Development of Eco-Friendly Transformer Oil from Neem Seed Oil using Periwinkle Waste Shell as Catalyst

Abstract

Abstract The urge for a sustainable and non-polluting industry has raised the need for a search for an alternative insulating fluid that could be used in transformers, because of the negative environmental effect of mineral-based insulating fluids. Natural esters from non-edible oil seeds showed to be feasible alternative, unfortunately they possess poor thermooxidative properties. Neem trees grow nearly on all types of soils and can be as old as 45 years before they start to produce less fruits. Neem tree can produce up to 50 kg of its fruits yearly from the tenth year and the seed oil content is 45 % making it a sustainable tree. The neem seed transformer oil (NSTO) was produced via catalysed transesterification process using neem seed oil and methanol with periwinkle shell as catalyst. Prior to the transesterification reaction the seed oil was degummed. The produced ester also underwent water treatment process. The produced NSTO density, water content, acidity flash point, pour point, viscosity, breakdown voltage, dielectric, relative dielectric constant, dissipation factor and resistivity properties were tested, presented and discussed. Results show that NSTO meet most of the standard requirements of new natural ester fluids as insulating oil. The dielectric breakdown voltage of the oil is 32 kV, which is more than the required for new natural ester fluids. The dissipation factor limit value for new natural ester of 0.20 % at 25 °C limit value was met by NSTO from 100 Hz to 400 Hz, and the relative dielectric constants of NSTO are 3.01 k, which value also meets the specification of between 2.9 k and 3.2 k. The pre-treatment of degumming of the seed oil prior to transesterification and water treatment of the produced ester appears to be a promising route for the production of electrical insulating oil for transformer.