Evaluation of downer reactor performance by catalytic ozone decomposition

Radial distribution profiles of ozone concentrations were measured along an 8.50 m high and 0.09 m inside diameter gas/solid co-current down-flow circulating fluidized bed (downer) to characterize the reactor performance. Tests were conducted under a series of operating conditions at room temperature and near atmospheric pressure, with FCC particles as the bed material. Results show that the concentration distribution of the ozone tracer gas correlates well with the flow structure of the downer. There is quite a uniform radial distribution of ozone concentrations in the core region of all tested axial sections in the fully developed region of the downer, except for the near-wall region where there is a sharp decrease in ozone concentration. And there exists a relatively significant non-uniform distribution in the entrance acceleration region of the downer.