Effects of Short-Chain n-Alcohols on the Properties of Asphaltenes at Toluene/Air and Toluene/Water Interfaces

Author(s)

Martins, Raphael G. ^[1] ; Martins, Lilian S. ^[1] ; Santos, Ronaldo G. ^[1]

Affiliation

^[1] Ctr Univ FEI, Dept Chem Engn, Ave Humberto de Alencar Castelo Branco 3972, BR-09850901 Sao Paulo - Brazil

• Document type: Journal article
• Source: COLLOIDS AND INTERFACES; v. 2, n. 2 JUN 2018.
• Web of Science Citations: 1

Abstract

Crude oil asphaltenes contain a wide series of chemical species, which includes the most polar compounds and interfacially active agents from the petroleum. Asphaltenes have been considered to be implicated in foam and emulsion formation during the petroleum recovery and production process. In this work, the interfacial activity of organic solutions containing asphaltene and n-alcohols was investigated. Asphaltene extraction from a 28 degrees API crude oil produced 2.5 wt % of n-pentane precipitated asphaltene (C5I). Dynamic surface and interfacial tensions of asphaltene solutions were assessed by the pendant drop method. Asphaltene films were evaluated at the air-water interface using a Langmuir trough. Results were expressed by means of the interfacial tension time-dependence. Interfacial tension measurements showed alcohols reduce the toluene/water interfacial tension of asphaltene solutions. The interfacial tension was reduced from 23 mN/m to 15.5 mN/m for a 2 g/L solution of asphaltene plus n-butanol. Higher asphaltene concentrations did not affect the toluene/air surface tension. The effects of n-alcohols on the asphaltene surface activity was dependent on the asphaltene aggregation state. n-Alcohols modify the asphaltene film elasticity and the film phase behavior. (AU)

• FAPESP's process: 13/25880-3 - Interfacial properties of crude oil asphaltenes mixed with ethoxylated surfactants and medium chain alcohols
• Grantee: Ronaldo Gonçalves dos Santos
• Support Opportunities: Regular Research Grants