Continental Airlines on Monday made the first biofuel-powered commercial flight in the U.S. when its Boeing 737-800 made the trip from Houston to Chicago.
Alaska Airlines also will start biofuel-powered flights this week.
The Continental flight used fuel that was co-developed by Solazyme and Honeywell, which refined oil derived from algae into jet fuel that can be used for both commercial and military use.
Last year, United flew the first commercial flight powered by synthetic fuel made from natural gas.
Parent United Continental Holdings this week also reached an agreement to buy 20 million gallons of algae-derived jet fuel from Solazyme starting as soon as 2014.
Last year, United conducted the first flight by a U.S. commercial airline using synthetic fuel made from natural gas.
Meanwhile, Alaska on Wednesday will start flying biofuel-powered aircraft between Seattle and Washington and between Seattle and Portland, Ore.
Alaska’s Horizon Air unit will also start flights using a biofuel blend.