摘要:
High silica-containing zeolites having substantially no acid activity are enhanced by reacting the same with a solid binder such as alumina in the presence of water. Hydrocarbon conversion utilizing said enhanced zeolites is also disclosed.
摘要:
The hydrothermal stability of zeolites is improved by incorporating Group IB metal cations preferably Ag into the zeolite. The improved stability is useful in processes in which the zeolite is frequently exposed to water vapor at elevated temperature, for example, in processes where water is produced in the reaction or in the catalyst regeneration.
摘要:
A method of preparing a zeolite ZSM-12 type crystal which comprises crystallizing substantially pure ZSM-12 from a silica and optimally alumina gel mixture in the presence of a methyltriethylammonium cation, and the ZSM-12 product produced thereby.
摘要:
A new porous silico-crystal, designated as ZSM-48, a method of making same and the use thereof in catalytic conversion of organic compounds. The new product has a composition, expressed in terms of moles of anhydrous oxides per 100 moles of silica as follows:(0.05 to 5) N.sub.2 O:(0.1 to 10)M.sub.2 /.sub.n O:(0 to 4) Al.sub.2 O.sub.3 :(100) SiO.sub.2wherein M is at least one cation having a valence n, N is a mixture of C.sub.2 -C.sub.12 alkylamine and more preferably of C.sub.3 -C.sub.5 tetramethyl ammonium compound, and wherein the zeolite is characterized by the distinctive x-ray powder diffraction pattern shown in Table I.
摘要:
The invention provides a method of making large crystallite zeolites by a method comprising forming the zeolite in a medium containing a combination of two different alkylammonium cations or a combination of an alkylammonium cation and a metallic cation. In the combination at least one of the cations will have an ionic radius of from about 1.40 to the pore size of the specific zeolite.
摘要:
A layered catalyst contains a core of at least one, and preferably three, molecular sieve components within a shell layer of reduced molecular sieve content. A preferred catalyst consists of a core of a large pore molecular sieve, preferably a dealuminized Y-type zeolite, a shape selective paraffin cracking/isomerization component, preferably HZSM-5, and a shape selective aliphatic aromatization component, preferably gallium ZSM-5, within a shell of an alumina-rich, matrix. The shell can capture metals from the feeds being processed, it can act as a metals sink, and can remove metals form the unit by attrition. The catalyst is preferably prepared by forming the core and then coating or encapsulating the core with a shell having a reduced molecular sieve content. The shell may contain a pillared clay or other very large pore cracking component. The shell may be an attritable coating of an amorphous rare earth oxide, aluminum oxide and aluminum phosphate composite, which traps metals.
摘要:
There is provided a method for making large crystal size ZSM-5. This method involves the use of two organic cations, specifically tetrapropylammonium (TPA) and tetramethylammonium (TMA) cations, in the reaction mixture. This method further involves the use of a source of deliberately added alumina, such as aluminum sulfate, in the reaction mixture.
摘要:
A hydrous aluminosilicate adsorbent composition in which the active adsorbent is a mixture of non-fibrous clay with non-fibrous zeolite. The composition is useful as a feed supplement in animal husbandry, and as a topical adsorbent for veterinary use. The mixture has a high capacity for adsorption of ammonium cations, and a synergistically high selectivity for their adsorption. Beneficial effects as feed supplement may arise from lowering the amount of ammonia passed to the liver from the alimentary canal.
摘要:
There is provided a method for preparing a zeolite other than ZSM-5 from a reaction mixture comprising a mixed organic directing agent which is a combination of (a) an organic nitrogen containing compound such as an amine or a quaternary ammonium compound and (b) an alcohol and/or diol. Particular zeolites synthesized by this method include ZSM-22 and ZSM-23. The use of an alcohol or a diol may inhibit the coformation of ZSM-5. Especially when used to prepare ZSM-23, this method enables the preparation of more catalytically active ZSM-23 of reduced crystallite size and also enables the use of lower crystallization temperatures. Particular mixed organic directing agents for the preparation of ZSM-23 are combination of (a) pyrrolidine and (b) ethanol or ethylene glycol. Other factors which enhance the activity of ZSM-23 include the use of the following in the reaction mixtures for preparing ZSM-23: potassium ions; precipitated silica particles as sources of silica; and spray dried precipitated silica/alumina particles as sources of silica and alumina. The catalytic stability of alumina bound ZSM-23 catalysts is especially enhanced by steaming. Particular reactions which can be catalyzed by ZSM-23 made according to methods described herein include the dealkylation of ethylbenzene and the alkylation of benzene with ethylene.
摘要:
The invention describes the preparation of novel cracking catalysts by surface coating conventional cracking catalysts with passivators that act as metals traps. The coating of passivators is weakly bound to the catalyst so as to permit the coating to continuously attrit off during catalytic cracking. The continuous flaking off of the coating exposes a new surface of the coating.