Ivan’s Childhood (1962), directed by Andrey Tarkovskiy
How could you dispose of your cooking oil when you’re done cooking? The easiest thing to do might be to pour it down your drain — but if you save it up and send it to a processing plant, it can gain useful new life as biodiesel, a biodegradable energy source which can run in diesel engines instead of refined petroleum.
From the TED-Ed Lesson Biodiesel: The afterlife of oil - Natascia Radice
Animation by Lippy