Preliminary study for the suitability of eucalyptus chips and coal for combustion in a fluidized bed reactor

Abstract

The combustion with fluidized bed reactors has as main advantages the best energy utilization of combustible materials and a lower generation of pollutants. The fluidization success depends on the characteristics of the particles that compose the bed. This research aimed to perform a preliminary evaluation and characterization of the energy potential and the fluidization curves in fluidized beds formed by binary mixtures of eucalyptus chips + sand and mineral coal + sand. We tested: 1) physical characterization of solid fuels; 2) chemical characterization of combustible materials; 3) thermogravimetric analysis of fuels; 4) determination of the fluidization curves and minimum fluidization velocity for a polydisperse bed. We observed 19.15 MJ kg-1 of lower calorific value for eucalyptus chips and 10.1 MJ kg-1 for coal. The increase in biomass percentage in mixture caused a pressure drop in bed, indicating the formation of preferred paths and a necessity to increase fluid velocity. The fluidization of coal and Eucalyptus chips can be viable in a bubbling fluid bed process, motivating future theoretical and experimental studies involving the application of this methodology in the development of clean and sustainable technologies.