Development of the integrated environmental control model: Cost models of selective catalytic reduction (SCR) NO{sub x} control systems. Quarterly progress report, October--December 1993

Abstract

Selective catalytic reduction (SCR) is a process for the post-combustion removal of NO{sub x} from the flue gas of fossil-fuel-fired power plants. SCR is capable of NO{sub x} reduction efficiencies of up to 80 or 90 percent. SCR technology has been applied for treatment of flue gases from a variety of emission sources, including natural gas- and oil-fired gas turbines, process steam boilers in refineries, and coal-fired power plants. SCR applications to coal-fired power plants have occurred in Japan and Germany. Full-scale SCR systems have not been applied to coal-fired power plants in the U.S., although there have been small-scale demonstration projects. Increasingly strict NO{sub x} control requirements are being imposed by various state and local regulatory agencies in the U.S. These requirements may lead to U.S. SCR applications, particularly for plants burning low sulfur coals (Robie et al.). Furthermore, implicit in Title IV of the 1990 Clean Air Act Amendment is a national NO{sub x} emission reduction of 2 million tons per year. Thus, there may be other incentives to adapt SCR technology more generally to U.S. coal-fired power plants with varying coal sulfur contents. However, concern remains over the applicability of SCR technology to U.S. plants burning high sulfur coals or coals with significantly different fly ash characteristics than those burned in Germany and Japan. There is also concern regarding the application of SCR to peaking units due to potential startup and shutdown problems (Lowe et al.). In this report, new capital cost models of two SCR systems are developed. These are {open_quotes}hot-side high-dust{close_quotes} and {open_quotes}tail-end low-dust{close_quotes} options. In a previous quarterly report, performance models for these two systems were developed.