Keywords: environmental control, coal-based power systems, nitrogen oxide control, emissions
The U.S. Department of Energy's NOx control technology R&D programme for existing power plants
The U.S. Department of Energy (DOE) has established a set of national priorities through its Strategic Plan that includes the goal to promote secure, competitive, and environmentally responsible energy systems that serve the needs of the public. The Innovations for Existing Plants (formerly the Advanced Research and Environmental Technologies) programme, managed by the National Energy Technology Laboratory (NETL), develops advanced environmental control technologies for coal-based power systems. The programme also provides high-quality scientific information on present and emerging environmental issues for use in regulatory and policy decision-making. An important component of the programme is the research and development of advanced nitrogen oxide (NO2) control technologies. This effort is focused primarily on systems capable of controlling NO2 emissions to a level at or below 0.15 lb/million Btu at a cost significantly lower than state-of-the-art technology. The programme will also provide an improved understanding of the impact of these advanced technologies on related issues such as unburned carbon, waterwall wastage, and mercury speciation and capture. The research is driven by continuing pressure for further reductions in NO2 emissions from coal-fired utility boilers to address ground-level ozone and other environmental considerations including ambient fine particulates, visibility, eutrophication, and climate change. NETL is currently managing a portfolio of NO2 control technology R&D projects ranging from laboratory studies to modelling to full-scale demonstration. This paper will provide an update on the status of these projects covering ultra-low-NO2 burners, advanced reburning, selective non-catalytic reduction (SNCR), selective catalytic reduction (SCR), methane de-NO2, and enhanced-oxygen combustion.