Enhanced hydrogen production from straws using microwave-assisted pyrolysis with NiO/C based catalyst/absorbent

Microwave-assisted pyrolysis from straws is one of the most promising technologies to produce green hydrogen, but its total gas yield and hydrogen yield are relatively low. In this study, the microwave-assisted pyrolysis characteristics of wheat straw, rice straw, and corn straw were experimentally investigated under different pyrolysis time, pyrolysis temperature and microwave power per unit straw mass. Results indicated that the optimal gas yield was achieved by the pyrolysis time of 25 min, the reaction temperature of 400 C and microwave power per unit straw mass of 33.3 kW/kg, and the corn straw exhibits an optimal performance of hydrogen production with a total gas yield of 58.7 % and a hydrogen yield of 25.4 %. To enhance the hydrogen production, the catalysts/absorbents based on the carbon materials and NiO/C composites were introduced. Results indicate that both carbon materials and NiO/C composites can significantly improve the total gas yield and hydrogen yield against pure straw, and the hydrogen yields using carbon materials and NiO/C composites are 1.8 and 1.9 times higher than that of the pure straw experiment respectively. This study provides a potential technology approach for hydrogen production enhancement through the microwave-assisted pyrolysis experiment using catalysts/ absorbents.