Catalysis 2024 Issue

Base catalyst VGO Base catalyst 5% PP-WPO/ 95% VGO ReNewFCC-S VGO ReNew FCC-SG 5% PP-WPO /95% VGO ReNewFCC-SG 10% PP-WPO /90% VGO

450F+ Conversion , wt%

450F+ Conversion , wt%

450F+ Conversion , wt%

450F+ Conversion , wt%

Figure 4 Comparative coke yields (top left), slurry yields (top right), gasoline yields (bottom left), and LPG olefin yields (bottom right) during co-processing of a polypropylene derived WPO in VGO for both ReNewFCC-SG (blue lines) and the based catalyst (orange lines). The solid lines represent the product yields from FCC cracking of VGO, while the dashed lines represent co-processing with the PP-WPO

water content and further processing will increase shelf life. FCC feed temperatures range from 300°F to 700°F (370°C), with most FCC units near 450°F (230°C). Mixing conventional gasoils with co-processing oils may increase pre-cracking. Many co-processing oils will have boiling and smoke points below process feed temperatures. These tem-

In addition, the free water content of the co-processing oil will far exceed most design dispersion steam rates. It is highly recommended to consult the FIT licensor when considering the type of oil and the concentration of co-pro- cessing oil to the nozzle. In some cases, the FIT licensor may recommend a completely different dispersion steam rate, different nozzle designs, or even the addition of sec- ondary feed nozzles for the introduction of bio-oils. Depending on the type and refinement of the oil, the metals content of a co-processing oil may vary greatly (see Table 1 ). Most of these metals will deposit throughout the FCC catalyst, promoting catalyst deactivation, dehydro- genation reactions, and/or pore plugging. In the refining industry, the effects of vanadium, sodium, iron, and calcium are widely known. Vanadium and sodium will deactivate the acid sites and can destroy the zeolite structure, reduc- ing catalytic activity. Eutectics Iron and calcium will form low melting point eutectics, form- ing a vitrified outer layer on the surface of the catalyst. This layer will plug pores and reduce catalyst accessibility (as measured by the KAI accessibility test). When co-process- ing oils, new types of contaminants are evident, and known ones may be observed at far higher levels. Potassium can reach levels greater than 100 wppm in the oil. This is sig- nificantly higher than the ~1 wppm vanadium found in gas - oils and ~10 wppm levels found in resid feeds. From ample commercial experience, it appears that potassium has half the catalyst deactivation effects compared to sodium. At

It is highly recommended to consult the FIT licensor when

peratures are well above the boiling point of water, leading to vaporisation, with the attendant increases in pressure from the steam volume expansion (1,700 times, and even more for super-heated steam) that entails. Co-processing oils such as FOGs will contain oxygen ranging approximately from 9 to 15%, with bio-oils reaching levels greater than 20%. Free water is another consideration for bio-oils, reaching as high as 50 vol% total (oxygen + free water) content. Feed injection technology (FIT) nozzles utilise high pressure, steam, and shearing action to atomise the feed. FIT nozzles are designed to utilise 2-9+ wt% dispersion steam to atom- ise the feed. The co-processing oils will result in a change in viscosity, boiling point, and atomisation requirement. considering the type of oil and the concentration of co-processing oil to the nozzle


Catalysis 2024

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