Session: 14-02: Carbon Capture & Cleaner Fossil Fuel Technologies II

Paper Number: 169690

169690 - Carbon Footprint of Electricity Generation From Waste Coal 

Abstract: 

“Waste coal” includes mixtures of coal and soil remaining on site from coal mining activities as well as waste streams of coal-containing slurries from coal preparation plants. As a few US companies have recently been promoting their use of “waste coal” as a sustainable approach to electricity generation from coal, it has become imperative to assess the validity of this claim from a life cycle perspective. We performed a cradle-to-grave life cycle assessment (LCA) of several pathways of “waste coal” electricity generation using data from existing power plant operations and supply chains in Pennsylvania, US. Although the power plants use higher efficiency designs like circulating fluidized bed combustion and short transportation distances along their supply chains, the low quality of the “waste coal” leads to higher life cycle greenhouse gas (GHG) emissions than generating electricity from typical bituminous or sub-bituminous coal. Relatively low carbon contents and heat contents, as well as high moisture contents due to coal preparation steps, lead to below-average power plant efficiencies. The omission of ash management in previous LCAs involving “waste coal” is problematic for a feedstock with an ash content between 40% and 61%. We investigated the claims of net-zero GHG emissions when combined with carbon capture and storage and co-firing of forestry waste biomass, discovering inaccuracies in some assumptions made by previous LCAs. Additionally, we critically assessed the validity of avoided emissions from removing the risk of uncontrolled burning of “waste coal” when it is not collected and used. We report that the studied scenarios lead to higher life cycle GHG emissions for electricity from “waste coal” relative to conventional coal, and we discuss the factors involved in cases in which the carbon footprint is more than doubled.

Presenting Author: Marie-Odile Fortier University of Nevada, Las Vegas

Presenting Author Biography: Dr. Marie-Odile Fortier is an Assistant Professor in the Department of Civil and Environmental Engineering and Construction at the University of Nevada, Las Vegas. Previously, from 2018 to 2022, she was an Assistant Professor in the Department of Civil and Environmental Engineering at the University of California, Merced. From 2015 to 2018, she was an Assistant Professor at the State University of New York College of Environmental Science and Forestry contributing to the development of interdisciplinary undergraduate and graduate programs in Sustainable Energy. Dr. Fortier’s research focuses on the geographically specific life cycle climate change impacts of energy systems, including land use change and albedo change impacts. Her research group, the Geospatial Energy Resources and Life Cycle Assessment (GERLCA) lab, uses LCA, GIS, and mathematical modeling to investigate how the carbon footprints of different fossil, renewable, and biomass energy systems vary spatially in order to optimize the energy transition towards decarbonization. In 2021, she received an NSF CAREER award towards this research in developing new geospatial methodology for energy life cycle assessments.