摘要:
This invention is directed to a molecular sieve having acid catalyst sites and a method of maintaining the acid catalyst sites of a template-containing silicoaluminophosphate molecular sieve. The method comprises providing a template-containing silicoaluminophosphate molecular sieve and heating the molecular sieve in an oxygen depleted environment under conditions effective to maintain or preserve the number of acid catalyst sites. The heated molecular sieve exhibits at least one peak in the infrared region in a range of from 3630 cm−1 to 3580 cm−1. Preferably, the heated molecular sieve exhibits a combined peak area in the 3630 cm−1 to 3580 cm−1 range of at least 10% of a total peak area of all peaks in an infrared region between 4000 cm−1 to 3400 cm−1.
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 sources of water, silicon, aluminum, and phosphorus, as well as an organic template. In one aspect, the reaction mixture is heated at more than 10° C./hour to a crystallization temperature and is retained at the crystallization temperature or within the crystallization temperature range for a crystallization time from 16 hours to 350 hours to produce the silicoaluminophosphate molecular sieve. In another aspect, the reaction mixture is heated at less than 10° C./hour to a crystallization temperature from about 150° C. to about 225° C. and is then retained there for less than 10 hours to produce the silicoaluminophosphate molecular sieve. The molecular sieve can then be recovered from the reaction mixture and, preferably, used in a hydrocarbon conversion process, such as oxygenates to olefins.
摘要:
The invention relates to a conversion process for making olefin(s) using a molecular sieve catalyst composition. More specifically, the invention is directed to a process for converting a feedstock comprising an oxygenate in the presence of a molecular sieve catalyst composition, wherein the feedstock is free of or substantially free of metal salts.
摘要:
Disclosed is a method and apparatus for reducing the amount of metal catalyzed side-reaction byproducts formed in the feed vaporization and introduction system of a methanol to olefin reactor system by monitoring and/or maintaining the temperature of at least a portion of the feed vaporization and introduction system and/or of the feedstock contained therein below about 400° C., 350° C., 300° C., 250° C., 200° C. or below about 150° C. The temperature can be maintained in the desired range by jacketing at least a portion of the feed vaporization and introduction system, such as at least a portion of the feed introduction nozzle, with a thermally insulating material or by implementing a cooling system.
摘要:
Disclosed is a molecular sieve catalyst which contains molecular sieve-containing attrition particles and virgin molecular sieve, the attrition particles having been recycled from a catalyst manufacture process or from a reaction system. The catalyst can be used in a variety of catalytic reaction processes. A desired process is making olefins from an oxygenate feedstock. The recovery and use of the attrition particles in the catalyst is beneficial in minimizing waste, thereby reducing problems relating to both environmental and economic constraints.
摘要:
Disclosed is a molecular sieve catalyst which contains molecular sieve-containing attrition particles and virgin molecular sieve, the attrition particles having been recycled from a catalyst manufacture process or from a reaction system. The catalyst can be used in a variety of catalytic reaction processes. A desired process is making olefins from an oxygenate feedstock. The recovery and use of the attrition particles in the catalyst is beneficial in minimizing waste, thereby reducing problems relating to both environmental and economic constraints.
摘要:
Disclosed is a method for making olefin product from an oxygenate-containing feedstock. In the method, a silicoaluminophosphate molecular sieve catalyst is contacted with the oxygenate-containing feedstock in a reactor at an average catalyst feedstock exposure index of at least 1.0. The method produces lower coke yield and provides an olefin product which is low in C1-C4 paraffin content. The invention is particularly effective in producing an olefin product having a very low propane content.
摘要:
In a method of synthesizing a silicoaluminophosphate molecular sieve having 90+% CHA framework-type character, a reaction mixture is prepared comprising sources of water, silicon, aluminum, and phosphorus, as well as an organic template. In one aspect, the reaction mixture is heated at more than 10° C./hour to a crystallization temperature and is retained at the crystallization temperature or within the crystallization temperature range for a crystallization time from 16 hours to 350 hours to produce the silicoaluminophosphate molecular sieve. In another aspect, the reaction mixture is heated at less than 10° C./hour to a crystallization temperature from about 150° C. to about 225° C. and is then retained there for less than 10 hours to produce the silicoaluminophosphate molecular sieve. The molecular sieve can then be recovered from the reaction mixture and, preferably, used in a hydrocarbon conversion process, such as oxygenates to olefins.