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Abstract
Carbon dioxide emission into the atmosphere from electricity generation has become a concern from a climate change perspective. Replacing coal in Georgia's power plants with biomass can be an effective strategy to reduce carbon dioxide emissions. This dissertation aims to assess the sustainability of using biomass to replace coal in the power plant. Chapter 1 provides a general introduction and literature review of the subsequent chapters. Chapter 2 evaluates nine feedstocks grown in Georgia—loblolly pine, corn stover, cotton stalk, bermudagrass, energycane, giant reed, miscanthus, napiergrass, and switchgrass—for their economic competitiveness and carbon emission compared to coal for power generation. Cost-benefit analysis and the framework of life-cycle analysis (LCA) was used to conduct this study. Torrefied wood chips were found to be the most economical and least carbon-intensive compared to coal. It would require a carbon tax of about $8 for every metric ton of carbon dioxide emitted by coal-electricity to make pine chips price-competitive against coal. Chapter 3 contains a market-clearing supply-chain model to satisfy timber demand at the traditional pulp and sawmills and additional bioenergy demand at the coal power plants of Georgia for 50 years. This chapter includes five forest types in Georgia—planted softwood, natural softwood, upland hardwood, bottomland hardwood, and mixed. It determines the number of acres harvested (varied by location, forest type, and age of the stands), quantity of timber produced and transported to the demand nodes (mills and power plants), and impact on stand carbon and carbon avoided via coal replacement. Replacing 10% coal with both pulpwood and logging residues was found to be the most beneficial from a carbon perspective. Chapter 4 analyzes the land use change in the presence of additional bioenergy demand in the coal-firing power plants for 50 years. Along with the variables analyzed in Chapter 3, this chapter analyzes how much acres would be available under each forest type. This chapter also includes grassland available in Georgia and assumes that coal is replaced by both wood-chips and grass-pellets. Replacing 100% coal with all three types of feedstocks (pulpwood, logging residues, and grasses) provided the highest carbon benefit when benefit from avoided carbon emission via coal replacement was accounted for with changes in the stand carbon. The research will feed into the current policy deliberations for reducing carbon emissions and making Georgia a carbon-neutral state.