Integrated CO2 Capture and Mineralization Based on Monoethanolamine and Lime Kiln Dust
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Development and deployment of innovative and cost-effective CO 2 capture and utilization technologies can not only reduce the amount of CO 2 currently in or being emitted into the atmosphere but also develop a circular economy and deliver economic growth. Differing from previous studies on amine-based CO 2 capture in isolation, the work herein is focused on an integrated CO 2 capture and mineralization approach with monoethanolamine (MEA) as CO 2 liquid absorbent and utilization of lime kiln dust (LKD) as the CO 2 mineralization feedstock to regenerate or recover MEA used for CO 2 capture. Aqueous solutions containing 2.0 M MEA were used to capture CO 2 from a simulated flue gas comprising a CO 2 concentration of 10.0% (by volume) prior to the addition of LKD powders to precipitate captured CO 2 in the MEA solution through carbonation reactions. Following CO 2 mineralization, MEA filtrate was collected and analyzed by FTIR and ICP-OES, with solid materials undergoing chemical analysis by TGA and SEM, and additionally for particle size. The CO 2 mineralization process was found to be significantly influenced by the solution pH and temperature of the MEA absorbent solution, where conditions below pH 10.5 restrained CO 2 mineralization due to the limited availability of carbonate ions. Conversely, under higher pH conditions, the conversion of carbamate and bicarbonate to carbonate is promoted, accelerating the CO 2 mineralization process. Increasing the absorbent temperature (i.e., from 40.0 to 60.0 °C) resulted in a corresponding and considerable increase in the CO 2 mineralization rate and the CO 2 desorption efficiency of MEA. Following mineralization, the CO 2 desorption efficiency of CO 2 -loaded MEA reaches 79–83%. The CO 2 sequestration capacity of LKD was determined to be ∼230 g CO 2 per kg, with calcite and aragonite forms as the major calcium carbonate products formed during the CO 2 mineralization processes.
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4401992940