Modeling REE binding of lanmodulin to guide separation optimization

diagram illustrates reaction network for cooperative binding of LanM to binary pair of REEs.
Reaction network for cooperative binding of LanM to binary pair of REEs.

CMI researchers from Lawrence Livermore National Laboratory conducted the activity for this highlight

Innovation 
Developed and validated a mathematical model for binding REE to the two principal coordination sites of the bacterial protein lanmodulin.

Achievement
Characterized lanmodulin binding to pairwise combinations of 10 REEs over a range of concentration ratios. Homogenous and heterogenous equilibrium binding coefficients were derived from binary REE binding data through model fitting. Enabled accurate prediction of equilibrium distribution of REEs bound to lanmodulin from a range of feedstocks.

Significance and Impact

  • This is an important first step in developing a process model for use in designing and scaling lanmodulin-based REE separations.
  • Next steps: expand model development toward kinetic model for on-column REE adsorption and desorption.

Hub Target Addressed 
Developing highly selective separation from complex sources.

diagram for predicting equilibrium composition of REEs bound to LanM from simulated feedstock. Gray and black bars show the fractional composition of the feedstock and the recovered REE mixture. Each colored segment shows the predicted fraction of REE bound with a second lanthanide as shown in the legend.
Predicting equilibrium composition of REEs bound to LanM from simulated feedstock. Gray and black bars show the fractional composition of the feedstock and the recovered REE mixture. Each colored segment shows the predicted fraction of REE bound with a second lanthanide as shown in the legend.