1. Controlling Emissions from Wood Boilers

Currently, the use of emission controls on wood boilers is limited and has seen incremental forward movement, as compared with the advances used in Europe. The use of advanced boiler designs, as well as, the use of emission control devices such as ESPs and baghouses are commonly deployed in Europe on small wood boilers (units 1 million Btus and larger). However, in the United States the use of advanced emission controls devices is rare, and has generally been limited to the use of fabric filters. The lack of progress and market penetration for the development of control strategies can, in part, be attributed to the small market for controls for these systems, and the fact that, on the basis of a unit’s size and annual output most units do not trigger state permitting thresholds for evaluating and applying LAER (Lowest Achievable Emission Rate) or BACT (Best Available Control Technology, notwithstanding the potential air quality and public health impacts from these boilers. The following attributes can influence emissions unit performance: