Power transformer oil desulfurization by Mg–Al LDH /pRGo nanocomposite

Power transformers nowadays suffer from the failures caused by the corrosive sulfur content of the mineral oil used as the insulating material. The precipitation of cupper sulfide on the insulation paper leads to the formation of hot spots and semi-conducting parts which in turn cause the failure of transformer. To help with this issue and obtain a better lifetime for the transformers it seems essential to develop a regular method of desulfurization to make sure the level of corrosive sulfur compounds not to arise above critical level. Among the corrosive sulfur compounds, dibenzyl disulfid (DBDS) has proven to be of great importance and attracted a significant amount of interest in the investigation for the cause of power transformer failure [1].In this study, we aim to use Mg–Al layered double hydroxide /partially reduced grapheme oxide nanocomposite as a representative of a class of nanocomposites used for desulfurization of water, diesel fuel, JP-8 and etc. for the desulfurization of power transformer oil, specifically the DBDS content removal. The Mg–Al layered double hydroxide with partially reduced grapheme oxide (pRGO) three-dimensional (3D) porous nanocomposite containing CO32 - were synthesized in two steps: (1) a modified Hummers’ method [2] were used to fabricate the graphene oxide (GO), (2) layered double hydroxide (LDH) nanosheets were homogeneously grown on the surface of the GO sheets by an in situ co-precipitation technique [3]. The acquired Mg–Al LDH /pRGo nanocomposite was characterized by SEM-EDX, FT-IR, XRD and TEM. The desulfurization process was carried out by a batch method using different concentrations of DBDS ranging from 10 to 100 ppm dissolved in transformer oil along with the adsorbent under vigorous stirring in 323.15 K for 5 days. The adsorption level was determined by Gas Chromatography and the adsorbent showed promising results for desulfurization of the transformer oil.