Two-Zone SMB/Chromatography for Center-Cut Separation from Ternary Mixtures: Linear Isotherm Systems

Abstract

A center-cut two-zone simulated moving bed (SMB)/chromatography system and a recycled cascade with two four-zone SMBs were designed to purify only the intermediate retained component in ternary mixtures. The operating conditions, productivity, and minimum ratio of total flow rate of desorbent to feed flow rate (Dtotal/F) were determined with the local equilibrium model, and purity and recovery were simulated by Aspen Chromatography. Compared to complete ternary separation, the separation constraints of the center-cut two-zone SMB/chromatography were less restrictive, and it showed higher purity of the intermediate retained component. For example, the purity was increased by 3.3% in the center-cut two-zone system for Dtotal/F = 4.0. Compared to complete ternary separation, the recycled cascade with two four-zone SMBs reduced the desorbent usage by recycling a dilute, unwanted product. For example, the minimum Dtotal/F value was decreased from 2.9 in the standard cascade to 1.0 in the recycled cascade. The ...