High efficient conversion of CO2-rich bio-syngas to CO-rich bio-syngas using biomass char: a useful approach for production of bio-methanol from bio-oil

A novel approach for high efficient conversion of the CO2-rich bio-syngas into the CO-rich bio-syngas was carried out by using biomass char and Ni/Al2O3 catalyst, which was successfully applied for production of bio-methanol from bio-oil. After the bio-syngas conditioning, the CO2/CO ratio prominently dropped from 6.33 to 0.01–0.28. The maximum CO yield in the bio-syngas conditioning process reached about 1.96 mol/(mol CO2) with a nearly complete conversion of CO2 (99.5%). The performance of bio-methanol synthesis was significantly improved via the conditioned bio-syngas, giving a maximum methanol yield of 1.32 kg/(kgcatalyst h) with a methanol selectivity of 99%. Main reaction paths involved in the bio-syngas conditioning process have been investigated in detail by using different model mixture gases and different carbon sources.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► A new catalytic conversion of CO2-rich bio-syngas using biomass char was proposed. ► A novel electrochemical catalytic conditioning of the bio-syngas was proposed. ► The conditioning can significantly decrease CO2/CO ratio in the bio-syngas. ► The performance of bio-fuel synthesis was greatly improved after the conditioning. ► Ni and the thermal electrons play an important role in the dissociation of CO2.