Green hydrogen production and potential evaluation via chemical looping reforming of pyrolytic volatiles from reed

• Green hydrogen is prepared by using pyrolysis series chemical looping reforming. • The feasible region of the pyrolysis products of reed was explored. • The rate-limiting steps involve methane dissociation and further ketone conversion. • The volatiles conversion was 96.46 %, and the maximum H 2 yield was 47.7 mg·g reed −1 . To achieve efficient utilization of waste resources and promote energy transition, this study selected reed, reed leaves and reed stems as raw materials and utilized pyrolysis series chemical looping reforming (CLR) technology to produce green hydrogen. The optimal pyrolysis conditions (pyrolysis raw materials, temperature) and the feasible region of products were explored. The result shows that the optimal pyrolysis raw material is the mixed reed, with a temperature of 600 ℃ (volatiles content of 76.29 % and hydrogen production of 1.73 mg·g reed −1 ). NiFe 2 O 4 oxygen carrier (OC) was used to explore the optimal operating conditions (temperature, OC dosage and steam addition amounts) for the pyrolysis and volatiles series CLR of reed. This study demonstrates that the volatiles conversion reached 95.83 % at 700 ℃ with a steam input of 0.6 ml, achieving a maximum hydrogen yield of 47.7 mg·g reed −1 . In-situ diffuse reflection infrared spectroscopy and thermogravimetric infrared analysis revealed that the dissociation of methane and the further conversion of ketone products might be the rate-limiting steps of the reaction. Furthermore, this study counted and speculated the possibility of hydrogen production from reed in the world. This study provides essential data support for the green and low-carbon hydrogen production from waste resources.