One thing is becoming clear: What we are doing isn’t working. In April of this year, the level of carbon dioxide (CO2) in the atmosphere was 410 parts per million (ppm). The last time CO2 levels were over 400 ppm was during the mid-Pliocene era 3 to 5 million years ago. Despite moves to renewable energy and attempts to improve efficiency, the global manmade output of carbon dioxide (CO2) was a record-setting 32.5 gigatonnes in 2017—a 1.4 percent increase over the previous year. The rise was due to a 2.1 percent increase in global energy demand, with 72 percent of that demand met with fossil fuels.
The Wrong Direction
It’s not like we aren’t trying. Switching from coal to natural gas for electricity production has helped, along with the spectacular growth in solar energy worldwide. Electric vehicles haven’t made much of an impact yet (with around 1% of the new car market). But they are poised to increase significantly during the next decade. However, the numbers are still going in the wrong direction. Temperatures are rising about 0.2°C per decade and will increase by more than 1.5°C by 2040, compared to 2015, according to a recent UN draft report.
If what we are doing hasn’t worked, it’s time to try something different. Several efforts are underway to develop technologies that will pull CO2 directly out of the atmosphere. It’s something that plants do every day. Photosynthesis combines CO2 from the atmosphere with water and energy from sunlight to create sugars, starches, and other useful organic materials while releasing oxygen back into the atmosphere.
Yet we have unbalanced the system by dumping unimaginable amounts of CO2 into the Earth’s atmosphere by burning fossil fuels over the past 150 years. In addition, deforestation is removing 18.7 million acres of forests annually—clearing an amount of land for housing and animal grazing that is the equivalent of 27 soccer fields every minute, according to the World Wildlife Fund (WWF). If we are placing plants in a position where they cannot keep up, then maybe we can build machines to remove enough CO2 to make a difference.
Take The Prize
That’s the idea behind the NRG COSIA Carbon X-Prize. It’s a $20 million global competition to create breakthrough technologies to convert CO2 emissions from power plants into useful things like building materials or even alternative fuels. The competition started in 2015. At this point, there are ten finalists whose ideas are being tested on a large scale at facilities adjacent to existing power plants. Among the ideas are creation of concrete, plastics, food, and synthetic fuels from the CO2 that would normally be sent into the atmosphere. By 2020, a winner of the competition will be announced.
|Carbon Engineering's pilot plant will remove CO2 from the atmosphere and convert it into liquid fuel. (Image source: Carbon Engineering)|
The first commercial plant to capture CO2 from the atmosphere opened in Zurich, Switzerland in 2017. The Climeworks plant is designed to produce 900 tonnes of CO2 annually, which is supplied to a nearby greenhouse to help grow vegetables. During the Climeworks process, CO2 from the atmosphere is deposited on a special filter. Once the filter is saturated, it is heated and releases the gaseous CO2. The project was one of the eleven finalists of the $25 million Virgin Earth Challenge for CO2 capture technologies that took place in the early 2000s.
Another effort is underway by a Canadian company called Carbon Engineering. It has developed a patented continuous process that uses a solution of potassium hydroxide to capture the CO2 from the atmosphere, converting it into a carbonate. Carbon Engineering was also a finalist in the Virgin Earth Challenge.
Small pellets of calcium carbonate are precipitated from the solution and dried into pellets. These pellets can then be heated to release a pure stream of CO2, which Carbon Engineering plans to use to mix with hydrogen obtained from electrolysis of water to form synthetic gasoline. The company claims that the cost at large scale will be $100 to $150 USD per tonne of CO2 that is captured. This compares favorably with the $600 per tonne that other processes are estimated to cost.