Partially Oxidized Asphaltene as a Bitumen Viscosity Reducer

Abstract

Heavy oil/bitumen with asphaltene requires high energy consumption for transportation, because of its high viscosity. This often causes serious pipeline problems; therefore, it is necessary to reduce the viscosity to resolve these issues. In this paper, we propose a new simple method to reduce the viscosity of diluted bitumen using partially oxidized asphaltene without removing asphaltene. This partially oxidized asphaltene, modified by exposing asphaltene to ozone, has a strong affinity to nonoxidized asphaltene via π−π stacking, hydrogen bonding, and acid−base interaction. The added oxidized asphaltene thus facilitated the agglomeration of asphaltene, so that the hydrophilic part can be hidden, and a small amount (1250 ppm) decreased the viscosity of diluted bitumen by up to 45%. We investigated the change in rheological properties of the diluted bitumen for various oxidized fractions of asphaltene and for various fractions of oxidized asphaltene to asphaltene. We showed that the decreased shear viscosity is likely to originate with the increased particle size of the asphaltene, that is, not the change in interactions between the asphaltene particles, but rather from their nonuniform distribution in size.

Asphaltene oxide promotes a broad range of synthetic transformations

“…Previous reports of oxidizing asphaltene to facilitate its separation from crude oil 14 or to reduce bitumen viscosity 16 have shown that treatment with potassium permanganate 14 or ozone 16 resulted in increased hydrophilicity, which ultimately facilitated precipitation from oil. We hypothesized that such oxidized derivatives of asphaltene, termed asphaltene oxide (AO), may function as economically viable catalysts due to the low cost of the precursor while providing insights into the intrinsic chemistry displayed by GO and other carbocatalysts 17 .…”

Synthesis, Characterization, and Mechanism of Copolymer Viscosity Reducer for Heavy Oil

“…In fact, both differences and relationships exist between the viscosity and the pour point in terms of certain physical properties that affect the viscosity of heavy oil. Thus, asphaltene should be considered the main factors affecting viscosity reduction, but the effects of resin and paraffin and the self-aggregation behavior of the highly viscous contents of crude oil should not be ignored …”

“…Thus, asphaltene should be considered the main factors affecting viscosity reduction, but the effects of resin and paraffin and the self-aggregation behavior of the highly viscous contents of crude oil should not be ignored. 17 Asphaltene consists of alkyl branches made up of C, H, and O and the functional groups of heterocyclic polycyclic and aromatic hydrocarbons or naphthene. The molecules of asphaltene interact with each other to form hydrogen bonds as an interlocking network of complex structures.…”

Study on the Effect of Different Viscosity Reducers on Viscosity Reduction and Emulsification with Daqing Crude Oil

“…However, due to the complex stratum, low stratum temperature, high content of crude oil gel, and asphaltene, the stranded crude oil has high viscosity, which brings great challenges to its exploitation and transportation [ 3 , 4 , 5 ]. Therefore, reducing the viscosity of heavy oil and improving its fluidity are urgent problems to be solved [ 6 , 7 , 8 , 9 , 10 ].…”