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 H-2 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) x 0.06 x 1 m(3)), a steam reactor (0.16 x 0.06 x 1.4 m(3)), a riser (0.03 x 0.06 x 3.8 m(3)), two loop-seals (0.03 x 0.06 m(2)), and a cyclone. Zirconia beads (d(p)= 186 m, rho(p) = 3720 kg/m(3), U-mf = 4.95 x 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/m(2)s 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. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.