Syngas production by bio-oil steam gasification in a fountain confined conical spouted bed reactor

Abstract

The combination of delocalized units for the fast pyrolysis of biomass to produce bio-oil followed by centralized units for the gasification of bio-oil appears as an economically attractive option for the full-scale production of syngas because transportation of bio-oil is less costly than that of biomass. First goal of this study lies in the validation of a bio-oil feeding device made up of a line-thermostated at 60–80 °C and a non-atomizing injector cooled by water. This injector allows feeding the crude bio-oil in continuous mode into the conical spouted bed reactor without being clogged by the pyrolytic lignin in the bio-oil. The effect of gasification temperature on gas properties, tar composition, and carbon conversion efficiency were assessed in the 800–900 °C range. The results show that temperature promotes tar reduction (from 40.7 to 12.5 g/Nm3), carbon conversion efficiency (from 91.2 to 96.3 %) and gas yield (from 1.37 to 1.85 Nm3/kg on a dry basis) as temperature is increased from 800 to 900 °C. A novel aspect of this study is the detailed characterization of the tar evolution with temperature, which, to our knowledge, is an aspect that has not been approached in the literature related to raw bio-oil gasification.