Journal Article

Physicochemical and Dielectric Characterization of Cashew Kernel Oil as Dielectric Liquid

Abstract

Natural esters are eco-friendly alternatives to the widely used mineral oil as electrical insulation in oil-filled equipment. In this study, crude cashew kernel oil was extracted from cashew nuts using cold pressing and solvent extraction methods. After chemical purification, the oil was analyzed using Fourier Transform Infrared (FTIR) spectroscopy to identify functional groups. Physico-chemical properties such as iodine value (23.5 g I2/100 mg), pour point (-4.3°C), density (894.0 g/cm³ at 30°C), and viscosity (65.0 mPa.s at 30°C) were determined. Additionally, thermal and dielectric properties, including specific heat capacity (2.49 J/kgK), activation energy (0.16 eV), dielectric constant (2.9), dielectric loss (0.589), and breakdown voltage (32.4 kV), were assessed. Although the pour point was low relative to other natural esters, the pour point as well as its viscosity and loss were high compared to mineral oil. Nevertheless, the oil exhibits excellent breakdown voltage and dielectric constant, making it potentially suitable for liquid dielectric applications. To use it effectively in oil-filled equipment, reducing viscosity and loss is essential.

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