Keywords

coal, char oxidation, oxy-fuel, kinetics, sensitivity analysis

Abstract

Oxy-fired coal combustion is a promising potential carbon capture technology. Predictive CFD simulations are valuable tools in evaluating and deploying oxy-fuel and other carbon capture technologies either as retrofit technologies or for new construction. However, accurate predictive simulations require physically realistic submodels with low computational requirements. In particular, comprehensive char oxidation and gasification models have been developed that describe multiple reaction and diffusion processes. This work extends a comprehensive char conversion code (CCK), which treats surface oxidation and gasification reactions as well as processes such as film diffusion, pore diffusion, ash encapsulation, and annealing. In this work several submodels in the CCK code were updated with more realistic physics or otherwise extended to function in oxy-coal conditions. Improved submodels include the annealing model, the swelling model, the mode of burning parameter, and the kinetic model, as well as the addition of the chemical percolation devolatilization (CPD) model. Results of the char combustion model are compared to oxy-coal data, and further compared to parallel data sets near conventional conditions. A potential method to apply the detailed code in CFD work is given.

Original Publication Citation

Holland, T. and T. H. Fletcher, “A Comprehensive Model of Single Particle Pulverized Coal Combustion Extended to Oxy-coal Conditions,” Energy and Fuels, 31, 2722−2739 (2017). DOI: 10.1021/acs.energyfuels.6b03387