Chloride (Cl) enters kraft mill chemical recovery cycles in wood chips, caustic, and ClO2 generator spent acid. Chloride concentrations cause recovery boilers plugging and corrosion, minimizing steam generation and causing expensive shutdowns.
For years, pulp mills have purged a portion of precipitator ash to control Cl level. This means that more make-up sodium and sulfur must be added to the liquor cycle when precipitator ash is purged.
Eco-Tec has designed and implemented several systems for the removal of chlorides from the Kraft chemical recovery cycle.
Eco-Tec Precipitator Dust Purification (PDP™) is a Chloride Removal System that selectively removes chlorides from the electrostatic precipitator (ESP) dust. The PDP™ system utilizes Eco-Tec’s patented Salt Separation (SSU) process to achieve the selective removal of chloride from sulphates salts while recovering valuable cooking chemicals (Na, SO4, and CO3).