Becoming more eco-effective in North America

With innovation and ingenuity, we are making our mills eco-effective—reducing waste, emissions and maximising material and resource use at every opportunity. 

The most innovative eco-effective solutions in North America often emerge from Lean Six Sigma (LSS) projects. With innovation and ingenuity, these projects reduce waste and maximise material and resource use for people, planet and our shared prosperity.

At our mill in Cloquet, a team led by Ben Boyum, a Process Engineer, identified an opportunity to not just reduce waste sent to landfill but also the need to buy more raw materials.

In the kraft pulping process, there is a recovery procedure to convert chemicals back to their original form for reuse. The Cloquet recovery process utilises a drum filter for filtering green liquor and process particulates known as dregs. The filtering process requires a layer of lime mud on the filter media as a pre-coat to allow the dregs to separate from the green liquor. With each revolution of the drum, this pre-coat is scraped away until it is all used, then the filter is recoated with lime mud.

The goal of the project was to significantly reduce the amount of lime mud used for pre-coats by increasing the amount of time between recoating the filter with lime mud while still maintaining the quality of the green liquor. The project was a great success, resulting in approximately 1,600 fewer tons of lime mud wasted each month that would likely have gone to landfill. 

To put this in perspective, this is a savings of over 65 fully loaded semitrailers of material each month! Equally important, by keeping the lime mud in the system longer, there is less need to purchase new raw materials.

This project was a triple eco-effective win for Sappi - we reduced waste, saved money and developed a new LSS Green Belt team leader in Ben Boyum.