Quantifying the Benefits of Using Flue Gas Desulfurization Gypsum in Sustainable Wallboard Production

Electric utilities produce more than 11.2 Mt of flue gas desulfurization (FGD) gypsum annually. Approximately 7.5 Mt is used in wallboard production. This article examines the environmental and cost benefits associated with replacement of natural gypsum in wallboard with FGD gypsum. A life-cycle analysis program was used to quantify the benefits of using FGD gypsum from electric power production in wallboard construction. Comparisons were made between energy consumption, water use, and greenhouse gas (GHG) emissions associated with obtaining and processing virgin gypsum material and those with FGD gypsum. The added impact of disposing of the unused FGD gypsum in landfills was also considered using life-cycle inventory for data generated from construction, operation, and maintenance costs for Subtitle D (nonhazardous municipal solid waste) landfills. Based on 2007 consumption data, the use of FGD gypsum in wallboard manufacture and concomitant avoided landfilling of unused FGD gypsum reduced energy consumption by 1200 TJ, water consumption by 18 GL, GHG emissions by 83 kt CO2e, and had a cost savings of $49 to $64 million dollars. The 2007 reduction in energy consumption from using FGD gypsum in wallboard is commensurate with the annual energy use of 11,800 homes, 58% of the annual domestic water use in Nevada, and the removal of 11,400 automobiles from the roadway.