Heavy Metals Emissions from a Coal-fired Utility Boiler with AQCS System

摘要

The current understanding of HAPs metal emissions is based on field measurements from utility boiler-Air Quality Control System, AQCS, but with limited information on the effectiveness of individual equipment components. Mercury emissions were measured at a coal-fired utility boiler equipped with an SCR for NOx emission control, an SDA/FF for both acid gas and particulate emission control, and a subsequent WFGD system for SOx emission control. Measurements of HAPS present in the fly ash and gypsum product stream samples were also taken. The majority of the HAPS metals emissions exited the system through the fly ash product stream while a smaller proportion exited with the WFGD gypsum product stream. Only a minor portion of the HAPS metals were found in the WFGD purge water stream.