The present invention provides a modified composite molecular sieve, and a preparation method and an application of the modified composite molecular sieve. The modified composite molecular sieve comprises SiO.sub.2 and a composite molecular sieve that comprises molecular sieve MCM-22 and crystalline molecular sieve selected from at least one of ZSM-22, ZSM-23 and ZSM-48, wherein, the molecular sieve MCM-22 covers around the crystalline molecular sieve. The present invention further provides a catalyst and an application of the catalyst. The catalyst comprises a carrier and a noble metal loaded on the carrier, wherein, the carrier comprises a modified composite molecular sieve that is the modified composite molecular sieve provided in the present invention or the modified composite molecular sieve obtained with the method provided in the present invention. The catalyst that utilizes the composite molecular sieve as a carrier not only can decrease the solidifying point of waxy raw oil, but also can improve the yield of liquid product, is especially applicable to the isomerization dewaxing process of lube distillate, and has an advantage of remarkably improving the viscosity index of lube base oil.

Isomerization processes such as the isomerization of ethylbenzene and xylenes, are catalyzed by the new crystalline aluminosilicate zeolite comprising a novel framework type that has been designated UZM-55. This zeolite is represented by the empirical formula:
M.sup.+.sub.mRAl.sub.1-xE.sub.xSi.sub.yO.sub.z
where M represents a metal or metals selected from zinc or Group 1 (IUPAC 1), Group 2 (IUPAC 2), Group 3 (IUPAC 3) or the lanthanide series of the periodic table including sodium, potassium or a combination of sodium and potassium cations, R is an organic structure directing agent or agents derived from reactants R1 and R2 such as where R1 is diisopropanolamine and R2 is a chelating diamine, and E is an element selected from the group consisting of gallium, iron, boron and mixtures thereof. Catalysts made from UZM-55 have utility in various hydrocarbon conversion reactions.

Isomerization processes such as the isomerization of ethylbenzene and xylenes, are catalyzed by the new crystalline aluminosilicate zeolite comprising a novel framework type that has been designated UZM-55. This zeolite is represented by the empirical formula:
M.sup.+.sub.mRAl.sub.1-xE.sub.xSi.sub.yO.sub.z
where M represents a metal or metals selected from zinc or Group 1 (IUPAC 1), Group 2 (IUPAC 2), Group 3 (IUPAC 3) or the lanthanide series of the periodic table including sodium, potassium or a combination of sodium and potassium cations, R is an organic structure directing agent or agents derived from reactants R1 and R2 such as where R1 is diisopropanolamine and R2 is a chelating diamine, and E is an element selected from the group consisting of gallium, iron, boron and mixtures thereof. Catalysts made from UZM-55 have utility in various hydrocarbon conversion reactions.

The present application pertains to family of new crystalline molecular sieves designated SSZ-93. Molecular sieve SSZ-93 is structurally similar to sieves falling within the MTT structure type such as SSZ-32x, SSZ-32, ZSM-23, EU-13, ISI-4, and KZ-1 family of molecular sieves. SSZ-93 is characterized as having magnesium.

A process for preparing an alkylaromatics isomerisation catalyst comprising at least 0.01% wt of platinum on a carrier comprising of from 1 to 9 wt % of ZSM-12 and inorganic binder, which process comprises treating the carrier with an impregnation solution comprising base and an anionic platinum complex which impregnation solution has a pH of from 5.5 to 8; and a process for the isomerisation of alkylaromatics with the help of catalyst thus obtained.

A process for preparing an alkylaromatics isomerisation catalyst comprising at least 0.01% wt of platinum on a carrier comprising of from 1 to 9 wt % of ZSM-12 and inorganic binder, which process comprises treating the carrier with an impregnation solution comprising base and an anionic platinum complex which impregnation solution has a pH of from 5.5 to 8; and a process for the isomerisation of alkylaromatics with the help of catalyst thus obtained.

Process for dealkylation of alkylaromatic compounds which process comprises contacting an alkylaromatic feedstock with i) a first catalyst comprising a) a carrier comprising of from 20 to 70 wt. % of refractory oxide binder and of from 30 to 80 wt. % of dealuminated ZSM-5 having a crystallite size of from 500 to 10,000 nm and a silica to alumina molar ratio (SAR) of from 20 to 100; b) of from 0.001 to 5 wt. % metal chosen from the group consisting of Groups 6, 9 and 10; and optionally c) up to 0.5 wt. % of a Group 14 metal, and ii) a subsequent catalyst comprising a) a carrier comprising of from 20 to 70 wt. % of refractory oxide binder and of from 30 to 80 wt. % of ZSM-5 having a crystallite size of from 3 to 100 nm and a SAR of from 20 to 200; b) of from 0.001 to 5 wt. % of metal chosen from the group consisting of Groups 6, 9 and 10; and optionally c) up to 0.5 wt. % of a Group 14 metal.

Process for dealkylation of alkylaromatic compounds which process comprises contacting an alkylaromatic feedstock with i) a first catalyst comprising a) a carrier comprising of from 20 to 70 wt. % of refractory oxide binder and of from 30 to 80 wt. % of dealuminated ZSM-5 having a crystallite size of from 500 to 10,000 nm and a silica to alumina molar ratio (SAR) of from 20 to 100; b) of from 0.001 to 5 wt. % metal chosen from the group consisting of Groups 6, 9 and 10; and optionally c) up to 0.5 wt. % of a Group 14 metal, and ii) a subsequent catalyst comprising a) a carrier comprising of from 20 to 70 wt. % of refractory oxide binder and of from 30 to 80 wt. % of ZSM-5 having a crystallite size of from 3 to 100 nm and a SAR of from 20 to 200; b) of from 0.001 to 5 wt. % of metal chosen from the group consisting of Groups 6, 9 and 10; and optionally c) up to 0.5 wt. % of a Group 14 metal.

An aluminosilicate molecular sieve of STW framework type, designated herein as SSZ-110, and having a molar ratio of SiO.sub.2/Al.sub.2O.sub.3 of less than 100, is provided. SSZ-110 may be synthesized using an organic structure directing agent selected from one or more of 1,4-bis(2,3-dimethyl-1H-imidazolium)butane dications, 1,5-bis(2,3-dimethyl-1H-imidazolium)pentane dications, and 1,6-bis(2,3-dimethyl-1H-imidazolium)hexane dications. SSZ-110 may be used in organic compound conversion reactions and sorptive processes.

Disclosed is a process for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce two extract streamsone rich in paraxylene and a paraxylene-rich extract stream that is lean in ethylbenzene and an ethylbenzene-rich extract stream that is lean in paraxylene- and a paraxylene-depleted raffinate stream. A significant amount of the ethylbenzene is removed in the ethylbenzene-rich extract stream (at least enough to limit buildup in the isomerization loop), so the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy and capital intensive hydrogen recycle loop.