CO oxidation FCC additives

Combustion promoters are required to ensure smooth regenerator operation, control of afterburning and reduction of CO emissions. Afterburning occurs when carbon monoxide reacts exothermically with oxygen in the regenerator dilute phase. Because of the lack of catalyst to absorb the heat of CO combustion the dilute phase experiences a large increase in temperature – the most common constraint in FCC unit operations. A CO promoter is be used to accelerate this reaction in the regenerator dense phase (catalyst bed) where the heat of reaction is readily absorbed by catalyst particles leading to much lower temperature rises.

Promoters employ platinum group metals (pgms), supported on a high surface area alumina, to ensure a high metal dispersion. A high metal dispersion provides a high catalyst activity, allowing the optimum amount of precious metal to be used. In addition, high metal dispersion provides resistance to catalyst deactivation via sintering, therefore allowing less additive to be used. Furthermore, leveraging Johnson Matthey’s deep understanding of pgms, the amount of metal used is minimized while achieving outstanding catalyst performance.

All Johnson Matthey promoters have an attrition resistance, bulk density, and particle size distribution fully compatible with the circulating catalyst inventory and are available for delivery in a variety of packaging options.

Johnson Matthey also offers additive addition systems to accurately inject small quantities of additive throughout the day, allowing performance and cost optimization.

 

Platinum based promoters

Platinum promoters are very effective at converting CO to CO2 in the dense phase and controlling afterburn.

Johnson Matthey offers several platinum based promoters containing various levels of platinum. The lower activity grades (COPTM-250 and 375) are often used in FCC units with large regenerators, which can suffer from catalyst and air maldistribution and afterburn. These products have less platinum per particle and are used with a higher addition rate to ensure the platinum is evenly distributed in the regenerator. The higher activity grades (COP-550 and 850) provide a good balance of additive activity and cost and are used to reduce daily additions. 


Non-platinum based promoters

In addition to excellent afterburn control, platinum based promoters tend to increase regenerator NOx emissions. Non-platinum promoters have been developed for refiners who need to control afterburn and CO with minimum NOx emissions. JM’s non-platinum promoters have equivalent performance to the platinum-based promoters. 

COP-NPTM is an EPA approved non-platinum promoter used by many FCC units worldwide. It controls afterburn while reducing NOx emissions by over 70% compared to platinum based promoters.

COP-NP HD is a new product that employs advanced technology to improve metal dispersion and metal-support interaction. This new product controls afterburn with a lower daily cost for the end user.

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FCC additive team