Inline Mixing and Separation in a Tubular Reactor for Carbon Mineralization

In this work, the fluid dynamics characteristics of a gas-liquid tubular reactor designed for accomplishing the ex-situ continuous conversion of gaseous CO2 to solid carbonates is investigated. The study is based on a combination of experiments and simulations concerning a pipe equipped with Kenics type static elements, which can be adopted for ensuring turbulent mixing and gas-liquid mass transfer or gas-liquid separation, depending on the relative orientation of the single elements. The experimental activity is aimed at collecting data on the bubbles size and the gas volume fraction distributions in different co-current gas-liquid flow conditions by optical and tomographic techniques. The computational part of the work is based on the application of the Reynolds Averaged Two Fluid Model for the prediction of the gas-liquid flow characteristics, which affect the tubular reactor performances and the energy requirement. A preliminary analysis on the numerical errors, due to the spatial discretization of the computational domain close to the Kenics elements, is presented. The model evaluation based on the comparison of the simulation results with the experimental data highlights the current capability and limitations of Computational Fluid Dynamics based methodology for design, optimization and scale-up of the equipment.