Project Removes Atmospheric Carbon Dioxide for Permanent Fixation

by admin on September 11, 2021

Climeworks “OCRA” Facility in Iceland for CO2 Removal from Air

The Dream of Carbon Air Capture Edges Toward Small-Scale Reality

From an Article by Jon Gertner, Yale Environment 360 News, August 25, 2021

Next month, an industrial facility in Iceland will join a growing number of projects to remove CO2 from the air and put it underground. But major hurdles, including high costs, remain before this technology can be widely deployed and play a key role in tackling climate change.

Early this September, at an industrial facility located about 25 miles southeast of Reykjavik, Iceland, the Swiss company Climeworks will mark the opening of a new project named “Orca.” At least in a conventional sense, Orca doesn’t actually make anything. It is comprised of eight elongated boxes that resemble wood-clad tanks. Each of these boxes — known as “collectors” — is roughly the size of a tractor trailer, and each is festooned with 12 whirring fans that draw a stream of air inside. Within the collectors, a chemical agent known as a sorbent will capture CO2 contained in the air wafting through.

Periodically, the surface of the sorbent will fill up. And at that point the CO2 trapped within it will need to be released. At Orca, this task is accomplished with a blast of heat, which is sourced from a nearby hydrothermal vent. The extracted CO2 will then be piped from the collector boxes to a nearby processing facility, where it will be mixed with water and diverted to a deep underground well.

And there it will rest. Underground. Forever, presumably. The carbon dioxide captured from the Icelandic air will react with basalt rocks and begin a process of mineralization that takes several years, but it will never function as a heat-trapping atmospheric gas again.

Climeworks maintains that Orca, once it’s running around the clock, will remove up to 4,000 metric tons of CO2 from the atmosphere each year. And there isn’t much reason to doubt the facility can achieve this feat. For one thing, the technology for the plant, known as direct air capture, or DAC, is a variation on ideas that have been utilized over the course of half a century in submarines and spacecraft: Employ chemical agents to “scrub” the excess CO2 out of the air; dispose of it; then repeat. More to the point, perhaps, is the fact that Climeworks has already built smaller, less sophisticated plants in mainland Europe, which have in turn pulled hundreds of tons of CO2 per year from ambient air.

What seems most significant about Orca, then, is how it represents the possibility that direct air capture has moved closer to something resembling a commercial business. Climeworks now has dozens of customers — individual consumers who have purchased carbon removal services directly from the company, as well as corporations, like the insurance giant Swiss Re — who will pay for the permanent carbon offsets that will be buried underneath Icelandic soil. What’s more, the Orca facility will be the largest functioning direct air capture plant in the world to date — by the company’s estimation, it represents a “scale-up” of its carbon removal efforts by about eighty-fold over the course of four years.

And yet, Climeworks and Orca will likely soon be eclipsed. Plans for even larger DAC plants — one in the U.S. Southwest, slated for completion at the end of 2024; another in Scotland, to be finished about a year after the American project — will be built by a competitor, Carbon Engineering, of British Columbia. Employing a somewhat different technology, Carbon Engineering’s facilities, as initially planned, will be powered by renewable energy and will eventually each remove, on net, about a million metric tons of carbon dioxide a year from the atmosphere.

“In our view, this will decisively answer the question: Is direct air capture feasible at large scale and affordable cost,” Steve Oldham, the CEO of Carbon Engineering, told me recently. “As I see it, we are out of academic research and feasibility and now into engineering reality.”

One way to consider the global value of these efforts is to place them within the humbling math of climate change. In the most recent report by the Intergovernmental Panel on Climate Change (IPCC), a number of models were used to chart possible future emissions scenarios, and to make sense of how we might experience a rise of, say, 1.8 degrees C or 2.5 degrees C (3.2 degrees F to 4.5 degrees F) by the year 2100.

Last year, about 31 billion metric tons of carbon dioxide were released into the atmosphere. Probably that number will rise even higher this year, as the global economy begins to recover from the COVID-19 pandemic. But to have a chance at limiting warming to 2 degrees C we would have to effectively bring our emissions near to zero by around the middle part of this century.

Without question, the best way to begin doing so is to drastically transform our electrical, transportation, and industrial systems to emissions-free energy sources and processes. However, we may need to actively compensate for economic sectors — air travel, for instance, or steel production — that prove too hard to rapidly decarbonize. This would mean we would have to actively take CO2 out of the atmosphere at the same time. Our carbon removal efforts could involve natural means, such as sequestering atmospheric CO2 in soil or new forests. But we could also utilize more technological approaches, such as DAC or bioenergy with carbon capture and storage — known by the acronym BECCS—which involves growing plants, burning or fermenting them for energy, and then capturing the CO2 emissions and burying them.

And here the numbers get daunting. Zeke Hausfather, a climate scientist at the nonprofit Berkeley Earth involved in charting possible emission pathways for the IPCC report, told me that in one of the most optimistic scenarios, which limits temperature rises to 1.5 degrees C by 2100, the conditions require massive mitigation efforts as well as about 17 gigatons — that’s billions of tons — of CO2 removal per year by the end of the century. And as much as planting trees might seem an ideal solution to help us reach such a goal, new forests are likely not a sufficient or durable carbon removal solution, especially in the wake of huge wildfires in Siberia and the American West. “Natural ways of removing CO2 are generally less desirable than long-term geologic storage through BECCS or DAC,” Hausfather says, adding that this is because storing carbon above ground in biomass is most likely temporary.

Whether DAC can make a meaningful contribution to carbon removal goals remains a lingering question. But the new Climeworks and Carbon Engineering plants suggest significant progress, not just hype. “You’ve got these two companies that are ready to go today,” Jennifer Wilcox, an official at the U.S. Department of Energy (DOE) and an expert in carbon capture technologies, told me. “But the question is, how do they get from thousands of tons to millions of tons?’” After that, of course, comes an even bigger question: Could they actually get to billions?

The full Article can be found at Yale E-360 here:

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