The cheapest way to permanently sequester carbon involves ... fizzy water
In this episode, Ólafur Teitur Guðnason of Icelandic company Carbfix discusses his company’s approach to carbon sequestration by essentially making fizzy water and burying it deep underground.
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Text transcript:
David Roberts
The idea behind the Icelandic company Carbfix is simple: pack water full of carbon dioxide (literally carbonate it, like a SodaStream) and inject it deep underground into Iceland’s porous basaltic rock. Minerals in the rock dissolve in the water, where they react with the CO2 to become calcium carbonates.
The carbon effectively becomes rock, which it will remain, for all intents and purposes, permanently. Or at least thousands and thousands of years. It is as long-term as carbon sequestration gets.
The idea dates back to 2006, but pilot injections didn’t begin until 2013 and it wasn’t until 2016 that a study published inScience confirmed that 95 percent of the CO2 in the water was mineralizing within two years — far faster than most had assumed possible.
Since it started, Carbfix has sequestered almost 100,000 metric tons of CO2 at its original site, but that is just a drop in the bucket compared to what it believes is possible. It has plans to make Iceland a major international carbon-burial hub and to replicate its technology in other geographies, maybe even in the shallow ocean.
When I visited the Carbfix operation in October and saw it in action, I was extremely intrigued and had a million more questions, so last week I got in touch with Ólafur Teitur Guðnason, Carbfix’s head of communications, to talk about where the company gets the CO2 it buries, where it plans to get it in the future, whether burial can work in other kinds of rocks and geographies, and exactly how much carbon Iceland can store.
All right, then, with no further ado, Ólafur Teitur Guðnason of Carbfix. Welcome to Volts. Thank you so much for coming.
Ólafur Teitur Guðnason
Thank you so much for having me.
David Roberts
So, Ólafur, I visited you guys when I was out in Iceland a few weeks ago and was very taken with this idea. And I don't know how I have been covering this stuff for so long without ever hearing about it, but it sounds like you guys are sort of on the verge of expanding. So I think probably a lot more people are going to be hearing about you soon. So to begin with, for listeners who are not familiar with your company, I'm going to run through the process and tell me if I get anything wrong. So you get a source of water, and we can discuss the source of water more later.
But you get water, you carbonate it more or less like a SodaStream carbonates water. You pump carbon dioxide into the water, and then you pump the water deep underground. And this carbonated water is heavier than normal water, so it tends to sink down to the bottom of the water table. And as it is sinking, the carbon dioxide in the water reacts with minerals in the rock to form calcium carbonates. Basically, the carbon dioxide in the water gets transformed into a form of rock, where it will then stay underground as rock for thousands of years. So you've permanently sequestered the carbon.
Is that more or less an accurate description?
Ólafur Teitur Guðnason
It's more than more or less accurate, I think. I'll give you a ten out of ten.
David Roberts
Excellent. Good. Well, I have so many questions about this, but the one thing I wanted to start with is the carbonation process of the water. Is that your intellectual property here? Is that your sort of main thing that you've pioneered here as a different way of carbonating water, or is there something specia
