Ten ways to use carbon dioxide

The global supply of carbon dioxide could grow to thousands of times larger than it is today, if carbon removal grows as dramatically as the International Panel on Climate Change says is needed to reach net zero. 

And according to Julio Friedmann, chief scientist at Carbon Direct, all that carbon will either go into permanent storage or new products.

Speaking on Catalyst last week, he described the state of carbon capture today and the range of products that could use recycled carbon dioxide, from synthetic jet fuel to beer.

Today, the International Energy Agency estimates that about 45 large-scale commercial facilities worldwide capture an estimated 50 megatons per year. But to stay within IPCC targets, that 50 megatons of global capture will have to grow to several thousand megatons per year by 2050. 

So, what to do with that enormous pot of carbon? Friedmann offered up 10 options:

Geologic storage

Storage is likely to remain the biggest enterprise, Friedmann said. 

“It's also relatively cheap,” he said. “To turn CO2 into stuff usually takes energy or money. And so, in the same way we only recycle a fraction of our produced goods of any kind…we also will only recycle a fraction of the CO2.”

The cost of carbon storage varies widely, but more than half of onshore storage capacity is estimated to cost less than $10 per ton, according to the IEA. In comparison, the estimated cost of production of most products made from CO2 exceeds $1000 per ton, according to a report from Columbia University’s Center on Global Energy Policy co-authored by Friedmann.

Carbon dioxide pipelines are the cheapest way to transport the gas, but permitting remains a hurdle. The energy company Navigator, for example, in October canceled its midwestern carbon dioxide pipeline, citing “the unpredictable nature of the regulatory and government processes” after failing to secure permits from several state boards.

The upside of storage, however, is that there’s more than enough capacity: roughly 3,000 metric gigatons in the U.S. alone, according to the U.S. Geological Survey. For comparison, the IPCC estimates the world needs to remove up to 660 gigatons by 2100. 

Concrete

Concrete and cement already use carbon, but Friedmann said that those markets could use even more.

Even though only a fraction of concrete’s mass is carbon dioxide, the global construction market uses concrete in such large quantities that it could be a fruitful storage option.

“Every year the world uses 30 billion tons of concrete,” Friedmann said. “So turning CO2 into concrete is a gigaton market, and it's not nuts.”

Concrete is also attracting major interest from the U.S. Department of Energy, which announced $6 billion in grants to demonstration projects in hard-to-abate heavy industries, including concrete. The Columbia CGEP estimates that concrete’s carbon abatement potential, including both precast and ready-mix versions, is 344 megatons per year.

Aviation e-fuel

Meanwhile, in the face of upcoming regulations, airlines are buying up sustainable aviation fuels — including e-fuels made with electricity, hydrogen, and carbon dioxide.

“We are staring down the barrel of some very strong compliance requirements in aviation,” said Friedmann, citing the European Union’s ReFuelEU standards and the upcoming Carbon Offsetting and Reduction Scheme for International Aviation, which will become mandatory in 2027.

The scheme, governed by a United Nations agency, will require airlines to reduce net carbon emissions from most international flights.

But Friedmann said that even if all the planned sustainable aviation fuel plants come online, there still won't be enough low-carbon fuel to meet demand under these new regulations. Airlines could meet certain regulations, like CORSIA, with carbon removal, but Friedmann said that “the people who operate planes are disinterested in a deadweight economic cost.”

Instead, he added, many are also interested in owning the supply chain for e-fuels. Those airlines are saying “we would rather buy fuels that we understand the carbon content, where we might be able to source, where we might be able to invest and make money,” Friedmann added.

According to CGEP, the carbon abatement potential of jet fuel across all technological pathways is 2,667 megatons per year.

E-methanol

The shipping fuel methanol is another market that would use carbon. Maritime shipping accounts for about 3% of global carbon emissions, according to the International Council on Clean Transportation, and while different shipping routes require different fuels, methanol is one of the most prominent.

Like aviation e-fuels, e-methanol is made using electricity, hydrogen, and carbon dioxide. Major shipping companies, such as the Maersk spin-off CNX, are already investing in production. 

Friedmann predicted that CNX will shift from biomethanol e-methanol “when the technology is better, when the production lines are large, [and] when the costs are reasonable.” But as is the case for most low-carbon fuel production, producing e-methanol requires clean electrons.

That fact begs the question, Friedmann said, of whether we should instead be using that clean energy for other reasons: “And that's the point where it starts getting into questions of geography, infrastructure, markets, policy,” he added. 

