摘要:
A crystalline material substantially free of framework phosphorus and comprising a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship: (n)X2O3:YO2, wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to about 0.5. The material exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.
摘要:
The synthesis of a crystalline material, in particular a high silica zeolite, having a chabazite-type framework is aided by the addition to the synthesis mixture of seeds of an AEI framework-type material. The chabazite-type product has a relatively small crystal size and exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.
摘要:
A method is disclosed of synthesizing a crystalline material comprising a CHA framework type molecular sieve and having a composition involving the molar relationship: (n)X2O3:YO2, wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to less than 0.01. The method comprises preparing a reaction mixture capable of forming said material, said mixture comprising a source of water, a source of an oxide of a tetravalent element Y and optionally a source of an oxide of a trivalent element X, wherein the reaction mixture is substantially free of fluoride ions added as HF; maintaining the reaction mixture under conditions sufficient to form crystals of the crystalline material; and than recovering the crystalline material. The reaction mixture comprises either a specific directing agent for directing the formation of a CHA framework type molecular sieve and/or a H2O:YO2 molar ratio of greater than 20. In one embodiment, the resultant crystalline material is free of stacking faults and/or any intergrown phase with an AEI framework type molecular sieve.
摘要:
In a method of synthesizing a silicoaluminophosphate molecular sieve having 90%+CHA framework type character, a reaction mixture is prepared comprising first combining a reactive source of aluminum with a reactive source of phosphorus to form a primary mixture that is aged. A reactive source of silicon and a template for directing the formation of the molecular sieve can then be added to form a synthesis mixture. Crystallization is then induced in the synthesis mixture. Advantageously, (i) the source of silicon comprises an organosilicate, (ii) the source of phosphorus optionally comprises an organophosphate, and (iii) the crystallized silicoaluminophosphate molecular sieve has a crystal size distribution such that its average crystal size is not greater than 5 μm. The molecular sieve can then preferably be used in a hydrocarbon (oxygenates-to-olefins) conversion process.
摘要:
In a method of synthesizing a silicoaluminophosphate molecular sieve having 90%+CHA framework type character, a reaction mixture is prepared comprising first combining a reactive source of aluminum with a reactive source of phosphorus to form a primary mixture that is aged. A reactive source of silicon and a template for directing the formation of the molecular sieve can then be added to form a synthesis mixture. Crystallization is then induced in the synthesis mixture. Advantageously, (i) the source of silicon comprises an organosilicate, (ii) the source of phosphorus optionally comprises an organophosphate, and (iii) the crystallized silicoaluminophosphate molecular sieve has a crystal size distribution such that its average crystal size is not greater than 5 μm. The molecular sieve can then preferably be used in a hydrocarbon (oxygenates-to-olefins) conversion process.
摘要:
In a method of synthesizing a silicoaluminophosphate molecular sieve having 90%+CHA framework type character, a reaction mixture is prepared comprising first combining a reactive source of aluminum with a reactive source of phosphorus to form a primary mixture that is aged. A reactive source of silicon and a template for directing the formation of the molecular sieve can then be added to form a synthesis mixture. Crystallization is then induced in the synthesis mixture. Advantageously, (i) the source of silicon comprises an organosilicate, (ii) the source of phosphorus optionally comprises an organophosphate, and (iii) the crystallized silicoaluminophosphate molecular sieve has a crystal size distribution such that its average crystal size is not greater than 5 μm. The molecular sieve can then preferably be used in a hydrocarbon (oxygenates-to-olefins) conversion process.
摘要:
Disclosed is a method of heat treating a molecular sieve. The method comprises providing a template-containing molecular sieve, heating the molecular sieve under conditions effective to remove a portion of the template from the molecular sieve, and cooling the heated molecular sieve to leave an amount of template effective to cover catalytic sites within the molecular sieve. A catalyst composition is also provided which comprises a molecular sieve having a microporous structure and a binder, wherein between 10 and 90 vol % of the microporous structure is occupied by a material, the material comprising a template or a carbonaceous residue of a template, and the catalyst composition exhibits a Davison Index of not greater than 30.
摘要:
Disclosed is a method of heat treating a molecular sieve. The method comprises providing a template-containing molecular sieve, heating the molecular sieve under conditions effective to remove a portion of the template from the molecular sieve, and cooling the heated molecular sieve to leave an amount of template effective to cover catalytic sites within the molecular sieve. A catalyst composition is also provided which comprises a molecular sieve having a microporous structure and a binder, wherein between 10 and 90 vol % of the microporous structure is occupied by a material, the material comprising a template or a carbonaceous residue of a template, and the catalyst composition exhibits a Davison Index of not greater than 30.
摘要:
Disclosed is a method of heat treating a molecular sieve. The method comprises providing a template-containing molecular sieve, heating the molecular sieve under conditions effective to remove a portion of the template from the molecular sieve, and cooling the heated molecular sieve to leave an amount of template effective to cover catalytic sites within the molecular sieve. A catalyst composition is also provided which comprises a molecular sieve having a microporous structure and a binder, wherein between 10 and 90 vol % of the microporous structure is occupied by a material, the material comprising a template or a carbonaceous residue of a template, and the catalyst composition exhibits a Davison Index of not greater than 30.
摘要:
This invention is directed to a method of making an olefin product from an oxygenate feedstock and a method of protecting catalytic activity of a silicoaluminophosphate molecular sieve. The methods comprise providing a silicoaluminophosphate molecular sieve having catalytic sites within the molecular sieve; shielding the catalytic sites to protect from loss of catalytic activity; and contacting the protected sieve in its activated state with an oxygenate feedstock under conditions effective to produce an olefin product before undesirable loss of catalytic activity. Undesirable loss in catalytic activity occurs when activated molecular sieve contacting the oxygenate feedstock has a methanol uptake index of at least 0.15.