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

Experimental studies of dry reforming of methane (DRM) under the bubbling regime in 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 (U₍c₎) 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⁻¹), and preheating conditions. Optimal operation in the bubbling regime (800 °C, 0.1 m s⁻¹) enabled CO₂ and CH₄ conversions 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.<br/><br/>These findings provide practical insights into the design, operation, and catalytic behaviour of FBR systems for industrial DRM applications.