New carbon dioxide scrubber

Science : A new kind of plastic that can remove large amounts of CO ₂ from the air has been produced by a research team led by George Olah of the University of Southern California in Los Angeles. Olah and his team needed a CO ₂ absorber for iron-based batteries they were working on; they tried using polyethylenimine (PEI), an inexpensive CO ₂ absorbing polymer. PEI grabs CO ₂ only on its surface, so to increase its surface area, Olah dissolved the polymer in a methanol solvent and spread it atop a batch of fumed silica, an industrially produced porous solid made from microscopic droplets of glass fused together. When the solvent evaporated, it left solid PEI with a high surface area. When the team tested the new material’s ability to absorb CO ₂, they found that in humid air each gram of the material absorbed an average of 1.72 nanomoles of CO ₂. That’s one of the highest levels of CO ₂ absorption from air ever tested. The material also sheds CO ₂ when it’s heated to 85 °C, whereas other solid CO ₂ absorbers have to be heated to over 800 °C to shed CO ₂. The new polymer could be used to scrub CO ₂ from the air, although it couldn’t be used in industrial smokestacks or automobile tailpipes without additional tinkering to make it more heat-resistant.