Improvement on CO2 capture by CaO pellet modified with carbon nanotubes

Abstract

In this work, we developed an efficient absorbent material pellet-based made of calcium oxide to capture part of the CO2 emitted by motor vehicles, to obtain an innovative technology for controlling the emission of greenhouse gases. Problems with CO2 capture efficiency using CaO was solved after modifications with carbon nanotubes (CNTs) that improve CaO adsorbent porosity leading high CO2 capture efficiency (98.2%). The CO2 gas adsorption by pellet was followed by thermogravimetric analysis showed that porosity generated promoted a better CO2 adsorption compared to unmodified CaO (64.1%). The results strongly suggest that the preparation of CaO pellet-based in the presence of a small amount of nanotubes (0.05%), followed by calcination, promotes the formation of channels that allow to substantially improve CO2 capture capacity by increasing the exposing adsorbent calcium species. This effect may be due to the crystallite size of the materials. The calcium oxide, after modification with carbon nanotubes, showed particle size values of 25 and 17 nm, respectively, before and after calcination.