Application of Eddy Dissipation Concept for Modeling Biomass Combustion, Part 2: Gas-Phase Combustion Modeling of a Small-Scale Fixed Bed Furnace

Small-scale grate-firing biomass furnaces suffer from high levels of pollutant emissions caused mainly by a low level of air/fuel mixing and a short residence time for combustion as a result of their small volume. Reliable gas-phase combustion modeling is key for improving the design of these systems. The present work describes a computational fluid dynamics study of biomass combustion using the modified eddy dissipation concept (EDC) model. Part 1 ( 10.1021/acs.energyfuels.6b01947 ) of this study focused on examining the main challenges of the EDC model regarding its application for modeling weakly turbulent and slow-chemistry reacting flows. In addition, a sensitivity analysis was carried out on the constants of the model for modeling non-premixed combustion at weakly and highly turbulent reacting flow conditions. Using the conclusions of the analysis of part 1 ( 10.1021/acs.energyfuels.6b01947 ), gas-phase combustion of a small lab-scale grate-firing biomass furnace is simulated in the present paper (part 2). The results revealed that the modified EDC model produced reasonable predictions of the temperature and gas emissions.