Review of advances in combustion technology and biomass cofiring

Advances in combustion technology will be adopted only when they reduce cost and can be implemented with acceptable technical risk. Apart from technical risk, future decisions on new power plants will be principally influenced by trends in fuel cost, the efficiency and capital cost of new generating technologies, and environmental and regulatory policies including possible carbon taxes. The choice of fuel and generating technology for new power plants is influenced by an increasingly complex combination of interrelated factors: (1) current and future governmental polices on restructuring and deregulation of utilities, and environmental regulations that in the future could include taxes on carbon emissions; (2) macroeconomic factors such as proximity to load centers, electrical transmission lines, plant capital investment, delivered fuel cost, and fuel price stability; and (3) the state of development of new generating and environmental control technologies and the associated benefits and risks involved in their deployment, which are strongly related to fuel properties. This paper describes three advanced high-efficiency power systems for which the EERC has performed supporting research and development: (1) a coal-fired supercritical steam boiler with advanced emission controls; (2) an indirectly fired combined cycle using compressed air as the working fluid in a gas turbine (GT), fired either on coal alone or on coal and natural gas; and (3) two versions of a hybrid gasifier-pressurized fluidized-bed combustor (PFBC) system.