Abstract: An improved zeolite catalyst having enhanced dealkylation activity is provided. The catalyst is prepared by incorporating fluorine into the zeolite structure. In another embodiment, a transition element such as nickel is additionally incorporated into the zeolite structure. The process for producing the catalyst also includes ion-exchange and calcining steps. A mordenite type catalyst has been found to be particularly effective. The catalyst of the present invention demonstrates improved activity for the dealkylation of polyalkylaromatic compounds found in residue from the alkylation process and in heavy reformate streams from refineries. A dealkylation process using the catalyst of the present invention is provided. The dealkylation process shows good selectivity for benzene and monoalkylated aromatic products, and catalyst stability, particularly at high reaction temperatures.

Abstract: Ethylbenzene is produced by alkylation over a split load of monoclinic silicalite alkylation catalysts having different silica/alumina ratios. A feedstock containing benzene and ethylene is applied to a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds. At least one catalyst bed contains a first monoclinic silicalite catalyst having a silica/alumina ratio of at least 275. At least one other catalyst bed contains a second monoclinic silicalite catalyst having a silica/alumina ratio of less than about 275. The alkylation reaction zone is operated at temperature and pressure conditions in which the benzene is in a gaseous phase to cause gas-phase alkylation of the aromatic substrate in the presence of the monoclinic silicalite catalysts to produce an alkylation product. The alkylation product is then withdrawn from the reaction zone for separation and recovery.

Abstract: An improved zeolite catalyst having enhanced dealkylation activity is provided. The catalyst is prepared by incorporating fluorine into the zeolite structure. In another embodiment, a transition element such as nickel is additionally incorporated into the zeolite structure. The process for producing the catalyst also includes ion-exchange and calcining steps. A mordenite type catalyst has been found to be particularly effective. The catalyst of the present invention demonstrates improved activity for the dealkylation of polyalkylaromatic compounds found in residue from the alkylation process and in heavy reformate streams from refineries. A dealkylation process using the catalyst of the present invention is provided. The dealkylation process shows good selectivity for benzene and monoalkylated aromatic products, and catalyst stability, particularly at high reaction temperatures.

Abstract: An alkylation/transalkylation process involving vapor phase alkylation of a benzene feedstock in a multi-stage alkylation zone having a plurality of series connected catalyst beds containing a pentasil aromatic alkylation catalyst, such as silicalite, coupled with intermediate separation and recirculation steps and liquid phase transalkylation over a transalkylation catalyst comprising a molecular sieve having a pore size greater than the pore size of the silicalite. The benzene containing feedstock is supplied to the multi-stage alkylation reaction zone along with a C.sub.2 -C.sub.4 alkylating agent operated under temperature and pressure conditions to maintain the benzene in the gas phase. Alkylated product is recovered from the alkylation zone and supplied to a benzene recovery zone for the separation of the benzene from the alkylation product. Benzene from the benzene recovery zone is recycled to the reaction zone.

Abstract: A process for the alkylation of an aromatic substrate over a molecular sieve zeolite catalyst involving supplying an aromatic substrate to a reaction zone containing the catalyst. The molecular sieve catalyst is an effective aromatic alkylation catalyst and comprises a modified zeolite beta alkylation catalyst having an intergrowth of a ZSM-12 crystalline framework within the crystalline framework of zeolite beta. An alkylating agent is also supplied to the reaction zone which is operated under temperature and pressure conditions effective to cause alkylation of the aromatic substrate by the alkylating agent. An alkylated substrate is recovered from the reaction zone.

Abstract: The present invention addresses heat integration in an alkylation/transalkylation process involving alkylation of an aromatic substrate with a C.sub.2 -C.sub.4 alklating agent coupled with separation to recover a monoalkylated aromatic product and liquid phase transalkylation of a polyalkylated product. Aromatic feedstock and a C.sub.2 -C.sub.4 alkylating agent are supplied to an alkylation reaction zone which is operated to produce an alkylated product. The output from the alkylation reaction zone initially travels through an arrangement of heat exchangers. From there, the alkylation effluent passes into the first separation zone which is operated to produce a lower boiling fraction comprising the aromatic substrate, which may be recycled to the alkylation reaction zone, and a higher boiling fraction comprising a mixture of monoalkylated and polyalkylated aromatics.

Abstract: Process for the production of ethylbenzene by alkylation over a silicalite alkylation catalyst with the subsequent transalkylation of diethylbenzene with the alkylation catalyst and conditions selected to retard xylene production and also heavies production. A feedstock containing benzene and ethylene is applied to a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds containing a pentasil molecular sieve alkylation catalyst which is silicalite of a predominantly monoclinic symmetry having a silica/alumina ratio of at least 275. The feedstock is supplied to the alkylation reaction zone to cause gas-phase ethylation of benzene at a flow rate to provide a space velocity of benzene over the catalyst to produce a xylene concentration in the product of about 600 ppm or less based upon the ethylbenzene content.

Abstract: A improved process is provided for the alkylation of aromatic compounds under at least partial liquid phase conditions, and in the presence of a zeolite-type alkylation/transalkylation catalyst. In accordance with the present process, a diluted aromatic hydrocarbon feedstock containing C.sub.5 -C.sub.7 olefins is brought into contact with a diluted olefinic feedstream in the presence of the alkylation/transalkylation catalyst. Prior to contact with the olefinic feedstream, C.sub.5 -C.sub.7 olefins present in the aromatic hydrocarbon feedstock are selectively hydrogenated.

Abstract: The present invention relates to a process for the conversion of polymers and particularly for the conversion of plastic containers or other plastic wastes. The process requires a minimum number of steps for treating typical industrial plastic wastes. The process comprises placing the mixed polymers in contact with a solvent that dissolves part of the polymers and separates the other fractions. The solvent fraction is subjected to treatment for the recovery of lower molecular weight stream that can be utilized in refining operations or other chemical operations.