Question
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What is the latest progress in FCC catalysis to boost bottoms upgrading?
Mar-2022
Answers
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Heather Blair, Johnson Matthey, heather.blair@matthey.com
There are multiple catalytic options available for improving FCC bottoms upgrading, but one of the most effective methods of improving bottoms upgrading is using a separate particle additive. This gives the refiner ultimate flexibility to quickly change bottoms upgrading based on changing economics, feed, and/or unit constraints.
Johnson Matthey’s BCA-105 is a very effective bottoms cracking additive. The additive is made from highly selective matrix that provides the first cracking sites for larger FCC feed molecules. By doing this, the larger hydrocarbons (C20-C40) are cracked into smaller, more easily crackable hydrocarbons that can be further cracked on the Y-Zeolite of the FCC catalyst. This function allows lower Z/M base catalysts to continue cracking towards LCO, and higher Z/M base catalysts to convert towards gasoline and LPG. The additive can also be combined with ZSM-5 additives to increase LPG yield. Bottoms reduction of up to 25-30% is achievable using the additive.
The separate particle approach is more effective than simply adding extra matrix to the base catalyst. In FCC catalyst, zeolite coking is initially much faster than matrix. The coke precursors formed in Y-Zeolite migrate onto the matrix, therefore prematurely deactivating matrix cracking activity. In BCA-105 particles, the rate of matrix coking is much slower, resulting in higher matrix activity and more bottoms cracking. Also, metal dehydrogenation reactions occur relatively quickly, but the metals must first be reduced in the riser. BCA-105 enables cracking reactions to occur before metals being reduced, having a neutral and, in some cases, decrease in dry gas yield. Generally, when adding matrix to the base catalyst, it tends to make more hydrogen and coke due to the nickel and vanadium laydown on the base catalyst caused by the quick cracking reactions of the base catalyst Y-Zeolite. These metals then migrate to the base catalyst matrix. BCA-105 does not have the same effect as it does not contain any Y-Zeolite.
BCA-105 is an effective bottoms cracking additive that allows refiners flexibility without increasing coke or dry gas and impacting fluidisation. It is compatible with all FCC unit designs and base catalyst technologies.
Mar-2022
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