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Next
month, the dream of carbon air capture will take
an important step toward reality as an
industrial facility in Iceland becomes the latest
of a growing number of projects to remove CO2 from
the air and put it underground. But – as Yale Envrionment 360's Jon
Gertner finds out – major hurdles, including
high costs, remain before this technology can be
widely deployed and play a key role in tackling
climate change.
In early September, at
a 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
mineralisation 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 utilised 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
US 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.” |
