Solid mass flux in a chemical-looping process for hydrogen production in a multistage circulating moving bed reactor

Abstract

We studied the solid flow characteristics of a multistage circulating moving bed reactor manufactured to produce high purity H2 using a chemical-looping process at high temperature. The reactor was constructed of stainless steel 304 and comprised an inclined fuel reactor ((bottom: 0.07 m, top: 0.16 m) × 0.06 × 1 m3), a steam reactor (0.16 × 0.06 × 1.4 m3), a riser (0.03 × 0.06 × 3.8 m3), two loop-seals (0.03 × 0.06 m2), and a cyclone. Zirconia beads (dp = 186 m, ρp = 3720 kg/m3, Umf = 4.95 × 10−2 m/s, Geldart classification B Group) were used as the bed material. To distribute compressed air, a bubble cap was used as the distributor. Solid mass flux appeared at 6.2–56.4 kg/m2s and the solid mean residence time appeared 92.5–889.3 s in the steam reactor and 75.3–717.7 s in the fuel reactor. Solid mass flux increased with increasing inlet gas velocity into the loop-seal, temperature and the bed height of the steam reactor. However, the solid mean residence time decreased with increasing inlet gas velocity into the loop-seal and the bed height of the steam reactor.