Fluidization of micro-interconnected fluidized beds for chemical looping

Abstract

The micro-interconnected fluidized bed (MIFB) was designed to improve the evaluation condition of oxygen carrier, which is difficult to perform in a lab-scale interconnected fluidized bed because of the large demand for bed inventory. The reduction of bed inventory in the MIFB was mainly achieved by the appropriate miniaturization of the reactor size, in which the wall effect and operating flexibility should be taken into consideration. With hematite serving as the oxygen carrier, stable and flexible fluidization could be realized with 342.9g of bed inventory. Internal perforated plates were arranged in the middle of the reactor to improve gas–solid distribution, which also could restrain the slugging formation and increase the particle residence time by 28.9%. A different fluidization phenomenon was observed in this two-stage reactor in which the particle fluidization was reconstructed in the upper chamber. Throughout 48h of cold operation, the hematite oxygen carrier attrition rate was evaluated as 0.151wt.%/h corresponding to 660h lifetime, where 12.5% of particle attrition was contributed by internal perforated plates. An excellent fitting performance was found between the pressure difference in the risers and the upward particle flow, but the correction factor should be adjusted according to the fluidization flow.