Two-step gasification of cattle manure for hydrogen-rich gas production: Effect of biochar preparation temperature and gasification temperature

Two-step gasification process was proposed to dispose cattle manure for hydrogen rich gas production. The effect of temperature on product distribution and biochar properties were first studied in the pyrolysis-carbonization process. The steam gasification of biochar derived from different pyrolysis-carbonization temperatures was then performed at 750 °C and 850 °C. The biochar from the pyrolysis-carbonization temperatures of 500 °C had high carbon content and low volatiles content. According to the results of gasification stage, the pyrolysis-carbonization temperature of 500 °C and the gasification temperature of 850 °C were identified as the suitable conditions for hydrogen production. We obtained 1.61 m3/kg of syngas production, 0.93 m3/kg of hydrogen yield and 57.58% of hydrogen concentration. This study shows that two-step gasification is an efficient waste-to-hydrogen energy process.