Capturing CO2 is one of the many tasks trees have been doing for ages. Now, though, with all the CO2 being emitted into the atmosphere and the trees being cut off, the existing forests are not able to keep up with the ongoing pollution.
Many solutions have been looked for, and some have come up with ingenious ones. For example, researchers from Universidad Nacional Auti³noma de México have found that the lithium aluminate Li5AlO4 absorbs CO2 over a wide temperature range, and may be an alternative to capturing agents based on heavier elements.
A paper on their work was published in the ACS Journal of Physical Chemistry A.
Li5AlO4 absorbed CO2 in a wide temperature range from 200 to 700 °C, but it sintered as a function of temperature. At low temperatures, the CO2 absorption decreased because of the sintering effect, which implies a reduction of the surface area. However at high temperatures, this phenomenon was not observed because lithium diffusion was activated.
Last but not least, it has to be mentioned that aluminum is a lighter element in comparison with the other elements used as structural ceramics for this application, for example silicates (Li4SiO4 and Li2SiO3), cuprates (Li2CuO2), zirconates (Li2ZrO3 and Li6Zr2O7), or titanates (Li4TiO4). Therefore, because Li5AlO4 has the best theoretical CO2 chemisorption capacity per gram of ceramic among the lithium ceramics and because of the results obtained, Li5AlO4 may become an important case of study as a CO2 captor.
Capturing carbon dioxide and saying the problem is solved is like cutting the very branch we sit on. Producing less CO2 is desirable, but unattainable properly by current means of producing energy (like coal plants). We have to reduce our energy consumption – it’s like lowering our cholesterol by sporting more and eating less (that’s something I really have to do).