COST AND PERFORMANCE BASELINE FOR FOSSIL ENERGY POWER PLANTS LOW-RANK COAL TO ELECTRICITY WITH CCS

摘要

A substantial portion of the world's coal resources are comprised of lower-rank subbituminous and lignite coals. The U.S. Department of Energy/Energy Information Administration (DOE/EIA) estimates that low-rank coals account for nearly fifty percent of all global estimated recoverable coal resources. In the United States, subbituminous and lignite coals represent more than fifty percent of all estimated recoverable coals. Globally, low-rank coals are an important energy resource and the continued use of this plentiful fuel in à clean and efficient manner can supplement a diverse and secure domestic energy portfolio. For example, in OECD Europe, these coals represent approximately seventy percent of recoverable coals, and in some European countries, such as Germany, subbituminous and lignite coals dominate domestic reserves. Advanced clean-coal technologies such as integrated gasification combined cycle (IGCC) plants have shown significant promise in enabling continued use of coal resources in a clean, highly efficient manner. In addition, pulverized coal (PC) and circulating fluidized bed combustion (CFBC) plants designed with increasingly higher pressure steam cycles are showing similar progress. However, continued interest in reducing the carbon footprint of coal-based power plants is resulting in a growing impetus for the inclusion of carbon capture and sequestration (CCS) technologies. The inclusion of such technologies results in increased system complexity, lower overall plant efficiencies, and higher facility capital costs. The lower energy contents of subbituminous and lignite coals, compared to higher ranked bituminous coal, results in additional design and economic challenges for advanced clean coal plants, both with and without CCS. The low energy content, particularly for lignite, results in economic drivers to locate the plant near the fuel source. From the perspective of the United States, much of the low-rank coal resources are located in western, arid regions with limited water resources and high geographic elevations. The reduced air mass at elevation and limited water resources require further consideration in facility design and can result in higher capital costs and lower plant output. Ultimately, the combination of these technical and economic factors can influence technology selection (e.g., IGCC, PC or CFBC), and general conventions often considered for bituminous coal may not hold for low-rank coals. This study establishes performance and cost data for fossil energy power systems fueled by low-rank coals, specifically IGCC, PC, and CFBC plants at near-mine locations, all with and without CCS. The analyses are performed on a consistent technical and economic basis that accurately reflects current market conditions for plants starting operation in 2015.