Experimental Assessment of Woody Biomass Gasification in a Hybridized Solar Powered Reactor featuring Direct and Indirect Heating Modes

International audienceSolar thermochemical gasification is an opportunity for the production of sustainable fuels from carbonaceous resources including biomass. Substituting conventional gasification processes by solardriven technologies may enable cleaner production of H 2-rich syngas while saving feedstock resources and alleviating CO 2 emissions. This work addresses hybrid solar-autothermal gasification of mm-sized beech wood particles in a lab-scale 1.5 kW th spouted-bed reactor. Hybridization under reduced solar power input was performed by injecting oxygen and additional biomass inside the gasifier for complementary heat supply. Increasing O 2 :C molar ratios (in the range 0.14-0.58) allowed to heat the reactor cavity and walls progressively, while gradually impairing the reactor performance with an increase of the syngas CO 2 content and a decrease of the reactor cold gas efficiency (CGE). Gasification with mixed H 2 O and O 2 was then assessed at thermodynamic equilibrium and global trends were validated experimentally, showing that control of H 2 :CO ratio was compatible with in-situ combustion. The impact of reaction temperature (1200-1300°C) and heating mode (direct or indirect) was experimentally studied during both allothermal and hybrid gasification. Higher H 2 and CO yields were achieved at high temperatures (1300°C) under direct reactor heating. Hybridization was able to counterbalance a 40% drop of the nominal solar power input, and the measured CGE reached 0.82, versus values higher than 1 during allothermal gasification