Investigating Adsorbent-Based Partial Reclamation of Natural Ester Fluids for Transformer Applications

The present study examines the efficacy of an adsorbent-assisted reclamation process for restoring the properties of natural ester-insulating fluid. The selected adsorbent exhibits a high Brunauer-Emmett-Teller (BET) surface area and substantial pore volume, facilitating strong adsorption potential for degradation byproducts. Nuclear Magnetic Resonance (NMR) spectroscopy confirms a significant reduction in oxidation byproducts, including linolenic, linoleic, and saturated fatty acids, while oleic acid remains largely unaffected, indicating the selective removal of degradation compounds. Additionally, iodine index and saponification value analyses provide insights into the compositional changes in the reclaimed fluid. Fourier Transform Infrared (FTIR) spectroscopy further reveals the targeted adsorption of polar functional groups associated with thermal degradation. Physicochemical characterization demonstrates partial restoration of the reclaimed fluid's properties for potentially extending the service life of natural ester-based insulating fluids.