The report gives results of a study of the formation and emission of soot and polycyclic aromatic hydrocarbons (PAH) from both laminar flames and a turbulent continuous-flow combustor. Decreasing the atomizing pressure decreased the amount of soot and PAH produced in the latter system. Benzene fuel gave more soot and PAH than did kerosene, and the PAH from benzene were more substituted. Nitrogen- and sulfur-doped fuels did not affect total soot production. The distribution of soot and PAH within the flame was consistent with the concept that certain PAH may serve as intermediates in soot formation. The PAH formed during combustion of coal, wood, and kerosene were separated and identified by capillary column gas chromatography and mass spectrometry. The PAH from coal combustion were found to be similar to airborne PAH from Indianapolis, a high coal consumption area; those from kerosene combustion were similar to airborne PAH from Boston, an area of low coal consumption and high consumption of petroleum derived fuels. Nitrogen containing fuels primarily produce polycyclic aromatic compounds in which the nitrogen is in a cyano substituent (approximately 70%). This contrasts with the observation that nitrogen heterocyclic compounds are the major nitrogen containing compounds in airborne particulate matter.

Aug. 1978. Includes bibliographical references.