RESUMEN

Activated carbons were prepared from different Amazonian fruit waste-derived biomass residues from the Amazon to store CO2 at low pressure. The samples were carbonized in under flowing N2 flow atmosphere and activated with KOH. The carbon materials obtained were physically and structurally characterized by the analysis of N2 isotherms for textural characterization, X-ray fluorescence (XRF), ash content, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and applied for CO2 adsorption. Temperature programmed desorption (TPD), the isosteric heat were also calculated. The values of the specific surface area (SBET) ranged from 1824 to 2004 m2/g, and the total pore volume varied between 0.68 and 0.79 cm3/g. These results confirm that the obtained activated carbons are microporous materials. The highest CO2 adsorption under the pressure of 1 bar was achieved in activated carbon derived from andiroba seeds ANKO1, the adsorption of carbon dioxide at 1 bar was being 7.18 and 4.81 mmol/g at 273 K and 298 K, respectively. As a result, the most important factor in the preparation of activated carbon for CO2 capture is primarily rich in extremely the high amount of small micropores.

Asunto(s)

Dióxido de Carbono , Carbón Orgánico , Adsorción , Biomasa , Frutas

RESUMEN

Although traditionally high-surface area carbon materials have been considered as rigid structures with a disordered three dimensional (3D) network of graphite microdomains associated with a limited electrical conductivity (highly depending on the porous structure and surface chemistry), here we show for the first time that this is not the case for activated carbon materials prepared using harsh activation conditions (e.g., KOH activation). In these specific samples a clear structural re-orientation can be observed upon adsorption of different organic molecules, the structural changes giving rise to important changes in the electrical resistivity of the material. Whereas short chain hydrocarbons and their derivatives give rise to an increased resistivity, the contrary occurs for longer-chain hydrocarbons and/or alcohols. The high sensitivity of these high-surface area carbon materials towards these organic molecules opens the gate towards their application for sensing devices.