Investigation on the Acid Removal Performance of Oil Regeneration Sorbent Materials

  • S. Y. Matharage
  • S. Liu
  • Q. LiuEmail author
  • Z. D. Wang
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 598)


Transformers being one of the most expensive equipment in the networks require proper utilisation, which includes regular maintenance and application of life-extension techniques in feasible situations. Ageing process of the mineral oil and cellulose paper insulation system creates by-products such as moisture, acids and sludge, which further accelerate the degradation of the transformer insulation. Therefore, the removal of these by-products through oil regeneration could potentially prolong the lifetime of transformers. Typically, oil regeneration process includes percolation of oil through an adsorbent system followed by a filtration and a degasification process. Various sorbent types such as fuller’s earth, alumina, molecular sieves, silica-kaolin-sand mixture are used for the regeneration process. This paper investigates the acid removal performance of a modified alumina based sorbent, against two conventional sorbents i.e. fuller’s earth and alumina. It was found that the overall performance of modified alumina was higher than the conventional sorbent materials. Furthermore, all the three sorbent materials showed higher absorption capacity for low molecular weight acids than the high molecular weight acids.


Transformer Oil regeneration Fuller’s earth Alumina 


  1. 1.
    Venkatasubramanian, R., Liu, Q., Wang, Z.D., Marshal, P.: Assessment of regenerated oil through accelerated thermal ageing experiments. In: 2015 50th International Universities Power Engineering Conference (UPEC), pp. 1–4 (2015)Google Scholar
  2. 2.
    Friese, R.: Process of regenerating oil used for electrical purposes. US Patent 1,103,499 (1914)Google Scholar
  3. 3.
    Cox, D.C.: Process of reclaiming oil. US Patent 1,752,238 (1930)Google Scholar
  4. 4.
    Ambrose, H.A.: In chemical progress on insulating oil. Digest Lit. Dielectr. 3, 12–16 (1938)Google Scholar
  5. 5.
    Housley, J.E.: Reconditioning of insulating oils by activated alumina. Electr. Eng. 58(4), 172–178 (1939)CrossRefGoogle Scholar
  6. 6.
    Doble, F.C.: A new concept of insulating oil life characteristics. Trans. Am. Inst. Electr. Eng. Part III: Power Apparatus Syst. 71(1), 532–538 (1952)Google Scholar
  7. 7.
    Koestinger, P., Bruaroy, T. M.: Drying of power transformers in the field, applying the LFH-technology in combination with oil reclamation. In: CIGRE Paris Session, Paper No A2-106, Paris, France (2006)Google Scholar
  8. 8.
    Rasor, R.T., Moleski, H.L., Lubbeck, H.U.: Moisture in transformers and online dryer performance. IEEE PES T&D 2010, 1–5 (2010)Google Scholar
  9. 9.
    Sisic, E.: Transformer insulation regeneration and drying in online mode. Transformer Mag. 5(2), 116–122 (2018)Google Scholar
  10. 10.
    BS EN 62021-1: Insulating liquids - Determination of acidity - Part 1: Automatic potentiometric titration (2003)Google Scholar
  11. 11.
    Azis, N., Liu, Q., Wang, Z.D.: Ageing assessment of transformer paper insulation through post mortem analysis. IEEE Trans. Dielectr. Electr. Insul. 21(2), 845–853 (2014)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.The University of ManchesterManchesterUK

Personalised recommendations