Application of Highly Selective Adsorbent in the Removal of Elemental Sulfur and Other Corrosive Sulfur Compounds From Mineral Insulating Oils

Isotherm, Thermodynamic and Kinetic Studies of Elemental Sulfur Removal from Mineral Insulating Oils Using Highly Selective Adsorbent

“…The results are shown in Table 1. Based on the results of textural characteristics of HSA, such as specific surface area, S BET (29.28 m 2 /g), total pore volume, V total (0.2026 cm 3 /g), mesopore volume, V meso (0.2025 cm 3 /g), average pore diameter, D A (19.2 nm), and pore size distribution, D BHJ (25.1 nm), reported in previous work, HSA was classified as a mesoporous material [27].…”

“…HSA is a tailor-made adsorbent, called Tesla'Ssorb, based on silicon dioxide with bonded silver, specially designed to selectively remove reactive sulfur compound S 8 (in chemical reaction with deposited silver) in low amounts (up to 3 wt.% of adsorbent) and in short treatment time, in comparison to other adsorbents. The previous study indicated the efficiency of HSA to remove S 8, DBDS and oil ageing products, obtaining the oil with restored properties for further use in electrical equipment [27]. Moreover, it was shown that HSA was efficient in the removal of high concentrations of S 8 (approximately 45 mg/kg) to a final concentration below 1 mg/kg of S 8 , and therefore it can be successfully used to reduce the risks of power transformers failures and to extend transformer life [27].…”

“…The previous study indicated the efficiency of HSA to remove S 8, DBDS and oil ageing products, obtaining the oil with restored properties for further use in electrical equipment [27]. Moreover, it was shown that HSA was efficient in the removal of high concentrations of S 8 (approximately 45 mg/kg) to a final concentration below 1 mg/kg of S 8 , and therefore it can be successfully used to reduce the risks of power transformers failures and to extend transformer life [27].…”

“…For producing an adsorbent with high effectiveness for the removal of sulfur compounds corrosive to silver and to obtain restored oil properties with low acidity for further use in power transformers, both compounds, i.e., silver nitrate and ammonium hydroxide, are necessary [27].…”

“…Furthermore, the addition of ammonium hydroxide in a specific and optimal concentration range is necessary for the efficient neutralization of acidic by-products. On the other side, the said compound is not present in an excess amount, since it can reduce the mobility of silver ions for the reaction and the efficiency of corrosive sulfur removal, due to the possible formation of complex salts with silver, i.e., diamine silver (I) [(Ag(NH 3 ) 2 ] + complex [27].…”