Asphaltene Aggregation: Influence of Composition of Copolymers Based on Styrene-Stearyl Methacrylate and Styrene-Stearyl Cinnamate Containing Sulfate Groups

Abstract

The stabilization of asphaltenes by chemical additives, resulting mainly from the action of amphiphilic molecules with low molar mass, has been widely used in the petroleum industry. Polymer materials can also be used as asphaltene stabilizers, although they can act as stabilizers or flocculants in function of their molar mass and/or composition. Asphaltene flocculation is also important in deasphalting crude oil or recovering polyaromatic molecules to be used as filler in polymer composites. In order to better understand the factors that affect the action of polymers on asphaltene phase behavior, we investigated a new family of compounds based on styrene-octadecyl methacrylate and styrene-octadecyl cinnamate, with varied sulfonation degrees. The results show that besides molar mass, the content of long pendant hydrocarbon chains (C18), the sulfonic groups content in the molecule and the polymer concentration directly influence the type of effect (stabilization or flocculation) on asphaltenes. The sulfonation of copolymers increases their stabilizing action by promoting stronger interaction of the additive with the asphaltene molecules by sulfonic groups. However, an excess of sulfonic groups promotes a reversal of this behavior, from stabilizing to flocculating, because a large amount of sulfonic groups in the same molecule brings the asphaltene molecules together and induces their aggregation.

Polycardanol and Poly(cardanol‐co‐styrene): Synthesis, Characterization, and Performance as Asphaltene Flocculant

“…Different kinds of polymers have been studied regarding asphaltene deposition in crude oil production . Previous studies have evaluated the behavior of asphaltenes in the presence of polycardanol (PCN) and sulfonated polystyrene, with different degrees of sulfonation.…”

“…The few studies available in the literature involving copolymers in the petroleum industry involve asphaltene stabilizers or flocculants. One of these studies is about multifunctional products, that is, products applied to solve at least two problems simultaneously, in this specific case as asphaltene stabilizer and paraffin inhibitor . Another study by our research group is about polymers able to act as asphaltene flocculants in a particular type of nonconventional oil, that is, assisting in further destabilization of the model system to assist the removal of suspended fine solids.…”

“…Among the components that have generated problems during the extraction of bitumen from oil sand, suspended fine solids deserve special attention . These studies with copolymers are gaining increasing importance in the oil industry …”

“…[6][7][8] Different kinds of polymers have been studied regarding asphaltene deposition in crude oil production. [9][10][11][12] Previous studies have evaluated the behavior of asphaltenes in the presence of polycardanol (PCN) and sulfonated polystyrene, with different degrees of sulfonation. These polymers have an amphiphilic structure, with a polar group, able to interact with asphaltene molecules.…”

“…One of these studies is about multifunctional products, that is, products applied to solve at least two problems simultaneously, in this specific case as asphaltene stabilizer and paraffin inhibitor. [11][12] Another study by our research group [13] is about polymers able to act as asphaltene flocculants in a particular type of nonconventional oil, that is, assisting in further destabilization of the model system to assist the removal of suspended fine solids. Tar sand or oil sand is a type of nonconventional oil that contains bitumen impregnated with unconsolidated sand.…”