Experimental Investigation of Olive Tree Pruning Gasification in a Bench-Scale Fluidized Bed

Abstract

Olive tree pruning was gasified in a laboratory fluidized bed reactor using air as gasifying agent. Different operating temperatures (800, 850 and 900 ºC) and equivalence ratios (ER) (0.12-0.35) were tested and additional tests were performed varying the particle size of the fuel, the biomass feed rate and the oxygen content in the air (13-40%). The composition of the product gas was determined measuring light gas components (CO2, CO, CH4, H2, C2H4, C2H2, C3, N2), tar, inorganic contaminants (NH3, HCN, H2S, HCl), and water. Solid samples collected from the cyclone and the fluidized bed were also examined. It was found that for low temperature (800 ºC) the gasification efficiency was low (0.58) due to the low char conversion. On the contrary at 900 ºC, the gasification efficiency was above 70% even for the highest ER tested (0.35). The quality of the gas was significantly improved by using O2-enriched air up to 40%.