摘要:
The invention provides a method of making large crystallite zeolites by a method comprising forming the zeolite in a medium containing a combination of two different alkylammonium cations or a combination of an alkylammonium cation and a metallic cation. In the combination at least one of the cations will have an ionic radius of from about 1.40 to the pore size of the specific zeolite.
摘要:
There is provided a method for making large crystal size ZSM-5. This method involves the use of two organic cations, specifically tetrapropylammonium (TPA) and tetramethylammonium (TMA) cations, in the reaction mixture. This method further involves the use of a source of deliberately added alumina, such as aluminum sulfate, in the reaction mixture.
摘要:
Modified ZSM-5 type zeolite catalyst is prepared by controlled aging in a moving bed catalytic cracking unit. The modified catalyst exhibits significant olefin isomerization activity and reduced paraffin cracking activity. Hydrocarbons are cracked to products boiling in the motor fuel range, e.g., gasoline, by using the modified catalyst mixture comprising a ZSM-5 type zeolite and a conventional cracking catalyst. The ZSM-5 type zeolite is treated with partial pressure steam under conditions which increase the gasoline octane number of the product fuel without decreasing gasoline plus distillate yield. A process for changing a catalytic cracking unit's inventory from a conventional catalyst to a modified ZSM-5 type containing catalyst is also disclosed.
摘要:
There are provided aromatic conversion reactions for preparation of dialkyl benzenes, such as xylene and ethyltoluene, of enhanced para isomer content with a zeolitic catalyst composition of improved shape selectivity. The catalysts comprise certain zeolites which have been calcined at a high temperature of at least 649.degree. C. (i.e., 1200.degree. F.). These zeolites have a silica/alumina ratio of at least about 12 and a constraint index within the approximate range of 1 to 12. Examples of such zeolites include ZSM-5 and ZSM-11.
摘要:
A crystallization process employing microwave energy is described. The process is especially useful in the manufacture of porous crystalline materials.
摘要:
As synthesized by conventional technique, zeolite ZSM-5 is crystallized in the presence of substantial amount of tetraalkylammonium cations, the alkyl groups of which contain 2 to 5 carbon atoms, such as, for example, tetrapropylammonium. When synthesized in the conventional way, ZSM-5 contains tetraalkylammonium cations as well as a substantial amount of sodium ions. To obtain a more catalytically active form of ZSM-5, the sodium ions must be exchanged to very low levels. By synthesizing zeolite ZSM-5 according to the present method, i.e., in the presence of a combination of an amine and a halide in the presence of a mutual solvent and with a specifically defined reaction mixture composition, ZSM-5 having different organic nitrogen-containing cations but the same crystal structure as conventionally prepared ZSM-5 is obtained. The ZSM-5 prepared in accordance herewith is very low in sodium content as synthesized and has a crystal size of from about 0.05 microns to about 20 microns.
摘要:
A method of removing the organic cation from an organic cation-containing zeolite which comprises contacting the zeolite at low temperatures with an aqueous sodium hypochlorite solution.
摘要:
There are provided aromatic conversion reactions for preparation of dialkylbenzenes, such as xylene and ethyltoluene, of enhanced para isomer content with a zeolitic catalyst composition of improved shape selectivity. The catalysts comprise certain zeolites which have been calcined at a high temperature of at least 649.degree. C. (i.e., 1200.degree. F.). These zeolites have a silica/alumina ratio of at least about 12 and a constraint index within the approximate range of 1 to 12. Examples of such zeolites include ZSM-5 and ZSM-11.
摘要:
A method for selectively sorbing Group V-B element hydrides and derivatives thereof from an aqueous solution containing same which comprises contacting said solution under ion-exchange conditions with a crystalline zeolite material having a pore dimension greater than about 5 Angstroms, a Constraint Index between 1 and 12 and a SiO.sub.2 /Al.sub.2 O.sub.3 mole ratio greater than 12.
摘要翻译:从含有它的水溶液中选择性吸附VB族元素氢化物及其衍生物的方法,其包括在离子交换条件下使所述溶液与孔尺寸大于约5埃的结晶沸石材料接触,约束指数为1至12 和SiO 2 / Al 2 O 3摩尔比大于12。