Technology to save the planet

• Carbon removal is a necessary technology to reduce climate damage.
• It’s controversial though in terms of its impact and use.
• Oil and gas use is particularly troublesome.

Plants are known for carbon removal, but they can’t work fast enough to compare repair the amount of climate damage for which humans are responsible on a powerfully ongoing basis.

In California, a startup’s open-air warehouse removes carbon dioxide from the atmosphere. Like trees but profitable, 40-foot-tall racks hold hundreds of trays filled with a white powder that becomes crusty as it absorbs carbon dioxide from the sky.

The company behind it, Heirloom Carbon Technologies, calls it the first commercial plant in the United States to use direct air capture. Another plant is operating in Iceland, and some scientists say the technique could be crucial to fighting climate change.

Heirloom will seal the gas it pulls out of the atmosphere permanently in concrete, which means it can’t heat the planet. Where that concrete will go, at present remains unclear .

Because nothing’s worth doing if it isn’t making money, the company is selling carbon removal credits to companies who pay a premium to offset their own emissions. Microsoft is one such company – it’s already signed a deal with Heirloom to remove 315,000 tons of carbon dioxide from the atmosphere.

Heirloom’s first facility in Tracy, San Joaquin, which opens on Thursday, is fairly small. It can absorb a maximum of 1,000 tons of carbon dioxide a year, which is the same as the exhaust of around 200 cars.

California. Feel free to do the math.

Which is just one reason why the company hopes to expand quickly: “We want to get to millions of tons per. Year,” says CEO Shashank Samala.

Once the stuff of sci-fi (and nature as we used to know it), the concept of sucking carbon dioxide from the air is being taken on by big business. Hundreds of startups are emerging. In August, the Biden administration awarded $1.2 billion to help several companies, including Heirloom, build larger direct air capture plants in Texas and Louisiana.

Companies like Airbus and JPMorgan Chase are spending millions of dollars on carbon removal credits in order to fulfil corporate climate pledges. Critics point out that many artificial methods of removing carbon dioxide from the air are wildly expensive, in the range of $600 per ton or higher, and some fear they could distract from efforts to reduce emissions. While there’s a way of dealing with emissions, what need is there to actually tackle emissions, after all?

It is an odd phenomenon, almost a “Get out of jail free” card, that lets companies essentially do whatever they wish, so long as they funnel money into a company that promises to absorb their emissions.

On the flipside, some say it’s essential to try. Nations have delayed cutting greenhouse gas emissions for so long, say scientists, that it’s almost impossible to keep global warming levels at a tolerable level unless emissions are cut sharply and also billions of tons of carbon dioxide are removed from the atmosphere. And that all has to happen by 2050.

Admittedly, that’s a task that planting trees can’t manage in time.

“The science is clear: Cutting back carbon emissions through renewable energy alone won’t stop the damage from climate change,” said Energy Secretary Jennifer Granholm, who planned to attend the opening of Heirloom’s facility.

“Direct air capture technology is a game-changing tool that gives us a shot at removing the carbon pollution that has been building in the atmosphere since the Industrial Revolution.”

How does carbon removal work?

The technology Heirloom uses hinges on one simple bit of chemistry: limestone forms when calcium oxide binds with carbon dioxide, a process that takes years in nature. Heirloom speeds it up.

At the California plant, workers heat limestone to 1,650 degrees Fahrenheit in a kiln powered by renewable electricity. Carbon dioxide is released from the limestone and pumped into a storage tank.

What’s left looks like flour, and is calcium oxide, that’s doused in water and spread over large trays, carried by robots onto tower-high racks and exposed to open air. Over three days, the powder absorbs carbon dioxide and turns back into limestone. Then, back to the kiln and the process starts over again.

“That’s the beauty of this, it’s just rocks on trays,” said Samala, who co-founded Heirloom in 2020. The hard part, he added, was years of tweaking variables like particle size, tray spacing and moisture to speed up absorption.

