Experimental assessments on different waste feedstocks in a bfb gasifier

This work reports the experimental comparative study between two residual biomasses (Citrus peels and beached Posidonia Oceanica) and a traditional woody feedstock (White pine) through TG-DTG analysis and gasification measurements performed at 1023 K, 1 bar, Equivalence Ratio equal to 0.3, and different Steam to Biomass inlet ratio (0.0-1.0). These biomasses could represent important renewable sources for energy purpose, enhancing local economies and being a good path for reducing residues/waste landfilling. Thermo-gravimetric analysis reveal a shift of the peaks corresponding to hemicellulose, cellulose and lignin compounds to lower temperatures both Citrus peels and Posidonia Oceanica DTG graphs than White pine DTG profiles probably due to the interaction of lignocellulosic compounds with other molecules of the biomass structures. Gasification measurements highlight that increasing the Steam to Biomass inlet stream an increasing of syngas and H yields can be obtained for all biomasses investigated. Posidonia Oceanica gasification tests showed the best yield rates of syngas (2.70 Nm/kg) and hydrogen (0.65 Nm/kg) at Steam to Biomass equal to 1 wt/wt, however the gasification of Posidonia Oceanica has exhibited lower Cold Gas Efficiency, Carbon Conversion Efficiency and Lower Heating Value syngas values than Citrus peels gasification in all range of Steam to Biomass ratio.