A method of producing p-xylene, the method comprising the steps of converting the C9+ aromatic hydrocarbons and the hydrogen gas in the presence of a dealkylation catalyst to produce a dealkylation effluent, separating the dealkylation effluent to produce a carbon-nine (C9) aromatics stream, a xylene stream, and a toluene stream, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent, reacting the C9 aromatics stream and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the C6 to C9+ aromatic hydrocarbons in the isomerization effluent and the transalkylation effluent in the splitter column to produce a benzene recycle, a toluene recycle, a xylene recycle and a C9+ recycle.

A method of producing p-xylene, the method comprising the steps of converting the C9+ aromatic hydrocarbons and the hydrogen gas in the presence of a dealkylation catalyst to produce a dealkylation effluent, separating the dealkylation effluent to produce a carbon-nine (C9) aromatics stream, a xylene stream, and a toluene stream, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent, reacting the C9 aromatics stream and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the C6 to C9+ aromatic hydrocarbons in the isomerization effluent and the transalkylation effluent in the splitter column to produce a benzene recycle, a toluene recycle, a xylene recycle and a C9+ recycle.

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 2.5, a stage B of fractionation by distillation in a 2-cut distillation column of the fractions A21 and A22 resulting from stage A, in which said fractions are introduced separately at distinct injection points, and makes it possible to obtain a fraction B2 containing ethylbenzene, ortho-xylene and meta-xylene, and a fraction B42 devoid of aromatic compounds having 8 carbon atoms and containing desorbent.

A method for producing para-xylene (PX) includes introducing a C.sub.8 aromatic-containing composition to a xylene rerun column to separate the C.sub.8 aromatic-containing composition into a xylene-containing effluent and a heavy effluent and passing the xylene-containing effluent to a PX processing loop that includes a PX recovery unit operable to separate a PX product from the xylene-containing effluent, a membrane isomerization unit operable to convert a portion of the MX, OX, or both from the xylene-containing effluent to PX, an EB dealkylation unit operable to dealkylate EB from the xylene-containing effluent to produce benzene, toluene, and other C.sub.7− compounds, and a membrane separation unit operable to produce a permeate that is PX-rich and a retentate that is PX-lean. The permeate is passed to the PX recovery unit for recovery of PX, which the retentate is bypassed around the PX recovery unit circulated through the xylene processing loop.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.

A process for producing benzene and xylenes comprising introducing hydrocarbon liquid stream to hydroprocessor to yield first gas stream and hydrocarbon product (C.sub.5+); optionally introducing hydrocarbon product to first aromatics separating unit to produce saturated hydrocarbons (C.sub.5+) and first aromatics stream (C.sub.6+); feeding hydrocarbon product and/or saturated hydrocarbons to reformer to produce reformer product, second gas stream, and hydrogen stream; introducing reformer product to second aromatics separating unit to produce a non-aromatics recycle stream and second aromatics stream comprising C.sub.6+ aromatics; recycling non-aromatics recycle stream to reformer; introducing first aromatics stream and/or second aromatics stream to third aromatics separating unit to produce first C.sub.6 aromatics (benzene), C.sub.7 aromatics (toluene), C.sub.8 aromatics (xylenes&ethylbenzene), C.sub.9 aromatics, C.sub.10 aromatics, and C.sub.11+ aromatics; introducing C.sub.7 aromatics, C.sub.9 aromatics, C.sub.10 aromatics, or combinations thereof to disproportionation and transalkylation unit to yield third aromatics stream (benzene and xylenes); and conveying C.sub.11+ aromatics to hydroprocessor.

Para-xylene production processes are disclosed, with such processes being integrated with extractive distillation or other separation to effectively separate, for example to remove and recover, ethylbenzene and other components that co-boil with the isomers of xylene. This allows for xylene isomerization, downstream of the separation of para-xylene from its other isomers, to be operated under milder conditions (e.g., liquid phase, absence of added hydrogen) without the need for ethylbenzene conversion. The associated decreased yields of byproducts such as light gases and non-aromatic hydrocarbons, together with the generation of purified ethylbenzene having value for styrene monomer production, can significantly improve overall process economics.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.