Many of Domtar’s circular economy initiatives have been around longer than that now-popular phrase. These sustainability programs, used across our manufacturing system, have been recognized for improving efficiency and reducing our environmental footprint.
Our Windsor Mill in Quebec was recently featured in a television segment by Radio Canada for its circular economy initiatives. The segment highlighted the mill’s efforts to effectively reuse manufacturing byproducts and forest residue to generate power and to improve soil conditions in surrounding forests.
Benefits of Circular Economy Initiatives
Years ago, we began planting hybrid poplar trees on some of the forestland we own near the Windsor Mill. These forests produce wood for the mill to use to make pulp and paper.
One drawback is that the soil’s acidity in this region can make growing the hybrid poplars difficult. However, the mill has found ways to improve the quality of the soil.
When we harvest trees from the forest, we collect and burn some of the branches and bark to power a co-generation plant at the mill. We sift the resulting ash and return a portion of it, along with some lime sludge and paper biosolids, to the forest, where we spread it on the soil. These treatments reduce the soil’s acidity and improve growing conditions. Today, the trees are growing at a significantly faster rate in the soil that has been treated.
“And what we’ve seen is that there’s so much increased growth, increased nutrient removal — either from trees or understory vegetation — that there’s virtually no nitrogen and phosphorus that manages to migrate to great depths. So everything is taken practically or immobilized in the ground,” says Nicolas Bélanger, professor of science and technology at TELUQ University, in the Radio Canada segment.
Some other manufacturing byproducts from the mill can be used in agriculture, allowing us to reuse nearly 95 percent of the residue we recover. This beneficial reuse of byproducts, one of several circular economy initiatives at the mill, helps reduce the volume of material going to landfill while enriching the soil in nearby forests.
These circular economy initiatives, along with the mill’s performance in other areas, earned the Windsor Mill a Gold Award by the Canada Awards for Excellence in 2021 in the category of Excellence, Innovation and Wellness.