Asphaltene precipitation with partially oxidized asphaltene from water/heavy crude oil emulsion

• Asphaltene was converted into an effective additive and characterized various analysis.
• Asphaltene was precipitated in water/crude oil emulsion with oxidized asphaltene.
• About a half of asphaltene and a quarter of resin were separated.

A novel asphaltene precipitation method of using partially oxidized asphaltene was proposed to reduce the amounts of asphaltene in heavy crude oil. Partially oxidized asphaltene enhanced the aggregation of asphaltene in oil, and the precipitation of asphaltene from heavy crude oil. By adding a small amount of partially oxidized asphaltene in water/diluted-crude-oil emulsion, a half of asphaltene and a quarter of resin in the feed stream were separated by a single cycle of centrifugation. The degree of oxidation of partially oxidized asphaltene may determine the selective dissolution between the oil phase and the water phase. The partially oxidized asphaltene, which has amphiphilic functional groups, is adsorbed on the interface between asphaltene and water, and can therefore facilitate the aggregation of asphaltene dissolved in the oil. The interfacial adsorption may be controlled by the hydrophilicity and aromaticity of surfactants and may contribute to the aggregation and separation of asphaltene. Therefore, it is believed that the pretreatment of partially oxidized asphaltene could significantly reduce the asphaltene load in a solvent deasphalting process.