title: Optimization of preparative chromatographic separation of multiple rare earth elements.
abstract: This work presents a method to optimize multi-product chromatographic systems with multiple objective functions. The system studied is a neodymium, samarium, europium, gadolinium mixture separated in an ion exchange chromatography step. A homogeneous Langmuir Mobile Phase Modified model is calibrated to fit the experiments, and then used to perform the optimization task. For the optimization a multi-objective Differential Evolution algorithm was used, with weighting based on relative value of the components to find optimal operation points along the Pareto front. The objectives of the Pareto front are weighted productivity and weighted yield with purity as an equality constraint. A prioritizing scheme based on relative values is applied for determining the pooling order. A simple rule of thumb for pooling strategy selection is presented. The multi-objective optimization gives a Pareto front which shows the rule of thumb, as a gap in one of the objective functions.
authors.affiliation: Lund University, Department of Chemical Engineering, Lund, Sweden.
authors.forename: Mark
authors.initials: M
authors.lastname: Max-Hansen
authors.forename: Frida
authors.initials: F
authors.lastname: Ojala
authors.forename: Dejene
authors.initials: D
authors.lastname: Kifle
authors.forename: Niklas
authors.initials: N
authors.lastname: Borg
authors.forename: Bernt
authors.initials: B
authors.lastname: Nilsson
mesh_terms: D000465:Algorithms; D002852:Chromatography, Ion Exchange / Q000379:methods*; D003198:Computer Simulation; D008674:Metals, Rare Earth / Q000737:chemistry / Q000302:isolation & purification*; D008956:Models, Chemical
chemical_list: D008674:Metals, Rare Earth