A hydrocarbon conversion catalyst composition which comprises ZSM-48 and/or EU-2 zeolite particles and refractory oxide binder essentially free of alumina in which the average aluminium concentration of the ZSM-48 and/or EU-2 zeolite particles is at least 1.3 times the aluminium concentration at the surface of the particles, processes for preparing such catalyst compositions and processes for converting hydrocarbon feedstock with the help of such compositions.

An improved hydroisomerization catalyst system and process for making a base oil product using a combined catalyst system comprising SSZ-91 molecular sieve and SSZ-95 molecular sieve. The catalyst system and process generally involves the use of a catalyst comprising an SSZ-91 molecular sieve and a separate catalyst comprising an SSZ-95 molecular sieve to produce dewaxed base oil products by sequentially contacting the catalysts with a hydrocarbon feedstock. The catalyst system and process provide improved base oil yield along with other beneficial base oil properties.

A hydrocarbon conversion catalyst composition which comprises ZSM-48 and/or EU-2 zeolite particles and refractory oxide binder essentially free of alumina in which the average aluminium concentration of the ZSM-48 and/or EU-2 zeolite particles is at least 1.3 times the aluminium concentration at the surface of the particles, processes for preparing such catalyst compositions and processes for converting hydrocarbon feedstock with the help of such compositions.

A family of new crystalline molecular sieves designated SSZ-91 is disclosed, as are methods for making SSZ-91 and uses for SSZ-91. Molecular sieve SSZ-91 is structurally similar to sieves falling within the ZSM-48 family of molecular sieves, and is characterized as: (1) having a low degree of faulting, (2) a low aspect ratio that inhibits hydrocracking as compared to conventional ZSM-48 materials having an aspect ratio of greater than 8, and (3) is substantially phase pure.

A hydrocarbon conversion catalyst composition which comprises dealuminated ZSM-48 and/or EU-2 zeolite and a refractory oxide binder essentially free of alumina, processes for preparing such composition and processes for converting hydrocarbon feedstock with the help of such compositions.

The invention relates to a catalyst composition which comprises a carrier material component and at least one metal component that is supported on the carrier material component. The carrier material component comprises a ZSM-12 type zeolite, a EU-1 type zeolite, and an inorganic binder. The metal component may include a Group VIII metal. The invention further relates to a process for preparing the catalyst and using it in a process for the isomerisation of alkylaromatics.

A hydrocarbon conversion catalyst composition which comprises ZSM-48 and/or EU-2 zeolite particles and refractory oxide binder essentially free of alumina in which the average aluminium concentration of the ZSM-48 and/or EU-2 zeolite particles is at least 1.3 times the aluminium concentration at the surface of the particles, processes for preparing such catalyst compositions and processes for converting hydrocarbon feedstock with the help of such compositions.

A process is described for preparing a catalyst comprising at least one zeolite with a modified EUO structure type, at least one matrix and at least one metal from group VIII of the periodic classification of the elements. Said catalyst is used in a process for the isomerization of an aromatic feed comprising at least one compound containing eight carbon atoms per molecule.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of a first and a second catalyst composition under conversion conditions effective to produce said lighter aromatic products comprising benzene, toluene and xylene. In the process, the C.sub.8+ aromatic hydrocarbons are dealkylated to form C.sub.6-C.sub.7 aromatic hydrocarbon and the C.sub.2+ olefins formed are saturated. The remaining C.sub.8+ aromatic hydrocarbons are transalkylated with the C.sub.6-C.sub.7 aromatic hydrocarbon. The first and second catalyst compositions each comprise a zeolite, a first metal, and optionally a second metal, and are treated with a source of sulfur and/or a source of steam.