Abstract: There is provided a method for preparing para-divinylbenzene by dehydrogenating para-diethylbenzene followed by crystallizing para-divinylbenzene. The para-diethylbenzene may be prepared by alkylating ethylbenzene with ethylene in the presence of a para-selective molecular sieve catalyst, such as ZSM-5 modified with an oxide of magnesium and, optionally, an oxide of phosphorus.

Abstract: There is provided a mixed catalyst of ZSM-5 and ZSM-12. Alkylbenzenes, especially heavy aromatic bottoms from cumene production, may be cracked over this mixed catalyst.

Abstract: There is provided a process for converting propane to ethylene over a zeolite catalyst comprising ZSM-23. This zeolite may be contacted with an anhydrous acidic oxide gas capable of accepting hydrogen by reacting therewith, such as sulfur dioxide (SO.sub.2), in order to enhance the ethylene selectivity of the conversion. The zeolite may either be pretreated with this acidic oxide gas or contacted in situ by cofeeding the acidic oxide gas along with the propane reactant. Particularly in view of the tendency of zeolites such as ZSM-5 to further convert olefins produced into aromatics and other hydrocarbons, the large degree of ethylene selectivity achieved by the process of the present invention is surprising.

Abstract: There is provided a process for converting propane to ethylene over a zeolite catalyst comprising ZSM-50. This zeolite may be contacted with an anhydrous acidic oxide gas capable of accepting hydrogen by reacting therewith, such as sulfur dioxide (SO.sub.2), in order to enhance the ethylene selectivity of the conversion. The zeolite may either be pretreated with this acidic oxide gas or contacted in situ by cofeeding the acidic oxide gas along with the propane reactant. Particularly in view of the tendency of zeolites such as ZSM-5 to further convert olefins produced into aromatics and other hydrocarbons, the large degree of ethylene selectivity achieved by the process of the present invention is surprising.

Abstract: Methanol is catalytically converted to hydrocarbons with high yield of light olefins. The catalysts employed are crystalline aluminosilicate zeolites having high silica to alumina ratios and the conversion is conducted at temperatures of from about 350.degree. C. to 600.degree. C. and at pressures ranging between about 1 atmospheres to about 100 atmospheres.

Abstract: There is provided a mixed catalyst of ZSM-5 and ZSM-12. Alkylbenzenes, especially heavy aromatic bottoms from cumene production, may be cracked over this mixed catalyst.

Abstract: A process for the production of 3,4-dimethyl-1-ethylbenzene by selective alkylation of dimethylbenzene with ethylene. The process is carried out in the presence of a crystalline zeolite catalyst having a silica to alumina mole ratio of at least about 12 and a Constraint Index of greater than 2 and up to about 12.

Abstract: A process is provided for modifying ZSM-5 type zeolite catalysts with halogen-based treating agents in order to enhance the para-selective properties of such catalysts for the conversion of aromatic materials to dialkyl-substituted benzene compounds. Halogen-based treating agents include HCl, HBr, Cl.sub.2, CCl.sub.4, GeCl.sub.4 and mixtures thereof. Catalyst compositions so treated can be used in alkylation, transalkylation or disproportionation processes to provide product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: There is provided a mixed catalyst of ZSM-5 and ZSM-12. Alkylbenzenes, especially heavy aromatic bottoms from cumene production, may be cracked over this mixed catalyst.

Abstract: A method is provided for treating modified ZSM-5 type zeolite catalysts with a vapor phase organophosphorus reagent such as trimethylphosphite or dimethylmethylphosphonate in order to improve the para-selective properties of such catalysts for the conversion of aromatic materials. The modified zeolites so treated are those which contain a minor proportion of a difficultly reducible oxide such as magnesium oxide, calcium oxide and/or phosphorus oxide. Such catalyst compositions can be used in alkylation, transalkylation or disproportionation processes to provide alkylated aromatic product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A method is provided for treating modified ZSM-5 type zeolite catalysts with a vapor phase organophosphorus reagent such as trimethylphosphite or dimethylmethylphosphonate in order to improve the para-selective properties of such catalysts for the conversion of aromatic materials. The modified zeolites so treated are those which contain a minor proportion of a difficultly reducible oxide such as magnesium oxide, calcium oxide and/or phosphorus oxide. Such catalyst compositions can be used in alkylation, transalkylation or disproportionation processes to provide alkylated aromatic product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A process for alkylation of aromatic hydrocarbon reactants to dialkylbenzene products, whereby chemically modified zeolite catalysts are treated with an organic acid to enhance their intrinsic para-selectivity in the alkylation reaction. The modified zeolites which may be so reselectivated or improved comprise those crystalline zeolites having a constraint index of 1 to 12, a silica to alumina mole ratio of at least 12, and having a minor proportion of the oxide form of one or more chemical elements (e.g. phosphorus and magnesium) deposited thereon.

