Characterization of C80 Naphthenic Acid and Its Calcium Naphthenate

• Published in: Journal of dispersion science and technology 2008-03, Vol.29 (3), p.464-473
• Main Authors: Magnusson, Heléne, Hanneseth, Ann-Mari Dahl, Sjöblom, Johan
• Format: Article
• Language: English
• Subjects: Calcium naphthenic; Chemistry; Colloidal state and disperse state; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry; napthenic acid; oscillating drop; stable emulsions; tetraacid
• ISSN: 0193-2691; 1532-2351
• DOI: 10.1080/01932690701718966

A C80 naphthenic acid (tetraacid) and its calcium naphthenate have been characterized with respect to their interfacial properties at both the oil/water and the air/water interfaces as well as their thermal properties. Naphthenic acids in crude oils may give rise to different problems in oil production including naphthenate deposition and formation of stable emulsions. This may lead to severe disturbances of regularity and shut-in in the oil production. The interfacial activity and film properties of the compounds were examined by the oscillating drop method. The calcium naphthenate film was primarily elastic and solid-like. Measurements on the acid gave similar results, an elastic, solid-like film was formed, but the effect was less pronounced than for the calcium naphthenate. Langmuir-Blodgett films of the acid and its naphthenate were deposited on conducting substrates and subsequently analyzed by scanning electron microscopy, SEM. It was found that the pure acid formed crystalline structures in the interfacial film on compression. The calcium naphthenate, on the other hand, form a continuous amorphous film on the substrate.