A Sandwich Layer Method for Moisture Extraction in Transformer Insulating Oils Using Metal Organic Frameworks

Removal of excess moisture from transformer oil (TO) is vital for the trouble-free operation of the transformer. Conventional oil filtration by dehydrating with heat and vacuum is a time-consuming method and mostly requires the shutdown of the transformer. Developing an efficient online desiccant for TO has significant operational and economic advantages. Metal organic frameworks (MOFs) are very promising in capturing, storing, and separating gas and water. The use of these frameworks in TO as water capture and removal agents is unexplored. In this article, a zirconium-based MOF 801-P is synthesized and interpolated into TO in three different methods, namely, direct powder addition, filter paper pouch (FPP) suspension, and sandwich layer filtration (SLF). Variation in the water content (WC) of fresh mineral oil (FMO) and oxidatively aged mineral oil treated by these three methods is analyzed. In addition, variation in electric strength, dielectric dissipation factor (DDF), relative permittivity, and dissolved gases in fresh and aged oils due to each method is also studied. Furthermore, a potential moisture extraction method using MOF 801-P in transformer is presented.