Lipids and omega-3s are the building blocks to many foods and fuels. By making them out of waste carbon, LanzaTech CEO Jennifer Holmgren says, there’s now an opportunity to make a multitude of products—from nutritional supplements to fish feed to vegetable oil replacements to diesel fuel—without using up resources like land and water, and while simultaneously preventing more emissions from being released into the air.
LanzaTech already has a commercial plant running in China that turns carbon emissions from a steel mill into ethanol, which is then used to make fuel. The company intentionally set out to find a way to convert waste carbon into lipids and omega-3s, says Holmgren, because of all the things those molecules could then be used for. By making omega-3s, “that means you’re using CO2 to make nutrition,” she says. Omega-3 fatty acids are found abundantly in fish, and making them from waste carbon could help address overfishing in our oceans. Farmed fish are commonly fed smaller, wild-caught fish, “and the net impact of that,” she adds, “is that you’re actually fishing out our oceans with the purpose of making food for the farming of fish.” With the possibility of making the nutrients required for fish feed from waste carbon, there’s a future in which we can make that food without overtaxing our oceans.
The lipids—or fats—the process can produce are essentially vegetable oils. The abundant use of vegetable oils, especially palm oil, has a big environmental impact, with acres and acres of forests cut down to grow oil palm trees. With some modifications to the process, Holmgren thinks they can soon make lipids that can substitute for palm oil. Lipids that come from animal fats are also used to make diesel and jet fuel, and she thinks these lipids from waste carbon eventually meeting that need as well, without the land and water use and deforestation associated with animal agriculture.
The process works by feeding waste carbon and hydrogen to organisms that digest them and turn them into acetate. From there, an algae that normally eats sugar but is able to eat acetate turns that acetate into the lipids and Omega-3s. “A lot of things that eat sugar also eat acetate,” Holmgren says of microorganisms in our natural world. “I like to tell people that means acetate is the new sugar, except it doesn’t take land or water or anything else.”
Turning CO2 into ethanol happens through fermentation—microbes eat the waste carbon and produce ethanol. To make lipids and Omega-3s, though, there needs to be a source of energy inside the reactors. “In a world where making hydrogen from natural gas, this is probably not the best process,” Holmgren admits. “In world where we’re starting to [use] renewable electricity and electrolysis, then you’re going to make all that hydrogen from green electrons.” As this technology scales, she says, it’ll use, and benefit from, the growing renewable energy capacity.
The company’s ethanol production has already been put to real-world use: it powered a Virgin Atlantic flight from Orlando to London, and has been used in cleaning products made by Swiss company Mibelle. The lipids and omega-3 fatty acids are farther behind; LanzaTech is waiting to partner with other companies that can convert them into viable commercial products. Holmgren says that’s a next step as this pilot grows in scale which she estimates will take another four years (The company has been working on the process with India’s Department of Biotechnology for the past five years.) When it does scale, LanzaTech will be able to tackle climate issues from two sides: by preventing emissions from entering the atmosphere, and by creating products that no longer need to use up resources from our land or oceans. “Imagine a world where we could make all that stuff from CO2 in a reactor so you don’t have to impact land, water, biodiversity,” Holmgren says. “That’s the goal.”