(398c) Validation of CFD Model for the Pilot Scale Mineral Carbonation Bubble Column Reactor

As the global warming issue attracts worldwide attention, CCU(Carbon Capture and Utilization) technology is being actively studied. Mineral carbonation process, one of the CCU technology, removes carbon dioxide in flue gas by reacting with calcium hydroxide, and use the product, calcium carbonate, as a raw material for cement. In order to study on mineral carbonation reactor, a pilot scale mineral carbonation bubble column reactor of 2.2 m in diameter and 6.0 m in height was built in Incheon, South Korea.

Diameter of the mineral carbonation bubble column reactor should be at least about 10 m to remove more than 100,000 tons of carbon dioxide in a year. However, most of the studies on bubble column reactor have been intensively studied on laboratory scale with a diameter of less than 30 cm. Few studies on large bubble column reactor only compared the experimental results with empirical equation. Even in the studies using CFD(Computational Fluid Dynamics), which can simulate bubble coalescence and breakage for calculating gas holdup and interfacial area by using PBM(Population Balance Model), the studies are limited on laboratory scale due to the enormous computational cost.

In this research, the pilot scale mineral carbonation bubble column reactor was modeled using the CFD with Eulerian-Eulerian approach. This approach has dramatically cheap computational cost versus Eulerian-Lagrangian approach coupling CFD and PBM. The CFD results for gas holdup, interfacial area and mass transfer coefficient were compared with empirical equation to obtain a reliability of the CFD model. Finally, by comparing the CFD results for the CO₂removal efficiency with actual experimental results, the CFD model was validated.

The CFD results for the three parameter and the CO₂ removal efficiency showed an error of 5, 7 %, respectively. Furthermore, correction diameter was introduced to calibrate the diameter in a large bubble column reactor. After this correction diameter was applied, an error of the CFD results for the CO₂removal efficiency was reduced to about 2 %.

This study suggests the possibility of modeling a pilot scale bubble column reactor using the CFD with computational efficiency. Based on the CFD model, four times larger bubble column reactor will be built in 2017.