(150f) Behavior of Nanosized TiO2 Catalyst in a Microjet and Vibration Assisted Fluidized Bed

Recently, there is a growing interest in understanding the behavior of nanosized particles in gas-solid fluidized beds since fluidization is one of the most effective methods of utilizing nanoparticles. However, the presence of numerous nanosized particles leads to the formation of large agglomerates due to the large interparticle forces(e.g. electrostatic force and Van der Waals force). When using nanosized powders, particularly agglomerate bubbling fluidization (ABF) types of particles, the fluidization is described by exceptionally restricted bed expansion and large bubble formation when the minimum fluidization velocity is achieved. For these reasons, a fluidization process that combines multiple forces was used to improve fluidization quality.

From previous research, the microjet assisted fluidization technique was shown to be effective in dispersing nanosized particles. However, the past work utilized chemicals to minimize the interparticle forces. The use of chemicals to enhance the fluidization process limits the applications of the microjet nanoparticle fluidization system for environmental remediation work.

In this study, nanosized titanium dioxide (TiO2), a photocatalyst of ABF type, was selected as the test particle, due to its usefulness in pollution reduction applications. For the first time, we have studied the dual effect of vibration and a downward micro-jet on the fluidization of nanosized TiO2 fluidized. This new methodology with unprecedented MVA(microjet and vibration assisted) fluidization overcomes the problem of agglomeration of the ABF powder. The fluidization quality, as measured by the parameters of non-dimensional bed height, non-dimensional pressure drop, and controlled particle distribution were determined. This works shows the results of laboratory data to show the usefulness of the new MVA method over microjet fluidization, thereby enabling new applications in chemical reaction engineering employing photocatalysts and environmental remediation.