Some geographies — like Kenya, with its abundant wind, solar, and geothermal power — may be better suited to e-methanol production than others. 

“Unsurprisingly companies are starting to scramble; countries are starting to scramble,” Friedmann said. “They want to get the market share for the production. They want to get the market share for the manufacturing. They want to get the market share to monetize their renewable resources.”

CGEP estimated the carbon abatement potential of methanol across all technological pathways is 1,338 megatons per year.

Urea

Other chemicals, such as urea — an agricultural fertilizer with a $191 billion market today — could also become major end-uses for recycled carbon dioxide. 

Friedmann said that turning carbon dioxide into urea is “super cheap and easy to do.” He cited the Saudi Arabian chemical company SABIC as an example of a company that is already recycling fossil carbon dioxide and producing urea from it, ultimately reducing the footprint of the facility.He cautioned that the urea market is likely to “saturate pretty quickly,” but in the near-term is an attractive option nonetheless. 

CGEP found the carbon abatement potential of urea to be 138 megatons per year.

Ethylene

But using carbon in ethylene, a feedstock for plastics, is “wicked hard” in comparison, Friedmann said. That’s in part because ethylene is already very cheap, and green ethylene would likely struggle to compete on its own.

Companies are doing so anyway because “the technology is straightforward,” he added. “A company like Dow — they might not want to do this automatically, but they surely know how to do this.”

Friedmann sees it as just a matter of time before green ethylene is added to these chemical giants’ suite of energy transition activities, alongside carbon capture, green hydrogen, and electrification. 

Meanwhile, other companies like Lanzatech are actually using biotech — “the genomes of bugs — to develop products like ethylene.

“It's not an electrical pathway, but it's a really smart pathway,” Friedmann said. “They're using the natural world re-engineered to do this job.”

The carbon abatement potential of light olefins including ethylene across all technological pathways, CGEP found, is 3,259 megatons per year.

Syngas

Running carbon dioxide through a Fischer Tropsch process turns it into syngas, a mix of carbon monoxide and hydrogen. Syngas can be used for producing other fuels like diesel and methanol, as well as chemicals like ammonia.

Friedmann explained that syngas is attractive to governments that have existing infrastructure that can make use of it.

For the German government, for instance, a major question in the energy transition is what to do with the potentially displaced workers who have historically worked in natural gas. They’re wondering, Friedmann said, ”what are we going to do with these assets? What are we going to do with our chemical manufacturing?”

Rather than offshoring those capabilities to a cheaper place, recycling carbon to make syngas offers an option to keep jobs, revenue, and intellectual property within a country’s borders.

CGEP said the carbon abatement potential of syngas across all technological pathways is 2,894 megatons per year.

Material swaps: Polycarbonate and carbon fiber

Another option, which is “a little big over the horizon” in Friedmann’s eyes, is material substitution: swapping commonly used materials with alternatives made using recycled carbon dioxide.

For instance, polycarbonate is a potential substitute for glass, and carbon fiber is a potential substitute for steel rebar in construction projects.

The challenges for these material swaps, though, include both the high cost of production for alternative materials and low margins in commodity markets. 

“It's hard to make a lot of money or business doing [swaps],” Friedmann said. “But you have an existing market if you can get the off-takes — if you can get people to buy the green premium.”

The upside of material substitution, he added, is the simplicity of the approach, if not the technological innovation required. He described it as challenging and “not necessarily cheap or easy,” but straightforward.

The Center on Global Policy report did not analyze material swaps.

Coming soon: Graphene

Finally, Friedmann described a much less immediate “Marvel Cinematic Universe future where everything's made out of carbon composites.” To Friedmann, that world is not outside the realm of possibility, just “farther away and harder.”

An example from that world: graphene.

“Graphene is a super structured, superlight, super durable, super electrically conductive material,” Friedmann explained. “It's like a version of buckyballs, basically.”

Graphene is currently being made in labs, but in very small quantities. But if new technology enables more production, it could be used in novel applications. In fact, graphene has conductive properties that might make it valuable on the power grid.

Friedmann said there is exploration of whether an advanced, carbon-based material like graphene could ultimately replace old copper wires. Friedmann predicted that the potential prize for these kinds of novel materials is big, to the tune of $100,000 per ton for anyone who can pull off making them.

“They're hard to make, but boy are they valuable,” he said. 

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