A transalkylation process co-feeds benzene at a relatively high proportion with C9+ aromatics in a feed stream to a transalkylation reactor. At lower proportions (≤5 wt %) of benzene, ring loss is greater for benzene than toluene and ring loss is increased by increasing the proportion of benzene in the feed stream. When the benzene is co-fed in a proportion sufficiently greater than 5 weight percent of the feed stream, ring loss is unexpectedly reduced.

A transalkylation process co-feeds benzene at a relatively high proportion with C9+ aromatics in a feed stream to a transalkylation reactor. At lower proportions (≤5 wt %) of benzene, ring loss is greater for benzene than toluene and ring loss is increased by increasing the proportion of benzene in the feed stream. When the benzene is co-fed in a proportion sufficiently greater than 5 weight percent of the feed stream, ring loss is unexpectedly reduced.

Systems and methods are provided for integration of an aromatic formation process for converting non-aromatic hydrocarbon to an aromatic product and subsequent methylating of a portion of the aromatic product to produce a methylated product, with improvements in the aromatic formation process and/or the methylation process based on integrating portions of the secondary processing trains associated with the aromatic formation process and the methylation process. The aromatic formation process and methylation process can be used, for example, for integrated production of specialty aromatics or gasoline blending components.

A method of making a xylene isomerization catalyst comprises the steps of (i) contacting a ZSM-5 zeolite starting material having a silica to alumina molar ratio of 20 to 50 and having a mesopore surface area in the range of 50 m.sup.2/gram to 200 m.sup.2/gram in a reactor with a base to provide an intermediate zeolite material; (ii) recovering the intermediate ZSM-5 zeolite material of step (i); (iii) contacting the intermediate zeolite material with an acid to provide an acid treated ZSM-5 zeolite product; (iv) recovering the acid treated ZSM-5 zeolite material; and (v) calcining the acid treated ZSM-5 zeolite material to provide a desilicated ZSM-5 zeolite product having a silica to alumina molar ratio of 20 to 150 and having a mesopore surface area in the range of 100 m.sup.2/gram to 400 m.sup.2/gram.

A method of making a xylene isomerization catalyst comprises the steps of (i) contacting a ZSM-5 zeolite starting material having a silica to alumina molar ratio of 20 to 50 and having a mesopore surface area in the range of 50 m.sup.2/gram to 200 m.sup.2/gram in a reactor with a base to provide an intermediate zeolite material; (ii) recovering the intermediate ZSM-5 zeolite material of step (i); (iii) contacting the intermediate zeolite material with an acid to provide an acid treated ZSM-5 zeolite product; (iv) recovering the acid treated ZSM-5 zeolite material; and (v) calcining the acid treated ZSM-5 zeolite material to provide a desilicated ZSM-5 zeolite product having a silica to alumina molar ratio of 20 to 150 and having a mesopore surface area in the range of 100 m.sup.2/gram to 400 m.sup.2/gram.

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 para-xylene and ethylbenzene from C.sub.8 aromatics containing ethylbenzene includes the steps of sending C.sub.8 aromatics containing ethylbenzene to an ethylbenzene liquid-phase adsorption separation device, wherein a suction liquid containing ethylbenzene and a suction residual liquid are obtained after the adsorption separation, and the desorbents in the suction liquid and the suction residual liquid are removed to obtain ethylbenzene and a suction residual oil; sending the suction residual oil to a para-xylene adsorption separation device, and unadsorbed components are discharged as a raffinate from the adsorbent bed; the adsorbent bed is rinsed with a desorbent to desorb the para-xylene therein and obtain an extract; the desorbents in the extract and the raffinate are respectively removed to obtain para-xylene and a raffinate oil; sending the raffinate oil to a xylene isomerization device to carry out xylene isomerization, and the isomerization product is fractionated.

The present disclosure relates to processes that catalytically convert a hydrocarbon feed stream predominantly comprising both isopentane and n-pentane to yield upgraded hydrocarbon products that are suitable for use either as a blend component of liquid transportation fuels or as an intermediate in the production of other value-added chemicals. The hydrocarbon feed stream is isomerized in a first reaction zone to convert at least a portion of the n-pentane to isopentane, followed by catalytic-activation of the isomerization effluent in a second reaction zone with an activation catalyst to produce an activation effluent. The process increases the conversion of the hydrocarbon feed stream to olefins and aromatics, while minimizing the production of C1-C4 light paraffins. Certain embodiments provide for further upgrading of at least a portion of the activation effluent by either oligomerization or alkylation.

The invention concerns a catalyst comprising at least one zeolite with structure type MTW, a matrix, at least one metal from group VIII of the periodic classification of the elements, said catalyst having a mesopore volume increased by at least 10% compared with its initial mesopore volume, which is generally in the range 0.55 to 0.75 mL/g, at the end of a treatment with steam at a partial pressure in the range 0.01 to 0.07 MPa and at a temperature in the range 300 C. to 400 C. for at least 0.5 hour. The invention concerns the process for the preparation of said catalyst as well as an isomerization process employing said catalyst.