(421af) A Gas Mixing Study in a Fluidized Bed with Various Compartmented Wind Boxes

The various kinds of fluidized bed reactor with unique configurations, such as circulating fluidized bed, dual fluidized beds, compartmented fluidized beds etc., have been developed and operated in various fields, such as chemical looping combustion, CO₂ capture, biomass gasification and Redox systems.

In our previous study, for simple and good operability, the partitioned fluidized beds processes were suggested for gasification applications. The basic concept was dividing a fluidized bed into two parts, a gasifier and a combustor, by a partitioned wall. Using those systems, thermal energy can be easily transferred from high temperature zone to the low temperature zone by solid mixing. At the same time, gas mixing between two zones are minimized by an installed partitioned wall.

In this study, in order to limit gas mixing and to improve solid mixing, we installed newly developed partitioned distributors and compartmented wind boxes into the previous suggested partitioned fluidized bed reactor and compared gas mixing behaviors with the previous systems. Various kinds of partition configurations were located above the distributors. And the air boxes were compartmented with walls. The partitioned distributors and the compartmented air boxes play roles as the multiple loop seal systems.

The advantages of newly developed fluidized bed reactors are: 1) minimizing gas mixing, 2) improving solid mixing, 3) improving thermal efficiency, 4) easy controlling contact time and residence time, 5) two separated bubbling operation. The disadvantages of them are: 1) complicated operation, 2) difficult overhaul.

It can be applied to the two reactor systems such as chemical looping combustor (combustion and reduction) and biomass dual fluidized bed gasifier systems (combustion and gasification) etc.