Use of surfactants to mitigate precipitation of nonstable asphaltensdes

Abstract

ABSTRACT In this work, we examine the effectiveness inhibition of three different surfactants (cationic, anionic, and non-ionic) with respect to aggregation of the most unstable fraction, asphaltenes, obtained from Algerian crude oil that flocculates and precipitates during oil transport and storage. Their efficacy is compared with native resins that are extracted from the same oil. We reveal from the results that the cationic surfactant didodecyl dimethyl ammonium bromide (DDAB) displayed the highest capacity to inhibit asphaltenes aggregation. This surfactant can shift considerably the aggregation onset of asphaltenes with respect to the non-ionic octylphenopoly(ethyleneglycolether) X (TX-100) and anionic dodecyl benzene sulfonic acid (DBSA) surfactants. This finding is explained by the presence of both double alkyl chain and basic head polar (positive charge) in surfactant structure on one hand and the structural properties of studied asphaltenes (rich oxygenated negative charge sites and low aromaticity) on the other hand. Finally, the comparison between the effectiveness of native resin and the studied surfactants indicate the following order: DDAB > resin> TX-100> DBSA.