Fractionation and Characterization of Mexican Crude Oils

Crude oils are intricate mixtures of hydrocarbon compounds; different physicochemical characterizations must be performed to get to know their complexity. A series of four typical Mexican Crude Oils (MCOs) with densities ranging from 30 to 9 °API was characterized through different physical, spectroscopic, and thermal methods. The four types of MCOs were also fractionated into saturates, aromatics, resins, and asphaltenes (SARA) through high-performance liquid chromatography (HPLC). The fractions obtained were subsequently characterized through different physicochemical techniques such as Fourier transform infrared (FTIR) spectroscopy, vapor pressure osmometry (VPO), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). VPO led to determining the average molar mass of each MCO fraction to be compared to those of the different Mexican petroleums. It was clearly observed that the molar mass of the resin and asphaltene fractions increases when crude oil gets heavier than saturate and...