CFD Simulation of the Regenerator Section of a Carbon Capture Unit Using Amine Based Solid Sorbent

Carbon capture using amine-based solid sorbents from existing flue gas of fossil-fuel-fired power plants has been considered as a promising approach in comparison with the conventional liquid-based systems. National Energy Technology Laboratory (NETL) designed an integrated adsorption and regeneration system of fluidized beds to investigate the capacity of amine-based sorbents. In this study, the focus has been on the computational fluid dynamics (CFD) simulation of the NETL regenerator fluidized bed reactor. After exiting the carbonator, CO_2-laden solid sorbents enter the regenerator at a higher temperature, which causes CO₂release from carbonated amine sorbents.

In this study, the Eulerian-Eulerian two-fluid model is used to conduct two-dimensional CFD simulationof the regeneration section of the NETL circulating fluidized bed system. Kinetic theory was used as the constitutive relation to analyze the particulate phase flow model along with frictional stress and viscosity for the dense solid flow regimes. In addition to continuity and momentum conservation equations, species conservation and energy conservation equations were also solved to calculate the CO₂desorption rate, regeneration efficiency of the sorbents, and flow temperature distribution in the system.