Abstract: The catalyst becomes at least partially deactivated by sorbing catalyst poisons present in the feed during a process for alkylating aromatics by contacting a feed containing benzene, toluene, xylenes, alkylbenzenes, naphthalene or substituted naphthalenes under liquid phase alkylating conditions with C2-C16 olefins in the presence of MCM-22, MCM-36, MCM-49, MCM-56, ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-48, ZSM-50, ZSM-4, ZSM-18, ZSM-20, Zeolite X, Zeolite Y, USY, mordenite or offretite to provide an alkylated aromatic product. The at least partially deactivated catalyst can be treated in situ by contacting with at least one polar compound having a dipole moment of at least 0.05 Debyes and selected from the group consisting of acetic acid, formic acid, water, and carbon monoxide, under conditions of temperature and pressure employed in the liquid phase alkylating conditions which are sufficient to at least partially desorb the catalyst poison from the catalyst.

Abstract: A process is described for removing polar compounds from an aromatic feedstock which contains polar compounds. The process comprises contacting the feedstock in an adsorption zone at a temperature of less than or equal to 130° C. with an adsorbent selective for the adsorption of said polar compounds and comprising a molecular sieve having surface cavities with cross-sectional dimensions greater than 5.6 Angstroms. A treated feedstock substantially free of said polar compounds can then be fed to an alkylation zone for contact under liquid phase alkylation conditions with an alkylating agent in the presence of an alkylation catalyst.

Abstract: A process for removing polar compounds from an aromatic feedstock containing polar compounds comprising the steps of:

Abstract: 1.

Abstract: A process for alkylating aromatics comprises: i) contacting a feed containing alkylatable aromatic, e.g., benzene, under liquid phase alkylating conditions with an alkylating agent, e.g., ethylene, in the presence of an alkylation catalyst comprising a porous crystalline material, e.g., MCM-22, to provide an alkylated aromatic product during which contacting said catalyst becomes at least partially deactivated by sorbing catalyst poisons present in said feed; ii) treating said at least partially deactivated catalyst in situ by contacting with at least one polar compound, e.g., water or acetic acid, having a dipole moment of at least 0.05 Debyes under conditions of temperature and pressure employed in said liquid phase alkylating conditions which are sufficient to at least partially desorb said catalyst poison from said catalyst; and iii) collecting said alkylated aromatic product.

Abstract: Akylation product is contacted with a purification medium in a liquid phase pre-reaction step to remove impurities and form a purified stream. The purified stream may then be further processed by liquid phase transalkylation to convert the polyalkylated aromatic compound to a monoalkylated aromatic compound. The process may use a large pore molecular sieve catalyst such as MCM-22 as the purification medium in the pre-reaction step because of its high reactivity for alkylation, strong retention of catalyst poisons and low reactivity for oligomerization under the pre-reactor conditions. Olefins, diolefins, styrene, oxygenated organic compounds, sulfur containing compounds, nitrogen containing compounds and oligomeric compounds are removed.

Abstract: A process is provided for producing pyridine and/or alkylpyridine compounds comprising reacting a feedstream of ammonia and at least one C.sub.1-5 carbonyl reactant under conversion conditions and in the presence of a phosphorus-modified molecular sieve containing catalyst to produce a product stream having a pyridine and/or a pyridine based compound selected from alkylpyridines or polyalkylpyridines. The catalyst has improved attrition resistance without affecting catalyst activity or selectivity.

Abstract: There is provided a high efficiency base synthesis process for shape selective production of pyridine and picoline products from ammonia and C.sub.1-5 carbonyl compounds. The process includes reacting ammonia and at least one C.sub.1-5 carbonyl reactant under suitable reaction conditions of temperature, pressure, and space velocity in the presence of a catalyst comprising a molecular sieve to produce a primary product comprising pyridine or picoline products and polyalkylpyridines or other higher molecular weight aromatic species, separating and collecting the pyridine or picoline products from the polyalkylpyridines or other higher molecular weight aromatic species, and circulating the polyalkylpyridines or other higher molecular weight aromatic species to the same or another catalyst under conversion conditions to yield additional pyridine or picoline products with substantially reduced amounts of polyalkylpyridines or other higher molecular weight aromatic species.

