Abstract: The present invention describes a process for obtaining para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, said process comprising a single stage A of separation in a simulated moving bed carried out with a zeolite as adsorbent and a desorbent and making it possible to obtain at least three fractions, a fraction A1 comprising a mixture of para-xylene and of desorbent and two fractions A21, A22 comprising ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent, said stage is carried out at a temperature between 20° C. and 250° C., under a pressure between the bubble pressure of the xylenes at the operating temperature and 2.0 MPa, and with a ratio by volume of the desorbent to the feedstock in the unit for separation 2 in a simulated moving bed is between 0.4 and 2.

Abstract: Method for the simulated moving bed (SMB) separation of a feedstock (F), in which: at least one zone (1, 2, 3, 4) contains fewer than three beds, if the stream (D, E, F, R) delimiting said zone and situated upstream of said zone is injected or withdrawn at the plate Pi via the bypass line Li/i+1, then the stream delimiting said zone and situated downstream of said zone is injected/withdrawn at the plate Pj via the bypass line Lj/j+1, and if the stream delimiting said zone and situated downstream of said zone is injected or withdrawn at the plate Pi via the bypass line Li?1/i, then the stream delimiting said zone and situated upstream of said zone is injected/withdrawn at the plate Pj via the bypass line Lj?1/j.

Abstract: The present invention describes a process for obtaining para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, said process comprising a single stage A of separation in a simulated moving bed carried out with a zeolite as adsorbent and a desorbent and making it possible to obtain at least three fractions, a fraction A1 comprising a mixture of para-xylene and of desorbent and two fractions A21, A22 comprising ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent, said stage is carried out at a temperature between 20° C. and 250° C., under a pressure between the bubble pressure of the xylenes at the operating temperature and 2.0 MPa, and with a ratio by volume of the desorbent to the feedstock in the unit for separation 2 in a simulated moving bed is between 0.4 and 2.

Abstract: Method for the simulated moving bed separation of a feedstock (F), in which when a fluid/effluent (feedstock F, desorbent D, extract E, raffinate R) is injected/withdrawn into/from a chosen plate (Pi) using an external bypass line (Li?1/i, Li/i+1) connected to said chosen plate (Pi), the flow rate within the said external bypass line (Li?1/i, Li/i+1) is controlled in such a way that: a major proportion of the fluid/effluent (F, D, E, R) is injected/withdrawn into/from the chosen plate (Pi); and a minor proportion of the fluid/effluent (F, D, E, R) is injected/withdrawn into/from the adjacent plate (Pi?1, Pi+1) connected to the said external bypass line (Li?1/i, Li/i+1).

Abstract: Method for the simulated moving bed separation of a feedstock (F), in which when a fluid/effluent (feedstock F, desorbent D, extract E, raffinate R) is injected/withdrawn into/from a chosen plate (Pi) using an external bypass line (Li?1/i, Li+1/i) connected to said chosen plate (Pi), the flow rate within the said external bypass line (Li?1/i, Li+1/i) is controlled in such a way that: a major proportion of the fluid/effluent (F, D, E, R) is injected/withdrawn into/from the chosen plate (Pi); and a minor proportion of the fluid/effluent (F, D, E, R) is injected/withdrawn into/from the adjacent plate (Pi?1, Pi+1) connected to the said external bypass line (Li?1/i, Li+1/i).

Abstract: Method for the simulated moving bed (SMB) separation of a feedstock (F), in which: at least one zone (1, 2, 3, 4) contains fewer than three beds, if the stream (D, E, F, R) delimiting said zone and situated upstream of said zone is injected or withdrawn at the plate Pi via the bypass line Li/i+1, then the stream delimiting said zone and situated downstream of said zone is injected/withdrawn at the plate Pj via the bypass line Lj/j+1, and if the stream delimiting said zone and situated downstream of said zone is injected or withdrawn at the plate Pi via the bypass line Li?1/i, then the stream delimiting said zone and situated upstream of said zone is injected/withdrawn at the plate Pj via the bypass line Lj?1/j.

Abstract: The present invention describes a novel configuration for simulated moving bed separation processes characterized by using two adsorbers each containing 12 beds, these two adsorbers functioning in parallel. This novel configuration can be used to optimize para-xylene production.

Abstract: The present invention describes an analysis device and a method associated with this device, said device comprising an analysis cell (8) containing an optrode (10), receiving an input laser signal and sending an output signal to the Raman spectrometer, and said method using two analysis routes: an analysis route 1 connected to the internal circulation current passing from adsorber B to adsorber A, and an analysis route 2 connected to the distilled raffinate originating from distillation column C.

Abstract: The present invention describes a device for the distribution of fluids in a multi-stage column operating in simulated moving bed (SMB) mode comprising, in the direction of flow of the principal fluid, a distribution system (6) for auxiliary fluids, and a distributor plate (10) supported by stiffening elements (7) located below said plate (10), said device being interposed between two successive beds of granular solid (2) denoted the upstream and downstream bed, the distribution system and the stiffening elements being immersed in the upstream and downstream granular beds to a slight extent with an upper limit for the degree of immersion.

