Thermo-Chemical and Dielectric Properties of Bio-based and Eco-friendly Natural Ester Fluids: Power Equipment Applications

Increasing environmental concerns and depleting petroleum reserves are driving explorations for renewable and biodegradable insulating fluids for transformer applications. Conventional mineral oils face disposal challenges, prompting search for alternatives. Vegetable oil-based transformer fluids meet many of these needs. To address the above issue, one of our recent studies explored a non-edible vegetable oil-based natural ester, an eco-friendly and fire-resistant insulating fluid for application in transformers. This study analyses chemical properties of natural esters using various techniques, viz., Fourier-transform infrared spectroscopy (FT-IR) and Gas chromatography coupled with mass spectrometry (GC-MS). The natural ester was also examined for thermal properties including thermal conductivity, thermal degradation, and dielectric characteristics. Results were compared with conventional mineral oil in accordance with national and international standards. Our findings show that thermal conductivity of the natural ester studied in this context decreases by 10% as the temperature increases from 25 to 100 °C. Electrical properties meet the requirements as per IEC 62770 and have been proven to be an excellent alternative to mineral oil. Natural esters provide numerous benefits owing to their cost-effectiveness and environmental sustainability, in addition to being biodegradable and renewable, and do not compete with food industry. Adopting such natural esters as alternative insulating fluids in electrical equipment would lead to a greener future in transformer applications.