Analysis on effect of ultrasonic process on non-edible ester oils physiochemical properties

Liquid insulation serves as an insulating medium in numerous high-voltage devices and it effectively dissipates the heat generated during operation. Typically, petroleum-derived mineral oil is employed as a liquid dielectric in oil bushings and transformers. Recent studies concentrated on developing alternative liquid insulation using natural esters derived from seeds and plants. Primary challenges associated with natural esters are viscosity and pour point, and it affects the cooling behavior of the insulation liquid. Hence, there is need to improve the viscosity and pour point performance of natural esters. This research focuses on non-edible natural esters, namely Jatropha oil, Karanja oil, and Mahua oil samples. Oil samples are subjected to ultrasonic treatment with an ultrasonic power of 500 W and frequencies of 20 kHz, 25 kHz, and 30 kHz for different time durations (30 min, 60 min, 90 min, and 120 min). The influence of ultrasonic wave frequency and different time periods on viscosity and pour point are investigated. As a result of this technique, due to the better cavitation process, Karanja oils viscosity is reduced to 39.76%, 32.53% and 25.30% for the ultrasonic frequencies of 20 kHz, 25 kHz, and 30 kHz respectively. Similarly, Mahua and Jatropha oil's viscosities are also reduced due to the ultrasonic process.