Iceland review - 2019, Blaðsíða 102

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Iceland Review
A rough start
We’ve driven 30 minutes outside of Reykjavík to
Hellisheiði power station. Providing electricity and
hot water to the Reykjavík capital area since 2006,
it’s the world’s third-largest geothermal power plant.
It’s also the site of an important project in the global
fight against climate change: CarbFix. Since 2012,
CarbFix has been capturing carbon dioxide, dissolving
it in water, pumping it into the ground, and turning
it to stone, thus permanently removing it from the
atmosphere.
Geoscientist Dr. Sandra Ósk Snæbjörnsdóttir has
been working on research and development of the
CarbFix project since 2012. After watching a safety
video and donning helmets, goggles, and vests, she
takes us on a tour to show us the technology that’s
been reported on by the likes of the BBC and The New
York Times.
The seed for CarbFix was planted in 2006, the
same year the Hellisheiði power station activated
its first two turbines. “A professor from Columbia
University named Wallace S. Broecker held a lecture
here. He introduced the idea of using the natural pro-
cess which occurs when CO2 and basalt meet in order
to bind carbon dioxide,” Sandra tells us. “In 2007 the
project formally began.”
Our fist stop is a small, green building the size and
shape of a shipping container. “That was our first trial
lab,” Sandra tells us, “We call her Geirþrúður. We had
all kinds of adventures there while we were trying to
get this project off the ground.” First a gas-filtering
tower was destroyed, then frost damage impeded
progress. When the team was finally ready to pump
down the gases, some nearby road works blasted the
gas pipeline and the whole project came to a stand-
still. “The technicians that worked there never called
the lab Geirþrúður,” Sandra smiles. “They called her
Chernobyl.”
Finally, in 2012, CarbFix conducted its first exper-
iments pumping carbon dioxide into the ground. “We
started by pumping down only CO2, but then we did
experiments with a mix of hydrogen sulphide [H2S] and
CO2.” The reason for this is that when the power plant
was opened, it released much more hydrogen sulphide
than was expected. The gas caused all sorts of issues
such as damage to equipment and risk for workers
at the site. “On still days, there was a sulphur stink
in Reykjavík. There was a risk at one point that this
power station would lose its operating license.”
The CarbFix project has changed all that. “Now we
are binding around 70-80% of the hydrogen sulphide
from the power station, which is about 6,000 tonnes
per year, and are binding around one third of the
carbon dioxide the station produces, or around 12,000
tonnes per year. We’re tackling a local problem and a
global problem at the same time.”
Location, location, location
Hellisheiði has all the raw ingredients necessary for
applying CarbFix’s method: power, water, and abun-
dant basalt. “The Achilles heel of this method is that
you need a lot of water to pump down the gas.” That’s
no problem for Hellisheiði, which injects about 900
litres (240 gallons) of water back into the geothermal
reservoir per second. The CarbFix project is also able
to use the station’s existing injection wells for injecting
gas into basalt, eliminating the need for additional
drilling. “All we did was take two of the wells and add
a gas pipeline.” Sandra points to a small building,
roughly 8x8 metres and two stories tall, dwarfed by all
the huge structures around it. “This is the only build-
ing we had to add in order to capture our gas.”
In order for CO2-infused soda water to transform
into stone below the earth’s surface, it requires the
right type of rock. Luckily, Hellisheiði power station
sits on top of seemingly endless amounts of basalt, an
extremely reactive rock whose calcium and magne-
sium react with CO2 to form calcite. Another perk of
basalt: its porous structure can accommodate virtu-
ally limitless amounts of carbon. “Basalt is amazing,
“BASALT IS AMAZING,
IT’S LIKE A SPONGE.
YOU CAN STORE
A HUGE AMOUNT OF CO2
IN EACH SQUARE METRE.”