Author(s)

C. A. Torres-Balcazar, G. Lopez-Ocaña, R. G. Bautista-Margulis, J. R. Hernandez-Barajas, H. O. Rubio-Arias & R. A. Saucedo-Teran

Abstract

Outdoor incineration of low-grade solid fuels is still an inadequate and common practice in developing countries worldwide. To date, advanced combustion systems, such as fluidized bed, have been successfully developed and implemented to deal with these environmental issues. However, optimum operating conditions have to be attained in order to reach the highest combustion efficiency of each particular system. The objective of this investigation was to study the combustion efficiency behaviour of urban solid wastes (USW) in an experimental fluidized bed combustor under various operating conditions. Five experimental tests were conducted by using USW collected in the city of Villahermosa-Tabasco, Mexico. The experimental tests were carried out under the following conditions: excess air of 281%, bed particle size of 0.8 mm and static bed height of 0.2 m. The combustion efficiency varied from 54 to 82% at a bed temperature between 770 and 914ºC, being significantly correlated to a minimum square regression model (R2 = 0.87, p < 0.01). At bed temperatures lower than 800ºC, the USW composition and heterogeneity affected the combustion efficiency (54-64%), giving rise to an increase in CO emissions (1,092 ppm). At bed temperatures greater than 870ºC, however, high combustion efficiencies (80-82%) were achieved with maximum SO2 (18 ppm) and NO (11 ppm) emission levels complying with the maximum permissible levels established in the Mexican environmental legislation (NOM-098-SEMARNAT). The proposed experimental prototype was demonstrated to be both technically and environmentally feasible for USW treatment via fluidized bed technology. Keywords: combustion, urban solid waste, fluidized bed.

Keywords

combustion, urban solid waste, fluidized bed