Kinetika reakcije elementarnog sumpora i srebra u sintetskim estrima i poređenje sa mineralnim uljima
Sažetak
Decenijama unazad, smatralo se da je problem korozivnog sumpora isključivo vezan za mineralna ulja. No, najnoviji slučajevi iz industrije opovrgli su ovu pretpostavku. Prisustvo elementarnog sumpora u izolacionom ulju izaziva koroziju srebrnih kontakata i posledično rezultuje havarijom energetskih transformatora. Cilj rada je utvrđivanje kinetike reakcije elementarnog sumpora i srebra u sintetskom estru u temperaturnom opsegu 120-180°C. Rezultati pokazuju da kinetika reakcije srebra i elementarnog sumpora sledi zakon prvog reda. Uporedna analiza posmatrane reakcije u sintetskom estru i u mineralnom ulju, u definisanom opsegu temperatura, pokazuje da se reakcija brže odigrava u sintetskom estru, zbog čega je i primena odgovarajućih mera vremenski ograničena.
Reference
P. Rozga, A. Beroual, P. Przybylek, M. Jaroszewski, and K. Strzelecki, “A review on synthetic ester liquids for transformer applications,” Energies, vol. 13, no. 23, p. 6429, Dec. 4, 2020.
M. Dahlund et al., “Understanding the presence of corrosive sulfur in previously non-corrosive oils following regeneration,” in Proc. 77th Doble Client Conf., Boston, MA, USA, p. IM-5, 2010.
S. Samarasinghe, C. Ekanayake, H. Ma, T. Saha, J. Baniya, D. Allan, and G. Russell, “A risk assessment for utilities to prevent transformer OLTC failures caused by silver sulphide corrosion,” IEEE Trans. Power Deliv., vol. 37, pp. 2394–2402, 2022.
Testing of Insulating Oils—Detection of Corrosive Sulfur, Silver Strip Test, Standard 51353, 1985.
Standard Test Method for Corrosive Sulfur in Electrical Insulating Liquids, Standard D1275-15, ASTM, 2015.
J. M. Lukic, S. B. Milosavljevic, and A. M. Orlovic, “Degradation of theinsulating system of power transformers by copper sulfide deposition: Influence of oil oxidation and presence of metal passivator,” Ind. Eng. Chem. Res., vol. 49, no. 20, pp. 9600–9608, Oct. 2010.
J. Jankovic, J. Lukic, D. Kolarski, D. Veljović, Ž. Radovanović, and S. Dimitrijević, “Isotherm, thermodynamic and kinetic studies of elemental sulfur removal from mineral insulating oils using highly selective adsorbent,” Materials, vol. 16, no. 9, p. 3522, May 4, 2023.
M. Facciotti et al., “Passivators, corrosive sulphur and surface chemistry tools for the investigation of effective protection,” in Proc. Conf., MyTransfo Italy, pp. 27–35, 2014.
J. Lukic, J. Janković, D. Kolarski, D. Mihajović, S. Glišić, and A. Orlović, “Silver corrosion testing and mitigation,” Materials and Emerging Test Techniques, CIGRE Paris, p. 10893, 2024.
D. Kolarski, J. Lukić, J. Janković, and S. Glišić, “Kinetic Analysis of the Reaction of Silver with Elemental Sulfur in Mineral Insulating Oil,” Materials, vol. 18, no. 16, p. 3771, Aug. 2025
R. Foley, M. Bolton, and W. Morrill, “The reaction of silver alloys with sulfur in mineral oil,” J. Electrochem. Soc., vol. 100, no. 12, pp. 538–548, 1953.
R. Foley, W. Worrill, and S. Winslow, “The mechanism of the reaction between silver and sulfur in mineral oil,” J. Phys. Colloid Chem., vol. 54, no. 9, pp. 1281–1292, 1950.