Investigating molecular interaction between wax and asphaltene: Accounting for wax appearance temperature and crystallization

Three modes will improve the interaction of the wax-asphaltene molecules that eventually increase wax appearance temperature (WAT) within crude oil. The first mode takes place when the wax is composed of long-chain alkanes, and its aromatic compounds are low, and adjacent hydrogens in its constituent aromatic rings are substituted with long-chain paraffin. The second condition is when the wax is formed from low carbon number alkanes. In this case, the lower the asphaltene aromaticity and the carbon number of side alkyl chain, the higher its interaction with wax would be. The third approach occurs if naphthenic or aromatic structures exist in wax, and asphaltene aromatic rings are arranged as peri-condenses. Higher interaction of wax and asphaltene reduces wax crystals’ size. The presence of polar compounds in the molecular structure of the wax and asphaltene does not affect WAT, but the size and morphology of crystals alter in microscopic images. •The effect of wax–asphaltene molecular interactions on wax appearance temperature (WAT).•Microcrystalline wax with high naphthenic and aromatic ring percentages.•The molecular interactions will depend on their molecular structure through London driving force.