Hydrodynamics of a Novel Design Circulating Fluidized Bed Steam Reformer Operating in the Dense Suspension Upflow Regime
Table 1
Comparison between fixed bed steam reformers, bubbling fluidized bed steam reformers (BFBMSR), and circulating fluidized bed membrane steam reformer (CFBMSR).
Fixed bed
BFBMSR
CFBMSR
Catalyst particle size (for the same flow rate)
Large to decrease pressure drop (8–16 mm)
Relatively larger than that of CFBMSR (0.2–0.35 mm)
Fine particles are used ensuring higher effectiveness factor (0.05–0.15 mm)
Pressure drop
Very high (2–4 atm)
Moderate (0.2–0.4 atm)
Low (around 0.1 atm)
Effectiveness factor
Very low (10−2–10−3)
High (~1)
High (~1)
Gas flow rate
Low
Medium
High, allowing for higher productivity
Catalyst regeneration
Shutdown required
Shutdown typically needed
No need for shutdown due to the presence of downer; also regeneration allows autothermicity of the operation
