A numerical model of transient thermal transport phenomena in a high-temperature solid-gas reacting system for CO2 capture applications

Abstract

A numerical model coupling transient radiative, convective, and conductive heat transfer and mass transfer to chemical kinetics of a heterogeneous solid−gas reacting system has been developed and applied to a model reaction: the decomposition of calcium carbonate into calcium oxide and carbon dioxide. The model reaction is one of two reactions involved in calcium oxide looping, a proposed thermochemical process suitable for use with concentrated solar power for the capture of carbon dioxide. The analyzed system is a porous particle in a reactor-like environment that is subjected to concentrated solar irradiation. The finite volume and explicit Euler methods are used to solve the governing equations numerically. The model predicts the time-dependent temperature distributions as well as local solid and fluid phase composition. It is used to investigate operating conditions under which calcium oxide looping may be employed for carbon capture. The sensitivity of the model is also investigated.