초록 |
In this study, the model biomass was used for hydrogen production by supercritical water gasification (SCWG). Model biomasses were glycerol, glycine, lignin and cellulose. The feed concentration was set to 1 wt%. Experiments were conducted in a reactor at $440^{ circ}C$ and above 26.3 MPa for 30 min. The effects of catalysts such as alkali metal salt ( $K_2CO_3$ and $Na_2CO_3$ ) and transition metal salts ( $Ni(NO_3)_2$ , $Fe(NO_3)_3$ and $Mn(NO_3)_2$ ) on the gasification were systematically investigated. No tar or coke was observed in all experiments. The results showed that the gasification efficiency increased with various catalysts. For the cellulose and glycerol, all catalysts were effective for the promoted $H_2$ production compared with no catalyst. The significant decrease of $H_2$ production compared with no catalyst was observed with $Na_2CO_3$ and $Fe(NO_3)_3$ for glycine and lignin. respectively. The highest H2 production, 1.24 mmol was obtained for glycerol-SCWG with $Mn(NO_3)_2$ . Conclusively, the addition of $Mn(NO_3)_2$ enhanced all model biomass gasification efficiency and increased the hydrogen production promoting the supercritical water reaction. |