Biodiesel from Oil recycling
There are close to 20 used cooking oil recyclers in Singapore however they all deal in large volumes (eg from F&B outlets). So unless you can sneak your used cooking oil into a bigger vat at a restaurant, it is unlikely you can get your oil recycled.
Why aren't these made available to the public? The quality and volume of used cooking oil coming from home kitchens does not make it feasible for businesses to collect it.