Mathematical modeling of a moving bed reactor for post-combustion CO2 capture

A mathematical model for a moving bed reactor with embedded heat exchanger has been developed for application to solid sorbent-based capture of carbon dioxide from flue gas emitted by coal-fired power plants. The reactor model is one-dimensional, non-isothermal, and pressure-driven. The two-phase (gas and solids) model includes rigorous kinetics and heat and mass transfer between the two phases. Flow characteristics of the gas and solids in the moving bed are obtained by analogy with correlations for fixed and fluidized bed systems. From the steady-state perspective, this work presents the impact of key design variables that can be used for optimization. From the dynamic perspective, the article shows transient profiles of key outputs that should be taken into account while designing an effective control system. In addition, the article also presents performance of a model predictive controller for the moving bed regenerator under process constraints. (c) 2016 American Institute of Chemical Engineers AIChE J, 62: 3899-3914, 2016