Beijing:
China's first airplane to use biofuel made its inaugural flight on Friday morning, jetting off from Beijing International Airport.
According to Air China, the Boeing 747 used a biofuel developed from algae and
jatropha, a tree grown in south China that produces an oily nut.
Its launch comes as airlines struggle to find ways to keep costs down and reduce carbon emissions.
Among those who witnessed the two-hour-long maiden flight were airline officials, company executives and the media.
He Li, Vice President of Air China, said the flight was a "milestone" for the Chinese airline industry.
"It will help us greatly to reduce carbon emissions and give us more choices for aviation fuel," he said.
He also said the biofuel could be in use in commercial aviation in China within three or four years.
It was developed as part of a US-Chinese research venture launched last year to develop biofuels based on algae or oily nuts for use by Chinese airlines.
The venture was part of a series of research partnerships announced after Washington and Beijing pledged at a high-level meeting to co-operate closely in renewable energy, which both said was essential to fight climate change and could spur new industries.
China is on track to become the world's largest aviation market in the coming decades - and Beijing is aggressively promoting alternative fuels to clean up its environment and curb growing reliance on imported oil and gas.