摘要:
In the process of converting an aromatic feedstock to an alkyl-substituted mono-nuclear aromatic product by contacting the feedstock with a coke-selectivated ZSM-5 type catalyst at elevated temperature under conversion process coking conditions to produce said alkyl-1-substituted mononuclear aromatic product selectively, the improvement which comprises:regenerating the process coked catalyst in contact with a non-oxidizing atmosphere comprising an effective amount of hydrogen at a temperature of about 800.degree. F. to 1200.degree. F. to restore activity of the catalyst while retaining selectivity. Advantageously, the conversion involves alkylation, disproportionation and/or isomerization to produce at least one lower alkyl or dialkyl benzene product.
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:
Living plants and animals synthesize and often accumulate a wide variety of organic materials having a molecular weight greater than 150. These include different chemical types such as natural hydrocarbons including rubbery substances, natural resins, and natural glycerides such as oils and fats. These substances, formed in the anabolic process, are collectively called "anabolites".This invention provides a process for catalytically converting certain anabolites to liquid hydrocarbons useful for the manufacture of fuels such as gasoline and chemicals such as para-xylene. Crystalline aluminosilicate zeolites having an effective pore size of greater than about 5 Angstrom units are useful catalysts.
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:
A process is provided for alkylation or transalkylation of aromatic hydrocarbons by contacting same with an alkylating or transalkylating agent in a reaction zone maintained under alkylation/transalkylation effective conditions and in the presence of a catalyst comprising a crystalline aluminosilicate zeolite ZSM-35 and/or ZSM-38, said catalyst under said conditions being capable of affording a high and selective yield of desired alkyl-aromatic product while maintaining excellent aging properties.
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:
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 catalytic process is provided for isomerizing an isomerization feed containing an aromatic C.sub.8 mixture of ethylbenzene and xylene in which the para-xylene content is less than equilibrium which comprises contacting said feed, under conversion conditions, with a catalyst comprising a crystalline aluminosilicate zeolite having a crystal size of at least about 1 micron, 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 to yield an isomerization product characterized by a reduced ethylbenzene content and an enhanced para-xylene content.
摘要:
A process is provided for alkylation or transalkylation of aromatic hydrocarbons by contacting same with an alkylating or transalkylating agent in a reaction zone maintained under alkylation/transalkylation effective conditions and in the presence of a catalyst comprising a crystalline aluminosilicate zeolite characterized by a unique X-ray diffraction pattern, said catalyst under said conditions being capable of affording a high and selective yield of desired alkylaromatic product while maintaining excellent aging properties.
摘要:
A catalytic process is provided for the selective production of para dialkyl substituted benzenes containing alkyl groups of 1 to 4 carbon atoms, typified by para-xylene, by contacting, under conversion conditions, a hydrocarbon precursor selected from the group consisting of mono alkyl-substituted benzenes having 1-4 carbon atoms in the alkyl substituent, e.g., toluene, ethyl benzene, propyl benzene, or butyl benzene; a C.sub.2 -C.sub.15 olefin and a C.sub.3 -C.sub.60 paraffin, or mixtures thereof including mixtures of benzene with at least one of the aforementioned olefins or paraffins with a zeolite-containing catalyst characterized by a xylene sorption capacity greater than 1 gram/100 grams of zeolite and an ortho xylene sorption time for 30 percent of said capacity of greater than 10 minutes, said sorption capacity and sorption time being measured at 120.degree. C and a xylene pressure of 4.5 .+-.0.8 mm. of mercury, said catalyst comprising a crystalline aluminosilicate 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 and recovering from the resulting product mixture, a para dialkyl substituted benzene in an amount greater than the thermodynamic equilibrium concentration thereof in total dialkyl substituted benzenes produced.