Abstract: The present invention regards a catalytic composition comprising gallium, at least one element chosen in the group of the lanthanides, and a zeolite belonging to the MFI, MEL or MFI/MEL families, the crystal lattice of which is made up of silicon oxide and at least one metal oxide chosen from among aluminum oxide, boron oxide and gallium oxide. Preferably, in the catalytic compositions of the present invention a zeolite is used belonging to the MFI family characterized by crystallites which for at least 90% have diameters smaller than 500 ? and which can form agglomerates of submicron dimensions characterized by possessing at least 30% of the extrazeolitic porosity in the region of the mesopores. The catalytic compositions of the present invention can, in addition, contain rhenium. These catalytic compositions are useful in processes of aromatization of hydrocarbons containing from 3 to 6 carbon atoms, preferably, hydrocarbon mixtures containing olefins.

Abstract: A highly selective process is described for preparing 2,6-dimethylnaphthalene which comprises reacting a naphthalene hydrocarbon selected from naphthalene, methylnaphthalenes, dimethylnaphthalenes, trimethylnaphthalenes, polymethylnaphthalenes, and/or their mixtures with one or more benzene hydrocarbons selected from benzene, toluene, xylenes, trimethylbenzenes, tetramethylbenzenes, pentamethylbenzene and/or hexamethylbenzene, under at least partially liquid phase conditions and in the presence of a catalytic composition comprising a zeolite belonging to the MTW structural type and at least one element selected from P, B and Si. The process is preferably carried out in the presence of a methylating agent.

Abstract: The present invention regards a catalytic composition comprising gallium, at least one element chosen in the group of the lanthanides, and a zeolite belonging to the MFI, MEL or MFI/MEL families, the crystal lattice of which is made up of silicon oxide and at least one metal oxide chosen from among aluminum oxide, boron oxide and gallium oxide. Preferably, in the catalytic compositions of the present invention a zeolite is used belonging to the MFI family characterized by crystallites which for at least 90% have diameters smaller than 500 ? and which can form agglomerates of submicron dimensions characterized by possessing at least 30% of the extrazeolitic porosity in the region of the mesopores. The catalytic compositions of the present invention can, in addition, contain rhenium. These catalytic compositions are useful in processes of aromatization of hydrocarbons containing from 3 to 6 carbon atoms, preferably, hydrocarbon mixtures containing olefins.

Abstract: Aromatic hydrocarbon compounds are produced by a process of contacting one or more aliphatic hydrocarbons containing from 3 to 6 carbon atoms with a catalytic composition comprising (i) gallium, (ii) at least one lanthanide element, and (iii) a zeolite selected from the group consisting of the MIF family of zeolites, the crystal lattice of which consists of silicon oxide and aluminum oxide in a molar ratio of silicon oxide to aluminum oxide which is greater than 20 and less than 500, and is comprised of crystallites, at least 90% of which have diameters smaller than 500 ?.

Abstract: Process for the production of propylene starting from mixtures of hydrocarbons, prevalently olefins, the above hydrocarbons having a boiling point ranging from ?15° C. to +80° C., preferably from ?12° C. to +60° C., which comprises putting the above mixture of hydrocarbons in contact, under cracking conditions, with a large-pore zeolite having a molar ratio Silica/Alumina lower than 200, preferably ranging from 50 to 150.

Abstract: A description follows of a bimetallic catalyst, obtained by dispersing in sequence and alternating the precursors of the single metal components of the catalyst on a carrier, and a process for the synthesis of hydrogen peroxide by the direct reaction of hydrogen with oxygen, in a solvent medium containing a halogenated promoter and an acid promoter, in the presence of said catalyst.

Abstract: A process is described for the preparation of zeolitic catalysts in the form of microspheres, comprising zeolite and oligomeric silica, characterized by a high mechanical resistance. The process consists in subjecting to rapid drying the suspension, to which tetra-alkylorthosilicate is optionally added, resulting from the synthesis of zeolite by hydrothermal treatment at autogenous pressure of the reagent mixture containing tetra-alkylammoniumhydroxide as templating agent, and subjecting the product resulting from the drying to calcination.

Abstract: A highly selective process is described for preparing 2,6-dimethylnaphthalene which comprises reacting a naphthalene hydrocarbon selected from naphthalene, methylnaphthalenes, dimethylnaphthalenes, trimethylnaphthalenes, polymethylnaphthalenes, and/or their mixtures with one or more benzene hydrocarbons selected from benzene, toluene, xylenes, trimethylbenzenes, tetramethylbenzenes, pentamethylbenzene and/or hexamethylbenzene, under at least partially liquid phase conditions and in the presence of a catalytic composition comprising a zeolite belonging to the MTW structural type and at least one element selected from P, B and Si. The process is preferably carried out in the presence of a methylating agent.

Abstract: A process is described for the preparation of zeolitic catalysts in the form of microspheres, comprising zeolite and oligomeric silica, characterized by a high mechanical resistance. The process consists in subjecting to rapid drying the suspension, to which tetra-alkylorthosilicate is optionally added, resulting from the synthesis of zeolite by hydrothermal treatment at autogenous pressure of the reagent mixture containing tetra-alkylammoniumhydroxide as templating agent, and subjecting the product resulting from the drying to calcination.

