Evaporator flushing creates significant water savings and energy efficiency at Cloquet Mill

Sappi’s Thrive25 sustainability goal seeks to reduce total specific energy use by 1% annually for five years. The Cloquet project resulted in saving over 2 million gallons of water and 3.2 million pounds of steam. It also increased production through increased black liquor firing, all of which exceeded the 1%-a-year energy reduction goal.

The Cloquet Mill initiated a Rapid Lean Six Sigma energy project to target TUBEL super-concentrator evaporator flush reduction. The goal was to reduce the flush water volume by 25%, ultimately reducing the amount of energy needed to reprocess the flush water by 25%. The team reevaluated flushing techniques, triggers, durations, and sources of water. Ultimately, the project established new flushing operational parameters, implemented best practices for flushing duration, and achieved over double the initially planned savings.

Sappi is realising eco-effective achievements across our global business with projects involving capital investments, operational efficiency improvements and targeted continuous improvement projects.