Evaluation of polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emission in municipal solid waste incinerators

Abstract

This paper summarizes an engineering approach taken for 10 commercial MSW incinerators to formulate a basis for PCDD/F emission reduction schemes and to interpret the measurement results before and after the plant modifications of moderate scale. Control strategy of PCDD/F emission from the operating incinerators can be established on the basis of the interpretation of reliable measurements as well as understanding of the formation/destruction processes. The fate of PCDD/F is known to be influenced by the flue gas subprocesses: the initial formation/oxidation in the combustion chamber, reformation through synthesis, removal by adsorption, and catalytic destruction. A simplified model is proposed for PCDD/F level at various stages of the flue gas, basically integrating the reaction kinetic rates at the corresponding state. Since the kinetic rate is dependent on temperature, time-temperature history of the flue gas is considered as the important input data. Using the plant design and operating conditions, this global prediction model calculates the PCDD/F level not only at the stack but also at the process midstream. The model predictions are discussed along with measurement results from the different design of incinerator plants.