Experimental and numerical study of calcium carbonate precipitation for CO2 trapping in an industrial unit using a semi-batch reactor: Parameter estimation and multi-objective optimization--颗粒学报PARTICUOLOGY

Experimental and numerical study of calcium carbonate precipitation for CO₂ trapping in an industrial unit using a semi-batch reactor: Parameter estimation and multi-objective optimization

Luiz Filipe Lima Martins^a, Fran Sérgio Lobato^a *, Sandra Cristina Dantas^b, Carla Eponina Hori^a

a School of Chemical Engineering, Federal University of Uberlândia, Uberlândia, Brazil
b Department of Chemical Engineering, Federal University of Triângulo Mineiro, Uberaba, Brazil

10.1016/j.partic.2026.02.028

Volume 112, May 2026, Pages 170-182

Received 13 November 2025, Revised 20 February 2026, Accepted 23 February 2026, Available online 14 March 2026, Version of Record 21 March 2026.

E-mail: fslobato@ufu.br

Highlights

• CO₂ absorption and CaCO₃ precipitation modeled in a semi-batch reactor.

• Phenomenological and kinetic parameters estimated via inverse problem.

• Process variables analyzed using central composite design and meta-models.

• CO₂ mass transfer coefficients consistent with literature values.

• Multi-objective optimization identified optimal operating conditions.

Abstract

The search for sustainable carbon dioxide (CO₂) capture and reutilization strategies has intensified due to the environmental impact of industrial emissions. In this study, the calcium carbonate precipitation process via CO₂ absorption into an aqueous solution of calcium hydroxide in a stirred semi-batch reactor is investigated. The mathematical model describing this process incorporates both absorption and reaction kinetics, as well as hydrodynamic conditions. Phenomenological and kinetic parameters are estimated by formulating and solving an inverse problem based on experimental data from the industrial unit, considering different initial calcium ion concentrations. Furthermore, the influence of operational variables (solid content, CO₂ concentration, and mixing speed) on time to completion and the mass of carbonates formed was assessed using a central composite design. A multi-objective optimization problem was formulated to determine the operational conditions that minimize time to completion and maximize the mass of carbonates formed. The results demonstrate that the proposed methodology provides accurate estimates for the CO₂ mass transfer coefficient, which are in good agreement with literature values. However, for the kinetic parameters, the obtained ranges were not consistent with those reported in the literature. This discrepancy is likely due to the fact that the sample used was not pure. From a statistical perspective, the obtained meta-models were not influenced by the mixing speed. The points forming the Pareto curve correspond to higher values of CO₂ concentration and solid content within the defined domain. Finally, a trade-off solution between the objectives was determined, allowing for the selection of a point on the Pareto curve for practical application.

Graphical abstract

Keywords

Calcium carbonate precipitation; CO2 Trapping; Phenomenological model; Inverse problem; Differential evolution; Multi-objective optimization

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