Precise measurement of asphaltene stability in crude oil mixtures

The recently published ASTM D7157-23 “Determination of Intrinsic Stability of Asphaltene-Containing Residues, Heavy Fuel Oils, and Crude Oils” now includes Procedure B based on the SV10, the first fully automated S-value instrument developed by AD Systems (under license TOTAL Energies RC). The ILS conducted in 2022 has demonstrated its excellent repeatability and reproducibility, as it performed twice as well as the predecessor instrument while maintaining a good correlation with historical numbers.

The intrinsic stability (S-value) is an indication of the available solvency power of petroleum products, and its ability to retain asphaltenes in a colloidal dispersion. The higher the S-value, the less risk of asphaltene precipitation from the oil.

With the SV10, the laborious test procedure is totally automated, including toluene dilution, heptane titration, measurement of the flocculation point, results calculation, and post-test cleaning. The instrument can simultaneously run 3 samples to deliver fast results. This user-friendly instrument requires no special expertise or operator intervention during testing and eliminates the safety risks associated with handling hazardous solvents. With its unique temperature-controlled optical cell, the SV10 covers a wide range of samples, even those with low asphaltene content of <0.4%.

Beyond the ASTM D7157 standard report (S-value, So, Sa), the SV10 calculates additional values such as IN (Insolubility Number) and SBN (Solubility Blending Number), as well as the estimation of stability reserve and blending potential. These values for crude oils or fuels provide essential information for the assessment of their compatibility and blend stability while blended at different ratios.

The SV10 is the perfect analytical tool for refineries, blenders, and traders, allowing them to predict compatibility and increase the efficiency of refining and blending operations.