Enhancing hydrogen production from biomass pyrolysis by dental-wastes-derived sodium zirconate

Sodium zirconate was synthesized via the solid-phase reaction from dental wastes with sodium carbonate. The dental-wastes-derived sodium zirconate (DW-SZ) dramatically enhanced hydrogen (H-2) production during biomass pyrolysis due to the presence of alkali metal (Na) and in-situ carbon dioxide (CO2) capture. To be specific, the DW-SZ could maintain a maximum CO2 uptake of 0.195 g-CO2 g-sorbent(-1) at the 30th cycle under cyclic CO2 absorption/desorption swings. The total CO2 uptake in all 30 cycles reached 82% of the theoretical CO2 uptake. The synthesized functional material was subsequently employed for H-2 production in the pyrolysis of three different biomass samples (i.e., municipal sludge, spirulina, and methylcellulose). The highest H-2 yield of 205 ml g(-1) was produced by spirulina in presence of functional material, followed by methylcellulose (197 ml g(-1)), and municipal sludge (142 ml g(-1)). Moreover, the DW-SZ was characterized by XRD, BET and SEM to help unravel and justify the underlying reaction mechanisms. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.