摘要:
A mixture of aromatic hydrocarbons, comprising xylenes, is isomerized in the presence of ZSM-22 zeolite to produce a product stream wherein the proportion of para-xylene is substantially equal to the equilibrium ratio of the para-isomer. The process is conducted at about 500.degree. F. to about 1100.degree. F., at about 0 to about 3000 psig, optionally in the presence of hydrogen, and also optionally with the catalyst comprising about 0.005% to about 5.0% of a metal, e.g., platinum, palladium or cobalt, based on total catalyst weight.
摘要:
A process is provided for converting feedstock aromatic compounds by alkylation, transalkylation, disproportionation and/or isomerization over a catalyst comprising zeolite ZSM-58.
摘要:
There is provided a substantially binder-free catalytic molecular sieve which has been modified by being ex situ selectivated with a silicon compound. The ex situ selectivation involves exposing the molecular sieve to at least two silicon impregnation sequences, each sequence comprising an impregnation with a silicon compound followed by calcination. The catalyst may be used in a hydrocarbon conversion process, such as toluene disproportionation.
摘要:
There is provided a process for the selective production of para-xylene which comprises reacting toluene with methanol in the presence of a catalyst comprising a porous crystalline material having a Diffusion Parameter for 2,2 dimethylbutane of about 0.1-15 sec−1 when measured at a temperature of 120° C. and a 2,2 dimethylbutane pressure of 60 torr (8 kPa). The porous crystalline material is preferably a medium-pore zeolite, particularly ZSM-5, which has been severely steamed at a temperature of at least 950° C. The porous crystalline material is preferably combined with at least one oxide modifier, preferably including phosphorus, to control reduction of the micropore volume of the material during the steaming step.
摘要:
The present invention is a method of producing an ex situ selectivated catalytic molecular sieve for shape selective aromatic alkylation in which a catalytic molecular sieve having a reduced activity is modified by being exposed to at least two selectivation sequences, each sequence includes contacting the molecular sieve with a selectivating agent and subsequently calcining the contacted molecular sieve. The present invention is also a method of producing an ex situ selectivated catalytic molecular sieve for shape selective aromatic alkylation in which a catalytic molecular sieve is modified by being exposed to at least two selectivation sequences and then reduced in activity. The ex situ selectivated catalytic molecular sieves may optionally be further modified by in situ trim selectivation. The present invention is also a process for shape selective aromatic alkylation utilizing the modified molecular sieves.
摘要:
Methods for separation of substances are provided. The methods include contacting a mixture of at least two components in flowable conditions with mesoporous, crystalline materials termed M41S which also include MCM-41 materials. The mesoporous crystalline materials may be used in separations as is or functionalized.
摘要:
Disclosed is a zeolite base catalyst useful particularly for the selective production of para-dialkylsubstituted benzene. The catalyst comprises a porous crystalline zeolite having silica deposited thereon and having incorporated therein phosphorous. Described also in the process for making the catalyst and the parameters for the use of the catalyst in dialkylation processes.
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:
Mesoporous compositions and methods for preparing mesoporous and/or mesostructured materials from inorganic materials are provided. Various embodiments described herein relate to the preparation of mesoporous and/or mesostructured zeolites via a dehydroxylation pretreatment followed by a mesopore introduction step.
摘要:
There is provided a process for converting methanol and/or dimethyl ether to a product containing C2 to C4 olefins which comprises the step of contacting a feed which contains methanol and/or dimethyl ether with a catalyst comprising a porous crystalline material. The contacting is conducted in the presence of a cofed aromatic compound under conversion conditions including a temperature of about 350° C. to about 550° C. and a methanol and/or dimethyl ether partial pressure less than or equal to 50 psia (345 kPa). The porous crystalline material used in the catalyst has a pore size greater than the critical diameter of the aromatic compound and a Diffusion Parameter for 2,2-dimethylbutane of about 0.1 to about 26 sec−1 when measured at a temperature of 120° C. and a 2,2- dimethylbutane pressure of 60 torr (8 kPa), and the aromatic compound is capable of alkylation by the methanol and/or dimethyl ether under said conversion conditions.