Effect of Dispersants and Flocculants on the Colloidal Stability of Asphaltenes

Role of ion-pair interactions on asphaltene stabilization by alkylbenzenesulfonic acids

“…Although both DBSA and OP [2] favored the formation of filamentary asphaltene flocculates, the mechanism by which these filaments formed was very different. In addition to the strong acid-base interaction between protonated asphaltenes (i.e., AH + ) and DBS À molecules, which was in accord with previous studies [1,3,[4][5][6][7][8], an additional electrostatic attraction was found between AH + -DBS À ion pairs. The latter was responsible for (i) the formation of very large and compact asphaltene flocculates, and (ii) the binding of these flocculates in series (generating long filaments) or in parallel (generating lateral ramifications).…”

“…As a result, DBSA is able to reduce the size of asphaltene aggregates to sub-micron scale [8,13], or even nanoscale [14], enhance the precipitation onset [6], and decrease the amounts precipitated [5,15]. However, it is unclear how the interactions between DBSA and asphaltenes affect the structure of asphaltenes.…”

“…Asphaltene interactions with DBSA are significantly stronger than with alkylphenols since acid-base interactions are stronger than hydrogen bonding [1,3,[4][5][6][7][8]. The acidic ASO 3 H groups of DBSA can protonate the basic groups of asphaltenes containing heteroatoms such as Nitrogen.…”

Influence of High Asphaltene Feedstocks on Processing

“…Thus, a decrease in n-heptane insoluble material is observed in the presence of dodecylbenzenesulfonic acid indicating an increase in the colloidal stability of the asphaltene constituents (Pillon, 2001). Poly(maleic anhydride-1-octadecene) polymer is an effective flocculant, and that the flocculation of n-heptane insoluble material varied depending on the weight ratios of the polymer to the asphaltene constituents.…”

“…Poly(maleic anhydride-1-octadecene) polymer is an effective flocculant, and that the flocculation of n-heptane insoluble material varied depending on the weight ratios of the polymer to the asphaltene constituents. The presence of an anhydride and unsaturation makes the maleic anhydride too reactive leading to chemical changes and the precipitation of asphaltene constituents and other aromatic molecules found in fuel oils (Pillon, 2001).…”