EFFECTS OF SOME OXYGENATED SUBSTITUTES ON GASOLINE PROPERTIES, SPARK-IGNITION ENGINE PERFORMANCE, AND EMISSIONS

Spark ignition engines are responsible to a considerable extent for th e major pollutants that are emitted in the atmosphere. The interest of researchers in the development of oxygenated fuel extenders has incre ased in recent years due to the removal of lead compounds from gasolin e in combination with the need to reduce the components with high ozon e-forming potential, i.e., aromatics and olefins. The purpose of the c urrent work was to investigate the ignition quality of compounds deriv able from renewable sources (furan derivatives and p-cresol), their ef fects on regulated emissions from conventional spark ignition engines, and their effects on gasoline properties. It was found that furan der ivatives and p-cresol are very effective antiknock compounds, thus all owing a reduced aromatic content in gasoline without any further negat ive effects on gasoline properties. Hydrocarbon and CO emissions were found to be a function of the air-fuel ratio (AFR) and independent of engine loading, whereas NOx emissions appeared to be affected not only by AFR and load but by the fuel's nitrogen content as well. Fuel NOx predominated over thermal NOx under low engine loading conditions. Mor eover, 2-methylfuran, furfurylamine, and p-cresol reduced HC and CO em issions relative to base fuel even at the same AFR level, whereas the effects of the compounds studied on NOx emissions were dependent on th e engine operating AFR level and on the nitrogen content of the fuel.