According to Baidu Encyclopedia, Americans invented an oil-absorbing sponge. This kind of oil-absorbing sponge is called oil sponge, and its main component is polyurethane foam. Based on the principle of efficient oil-water separation of super-hydrophobic sponge coated with covalent organic skeleton, the oil in water can be quickly dried and recycled.
Oily sponge is a micron-sized material, which can convert waste edible oil into biodiesel.