CO₂ adsorption on pristine, oxidized, and diethylamine-functionalized activated carbon sorbents

¹ Taras Shevchenko National University of Kyiv, Chemical Faculty, 01601 Kyiv, Ukraine
² Prešov University in Prešov, Faculty of Humanities and Natural Sciences, 08001 Prešov, Slovakia

^* Corresponding author: ruslan.mariychuk@unipo.sk

Abstract

Adsorption is currently the most promising capture technology to shorten atmospheric emissions of carbon dioxide (CO₂). In this article, we report on the adsorption of CO₂ onto pristine, oxidized, and aminated activated carbon (AC) sorbents. From our findings, some functionalized AC sorbents have shown very promising results in the CO₂ capture process. Their maximum adsorption capacity measured by the thermogravimetric method at 20 °C varies between 2.2 and 3.9 mmol CO₂/g depending on the content of diethylamino and oxygen-containing groups. The functionalization of the carbon surface with diethylamino groups improves the adsorption capacity by 30–40%. The CO₂ adsorption little depends on the texture parameters of the pristine AC sorbents. In the range from 20 to 100 °C, the CO₂ thermodesorption showed the effective regeneration of the sorbents. The aminated carbon surface demonstrates the best CO₂ adsorption but binds the adsorbed molecules stronger than the oxidized surface, which limits the sorbent regeneration.