Potential to retrofit existing small-scale gasifiers through steam gasification of biomass residues for hydrogen and biofuels production

• Published in: International journal of hydrogen energy 2021-02, Vol.46 (13), p.8972-8985
• Main Authors: Piazzi, Stefano, Menin, Lorenzo, Antolini, Daniele, Patuzzi, Francesco, Baratieri, Marco
• Format: Article
• Language: English
• Subjects: Biofuels; Biomass; Hydrogen; Residues; Retrofit; Steam gasification
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.01.004

This work investigates the opportunity of retrofitting existing small-scale gasifiers shifting from combined heat and power (CHP) to hydrogen and biofuels production, using steam and biomass residues (woodchips, vineyard pruning and bark). The experiments were carried out in a batch reactor at 700 °C and 800 °C and at different steam flow (SF) rates (0.04 g/min and 0.20 g/min). The composition of the producer gas is in the range of 46–70 % H2, 9–29 % CO, 12–27 % CO2, and 2–6 % CH4. A producer gas specific production factor of approx. 10 NLpg/gchar can be achieved when the lower SFs are used, which allows to provide 80 % of the hydrogen concentration required for biomethanation and MeOH synthesis. As for FT synthesis, an optimal H2/CO ratio of approx. 2 can be achieved. The results of this work provide further evidence towards the feasibility of hydrogen and biofuels generation from residual biomass through steam gasification. •Opportunity of retrofitting existing small-scale gasifiers.•Conversion of biomass residues to hydrogen and biofuels by steam gasification.•Hydrogen in the producer gas is in the range of 46–70 %vol.•Optimal Fischer-Tropsch H2/CO ratios can be achieved with all biomass residues.•80% of the H2 required for a syngas biomethanation process can be achieved.