The friendly skies of United Airlines are now friendlier for the environment as subsidiary Continental flew the first commercial flight on advanced biofuel yesterday.

“United is taking a significant step forward to advance the use of environmentally responsible and cost-efficient alternative fuels,” said Pete McDonald, United’s executive vice president and chief operations officer. “Sustainable biofuels, produced on a large scale at an economically viable price, can one day play a meaningful role in powering everyone’s trip on an airline.”

A Boeing 737-800 made the historic flight from Houston to Chicago Monday on an algae-derived renewable jet fuel made by Solazyme. The plane was fueled with 40 percent Solajet™ and 60 percent petroleum-derived jet fuel. United also signed a letter of intent with Solazyme to purchase up to 20 million gallons per year of renewable jet fuel starting in 2014.

“Looking at United, a company that understands the sustainability of tomorrow means environmental responsibility today, we see a true pioneer in the future of flight,” said Jonathan Wolfson, Solazyme’s CEO. “Solazyme is deeply committed to commercializing our renewable oil production technology, and we’re excited to be partnering with United on the first U.S. commercial biofuel flight.”

Solajet is made using microbial algae that grow in fermenters by feeding on sugars from plants. According to United, the biofuel meets the ASTM International specification for bio-derived aviation fuels, approved in July 2011 and referred to as “Hydroprocessed Esters and Fatty Acids” (HEFA) fuel. “HEFA fuels underwent rigorous testing and review by engine and airframe manufacturers, the U.S. military, the FAA and airlines. Solajet(TM), powering this United flight, met the certification requirements established by the ASTM and approved by the FAA.”

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