Thesis (M.Sc.)--Chulalongkorn University, 1997

The effect of oxygenated compounds on the emission of polycyclic aromatic hydrocarbons (PAHs) by an ISUZU model 4FG1 diesel engine has been investigated. Exhaust samples were sampled at no load and at engine speeds of 800, 1600 and 2400 rpm setting for each concentration of isoamyl alcohol. Base diesel fuel was blended with isoamyl alcohol at 4, 6, 8 and 10% by volume. The PAHs in the exhaust were analyzed by GC-MS. PAHs found in diesel exhaust were : naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthen and pyrene. It was found that the concentration of PAHs in diesel exhaust at engine speed 1600 rpm was slightly lower than at engine speed 800 and 2400 rpm. The concentrations of PAHs in diesel exhaust decreased with the increase of the concentration of isoamyl alcohol from 4 to 10% by volume.