Major ap-42 revisions to the natural gas-fired boiler section and to all utility boiler factors

摘要

The EPA publishes emission factors in its Compilation of Air Pollutant Emission Factors (AP-42), and is charged with revising this document as new emission factors become available. Based on a wealth of continuous NO_x emission monitoring (CEM) data evolving from the acid rain program on utility boilers and a sizeable quantity of emissions data available for gas-fired boilers, the EPA conducted an update of AP-42 for NO_x emission factors for all fossil-fuel fired utility boilers and an update of all emissions factors for all gas-fired boilers. This update comprises information from over 900 boilers. As a result of the AP-42 update, the emission factors for utility boilers were expanded from 13 to 34 factors, speciated metals and organics for natural gas boilers were expanded from 17 to 44 compounds, and the accuracy of fine PM and VOC from natural gas-fired boilers was significantly increased. The new NO_x emission factors lowered the NO_x emisison rates by 30 to 40percent for most uncontrolled boiler categories, although they will raise the controlled NO_x emissions from selected low-NO_x burners equipped sources by a similar amount.