At an upmarket restaurant in the hotpot-loving Chinese city of Chengdu, diners plunge sliced meat and vegetables into cauldrons of spicy, oily broth, largely unaware that their leftovers are set to take on a second life as jet fuel.
With around 150,000 tonnes of used hotpot oil thrown out by restaurants in the city each year, local business Sichuan Jinshang Environmental Protection has found a niche processing the greasy waste and exporting it to be turned into aviation fuel.