AM-13-18 FCCU Wet Scrubbing System Modifications to Reduce Air Emissions

Description:

Many fluidized catalytic cracking units (FCCUs) have wet scrubbing systems installed to reduce air emissions. A large percentage of these were designed to address only particulate and SOx emissions. Some of these may have been designed to achieve older emission mandates that are higher than those presently being mandated by regulatory authorities. A modification of these systems may be required to reduce particulate and/or SOx emissions as well as reduce NOx emissions. This paper addresses how these reductions can be achieved, while optimizing economics and system outage time to fit within turnaround schedules. First, reduction of SOx emissions is discussed. Methods to lower SOx levels from a current wet scrubbing system are reviewed along with the amount of emission reductions that can be achieved. Next, particulate emission reductions are discussed. The modifications required to an existing wet scrubbing system in order to reduce particulate emissions are reviewed, along with the details of these modifications. Finally, the addition of NOx control to an existing wet scrubbing system is discussed. Several approaches are presented, along with the merits and potential issues associated with the different approaches.