Abstract
Asphaltene aggregation and flocculation in upstream and downstream industries cause severe problems due to phase separation and asphaltene particle growth. This work aims to esterify tannic acid (TA) at different molar ratios of heptanoyl chloride (HC) 1:3, 1:6, and 1:9, producing species TA-HC3, TA-HC6, and TA-HC9, respectively. The synthesized esters were characterized by Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (H-1-NMR), and thermal analyses. Their performances as asphaltene dispersants of Arabian heavy crude oil were assessed by dynamic light scattering (DLS), ultraviolet-visible (UV-Vis) spectroscopy, and viscosity measurements. All specimens (TA-HC3, TA-HC6, and TA-HC9) dispersed asphaltene, and their dispersal abilities increased with increasing number of alkyl chains (i.e., TA-HC3 > TA-HC6 > TA-HC9).