We recycle the used cooking oil from our kitchens into biodiesel, which we use to fuel more than half of our delivery trucks. We do it by collecting used cooking oil from our restaurants. At a processing facility in Liverpool, the oil is left to settle in large tanks. Smaller and lighter particles float to the top, while heavier ones sink to the bottom. The oil is gently heated and spun to remove water and solids. At this point a process called esterification takes place, a chemical reaction that produces biodiesel. Then filtration and distillation take place. At that point, the biodiesel is ready for use in our delivery trucks.
We make minor modifications to their engines so they can be fuelled by biodiesel as well as traditional mineral diesel. Almost all of our restaurants recycle their cooking oil in this way, and those that can't at the moment are working hard to make it possible.