Значение и использование

The determination of oxygenates is important in the manufacture of ethene, propene, 1-3 butadiene, C4 hydrocarbons, and C5 hydrocarbons. Alcohols, ethers, aldehydes, and ketones are trace impurities in these hydrocarbons. Oxygenates decrease catalyst activity in downstream polymerization processes.

Область применения

1.1 This test method covers the gas chromatographic procedure for the quantitative determination of organic oxygenates in C2, C3, C4, and C5 matrices by multidimensional gas chromatography and flame ionization detection. This test method is applicable when the hydrocarbon matrices have a final boiling point not greater than 200°C. Oxygenate compounds include, but are not limited to, those listed in Table 1. The linear working range for oxygenates is 0.50 mg/kg to 100 mg/kg.

1.2 This test method is intended to determine the mass concentration of each oxygenate in the hydrocarbon matrix. Oxygenate compound identification is determined by reference standards and column elution retention order.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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.

TABLE 1 Oxygenates and Typical Retention Times

ComponentsRetention Time (min) Dimethyl ether6.18 Diethyl ether8.44 Acetaldehyde8.89 Ethyl tert-butyl ether10.66 Methyl tert-butyl ether (MTBE)10.92 Diisopropyl ether11.22 Propionaldehyde (Propanal)12.00 Tertiary amyl methyl ether (TAME)13.19 Propyl ether14.00 Isobutylaldehyde14.10 Butylaldehyde14.50 Methanol14.91 Acetone15.39 Isovaleraldehyde16.00 Valeraldehyde16.10 2-Butanone (MEK)17.14 Ethanol17.51 N-propyl alcohol and isopropanol19.20 (co-elution) Allyl Alcohol20.00 Isobutanol, Tert-butyl alcohol, Sec-Butanol20.24 (co-elution) N-butanol20.84