Fluidized bed technology is an established technology for energy generation due to low operating temperatures, high system efficiency, fuel flexibility, and easier control of pollutants such as NOx and SO. Co-firing of biomass is an attractive option for power generation as it increases use of renewable and waste materials, thereby replacing the conventional coal. This paper investigated biomass co-firing in a fluidized bed using two models. The first model is based on the recent study on the high-volatile solid fuels in a fluidized bed. The first model considered the fluidized bed combustor as three distinct zones: bed zone, splashing zone, and freeboard zone, and took into account material balances in each zone. In addition, sub-models for estimating the pollutants such as NOx and SO were also included in the model. The second model was based on the coal combustion in a fluidized bed. The second model only considered bed and freeboard zones in a fluidized bed. The model for pollutant emissions was also included in the second model. The predictions of both models included char loading in the bed, combustion efficiency, and pollutant emissions. Predictions of both models were compared with the available experimental data to validate the models. The results of the study suggest that current coal models may be appropriate to apply for biomass co-firing in fluidized coal combustors as long as the biomass co-firing is limited to not more than 30% of the total fuel.
Oxy-coal combustion in a 30 kWth pressurized fluidized bed: Effect of combustion pressure on combustion performance, pollutant emissions and desulfurization
