ST Paper, one of several companies owned by the STGroup, faced a challenge similar to that of other paper manufacturing plants: inefficient boilers fired by fossil fuels, high transportation and landfill costs incurred during paper byproduct disposal, and a business plan that needed to address sustainability.
Together, Global Energy Solutions Inc. of Wheaton, Illinois, and Hurst Boiler & Welding Co. Inc. of Coolidge, Georgia, helped address all three of ST Paper’s stated concerns. Not only has ST Paper reached several important energy and efficiency goals, the company recently was awarded a grant from the state of Wisconsin’s Focus on Energy.
“ST Paper celebrated the completion of its renewable energy system with the presentation of a check for $237,500 from Focus on Energy,” wrote the Green Bay Press Gazette. “The grant will be used to defray the cost of the company’s new biomass energy system.”
The equipment used in the project included a Hurst 1,500 hp boiler; a substoichiometric combination wet softwood biomass plus sludge fuel gasifier, combustor and heat-recovery system fed via metering bins; a dry electrostatic precipitator; and a mixed biomass fuel-handling system using a six-tree walking floor.
The Fuel
A readily available fuel for ST Paper to consider was paper sludge — a clean, renewable manufacturing process byproduct. However, with a moisture content of nearly 70 percent, paper sludge alone was not a viable solution. In order to reduce the fuel’s overall moisture content to a more acceptable level, ST Paper opted to mix fuels, adding clean, residual, construction wood products, also readily available.
The Savings
Both fuels — paper sludge and construction wood products — were previously transported for disposal at Wisconsin landfill sites at significant monetary and environmental expense. In addition, fossil fuel for the less efficient boilers represented a variable cost that was, at times, prohibitive. With the new solid fuel system, fuel costs are predictable and have been offset by the elimination of landfill and transportation fees.
Global Energy Solutions Inc., a Hurst Boiler representative, has assisted many Wisconsin-based manufacturing concerns with solid-fuel procurement and boiler efficiency challenges. Hurst Boiler & Welding Co. Inc. has exclusive solid-fuel boiler agents and boasts industrial and institutional campus renewable success stories throughout the Midwest and beyond.
Hurst Boiler & Welding Co. Inc. has designed, engineered and serviced a complete line of solid fuel, solid waste, biomass, gas, coal and oil-fired steam and hot water boilers since 1967 for thousands of satisfied customers. Hurst also manufactures a complete line of boiler-room peripherals such as blowdown separator surge tanks and pressurized feedwater tanks. For more information: 877/994-8778 • www.hurstboiler.com • info@hurstboiler.com