The exploration of capturing carbon in rocks and coping with climate change

One night at In November 2016, Gebald participated in a grand party organized by philanthropist Laurene Powell Jobs in Marrakech. He felt a little out of place among her guests. A group of famous climate researchers, activists, and policy makers all attended the COP meeting in the city, which was a major annual event in the climate community. Dutifully patrolling around, he met a sociable man with white hair with thick curly hair. It is the newly retired Icelandic President Ólafur Ra​​​gnar Grímsson. Gebald told him the story of Climeworks. “This is wonderful!” Gebald recalled Grímsson’s words. “I can store CO₂ Underground in our country. But we have always lacked the technology to capture it. “

Grímsson is talking about Carbfix, a publicly-owned subsidiary of Reykjavik Energy, which is developing a system to store carbon by injecting it into underground geological formations. Reykjavik Energy also happens to operate several beautiful, clean geothermal power plants. Grímsson made some introductions, and soon after, Gebald and Wurzbacher finalized a partnership with Carbfix.

Icelandic officials may have been very welcome, but Iceland itself is not so popular. In 2017, Wurzbacher and Gebald built a small experimental plant with a single intake fan near Helisheidi, but soon “it really froze,” Gebald said. One day, when the temperature dropped below zero, steam from a geothermal power plant hit the bare metal of the machine and was covered with ice. On another occasion, a huge storm almost took away the entire multi-ton structure. “We had to fix it to the ground,” Gebald said.

Four years later, after many failures, Climeworks’ new factory, called Orca (orcas and the word “energy” in Icelandic), went online. It is located on a verdant volcanic plain, just a short drive from the visitor center where the opening ceremony was held. Eight olive-green container-sized steel boxes stand on concrete risers and are connected to the white low-rise building that serves as the control center through elevated pipes. Steel container, called CO₂ Collector, in front is a big black fan, sucking in the air river.

In the collection box, the air flows through a filter coated with amine-based adsorbents and other materials that can capture CO₂ molecular. The carbon eventually saturates the filter, just like a sponge absorbs water.At that time, the sliding door seals the air inlet, and hot air enters from the control center through the pipe, heating the filter to about 100 degrees Celsius, thereby releasing carbon dioxide₂The vacuum then pulls the free-floating molecules to the control center, where sparkling tanks, pipes, and other hardware compress the gas. Then it was transported to several igloo-sized geodesic steel domes a few miles away, squatting on the plain, like an emergency shelter for Martians.

Carbfix technicians and machines handle the next steps. Inside the dome, a powerful motor pushes the incoming water flow into the injection well.company₂ The pipe pours the gas into the water. “This is an underground SodaStream!” said Sandra Snæbjörnsdóttir, a Carbfix scientist with shoulder-length brown hair and serious green eyes, wearing tortoiseshell glasses, who helped design the system. At a few hundred meters, the sparkling water flows into the ground, where it reacts with basalt deposits and turns it into solid minerals. In other words, the warming carbon gas turns into stone, just like the villain in a fairy tale. “This is essentially the way nature stores carbon dioxide₂,” Snæbjörnsdóttir said. This strategy has enough room. Worldwide, there may be enough suitable geological formations to store trillions of tons of carbon.

At the most basic level, the system will do what it is supposed to do: Climeworks extracts carbon from the air, and Carbfix bury it in the ground. They all use geothermal power to generate electricity and only produce a small amount of greenhouse gas emissions. But the capture part is still very energy consuming and therefore expensive. Of course, fans need electricity, but most of the electricity is used to heat the carbon to release it from the adsorbent.