M Carolina Cruz, MA Golato, G del H Zamora Rueda, S Casen and M Ruíz
Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Av. William Cross 3150, CP 4101, Tucumán, Argentina; ccruz@eeaoc.org.ar
To evaluate fibrous sorghum as a potential alternative fuel in bagasse boilers and compare it with other biomass types, 15 samples of a commercial Silero-type hybrid (high fiber), 15 samples of bagasse from sugar mills, and 15 samples of RAC (agricultural harvest residue) were analyzed. Their physicochemical and energetic characteristics were determined, as well as the fusibility and chemical composition of their ashes, to calculate their behavior indices. Sorghum presents a high risk of slagging, as its characteristic RB/A index was greater than 0.75. All these biomasses would present a risk of sintering, as the IS index is below 2. All materials would visibly exceed the threshold value for the Fouling Index (AI), indicating a risk of fouling, although sorghum would show a lower impact compared to bagasse (15.87 < 36.27). The fusibility analyses of sorghum ashes indicated low melting points compared to bagasse, probably due to the higher K2O content (27.10%), so its use as an alternative fuel could only be as mixtures with bagasse. Acceptable behaviors were found for mixtures of 20% sorghum/80% bagasse; with these proportions, more convenient ash fusibility temperatures would be achieved to avoid problems inside the boiler and tubular bundle.