CFD simulation of CO₂ absorption by water-based TiO₂ nanoparticles in a high pressure stirred vessel

This work presents the modeling and simulation of CO₂ capture by a water-based Titanium dioxide (TiO₂) solid nanoparticle in a stirred high-pressure vessel at a constant temperature. Photocatalytic material such as TiO₂ has excellent properties, namely it is nontoxic, inexpensive, and non-polluting. CFD model equations are developed and solved using COMSOL software package. The effect of the concentration of a solid nanoparticle in a water-based TiO₂ solution, the size of TiO₂ nanoparticles and the rate of mixing on the CO₂ absorption rate is investigated. A 2D mathematical model considers both shuttle and micro-convention mechanisms. Results reveal that the best TiO₂ concentration range is between 0.5 and 1 kg/m³ and that a particle size of 10 nm is more efficient than higher particle sizes. A moderate mixing rate maximizes the CO₂ removal rate. The theoretical predictions are validated using lab experimental data and those in the available literature. Results confirm that the model calculations match with the experimental results. Accordingly, the model successfully predicts the experimental data and can be used for further studies.