Oriented Screening of Deep Eutectic Solvents for Asphaltene Dispersion via Strong Hydrogen Bonding

Asphaltene deposition severely impacts oil operations (including production, transportation, and processing). Deep eutectic solvents (DESs) offer a green, tunable, and cost-effective solution, but traditional trial-and-error optimization is inefficient. To address this issue, we first constructed a validated asphaltene molecular model using characterization data and the Brown–Ladner algorithm, followed by targeted screening of optimal DESs through COSMO-RS-predicted thermodynamic parameters (ln γ and H^E). Three tailored DES formulations (DES1–3), combining tetraethylammonium chloride with short-chain alcohols (methanol/ethanol/isopropanol), exhibited exceptional asphaltene dissolution performance. Capillary deposition tests confirmed sustained micron-scale dispersion of asphaltene particles (>150 min), demonstrating remarkable stabilization effects. Spectroscopic (FT-IR, X-ray diffraction, and ¹H NMR) and computational (DFT) analyses identified specific O–H···O hydrogen bonding between DESs and asphaltenes, facilitating the partial exfoliation of polyaromatic aggregates. Complementary molecular dynamics simulations provided visual confirmation of the dissolution mechanism while quantitatively ranking hydrogen bond formation capacity (DES3 > DES1 > DES2), showing excellent correlation with experimental data.