Energy & Fuels, Vol.33, No.2, 708-713, 2019
Improved Chromatographic Technique for Crude Oil Maltene Fractionation
One common method for describing crude oils according to their composition is by grouping their chemical compounds into four categories: saturates, aromatics, resins, and asphaltenes (SARA). SARA analysis is based on the different degrees of polarizability and polarity of each group (Fan, T.; Buckley, J. S. Rapid and Accurate SARA Analysis of Medium Gravity Crude Oils. Energy Fuels 2002, 16, 1571-1575, 10.1021/ef0201228). Most of the available chromatography techniques used for SARA analysis suffer from limitations, such as using large amounts of solvent or sample and yielding irreproducible results. The advantages of previously used methods are combined into a single system for maltene (containing saturates, aromatics, and resins) analysis to obtain less loss of volatile components and more reliable results as well as to use less crude oil sample and solvent. In our proposed method, the system is closed and the possibility of evaporation is much lower than in an open column. The testing time for maltene analysis reduced from 7 to 2 days, and the amount of solvent and sample decreased by 90% of that which is used in the ASTM D2007 method.