What if we could use power plants to remove excess carbon dioxide from the atmosphere? This might sound far-fetched, but as a recent crop of carbon capture projects has proven, this could be the future of energy. Until recently, the idea of capturing carbon was widely considered an implausible way to reduce the world’s carbon dioxide emissions. However, many scientists today believe carbon capture technology will play an essential role in the race against global warming.
While most carbon capture systems are still in the experimental phase, a few have already become fully operational power plants. One plant in Iceland, operated by a startup company called Climeworks, has demonstrated the amazing ability to produce energy with negative carbon emissions. That means the plant actually removes more carbon dioxide from the surrounding environment than it produces. Let’s take a quick look at carbon dioxide capture and storage to understand how this is possible.
How the Carbon Capture Process Works
Researchers have been developing two distinct carbon capture methods: reversible absorption and direct air capture. Reversible absorption, the more common of the two methods, runs polluted air through a material called amine to absorb the CO2. Alternatively, direct air capture uses huge turbines to draw in exhaust from the power plant so that excess carbon dioxide particles can be extracted.
But where does all the carbon dioxide go? Once it is removed, power plants need a place to store it. Methods of carbon storage vary widely. In Switzerland, Climeworks operates a clean power plant that funnels into greenhouses, improving crop yields by 20 percent. Global Thermostat, a carbon capture project in Palo Alto, is working on a way to convert captured carbon dioxide into fuels.
Iceland’s Negative Carbon Emissions Plant
Unlike other carbon capture and storage projects, Climeworks’ power plant in Iceland generates geothermal energy, which is considered a clean energy source. Electricity is generated by pumping water through a series of underground pipes. Then, heat from deep underground turns the water into steam, which is used to generate electricity. The process emits a very small amount of carbon dioxide, which is where the carbon capture and storage process begins. Climeworks uses direct air capture to gather up carbon dioxide. The CO2 is then mixed with water and injected 700 meters underground. Finally, this mixture becomes trapped in basalt rock for millions of years.
The great news is that there are large basalt deposits all over the world, meaning that this carbon capture and storage process could someday be used on a large scale. The only drawback is that current carbon capture and storage technology isn’t cheap. Scientists in Iceland have managed to capture carbon dioxide and store it underground for only $30 per metric ton of carbon dioxide. But researchers working on other methods of carbon capture estimate that the process will cost at least $100 per metric ton, although when scaled up, some projects could drop down to $50 per metric ton. Only one carbon capture plant currently operates commercially: another Climeworks project in Switzerland.
Growing Interest in Carbon Capturing Technology
The Climeworks plants in Iceland and Switzerland are only two of many similar CO2 capture and storage pilot programs around the world. Other startup businesses in the U.S., Canada and British Columbia have received millions of dollars in private investments. Traditional energy companies are also experimenting with carbon dioxide capture technology. Exxon Mobil Corp. and FuelCell Energy have started a program in Alabama that aims to capture carbon dioxide from a combination of coal and natural gas emissions. ConocoPhillips, General Electric and RoyalDutchShell Corp. have all begun similar programs.
Jeffrey Bobeck is the lead policy analyst at the Global CCS Institute, an organization devoted to the advancement of carbon capture technology. He says that in order for carbon dioxide capture to be used on a large scale, researchers will need federal support. Bobeck has proposed increasing the 45Q tax credit, which incentivizes companies to participate in carbon storage programs. Whatever the solution, scientists and lawmakers need to act quickly. Combined with other clean energy technologies, carbon capturing could help halt global warming before the earth’s temperature rises to dangerous levels.