New Material for CO2 Absorption

Researchers at Universidad Nacional Autónoma 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.

—Ávalos-Rendón et al.

Resources

• Tatiana Ávalos-Rendón, Julio Casa-Madrid and Heriberto Pfeiffer (2009) Thermochemical Capture of Carbon Dioxide on Lithium Aluminates (LiAlO₂ and Li₅AlO₄): A New Option for the CO₂ Absorption. J. Phys. Chem. A, 113 (25), pp 6919–6923 doi: 10.1021/jp902501v