A molecular sieve has a silica/alumina molar ratio of 100-300, and has a mesopore structure. One closed hysteresis loop appears in the range of P/P.sub.0=0.4-0.99 in the low temperature nitrogen gas adsorption-desorption curve, and the starting location of the closed hysteresis loop is in the range of P/P.sub.0=0.4-0.7. The catalyst formed from the molecular sieve as a solid acid not only has a good capacity of isomerization to reduce the freezing point, but also can produce a high yield of the product with a lower pour point. The process for preparing the catalyst involves steps including crystallization, filtration, calcination, and hydrothermal treatment.

Disclosed are a catalyst system and its use in a process for the conversion of a feedstock containing C.sub.8+ aromatic hydrocarbons to produce light aromatic products, comprising benzene, toluene and xylene. The catalyst system comprises (a) a first catalyst bed comprising a first catalyst composition, said first catalyst composition comprising a zeolite having a constraint index of 3 to 12 combined (i) optionally with at least one first metal of Group 10 of the IUPAC Periodic Table, and (ii) optionally with at least one second metal of Group 11 to 15 of the IUPAC Periodic Table; and (b) a second catalyst bed comprising a second catalyst composition, said second catalyst composition comprising (i) a meso-mordenite zeolite, combined (ii) optionally with at least one first metal of Group 10 of the IUPAC Periodic Table, and (iii) optionally with at least one second metal of Group 11 to 15 of the IUPAC Periodic Table, wherein said meso-mordenite zeolite is synthesized from TEA or MTEA and having a mesopore surface area of greater than 30 m.sup.2/g and said meso-mordenite zeolite comprises agglomerates composed of primary crystallites, wherein said primary crystallites have an average primary crystal size as measured by TEM of less than 80 nm and an aspect ratio of less than 2.

An object of the present invention is to provide a method for producing oligosilane and in particular to provide a method that can efficiently produce oligosilane at lower temperatures and with an improved yield and selectivity. In the dehydrogenative coupling reaction of hydrosilane, oligosilane can be efficiently produced at an improved selectivity for oligosilane, and in particular at an improved selectivity for disilane, by carrying out the reaction in the presence of zeolite having pores with a minor diameter of at least 0.43 nm and a major diameter of not more than 0.69 nm.

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.

The hydroisomerization of a paraffinic hydrocarbon feedstock obtained from renewable sources is effectively achieved by passing the feedstock in the presence of hydrogen over a hydroisomerization catalyst comprising a crystalline metal silicate molecular sieve, in which a portion of the crystalline framework contains iron.

A method for preparing liquid fuel by direct conversion of syngas uses the syngas as reaction raw material and conducts a catalytic conversion reaction on a fixed bed or a moving bed. The catalyst is a composite catalyst formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of the component I is a metal oxide, and the component II is at least one of zeolites with one-dimensional ten-membered ring porous channels; and a weight ratio of the active ingredient in the component I to that in the component II is 0.1-20. The reaction process has high product yield and selectivity. The selectivity for liquid fuel composed of C.sub.5-C.sub.11 can reach 50-80%. The selectivity for aromatic hydrocarbon is less than 40% in C.sub.5-C.sub.11, while the selectivity for methane side product is less than 15%.

The instant disclosure provides a composition for fluid catalytic cracking of petroleum based feedstock into useful short chain olefins. The composition comprising: 76-86% of a non-zeolitic material; and 2-30% of at least one zeolite material, the percentage being based on weight of the catalyst composition, wherein one of the zeolites has been modified with 0.1-2.5 wt % metal. The said catalyst was found to be selective in enhancing the usable propylene gas content, while reducing the undesirable dry gas content of the cracked olefinic products. The present disclosure also provides a process for the preparation of the composition. The present disclosure also provides an apparatus (100) and process (200) for fluid catalytic cracking to obtain light olefins. The apparatus comprises a second riser (33) that includes a lower dense riser (2) and upper dilute riser (3). Further, the lower dense riser (2) has a diameter that is 1.1 to 2 times that of the upper dilute riser (3).

Systems and methods for upgrading a heavy oil feed to a light product comprising distillate fractions and olefins, the method including combining a heavy oil feed with a naphtha-based cracking additive to produce a mixed heavy oil feed; heating the mixed heavy oil feed with a nano-zeolite catalyst in the presence of steam to effect catalytic upgrading of the mixed heavy oil feed to produce lighter distillate fractions and olefins in an upgraded product, the upgraded product including at least about 30 wt. % olefins; and separating the lighter distillate fractions from the olefins.

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 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.