Application of life cycle assessment to estimate environmental impacts of surface coal mining

Coal plays an important role in meeting the energy needs of the World. Given its abundance and low cost, its use is bound to increase with the growing energy demand. Despite its importance, there are concerns over coal\u27s environmental burdens. In order to extract and use coal in a sustainable manner, sustainability assessment has to be comprehensive. Life Cycle Assessment (LCA) provides systematic and quantifiable measures for assessing environmental burdens of products and processes. Extensive LCA work has been done on coal use, particularly in electricity generation, but, the coal mining stage has been neglected, for the most part. This has resulted in data gaps in the life cycle inventory (LCI) of coal and, consequently, in the LCIs for electricity and other products that are linked to coal. The situation has resulted in incomplete assessments of the sustainability of coal extraction and use, and potential for suboptimal strategies for reducing the potential impacts of coal, especially in the mining stage. The aim of this study was to employ the general principles of the ISO 14040-49 series LCA standards, adapting them where necessary, to estimate the cradle-to-gate life cycle impacts of coal from surface mining in the United States. Five strip mines that produce bituminous coal were used as case studies. The study assessed the life cycle water use, land use, energy use, abiotic resource depletion and climate change impacts for each mine and compared the performances of the mines based on the impacts. For the studied mines, the life cycle potential water use impact is 178 liters/tonne of processed coal at the mine gate. The potential land use impacts range from 3 to 10 m²- year/tonne. The potential energy use impacts vary from 97 to 181 MJ/tonne, the abiotic resource depletion impacts vary from 7.8 to 9.4 kg Sb-equivalent/tonne, and the climate change impacts range from 38 to 92 kg CO₂-equivalent/tonne. This study provides insight into contributions of mining processes to the impacts of coal. The results of the study contribute the much needed information to fill the data gaps in the LCI of coal, and provide baseline information that can aid the coal mining industry and public policy makers in the development of strategies and policies to sustainably exploit coal --Abstract, page iii