You are here:
EXPERIMENTAL STUDY ON THE EFFECT OF SO2 ON PCDD/F EMISSIONS: DETERMINATION OF THE IMPORTANCE OF GAS-PHASE VERSUS SOLID-PHASE REACTIONS IN PCDD/F FORMATION
Citation:
RYAN, S. P., X. LI, B. K. GULLETT, C. LEE, M. CLAYTON, AND A. TOUATI. EXPERIMENTAL STUDY ON THE EFFECT OF SO2 ON PCDD/F EMISSIONS: DETERMINATION OF THE IMPORTANCE OF GAS-PHASE VERSUS SOLID-PHASE REACTIONS IN PCDD/F FORMATION. ENVIRONMENTAL SCIENCE AND TECHNOLOGY. American Chemical Society, Washington, DC, 40(22):7040-7047, (2006).
Description:
Co-firing coal in municipal solid waste incinerators (MSWIs) has previously been reported to reduce PCDD/F emissions due to increasing the flue gas SO2 concentration due to the fossil fuel addition. The present study was focused on understanding the mechanism predominately responsible for the suppressant effect of SO2 on PCDD/F formation and toxic equivalent emissions. PCDD/F formation from the injection of MSWI fly ash into an entrained flow reactor, designed to simulate the combustion and post-combustion conditions, gas-phase chlorine and sulfur addition (concentration and injection point flue gas temperature), fly ash injection, and time. The addition of Cl2 and non-sooting ethylene flame products to the reactor atmosphere (with fly ash injection) both resulted in substantial increases in total mono- to octa-chlorinated PCDF formation while only the addition of Cl2 resulted in an increase in PCDD emissions. These findings suggest that co-firing coal with MSW could reduce PCDD/F emissions that have been observed to increase in full-scale incinerators during start-ups or shutdowns.