Abstract: The present invention comprises a hydrocarbon-conversion process using an improved MgAPSO-31 molecular sieve which demonstrates a favorable combination of conversion and selectivity in aromatics conversion. The sieve has a specific combination of crystal configuration, being limited in diameter and length, specified crystallinity as measured by an X-Ray Diffraction Index (XRDI), and a narrow range of magnesium content.

Abstract: A composition comprising an inner core and an outer layer comprising a molecular sieve has been prepared. The molecular sieve layer is characterized in that the molecular sieve layers are intergrown into each other. The inner core can be alpha alumina or other inert materials.

Abstract: The present invention comprises a hydrocarbon-conversion process using an improved MgAPSO-31 molecular sieve which demonstrates a favorable combination of conversion and selectivity in aromatics conversion. The sieve has a specific combination of crystal configuration, being limited in diameter and length, specified crystallinity as measured by an X-Ray Diffraction Index (XRDI), and a narrow range of magnesium content.

Abstract: A process for preparing beads of various compositions has been developed. The process involves preparing a reaction mixture of sources of framework elements of a molecular sieve. The reaction mixture can optionally contain molecular sieve seeds. Additional sources of the framework elements are added to give a concentration above the critical supersaturation limit thereby forming beads. Depending on the composition of the reaction mixture and the reaction conditions one can obtain beads which are substantially amorphous, to beads that are substantially crystalline molecular sieve. These beads in turn can be further processed to deposit a molecular sieve layer onto the beads.

Abstract: A process for preparing a layered composition has been developed. The composition comprises an inner core and an outer layer comprising a molecular sieve. The process involves providing a slurry comprising inner core particles and sources of the framework elements of the molecular sieve. To this slurry there are added nutrient(s), i.e. framework element sources thereby forming crystals of the molecular sieve which agglomerate onto the inner core. The process is carried out for a time sufficient to form a layer of desired thickness.

Abstract: A process for synthesizing a variety of molecular sieves has been developed. The process involves forming a reaction mixture comprising reactive sources of the framework elements plus at least one templating agent, reacting the mixture to at least partially crystallize the molecular sieve and provide a slurry of seed crystals and adding to it nutrients (sources) of the framework elements, e.g. aluminum and silicon in order to grow the seed crystals. The rate of addition of the nutrients is controlled such that it is substantially the same as the crystal growth rate and such that there is substantially no nucleation of new crystals. The seed crystals may be the same or different than the nutrients being added, thus allowing for a layered molecular sieve. When the crystals have reached a desired size, they are isolated by conventional techniques.

Abstract: In the operation of a gas phase polymerization reactor, a significant amount of production time and material can be lost during the transition from initial process conditions for the production of one product to the desired process conditions for the production of a second product. The present invention recognizes the synergy between the use of a membrane separation zone selective for the removal of hydrogen from the reactor effluent and the operation of the polymerization reactor during the transition period to significantly reduce the transition time and substantially reduce the production of off-specification product during the transition period.

Abstract: Control of a gas phase polymerization reactor is performed with the product melt index, the reaction temperature, and the partial pressure of the controlling reactant.