The cogen project had a huge problem: There was too much sulfur in the biogas. Corey Zarecki, director of engineering and operations for the Envision program at Gundersen Health System, had initiated the project and dove right in to fix it, according to an article from Building Operating Management on the FacilitiesNet website.
The cogeneration system was part of a partnership with a nearby brewery — the engine would produce electricity from the brewery’s waste process and the brewery would use the heat in its anaerobic digester. But the brewery’s waste process was producing biogas with an unacceptable level of sulfur, threatening to deep-six the economics of the project. “Internal combustion engines don’t like sulfur,” said Alan Eber, Gundersen’s director of facilities.
So Zarecki researched, experimented, designed, piloted and eventually patented a chemical process to reduce the amount of sulfur in the biogas. Clean energy project back on track.
Gundersen Health System is the first health system in the United States to be fully energy independent. The system’s headquarters campus in La Crosse, Wis., contributes to that goal with a geothermal system and a biomass boiler with a back pressure steam turbine.