摘要:
The present invention provides various processes for selectively removing undesirably sized catalyst particles from a reaction system. In one embodiment, a plurality of catalyst particles, having a first median particle diameter, is withdrawn from the reaction system and is directed to a separation unit such as a counter flow cyclone separator. In the separation unit, the particles are separated into a small catalyst stream and a large catalyst stream, the small catalyst stream having a second median particle diameter less than the first median particle diameter, and the large catalyst stream having a third median particle diameter greater than the first median particle diameter. At least a portion of the small or large catalyst stream is then directed back to the reaction system in order to maintain a desirable particle size distribution therein.
摘要:
This invention relates to processes for converting oxygenates to olefins that include a step of pretreating molecular sieve used in the conversion reaction with a C4–C7 olefin composition, which contains one or more C4–C7 olefins. Fresh or regenerated molecular sieve, which is low in carbon content, is contacted or pretreated with the olefin composition to form a hydrocarbon co-catalyst within the pore structure of the molecular sieve, and the pretreated molecular sieve containing the co-catalyst is used to convert oxygenate to a lighter olefin product.
摘要:
The present invention provides a process for making an olefin product from an oxygenate feedstock which comprises:a) contacting the feedstock in a reaction zone with a catalyst comprising i) a molecular sieve having defined pore openings and ii) a CO oxidation metal, under conditions effective to convert the feedstock into an olefin product stream comprising C2–C3 olefins and to form carbonaceous deposits on the catalyst so as to provide a carbon-containing catalyst;b) contacting at least a portion of the carbon-containing catalyst with a regeneration medium comprising oxygen in a regeneration zone comprising a fluid bed regenerator having a dense fluid phase and a dilute fluid phase under conditions effective to obtain a regenerated catalyst portion, wherein the difference between the temperature of the dilute phase and the temperature of the dense phase is no greater than 100° C.;c) introducing said regenerated catalyst portion into said reaction zone; andd) repeating steps a)–c).
摘要:
This invention relates to processes for converting oxygenates to olefins and olefins to polyolefins. The processes include a step of pretreating molecular sieve used in the conversion of oxygenate to olefin with a dimethyl ether composition. Fresh or regenerated molecular sieve, which is low in carbon content, is contacted or pretreated with the dimethyl ether composition to form a hydrocarbon co-catalyst within the pore structure of the molecular sieve, and the pretreated molecular sieve containing the co-catalyst is used to convert oxygenate to a lighter olefin product.
摘要:
Disclosed is a method and system for reducing the formation of metal catalyzed side-reaction byproducts formed in the feed vaporization and introduction system of a methanol to olefin reactor system by forming and/or coating one or more of the heating devices, feed lines or feed introduction nozzles of/with a material that is resistant to the formation of metal catalyzed side reaction byproducts. The invention also may include monitoring and/or maintaining the temperature of at least a portion of the feed vaporization and introduction system and/or of the feedstock contained therein below about 400° C., 350° C., 300° C., 250° C., 200° C. or below about 150° C. The temperature can be maintained in the desired range by jacketing at least a portion of the feed vaporization and introduction system, such as at least a portion of the feed introduction nozzle, with a thermally insulating material or by implementing a cooling system.
摘要:
There is provided a zeolite bound zeolite catalyst which does not contain significant amount of non-zeolitic binder and can be tailored to optimize its performance and a process for converting hydrocarbons utilizing the zeolite bound zeolite catalyst. The zeolite bound zeolite catalyst comprises core crystals containing first crystals of a first zeolite and optionally second crystals of a second zeolite having a composition, structure type, or both that is different from said first zeolite and binder crystals containing third crystals of a third zeolite and optionally fourth crystals of a fourth zeolite having a composition, structure type, or both that is different from said third zeolite. If the core crystals do not contain the second crystals of the second zeolite, then the binder crystals must contain the fourth crystals of the fourth zeolite. The zeolite bound zeolite finds application in hydrocarbon conversion processes, e.g., catalytic cracking, alkylation, disproportional of toluene, isomerization, and transalkylation reactions.
摘要:
There is provided a process for converting hydrocarbons which utilizes a zeolite bound zeolite catalyst that has enhanced performance when utilized in hydrocarbon conversion processes, e.g., catalytic cracking, alkylation, disproportionation of toluene, isomerization, and transalkylation reactions. The catalyst comprises a first zeolite having particles of greater than about 0.1 micron average particle size and a binder comprising second zeolite particles having an average particle size less than said first particles.
摘要:
There is provided a process for converting hydrocarbons which utilizes a zeolite bound zeolite catalyst that has enhanced performance when utilized in hydrocarbon conversion processes, e.g., catalytic cracking, alkylation, disproportionation of toluene, isomerization, and transalkylation reactions. The catalyst comprises a first zeolite having particles of greater than about 0.1 micron average particle size and a binder comprising second zeolite particles having an average particle size less than said first particles.
摘要:
The present invention is a process for regenerating deactivated catalyst or redispersing catalytic metal in a fresh catalyst comprising at least one Group VIII catalytic metal, zeolite, an inert binder. The process comprises coke burn, hydrogen reduction, catalyst conditioning, oxychlorination, low pressure stripping, and low pressure final hydrogen reduction.