Disclosed is a process for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce two extract streams—one rich in paraxylene and a paraxylene-rich extract stream that is lean in ethylbenzene and an ethylbenzene-rich extract stream that is lean in paraxylene- and a paraxylene-depleted raffinate stream. A significant amount of the ethylbenzene is removed in the ethylbenzene-rich extract stream (at least enough to limit buildup in the isomerization loop), so the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy and capital intensive hydrogen recycle loop.

Disclosed herein are processes for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce a paraxylene-rich extract stream that also contains a significant amount of the ethylbenzene and a paraxylene-depleted raffinate stream. Because a significant amount of the ethylbenzene is removed in the paraxylene-rich extract stream (at least enough to limit buildup in the isomerization loop), the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy- and capital-intensive hydrogen recycle loop.

Disclosed herein are processes for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce a paraxylene-rich extract stream that also contains a significant amount of the ethylbenzene and a paraxylene-depleted raffinate stream. Because a significant amount of the ethylbenzene is removed in the paraxylene-rich extract stream (at least enough to limit buildup in the isomerization loop), the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy- and capital-intensive hydrogen recycle loop.

Disclosed herein are processes for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce a paraxylene-rich extract stream that also contains a significant amount of the ethylbenzene and a paraxylene-depleted raffinate stream. Because a significant amount of the ethylbenzene is removed in the paraxylene-rich extract stream (at least enough to limit buildup in the isomerization loop), the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy- and capital-intensive hydrogen recycle loop.

A process is described for separating paraxylene from a multicomponent fluid mixture of C8 aromatics. A mixture of C8 aromatics is fed to a simulated moving-bed adsorptive apparatus. The location of the feed to the apparatus is moved at set intervals. The rate of flow of feed to the apparatus is varied during each interval to enhance the separation of paraxylene from the multicomponent mixture.

A process is described for separating paraxylene from a multicomponent fluid mixture of C8 aromatics. A mixture of C8 aromatics is fed to a simulated moving-bed adsorptive apparatus. The location of the feed to the apparatus is moved at set intervals. The rate of flow of feed to the apparatus is varied during each interval to enhance the separation of paraxylene from the multicomponent mixture.

A process is described for separating paraxylene from a multicomponent fluid mixture of C8 aromatics. A mixture of C8 aromatics is fed to a simulated moving-bed adsorptive apparatus. The location of the feed to the apparatus is moved at set intervals. The rate of flow of feed to the apparatus is varied during each interval to enhance the separation of paraxylene from the multicomponent mixture.

Device and process for converting a feedstock of aromatic compounds, in which the feedstock is notably treated using a fractionation train (4-7), a xylenes separating unit (10) and an isomerization unit (11), and in which a pyrolysis unit (13) treats a second hydrocarbon-based feedstock, produces a pyrolysis effluent feeding the feedstock, and produces a pyrolysis gas comprising CO, CO2 and H2; a WGS water gas shift reaction section (50) suitable for treating the pyrolysis gas and for producing a WGS gas enriched in CO2 and in hydrogen; a CO2 aromatization reaction section (52) suitable for: at least partly treating the WGS gas to produce a hydrocarbon effluent comprising aromatic compounds, and feeding the feedstock with the hydrocarbon effluent.

Device and process for converting a feedstock of aromatic compounds, in which the feedstock is notably treated using a fractionation train (4-7), a xylenes separating unit (10) and an isomerization unit (11), and in which a pyrolysis unit (13) treats a second hydrocarbon-based feedstock, produces a pyrolysis effluent feeding the feedstock, and produces a pyrolysis gas comprising CO, CO2 and H2; a WGS water gas shift reaction section (50) suitable for treating the pyrolysis gas and for producing a WGS gas enriched in CO2 and in hydrogen; a CO2 aromatization reaction section (52) suitable for: at least partly treating the WGS gas to produce a hydrocarbon effluent comprising aromatic compounds, and feeding the feedstock with the hydrocarbon effluent.

The present invention concerns a zeolitic adsorbent agglomerate comprising at least one zeolite of faujasite type comprising barium and/or potassium, of porosity between 25% and 45%, and having a standard deviation σ of crystal size distribution in said agglomerate of less than 0.30 μm.

The invention also concerns the use of the zeolitic adsorbent agglomerate for the separation of hydrocarbon mixtures, and the process for separating hydrocarbon mixtures using said zeolitic adsorbent agglomerate.