A Comparison Study on Emission Characteristics of Using Higher Alcohol Oxygenates with Gasoline in a Multipoint Fuel Injection Spark-Ignition Engine

摘要

Usage of oxygenates has become common practice for improving gasoline properties. In thisstudy, two oxygenates, one from the ether family (diisopropyl ether (DIPE)) and one from thealcohol family (n-butanol), were mixed with gasoline at 5, 15, and 25 % by volume to get D5,D15, D25, N5, N15, and N25 blends. Blends of DIPE (D5, D15, and D25) and n-butanol (N5, N15,and N25) were tested in a four-stroke four-cylinder multipoint fuel injection spark-ignition engineat 0.33 MPa (brake mean effective pressure) over a speed range of 1,400 to 2,800 r/minwith 200 r/min increments. The performance and emission behavior obtained from blends ofDIPE and n-butanol were compared with base gasoline. Lower hydrocarbon and carbon monoxideemissions are observed for oxygenate blends than for gasoline. However, blends of DIPEand butanol emitted higher nitrogen oxide (NO_x) than gasoline. The retarded spark timing from14° before top-dead-center (bTDC) to 12° bTDC reduced NO_x emissions from blends. The studyalso concludes that DIPE is a suitable and comparable oxygenate additive to n-butanol andoffers high knock resistance equal to n-butanol.