摘要:
A heavy aromatics feed is converted to lighter aromatics products, such as benzene, toluene and xylenes by contacting a C.sub.9 + aromatics fraction and benzene and/or toluene over a catalyst comprising a zeolite, such as ZSM-12, and a hydrogenation component, preferably platinum. The catalyst, complete with hydrogenation component, is treated to reduce aromatics loss. Treatment includes exposure to steam and/or sulfur after incorporation of the hydrogenation component. For additional stability and aromatics retention the steamed and/or sulfur treated catalyst is sulfided by cofeeding a source of sulfur. In a further embodiment of the invention a low hydrogen partial pressure is employed to retain aromatics.
摘要:
A layered composition of matter, MCM-56, has an X-ray diffraction pattern including lines at d-spacing values of 12.4.+-.0.2, 9.9.+-.0.3, 6.9.+-.0.1, 6.2.+-.0.1, 3.55.+-.0.07 and 3.42.+-.0.07 Angstroms and has been selectively modified so that the ratio of the number of active acid sites at its external surface to the number of internal active acid sites is greater than that of the unmodified material. When used as an additive to a large pore zeolite catalyst in the catalytic cracking of a petroleum feedstock, the modified MCM-56 gives an improved gasoline yield/octane relationship, an improved coke selectivity and a higher combined gasoline and potential alkylate yield than an identical catalyst containing unmodified MCM-56.
摘要:
A method for skeletal isomerization of linear olefins to iso-olefins, e.g., n-butenes to isobutylene, over a catalyst comprising medium pore zeolite, e.g., a zeolite selected from ZSM-22, ZSM-23, and ZSM-35. Treatment of the zeolite with dicarboxylic acid, e.g., oxalic acid, significantly reduces aging rate and increases cycle length of the catalyst.
摘要:
Relatively short chain alkyl aromatic compounds are prepared by alkylating an alkylatable aromatic compound with a relatively short chain alkylating agent under sufficient reaction conditions in the presence of a catalyst comprising zeolite MCM-56. The liquid phase syntheses of ethylbenzene and cumene are particular examples of such MCM-56 catalyzed reactions.
摘要:
A process for catalytically converting cyclohexanone oxime to epsilon caprolactam. The conversion catalyst is a crystalline aluminosilicate zeolite having a Constraint Index greater than 1 and a reduced surface acidity. The surface acidity is reduced by selective surface dealumination of the crystalline aluminosilicate zeolite by contacting the zeolite with dicarboxylic acid, such as oxalic acid.
摘要:
This invention relates to use of synthetic layered material MCM-56 as a sorbent and as a catalyst component in catalytic conversion of organic compounds. Examples of sorbent use include rapid sorption of hydrocarbons and separating at least one hydrocarbon component from a mixture of hydrocarbon components having differential sorption characteristics with respect to MCM-56. Examples of catalytic use include acid catalyzed reactions, such as cracking, aromatic compound alkylation, and isoalkane alkylation.
摘要:
A process for the selective surface dealumination of organic-containing zeolites by contacting the zeolite with dicarboxylic acid, such as oxalic acid. The treatment results in a reduction in surface acidity without a significant reduction in overall activity. The organic may be a directing agent used in the zeolite synthesis or introduced into the pores of the zeolite after thermal treatment.
摘要:
This invention relates to the catalyst composition resulting from the addition of phosphorus, and optionally, a matrix material, to a porous crystalline material having the structure of MCM-22, along with the method for making the catalyst composition, and the method for using the catalyst composition in catalytic cracking. It is desirable to improve the hydrothermal stability of the catalysts which are based upon porous crystalline materials having the X-ray structure of MCM-22 to increase the activity that the catalyst maintains after repeated cycles of steaming such as is experienced in the FCC process. It has been found that phosphorus addition to a porous crystalline material having the structure of MCM-22 improves the hydrothermal stability of the resulting catalyst. This improved catalyst is useful in organic conversion processes, e.g., catalytic cracking processes.
摘要:
There is provided a process for regenerating a coked catalyst comprising a zeolite and a noble metal such as platinum. The process involves treating the coked catalyst under somewhat mild oxidation conditions, whereby a sufficient portion of the coke is removed from the catalyst to restore the hydrocarbon sorption properties of the zeolite component to the level observed in the non-coked form. Surprisingly, the original activity of the catalyst is substantially restored, even though a substantial amount of coke remains on the regenerated catalyst.
摘要:
This invention relates to a new synthetic layered material, a method for its preparation and use thereof as a sorbent and as a catalyst component in catalytic conversion of organic compounds.