NSF Award
8960184
Photochemical reactions of compounds absorbed in or absorbed on solids is in an early stage of development as a means of producing useful chemicals on an industrial scale. This process can be used for example for photofixation of nitrogen and photo-oxidations, isotopic enrichment, photochlorination, as well as other chemical synthesis. This Small Business Innovation Research Phase I is aimed at exploring the commercial viability of using a rotating fluidized bed with a light source at the core, as a high efficiency photochemical reactor. A rotating fluidized bed is essentially a vertical cylinder with porous walls which rotates around its axis of symmetry. The particulate matter is forced against the wall due to the large centrifugal forces produced by the rotation. The wall serves as a gas distributor for the bed and the gas flows radially inward through it and through the bed particles. When the drag forces on the granule balance the centrifugal forces, the bed becomes fluidized. The system to be developed will be designed with a lamp in the core and with the facility for addition and removal of solid during the reaction. These rotating fluidized beds should be adaptable to the use of solar energy. The sunlight could be collected and be transferred with mirrors or through fiber optic bundles to the reactor. This could be done for purely solar sytems or in combination with artificial light for systems that require continuous operation. Specific research objectives for Phase I are: . Design and build a prototype rotating photochemical fluidized bed reactor. . Determine the relative quantum efficiency of the rotating bed vs. the parallel plate bed using well understood photochemical reactions. . Determine the effects of variables, such as speed of rotation, fluidizing gas flow rates and particle size, on quantum efficiency. . Develop theoretical models for the photochemical rotating fluidized bed for design of the second generation systems. . Evaluate the rotating bed for both isotopic enrichment and photochlorination technologies.
