Computational and experimental investigation of CO2 capture in gas–solid bubbling fluidized bed

Abstract

There are growing concerns about increasing emissions of greenhouse gases and looming global warming crisis. Recently, CO2 chemical adsorption using recoverable solid adsorbents has been studied as an energy-efficient method for the capture of carbon dioxide from the flue gases. In this study, CO2 sorption from the flue gases has experimentally and computationally been investigated using potassium carbonate particles in a bubbling gas–solid fluidized bed. A laboratory scale fluidized bed has been employed to better understanding hydrodynamics and adsorption kinetics of the process. An Eulerian–Eulerian two-fluid approach based upon the kinetic theory of granular flow with a modified interphase exchange coefficient was applied to describe the gas–solid flow in a bubbling fluidized bed. Comparisons of the model predictions of the bed expansion ratio, bubbles behavior and CO2 concentration along the fluidized bed height with the experimental results indicated reasonable agreement between them. A comparison between CO2 concentrations at the reactor outlet from CFD simulation using the applied two kinetic models and experimental results demonstrates that the kinetic model containing H2O concentration in reaction rate provides much better results.