Abstract: A process is provided for modifying ZSM-5 type zeolite catalysts with sulfur-based treating agents in order to enhance the para-selective properties of such catalysts for the conversion of aromatic materials to dialkyl-substituted benzene compounds. Sulfur-based treating agents include hydrogen sulfide and sulfur dioxide. Catalyst compositions so treated can be used in alkylation, transalkylation or disproportionation processes to provide product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A process is provided for modifying ZSM-5 type zeolite catalysts with gaseous nitrogen-based treating agents in order to enhance the para-selective properties of such catalysts for the conversion of aromatic materials to dialkyl-substituted benzene compounds. Nitrogen-based treating agents include nitrogen dioxide and ammonia. Catalyst compositions so treated can be used in alkylation, transalkylation or disproportionation processes to provide product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A process is provided for modifying ZSM-5 type zeolite catalysts with carbon dioxide treating agent in order to enhance the para-selective properties of such catalysts for the conversion of aromatic materials to dialkyl-substituted benzene compounds. Catalyst compositions so treated can be used in alkylation, transalkylation or disproportionation processes to provide product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A method is provided for treating modified ZSM-5 type zeolite catalysts with a vapor phase organophosphorus reagent such as trimethylphosphite or dimethylmethylphosphonate in order to improve the para-selective properties of such catalysts for the conversion of aromatic materials. The modified zeolites so treated are those which contain a minor proportion of a difficultly reducible oxide such as magnesium oxide, calcium oxide and/or phosphorus oxide. Such catalyst compositions can be used in alkylation, transalkylation or disproportionation processes to provide alkylated aromatic product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A method is provided for treating modified ZSM-5 type zeolite catalysts with a vapor phase organophosphorus reagent such as trimethylphosphite in order to improve the para-selective properties of such catalysts for the conversion of aromatic materials. The modified zeolites so treated are those which contain a minor proportion of a difficultly reducible oxide such as magnesium oxide, calcium oxide and/or phosphorus oxide. Such catalyst compositions can be used in alkylation, transalkylation or disproportionation processes to provide alkylated aromatic product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.

Abstract: A modified zeolite composition useful for the conversion of aromatic compounds to dialkylbenzene compounds rich in the 1,4-dialkylbenzene isomer. The reaction is carried out in the presence of zeolite catalyst having a silica to alumina mole ratio of at least 12 and a constraint index of about 1-12, said catalyst having been modified prior to use by treatment with compounds of germanium, tin and/or lead, and optionally phosphorus, the deposit a minor proportion of such elements on the zeolite.

Abstract: A process is disclosed whereby benzene is brought into contact with propylene, in the presence of a specified type of crystalline zeolite catalyst, to produce isopropylbenzene. The preferred zeolite catalysts are those having a silica to alumina ratio of at least about 12 and a constraint index, as herein defined, within the approximate range of 1-12. The process may be carried out in the liquid or the vapor phase at temperatures of from about 100.degree. C. to about 300.degree. C. and pressures ranging from 10.sup.5 N/m.sup.2 to 6.times.10.sup.6 N/m.sup.2.

Abstract: A process is provided for modifying ZSM-5 type zeolite catalysts with gaseous nitrogen-based treating agents in order to enhance the para-selective properties of such catalysts for the conversion of aromatic materials to dialkyl-substituted benzene compounds. Nitrogen-based treating agents include nitrogen dioxide and ammonia. Catalyst compositions so treated can be used in alkylation, transalkylation or disproportionation processes to provide product mixtures having exceptionally high concentrations of the para-dialkylbenzene isomer.