Abstract: In order to maintain the surface area of an alumina catalyst over the course of operation and regeneration, a method of incorporating phosphorus into the alumina has been developed. By incorporating a small amount of phosphorus, the resulting catalyst is better able to withstand hydrothermal conditions, such as during a carbon burn step, which causes alumina surface area to degrade or decrease. Reduced surface area also desorbs chloride from the catalyst, lowering activity and increasing corrosion. Here, steam treatments have been used to simulate commercial hydrothermal stability and a critically small amount of phosphorus has been discovered which balances an increased surface area against decreased chloride retention. Increased surface area results from increased phosphorus, yet higher levels of phosphorus blocks ability to hold chloride. Moreover, X-ray data shows that an amount as low as 0.

Abstract: Reduced co-production of toluene and C9 and higher aromatics such as trimethylbenzene, methylethylbenzene, and diethylbenzene is achieved in processes for the isomerization of xylenes to close to equilibrium using a layered catalyst having a thin outer layer of molecular sieve and hydrogenation metal component on a core, wherein at least about 75 mass-% of the hydrogenation metal component is in the outer layer.

Abstract: The present invention comprises a process for producing propylene comprising the steps of contacting an olefin feed containing between about 40 and about 80 wt-% olefins and between about 20 and about 60 wt-% olefins and aromatics with a spherical catalyst to form a cracked product, the catalyst comprising about 30 to about 80 wt-% of a crystalline zeolite, the reaction conditions including a temperature from about 500° to 650° C., a hydrocarbon partial pressure of 70 to 280 kPa (10 to 40 psia), a liquid hourly space velocity in the range of 5 to 40 hr?1 and wherein propylene comprises at least 90 mol-% of the total C3 products.