Study of the Effect of Natural Naphthenic Acid Salts on the Electrical Conductivity of Diesel Fuel as a Functional Additive

This study investigates the effect of metal salts of natural naphthenic acids (Ni, Co, Zn, Mn, and Fe) on the electrical conductivity of diesel fuel as functional additives, benchmarked against neat additive-free diesel distillate as a control. Each salt was introduced at mass fractions of ۰.۰۵, ۰.۱۰, and ۰.۱۵%, and conductivity was measured after storage periods of ۱, ۱۰, ۲۰, ۳۰, and ۴۰ days. The untreated control showed values of ۸۵, ۸۳, ۸۲, ۸۲, and ۸۲ pS/m, respectively. The results demonstrated that additive performance depended strongly on the metal center, concentration, and storage time, which was attributed to differences in dispersion, association, and ion-interaction behavior of the metal-carboxylate compounds in the diesel medium. Among the five salts, only the Zn salt at ۰.۰۵% consistently reduced conductivity below the untreated control, giving values of ۲۹–۷۲ pS/m compared with ۸۲–۸۵ pS/m for the control. All other metal–concentration combinations increased conductivity. The Co salt produced values of ۹۵–۸۷۰ pS/m, while the Fe salt reached ۱,۲۶۰–۱,۴۵۰ pS/m at ۰.۰۵% and approximately ۱,۰۰۰–۲,۰۰۰ pS/m at higher concentrations. The Ni and Mn salts showed intermediate effects, reaching approximately ۱,۰۰۰–۱,۱۵۰ pS/m at ۰.۱۵%. Overall, the Zn salt of natural naphthenic acid at ۰.۰۵% was the only tested composition that effectively reduced diesel fuel conductivity relative to untreated diesel.

کلیدواژه ها:

natural naphthenic acid ، metal naphthenate ، Diesel fuel ، Electrical conductivity ، functional additive ، antistatic additive