SKOWHEGAN — Sappi North America received an environmental award earlier this month for a project completed at the Somerset Mill.
Sappi was named a recipient of the Leadership in Sustainability — Water Award from the American Forest & Paper Association as part of its “Better Practices, Better Planet” Sustainability Awards Program. The project, titled Caustic Reclaim and Reuse, was accomplished in Skowhegan at the Somerset Mill.
The project aimed to reduce the volume of chemicals the mill purchased to meet environmental goals in the process it uses to remove sulfur dioxide in its boiler and to offset the use of acid in its onsite liquid waste treatment plant.
The Somerset Mill operates a large steam plant and uses demineralized water as a main makeup water source for its recovery boiler and two multi-fuel power boilers.
“Sustainability remains Sappi’s priority and is critical to our strategy. At the Somerset Mill, we strive to challenge industry standards and ourselves to create innovative methods to better our environment,” said Sean Wallace, managing director, Sappi Somerset Mill. “Receiving this recognition from AF&PA is an honor, and we look forward to being a part of the industry’s step toward the association’s ‘Better Practices, Better Planet 2020‘ sustainability goals.”
The boiler system was installed in 1989 with the goal to minimize the release of sulfur dioxide emissions into the atmosphere. Sulfur dioxide is a toxic gas that is a by-product of burning fossil fuels containing sulfur compounds.
Sandy Taft, Sappi’s director of sustainability, said the mill’s project consists of a large spray tower with multiple levels of nozzles that spray high rates of water into the flue gas in its path between the boiler and its exhaust stack. Reagents are used to keep the pH of the water neutral, neither too acidic nor too alkaline, which allows the sulfur dioxide to be removed in the wet scrubbing process.
The Somerset Mill’s project is expected to reduce reagents used in the removal of sulfur dioxide, as well as to reduce acid usage in the treatment of liquid waste.
The reclaimed water in turn reduces the demand for fresh water that the flue-glass desulfurization, or FGD, scrubber needs to meet its evaporation requirements by 12,000 gallons per day. By implementing a similar process, other mills can reduce chemical demand, saving the mill money.
“The project represents significant chemical and water savings by putting an effluent stream to good use,” Taft said. “This is not only important economically, but it gives Sappi another avenue to promote its sustainability efforts.
“Demonstrating sustainability with recognized projects such as this helps in terms of attracting talented people to the mill and building/maintaining our customer base.”
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