Tunable Syngas Production from Biomass: Synergistic Effect of Steam, Ni-Cao Catalyst, and Biochar

The acquisition of tunable syngas through the inherently separated generation of high purity H2 and CO from biomass will further establish the role of biomass-derived syngas as a versatile platform for liquid fuels and value-added chemical synthesis. The influence of steam, Ni-CaO catalyst, and biochar on the tunable syngas generated from sewage sludge via a two-stage sorption-enhanced (TSSE) thermochemical conversion process was studied in this study. The presence of steam and Ni-CaO catalyst shows unprecedented performance in enhancing the H2 generation at the first stage, and the control experiments indicate that the steam performs a higher selectivity to H2 than the Ni-CaO catalyst. The introduction of biochar supplements carbon source for CO production, remarkably promoting the CO generation at the second stage, which could be further pronounced by the addition of Ni-CaO catalyst. A synergistic effect of steam, Ni-CaO catalyst, and biochar contributes to a significant enhancement in H2 and CO generation with an inherently separated generation of H2 (88.2 vol% of purity) and CO (55.6 vol% of purity). And the combined use of steam, Ni-CaO catalyst, and biochar could lead to a superior syngas quality with high LHVsyngas and energy recovery efficiency.