NorskeCanada mill uses coal as auxiliary fuel to improve wood waste boiler performance

NorskeCanada's Elk Falls mill is an integrated printing papers, kraft, and containerboard operation located in Campbell River, BC, on the East Coast of Vancouver Island. Production facilities include a 1,100-mtpd kraft mill, a 1,600-mtpd thermomechanical pulp mill, three paper machines, a market pulp drier, and a containerboard machine. The No 5 power boiler, a large hog fuel boiler, burns wood waste along with a small amount of natural gas or Bunker C fuel oil. This Babcock & Wilcox boiler produces 50.5 kg/sec (400,000 lb/hr) of 4,140 KPa (600 psig) steam. As a result of the boiler's unique design, optimal hog burning is difficult to achieve. Unstable furnace air conditions are prevalent, as the lower hog combustion zone below the boiler arches competes for oxygen with the fossil fuel combustion zone above the arches. A recent retrofit to this boiler was a wet electrostatic precipitator. Built in 2001, this precipitator allows Elk Falls to achieve significantly lower paniculate emissions levels while burning salt-laden coastal hog fuel.