Combustion Control of Organic Emissions from Municipal Waste Combustors

More than two decades ago, researchers identified benzo(a)pyrene and other organic species in the emissions from incineration of solid waste. Chlorinated dibenzo-p-dioxins and-furans (CDD/CDF) were first detected in municipal waste combustor (MWC) emissions in 1977. Since then, CDD/CDF and a substantial number of other potentially hazardous trace organic species have been observed in the emissions from many MWC facilities. From fundamental perspectives, organic emissions are products of incomplete combustion and can be controlled to low concentrations through the optimization of the combustion process and the application of appropriate flue gas cleaning devices. CDD/CDF are some of the most widely studied organic compounds of environmental concern. EPA has announced that it intends to propose new rules for control of MWC air emissions. Technical background studies for these rules considered the control of CDD/CDF as a surrogate for controlling emission of "MWC organics." These studies on the control of CDD/CDF from MWC facilities provide useful information on strategies for controlling total organic emissions from combustion sources. Good combustion practice (GCP) is defined as those combustion conditions which lead to low emissions of trace organic pollutants. This article (1) identifies specific combustion conditions which are postulated to lead to low emission of organics (components of GCP); (2) summarizes experimental correlations between GCP components and organic emissions; and (3) briefly discusses strategies for applying GCP to ensure continuous control of organic emissions. Background information on CDD/CDF formation theories is also presented and additional reasearch needed to establish the effectiveness of combustion strategies for control of MWC organic emissions is discussed.