There is, of course, also the issue of a storage tank full of carbon dioxide. In California, Heirloom works with CarbonCure, a company that mixes the gas into concrete, where it mineralizes and can’t escape into the air.

In future projects, Heirloom also plans to pump carbon dioxide into underground storage wells.

The company won’t disclose its costs but experts estimate that direct air capture currently costs from $600 to $1,000 per ton. Heirloom’s long-term target is $100 per ton and the company plans to achieve that through economies of scale and mass-produced components.

For its next plant, planned in Louisiana, a more efficient kiln and a denser layout will cut Heirloom’s costs.

“We’ve seen this with solar panels, with gas turbines. As you deploy more, the costs come down,” said Julio Friedmann, chief scientist of Carbon Direct, a consulting firm. “There are lots of reasons to think it can happen here, too.”

The kilns run on clean power, which, in a different way from its fossilized alternative, is finite. In California, Heirloom paid a local provider to add more renewable energy to the grid to enable its energy-intensive process.

Experts say care is needed to ensure that direct air capture plants don’t inadvertently cause emissions from the electricity sector by diverting wind or solar power from elsewhere.

“If a company says it’s removing a ton of carbon dioxide, it’s important to make sure everything gets accounted for,” said Danny Cullenward, a research fellow with the Institute for Carbon Removal Law and Policy at American University. “That’s not always as easy as it sounds.”

Worth every penny

Wider access to direct air capture is important, but some companies are willing to pay a premium for it. Microsoft has a goal of carbon negative by 2030 and is Heirloom’s biggest customer.

Microsoft is doing everything it can to cut emissions, but it also wants to offset emissions from activities that aren’t so easy to clean up – things like the production of the cement it uses. It also plans to compensate for historical emissions.

Traditional offsets like paying for the protection of forests, Microsoft says, are difficult to verify and may not be permanent. Direct air capture seems more durable and – crucial to proving it’s made good on emission-cutting promises – measurable.

“Carbon removal can be a lot more expensive than offsets, but what you’re paying for in terms of climate impact is radically different,” said Brian Marrs, Microsoft’s senior director of energy and carbon.

The deal between the two companies marks one of the largest permanent carbon dioxide removal deals to date. The contract commits Microsoft to buying up to 315,000 metric tons of CO2 removal over a multi-year period.

Heirloom is laudable for publicly pledging that it won’t accept investments from oil and gas companies or use its technology to enable fossil fuel production.

Environmentalists are wary of oil companies investing in the technology, fearing it could be used to prolong the use of fossil fuels. Occidental Petroleum, an oil and gas giant, has emerged as a leading player in direct air capture.

The company’s CEO, Vicki Hollub, has said the technology could “preserve our industry,” an alarming statement in the ongoing battle against fossil fuels.

Occidental is building a different type of direct air capture in West Texas that can absorb 500,000 tons of carbon dioxide per year. The company plans to inject some of the gas into depleted oil wells to extract more crude, a practice known as enhanced oil recovery.

Occidental said emissions from the new oil would be offset by the injected carbon dioxide that remained underground, creating a carbon-neutral fuel that could be used in airplanes or ships that are difficult to decarbonize.

The oil proposal sparked a backlash: “There’s a big difference between exploring an infant technology to see if it can be developed, versus telling the public, ‘If we do this, we can continue burning fossil fuels forever,’” former Vice President Al Gore said at a recent New York Times event.

Emily Grubert, associate professor of sustainable energy policy at the University of Notre Dame, said that with billions of dollars rushing into carbon removal, it’s crucial to decide how big a role it should play in tackling climate change.

“Using direct air capture to offset large amounts of oil production is a completely different scale than using it to offset a few activities, like fertilizer use, where it’s impossible to cut emissions,” Grubert said. “And there’s a broad societal interest in figuring out what scale of carbon removal we’re committing to.”