Abstract:In this experimental study the evolution of gas characteristics during the gasification of olive bagasse particles was investigated using a semi-batch fluidized-bed gasifier. Sand particles with a mean diameter of 375 μm were used as bed material and an air flow was used as the fluidizing agent. Experimental tests were conducted with particles of diameter ranging from in 1.25 to 2 mm. The material was characterised through elemental and proximate analysis, and the higher heating value was also measured. In each run, the major components of the gas phase were identified as CO, CO2, H2, CH4, O2 and N2. Gaseous samples were collected and analysed by gas chromatography. The effect of bed temperature on gasification performance was studied. The tests were conducted at bed temperatures in the range of 700ºC to 900ºC Experimental results showed that gasification with air at higher temperatures favoured gas production, Results also showed increases in the gasification performance parameters as the bed temperature is increased.

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Due to the lack of reliable mathematical models for predicting the minimum spouting velocity in spouted bed dryers, in this work a new model is proposed that takes into account the effects of adhesive forces acting on particle agglomerates due to the presence of pastes. The results are compared with experimental data reported by Spitzner and Freire (2001), obtained by the continuous feeding of egg paste into a spouted bed, and with additional data obtained for batch feeding of glycerol into the same bed. The equipment was a conical spouted bed with a 0.05 m inlet diameter, a 60° cone angle, and a 0.21 m cone height. Glass spheres with a diameter of 2.6x10-3 m were used as inert particles. It was observed that as saturation increases, the minimum spouting velocity increases for egg paste and decreases for glycerol. The results indicate that there are different forces acting on the bed of particles depending on the paste and operating conditions. The mathematical model provided good predictions only for egg paste, although the values for minimum spouting velocity were slightly overestimated

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