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Question

  • What level of SOx emissions from the FCC should we expect from current catalyst additives?

    Mar-2022

Answers


  • Corbett Senter, BASF Refining Catalysts, james.senter@basf.com

    SOx emissions from FCC depend on several factors (not just additive usage and performance), as SOx emission and the mechanism of SOx additives are both multi-step processes. SOx is formed when sulphur in feed enters the regenerator either as coke or due to poor stripping of FCC product from the circulating catalyst after the reactor. The sulphur in the regenerator is then combusted to SO2 and SO3 which can leave the FCC as emissions. SOx additives function by capturing SO3 in the regenerator, reducing the captured S-oxide on the additive in the riser and enabling conversion of S-oxide to H2S in the stripper, which causes the sulphur to exit with effluent from the reactor. Thus, the amount of sulphur in feed, feed type (type of sulphur compounds and metals in feed), stripper performance, catalyst circulation rate, regen operation, and the amount of SOx additive used will all play a role in SOx emissions. The key to understanding the expected emissions levels is to consider all these factors to develop a plan for reducing SOx emissions.

     

    Mar-2022