MODELING AND OPTIMIZATION IN BED-LINE FLUSHING METHOD OF THE PARA-XYLENE SEPARATION SYSTEM

Abstract

Abstract: The saturated adsorption capacities and equilibrium constants of C₈ aromatic isomers were obtained by the static adsorption method. The breakthrough curves of C₈ aromatics isomer were plotted by dynamic adsorption experiments. The lumped mass transfer coefficients of C₈ aromatics were calculated through curve fitting by Aspen Chromatography. Based on the parameters above, the model of the industrial-scale simulated moving bed for para-xylene separation was constructed. The influences of dead volume, flushing flow rate and flushing liquid composition on the adsorption and separation performance of adsorbent were investigated. Especially, the optimization calculation of the bed-line flushing method was carried out and the preferable flushing set was figured out. The optimized the flushing method was calculated where the desorbent was used as the flushing stream between desorbent and extract ports, the extract stream was used between extract and feed ports, and the feed stream was used between feed and raffinate ports.

Key words: simulated moving bed, model, adsorption separation, xylene separation

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