Experimental validation of the solvent-gradient simulated moving bed process for optimal separation of phenylalanine and tryptophan

► The solvent-gradient SMB for amino acid separation was validated experimentally. ► The amino acids separated were phenylalanine and tryptophan. ► Effect of modifier content on mass-transfer parameters was considered in the design. ► The SG-SMB experimental data were found to agree closely with the model predictions.