Search Results

This paper presents fuel property data and associated analytical methodology used in blending test fuels for portions of Phase I and Phase II of the Auto/Oil Air Quality Improvement Research Program (AQIRP). Information presented in this paper supplements the first published report of AQIRP fuel blending results by Pahl and McNally (1).* Fuel blending data are presented covering two segments of Phase I of the Program. The first is a two fuel matrix where the sulfur level is varied at two levels (50 and 450 ppm) through the addition of ditertiarybutyl disulfide. The second is an eleven fuel matrix where the effects of both volatility adjustment and oxygenate addition are investigated. Oxygenates tested include MTBE (methyl tertiary-butyl ether), ethanol, and ETBE (ethyl tertiary-butyl ether). Fuel volatility adjustments are made by changing RVP (Reid Vapor Pressure). Included with the fuel physical property data are individual fuel speciation profiles for all Phase I fuels.

The U. S. Treasury Department recently ruled that the ethanol blenders tax credit applies to ethanol used to make ETBE for blending with gasoline. As a result, ETBE may soon become a popular gasoline blending component. Like MTBE, ETBE adds oxygen to the fuel while contributing to other performance properties of the gasoline. Phillips Petroleum Company has completed limited driveability and material compatibility studies on gasolines containing ETBE and has determined the effect on various performance parameters such as octane, volatility, and distillation of ETBE in gasoline. Levels of ETBE ranging from 0.0 to 23.5 volume percent (3.7 weight percent oxygen) in gasoline were included in the investigation. Use in gasoline is currently limited to only 12.7 volume percent (2.0 weight percent oxygen) by the gasoline substantially similar rule. No detrimental effects of the ETBE on metal or elastomeric parts common to gasoline delivery and fueling system were found.