(228e) Development of a Triple-Bed Combined Circulating Fluidized Bed

We have developed a novel triple-bed combined circulating fluidized bed (TBCFB) gasifier which was originally proposed by Professor Atsushi Tsusumi. In this TBCFB, a downer pyrolyzer, a bubbling fluidized bed gasifier, and a riser char combustor are integrated to increase thermal efficiency of gasification at low temperatures. In this talk, we will explain 1) hydrodynamic behaviors of silica sand at very large solids circulation rate (Gs=300-500 kg/(m2 s)) in the TBCFB cold model (downer (d:0.1 m, height: 6.5 m), a bubbling fluidized bed (0.75 m×0.27 m×1.9 m), a riser (d: 0.1 m, height: 16.6 m) and a gas-sealing bed (GSB: d: 0.158 m×5 m), 2) hydrodynamics of the solids in the downer, 3) reactivity of lignite in a lab-scale downer pyrolyzer (d: 0.020 m×1 m), and 4) theoretical limit of cold gas efficiency in this TBCFB gasifier.