Optimization of a fluidized bed reactor for methane decomposition over Fe/Al2O3 catalysts: Activity and regeneration studies.

Catalytic methane decomposition was investigated over 40 wt% Fe/Al 2 O 3 catalyst in fluidized bed reactor (FLBR). After optimization of FLBR conditions in terms of catalyst bulk density, particle size, minimum fluidization velocity, and the catalyst bed height, the catalyst activity and stability tests were conducted by comparison with a fixed bed reactor (FBR). Although a similar stable methane conversion was obtained over both reactors, the pressure drop during 35 min operation of FBR was 9 times higher than that of FLBR, which indicated the possibility of continuous operation of methane decomposition process over FLBR. Further, the influence of the space velocity, feed dilution and regeneration on catalysts reactivity was studied in FLBR to conclude that a reaction condition of 12 L/g cat ∙h, feed of 20%H 2 –80%CH 4 and CO 2 -regeneration of deactivated catalysts may be favourable for operating methane decomposition in FLBR continually and effectively to provide stable hydrogen. Catalytic methane decomposition was investigated in a fluidized bed reactor over 40 wt% Fe–Al 2 O 3 catalysts, and optimized the reaction conditions of the fluidized bed reactor. Subsequently, the deactivated catalysts were regenerated by CO 2 oxidation at 750 ̊C. Image 1 • Comparison methane conversion and pressure drop between fluidized and fixed bed reactor. • Optimization of reaction parameters in fluidized bed reactor over 40 wt% Fe/Al 2 O 3 catalysts. • Improved performance of methane conversion over regenerated catalysts by CO 2 oxidation. • Producing bamboo shaped and straight carbon nanotubes over fresh and regenerated 40 wt% Fe/Al 2 O 3 catalysts. [ABSTRACT FROM AUTHOR]