DOI: https://doi.org/10.55373/mjchem.v26i3.251

Keywords: CO2 adsorption; chemical activation; acid-treatment; adsorbent

Abstract

The increasing CO2 output has garnered significant attention, with CO2 adsorption being a highly efficient method for capturing and utilizing this greenhouse gas. In this study, clay soil, which is naturally abundant, was examined for its potential application as a CO2 capture adsorbent. Clay soil samples were activated with phosphoric acid (H3PO4-S) to increase their textural properties, especially their surface area and pore volume. The work includes insights on acid activation processes in soil as carbon dioxide adsorbents and their prospective uses in solid sorbent systems. Soil-based adsorbents were characterized by X-ray powder diffraction (XRD), Brunauer, Emmett, and Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. The BET surface area of the soil increased to 60.32 m2/g after being activated with H3PO4, which is twice as high as the untreated soil (23.39 m2/g). The micropore volume value; H3PO4-S (0.14 cm3/g) micropore volume value is double that of untreated soil (0.07 cm3/g). These enhanced textural properties allow for a greater capacity to trap and store CO2 molecules. In comparison to untreated soil, the H3PO4-S adsorbent obtained an adsorption capacity of 10.60 mg/g, which the performance of the acid-treated soil improved by 16%. Referring to the experimental findings, the activated soil as an adsorbent showed increment in CO2 adsorption capacity, further supporting its potential as an effective carbon capture adsorbent.