ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Investigation on medium-temperature carbon dioxide capture performance over zeolite supported CaO adsorbents: synthesis and performance evaluation

Xing Gang Zhang, Archina Buthiyappan, Abdul Aziz Abdul Raman, Hendrik Simon Cornelis Metselaar, Jegalakshimi Jewaratnam, and Yee Seng Tan

Sustainable Process Engineering Centre (SPEC), Department of Chemical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur, Malaysia

E-mail: archina@um.edu.my

Received: 7 November 2024  Accepted: 13 January 2025

Abstract:

This study aimed to develop various CaO/zeolite adsorbents tailored for mid-temperature CO₂ adsorption. It investigated the CO₂ uptake efficiency of these adsorbents during carbonation–decarbonation cycles, highlighting the effect of CaO loading on the adsorption efficiency of adsorbents produced by different synthesis methods. CO₂ temperature-programmed desorption (CO₂-TPD) confirmed the CO₂ uptake capacity of CaO/USY at medium temperatures (300 °C). Among the CaO/zeolite adsorbents synthesized, the 10% CaO/USY exhibited the highest adsorption capacity at 300 °C, with a CO₂ uptake of 34.94 mmol·kg⁻¹ during the first cycle. The adsorbent also maintained its CO₂ capacity at 21 mmol·kg⁻¹ over the next nine cycles. Physicochemical analysis revealed that the porous volume of the 10% CaO/USY adsorbent was 0.28 cm³·g⁻¹, and its substantial surface area was 506.20 m²·g⁻¹, as determined through N₂ adsorption measurements. Characterization using FTIR and FESEM confirmed the successful loading and uniform dispersion of CaO on USY, respectively. X-ray diffraction (XRD) analysis revealed that 10% CaO/USY exhibited a smaller CaO crystallite size (29 nm) compared to bulk CaO (65 nm) and 15% CaO/USY (32 nm). Additionally, XRD identified the presence of calcium silicate salts (CaSiO₃ and Ca₂SiO₄) and calcium aluminate salts (Ca₁₂Al₁₄O₃₃), which reduce the CO₂ capture capacity but enhance cyclic stability. This finding suggests a potential approach to enhancing the effectiveness of adsorbents by optimizing the conversion of CaO into these salts. The results provide valuable insights for advancing and scaling up CaO/zeolite adsorbents for CO₂ capture.

Graphical abstract

Keywords: Calcium Oxide (CaO); CO2 Capture; Adsorbent; Zeolite; Medium Temperature

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-03899-8

Chemical Papers 79 (3) 1927–1943 (2025)