The Domtar K-Lime project epitomizes the practical application of technology to improve sustainability across environmental, economic, and social dimensions. Taking materials that were being sent to the landfill and finding some sort of beneficial use for them is such a great example of sustainable innovation.
Domtar designs, manufactures, markets and distributes pulp, paper, and personal care products. The company’s mill in Plymouth, North Carolina, implemented a project to reduce waste to landfill by more than 90% and create a new product for the local agricultural community.
The pulp and paper making process generates significant amounts of manufacturing waste, including boiler ash, causticizing residuals, and wastewater treatment residuals. These waste streams are typically managed separately, and can have individual characteristics such as high pH that make them difficult to handle and reuse, Domtar says.
Domtar has a goal to reduce total waste to landfill from its pulp and paper mills 40% by 2020 from 2013 levels. The company’s Plymouth mill recognized the potential value of several of their individual manufacturing byproducts. In partnership with North Carolina State University’s local agricultural research station and affiliated consultants, the mill conducted extensive laboratory and field studies to find the optimal blend of residual byproducts for improving local agricultural soils and crops.
The mill experimented with different blends of what have always been seen as wastes until they discovered the optimal quantities to balance out the extreme properties of each byproduct. They developed Plymouth K-Lime, an effective, lower-cost alternative to conventional fertilizer, according to Domtar. Plymouth K-Lime, which is now registered with the North Carolina Department of Agriculture, was named after two nutrients needed for crop growth: potassium, which has the chemical symbol K, and lime. Domtar sells K-Lime to local farmers, and the company says that the product saves them approximately $35 per acre over conventional fertilizers. Demand is so great that the product is sold out for the next 6 to 9 months.
The project helped the Plymouth mill reduce landfill operating expenses by approximately $150,000 per year and avoid future capital expenses to construct new landfill cells of about $3 million every five years, Domtar says. It also contributes to environmental improvements by nearly eliminating manufacturing waste sent to landfill from the mill. Landfill operations went from five days a week to one and the project eliminates nearly 190 tons of waste to landfill per day. In addition, K-Lime strengthens Plymouth’s rural community by helping local farmers reduce their operating costs.