Effect of Anhydrous and Hydrous Ethanol on Performance and Non-Regulated Emissions of an HCCI Engine

The automotive sector is currently undergoing drastic changes, driven by the need to simultaneously meet increasingly stringent environmental regulations and achieve more efficient operation over a wide range of engine speeds and loads, while satisfying customer demands in terms of performance, safety, and reliability. In this study an HCCI engine is evaluated for performance and regulated and non-regulated emissions with anhydrous and hydrous ethanol. The Standard EPA Method 8315A was used to determine free carbonyl compounds by derivatization with 2,4-dinitrophenyhydrazine (DNPH). Carbonyls have been measured in emissions using DNPH impregnated cartridges and chemical analyses used high performance liquid chromatography (HPLC). Through the load range achievable, naturally aspirated lean anhydrous ethanol requires high intake temperatures. Although NOx emissions are lower with the use of hydrous ethanol, these emissions are much lower with the use of dry ethanol. The penalty of the use hydrous ethanol is an increase of unburned hydrocarbons and carbon monoxide. Total aldehyde emissions are seen to diminish when an HCCI combustion is carried out with hydrous ethanol. Our analysis gives evidence that HCCI engines can run efficiently on hydrous ethanol fuel and that utilizing hydrous ethanol fuel in HCCI engines improves the energy balance of ethanol production.