Patent ID: 7759534

Claim:
A process comprising separating paraxylene (PX) with a purity of at least 99.5% by weight from a feedstock F of aromatic hydrocarbons having essentially 8 carbon atoms by direct separation into a single stage of adsorption in a simulated moving bed in at least one column comprising a number of adsorbent beds separated by distribution/extraction plates P i , in which at least one feedstock F and one desorbent D are fed into the at least one column, and at least one extract E high in paraxylene and at least one raffinate R are drawn off, whereby the supply and draw-off points are changed over time with a switching time T providing a number of operating zones of the SMB column, including the following primary zones: zone 1 for desorption of the paraxylene located between the supply of the desorbent D and the draw-off of the extract E; zone 2 for desorption of the compounds of the raffinate, located between the draw-off of the extract E and the supply of the feedstock F; zone 3 for the adsorption of at least paraxylene, located between the supply of the feedstock and the draw-off of the raffinate R; zone 4 located between the draw-off of the raffinate R and the supply of the desorbent D, wherein the process is carried out conducted according to a configuration of zones (a, b, c, d) with: a=Number of adsorbent beds operating in zone 1; b=Number of adsorbent beds operating in zone 2; c=Number of adsorbent beds operating in zone 3; d=Number of adsorbent beds operating in zone 4; said process being conducted according to one of the following options: an SMB of 12 adsorbent beds operating according to configuration (2, 5, 3, 2), an SMB of 15 adsorbent beds operating according to configuration (3, 6, 4, 2), an SMB of 19 adsorbent beds operating according to configuration (4, 7, 6, 2), and, wherein the desorbent is paradiethylbenzene.