PDP™ Precipitator Dust Purification

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).

Why Use the PDP™ System?

Avoiding build-up and corrosion by reducing the Chloride levels.

For years, pulp mills have purged a portion of precipitator ash to control Cl level, which cause added expense of make-up chemicals required for white liquor. This means that more make-up sodium and sulfur must be added to the liquor cycle when precipitator ash is purged. The PDP™ system offers a more efficient solution.
The installation of an integrated Eco-Tec PDP™ system allows recovery of valuable cooking chemicals (Na, SO₄, and CO₃) while removing chlorides from the ESP dust. The mill benefits by decreasing overall chemical makeup costs and improvements in recovery boiler operation.
The systems are designed to meet each kraft mill’s unique operating requirements and chemical characteristics.

Benefits:

• Significantly less floor and head space.
• Excellent removal efficiency and high chemical recovery.
• Uses Eco-Tec’s highly efficient Salt Separation (SSU^®) process.
• Increased steam and power production, increased boiler capacity.
• No chemicals are required for resin bed regeneration – just water.
• Pre-assembled, skid-mounted, and Easy to integrate into existing processes.
• Reduced downtime for recovery boiler washing, reduced operating and installation costs, reduced shipping costs.
• Complete system design – Eco-Tec systems are highly automated and can often be used to service multiple lines.
• Factory assembled modules and testing in Eco-Tec’s ISO registered facility assures fast start-up and reliable operation.
• Proven, quality, corrosion resistant components and materials selected for long service life in an aluminum processing facility.
• Eco-Tec provides start-up supervision, customer training, and access to the ECO-SERV program that includes performance monitoring and 24 hour telephone service.