SOAP Saturates, Olefins, Aromatics, Polars

During analysis of some specific samples, such as shale-oil-derived distillates and products from FCC-MAT, we encountered high contents of olefinic compounds. The SAP method cannot provide separation of olefins. 

They elute with n-pentane as part of the saturate fraction. We further developed the SPE method to facilitate olefins separation (SOAP). 

There are not many ways to verily the quality of olefin separation. To compare the SPE results for olefins with the results by other methods such as FIA (ASTM D1319), a number of diesel samples were analyzed by both methods. Since there is a correlation between llie Bromine number and the olefin content of the sample, the criteria for sample selection was a relatively high value of the Bromine Number. The selected samples were  

Results of SPE separation of diesel fuel standard D-916 are presented in Table 3. 

Usually, there is a large variation in results for olefins determined by the FIA method in different laboratories, as shown in Table 3. The olefins content varies from 1.1 to 6.2vol%, the aromatic content ranges from 34.4 to 44.4vol% and the saturate content from 54.3 to 63.5vol%. The SPE results, 60.8wt% for saturates, 4.3wt% for olefins and 34.9wt% for aromatics, fall well within the range of these round robin FIA test results. 

---