Prior to the adding the Dry-Ex system from Thermal Energy International, Ottawa, the mill was spending millions of dollars to treat and dispose of the sludge as landfill waste.
The system processes 200 wet tons of sludge a day containing 22 percent solids (78 percent moisture), evaporating 5 tons/hr of liquid from the sludge at low temperature. The output was 40 dry tons of biomass dried containing greater than 60 percent solids, which was used as biofuel in a cogeneration process.
According to Thermal Energy, the mill eliminated costly sludge treatment and landfill expenses. It also developed an economical source of bioenergy with reduced emissions. Finally, the papermaker was able to realize a bottom line multi-million dollar swing from waste cost to reduced fossil fuel consumption and energy savings.
