Synthesis of nickel/biochar composite from pyrolysis of Microcystis aeruginosa and its practical use for syngas production

[Display omitted] •CO2/microalgae were converted into both syngas and biochar.•CO2 expedited a reaction with VOCs, resulting in enhanced syngas formation.•Biochar produced from pyrolysis showed a catalytic capability for pyrolysis.•Ni impregnated biochar significantly promoted CO and H2 production. This study proposes a sustainable waste-to-energy/biochar platform using a toxic microalgal biomass waste. In particular, CO2-feeding pyrolysis of Microcystis aeruginosa (M. aeruginosa) waste was investigated, focusing on the analysis of gaseous pyrolysates and properties of biochar with a construction of mass balance. Also, the catalytic capability of biochar produced from M. aeruginosa was explored to reinforce the mechanistic impact of CO2 on the pyrolysis process within the overall process level. Ni impregnated biochar composite was further synthesized and used as a catalyst to promote syngas formation in the CO2-feeding pyrolysis process of M. aeruginosa.