Shanghai’s city buses will run on biodiesel processed from “swill oil”—used vegetable cooking oil captured from gutters and drains—from next year, the Shanghai food and drug safety authorities announced following a toxic oil recycling program it conducted with Tongji University.
Biodiesel only accounts for small proportion of the bus fuel and is a supplement for diesel. The city has two processors, which have limited abilities, in handling the recycled swill oil.
Three years ago swill oil made the headlines in newspapers across China and internationally after it was found that most restaurants were using the oil—for cooking.
In 2011, Shanghai reported progress in swill oil testing, as a local government research institute identified a chemical substance which can help experts tell accurately and quickly whether cooking oil was dredged from gutters.
It remains a challenge to turn swill oil into biodiesel in real practice.—Gu Zhenhua, deputy director with Shanghai Food Safety Commission