Скачать или смотреть Digitalization and Optimization of Chemical Recovery at Suzano’s Imperatriz Unit

How ANDRITZ and Suzano reduced ATT variability in green liquor and stabilized the bleaching process using data and advanced control.

Previously, ATT was adjusted based on density, which led to high variability and reduced causticizing efficiency. The team analyzed more than 70 variables, created a virtual sensor with over 80% accuracy in the Digital Twin, and implemented four advanced controls: ATT of raw green liquor, ATT of filtered liquor, temperature, and lime dosage. They monitored nine loops in the CPA, tuned loops, added alarms in the DCS, and trained operators.

Key operational results:

Effective alkali increased from 116 g/l to 122 g/l;
Reduction of dead load by 6 to 7 kg per ton of pulp;
Annual savings estimated at R$ 600,000 to R$ 970,000;
Over 60% reduction in over and under line;
45% reduction in ATT standard deviation;
Production stabilization up to 94%;
Washer stopped shutting down after control implementation; unplanned stops were reduced to almost zero.

This project demonstrates how advanced control, virtual sensors, and joint field action deliver predictability, efficiency, and uptime for the plant. Watch and see the steps—from analysis to execution—that ensured fiber line stability.