Abstract: A process is described for the preparation of zeolitic catalysts in the form of microspheres, comprising zeolite and oligomeric silica, characterized by a high mechanical resistance. The process consists in subjecting to rapid drying the suspension, to which tetra-alkylorthosilicate is optionally added, resulting from the synthesis of zeolite by hydrothermal treatment at autogenous pressure of the reagent mixture containing tetra-alkylammoniumhydroxide as templating agent, and subjecting the product resulting from the drying to calcination.

Abstract: The object of the present invention relates to a simple, rapid and inexpensive process for effecting solid-liquid separations in the case of zeolites, also having small crystals. This process, which is particularly useful for the recovery of zeolite crystals in suspension in the crystallization water, comprises treating this suspension of crystals with an acid or one of its precursors and subjecting the resulting mixture to filtration or decanting. According to a particular aspect of the invention, the crystalline phase is separated in a mixture with oxides which can be used as ligands. Said oxides can be generated by the reagents of the zeolite preparation reagent mixture, not transformed into crystalline phase during the synthesis hydrothermal treatment, or they can be added to the suspension of crystals before the separation treatment, or again they can be generated by precursors suitably added to the crystallization slurry.

Abstract: A process for separating mixtures of hydrocarbon isomers on molecular sieves, including providing columns which include molecular sieves and function alternatively as secondary adsorption, primary adsorption, and desorption devices, feeding the mixtures of hydrocarbon isomers to a column functioning as the primary adsorption device for adsorbing isomers with greater selectivity towards the molecular sieves, feeding effluent of the mixtures from the column functioning as the primary adsorption device to a column functioning as the secondary adsorption device for adsorbing remaining isomers with greater selectivity, discharging isomers with a lower selectivity from the column functioning as the secondary adsorption device and a desorbing agent therein, feeding a desorbing agent to the column functioning as the desorption device, discharging isomers with a greater selectivity towards the molecular sieves and the desorbing agent in the column functioning as the desorption device.

Abstract: High transparency polymeric composition essentially consisting of: (1) from 30 to 95% of polystyrene; (2) from 70% to 5% of a composition of vinylarene-conjugated diene block copolymers; the percentage sum of (1) and (2) being equal to 100; the composition (2) consisting of: (2a) from 30 to 60% by weight of copolymers with a linear structure (2b) from 70% to 40% by weight of copolymers with a branched structure; the weight average molecular weight of the above composition (2) ranging from 30,000 to 400,000, preferably from 50,000 to 200,000.

Abstract: The invention relates to a purification method of cyclohexanone-oxime in a solution of solvents immiscible with water, which consists in washing said solutions with water or with an aqueous solution of a base having a pK<5 or in passing the solutions of cyclohexanone-oxime through a weakly alkaline ion exchange resin and, optionally, also through a weakly acid ion exchange resin.

Abstract: Organometallic complex having the formula (IAP)M(X)n which can be used for die formation of catalytic systems wherein: M is a metal selected from transition metals and lanthanides, in oxidation state “s” positive and different from zero; each X is independently a group of an anionic nature bound to the metal as an anion in an ionic couple or with a convalent bond of the “&sgr;” type; “n” expresses the number of X groups sufficient for neutralizing the formal “+s” charge of the metal M, and (IAP) represents a neutral bond consisting of a mono-imine of 2,6-diacylpyridine. Said complex is prepared with relatively simple methods and can be used, combined with a suitable co-catalyst, such as for example, an aluminoxane, as a catalyst in normal (co)polymerization processes of &agr;-olefins, and especially ethylene.

Abstract: Process for the separation of 2,6-dimethylnaphthalene from mixtures containing it, comprising the following operations: crystallization by the addition of a solvent and cooling of the mixture to a temperature higher than the formation value of the first eutectic; removal of the mother liquor by repeated washings; dissolution of the solid obtained; crystallization by cooling; filtration.

Abstract: The present invention relates to a process for the preparation of zeolitic catalysts comprising zeolite and oligomeric silica, which can be used in industrial reactors. The process consists in directly mixing the suspension, resulting from the synthesis of the zeolite, with an oligomeric silica sol, obtained from the hydrolysis of a tetra-alkyl ortho silicate in the presence of tetra-alkylammonium hydroxide, and in subjecting the mixture to rapid drying, by feeding to a spray-dry.

Abstract: Catalyst for steam cracking reactions consisting of pure mayenite having the general formula: 12CaO.7Al2O3 having an X-ray diffraction spectrum as indicated in Table I, obtained with a preparation process comprising the following steps: dissolution of salts containing calcium and aluminum with water; complexing of the dissolved salts by means of polyfunctional organic hydroxyacids; drying of the solution resulting from the completing in order to obtain a solid precursor product; calcination of the solid precursor product at a temperature ranging from 1300 to 1400° C. for at least two hours.

Abstract: A process is described for the continuous production of alcoholic or hydro-alcoholic solutions of hydrogen peroxide in a concentration ranging from 2 to 10% by weight and their direct use in oxidation processes. The process operates under high safety conditions and with a high productivity and molar selectivity towards the formation of H2O2.

Abstract: The present invention relates to a method for the removal of the templating agent from synthetic zeolites in general and in particular from silicalite, titanium silicalite and from composite materials containing zeolites and for their activation as catalysts. The method consists in treating the above materials with solvents in vapor phase and at a low temperature.