Regeneration of Insulating Mineral Oil by Carbonated Amorphous Calcium Phosphate–Chitosan Adsorbent

In this study carbonated amorphous calcium phosphate (CACP) microparticles were prepared for use as an alternative adsorbent to replace bauxite in the removal of polar compounds present in mineral oil previously used in transformers. Chitosan was used to bind the adsorbent CACP microparticles together. This material showed a better performance than bauxite in relation to the colour and interfacial tension (IT) of regenerated oil. Also, this adsorbent may offer an interesting alternative environmentally since, after extraction of the residual oil with an organic solvent it could be disposed of in soil providing macronutrients such as calcium, carbon, nitrogen and phosphorous.