Ethylene–Vinyl Acetate Copolymer and Resin-Stabilized Asphaltenes Synergistically Improve the Flow Behavior of Model Waxy Oils. 2. Effect of Asphaltene Content

In part 1 (10.1021/acs.energyfuels.7b03657), the synergistic effect of ethylene–vinyl acetate copolymer (EVA) pour point depressant (PPD) and rensin-stabilized asphaltenes on improving the flowability of synthetic waxy oil has been verified. This paper is a continuous work studying the effect of the asphaltene content (0.01–3 wt %) on the synergistic effect between EVA PPD and resin-stabilized asphaltenes. The results showed that, in the absence of EVA and with the increase of the asphaltene content, the precipitated wax crystals of the waxy oil tend to grow gradually from initial big needle-like to smaller and more regular (spherical-like) particles with a larger amount; therefore, adding aphaltenes can only decrease the apparent viscosity of waxy oil at the temperature range slightly lower than the wax precipitation temperature (WPT) (the precipitated wax crystal amount is low), and the temperature range is broadened by increasing the asphaltene content. When the temperature is decreased far below the W...