SF Technotes

Trapping a Greenhouse Gas in Rock

By Michael Castelluccio
October 26, 2017
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CO2plant_credit

As part of a plan to expand its solution to unlock a negative emissions future, Swiss cleantech company Climeworks announced on October 10 the opening of a new plant in Hellisheidi, Iceland, that will combine DAC (direct air capture) technology with safe, permanent geological storage of the global-warming CO2 gas in our atmosphere. This is the second installation for Climeworks, and it represents a joint effort with researchers at the Icelandic Project CarbFix.

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The new plant will use a highly scalable carbon-removal technology to draw CO2 out of massive volumes of air and then inject the gas into underground basalt rock formations. Within the underground formations, the gas will solidify into carbonate minerals in fewer than two years. The press release explains, “This type of solution has been recognized as a crucial component in efforts to achieve global warming targets.”

 

Although the process has been theoretically possible, it just hasn’t been practical until recently. Two problems are inherent in the extraction/geological storage solution. Most researchers assume that the time needed for the stored CO2 to turn to stone would be measured in hundreds of thousands of years. Also, concentrations of CO2 molecules in the atmosphere are so widely dispersed that trying to collect enough of them to make the process worthwhile would be problematic.

 

Despite those two serious stumbling blocks, Climeworks opened its first DAC plant in Hinwil, Switzerland, in June 2017. Built on the roof of a waste-incineration plant, large fans pulled air into the module and through its filters. The CO2 that was captured was actually sold to a local farm, where it was used in greenhouses to accelerate photosynthesis for tomato and cucumber plants. With a contract for 900 tons of CO2 per year, Climeworks became the first to make money, not spend it, to cool the planet.

 

The new Hellisheidi plant in Iceland (see photo above) has two additional advantages. One is related to very favorable underground basaltic formations (igneous rock common in volcanic regions), and the other is the CarbFix technology already in place at the Reykjavik Energy geothermal power plant there. The Swiss inventors installed their seven-foot-tall powerful fans and filter systems over an ideal infrastructure already in place.

 

HOW IT WORKS

 

The project leader at the Hellisheidi power plant, Edda Sif Aradottir, describes a seven-step process for the new DAC plant:

 

  1. “The Climeworks DAC module captures CO2 from ambient air.
  2. The CO2 binds to our patented filter.
  3. Once the filter is saturated with CO2, it is heated by low-grade waste heat from the geothermal plant.
  4. The CO2 is released and bound to water.
  5. The carbonated water is pumped more than 700 meters (2,296 ft.) underground.
  6. Here, it reacts with the basaltic bedrock, forming solid minerals.
  7. A permanent, safe and irreversible storage solution is created.”

 

Photo: Climeworks
Photo: Climeworks

 

 

On the company’s website, Climeworks engineers summarize the process: “The CarbFix2 project imitates natural processes and speeds them up rapidly. The potential of scaling up our technology in combination with this effective CO2 storage is enormous: it unlocks possibilities in Iceland and numerous other regions in the world where there is a similar geological foundation of basalt.”

 

Photo: Sandra Snaebjornsdottir
Photo: Sandra Snaebjornsdottir

 

 

And they conclude with a very optimistic prediction. “This partnership is helping to realise our mission to capture 1% of global emissions by 2025.”

 

The Chemical Engineer noted some more specific numbers and conditions of the process. The amount of CO2 that can be captured at the plant is 135 kg/day, and the amine-loaded filters can be used for several thousand cycles by heating them. The water doesn’t have to be fresh—seawater or even wastewater can be used. The engineers also point out that basalt is found in various places around the world, including, India, the United States, Russia, and under ocean floors. Aradottir says that theoretically “there is enough basalt in the world to mineralize all the CO2 from all the fossil fuels being burned on earth.”

 

POLITICAL SOLUTIONS ARE WOBBLY

 

Jan Wurzbacher, one of the cofounders of Climeworks, says the new Icelandic installation will be able to operate nonstop and will vacuum about 50 tons of CO2 from the atmosphere each year. “We’re insurance as the going gets tough. The world will need affordable machines that can recork the CO2 genie on massive scale, render it usable or harmless in storage.”

 

Wurzbacher’s partner Christoph Gebald has commented to the media on the perpetual wrench in the works: “Our biggest headache planning ahead is second-guessing politicians. Political support for climate protection is prone to wobble. Even so, we’re witnessing an independent private-sector drive to curb CO2 that’s resilient to politics. We’re counting on a big role for Climeworks in the emerging carbon economy.”

 

In an article for Quartz, Akshat Rathi explained that, despite the very modest productivity of the pilot program, air capture still matters for two reasons. “First, we currently don’t have any possible way to deal with CO2 released by cars, ships, and planes. Second, because we are on track to emit more CO2 than we need to keep under the 2°C limit, we likely need a means of sucking back up some of that extra greenhouse gas.”

 

He offered a visual chart that attached some numbers to the “wobble” of the planning by some nations.

 

Photo: University of Manchester
Photo: University of Manchester

 

 

The chart shows the historical emissions in gray and then projects emission targets that are required if we are to reach climate goals. Unfortunately, “approximate emission pledges” made in the Paris climate agreement show our emissions increasing, when they should be decreasing (following the trajectory shown in red on the chart).

 

What began as Gebald’s master’s thesis in engineering is now the first “negative emissions” plant in the world—one that takes in more carbon than it uses. Many are skeptical about the ultimate goal of capturing 1% of global emissions by 2025, but the fans are spinning, and streams of carbonated water are being injected into the ancient layers of lava almost a half-mile beneath the Icelandic landscape.


EDITOR’S NOTE: Although chemical engineering might seem a little off the digital pathways we usually travel in this blog, the technology covered in today’s story, if successful, will have a significant impact on manufacturing, energy, and transportation industries. In the same week that Climeworks announced its work in Iceland, the U.S. Department of Energy announced partnerships between nine American corporations, including GE, Ingersoll Rand, and Trane, and nine Chinese corporations to begin early-stage research and development of energy efficiency and renewable energy technologies.

 

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Michael Castelluccio has been the Technology Editor for Strategic Finance for 21 years. His SF TECHNOTES blog is in its 19th year. You can contact Mike at mcastelluccio@imanet.org.


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