Influence of catalyst conditioning on products in a continuously operated FCC pilot plant

In the past, the industrially proven and well established process of FCC has been used primarily to increase the product yield of the gasoline fraction in the refinery process. Economic and political considerations caused a shift of interest to other FCC-products (light olefins and LCO for example (1)) and the use of alternative feedstocks like vegetable oils (2). Another way to obtain the varying desired results is the development of new FCC catalysts. In this study, one such, as of yet non-commercial catalyst was used. The focus lay on the relation between catalyst activity and related composition of the products obtained. The experiments were conducted in a fully continuous FCC pilot plant with internal CFB design at the University of Technology in Vienna (Fig.1, Table 1). The catalyst used in the experiments was supplied in its fresh (unconditioned) state. On one hand, the aim was to achieve an increase in the yield of liquid products. On the other hand, an increase in the quality of LCO was a major goal. This was to be achieved by lowering the aromatics content in the LCO. To this end, the activity of the catalyst had to be lowered significantly which was achieved by conditioning of the catalyst. The conditioning of the catalyst was done in several steps through thermal treatment (heat only) and steaming (H2O vapor). In between the conditioning steps, FCC experiments were conducted and the resulting product compositions compared. The results clearly show a shift in the product spectra and quality, while the total fuel yield (TFY) remained nearly constant at around 80%. This validates the idea, that a reduction in catalyst activity directly impacts product quantity and quality in the way described above (Fig.2). Please click Additional Files below to see the full abstract