Performance Characteristics of Philippine Hydrous Ethanol-Gasoline Blends: Preliminary Findings

To reduce dependence on imported fossil fuels and develop indigenous biofuels, the Philippines enacted the Biofuels Act of 2006 which currently mandates a 10% by volume blend of 99.6% anhydrous bio-ethanol for commercially sold Unleaded and Premium gasolines. To urge a regulation review of the anhydrous requirement and examine the suitability for automotive use of hydrous bioethanol (HBE) blends, preliminary engine dynamometer tests at 1400–4400 rpm were conducted to measure specific fuel consumption (SFC) and power. In this study, HBE (95 % ethanol and 5% water by volume) produced from sweet sorghum using a locally-developed process, was blended volumetrically with three base gasoline fuels — Neat, Unleaded, and Premium. The four HBE blends tested were 10% and 20% with Neat gasoline, 20% with Unleaded gasoline, and 20% with Premium gasoline. For blends with Neat gasoline, the SFC of the 10%HBE blend was comparable with to slightly higher than Neat gasoline. The SFC of the 20%HBE blend was comparable with Neat gasoline up to 2800 rpm and lower beyond this speed thus being better overall than the 10%HBE blend. Compared to their respective commercial base fuels, the HBE-Unleaded blend showed lower SFC while the HBE-Premium blend yielded slightly higher SFC over most of the engine speed range. Between commercial fuel blends, the HBE-Unleaded blend gave better SFC than the HBE-Premium blend. Power was practically similar for the fuels tested. No engine operational problems and fuel blend phase separation were encountered during the tests. This preliminary study indicated the suitability of and possible optimum hydrous bio-ethanol blends for automotive use under Philippine conditions.