摘要:
There is provided a method for selectivating a zeolite, such as ZSM-5 which may result in functionalization of the zeolite with at least one organosiliceous group of the formula, SiR.sub.n (OX).sub.4-n, where R is at least one hydrocarbyl group, n is 1 or 2 and X is Si or H. This selectivation method involves vapor phase treatment of a zeolite with an organosilicon compound having at least 2 silicon atoms. This organosilicon compound may be a silicone compound, such as hexamethyldisiloxane, or a silane compound such as hexamethyldisilane. This contacting may take place in the presence of hydrogen and an organic carrier. The functionalized zeolites may provide a catalyst which is both highly active and highly selective for converting aromatic hydrocarbons, especially alkylbenzene compounds, to products comprising the para-isomer of dialkylbenzenes. The disproportionation of toluene is an example of such a reaction.
摘要:
A process and catalyst for Shape Selective Hydrocarbon Conversions such as the regioselective disproportionation of toluene to para-xylene wherein hydrocarbon to be converted is passed over a catalytic molecular sieve which is trim selectivated with a reaction stream comprising toluene and a silicon-containing high efficiency p-xylene selectivating agent under toluene conversion conditions. The toluene disproportionation process attains a single-pass para-xylene product over 95% coupled with a toluene conversion of at least 15%. The present invention also includes the highly para-selective catalyst which results from the treatment of a catalytic molecular sieve with a high efficiency p-xylene selectivating agent under the recited conditions.
摘要:
Relatively short chain alkyl aromatic compounds are prepared by alkylating or transalkylating an alkylatable aromatic compound with a relatively short chain alkylating or transalkylating agent under sufficient reaction conditions in the presence of catalyst comprising zeolite MCM-49.
摘要:
The present invention provides a process for producing a selected paraffin from a reaction mixture containing(i) an acceptor olefin having the carbon backbone structure of said selected paraffin;(ii) a donor paraffin having a carbon backbone structure different from that of said selected paraffin;(iii) less than about 10 mole percent molecular hydrogen; which process comprises the steps of contacting said reaction mixture with a heterogeneous catalyst comprising active carbon in the absence of an added catalytic metal or metal compound to convert at least a portion of said acceptor olefin to said selected paraffin and to dehydrogenate at least a portion of said donor paraffin.
摘要:
There is provided a method for preparing a synthetic crystalline material from a reaction mixture including an organic directing agent selected from 1,4-diazacycloheptane (i.e. homopiperazine), azacyclooctane (i.e. heptamethyleneimine), aminocyclohexane (i.e. cyclohexylamine), aminocyclopentane (i.e. cyclopentylamine) and aminocycloheptane (i.e. cycloheptylamine). The crystalline material may be an aluminosilicate zeolite having considerable catalytic activity, e.g. for hydrocarbon conversion reactions.
摘要:
A method for enhancing the activity of a porous crystalline zeolite having a framework silica-to-alumina mole ratio of 25 or more which comprises contacting the zeolite with a solution comprising a hydrate of trivalent metal fluoride in aqueous media under conditions sufficient to cause incorporation of said metal in the framework of said zeolite.
摘要:
This invention relates to a new crystalline composition MCM-40, to a method for synthesizing said crystalline composition using diaminocyclohexane as a directing agent and to use of said crystalline composition as a catalyst component for organic compound, e.g. hydrocarbon compound, conversion.
摘要:
A spent acidic zeolite catalyst, e.g., ZSM-5 obtained from a hydrocarbon conversion process such as a catalytic dewaxing operation, is reactivated by contacting the spent catalyst with aqueous alkali metal carbonate and/or alkaline earth metal carbonate.
摘要:
Alumina-composited zeolite catalysts are activated by contact with an aqueous ammonium solution under ammonia gas pressure such that a pH of at least about 10 is maintained in the solution. The treated zeolite may thereafter be calcined without prior ammonium-exchange to provide the zeolite in the hydrogen form.