Synthesis and Application of New Amphiphilic Asphaltene Ionic Liquid Polymers to Demulsify Arabic Heavy Petroleum Crude Oil Emulsions

Abstract

Asphaltenes are heavy petroleum crude oil components which limit the production of petroleum crude oil due to their aggregation and their stabilization for all petroleum crude oil water emulsions. The present study aimed to modify the chemical structures of isolated asphaltenes by converting them into amphiphilic polymers containing ionic liquid moieties (PILs) to demulsify the emulsion and replace the asphaltene layers surrounding the oil or water droplets in petroleum crude oil emulsions. The literature survey indicated that no modification occurred to produce the PILs from the asphaltenes. In this respect, the asphaltenes were modified via oxidation of the lower aliphatic chain through carboxylation followed by conversion to asphaltene acid chloride that reacted with ethoxylated N-alkyl pyridinium derivatives. Moreover, the carboxylation of asphaltenes was carried out through the Diels–Alder reaction with maleic anhydride that was linked with ethoxylated N-alkyl pyridinium derivatives to produce amphiphilic asphaltene PILs. The produced PILs from asphaltenes acid chloride and maleic anhydride were designated as AIL and AIL-2. The chemical structure and thermal stability of the polymeric asphaltene ionic liquids were evaluated. The modified structure of asphaltenes AIL and AIL-2 exhibited different thermal characteristics involving glass transition temperatures (Tg) at −68 °C and −45 °C, respectively. The new asphaltenes ionic liquids were adsorbed at the asphaltenes surfaces to demulsify the heavy petroleum crude emulsions. The demulsification data indicated that the mixing of AIL and AIL-2 100 at different ratios with ethoxylated N-alkyl pyridinium were demulsified with 100% of the water from different compositions of O:W emulsions 50:50, 90:10, and 10:90. The demulsification times for the 50:50, 90:10, and 10:90 O:W emulsions were 120, 120, and 60 min, respectively. The interaction of the PILs with asphaltene and mechanism of demulsification was also investigated.