The present invention relates to a process and a device for separating a feedstock comprising benzene, toluene and C8+ compounds, by means of at least one reformate distillation column (C1), one aromatics extraction unit (P1), one para-xylene separation unit (P2), one xylene isomerization unit (P3) and one transalkylation unit (P4), the effluents of said units being separated in the following distillation columns: purification column (C6), deheptanizer (C7) and toluene column (C10), in which at least one of said distillation columns is suitable for being operated under vacuum so that: the majority of the C7 compounds are recovered in the product at the top of the distillation column operated under vacuum, and the majority of the C8+ compounds are recovered in the product at the bottom of the distillation column operated under vacuum.

Processes and apparatuses for producing a C.sub.8 aromatic isomer product are provided. The process comprises introducing a reformate stream comprising aromatic hydrocarbons to a reformate splitter column to provide a plurality of streams. One or more streams comprising at least one stream from the plurality of streams is passed to a reformate upgrading unit to obtain an upgraded reformate stream. The upgraded reformate stream is passed to an aromatics stripper column to provide an aromatics stripper sidedraw stream comprising C.sub.8 aromatic hydrocarbons. The aromatics stripper sidedraw stream is passed to a xylene separation unit to provide the C.sub.8 aromatic isomer product and a raffinate product stream. At least a portion of the raffinate product stream is processed in a liquid phase isomerization unit to obtain an isomerized stream.

Processes and apparatuses for producing a C.sub.8 aromatic isomer product are provided. The process comprises introducing a reformate stream comprising aromatic hydrocarbons to a reformate splitter column to provide a plurality of streams. One or more streams comprising at least one stream from the plurality of streams is passed to a reformate upgrading unit to obtain an upgraded reformate stream. The upgraded reformate stream is passed to an aromatics stripper column to provide an aromatics stripper sidedraw stream comprising C.sub.8 aromatic hydrocarbons. The aromatics stripper sidedraw stream is passed to a xylene separation unit to provide the C.sub.8 aromatic isomer product and a raffinate product stream. At least a portion of the raffinate product stream is processed in a liquid phase isomerization unit to obtain an isomerized stream.

The present invention relates to a method for converting a feed mixture comprising an aromatic C8 mixture of xylenes and ethylbenzene in which the para-xylene content of the xylene portion of the feed is less than equilibrium to produce a product mixture of reduced ethylbenzene content and a greater amount of para-xylene, which method comprises contacting the feed mixture at conversion conditions with a first catalyst having activity for the conversion of ethylbenzene, and with a second catalyst having activity for the isomerization of a xylene.

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.

Methods are provided for activation of catalysts comprising low amounts of a hydrogenation metal, such as low amounts of a Group 8-10 noble metal. The amount of hydrogenation metal on the catalyst can correspond to 0.5 wt % or less (with respect to the weight of the catalyst), or 0.1 wt % or less, or 0.05 wt % or less. Prior to loading a catalyst into a reactor, the corresponding catalyst precursor can be first activated in a hydrogen-containing atmosphere containing 1.0 vppm of CO or less. The thus first-activated catalyst can be transferred to a reactor with optional exposure to oxygen during the transfer, where it can be further activated using a hydrogen-containing atmosphere containing 3.0 vppm of CO or higher, to yield a twice-activated catalyst with high performance. The catalyst can be advantageously a transalkylation catalyst or an isomerization catalyst useful for converting aromatic hydrocarbons.

Methods are provided for activation of catalysts comprising low amounts of a hydrogenation metal, such as low amounts of a Group 8-10 noble metal. The amount of hydrogenation metal on the catalyst can correspond to 0.5 wt % or less (with respect to the weight of the catalyst), or 0.1 wt % or less, or 0.05 wt % or less. Prior to loading a catalyst into a reactor, the corresponding catalyst precursor can be first activated in a hydrogen-containing atmosphere containing 1.0 vppm of CO or less. The thus first-activated catalyst can be transferred to a reactor with optional exposure to oxygen during the transfer, where it can be further activated using a hydrogen-containing atmosphere containing 3.0 vppm of CO or higher, to yield a twice-activated catalyst with high performance. The catalyst can be advantageously a transalkylation catalyst or an isomerization catalyst useful for converting aromatic hydrocarbons.

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.