Resid hydrotreating catalysts

SOME PATENTS ON PORE STRUCTURE OF RESID HYDROTREATING CATALYSTS... 

Resid hydrotreating catalysts, developed in 1987 have been used together with a scale-and iron-removing catalyst for (1) the cracking and desulfurization of atmospheric residue, (2) the pretreatment of RFCC and (3) the cracking of vacuum residue. Approximately 7000 tons of industrial catalysts have been used in commercial units so far. 

A spent resid hydrotreating catalyst was regenerated on a seni-commercial scale using a proprietary process in which the Nl+V metals were first extracted and Chen the catalyst was decoked (ref. 14). The catalyst was a high surface area GoCrNo/ganuna-alumina desulfurization catalyst that had... 

Spent resid hydrotreating catalysts (bimodal CoHo) containing from 8 to 20 wci Ni-fV metals, calculated on a fresh catalyst basis, were commercially decoked without removing the contaminant metals and then tested for activity and particle attrition resistance. Selected decoked catalysts were also characterized to determine the causes for catalyst softening as a result of decoking. 

It is, therefore, required to hydrotreat the feedstock at a liquid mass velocity above a certain level to evaluate the life of the catalyst system in the resid hydrotreating. This level is proposed to be more than 70 lbs/ft hr (0.10 kg/m s) at which the pilot test was done. 

Y. Miyauchi c.s., Nippon Ketjen Seminar 1992, Correlation between catalyst performance in laboratory tests and commercial units for resid hydrotreating with the KFR catalyst system , Tokyo. 

The equivalent nickel content of the feed to the FCCU can vary from <0.05 ppm for a weU-hydrotreated VGO to >20 ppm for a feed containing a high resid content. The nickel and vanadium deposit essentially quantitatively on the cracking catalyst and, depending on catalyst addition rates to the FCCU, result in total metals concentrations on the equiUbrium catalyst from 100 to 10,000 ppm. 

Finally, PILC, REY-PILC, and a commercial equilibrium catalyst were evaluated at near constant conversion using a heavier feed, hydrotreated resid. The product yields are shown in Table III. Steam deactivated (D), REY-PILC, produced the same gasoline selectivity, LCO/HCO ratio, and coke yield as calcined PILC. The equilibrium catalyst which represents a more severely deactivated (E) sample had higher gasoline selectivity, lower coke yield, and lower HCO/LCO ratio. The higher coke yield of REY-PILC could be due to occlusion of high molecular weight hydrocarbons in the microstructure of the pillared clay. 

The deactivation of catalysts used in hydrotreating and hydroconversion of heavy petroleum feedstocks is associated with coking and metals deposition. Deactivation by metals has been thoroughly studied [1], but, little is known about deactivation by carbonaceous deposits. The initial decline in activity has often been attributed to this coke formation [2, 3, 4], However, in a recent study [51 it has been shown that coke deactivation can account for more than 50% of the deactivation in resid upgrading. 

Since different origins of resid feedstock are hydrotreated in the commercial fixed bed unit, an issue how to correct the commercial result is raised to compare them with pilot test results. The difference in the liquid mass velocity and the oil distributor efficiency between the pilot and commercial units is another important issue for determining the correlation between both units. The performance of catalyst was, therefore, evaluated under the normalized conditions applicable to the results of both units. 

Hydrothermal deactivation (catalyst), 170-171 Hydrothermal reaction, 4 Hydrotreated vacuum resid, 49... 

In reality, particularly with conventional hydrotreating type processes, the driving force may be insufficient to approach equilibrium. For example, the catalyst mediating the saturation reaction may have low activity for hydrogenation and/or the residence time for the reaction may be too brief, resulting in a basestock that falls well short of the equilibrium lines defined by the process H2 pressure. Furthermore, polar compounds present in the feed may hamper the inherent saturation activity by poisoning sites that mediate hydrogenation. 

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