Abstract: Process for separating xylenes starting from a feed comprising cuts of isomers of aromatic hydrocarbons containing 8 carbon atoms, in a simulated moving bed, by selective adsorption of a xylene isomer in the presence of a desorbent, by means of particles of agglomerated zeolitic adsorbent based on zeolite crystals with a number-average diameter less than or equal to 1.2 ?m, wherein the number-average diameter of said particles of adsorbent is between 150 ?m and 500 ?m and the mechanical strength measured by the Shell method series SMS1471-74 adapted for agglomerates with a size below 500 ?m is greater than or equal to 2 MPa.

Abstract: The present invention describes a process for separating xylenes in simulated counter-current (simulated moving bed, SMB) for the treatment of feeds including oxygen-containing aromatic impurities of the phenol type and/or derivatives thereof, by controlled injection of water in the ingoing streams.

Abstract: Provided is a zeolite-based adsorbent in the form of agglomerates, where the adsorbent having a tortuosity factor, calculated from the pore distribution determined by mercury intrusion porosimetry, of greater than 1 and less than 3. The adsorbent also has a porosity as determined by mercury intrusion porosimetry of between 25% and 35%. The adsorbent is useful in the field of separations in particular in a process for separating para-xylene from aromatic hydrocarbon isomer fractions containing 8 carbon atoms.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes which can be used for the treatment of paraxylene-rich feeds (more than 25% by weight of paraxylene), in which the operating conditions are optimized by means of a specific relationship between the cycle time and the desorbant flow rate.

Abstract: A method for measuring the concentrations of species present at at least one point of a separation unit operating in simulated moving bed (SMB) mode, or a hybrid separation unit employing a step for simulated moving bed (SMB) separation and a step for crystallization, by calibration by inline acquisition of Raman spectra for different mixtures; analysis by inline signal processing of the Raman spectrum.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes, in which the operating conditions are optimized by means of a specific relationship between the cycle time and the flow rate of the desorbant.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes which can be used for the treatment of paraxylene-rich feeds (more than 25% by weight of paraxylene), in which the operating conditions are optimized by means of a specific relationship between the cycle time and the desorbant flow rate.

Abstract: The invention relates to a method for separating meta-xylene from C8 aromatic fractions, using a zeolitic adsorbent based on sodium-exchanged or sodium-and-lithium-exchanged agglomerated crystals of zeolite Y, with a large external surface area.

Abstract: The invention relates to an adsorbent comprising a zeolite-based phase and a non-zeolite-based phase, said adsorbent having: an outer surface area of less than or equal to 30 m2·g?1, preferably less than or equal to 20 m2·g?1, a zeolite-based phase comprising at least one zeolite of FAU structure of X type, and a pore diameter distribution, determined by mercury intrusion according to standard ASTM D 4284-83 and expressed by the volume distribution dV/dlogDHg, in which DHg is the apparent pore diameter and V is the pore volume, the mode of which is between 100 nm and 250 nm, limits inclusive. The invention also relates to a process for preparing the said adsorbent and to the uses thereof, especially for separating xylene isomers.

Abstract: The present invention describes a process for the simulated moving bed separation of xylenes, in which the operating conditions are optimized by means of a specific relationship between the cycle time and the flow rate of the desorbant.

Abstract: The present invention relates to zeolite adsorbents based on agglomerated zeolite X crystals comprising barium, potassium and sodium. These adsorbents find applications in the separation of aromatic C8 isomer fractions and especially xylene.

Abstract: The present invention relates to zeolite adsorbents based on agglomerated zeolite X crystals comprising barium, potassium and sodium. These adsorbents find applications in the separation of aromatic C8 isomer fractions and especially xylene.

Abstract: A method for measuring the concentrations of species present at at least one point of a separation unit operating in simulated moving bed (SMB) mode, or a hybrid separation unit employing a step for simulated moving bed (SMB) separation and a step for crystallization, by calibration by inline acquisition of Raman spectra for different mixtures; analysis by inline signal processing of the Raman spectrum.

Abstract: The present invention relates to zeolitic adsorbents based on agglomerated crystals of FAU zeolite containing barium and/or potassium, with large external surface area, combining optimum properties in terms of selectivity and mechanical strength. These adsorbents find applications in the separation of cuts of C8-aromatic isomers and notably of xylenes, in the separation of isomers of substituted toluene such as nitrotoluene, diethyltoluene, toluenediamine, in the separation of cresols, and in the separation of polyhydric alcohols such as sugars.

Abstract: The present invention relates to a zeolite-based adsorbent comprising at least one zeolite of FAU structure of LSX type and comprising barium and/or potassium, in which the outer surface area of said zeolite-based adsorbent, measured by nitrogen adsorption, is between 20 m2·g?1 and 100 m2·g?1, limits inclusive. The present invention also relates to the use of such a zeolite-based adsorbent as an adsorption agent, and also to the process for separating para-xylene from aromatic isomer fractions containing 8 carbon atoms.

Abstract: The present invention relates to zeolitic adsorbents based on agglomerated crystals of FAU zeolite comprising barium and/or potassium, with large external surface area, combining optimum properties in terms of selectivity and mechanical strength. These adsorbents find applications in the separation of cuts of C8-aromatic isomers and notably of xylenes, in the separation of isomers of substituted toluene such as nitrotoluene, diethyltoluene, toluenediamine, in the separation of cresols, and polyhydric alcohols, such as sugars.

Abstract: The invention relates to an adsorbent comprising a zeolite-based phase and a non-zeolite-based phase, said adsorbent having: an outer surface area of less than or equal to 30 m2·g?1, preferably less than or equal to 20 m2·g?1, a zeolite-based phase comprising at least one zeolite of FAU structure of X type, and a pore diameter distribution, determined by mercury intrusion according to standard ASTM D 4284-83 and expressed by the volume distribution dV/d log DHg, in which DHg is the apparent pore diameter and V is the pore volume, the mode of which is between 100 nm and 250 nm, limits inclusive. The invention also relates to a process for preparing the said adsorbent and to the uses thereof, especially for separating xylene isomers.

Abstract: The present invention relates to a zeolite-based adsorbent comprising at least one zeolite of FAU structure of LSX type and comprising barium and/or potassium, in which the outer surface area of said zeolite-based adsorbent, measured by nitrogen adsorption, is between 20 m2·g?1 and 100 m2·g?1, limits inclusive. The present invention also relates to the use of such a zeolite-based adsorbent as an adsorption agent, and also to the process for separating para-xylene from aromatic isomer fractions containing 8 carbon atoms.

Abstract: The present invention relates to a zeolite absorbent comprising at least one FAU zeolite with hierarchical porosity and comprising barium or barium and potassium, and the external surface area of which is greater than 20 m2·g?1, and the non-zeolite phase content being between 6% and 12% by weight with respect to the total weight of the absorbent. The present invention also relates to the use of such a zeolite absorbent as an adsorption agent, as well as the method for separation of para-xylene from aromatic isomer fractions with 8 carbon atoms.

Abstract: The invention relates to a method for separating meta-xylene from C8 aromatic fractions, using a zeolitic adsorbent based on sodium-exchanged or sodium-and-lithium-exchanged agglomerated crystals of zeolite Y, with a large external surface area.