CONSIDERATIONS ON EXPERIMENTAL STUDIES OF VEGETABLE CHAR COMBUSTION IN FLUIDIZED BED

This paper reports some experimental aspects of the combustion of batches of vegetable chars in a fluidized-bed laboratory reactor at temperatures of 600, 700, and 750oC. Data on the volumic concentrations of carbon oxides and volatile organic compounds along the combustion process are presented and discussed. Tests show that the carbon conversion rate is not only due to combustion, but there are pyrolysis phenomena that accompany it and contribute to the global conversion rate of the carbon. The burned-out and consumed mass fractions of carbon were determined, and it was observed that these two quantities differ, particularly for lower bed temperatures. Vegetable chars when suffering combustion in low-temperature fluidized beds release tars in the form of vapors that escape from the bed without burning.