The recovery boilers of pulp mills typically have electrostatic precipitators for cleaning flue gases that were installed when the boiler was built. These precipitators have often worked for as long as several decades. The old precipitator technology might well have been left behind the current standards during that time. This can also be an obstacle for developing efficient pulp production.
The electrostatic precipitator recovers the fly ash and the pulp boiling chemicals that leave the boiler with the flue gases and then they are recycled back to the pulp process. The more efficient the recovery boiler’s electrostatic precipitator is, the more closed the resulting process is. Both the environment and the forest company benefit from this.