(245c) Adsorption Modeling for Selective Capture of Uranium from Seawater

Authors: 
Ladshaw, A., Georgia Institute of Technology
Yiacoumi, S., Georgia Institute of Technology
Tsouris, C., Oak Ridge National Laboratory
One of the world’s rising global issues is how to meet the necessary energy demands of tomorrow without destroying the resources and environment of today. This challenge is being met by research into solar and wind energy, biofuels, and nuclear power. To facilitate the use of nuclear power in place of more traditional fossil-energy sources may require the utilization of the ocean as a new source of uranium. Adsorption technology can be employed to farm uranium from seawater in order to provide a new, untapped source of fuel for nuclear power. The ocean has the potential to provide a vast amount of uranium to add to the nuclear fuel cycle, as it contains nearly 1000 times more uranium than conventional mines. However, the average concentration of that resource is roughly 3.3 ppb, which presents a technological challenge. Recently, a significant effort has been focused on the utilization of amidoxime ligands for the selective removal of uranium from seawater, but there are still many other environmental factors such as pH, temperature, competing ions, and current flows that further complicate the design of a capture system. The realization of the ocean uranium recovery system will require an advanced understanding of the physical-chemical processes involved, as well as a set of engineering modeling tools to aid in the process design. An advanced modeling framework coupled with detailed, high-resolution adsorption process models is being developed in order to give engineers a reliable design tool for the implementation of a seawater-capture system. These process models are coupled with reaction schemes developed using ab initio methods and have been shown capable of predicting uranium uptake under laboratory conditions for specific adsorbents.