Improvement in cyclic CO2 capture performance and fluidization behavior of eggshell-derived CaCO3 particles modified with acetic acid used in calcium looping process. (November 2022)

• Record Type: Journal Article
• Authors: Imani, Mehri; Tahmasebpoor, Maryam; Sánchez-Jiménez, Pedro Enrique; Valverde, Jose Manuel; Moreno, Virginia
• Is Part Of: Journal of CO₂ utilization. Volume 65(2022)
• Publication Date: 2022-11
• Subjects: Acetic acid -- Calcium looping -- CO2 capture -- Eggshell-derived CaCO3 -- Fluidization; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2022.102207
• Languages: English
• ISSNs: 2212-9820

Abstract

Abstract: Although calcium-based materials are the most promising adsorbents used in calcium looping process for carbon dioxide removing, their CO2 capture capacity decaying besides poor fluidization, still are the important challenges. In the present investigation, eggshell as a cheap, easily available and unpolluted source of calcium carbonate was used for CO2 capturing in calcium looping process. Eggshell particles were treated with various volume concentrations of acetic acid to improve its sorption capacity. According to the TGA results after 20 carbonation/calcination cycles, the effective carbonation conversion of modified eggshell with 5%, 20%, 30% and 40%. v/v acetic acid was 21.33%, 24.26%, 25.97% and 28.97%, respectively, which is considerable compared to 20.54% for untreated eggshell. The effect of initial eggshell particle size on the adsorption behavior of final adsorbent was also investigated by using two different sizes including dp< 45 µm and dp> 320 µm. The results showed that the effective conversion of the adsorbent containing 40%. v/v acetic acid derived from small particle size eggshells was 9.32% higher than that from larger particle size eggshells. In terms of fluidization behavior, surprisingly the addition of acetic acid to the eggshell particles also increased the bed expansion ratio as 8% and 36.2% at gas velocities of 0.27 and 6.67 cm/s, respectively. Further improvement in the fluidity of eggshell modified with 40% acid was performed by manually mixing of SiO2 nanoparticles at different weight percentages. According to the results, adding 7.5 wt% SiO2 leaded to the homogeneous and agglomerate particulate fluidization. Graphical Abstract: ga1 Highlights: Eggshell-derived CaCO3 were modified by acetic acid in various concentrations. Prepared adsorbents were subjected to calcination/carbonation cycles in TGA. Effect of initial eggshell particle size on CO2 capture capacity was investigated. Adding 40% acetic acid to the eggshell increased both capture capacity and fluidity. 7.5% SiO2 leaded to uniform APF behavior and even 3.02% increased CaO conversion.