Chapter 9 - Post‐Combustion Emissions Control

Abstract

This chapter explores post-combustion emissions control strategies, which include technologies for controlling particulate matter and acid gas control, with an emphasis on sulfur dioxide and nitrogen oxides. Particulate matter emissions from coal-fired electric utility boilers in the United States have decreased significantly since implementation of the 1970 Clean Air Act Amendments. Several particulate control technologies are available for coal-fired power plants, including electrostatic precipitators (ESPs), fabric filters (baghouses), wet particulate scrubbers, mechanical collectors (cyclones), and hot-gas particulate filters. Of these, ESPs and fabric filters are currently the technologies of choice because they can meet current and pending legislation for particulate matter levels. While cleaning large volumes of flue gas, they achieve very high collection efficiencies and can remove fine particles. presents options for controlling mercury, the newest pollutant to be regulated. It also discusses carbon dioxide capture from flue gas streams, which is anticipated to be regulated in the future. The increased CO2 concentration in the atmosphere from fossil fuel combustion is causing concerns for global warming. The capture and sequestration of CO2 from stationary combustion sources is considered an important option for the control of CO2 emission because CO2 is likely to be regulated in the future as part of a carbon management program. The leading candidate technology for CO2 capture from coal-fired power plants is also briefly discussed in this chapter.