Preparing hydrogen-rich syngas by chemical looping reforming of wheat straw pyrolysis volatiles via NiFe₂O₄@SBA-15 oxygen carrier

For achieving green and low-carbon production of hydrogen-rich syngas from biomass, a nano-NiFe₂O₄ oxygen carrier embedded in molecular sieve was developed for the chemical-looping reforming of wheat straw pyrolysis volatiles. Thermodynamic analysis showed that the feasible reforming temperature should exceed 548 ℃. The optimal process parameters were established through systematic experimental studies combined with response surface methodology. The embedded strategy remarkably enhanced partial oxidation performance, resulting in a 43.3% increase in syngas yield, 98.7% conversion of volatile macromolecules, and 72.1% syngas selectivity under optimal conditions. Steam introduction effectively suppressed carbon deposition and enhanced hydrogen yield, while it is unfavorable to transforming macromolecular components compared to dry reforming conditions. Ten cycles showed that the oxygen carrier had excellent cycle stability, the volatiles conversion was 97.5–99.5%, and syngas selectivity was 70.3–72.7%, realizing the efficient conversion of volatiles. It provided necessary data for the green and low-carbon preparation of hydrogen-rich syngas and the development and design of oxygen carriers.