Improving catalyst performance of Ni-CaO-C to enhance H2 production from biomass steam gasification through induction heating technology

Abstract

Catalyst performance plays a key role in biomass gasification for H2 production. In this study, induction heating technology was proposed to in-situ heat Ni-based catalyst via Joule heating effect to improve the catalyst performance during steam gasification of biomass for enhancing H2 production. Scanning electron microscope, Brunauer-Emmett-Teller, Thermogravimetric analysis and X-ray diffraction analysis confirmed that less coke deposition, larger specific surface area and more active sites of Ni particles with better crystallinity degree were observed for the used Ni-CaO-C catalysts in induction heating reactor compared to conventional heating reactor (Electric resistance heating). Thus, Ni-CaO-C catalyst in induction heating reactor showed significantly higher catalyst performance, and the H2 production was greatly enhanced from 591–692 mL/g-biomass to 1097–1325 mL/g-biomass (increase rate up to 101.1 %). Furthermore, adding metallic particles into catalyst bed in induction heating reactor can also promote the catalyst performance and then enhanced H2 production. By using induction heating catalytic technology coupled with metallic particles addition, all the H2 yields from steam gasification of four typical biomass (reed straw, wheat straw, corn cob and rice husk) were increased (increase rates reached 106.6–133.5 %) compared to conventional heating reactor. And the ranking of the positive effects of Ni and metallic particles via induction heating on enhancing H2 production was as follows: Ni + Metallic particles coupling effect > Ni effect > Metallic particles effect. Under the optimal conditions, the H2 yields from these four biomass were as high as 1803, 1805, 1722 and 1740 mL/g-biomass, respectively.