Abstract: The present invention describes an analysis device and a method associated with this device, said device comprising an analysis cell (8) containing an optrode (10), receiving an input laser signal and sending an output signal to the Raman spectrometer, and said method using two analysis routes: an analysis route 1 connected to the internal circulation current passing from adsorber B to adsorber A, and an analysis route 2 connected to the distilled raffinate originating from distillation column C.

Abstract: A device (SMB) for separation by simulated moving bed adsorption comprises a plurality of elementary zones Zi in series operating in a closed loop, each of said zones comprising, between two successive fluid injection or extraction points, a unique bed Li of adsorbant solid with volume VAi and a non-selective free volume Vi, in which the majority of the zones are ordinary elementary zones each having an identical volume VA of the same adsorbant S, and a substantially identical non-selective free volume equal to V; the device also comprises at least one particular elementary zone Z0, termed the particular elementary zone, comprising a non-selective free volume V0 which is greater than V, and a unique bed L0 of adsorbant S0 with volume VA0 which is less than VA, S0 having a volume adsorption capacity C0 which is greater than that, C, of S, such that the overall adsorption capacity C0×VA0 of Z0 is closer to the overall adsorption capacity C×VA of each of the ordinary elementary zones than the overall adsorption

Abstract: A device (SMB) for separation by simulated moving bed adsorption comprises a plurality of elementary adsorption zones Zi in series operating in a closed loop, and at least one singular adsorption zone with a dead volume which is greater than the adsorption zones Zi, the solid adsorbant of said singular adsorption zone having a granulometry which is lower than that of the solid adsorbant of the ordinary adsorption zones.

Abstract: A process for the production of para-xylene by simulated counter-current adsorption with high flexibility with respect to a reference run (100%) uses 2 adsorbers each with 12 beds, said adsorbers being able to be connected in accordance with 3 different modes; the flexibility obtained is 50% to 150%.

Abstract: Device for stiffening the plates of a multi-stage column with a diameter of more than 2 meters, whereby each plate supports a particle bed and the flow of at least one fluid passes through it from top to bottom, whereby said device consists of a number of beams that are located under the plate in question, each beam having a lower surface that is shaped like a triangle.

Abstract: A process for the production of para-xylene by simulated counter-current adsorption with high flexibility with respect to a reference run (100%) uses 2 adsorbers each with 12 beds, said adsorbers being able to be connected in accordance with 3 different modes; the flexibility obtained is 50% to 150%.

Abstract: The present invention describes a novel configuration for simulated moving bed separation processes characterized by using two adsorbers each containing 12 beds, these two adsorbers functioning in parallel. This novel configuration can be used to optimize para-xylene production.

Abstract: The present invention describes a method for measuring the concentrations of species present at one point of a separation unit functioning in simulated moving bed mode (SMB), using an immersing probe located at one point in the unit or on one of the streams entering or leaving said unit, and a thermocouple located in the vicinity of the immersing probe, in which a Raman spectrum obtained using a laser source functioning at a wavelength of 785 nm is utilized.

Abstract: A process for separating a feed F by simulated moving bed adsorption in a SMB device comprises external bypass lines Li/i+1 which directly connect two successive plates, Pi, Pi+1, the index “i” being either even or (exclusive of the foregoing) odd, along the whole length of the column, allowing said plates to be flushed, in which each of the bypass lines Li/i+1 comprises automated means for regulating the flow rate in the bypass lines, the bypass lines in certain cases being subject to a flushing flow during injection or withdrawal operations.

Abstract: A process for separating a feed F by simulated moving bed adsorption in a SMB device is described, the device comprising external bypass lines Li/i+1 which directly connect two successive plates Pi, Pi+1, the index i being either even or (exclusive of the foregoing) odd, along the whole length of the column, in order to flush said plates, in which each of the bypass lines Li/i+1 comprises automated means for regulating the flow rate in the bypass lines, the degree of opening of said regulating means being defined by the following three rules: a) establishing a flow rate corresponding to an oversynchronicity in the range 15% to 30% in all of the open bypass lines of zone 1; b) establishing a flow rate corresponding to the synchronicity to within plus or minus 8% in all of the open bypass lines of zones 2 and 3; c) establishing a flow rate corresponding to an oversynchronicity in the range 20% to 40% in all of the open bypass lines of zone 4.

Abstract: A process for separating a feed F by simulated moving bed adsorption in a SMB device comprises at least one zone 1 for desorption of the compounds produced in the extract, a zone 2 for desorption of the compounds produced in the raffinate, a zone 3 for adsorption of the compounds produced in the extract, a zone 4 located between the raffinate withdrawal and the desorbant supply, the device comprising external by-pass lines Li/i+1 directly connecting two successive plates Pi and Pi+1; in which the degree of opening of means for restricting the flushing flow rate of the by-pass lines Li/i+1 are sequentially modified such that: 1) in an operational zone where there is at least one closed by-pass line, a super-synchronicity of the flushing flow rate is established in all of the by-pass lines which are not closed belonging to the zone under consideration, said super-synchronicity being defined by the following formula: S=a+b(nf/nt) in which the constant a is a constant in the range ?5 to 5 and b is a constant