Advanced clean coal technology in the USA

Abstract

Coal is the most plentiful fossil fuel in the USA but its continued competitiveness with other energy resources will depend on the development of innovative technologies that enable the design of near-zero emission coal-based power plants. The US Department of Energy’s clean coal research, development, and demonstration programs address near-, mid-, and long-term technologies for improving the environmental performance, efficiency, reliability, and cost competitiveness of coal-based electricity generation. Vision 21, the long-term initiative to eliminate environmental concerns associated with coal use, focuses on technologies, including gasification, gas purification and separation, combustion turbines, fuel cells, and advanced steam cycles, that are likely to play key roles in the design of near-zero emission plants. These key technologies have in common the characteristic that they require advanced materials capable of withstanding aggressive environmental conditions and performing specialized functions when required. Examples of these critical materials include refractory linings for coal gasifiers, gas filters and sorbent systems to remove contaminants, ceramic membranes for separating oxygen from air and hydrogen from carbon dioxide, blading and other components for high-temperature combustion turbines, fuel cell electrodes and electrolytes, and boiler tubing and turbine components for advanced steam cycles. This paper describes technology pathways being pursued to achieve Vision 21 objectives and gives examples of advanced concepts, focusing on operating conditions and materials.