From lab to industry: Scaling-up Fe-Ni bimetallic nano oxygen carrier for mid-temperature methane chemical looping reforming

Chemical looping methane reforming has emerged as a promising avenue to produce blue hydrogen. Currently, satisfactory CH4 conversion and H2 productivity typically requires reaction temperature above 800 °C, bringing challenges for industrial reactor design and energy conservation. To realize high chemical looping methane reforming performance at low temperature, a Fe-Ni bimetallic nano oxygen carrier was presented, along with the workflow and platform for scaled-up synthesis of the oxygen carrier. On account of the synergy of nanoscale Fe-Ni species, the operating temperature could be lowered to 500–600 °C. The lab-scale oxygen carrier converted >90 % CH4 and produced 3.5 H2 per CH4 molecule with 80–82 % outlet H2 purity at 575–600 °C. The 10-kg scale synthesized oxygen carrier powder exhibited >90 % CH4 conversion, >78 % H2 purity and produced 2.8–3.5 H2 per CH4, with performance penalty from scaling up controlled within 5 %. After shaping and calcination, the 10-kg oxygen carrier beads still produced 2.8 H2 from per CH4 molecule with >70 % H2 purity. Longevity test revealed the 10-kg powder and beads as stable in phase, morphology, and redox activity over 110 cycles. Experiments of variable operating conditions found that the 10-kg oxygen carriers can meet industrial requirements of H2 production at >550 °C, with low steam/carbon ratio favored by 10-kg beads. Further analysis attributed the performance distinction of 10-kg beads to its lower surface area, reduction extent and steam affinity, compared to those of the lab-scale and 10-kg powders. These findings contributed to the mid-temperature chemical looping methane reforming by bridging laboratory practices and industrial application.