Effect of pretreatment on the performance of metal-contaminated fluid catalytic cracking (FCC) catalysts

Abstract

Effects of both hydrogen and methane pretreatment on the performance of metal-contaminated equilibrium fluid catalytic cracking (FCC) catalysts from a refinery were investigated. Both hydrogen and methane pretreatment at 700• C were proven to be advantageous since the yields of hydrogen and coke from sour imported gas oil (SIHGO) cracking decrease while light cycle oil (LCO) and gasoline yields increase. The catalysts pretreated with hydrogen have shown slightly better improvement than the catalysts pretreated with methane. The decrease in the yields of hydrogen and coke was attributed to decrease in the dehydrogenation activity of vanadium oxides, which are present at high concentrations on the equilibrium FCC catalysts. This decrease in dehydrogenation activity after the pretreatment was also confirmed by low hydrogen-to-methane ratio. It was found that reduced vanadium has lower dehydrogenation activity since it produces less coke and hydrogen compared to oxidized vanadium.Hydrogen transfer reactions were evaluated by measuring C 4 paraffin-to-C 4 olefin ratios. Hydrogen transfer reactions decreased with increasing metal concentration. Both hydrogen and methane pretreatment caused the hydrogen transfer reactions to increase. Improved hydrogen transfer reactions caused an increase in the gasoline range products.

A new way to enhance the porosity and Y-faujasite percentage of in situ crystallized FCC catalyst

“…However, in this case, it is evident that CAT-1 had higher selectivities to gasoline and light oil than CAT-0, and only a very slight increase was observed in the selectivities to dry gas and coke over the more active CAT-1. It has been thought that the dry gas and coke are yielded in the secondary reaction, [41][42][43] because of the diffusion restriction of the product molecules. Therefore, the more porous CAT-1 accelerated the diffusion of the product molecules, and thus decreased the massive formation of dry gas and coke.…”

Catalytic Cracking of C2–C3 Carbonyls with Vacuum Gas Oil

“…A higher paraffin-to-olefin ratio is an indicator of secondary hydrogen transfer reactions . Figure h shows that, as the acetol blending ratio increased, the C3 paraffin-to-olefin ratio was decreased from 0.28 to 0.16.…”

“…A higher paraffin-to-olefin ratio is an indicator of secondary hydrogen transfer reactions. 23 Figure 2h shows that, as the acetol blending ratio increased, the C3 paraffin-to-olefin ratio was decreased from 0.28 to 0.16. It indicates that the amount of secondary hydrogen transfer reactions was reduced, which led to a decrease in the gasoline yield and an increase in propylene yield (Figure 2i), which was also confirmed from the coke yield analysis.…”

Waste Management of Spent Petroleum Refinery Catalyst

“…This method is not only control product yield and product distribution from degradation, but also helps to reduce reaction temperature, which leads to economical process with valuable products. The spent FCC catalysts consist of 5-40% zeolite, which can significantly promote the economic potential of waste plastic recycling process [60][61][62][63]. In the process, heavy hydrocarbons are converted into light products containing C5-C11 liquid hydrocarbons under lower temperature.…”