Lufthansa plans to begin using Neste’s sustainable aviation fuel blended with fossil jet fuel on flights departing from Frankfurt International airport.

The Finnish maker of renewable fuels says on 2 October that it delivered the first batch of the fuel to Lufthansa earlier this year.

“Neste and Lufthansa share the same ambition to increase the sustainability of aviation,” says Peter Vanacker, President and CEO of Neste.

The two companies began working together in 2011, when Lufthansa tested Neste’s biofuel on 1,187 flights between Frankfurt and Hamburg. The German flag carrier was the first airline to test alternative fuel on regular flight operations.

Neste says its aviation fuel is produced from renewable waste and residue raw materials, and is fully compatible with existing jet engine technology when blended with fossil fuels. The company adds that sustainable aviation fuel has up to 80% smaller carbon footprint compared to fossil jet fuel. In the US and Europe, the company’s renewable jet fuel capacity is currently 100,000 tons annually.

Earlier this year, Air BP began offering Neste’s sustainable aviation fuel to business jet customers at Stockholm Arlanda and Caen Carpiquet airports.

In September, Delta Air Lines said it is investing $2 million to research the feasibility of developing biofuel products from forest floor debris. Partnering with Northwest Advanced Bio-fuels (NWABF) in Washington State, the airline is studying alternative fuels as a means to help reach a goal of reducing carbon emissions 50% by 2050.

The broader aviation industry, which accounts for about 3% of global man-made CO2 emissions, has committed to similar goals under an ICAO-led framework called the Carbon Offsetting and Reduction Scheme for International Aviation. That effort calls for the airline industry to cap carbon output at 2020 levels and to cut emissions to half of 2005 levels by 2050.

Some industry observers, citing the projected expansion of air travel, have raised doubt about the industry’s ability to meet that goal.