United Airlines officially entered the biofuel age on Monday, by launching its first U.S. commercial flight that's partly powered by algae-based jet fuel.

United Continental Holdings (UAL, Fortune 500) said its subsidiary Continental Airlines was operating the flight on a Boeing (BA, Fortune 500) 737-800 from Bush Intercontinental Airport in Houston to Chicago O'Hare International Airport.

United said this flight makes it "the first U.S. airline to fly passengers using a blend of sustainable, advanced biofuel and traditional petroleum-derived jet fuel."