Turnaround Overview

FCC units routinely engage in a unit shutdown every three to five years. During this planned activity the unit is thoroughly inspected and significant maintenance is enacted to return the unit to an optimal physical condition to embark on the next three to five year operating cycle. Sometimes, these planned unit turnarounds provide an opportunity to incorporate new hardware technology in hopes of improved operational performance and/or enhanced flexibility ultimately leading to incremental profitability upon startup. 

During this time refiners should also take the time to evaluate the FCC catalyst inventory and take the necessary steps to prepare the inventory for post-startup operating conditions. The last three to six months of a typical operating cycle leading into the turnaround, many units face significant degradation to the operation. Many times, cyclone performance deteriorates which in turn leads to increased catalyst losses; which, in turn leads to the altering of particle size distribution for the catalyst remaining in the unit. Alternatively, air distribution in the regenerator can become unstable leading to a change in the temperature profile in the regenerator catalyst bed. These thermal excursions degrade catalyst zeolite reducing activity of the circulating inventory. Finally, units that are responsible for feed quality may be designed for run lengths aligned to the FCC cycle. As they approach the end of their operating cycle the feed quality may worsen, leading to a significant metals increase that negatively alter the catalyst performance. 

Catalyst Optimization

Over the years, ECI has worked with many refiners to develop a screening, classification, and catalyst change-out process to optimize unit startup after a period offline. As explained above, there are many factors leading up to a scheduled turnaround that can significantly degrade the quality of the catalyst in a unit's circulating inventory. A refiner can realize substantial yield and selectivity benefits immediately upon startup through the introduction of our TAR Optimized Catalyst. Replacing up to half of the total unit inventory while offline will help to improve the operating conditions immediately upon startup. 

TAR Optimized Catalyst can be customized entirely for anticipated post-TAR unit operating conditions. Tailored particle size distribution will improve catalyst fluidization and overall unit circulation and lead to a better overall unit stability. Decreased contaminate metals along with zeolite and matrix activity provide for maximized yields and selectivity as soon as the unit is returned to service. Traditionally, units suffer one to three months as post-TAR catalyst additions are increased in attempt to reach an optimized catalyst state.