Advanced Analytical Techniques for Comprehensive Characterization of Vacuum Residue Oil (VRO): A State-of-the-Art Review

Abstract

The characterization of vacuum residue oil (VRO) presents substantial challenges due to its complex and diverse composition, including a wide range of heavy hydrocarbons and high molecular weight compounds. Existing literature has extensively documented various advanced analytical techniques for assessing VRO, yet the complexity of this material continues to pose difficulties in fully understanding its properties and optimizing its industrial applications. This review builds on prior research by providing a comprehensive overview of the latest characterization methods, categorizing them into three primary areas: physical and chemical bulk property analysis, saturates, aromatics, resins, and asphaltenes (SARA) fractionation, and molecular modeling approaches. The report highlights global standards and variations in VRO properties, with particular focus on the intricate correlations between physical properties such as refractive index and density, and the molecular weight of specific fractions. By compiling and synthesizing these advancements, this review not only underscores the significant diversity within VROs but also clarifies the crucial role of advanced techniques, such as FTIR, NMR spectroscopy, and chromatographic methods, in enhancing our understanding and optimizing the processing of VROs in industrial applications. The insights provided here aim to bridge the gap between existing characterization methods and their practical application in optimizing conversion processes in commercial residual oil units.