Enhanced performance of a three-zone simulated moving bed chromatography for separation of succinic acid and lactic acid by simultaneous use of port-location rearrangement and partial-feeding

• Performance of 3-zone SMB for organic acid separation was improved to a large extent.
• Port-location rearrangement (PR) and partial-feeding (PF) were used simultaneously.
• The combined use of PF and PR led to better performance than the use of either one.
• It was confirmed from both equilibrium-theory analysis and detailed simulation.
• The optimized 3-zone SMBs based on PF, PR, and PF–PR were compared systematically.

The performance of a three-zone simulated moving bed (SMB) chromatographic process for separation of succinic acid and lactic acid has been improved to a certain extent in previous researches by applying either a partial-feeding (PF) or a port-location rearrangement (PR) to its operation. To make a further improvement, the strategy of applying both PF and PR simultaneously to the three-zone SMB operation was proposed in this study. The results from both equilibrium-theory analysis and detailed simulation proved that the proposed strategy, which was called PF–PR in this article, had the benefit of a synergy between the individual merits of PF and PR in the three-zone SMB performance. As a consequence, the PF–PR mode could surpass the PF and the PR modes by a wide margin and the classical mode by a dramatic margin in the aspects of separation performance and throughput.