Molecular Aspects of Asphaltene Solvation

• Grant number: 25/14969-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Leandro Martinez
• Grantee: Lucas Avila Pinheiro
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 13/08293-7 - CCES - Center for Computational Engineering and Sciences, AP.CEPID

Abstract

The stability of asphaltenes in solution is one of the main challenges faced by the petroleum industry, due to their tendency to aggregate and precipitate under adverse conditions of pressure, temperature, and composition. These molecules, which constitute the heaviest and most polar fraction of crude oil, exhibit complex aromatic structures capable of forming supramolecular aggregates through ¿-¿ interactions and hydrogen bonding. The differential solubility of asphaltenes in aromatic solvents (such as toluene) and their insolubility in aliphatic solvents (such as n-heptane) reflects the critical role of molecular interactions in the solvation process. This project aims to investigate, through molecular dynamics simulations, the molecular mechanisms governing the solvation of asphaltenes, with a focus on proposing new solvents and understanding the stabilizing role of natural resins. Advanced tools from the ComplexMixtures.jl package will be employed, such as minimum distance distribution functions (MDDF), local coordination analysis, and decomposition by functional groups, to quantitatively characterize solvent-solute interactions in different model systems. By comparing aromatic and aliphatic solvents, the project seeks to elucidate the structural factors that promote or hinder asphaltene self-association, based on energetic, structural, and statistical analyses. The role of resins as steric barriers and their ability to alter the flocculation onset point-defined as the condition in which asphaltenes begin to aggregate and form visible particles (flocs) that may precipitate from solution-will also be modeled. The expected results will contribute both to the advancement of fundamental knowledge in molecular physical chemistry and to practical applications in the formulation of stabilizing additives. (AU)