Development of a fluidized bed reactor for catalytic dry reforming of methane with CO₂

Experimental studies of dry reforming of methane (DRM) under bubbling regime in the thermal fluidized bed reactors (FBRs) remain limited. In this study, a thermal FBR was developed, and catalytic DRM was systematically evaluated. Nickel-supported catalysts (Ni/FCC) were prepared via a wet impregnation method using commercial fluid catalytic cracking (FCC) particles, and their physicochemical properties were comprehensively characterized. Detailed fluidization behaviour was investigated using pressure drop fluctuations and discrete wavelet transformation (DWT), revealing a transition velocity (Uc) between bubbling and turbulent regimes in the FBR (under the conditions relevant to DRM), which was found to decrease with increasing temperature. DRM performance of Ni/FCC was assessed under various reaction temperatures (600–800 °C), gas velocities (0.1–0.2 m/s), and preheating conditions. Optimal operation in the bubbling regime (800 °C, 0.1 m/s) enabled CO₂and CH₄conversions of 57% and 41%, respectively, with an H₂/CO ratio of 0.67. Comparative studies demonstrated that the packed bed reactor (PBR) achieved higher conversions and better H₂/CO ratios (∼0.96), attributed to its plug flow characteristics, whereas the FBR exhibited lower conversions due to gas back mixing and reactant bypassing. Nevertheless, the Ni/FCC catalyst exhibited good thermal stability and negligible deactivation in both reactor configurations during 20 h of continuous operation. These findings provide practical insights into the design, operation, and catalytic behaviour of FBR systems for industrial DRM applications.