Is green jet fuel cooked in bioreactors in Texas?

Porto Alegre (Brazil)In a discreet laboratory complex in Houston, Texas, the company Cemvita attempts to redefine the meaning of "fossil fuel." Its founder and scientific director, Tara Karimi, assures that its objective is simple but radical: "Transform carbon dioxide and industrial waste into high-value products, such as fuels, fertilizers, or cosmetics."

ARA was able to speak in the city of Porto Alegre (Brazil), within the framework of the events of Caldeira Week, to which the newspaper was invited by the Caldeira Institute, one of the hub Cemvita, founded in 2017 by Karimi and his brother Moji, has developed a biotechnology platform called FermWorks, capable of making microorganisms specifically designed for this function convert CO₂ or organic waste into what they call what they call FermOil, a base oil that can be used to make aviation fuel, detergents, or creams. "Our process involves zero deforestation and can produce various types of products. The oil we produce can be used not only for fuel, but also in personal care or cleaning products," explains Karimi.

To date, their most ambitious venture has been in the field of sustainable aviation fuels (SAF), an emerging market driven by pressure on the industry to reduce its emissions. In 2023, United Airlines signed a twenty-year contract with Cemvita to supply it with 50 million gallons of alternative fuel annually. "Our product has five times fewer carbon emissions than the current SAF on the market because we start the process from carbon dioxide. We turn the problem into a raw material," says Karimi, who assures that he is also in contact with European airlines to develop similar programs.

All in all, Cemvita's scientific methods, based, as suggested, on synthetic biology to convert CO₂ into fuels and chemicals, are innovative but still highly experimental. Despite their potential to reduce emissions, their viability on an industrial scale is uncertain and depends on still-high energy and economic costs. Furthermore, the genetic manipulation of microorganisms raises questions about safety and environmental control. In any case, Cemvita offers a disruptive vision, but it needs independent validation and transparency of results to establish itself as a real alternative to petroleum.

Economic viability?

The business model is not only based on technology, but also, necessarily, on economic viability, even more so at a time when the President of the United States repeats the slogan, "Drill, baby, drill! as if climate change weren't a problem. "From the beginning, we wanted to have a self-sustaining business, without depending on public funds or additional loans. That's why we decided to start with waste. If you use a waste stream, you drastically reduce production costs," explains the co-founder. The result is a product that, in her words, is already cheaper than conventional SAF, because it doesn't start with much more expensive raw materials such as soybean oil or sugarcane.

Cemvita's differential value also lies in its ability to create several lines of business from the same process. Approximately 30% of the initial waste is converted into oil; the rest is used for biofertilizers and biostimulants used in reforestation or regenerative agriculture. "Our process produces two products and generates virtually no waste. What's left is used to improve soils and restore biodiversity," says Karimi.

This approach "nature positive"Nature-positive" is a central part of the business philosophy of the two brothers at the helm of Cemvita. "We don't just want to reduce emissions; we want to have a positive impact on biodiversity and the environment," he emphasizes. This vision has also been translated into their international expansion strategy: Brazil has been one of the first destinations chosen for production outside the United States. "In our plan, all the core values are based on sustainability. And we see that these values are well established in Brazil. The country has a consolidated infrastructure in biomanufacturing and the circular economy, with successes in biofuels such as bioethanol and biodiesel," he comments.

For Karimi, the key is to build on what already works. "Let's start in a country that has a history of success and an existing infrastructure. We add value: we're not here to replace anything, but to complement and improve what already exists." The company is also committed to collaborating with local suppliers to reduce dependence on imports and strengthen the development of local scientific talent. "We want to work with local suppliers and take advantage of existing talent. All we need is additional training to adapt it to our technology," it states.

Cemvita's future now lies in scaling up industrial production. The company plans to produce up to 500 barrels of sustainable oil per day in its first commercial plant, while maintaining a minimal environmental impact: "99% less land and water use compared to traditional production. This industrial capacity is what can turn a laboratory innovation into a real alternative within the global energy market."

All of this places it as one of the biotechnology companies with the greatest potential within the climate sector. In 2025, Cemvita has been recognized by the Greentown Labs consortium as "Climate Impact Startup of the Year." It's no small distinction: the industry already sees her model as one of the most promising ways to decarbonize difficult sectors like aviation and petrochemicals. Tara Karimi summarizes her philosophy in a single sentence that encapsulates the revolution she wants to foster from Houston: "Sustainability isn't a luxury, nor a cost. It's a business.