Yuji Muramoto, Yûichi Murakami
In recent years, the effective utilization of biomass resources has attracted considerable attention in the context of carbon neutrality and the development of a circular economy. Among various biomass wastes, used cooking oil (UCO), which is continuously generated from households and the food industry, is regarded as a promising renewable resource. This article outlines the current status of UCO generation and recycling and discusses the technical challenges associated with its application as an electrical insulating liquid. The authors' studies on the preparation of insulating liquids derived from UCO are also introduced. In particular, the effects of transesterification on viscosity and electrical insulation characteristics are presented. Finally, future challenges toward the practical utilization of UCO-derived insulating liquids are discussed.