Experimental investigation on the combustion of bagasse, cane straw and this blends in a laboratory scale fixed bed

Abstract

In Brazil there are about 1200 sugarcane bagasse boilers, installed in the 400 (approximately) sugarcane processing plants, for the production of sugar and ethanol. More than 99% of these boilers are fixed bed, where the main types of combustion devices are the dumping grate, pin-hole fixed grate or travelling grate. Bagasse is thrown above the grate, part of this bagasse initiates the process of combustion in suspension and the larger particles are deposited on the grate forming the bed in combustion. Primary air is injected under the grate and secondary air is injected above the grate for combustion of the volatiles. Little information is available on the behavior of the bagasse in the grate, be it on the drying stages, devolatilization and combustion of the fixed carbon, or on the ash behavior. Cane straw has been considered for burning in mixture with sugarcane bagasse or even replacing it. Bagasse and cane straw have some different characteristics (shape and size, ash, presence of chlorine) and the effects of straw combustion are not yet fully predictable. This project aims to experimentally study the combustion of bagasse, straw and mixtures in a fixed bed in order to obtain combustion parameters and behavior of these biomasses in fixed bed, which are useful for the design, sizing, simulation and validation of the combustion of bagasse and straw, applied to steam boilers. (AU)