Abstract: There is provided a process for producing alkylaromatics, especially ethylbenzene and cumene, wherein a feedstock is first fed to a transalkylation zone and the entire effluent from the transalkylation zone is then cascaded directly into an alkylation zone along with an olefin alkylating agent, especially ethylene or propylene.

Abstract: A mixture of aromatic hydrocarbons, comprising ethylbenzene and at least one xylene, is isomerized using a two reactor system to convert the ethylbenzene to compounds that may be removed from the aromatic hydrocarbon stream and to produce a product stream wherein the para-xylene concentration is approximately equal to the equilibrium ratio of the para-isomer. The catalyst present in the first reactor is one that is effective for ethylbenzene conversion with minimal xylene loss when operated under suitable conversion conditions, e.g., a catalyst comprising silica bound ZSM-5 that has been selectivated by one or more silicon impregnations or that has been coke selectivated. The catalyst present in the second reactor is one which is effective to catalyze xylene isomerization when operated under suitable conditions. Each of the catalysts of this invention may contain one or more hydrogenation or dehydrogenation components.

Abstract: A mixture of aromatic hydrocarbons, comprising ethylbenzene and at least one xylene, is treated to convert the ethylbenzene to compounds that may be removed from the aromatic hydrocarbon stream and to isomerize any xylenes present. The ethylbenzene conversion catalyst is one that is effective for ethylbenzene conversion with minimal xylene loss, e.g., a silica bound intermediate pore size zeolite that has been selectivated. The xylene isomerization catalyst is one which is effective to catalyze xylene isomerization. Each of the catalysts of this invention may contain one or more hydrogenation or dehydrogenation components.

Abstract: There is provided a process for preparing ethylbenzene using liquid phase alkylation and vapor phase transalkylation. The liquid phase alkylation reaction may be catalyzed by an acidic solid oxide, such as MCM-22, MCM-49 and MCM-56. The vapor phase transalkylation may be catalyzed by a medium-pore size zeolite such as ZSM-5. The process may be run continuously with the continuous introduction of fresh benzene feed containing at least 500 ppm of nonbenzene hydrocarbon impurities. The combined ethylbenzene product of these alkylation and transalkylation reactions has very low levels of impurities including xylene, hydrocarbons having 7 or less carbon atoms and hydrocarbons having 9 or more carbon atoms.

Abstract: A process is provided for catalytic conversion of feedstock comprising aromatic compounds to product comprising aromatic compounds which differs from said feedstock. The catalyst required in the process comprises a crystalline material having the structure of MCM-58. Said crystalline material may have been treated with one or more monomeric or polymeric siloxane compounds which decompose to oxide or non-oxide ceramic or solid-state carbon species.

Abstract: A mixture of aromatic hydrocarbons, comprising ethylbenzene and at least one xylene, is isomerized using a two component catalyst system to convert the ethylbenzene to compounds that may be removed from the aromatic hydrocarbon stream and to produce a product stream wherein the para-xylene concentration is approximately equal to the equilibrium ratio of the para-isomer. The first catalyst comprises an intermediate pore size zeolite that is effective for ethylbenzene conversion. The first catalyst is preferably silica-bound. The second catalyst comprises an intermediate pore size zeolite, which further has a small crystal size and which is effective to catalyze xylene isomerization. Each of the catalysts of this invention may contain one or more hydrogenation/dehydrogenation component.

Abstract: A process for shape selective hydrocarbon conversion that involves contacting a hydrocarbon feedsteam, including ethylbenzene, under conversion conditions with a catalytic molecular sieve which has been modified by being ex situ selectivated with a silicon compound. The ex situ selectivation involves exposing the molecular sieve to at least two silicon impregnation sequences, each sequence comprising an impregnation with a silicon compound followed by calcination. The modified catalyst used in the process may also be steamed. Optionally, the modified catalyst may be trim-selectivated.

Abstract: A process for shape selective hydrocarbon conversion that involves contacting a hydrocarbon feedsteam, including ethylbenzene, under conversion conditions with a catalytic molecular sieve which has been modified by being ex situ selectivated with a silicon compound. The ex situ selectivation involves exposing the molecular sieve to at least two silicon impregnation sequences, each sequence comprising an impregnation with a silicon compound followed by calcination. The modified catalyst used in the process may also be steamed. Optionally, the modified catalyst may be trim-selectivated.