2018 Update: Scientists at Rutgers University have developed catalysts that can convert carbon dioxide into plastics, fabrics, resins and other products. According to a study published in the journal ‘Energy & Environmental Science’ in November 2018, the electrocatalysts are the first materials, apart from enzymes, that can turn carbon dioxide and water into carbon building blocks containing 1, 2, 3 or 4 carbon atoms with more than 99% efficiency. The products that the scientists created could be used as precursors for adhesives, plastics and pharmaceuticals.
With the Internet abuzz with news of the effects of global warming, climate change, and the huge carbon footprints of certain countries, positive news related to curbing these hazardous phenomena feels like a miracle. One such piece of news came straight out of Iceland a few days ago.
For the first time in the history of curbing carbon dioxide emissions, scientists have figured out a safe way to capture the detrimental gas. They have successfully captured carbon dioxide emitted from a geothermal power plant, pumped it underground and then converted it into stone!
Dealing with carbon dioxide emissions
Carbon dioxide emissions from power plants and other industrial sources is the leading contributor to global warming, so it holds top priority on the list of things we need to deal with to control and mitigate the effects of global warming, which is leading to rapid climate change around the globe.
Carbon Capture and Storage (CCS)
One of the ways we deal with carbon dioxide emissions is to capture and store them. This technique is called carbon capture and storage (or carbon capture and sequestration).
This process basically involves obtaining waste carbon dioxide from a source and then transporting it to a site where it can’t enter the atmosphere. The most common site for storing this waste carbon dioxide is underground (sometimes, they also pump it underwater into oceans). Now, a treasure chest buried deep underground might never be found, but it’s not so simple in the case of gases like carbon dioxide. Sure, you can store it underground, but there is always a risk of it leaking back out into the atmosphere.
Needless to say, such a scenario could be even worse, as the gas would pollute the atmosphere anyway (which it would have done if you hadn’t pumped it underground in the first place), only you would have futilely spent millions of dollars to fund the procedure of pumping the gas underground.
There have been some attempts in the past that involved injecting carbon dioxide into sandstone soil or deep saline aquifers, but those haven’t been very successful, as these attempts relied on layers of impermeable capping rocks to hold carbon dioxide down, increasing the risk that the gases would leak.
What’s so special about the Hellisheidi power plant ?
Within the Carbfix Project at the Hellisheidi plant, they have managed to solidify carbon dioxide, thus nearly completely eliminating the risk of its leakage.
According to a paper published in Science, researchers working at the Hellisheidi geothermal power plant (Reykjavik, Iceland) were able to pump the carbon dioxide-rich volcanic gases emitted by the power plant into deep underground basalt formations, mix them with water and chemically solidify the carbon dioxide, essentially turning it to stone.
They combined water with the waste carbon dioxide gas to make a slightly acidic solution that was subsequently pumped hundreds of meters underground into the volcanic basalts that compose a major portion of the North Atlantic island. This mixture then reacts with the magnesium and calcium ions found in basalts to form magnesium and calcium carbonates, respectively.
Basaltic rocks can be found on every continent, which is good news for the usefulness of this technology. According to Dr. Matter, “In terms of the availability of basaltic rocks to take care of carbon dioxide emissions globally – no problem.”
In order to test that the mixture they injected underwater didn’t leak, they tagged it with a tracer chemical (carbon-14, a radioactive form of the element), which helped them ascertain the mixture’s position. Juerg Matter, from Southampton University and the lead author of the study, reports that, “Of our 220 tonnes of injected CO2, 95% was converted to limestone in less than two years.”
An incredibly fast process
Not only did the idea of solidifying carbon dioxide work well, but the speed at which the entire process occurred at the Hellisheidi plant was also impressive.
Scientists had feared that the process might take hundreds or even thousands of years to accomplish, but this amazing process occurred in less than 2 years. “It was a huge surprise to all the scientists involved in the project, and we thought, ‘Wow! This is really fast,'” Dr. Matter stated.
…even the conservation of the environment.
Unfortunately, the entire procedure requires a lot of money, as the infrastructure required to pump the waste gas underground is quite expensive. Furthermore, the process requires an awful lot of water. Consider this: out of the mixture that’s pumped underground, waste carbon-dioxide forms only 1/20th of it. Apart from that, researchers also believe that there have to be more field-scale tests (like the one in Iceland) in different parts of the world to better understand the applicability of the technology in different environmental and geological conditions.
Notwithstanding the pitfalls, this novel method undoubtedly marks a great step in the technology of carbon capture and storage, as well as the conservation of the environment; it gives us a bit more reassurance that the planet can still be salvaged with the help of technology and a better understanding of nature’s incredible forces.