A process for preparation of a bicyclic fused-ring alkane. In the presence of a bifunctional solid catalyst, one or more cyclitols undergo a CC coupling reaction with itself or each other at a temperature and in a nitrogen gas atmosphere, to produce a bicyclic alkane precursor mixture; then, the nitrogen gas is replaced by hydrogen gas, and the bicyclic alkane precursor mixture is hydrogenated or hydrodeoxygenated at a temperature and under a pressure, to produce the bicyclic fused-ring alkane. The proportion of the bicyclic fused-ring alkane in the product as prepared according to the process is not lower than 80 wt %.

Zeolites having highly dispersed bimetallic clusters, uniformly distributed in size and composition, encapsulated therein are disclosed. Metal encapsulation and alloying is conferred by introducing ligated metal cation precursors into zeolite synthesis gels, which are subsequently crystallized hydrothermally to form zeolites with metal cations occluded in the pores. The ligated cations are anchored to the zeolite framework via siloxane bridges which enforces their uniform dispersion throughout the zeolite crystals. Treatment of the crystallized zeolites in O.sub.2 and then H.sub.2 forms bimetallic clusters, which remain narrowly distributed in size and composition.

The present invention describes a process for the isomerization of paraffinic feedstocks operating at a temperature of between 200 C. and 500 C., at a total pressure of between 0.45 MPa and 7 MPa, at a hydrogen partial pressure of between 0.3 and 5.5 MPa, at an hourly space velocity of between 0.1 and 10 kilograms of feedstock introduced per kilogram of catalyst and per hour and using a catalyst comprising at least one metal of group VIII of the periodic table of elements, at least one matrix and at least one zeolite IZM-2, in which the ratio between the number of moles of silicon and the number of moles of aluminium of the zeolite IZM-2 network is between 25 and 55, preferably between 25 and 50, and preferably between 30 and 50.

Disclosed herein is a process for producing para-xylene comprising the steps of: (a) contacting a feedstock comprising toluene with a first catalyst under effective vapor phase toluene disproportionation conditions to disproportionate said toluene and produce a first product comprising benzene, unreacted toluene and greater than equilibrium amounts of para-xylene; and (b) contacting a feedstock comprising C.sub.9+ aromatic hydrocarbons and benzene with a second catalyst in the presence of 0 wt. % or more of hydrogen having a 0 to 10 hydrogen/hydrocarbon molar ratio under effective C.sub.9+ transalkylation conditions to transalkylate said C.sub.9+ aromatic hydrocarbons and produce a second product comprising xylenes.

The present invention relates to a zeolite catalyst for preparing light alkene by dehydrogenation of light alkane including a cocatalyst metal selected from tin (Sn), germanium (Ge), lead (Pb), gallium (Ga) and indium (In), and a preparation method of the same. The catalyst of the present invention is prepared by using the zeolite having a relatively high pore diameter, a structure of at least 12-membered ring, and a low acidity due to a SiO.sub.2/Al.sub.2O.sub.3 ratio of at least 50, so that it can suppress the inactivation of a catalyst caused by pore clogging due to the formation of coke. Therefore the catalyst of the present invention can be effectively used as a catalyst for the preparation of light alkene by dehydrogenation of light alkane.

A process is provided for producing xylene by transalkylation including introducing sulfur into a reactor containing a catalyst system prior to first introduction of hydrocarbon feedstock into the reactor; introducing hydrocarbon feedstock into the reactor upon the concentration of sulfur downstream of the catalyst system meeting a predetermined sulfur breakthrough concentration; continuing sulfur introduction for a period of time after first introducing hydrocarbon feedstock into the reactor; reducing the concentration of sulfur introduced upon T decreasing to or below a predetermined sulfur reduction threshold; and discontinuing sulfur introduction upon T decreasing to or below a predetermined sulfur shutoff threshold.

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.

The present invention refers to a process for oligomerization of acetylene in the presence of hydrogen and a solid catalyst.

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.