Paulo Cardozo  Carvalho de Araújo, Degival Rodrigues  Gonçalves Júnior,, Antônio  Santos Silva, Rodolpho  Rodrigues Fonseca, Lucio  Cardozo-Filho, José  Jailton Marques, Diógenes  R.L. Vedoy, Edilson  de Jesus, 
    Assessment of CO<sub>2</sub> Adsorption Capacity under Moderate Pressure Range on
Activated Carbon Produced from Coconut Endocarp,
    Journal of Engineering and Applied Sciences,
    Volume 15,Issue 2,
    2020,
    Pages 468-478,
    ISSN 1816-949x,
    jeasci.2020.468.478,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2020.468.478)
    Abstract: In this study, we prepared activated carbon using coconut residue (<em>Cocos nucifera</em> L.) and evaluate
the potential use of this activated carbon for capture and storage of carbon dioxide (CO<sub>2</sub>). Regeneration tests
indicated that the activated carbon has a good regenerative capacity and maypotentially be used in CO<sub>2</sub>
adsorption systems. For example, the ability of the activated carbon to capture and then release CO<sub>2</sub> is not
significantly affected even after three consecutive adsorption/desorption cycles, regardless of the temperature
tested (either 125, 150 or 180&deg;C). Kinetic studies revealed that the time required for total saturation of the
activated carbon was 25 min for the pressure range investigated (0.14-0.34 MPa). This ability to retain
considerable amounts of CO<sub>2</sub> quickly under low pressures is likely due to the presence of microporous at the
surface of this adsorbent, as suggested by reports in the literature and the morphological features of the
activated carbon presented here. In addition, equilibrium studies using the Langmuir and Freundlich isotherms
showed that the activated carbon has a maximum adsorption capacity of 76.03 mg g<sup>&#150;1</sup> at 15&deg;C. This adsorption
capacity decreases with temperature increase, reaching 58.84 mg g<sup>&#150;1</sup> at 35&deg;C. Similar behavior has been
observed for other absorbents and is expected for adsorption processes due to the exothermic nature of these
processes. In summary, the results indicated that the activated carbon produced with coconut residue has great
potential as a CO<sub>2</sub> absorbent.
    Keywords: Coconut endocarp;CO2 removal;adsorption;equilibrium;kinetics;temperature