Gas reforming and tar decomposition performance of nickel oxide (NiO)/SBA-15 catalyst in gasification of woody biomass

In the gasification of biomass, it is necessary to limit the amount of by-product tar and increase the yields of hydrogen (H₂) and carbon monoxide (CO) (syngas). Therefore, we conducted gasification and reforming experiments on woody biomass using an electric tubular furnace, to evaluate the gas reforming and tar decomposition performance of a NiO/SBA-15 catalyst. As a result, we found that this catalyst is effective for H₂ production. It is believed that the increase in H₂ volume due to the catalyst occurs through a steam reforming reaction involving hydrocarbons, including methane (CH₄), and the water-gas shift reaction. With respect to the influence of the gasifying agent on the reforming effect of the catalyst, the amount of generated carbon dioxide (CO₂) and hydrogen (H₂) increases because the shift reaction is promoted by supplying steam. On the other hand, it was inferred that the shift reaction rarely occurred because it approaches equilibrium by supplying O₂. Furthermore, it is suggested that light aromatic hydrocarbons are decomposed by the catalyst.

Implications: The mesoporous silica catalyst NiO/SBA-15 was highly effective for H₂ production and decomposition of light aromatic compounds in the gasification of woody biomass. In the catalyst reaction, supplying steam promoted H₂ production. From thermodynamic analysis and discussion, it was also inferred that supplying O₂ might prevent the water gas shift reaction. The results are useful for designing a process needed for rich H₂ production and gas refining process for further use of syngas.