Commercial Viability of Near-Zero Emissions Oxy-Combustion Technology for Pulverized Coal Power Plants

摘要

Oxyfuel combustion is one of the leading options for capturing and sequestering CO_2 from coal-fired power plants. Praxair and Foster Wheeler are working on an oxy-coal power plant design that is based on Foster Wheeler's oxyfuel boiler technology and Praxair's Near Zero Emissions CO_2 processing unit (CPU) for purifying CO_2-rich flue gas. This oxyfuel boiler is designed to efficiently use either air or oxygen as the coal oxidant. Near Zero Emissions is an advanced CPU technology that significantly reduces air emissions compared to conventional CPUs, while achieving significantly higher CO_2 capture rates. Foster Wheeler performed detailed performance analysis for retrofitting oxy-fuel technology to an existing 460 MWe (gross) pulverized coal power plant burning either low sulfur PRB fuel or high sulfur bituminous fuel. Flue gas recycle rates were selected such that furnace gas temperatures and wall heat fluxes in oxy-firing mode are approximately the same as when air-firing. Emissions generated in the boiler were predicted by 3-D CFD simulations. Praxair developed additional simulations using DOE's design basis guidelines and 550 MW net power output and Foster Wheeler's oxyfuel power plant design. Technoeconomic evaluations were performed for (a) retrofitting oxyfuel technology to an existing power plant and (b) building a new oxyfuel power plant. For both scenarios, evaluations were done for (a) an air-fired plant without CCS, (b) an oxyfuel plant with a conventional CPU and (c) an oxyfuel plant with a Praxair Near Zero Emissions CPU.