Chemists working at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have demonstrated a new, energy-efficient method of pulling carbon dioxide (CO2) directly from the air. It could potentially be used to help fight back against the effects of climate change, which is partly the result of increased atmospheric CO2 concentration due to human activity. What magical, cutting-edge technology did the researchers use for their tech demo? An off-the-shelf air humidifier and a solar-powered hot dog cooker.
“First, we employed environmentally friendly amino acid sorbents, together with a household air humidifier to quickly absorb CO2 out of the air and convert it into carbonate ions,” Radu Custelcean, the ORNL chemist who conceived of the technique, told Digital Trends. “Second, we reacted the loaded sorbent with a simple guanidine compound (read: guanidines are naturally found in proteins and strongly bind negatively charged ions like carbonate), which stripped the carbonate ions from the sorbent solution and converted them into highly insoluble crystals. Finally, the carbonate crystals were gently heated with the solar oven to release the CO2, so it can be sent out for long-term geologic storage, and regenerate the guanidine.”
Currently, this technique has only been demonstrated in the lab, but it poses immense possibilities in the event that it can be scaled up and optimized. It could help address the problem of climate change by reducing the atmospheric CO2 concentration spat out by humans — and do so in a more efficient way than other methods.
“Scaling up should be feasible,” Custelcean continued. “Of course, we would not use a hot dog cooker at a million ton of CO2 scale, but the same principle could be translated at a much larger scale using standard parabolic-trough solar concentrators. At the same time, for the CO2 absorption step, one could use larger air-liquid contactors, such as those used in cooling towers.”
The next step for the project is for the researchers to find an industrial partner to work with. As Custelcean noted, to make an impact on climate change, the scale of CO2 removal would have to be in the order of 100 million tons a year. This would mean multiple such plants removing billions of tons of CO2 from the atmosphere every year in order to have a hope of stabilizing the climate.
A paper describing the research was recently published in the journal Nature Energy.