasification equipment, engineering design and installation of equipment needed to modify the third unit boiler and engineering design and construction support for installation of air quality control equipment. Engineering design and technology evaluation is already underway and construction is scheduled to commence in 2011. The project is scheduled to be in operation in 2012. Once the coal-to-biomass conversion is complete, nitrogen oxide (NOx) emissions will decline by 60%, sulfur dioxide (SO2) emissions will decline by 80% and particulate matter will decline by 80%. In addition, net carbon dioxide emissions are expected to be reduced due to sustainable harvesting practices employed in gathering and utilizing biomass fuel and by utilizing substantially cleaner syngas to fire boilers.