Efficient Separation of Glutamic Acid by the Sequential Simulated Moving Bed Coupled Crystallization Process: Parameter Determination, Process Design, and Multiobjective Optimization

In order to solve the problems encountered during the separation and purification of glutamic acid, including low product purity, high solvent consumption, interference from structurally similar impurities affecting adsorption efficiency, and wastewater generation, an innovative coupling process combining sequential simulated moving bed (SSMB) chromatography with crystallization was developed in this work. The adsorption isotherms and kinetics of glutamic acid mixture were first determined through pulse experiments and frontal analysis. The initial operating conditions of the SSMB were designed using triangle theory based on the measured parameters. Meanwhile, the products obtained during the feeding stage of the SSMB process were integrated into a crystallization coupling design. The Nondominated Sorting Genetic Algorithm II (NSGA-II) was used for multiobjective optimization to simultaneously improve the purity, recovery, and throughput of glutamic acid while reducing solvent consumption. Experiments demonstrate that the purity of glutamic acid separated using the optimized SSMB process exceeds 97%. Furthermore, the implementation of a coupled crystallization process enhances the purity to 99%, resulting in the formation of α-type crystals with well-defined morphologies. The mother liquor will be recycled to SSMB, thereby achieving an efficient and environmentally friendly separation purpose, which could provide a valuable reference for green chemical separation processes and introduce a novel methodology and conceptual framework for glutamic acid.