The venture capital arm of United Airlines will invest in Houston-based biotech startup Cemtiva Factory, which is attempting to develop a method to convert carbon dioxide into a source of sustainable aviation fuel (SAF).

United did not reveal the size of its investment.

United, which has set an ambitious goal of reaching net-zero emissions by 2050 without the use carbon offsets, is collaborating with Occidental Petroleum subsidiary Oxy Low Carbon Ventures (OLCV) in supporting Cemtiva. 

The companies said that together they will fund development work at the startup. If performance targets on the carbon dioxide conversion process are met, United Airlines Ventures and OLCV plan to form a joint venture to bring the technology to market. 

“This includes funding projects such as pilot and demo plants, engineering studies, financing construction and operating SAF plants,” United said. 

Cemtiva is just the latest company United is partnering with as part of its broad approach toward supporting green aviation projects. 

The carrier has also partnered with electric aircraft startup Heart Aerospace and electric vertical takeoff and landing, or eVTOL, startup Archer Aviation and has purchased an equity stake in hydrogen-electric engine developer ZeroAvia, which is working to develop zero-emission engines for regional aircraft. 

In addition, United has invested in carbon-capture startup 1PointFive, which is another Occidental subsidiary. And it is an investor in SAF producers Adler Fuels and Fulcrum BioEnergy, with which it has combined options to purchase up to 2.4 billion gallons of fuel. 

SAF is estimated to reduce lifespan emissions by 20% compared with kerosene-based jet fuel.