Scientific Publication: Design and validation of reactant feeding control strategies for the solar-autothermal hybrid gasification of woody biomass

CNRS-PROMES and CEA published a scientific publication about SFERA-III in the September 2022 edition of the international Energy journal. The paper is available in open access.

Abstract

Several hybridization strategies of a solar-autothermal biomass gasifier were examined for stable and continuous operation under variable solar irradiation. The ultimate objective was to demonstrate the feasibility of controlled syngas production, through the modification of oxygen, water, and biomass injection rates. Various hybridization strategies were probed by thermodynamic analysis and experimentally validated. Thermodynamic equilibrium calculations detailed the impact of both H₂O and O₂ injection rates on the produced syngas composition under constant wood feeding. Oxygen injection decreased the H₂:CO molar ratio, while reducing the solar thermal power required to carry out the gasification reaction. Meanwhile, the total H₂+CO production dropped by 1.36 mol of H₂ and 0.64 mol of CO per mole of O₂ added, independently of the quantity of water provided. Validation experiments were then carried out under real concentrated solar flux in a directly-irradiated conical spouted-bed reactor, following distinct hybridization paths. Maintaining constant the H₂:CO ratio above 1 during hybridization required to provide high amounts of water steam with oxygen, which penalized the gasifier efficient heating. In contrast, minimizing the water injection rate throughout hybridization strongly altered the H₂:CO ratio but decreased the CO₂ production and the solar thermal power requirement. Finally, the successful control of the outlet H₂+CO volume flow rate with simultaneous oxygen and wood injection was demonstrated (under constant water feeding rate). Solar-to-fuel efficiencies were kept around 20%, while hybridization decreased the cold-gas efficiency below 80%.

References

Title Design and validation of reactant feeding control strategies for the solar-autothermal hybrid gasification of woody biomass

Authors Axel Curcio, Sylvain Rodat, Valéry Vuillerme, Stéphane Abanades

Cite as Axel Curcio, Sylvain Rodat, Valéry Vuillerme, Stéphane Abanades, Design and validation of reactant feeding control strategies for the solar-autothermal hybrid gasification of woody biomass, Energy, Volume 254, Part C, 2022, 124481, ISSN 0360-5442, https://doi.org/10.1016/j.energy.2022.124481.