How to power a plane with leftover Chinese hot pot

CHENGDU – There is a ritual involved in creating the perfect Sichuan hot pot, and it involves fat – lots of it.

Diners first immerse slivers of meat in a spicy soup rich in molten animal tallow, then dip each morsel in a plate of vegetable oil before finally devouring it. It is a rich delicacy, one that produces about 12,000 tonnes of waste oil each month in the Chinese city of Chengdu alone.

So in 2016, a start-up began exporting some of that leftover restaurant grease to Europe and Singapore, where it gets recycled into fuel pure enough to power aeroplanes.

Responsible for about 2 per cent of the world’s total emissions of planet-warming gases, the aviation industry is under pressure to find greener ways to power its jet engines.

Several major airlines, including British Airways, Cathay Pacific Airways and Delta Air Lines, have pledged to replace about 10 per cent of their jet fuel with a sustainable alternative by 2030, and more than 50 have begun to experiment with it, but cleaner substitutes are still being developed.

Waste oil from kitchens is emerging as a major source of sustainable jet fuel because it does not displace food production or encourage deforestation to make way for crops. And China, with its large population and love for super-greasy hot pots, is already the largest exporter.

Turning gutter oil to gold

“Our mission is to make gutter oil fly to the sky,” said Mr Zhong Guojun, vice-president of Sichuan Jinshang Environmental Technology, which is behind the project.

The Chengdu-based company collects used oil, mostly from hot pot restaurants in the Sichuan capital of 16 million, and removes impurities such as sodium and metal particles.

Its end product is a biofuel precursor usually called industrial mixed oil, which is then packed onto ships that sail east along the Yangtze River to the port of Shanghai, from where it is exported to Neste Oyj, the world’s largest producer of sustainable aviation fuel, and to global energy giants, including BP and Eni, to be further refined into biodiesel or jet fuel.

Originally set up during China’s food safety crisis to stop contaminated “gutter oil” from being filtered and sold back to food vendors, Jinshang began to export the leftover fat for industrial use in 2016, when demand for biofuels from international refiners first took off.

China consumes more edible oil than any other country – more than 41 million tonnes a year. So far, less than three million tonnes of it ends up in the supply chain for biodiesel, a major type of biofuel that has surged in price amid rising European demand, according to a report by the state-owned People’s Daily in 2022.

That leaves a lot of room for growth, especially as governments and industry regulators tighten rules to meet emissions targets that are key to averting catastrophic global warming.

Go green or go bust

The International Civil Aviation Organisation launched a carbon offsetting and reduction scheme in 2016 that encourages the use of sustainable fuels in addition to technical and operational improvements.

The European Union is also tightening its rules, introducing new requirements for its planes and airports to blend sustainable aviation fuel with their regular jet fuel, with the sustainable fuel making up 5 per cent by 2030, and the percentage gradually rising to 85 per cent in 2050.

Sustainable aviation fuel remains much more expensive than its conventional counterpart, but those targets are forcing airlines to respond, with some teaming up with start-ups that are developing cleaner technologies.

“When there is a demand, the supply will catch up, and the demand is already here,” said Dr Chong Cheng Tung, an associate professor at China-UK Low Carbon College, Shanghai Jiao Tong University.

“So either you switch your fuel to green fuel, like bio jet fuel, or you have to pay a (big) premium for travelling.” BLOOMBERG