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

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• a feed F and a desorbant D, and at least two withdrawn fluids: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 R and 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 P-net, a desorbant network D-net, a raffinate network R-net and an extract network B-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 group of at least 2 and at most 5 successive beds of adsorbant and by 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 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 into or from Pi;
• each of said bypass lines Sk comprises at least one controlled means for limiting the flow rate in Lk, which is either installed on the line Lk or in a bypass around a plate valve Vi of a plate Pi of Sk;
• in which the bypass line Lk of each of the sectors Sk is 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 VFk, VDk, VRk, VEk, for sequential supply or withdrawal of the corresponding fluid F, D, R, E to or from the sector Sk under consideration;
• and in which each plate Pi of the sector Sk is uniquely connected to each of the networks F-net, D-net, R-net and B-net via, in series, the connector comprising the plate valve Vi then at least a portion of Lk then said single line comprising said single network valve, respectively VPk, VDk, VRk, VEk.