Viability of ash-recycling as a disposal option following conversion of a coal-fired power plant to biomass

Abstract

The economic feasibility of recycling wood ash in a land application program was analyzed as an alternative disposal option following the conversion of Plant Mitchell, a coal-fired power plant, to biomass combustion. A GIS spatial distribution analysis of crop and forest land was used in to identify suitable land for ash-recycling. Estimates based on crop distribution and ten independent cost factors were varied for cost sensitivity analyses. The most sensitive factors were application cost, calcium carbonate equivalence (CCE), and moisture content. The abundance of suitable acreage minimized transportation cost sensitivity. The cost of an ash-recycling program for Plant Mitchell compared favorably to the cost of landfill disposal. A demonstration of the safe and effective use of wood-ash as a low cost and equivalent lime substitute is needed as economic justification for the land owner. As a demonstration and field study, a land application experiment was conducted to investigate the beneficial use of wood ash when utilized as a soil amendment in the production of woody energy crops.