Binary carbon dioxide and nitrogen adsorption on pomelo peel-derived porous sorbent.

Ghafar, Nawal Abd; Jamian, Nor Ruwaida; Tan, Lian See; Jusoh, Nurfatehah Wahyuny Che

The rising concern regarding CO 2 emission from fossil fueled-power plants, along with the heightened interest in repurposing biowaste has necessitated the utilization of biowaste as an adsorbent for CO 2 capture. In this study, the pomelo peel-derived activated carbon (POM-AC) was investigated as a potential adsorbent for post-combustion CO 2 capture application, which involves capturing CO 2 from the CO 2 and N 2 gas mixture. The POM-AC was characterized, revealing a microporous-mesoporous structure that contains various surface functional groups including hydroxyl, carbonyl, carboxyl, and alkene groups. The strong affinity of POM-AC towards CO 2 over N 2 was demonstrated from the increment in the CO 2 and N 2 gas mixture uptake with the increase in CO 2 gas compositions. The total adsorption capacity of POM-AC at ambient conditions for 100% CO 2 , 15% CO 2 , 10% CO 2 , and 5% CO 2 is 127.8 mg/g, 55.7 mg/g, 49.1 mg/g, and 38.3 mg/g, respectively. Notably, POM-AC outperformed the commercial activated carbon (Chemiz-AC) at simulated post-combustion conditions due to POM-AC having smaller pores than Chemiz-AC. The Ideal Adsorbed Solution Theory (IAST) prediction of binary CO 2 and N 2 adsorption equilibria showed higher CO 2 adsorption capacity than N 2 at post-combustion gas compositions (5–15% CO 2), which further suggests its stronger preferential of CO 2 over N 2. Furthermore, a relatively high CO 2 /N 2 selectivity of 23.9 was predicted for 15% CO 2 gas composition. The adsorption isotherm and kinetic analysis revealed that the surface of POM-AC is heterogenous, and the rate-controlling step of CO 2 and N 2 adsorption is physisorption. Coupled with the utilization of a zero-cost biowaste as an activated carbon precursor, these findings showed that POM-AC could be a promising adsorbent for post-combustion CO 2 capture application. [Display omitted] • Pomelo peel-derived activated carbon for CO 2 and N 2 adsorption. • Better CO 2 -N 2 uptake than Chemiz-AC due to smaller pores. • IAST predictions shows strong preference of CO 2. • High selectivity of 23.9 at 15% CO 2.

CARBON sequestration; GRAPEFRUIT; GAS mixtures; CARBON emissions; CARBON dioxide; CARBON dioxide adsorption

Chemical Engineering Research & Design: Transactions of the Institution of Chemical Engineers Part A, 2023, Vol 199, p21

0263-8762

Academic Journal

10.1016/j.cherd.2023.09.018