Development of biochar-based nanocatalysts for tar cracking/reforming during biomass pyrolysis and gasification

Gasification and pyrolysis have been considered as potential routes for the production of fuel gas from abundant, low-cost and renewable biomass materials. Tar is the undesirable but inevitable byproduct during these processes, which not only lowers the overall energy conversion efficiency but also leads to potential contamination and clogging problems. Catalytic reforming has been seen as one of the most promising methods for tar elimination, and biochar-based nanocatalysts (BBNs) show promise as an efficient tar reforming catalyst. Extensive research efforts have been devoted to the development of BBNs to reduce biomass tar below tolerable limits. This current study reviews the recent progress in the preparation and application of BBNs for converting tar into fuel gas during biomass gasification or pyrolysis. The formation and chemical characteristics of the BBNs are introduced for a better understanding of the catalytic mechanism; prospects for success, as well as challenges, are also discussed.