Biodiesel is one of diesel fuel alternative made from renewable resources such as vegetable oils and animal fats. One of the natural ingredients that can be used as a material in the production of biodiesel is waste cooking oil (WCO). Biodiesel from WCO can be made through a transesterification reaction using a CaO catalyst. https://allfixelectricales.shop/product-category/spst-9volt-relay/