ASTM D6296-98(2003)e1

The quantitative determination of olefins in spark-ignition engine fuels is required to comply with government regulations.

Knowledge of the total olefin content provides a means to monitor the efficiency of catalytic cracking processes.

This test method provides better precision for olefin content than Test Method D 1319. It also provides data in a much shorter time, approximately 20 min following calibration, and maximizes automation to reduce operator labor.

This test method is not applicable to M85 or E85 fuels, which contain 85 % methanol and ethanol, respectively.

1.1 This test method provides for the quantitative determination of total olefins in the C4 to C10 range in spark-ignition engine fuels or related hydrocarbon streams, such as naphthas and cracked naphthas. Olefin concentrations in the range from 0.2 to 5.0 liquid-volume % or mass %, or both, can be determined directly on the as-received sample whereas olefins in samples containing higher concentrations are determined after appropriate sample dilution prior to analysis.

1.2 This test method is applicable to samples containing alcohols and ethers; however, samples containing greater than 15 % alcohol must be diluted. Samples containing greater than 5.0 % ether must also be diluted to the 5.0 % or less level, prior to analysis. When ethyl-tert-butylether is present, only olefins in the C4 to C9 range can be determined.

1.3 This test method can not be used to determine individual olefin components.

1.4 This test method can not be used to determine olefins having higher carbon numbers than C10.

Note 1—Precision was determined only on samples containing MTBE and ethanol.

1.5 The values stated in SI units are to be regarded as the standard.

1.6 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.