Rare earths are incorporated in the fluid catalytic cracking (FCC) manufacturing recipe to achieve higher catalyst activity and to improve hydrothermal stability. Rare earths (REs) achieved these goals by enhancing catalytic activity and preventing loss of acid sites during normal unit operations. To address the specific needs of each FCC unit, catalyst manufacturers have traditionally formulated catalysts with various RE levels that allow for optimal unit performance. The level of REs in a specific catalyst formulation depends on the operational severity and product objectives for the specific FCC unit. As gasoline demand increased, refiners requested higher RE levels of their catalyst formulation. RE levels gradually increased over time, and at the end of 2010, the average was 3%, with several refineries running in excess of the average.
Fig. 1 shows 2010 historical data for Ecat samples analyzed by for REO. The data reflect all of the samples that were received and analyzed in the fourth quarter of 2010 before the RE price spike occurred. Although operational demands have not changed within the industry, current RE market conditions have put pressure on catalyst manufacturers, along with refiners, to reassess the role of REs in the FCC industry.
Fig. 1. Distribution of RE in FCC catalyst samples.
When looking at the catalytic options, it is critical to look at the total value, and not just the cost, of REs. Catalyst suppliers have actively helped their customers analyze their operations and determine when a drop in RE levels is beneficial. As will be discussed in this article, the cost/benefits and possible performance deficits of this option should be clearly understood before making a change.