摘要:
There is provided a method for preparing a zeolite other than ZSM-5 from a reaction mixture comprising a mixed organic directing agent which is a combination of (a) an organic nitrogen containing compound such as an amine or a quaternary ammonium compound and (b) an alcohol and/or diol. Particular zeolites synthesized by this method include ZSM-22 and ZSM-23. The use of an alcohol or a diol may inhibit the coformation of ZSM-5. Especially when used to prepare ZSM-23, this method enables the preparation of more catalytically active ZSM-23 of reduced crystallite size and also enables the use of lower crystallization temperatures. Particular mixed organic directing agents for the preparation of ZSM-23 are combination of (a) pyrrolidine and (b) ethanol or ethylene glycol. Other factors which enhance the activity of ZSM-23 include the use of the following in the reaction mixtures for preparing ZSM-23: potassium ions; precipitated silica particles as sources of silica; and spray dried precipitated silica/alumina particles as sources of silica and alumina. The catalytic stability of alumina bound ZSM-23 catalysts is especially enhanced by steaming. Particular reactions which can be catalyzed by ZSM-23 made according to methods described herein include the dealkylation of ethylbenzene and the alkylation of benzene with ethylene.
摘要:
There is provided a method for synthesizing layered silicates such as magadiite and kenyaite. The source of silica used in this method is freshly precipitated from a silicate solution. For example, this silica source may be obtained by treating an aqueous solution of sodium silicate with sulfuric acid to form an amorphous silica precipitate. This silica precipitate is not dried to reduce its activity prior to use.
摘要:
A low acidity Group VIII metal-containing zeolite MCM-22 catalyst, said zeolite exhibiting an Alpha value of not greater than about 150, is provided for conversion of aliphatic C.sub.2 to C.sub.12 hydrocarbon(s) to olefin(s) and/or aromatic(s).
摘要:
Aliphatic C.sub.2 to C.sub.12 hydrocarbon(s) are converted to olefin(s) and/or aromatic(s) in the presence of a low acidity Group VIII metal-containing zeolite MCM-22 catalyst, said zeolite exhibiting an Alpha value of not greater than about 150.
摘要:
Synthesis gas (a mixture of hydrogen gas and carbon monoxide) is converted to hydrocarbons by flowing the gas first over iron-containing Fischer-Tropsch catalyst and then over a zeolite. The Fischer-Tropsch catalyst contains relatively little nitrogen as a result of its preparation by continuous precipitation at a pH ranging from about 6.6 to 6.9 and a temperature ranging from about 80.degree. to about 100.degree. C.
摘要:
Synthesis gas (a mixture of hydrogen gas and carbon monoxide) is converted to hydrocarbons by flowing the gas first over iron-containing Fischer-Tropsch catalyst and then over a zeolite. The Fischer-Tropsch catalyst contains relatively little nitrogen as a result of its preparation by continuous precipitation at a pH ranging from about 6.6 to 6.9 and a temperature ranging from about 80.degree. to about 100.degree. C.
摘要:
This invention relates to a method of preparing a metal-containing amorphous magnesia-alumina-aluminum phosphate catalyst support involving the admixture of an organic cation having a size equal to or greater than 2 Angstroms, the organic cation preferably being a tertiary or a tetraalkylammonium or phosphonium cation. The method permits recovery of a catalyst support having a controlled pore size distribution. The invention also relates to an improved catalytic support as well as an improved petroleum residua upgrading process comprising hydrotreating residua in the presence of the improved catalyst support.
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:
An improved method for passivating metals in a hydrocarbon feedstock during catalytic cracking has been discovered. The method involves contacting the feedstock with a passivating agent comprising a precipitated porous rare earth oxide, alumina, and aluminum phosphate precipitate. The passivating agent may be coated on a cracking catalyst, be part of the matrix of a cracking catalyst, or be added to the cracking operation as discrete particles.