Fluidized-Bed Combustion of Selected Wood Chars from the Semi-arid Northeastern Region of Brazil

Abstract

We herein present some results obtained from the burning of chars derived from wood originated in the semi-arid region of northeastern Brazil (Cariri Paraibano) in a fluidized-bed reactor. A series of tests was performed in air and 10:90% (v/ v) mixtures of oxygen and nitrogen. The average diameter of the burning particles ranged from 1.8 to 3.6 mm for bed temperatures of both 750 and 850 °C. The temperature of the burning particles was determined using an energy balance at the surface of the particle. The maximum difference in the temperature between the particles and the bed was 82 °C, when the particles were burned in air. This difference decreased to 41 °C when the particles were burnt in a 10:90% (v/v) mixture of oxygen and nitrogen. Both kinetic and diffusive data were collected, in response to the general lack of this type of data in the literature relating to the design of fluidized-bed combustors.