Abstract:
An improved method of preparing a catalyst from a catalyst precursor concentrate is provided. The catalyst precursor concentrate, which is preferably phosphomolybdic acid, is treated at relatively low pressures in a specified manner.
Abstract:
A process for the optomization of the amount of sulfur introduced into a cyclic, or semi-cyclic reforming unit consistant with the dual objective of sulfiding a sulfur-sensitive polymetallic platinum catalyst, and minimizing the average sulfur present in the unit during an operating cycle. In accordance with such process, a sulfur-containing naphtha feed between reactor swings is first hydrofined to reduce the sulfur content of the feed, the product therefrom is then passed through a guard bed or reactor and contacted with a sulfur adsorbent essentially completely remove the feed sulfur to maximize catalyst activity, catalyst stability and C.sub.5.sup.+ liquid yield. At the time of, or just prior to, swinging on-stream a reactor which contains an unsulfided fresh, or unsulfided regenerated, reactivated sulfur-sensitive polymetallic platinum catalyst, the series of reactors is by-passed around the hydrofiner and guard chamber and the product from the hydrofiner fed directly into the series of reactors to sulfide the catalyst.
Abstract:
Methods are provided herein for co-processing of biocomponent feeds as well processing of mineral feeds in a reaction system at hydrogen partial pressures of about 500 psig (3.4 MPag) or less. The methods include using stacked beds of both CoMo and NiMo catalysts. The stacked catalyst beds provided unexpectedly high catalyst activity as the input feed to a reaction system was switched between a mineral feed and a feed containing both mineral and biocomponent portions. Additionally, use of stacked catalyst beds can allow for maintenance of the activity for the catalyst system in a reaction system while still achieving a desired activity for both types of feeds.
Abstract:
Hydrocarbon feeds can be hydrotreated in a continuous gas-phase environment and then dewaxed in a liquid-continuous reactor. The liquid-continuous reactor can advantageously be operated in a manner that avoids the need for a hydrogen recycle loop. A contaminant gas can be added to the hydrogen input for the liquid-continuous reactor to modify the hydrogen consumption in the reactor.
Abstract:
Diesel fuel is produced from a feedstock that is at least partially biocomponent in origin. A feedstock is treated in a reactor including one or more hydrotreating zones having a continuous gas phase. The liquid effluent from the hydrotreating zones is then hydroprocessed in a hydroprocessing zone having a continuous liquid phase, such as a hydroprocessing zone in the same reactor. The hydroprocessing zone can be operated under effective catalytic dewaxing conditions.
Abstract:
Technologies are described herein for regulating memory bandwidth usage in virtual machines via CPU scheduling. A virtual machine monitor (“VMM”) executing on a host computer detects excessive memory bandwidth usage by programs executing in a virtual machine on a processor of the host computer. The VMM may detect excessive memory bandwidth usage by monitoring cache-misses occurring in the processor, for example. Upon detecting excessive memory bandwidth usage, the VMM penalizes the virtual machine currently executing on the processor through the CPU-scheduling algorithm utilized to allocate processor time among the virtual machines.
Abstract:
The distillate catalytic hydrodesulfurization of hydrocarbon fuels wherein the optimum hydrogen treat gas rate to maximize desulfurization is determined and introduced into the reaction zone to maintain a controlled amount of hydrogen at the surface of the catalyst during hydrodesulfurization.
Abstract:
The distillate catalytic hydrodesulfurization of hydrocarbon fuels wherein the optimum hydrogen treat gas rate to maximize desulfurization is determined and introduced into the reaction zone to maintain a controlled amount of hydrogen at the surface of the catalyst during hydrodesulfurization.
Abstract:
Methods for hydroprocessing of hydrocarbon feedstocks, including hydrodesulfurization and hydrodenitrogenation, using rejuvenated supported metallic catalysts are provided. The supported metallic catalysts comprised of a Group VIII metal, a Group VIB metal, are rejuvenated by a process making use of these metals, an organic complexing agent, and optionally an organic additive. The rejuvenation includes stripping and regeneration of a spent or partially spent catalyst, followed by impregnation with metals and at least one organic compound. The impregnated, regenerated catalysts are dried, calcined, and sulfided.
Abstract:
Methods for rejuvenation of supported metallic catalysts comprised of a Group VIII metal, a Group VIB metal, making use of these metals, an organic complexing agent, and optionally an organic additive, are provided. The rejuvenation includes stripping and regeneration of a spent or partially spent catalyst, followed by impregnation with metals and at least one organic compound. The impregnated, regenerated catalysts are dried, calcined, and sulfided. The catalysts are used for hydroprocessing, particularly hydrodesulfurization and hydrodenitrogenation, of hydrocarbon feedstocks.