Synthesis and characterization of imidazolium asphaltenes poly (ionic liquid) and application in asphaltene aggregation inhibition of heavy crude oil

New ionic liquids were synthesized from asphaltene colloids that aggregate in the petroleum sludge precipitated in the storage tanks and transportation petroleum pipeline. The alkyl side chains on the asphaltenes were oxidized to polynuclear aromatic carboxylic acids that catalyzed the formation of imidazolium ionic liquid cations. Heptylamine, glyoxal, and p-hydroxybenzaldehyde were used to prepare 1,3-diheptyl and 1,3-diheptyl-2-hydroxyphenyl imidazolium cations conjugated with asphaltenes carboxylate anions as AsIL and AHIL ionic liquids, respectively. The chemical structure, surface charges, particle sizes, thermal stability and thermal characteristics were assessed. The impact of AsIL and AHIL on the dispersion, solubilization, and inhibition precipitation of asphaltenes in the binary solvents and heavy crude oil was studied. The results demontrate that the prepared ionic liquid containing aromatic (AHIL) acts as an asphaltene dispersing and solubilizing agent to inhibit the asphaltene precipitation more than that containing AsIL. (C) 2020 The Author(s). Published by Elsevier B.V.