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:
A layered catalyst suited to the catalytic cracking of heavy feeds comprises a core and a shell. The shell comprises at least 5 wt % of at least 1 molecular sieve having openings of at least 8 angstroms. The core comprises at least 10 wt % of at least 1 molecular sieve having openings comprising a 12 or less-membered ring and has a reduced, if any, content of said molecular sieve having openings of at least 8 angstroms, relative to its concentration in the shell. Suitable molecular sieve materials having openings of at least 8 angstroms include MCM-41, VPI-5, MCM-9 and layered metal oxides, e.g., pillared clays. The required molecular sieve of the core can include zeolite Y, Ultrastable Y or intermediate pore size zeolites such as ZSM-5. The shell which may further contain a metals passivator can act as a metals sink, and can remove metals from the unit by attrition. The catalyst is preferably prepared by forming the core and then coating or encapsulating the core with a shell material. The shell may also comprise an attritable coating of an amorphous rare earth oxide, aluminum oxide and aluminum phosphate composite, which traps metals.
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 from 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:
A catalytic cracking process is described featuring multiple risers in which a variety of hydrocarbon conversion reactions take place, a stripping unit in which entrained hydrocarbon material is removed from catalyst and a regeneration zone in which spent cracking catalyst is regenerated, which comprises:(a) catalytically cracking a relatively high boiling hydrocarbon charge material in a first riser in the presence of both a first catalyst component which is an amorphous cracking catalyst and/or a large pore crystalline cracking catalyst and a second catalyst component which is selected from zeolite Beta and/or medium pore crystalline silicate zeolite catalyst to provide a variety of products including naphtha and C.sub.3 and/or C.sub.4 olefin;(b) thermally cracking a C.sub.3-6 paraffin-rich charge material introduced to a second riser in a lower region thereof to provide light olefins; and,(c) catalytically converting at least a portion of the light olefins resulting from step (b) within the second riser in a higher region thereof in the presence mainly of a second catalyst component which is at least one member of the group consisting of zeolite Beta and a shape-selective medium pore crystalline silicate zeolite catalyst to provide a relatively high octane gasoline product.
摘要:
An improved process for stripping, or desorbing, entrained hydrocarbon material and, where present, sulfur-containing material, from a catalyst mixture recovered from a catalytic cracking reaction zone is described which comprises:(a) providing a quantity of catalyst mixture containing entrained hydrocarbon material and, optionally, sulfur-containing material, in at least one stripping zone in which a stripping gas removes said entrained hydrocarbon material and, where present, sulfur-containing material, the catalyst mixture comprising, as a first catalyst component, an amorphous and/or large pore crystalline cracking catalyst and, as a second catalyst component, a shape selective medium pore crystalline silicate zeolite catalyst, said first and second catalyst components being present in admixture within a common stripping zone or segregated into separate stripping zones; and,(b) conducting an exothermic reaction within the common stripping zone or within the separate stripping zone containing segregated second catalyst component, the heat released by the exothermic reaction providing an increase in the temperature of the catalyst in the stripping zone which results in the removal of a greater quantity of entrained hydrocarbon material and, where present, sulfur-containing material, than that occurring in the absence of such exothermic reaction.
摘要:
A catalytic cracking catalyst mixture and process are disclosed. The mixture comprises (a) a cracking catalyst containing a matrix and a large pore molecular sieve and (b) separate additive catalysts comprising at least one of a shape selective paraffin cracking/isomerization zeolite and a shape selective aliphatic aromatization zeolite. An exemplary catalyst mixture comprises dealuminized zeolite Y, optionally containing rare earth elements in an alumina-rich matrix, an additive catalyst of HZSM-5 in a matrix, and an additional additive catalyst of gallium ZSM-5 in a matrix. The alumina-rich matrix of the cracking catalyst acts a a sodium and metals sink. The large pore molecular sieve catalyst cracks large hydrocarbons to lighter paraffins and olefins. The shape selective paraffin cracking/isomerization component cracks/isomerizes the paraffins produced by the large pore moleular sieve. The shape selective aliphatic aromatization catalyst converts light paraffins and olefins into aromatics. A single shape selective zeolite, e.g., ZSM-5 with a controlled amount of an aromatization component such as gallium, may promote both paraffin cracking/isomerization and aromatization. The additive catalysts have physical properties, e.g., size, shape, density and attrition resistance which are substantially the same as the cracking catalyst.
摘要:
A catalytic cracking process and apparatus operates with multiple feed injection points to a riser reactor with several enlarged regions. An elutriable catalyst mixture is used, comprising a conventionally sized cracking catalyst and a faster settling, shape selective additive cracking catalyst. Straight run naphtha, and a light, H.sub.2 -rich aliphatic stream are added to the base of a riser reactor. A resid feed is added higher up in the riser, with a gas oil and recycled heavy cycle oil and naphtha streams added even higher up in the riser. The riser has an elutriating base, and an elutriating upper portion, which increase residence time of the shape selective zeolite additive relative to the conventionally sized cracking catalyst.
摘要:
A catalytic cracking catalyst mixture and process are disclosed. The mixture comprises (a) a cracking catalyst containing a matrix and a large pore molecular sieve and (b) separate particles of additive catalyst comprising at least one of a shape selective paraffin cracking/isomerization zeolite and a shape selective aliphatic aromatization zeolite. An exemplary catalyst mixture comprises dealuminized zeolite Y, optionally containing rare earth elements, in an alumina rich matrix and an additive catalyst of HZSM-5, and gallium ZSM-5 in a matrix. The alumina matrix of the cracking catalyst acts as a sodium and metals sink. The large pore molecular sieve catalyst cracks large hydrocarbons to lighter paraffins and olefins. The shape selective paraffin cracking/isomerization component cracks the paraffins produced by the large pore molecular sieve. The shape selective aliphatic aromatization catalyst converts light paraffins and olefins into aromatics. A single shape selective zeolite, e.g., ZSM-5 with a controlled amount of an aromatization component such as gallium, may promote both paraffin cracking/isomerization and aromatization. The additive catalyst is separable by physical means from the cracking catalyst, preferably by elutriation.
摘要:
A catalytic cracking process and apparatus operates with multiple feed injection points to a riser reactor with several enlarged regions. An elutriable catalyst mixture is used, comprising a conventionally sized cracking catalyst and a faster settling, shape selective additive cracking catalyst. Straight run naphtha, and a light, H.sub.2 -rich aliphatic stream are added to the base of a riser reactor. A resid feed is added higher up in the riser, with a gas oil and recycled heavy cycle oil and naphtha streams added even higher up in the riser. The riser has an elutriating base, and an elutriating upper portion, which increase residence time of the shape selective zeolite additive relative to the conventionally sized cracking catalyst.
摘要:
The present invention discloses a catalytic cracking operation featuring a single riser in which a variety of hydrocarbon conversion reactions takes place, a stripping unit in which entrained hydrocarbon material is removed from catalyst and a regeneration zone in which spent cracking catalyst is regenerated, which comprises:(a) converting a relatively high boiling charge material introduced to the riser at a lower level thereof in the presence of a first catalyst component which is an amorphous cracking catalyst and/or a large pore crystalline silicate cracking catalyst to provide lighter products including significant quantities of naphtha; and,(b) converting a naphtha charge material introduced to the riser at a higher level thereof in the presence of a second catalyst componet which is a shape selective medium pore crystalline silicate zeolite catalyst to provide a relatively high octane gasoline product.