Moreover, Fig. and Table illustrate that the total CO production decreased significantly with the elevation of the steam supply. These findings implied that higher steam amounts in the gasification system favored the suppression of the percentage of reaction 1. Furthermore, the increase in steam supply rate slightly decreased the methane content in the syngas, suggesting that higher steam amounts promoted the conversion of methane to CO2 and H2 (Table ). Moreover, both hydrogen releasing rate and yield were positively associated with the steam supply (Fig. and Table ).