Experimental Study of the Effect of De-asphaltene Method on Surface Morphology and Structure of Asphaltene

Problems associated with heavy organic deposition during the production, transportation, and processing of crude oils are one of the important issues in oil industry. Thus, accurate identification of asphaltene structure and surface morphology of asphaltene should be investigated. In this experimental study, thermal and thermal-evaporating de-asphaltene method for asphaltene separation at two different temperatures is used. The effect of temperature as precipitating agent and toluene as solvent agent on the structure and surface morphology of asphaltene is explored and compared by XRD and SEM technique. The results of SEM are shown the dependence of asphaltene morphology on the method of asphaltene separation. In all SEM images, pore, cavities and also agglomerated and smooth surfaces of asphaltene have been observed. Appearance of pores in the SEM images has been used as an indicator of the resin detachment. At thermal de-asphaltene method cylindrical asphaltene shapes change to smooth surface by altering the separation method to thermal - evaporation de-asphaltene. XRD results are shown that characteristic parameters, such as, layer distance between aromatic sheets have the same values for all de-asphaltene methods and are in agreement with other researches investigations, while the average height of stack aromatic sheets and the number of aromatic sheets in a stacked cluster by decreasing the temperature slightly increased. In thermal – evaporation method, this increasing of the number of aromatic sheets in a stacked cluster is observable. It›s indicated that asphaltene particles has more tendencies to aggregate and has smoother crystallite structure at mentioned conditions.