Twenty tonnes of oil refined from leftover cooking oil will be exported from China to the Netherlands to be processed into aviation fuel, a Chinese company said Wednesday.

The oil was produced by Qingdao Fresh Bio-energy Technology Development Co., Ltd, for an order placed by SkyNRG, a biofuel supplier from the Netherlands, according to Zheng Dehua, the company's deputy general manager.

The Qingdao-based company produced the oil by combining waste oil and fat, including "gutter oil," or discarded cooking oil, after pretreating and distilling the substances, Zheng said.

Zheng added that the mixed oil will still have to be processed after reaching the Netherlands in order to turn it into usable biodiesel for aircraft.

The company has a capacity to annually produce 50,000 tonnes of biodiesel from gutter oil, according to Zheng.