Microfibrous entrapment of Ni/Al ₂O ₃ for dry reforming of methane: Heat/mass transfer enhancement towards carbon resistance and conversion promotion

An 8-μm-copper microfibrous entrapped Ni/Al ₂O ₃ (Cu-MFE-Ni/AlO) composite catalyst was developed for demonstrating the process intensification effectiveness of the novel microfibrous entrapment technology on dry reforming of methane (DRM), which is highly regarded for CH ₄ utilizing and CO ₂ chemical cycling. Computational fluid dynamics (CFD) calculation was employed to illustrate the significant enhancement of the heat transfer of the microfibrous structured bed at steady working state. The results indicated that the average bed temperature of Cu-MFE-Ni/AlO was 1039 K, 75 K higher than that of packed bed with Ni/AlO (PB-Ni/AlO), when the wall temperature was set at 1073 K. As a result, carbon resistance of the catalyst bed was significantly improved by a thermodynamic way along with visible conversion promotion. For instance, at temperature of 1073 K, more than 4-fold reduction of average carbon deposition rate was achieved in the Cu-MFE-Ni/AlO composite bed compared to the PB-Ni/AlO, while the CH ₄ conversion was promoted from 84% on the PB-Ni/AlO to 89% on our Cu-MFE-Ni/AlO composite bed with a gas hourly space velocity (GHSV) of 20,000 mL g _cat ^-1 h ^-1. Moreover, such microfibrous entrapment technology also provided a unique combination of small catalyst particle size (0.15-0.18 mm) and entirely open structure with large void volume (71.3 vol%) thereby leading to enhanced mass transfer and high permeability (low pressure drop).