High hydrogen content syngas for biofuels production from biomass air gasification: Experimental evaluation of a char-catalyzed steam reforming unit

This work investigates the performance of a reformer reactor for the upgrading of syngas and char derived from a pilot-scale air gasifier. The proposed setup represents a circular approach for the production of hydrogen-rich syngas from air gasification. Specifically, the reforming-unit was operated under a range of temperatures (from 700 degrees C to 850 degrees C) and steam flow rates and for each the improvement in producer gas composition and reducing species yield is evaluated. The results highlight that an increase in hydrogen concentration is obtained at higher temperature, moving from 16.2% to 21.3%, without using steam, and to 45.6%, with steam injection on the char-bed, while CO concentration did not follow a monotonic behavior. Moreover, the gas quality index, defined as a ratio between reducing species and inert species, delivered the highest values at the highest temperatures and steam flow rates. These results provide a guide for future gas quality optimization studies. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.