[Separation of C5-C7 hydrocarbon components on Al2O3 capillary column and its application]

The separation and qualitative analysis of 54 common C5-C7 hydrocarbon components on three Al2O3 capillary columns, including S type, KCl type and M type, were investigated in detail. The results showed that the separation of the 54 C5-C7 hydrocarbon components were partly different on these three Al2O3 capillary columns, and the most of C5-C7 hydrocarbon components could be well separated, except that some of them couldn't achieve a baseline separation or co-eluted. Linear temperature programmed retention indices of the 54 C5-C7 hydrocarbon components, including 15 C5 hydrocarbons, 25 C6 hydrocarbons and 14 C7 hydrocarbons, were determined on these three Al2O3 capillary columns. The determination of linear temperature programmed retention indices for these C5-C7 hydrocarbon components on Al2O3 capillary columns provided a basis for the qualitative analysis of them. At the same time, a real pyrolysis gas sample from one of the petrochemical plants was qualitatively analyzed according to the linear temperature programmed retention indices, and the contents of C5-C7 hydrocarbon components were determined. The application field of Al2O3 capillary column was expanded and it is helpful for the analysis of light hydrocarbons in petrochemical enterprises.