Enichem S.p.a

Enitecnologie S.p.a.

Other

Eniricerche S.p.a.

Enichem Synthesis S.p.a

Polimeri Europa S.p.a.

Enitechnologie S.p.a.

Versalis S.p.a.

Giannino Pazzuconi

Carlo Perego

Gianni Girotti

Oscar Cappellazzo

Giuseppe Bellussi

Giuseppe Terzoni

Angela Carati

Elena Bencini

Renzo Bignazzi

Riccardo Mansani

The present invention relates to an integrated process for the production of high purity 2,6-dimethylnaphthalene starting from hydrocarbon mixtures containing naphthalene and/or isomers of methylnaphthalene and/or isomers of dimethylnaphthalene and/or isomers of polymethylnaphthalene, and from an alkylating agent, preferably methanol, reacted in the presence of a methylated benzene solvent or mixture of various methylated benzene solvents, preferably selected from toluene, xylene and trimethylbenzene, and a catalyst consisting of ZSM-12 zeolite and an inorganic ligand.

Integrated process for the production of 2,6-dimethylnaphthalene

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.

Process for the preparation of 2,6-dimethylnaphthalene

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.

Method for the separation of zeolites

Process for the preparation of 2,6-dimethylnaphthalene comprising reacting with at least one aromatic hydrocarbon, in the presence of a zeolitic catalyst, a mixture of naphthalenes comprising a cut obtained by the fractionation of suitable petrochemical streams and subsequent treatment of the product thus obtained with a solid acid.

Process for the production of 2,6-dimethylnaphthalene from petrochemical streams

A catalytic composition is described for the alkylation and/or transalkylation of aromatic hydrocarbons consisting of beta zeolite, as such or modified by the isomorphous substitution of aluminum with boron, iron or gallium or by the introduction of alkaline and/or earth alkaline metals following an ion-exchange process, and an inorganic ligand, wherein the extrazeolite porosity, i.e. the porosity obtained by adding the mesoporosity and macroporosity fractions present in the catalytic composition itself, is such that a fraction of at least 25% is composed of pores with a radius higher than 100 .ANG., said composition being characterized by a total volume of extrazeolitic pores greater than or equal to 0.80 ml/g.

Catalytic composition and process for the alkylation and/or

Process for the preparation of cumene by the alkylation of benzene with propylene, catalyzed by zeolite Beta into which certain quantities of suitable alkaline, alkaline-earth or metallic cations have been introduced by ion exchange.

Process for the preparation of cumene

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Broni, Italy

Giannino Pazzuconi