Morphology and structure of asphaltene aggregates at different temperatures

فاقد چكيده فارسي

Asphaltene is the most polar compound in crude oil. Asphaltene deposition causes major problems in oil industry. Changes in the operating condition cause asphaltene to precipitate. In order to study the effect of temperature on morphology and size of precipitated asphaltene, a set of experiments were conducted. Experiments were done at atmospheric pressure and temperatures 25°C, 65°C and 95°C. N-heptane was used as the precipitant. Precipitated asphaltene was collected on filter paper 2 μm, washed with n-heptane and the structure of asphaltene was analyzed using Scanning Electron Microscopy. The deposited particles were amorphous aggregates with spherical and elliptical shapes. The results showed that at lower temperatures precipitated particles are more agglomerated and larger. Precipitated asphaltene decreases with temperature increase. By temperature increase large aphaltene aggregates break into small aggregates and become stable by bonding with resin molecules. The results were explained by the strength of bond between asphaltene aggregates and asphaltene-resin molecules.