摘要:
A process is disclosed for selectively producing one or more aromatic compounds selected from benzene, toluene, para-xylene, meta-xylene, ortho-xylene, ethylbenzene and mixtures thereof from a feed containing C6–C20 hydrocarbons and/or C6–C8 alcohols. The feed is initially subjected to a chemical conversion step to increase the concentration of C6–C8 paraffin and/or olefin precursors of said one or more aromatic compounds and then resulting precursor-enriched feed is then contacted with a dehydrocyclization catalyst under conditions of temperature and hydrogen partial pressure sufficient to effect dehydrocyclization of said paraffin and/or olefin precursors. A product rich in the desired aromatic compound(s) can then be recovered from the dehydrocyclization effluent.
摘要:
A crystalline material substantially free of framework phosphorus and comprising a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship: (n)X2O3:YO2, wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to about 0.5. The material exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.
摘要:
A process for converting hydrocarbons by contacting a hydrocarbon feedstream under hydrocarbon conversion conditions with a large crystal zeolite catalyst. The large crystal zeolite of the catalyst used in the hydrocarbon conversion process is made by heating an aqueous zeolite synthesis mixture under agitation to a temperature equal to or less than the effective nucleation temperature of the synthesis mixture. After this step, the aqueous synthesis mixture is heated in the absence of agitation to a temperature equal to or greater than the effective nucleation temperature of the aqueous zeolite synthesis mixture. The process finds particular application in hydrocarbon conversion processes where reduced non-selective acidity is important for reaction selectivity and/or the maintenance of catalyst activity, e.g., toluene disproportionation, dealkylation, alkylation, and transalkylation.