Olefinic hydrocarbons that may be present in denatured ethanol have been demonstrated to contribute to photochemical reactions in the atmosphere, and this can result in the formation of smog in susceptible urban areas.

The California Air Resources Board (CARB) has specified a maximum allowable limit of total olefins in spark ignition engine fuel. Denatured ethanol will be added at the terminals as an oxygenate additive and can contain olefinic species contributing to the total olefins present in spark ignition engine fuel. An analytical method is therefore necessary to determine total olefins in denatured ethanol intended for spark ignition engine fuel use. The test method is intended to be used by both regulators and producers.

The present test method is automated, does not require any sample preparation, and has a relatively short analysis time of approximately 20 min.

1.1 This test method covers the determination of the total amount of olefins in denatured ethanol to be used as an oxygenate additive in blended spark ignition engine fuels. The method of determination is supercritical fluid chromatography (SFC). The application range is from 0.1 to 1.0 mass percent total olefins. Results are expressed in terms of mass percent olefins.

1.2 This test method can be used for the analysis of denatured ethanol that is intended to be used as an oxygenate additive in commercial spark ignition engine fuels.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.