How used cooking oil could hinder aviation's green fuel hopes

A joint investigation by The Straits Times and Climate Home News reveals how soaring demand for this key ingredient in sustainable aviation fuel has led to 'ridiculous' data and suspected fraud - undermining the industry's climate goals.

- David Fogarty

MELAKA, Malaysia - This is the starting point for the world's - and especially Europe's - lofty dreams of greener air travel: a collection point for plastic bottles filled with discarded frying oil in Malaysia.

One Saturday morning in May 2025 in the city of Melaka, volunteers in green T-shirts rushed over as Ms Adibah Rahim and her husband drove into the central square, eager to unpack, weigh and register her consignment of used cooking oil (UCO) - the "liquid gold" in European and Asian plans to ramp up production of sustainable aviation fuel (SAF).

Ms Rahim, a housewife, told The Straits Times it was her first time selling used oil, which she had collected over five to six months. She left the collection point RM90 (S$27) richer: At RM3 per litre of oil, it is a welcome boost to her family's household budget.

"We usually collect UCO from around 200 members of the public," said Mr Michael Andrew, sales manager for Evergreen Oil & Feed, the company running the Melaka collection with the local council. Evergreen, which runs similar collection drives elsewhere in Malaysia, supplies leading European SAF producers such as Spain's Repsol, UK-based Shell and Finland's Neste, the operator of SAF refineries in Europe and Singapore.

The aviation industry and many governments, including Singapore's, are pinning their hopes on SAF as a way to cut the sector's greenhouse gas emissions, which are set to increase as demand for flying grows.

And fuel suppliers around the world are scrambling for raw materials to meet new legal SAF blending quotas in Europe and growing demand elsewhere.

When it is made from waste such as UCO, rather than agricultural commodities such as soya or palm oil, SAF purportedly has up to 80 per cent less planet-heating emissions than kerosene jet fuel. And repurposing waste cooking oil avoids using land that would otherwise be used for food crops, or fuelling forest destruction.