气相色谱法快速准确检测炼厂气组成的研究

Rapid and accurate determination of components in refinery gas by gas chromatography

关键词:  气相色谱法  炼厂气  组成  分析方法  检测

Key words:  gas chromatography  refinery gas  component  analytical method  measurement

摘要:

通过对气相色谱测试条件进行优化,可快速准确地检测炼厂气中28组分,在 6 min内可分别实现FID检测器对C₁～C₆⁺气态碳氢化合物的检测,双TCD检测器对常见永久性气体的检测。同时,对分析方法的精密度、线性、检出限和准确性进行了研究。分析方法研究表明,采用恒流进样控制阀的精密度要优于减压阀进样,28组分气体在一定含量范围内均呈现出良好的线性,烃类组分的检出限在5 μmol/mol左右,永久性气体的检出限在30 μmol/mol左右。此外,在恒流进样控制阀基础上采用在线漂移补偿法后,测试结果的相对标准偏差均在0.5%以内,各组分的分析值与标称值间的相对偏差小于1%。 

Abstract:

The 28 components in refinery gas can be detected quickly and accurately by optimizing the test conditions of chromatography. The gaseous hydrocarbons of C₁-C₆⁺ can be detected by a flame ionization detector (FID) and the common permanent gases can be detected by double thermal conductivity detectors (TCD) within 6 min. At the same time, the precision, linearity, detection limit and accuracy of the analysis method were studied. The precision results indicated that the injection mode by control valve with constant flow is better than the mode of pressure reducing valve. The 28 components of refinery gas in a certain concentration range showed a good linear relationship. The detection limits of the analytical method both hydrocarbons and permanent gases were about 5 mol/mol and 30 μmol/mol, respectively. In addition, using the on-line drift compensation method on the basis of control valve with constant current, the relative standard deviation of the measured results is less than 0.5%, and the relative difference is less than 1% between the analytical value and the nominal value of each component.