A 1-d zone model for the axial burning profile of liquid fuels in bubbling fluidized beds

This paper extends to liquid fuels a previously developed 1-D model for combustion of high-volatile solid fuels. The model considers fuel combustion in three zones, i.e. bubbling bed, splashing region and freeboard, and takes into account thermal feedback from the splashing region to the bed associated to solids ejection/falling back. Homogeneous phase oxidation kinetics is considered in the model by means of a simple "global reaction scheme". Calculations have been carried out within a bed temperature range of 500-850°C, where both homogeneous kinetics and mixing/diffusion exert a significant influence on combustion. The main model results are the axial profiles of the hydrocarbon fuel burn-off and the temperature increase in the splashing region. Thanks to its simple structure and short calculation times, the model is a handy and reasonable study tool; on the other side, it is enough representative of actual phenomena and mechanisms.