An economic and emissions analysis of electricity generation using biomass feedstock in co-fired and direct fired facilities

Benjamin W Allen, Purdue University

Abstract

The Intergovernmental Panel on Climate Change (IPCC) has brought unprecedented attention to the role of greenhouse gases (GHGs) in the atmosphere. By law, the EPA is required to regulate six GHGs because they "threaten the public health and welfare of current and future generations" (EPA 2011). The EPA is now in the implementation stage of this law. A preliminary set of regulations is being developed for review by interested parties. In the United States, the electricity generation sector is a large emitter of carbon dioxide (CO2). Electricity generation accounts for 35% of the CO2 emissions. Biomass has gained attention in this industry because CO2 absorbed during growth offsets the CO2 emitted during combustion. Utilities and policy makers have a need for information regarding emissions from electricity generation using biomass. Also, technology and feedstock costs for electricity generation using biomass are not well established. This analysis combines elements from the existing literature to provide a more comprehensive analysis of electricity generation from biomass resources. A spreadsheet model is used to evaluate the long term cost and life cycle emissions of pollutants associated with using biomass for electricity generation. Three potential biomass feedstocks (willow, miscanthus, and corn stover) are analyzed. Co-firing and direct firing technology pathways for electricity generation are also compared. Co-firing is found to be less expensive than direct firing due to costs associated with biomass production and the relatively low cost of coal. Emissions of both technologies are primarily driven by the combustion of the feedstock. CO2 emissions are much lower for direct fire technologies since the combustion emissions are offset by CO2 absorbed during plant growth. SOx emissions are also lower for direct firing technologies. Particulate and NOx emissions are higher for direct firing than co-firing. These findings support the conclusion that biomass is a more costly feedstock than coal. Co-firing is a less expensive pathway for generating electricity with biomass but is associated with higher CO2 and SOx emissions. Further analysis is needed to analyze the increased costs associated with greater pollution control technologies.

Degree

M.S.

Advisors

Preckel, Purdue University.

Subject Area

Alternative Energy|Agricultural economics

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