Process and device for simulated moving bed separation with a reduced number of valves and lines

A device for separating at least one desired compound from a mixture comprising said compound, by simulated moving bed adsorption comprising:

• at least one column divided into a plurality of adsorbant beds Ai separated by distributor/extractor plates Pi for sequential supply and extraction of at least two supply fluids:
• a feed F and a desorbant D, and at least two withdrawn fluids:
• a raffinate Rand an extract E, Pi being disposed between the bed Ai and the immediately inferior bed Ai+1;
• the device also comprising networks of fluids, i.e. at least a feed network F-Net, a desorbant network D-Net, a raffinate network R-Net and an extract network E-Net, each of said networks being connected to the column via a plurality of lines comprising two-way controlled isolation valves, termed network valves, for sequential supply or withdrawal of said fluids;
• in which the column is divided, over at least the major portion of its height, into a plurality of superimposed adjacent sectors Sk, each sector Sk essentially being constituted by a column sector essentially comprising two successive beds of adsorbant and the two distributor/extractor plates Pi which are disposed immediately below said successive beds of adsorbant;
• each of the distributor/extractor plates Pi of each of the sectors Sk is a single common network for sequential supply and withdrawal of fluids F, D, R, E;
• the plates Pi of each sector Sk are connected together via an external bypass line Lk connected to each plate Pi of Sk via a connector (EMi) comprising a single two-way controlled isolation valve belonging to the plate Pi, termed the plate valve Vi, for sequential supply or withdrawal of fluids F, D, R, E from Pi;
• each of said bypass lines Sk comprises at least one controlled means for limiting the flow rate circulating in Lk, which is either installed on the line Lk or in a bypass around a plate valve Vi or a plate Pi of Sk;
• in which the bypass line Lk of each of the sectors Skis connected to each of the networks F-Net, D-Net, R-Net and E-Net via a single line comprising a single network valve, respectively VF, VD, VR, VE, for sequential supply or withdrawal of the corresponding fluid F, D, R, E to or from the sector Sk under consideration;
• said device comprising at least two superimposed adjacent sectors Sk and Sk+1, Sk comprising the plates Pi−1 and Pi connected via an external bypass line Lk connected to the column via two connectors respectively comprising the plate valves Vi−1 and Vi, and Sk+1 comprising the plates Pi+1 and Pi+2 connected via an external bypass line Lk+1 connected to the column via two connectors respectively comprising the plate valves Vi+1 and Vi+2, in which the two connectors of Sk on the column have between them an angular offset with respect to the axis of the column which is zero or 20° or less, the two connectors of Sk+1 on the column have between them an angular offset with respect to the axis of the column which is zero or 20° or less, and the connectors of Sk have with the connectors of Sk+1 a mean angular offset in the range 70° to 110°.