The report gives results of a study during which nitrogen oxide (NOx) emission rates from 30 boilers at 11 TVA coal-fired plants were calculated and compared with the calculated rate for each boiler type using EPA emission factors (AP-42). Current AP-42 emission factors for NOx from utility coal-fired boilers do not account for variations in either emissions as a function of generating unit load, or designs of boilers of the same general type, particularly wall-fired boilers. TVA recently compiled short-term NOx emissions data from 30 units at 11 TVA coal-fired plants. Analysis of these data indicates that: (1) to varying degrees, NOx emissions increase with increasing load for all but single- and opposed-wall-fired boilers; (2) using the current AP-42 quality rating scheme for each of the six boiler types, factoring in the TVA and recent literature data results in improved quality ratings for all NOx emission factors; and (3) there was no evident relationship between NOx emissions and fuel nitrogen content or fuel ratio (fixed carbon to volatile matter).

"December 1992." "EPA-600/R-92-242." Includes bibliographical references (p. 49-50) Photocopy. Microfiche.