Carbon dioxide (CO₂), though naturally occurring, is considered detrimental at the levels humans are releasing into the atmosphere by burning fossil fuels. Greenhouse gases, like CO_2, trap heat in the atmosphere and keep the planet from getting too cold but the amount we are producing could be making it too hot and global warming is not just another way of forecasting “awesome beach weather.”  The carbon cycle can remove some CO₂  but not as quickly as we need it to because of our high emission rate. Current methods of removal are energy intensive and inefficient and scientists are reporting that they have discovered an improved way to remove CO₂  from smokestacks and the open air.  

Chemistry Nobel Laureate George A. Olah,  Alain Goeppert, and G. K. Surya Prakash worked with colleagues to test “solid materials based on polyethylenimine, a readily available and inexpensive polymeric material” to reduce CO₂ emissions. They even tested the material in humid conditions that would normally make “scrubbing” CO₂ from the air difficult. 

The group used a “silica-organic hybrid”, FS-PEI which is “based on fumed silica impregnated with polyethylenimine,” as the solid adsorbent for their studies. The use of the word “adsorbent” is not a typo in this instance.The difference between the word “adsorbent” and “absorbent” is not just the “d.”

Absorbing is a process we see often, a material sucking up a liquid or gas, like a paper towel absorbs water. Adsorbing is different because the material does not take in the liquid or dissolved solid but instead let’s it accumulate on the surface. Now that we have, hopefully, properly explained the difference between the two processes let’s get back to FS-PEI. 

“The researchers suggest the materials may be useful on submarines, in smokestacks or out in the open atmosphere, where they could clean up carbon dioxide pollution that comes from small point sources like cars or home heaters, representing about half of the total CO₂ emissions related to human activity.”

Does this mean the material could eventually be sold for use in the home? Perhaps in a way similar to desiccant packages which are used to prevent moisture damage to electronics and shoes?  The scientists spoke of the material’s ability to be re-used, “After capturing carbon dioxide, the materials give it up easily so that the CO₂ can be used in making other substances, or permanently isolated from the environment. The capture material then can be recycled and reused many times over without losing efficiency.” 

Will we one day see recycling centers that will take this material to extract the CO₂  and then return the material back to use again? Or maybe there will be a company that is in charge of sending a worker to professionally extract the CO₂ and then take it to a factory that uses the material at a faster rate than a residence? The scientists believe their findings are promising and more research is needed. If the material is indeed as effective as they’ve found there may be a push to make it easy for home use. There may be a far-off day when we go to the store and our list will read: “bananas, bread, milk, CO₂  scrubber.”