摘要:
A synthetic, non-composited microporous membrane comprises a continuous array of crystalline molecular sieve material. A method is also provided for the preparation of the membrane, and methods are provided for using the membrane as a catalyst, or as a non-catalytic separation membrane for liquid or gaseous mixtures.
摘要:
A process is provided for catalytically converting cyclohexanone oxime to epsilon caprolactam. The conversion is characterized by exceptionally high selectivity and reduced rate of catalyst aging, even at single pass conversion above 90 percent. The conversion catalyst is a medium pore size crystalline zeolite exemplified by ZSM-5 which has low acid activity. Recycling unconverted oxime provides excellent ultimate yield of caprolactam.
摘要:
A method is provided for regeneration of a catalyst comprising a crystalline aluminosilicate zeolite characterized by a silica to alumina mole ratio of at least about 12, a constraint index, as hereinafter defined, within the approximate range of 1 to 12, which catalyst has undergone controlled precoking by exposing the same to a thermally decomposable organic compound at a temperature in excess of the decomposition temperature of said compound but less than about 1200.degree. F., at a hydrogen to organic compound mole ratio of between 0 and 1 to deposit at least about 1 weight percent coke thereon, such precoked catalyst having been deactivated by formation of a carbonaceous deposit thereon as a result of use of the same in catalytically converting an organic charge under conditions less severe, i.e., at a lower temperature and/or a higher hydrogen concentration than those employed during said precoking which comprises contacting the aged catalyst with an atmosphere comprising hydrogen at a temperature between about 800.degree. F. and about 1200.degree. F. and a pressure between about 0 and about 2000 psig for a period of time sufficient to at least partially restore the activity of the catalyst.
摘要:
A method is provided for increasing the catalytic activity of acid zeolite catalysts characterized by a silica to alumina mole ratio of at least 12 and a constraint index within the approximate range of 1 to 12, comprising contacting said zeolite catalysts with water for a sufficient treating time, temperature and water partial pressure to bring about said increased activity. The increase in catalytic activity is within a zone of enhanced activity, said zone is defined as encompassing all those conditions of treating time, temperature and water partial pressure and combinations thereof which yield catalytic activities greater than initial catalyst activity. The zeolite of enhanced activity of the method of the present invention can be utilized in improved acid catalyzed hydrocarbon conversion processes such as cracking, hydrocracking, alkylation, dealkylation, transalkylation, isomerization, dimerization, oligomerization, polymerization, addition, disproportionation, aromatization and hydration.
摘要:
A catalytic heat balanced cyclic process is provided for converting a charge consisting essentially of methanol, dimethyl ether or mixtures thereof to a hydrocarbon product rich in ethylene and propylene by contact, under specified conditions of temperature and contact time, with a catalyst comprising a crystalline aluminosilicate zeolite characterized by pores, the major dimension of which is less than 6 Angstroms and the capability, under such conditions, of producing less than about 20 weight percent methane in said hydrocarbon product, regenerating the catalyst so employed at a temperature between about 1200.degree. and about 1400.degree. F. to remove accumulated carbonaceous deposit therefrom and provide a source of hot regenerated catalyst for further contact, under controlled temperature conditions, with said charge.
摘要:
A catalytic process is provided for the selective production of para-xylene by disproportionation of toluene in the presence of a catalyst comprising a crystalline aluminosilicate zeolite having a silica to alumina ratio of at least about 12 and a constraint index within the approximate range of 1 to 12, which catalyst has undergone controlled precoking, i.e. selectivation, by exposing the same to a thermally decomposable organic compound at a temperature in excess of the decomposition temperature of said compound, generally greater than 1000.degree. F., but less than about 1200.degree. F., at a hydrogen to organic compound mole ratio between 0 and 1 to deposit at least about 2 weight percent coke thereon and thereafter contacting toluene with the resulting coke-containing catalyst under disproportionation conditions including a temperature between about 800.degree. F. and 1025.degree. F., and preferably between about 825.degree. F. and 1000.degree. F., at a hydrogen to toluene mole ratio greater than 1 and up to about 10 and recovering a product mixture containing para-xylene in an amount greater than the thermodynamic equilibrium concentration thereof in the total xylenes produced.
摘要:
The use of titania, zirconia, coprecipitated titania-zirconia or caustic on an inert solid inorganic support such as alumina or titania-zirconia to decompose formic acid in very dilute aqueous solutions thereof.
摘要:
Process for the alkylation of aromatic hydrocarbons by contacting same with an olefin alkylating agent in a reaction zone maintained under conditions such that said alkylation is accomplished in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12, said catalyst having been modified by prior thermal treatment to reduce the activity thereof, as determined by an alpha value, as described herein, to less than about 250 and preferably within the range of less than about 200 but greater than 10.
摘要:
A process is disclosed for the highly selective skeletal isomerization of linear olefin-containing organic feeds to iso-olefins at high levels of feed conversion wherein linear olefins, e.g., n-butenes, are contacted with catalyst comprising ZSM-35 under skeletal isomerization conditions which can include temperatures of 100 to 750.degree. C. The process uses a catalyst composition comprising ZSM-35, e.g., microcrystalline ZSM-35 having a crystal size whose largest dimension is no greater than 0.5 micron and whose ratio of its second largest dimension to said largest dimension ranges from 0.5 to 1. The process exhibits enhanced catalyst cycle life where the ZSM-35 is composited with a silica-containing matrix to provide a catalyst composite having a total pore volume greater than 0.6 cc/g or 300.sup.+ angstroms pore volume of greater than 0.1 cc/g.
摘要:
A method is disclosed for the double bond isomerization of alpha olefin-containing feeds, e.g., conversion of 1-butene-containing hydrocarbon streams to 2-butene-rich product streams, wherein oligomer by-products are minimized. The process uses a catalyst composition comprising a zeolite whose surface has been at least partially deactivated for acid catalyzed reactions by treatment with an aluminum chelating agent, e.g., oxalic acid, which possesses an average cross section diameter greater than that of the zeolite pores.