Unusual patterns of interaction of asphaltenes with aprotonic solvents

Application of organic solvents for removal of asphalt-tar-paraffin deposits is one of the most widespread methods in technological processes of production, transportation, storage and processing of high-resin oils. In spite of certain results, the problem of directional solvent selection taking into account the nature of oil and asphalt-tar-paraffin deposits in specific conditions is far from being solved. The aim of the article is to test the hypothesis of the relationship between the solubility of asphaltenes and their average electron affinity and solvent ionization energy. Using the solubility isotherm of asphaltenes in non-ionogenic solvents, the solubility of West Siberian oil asphaltene samples and model fragments was evaluated. The studies have shown that asphaltenes with high effective electron affinity have the maximum solubility. Solvents with low ionization potential have the highest solubility, which confirms the thermodynamics of solubility through the formation of donor-acceptor complexes. The performed studies will help field specialists and engineers of service companies in scientifically justified selection of solvent depending on the type of deposits of heavy components of oil.