Abstract: Disclosed herein is a process for producing para-xylene comprising the steps of: (a) contacting a feedstock comprising toluene with a first catalyst under effective vapor phase toluene disproportionation conditions to disproportionate said toluene and produce a first product comprising benzene, unreacted toluene and greater than equilibrium amounts of para-xylene; and (b) contacting a feedstock comprising C9+ aromatic hydrocarbons and benzene with a second catalyst in the presence of 0 wt. % or more of hydrogen having a 0 to 10 hydrogen/hydrocarbon molar ratio under effective C9+ transalkylation conditions to transalkylate said C9+ aromatic hydrocarbons and produce a second product comprising xylenes.

Abstract: A process for producing xylene from C9+ aromatic hydrocarbons comprises contacting a first feedstock comprising C9+ aromatic hydrocarbons with a first catalyst in the presence of 0 wt. % or more of hydrogen under effective vapor phase dealkylation conditions to dealkylate part of the C9+ aromatic hydrocarbons and produce a first product comprising benzene, toluene and residual C9+ aromatic hydrocarbons. A second feedstock comprising C9+ aromatic hydrocarbons and benzene and/or toluene is contacted with a second catalyst under effective liquid phase C9+ transalkylation conditions to transalkylate at least part of the C9+ aromatic hydrocarbons and produce a second product comprising xylenes.

Abstract: In a process for producing paraxylene, a hydrocarbon feedstock comprising benzene and/or toluene is contacted with an alkylating reagent comprising methanol and/or dimethyl ether in an alkylation reaction zone under alkylation conditions in the presence of an alkylation catalyst to produce an alkylated product comprising xylenes. The alkylation catalyst comprises a molecular sieve having a Constraint Index ?5, and the alkylation conditions comprise a temperature less than 500° C. At least part of the alkylated product is supplied to a paraxylene recovery unit to recover paraxylene and produce a paraxylene-depleted stream, which is then contacted with a xylene isomerization catalyst under conditions effective to isomerize xylenes in the paraxylene-depleted stream and produce an isomerized stream having a higher concentration of paraxylene than the paraxylene-depleted stream. At least part of the isomerized stream is then recycled to the paraxylene recovery unit to recover the paraxylene therein.

Abstract: Methods and related systems are disclosed for condensing a minor portion of an effluent stream from an alkylation reactor by contacting the effluent stream with a first liquid hydrocarbon quench stream and a second liquid hydrocarbon quench stream. The effluent stream includes catalyst fines from the reactor, and at least a portion of the catalyst fines are carried with the condensed minor portion of the effluent stream.

Abstract: A fluidized bed process for producing para-xylene via toluene and/or benzene methylation with methanol using a dual function catalyst system. A first catalyst accomplishes the toluene and/or benzene methylation and a second catalyst converts the by-products of the methylation reaction or unconverted methylating agent, improves the yields of the desired products, or a combination thereof. The inclusion of the second catalyst can suppress the C1-C5 non-aromatic fraction by over 50% and significantly enhance the formation of aromatics.

Abstract: A process for producing paraxylene by the catalytic alkylation of benzene and/or toluene with methanol. In prior art processes, water is typically co-injected with the methanol to improve the utilization of methanol, increase the amount of methanol that reacts with the benzene and/or toluene, and decrease the amount of methanol that decomposes to undesirable carbon monoxide, carbon dioxide, or water or reacts with itself to produce unwanted light olefinic gases. Rather than using purified methanol and co-feeding water as is taught in the prior art, crude, or unpurified, methanol that contains at least 5 wt %, such as between 5 and 35 wt %, water, based on the total amount of water and methanol feed, can be used as the alkylating agent, reducing the need to co-inject water at least partially, if not completely.

Abstract: A method of reducing the amount of carbon monoxide present during the metal reduction step of start-up, thus, maintaining metal dispersion and improving the metal reduction and catalyst yields. Carbon monoxide formation is minimized during the start-up procedure and during the initial catalyst dryout phase in a hydrogen-containing atmosphere, gas is purged from the reactor system, either continuously at constant pressure or by a series of pressure/depressure cycles, to remove carbon monoxide. The purging is conducted at temperatures of about 30-500° C. and pressures of about ?90-5,000 kPa(g) (?0.9-50 bar(g)). In this temperature range, carbon monoxide absorbed to the surface of the metal will desorb into the hydrogen-containing atmosphere and can be removed from the system along with carbon monoxide present in the atmosphere through the purging.

Abstract: A method of reducing the amount of carbon monoxide present during the metal reduction step of start-up, thus, maintaining metal dispersion and improving the metal reduction and catalyst yields. Carbon monoxide formation is minimized during the start-up procedure and during the initial catalyst dryout phase in a hydrogen-containing atmosphere, gas is purged from the reactor system, either continuously at constant pressure or by a series of pressure/depressure cycles, to remove carbon monoxide. The purging is conducted at temperatures of about 30-500° C. and pressures of about ?90-5,000 kPa(g) (?0.9-50 bar(g)). In this temperature range, carbon monoxide absorbed to the surface of the metal will desorb into the hydrogen-containing atmosphere and can be removed from the system along with carbon monoxide present in the atmosphere through the purging.

Abstract: The invention relates to a transalkylation system to convert feedstreams containing benzene and/or toluene (C7? aromatic hydrocarbons) and feedstreams containing C9+ aromatic hydrocarbons into a product stream comprising xylenes.

Abstract: The invention relates to treating a molecular sieve prepared by at least one in situ selectivation sequence wherein graphitic coke is adhered to said molecular sieve, which is useful in a toluene disproportionation process.

Abstract: The invention relates to a transalkylation system to convert feedstreams containing benzene and/or toluene (C7? aromatic hydrocarbons) and feedstreams containing C9+ aromatic hydrocarbons into a product stream comprising xylenes.