IMPROVED SIMULATED MOVING-BED DEVICE AND METHOD FOR PARAXYLENE SEPARATION

摘要

The invention relates to a method for separating paraxylene with a purity at least equal to 99.5 wt.-% from an aromatic stream (F) in a single adsorption step in a simulated moving bed in an SMB device including: a zone (1) between the desorbent (D) supply point and the extract (E) extraction point; a zone (2) between the extract (E) extraction point and the stream (F) supply point; a zone (3) between the stream supply point and the raffinate (R) extraction point; and a zone (4) between the raffinate (R) extraction point and the desorbent (D) supply point, said method being performed according to a zone configuration (a, b, c, d) with a, b, c and d representing the number of adsorbent beds operating in zones 1, 2, 3 and 4 respectively. The invention comprises the use of: an SMB with 12 adsorbent beds operating with configuration 2, 5, 3, 2, an SMB with 15 adsorbent beds operating with configuration 3, 6, 4, 2, or an SMB with 19 adsorbent beds operating with configuration 4, 7, 6, 2, paradiethylbenzene being used as the desorbent in the latter case.