level and the lot-to-lot variability can create challenges in refining operations. The FCC is especially well suited to handle this level of variation in properties due to the flexible nature of the process. The continuous replacement of catalyst offers a method to manage metals contaminants that is not available in other refining processes, and the ability to adjust operating conditions continuously to optimise against constraints makes the FCC an attractive place to consider co-processing of renewable feedstocks. Finally, the FCC process is known for its high degree of deoxygenation without the necessity for separate hydrogen addition, which means that the renewable fuels produced in the FCC have the potential for very low carbon intensity. However, not all feedstocks are easy to co- process in the FCC, and the FCC is not the only unit in the refinery used to co-process bio- based feedstocks. To help refiners determine the optimum processing scheme, Grace has developed a multi-stage advanced evaluation protocol to determine the suitability of new feedstocks, and we have applied this protocol across a wide variety of challenging bio-based feedstocks. Our protocol evaluates the physical and chemical compatibility of new bio-based feedstocks with existing FCC feedstock streams
and determines the FCC yield potential of the new feedstocks. Grace achieves the latter using pilot-scale testing units, up to and including our Davison Circulating Riser (DCR) Pilot Plant (see Figure 2 ). The DCR Pilot Plant offers an excellent set of capabilities for the evaluation of bio- based and alternative feedstocks. (Bryden, Weatherbee, & Habib, 2013). The DCR Pilot Plant is a continuously operated pilot plant with riser cracking, stripping, and regeneration capabilities, which closely simulates commercial FCC unit yields (Bryden, Predicting FCC unit performance with laboratory testing, 2013). Grace has licensed the DCR Pilot Plant technology to over 30 licensees, making it the leading commercially available technology for detailed evaluation of FCC dynamics on the pilot scale. Additionally, Grace has undertaken specific modifications to both the DCR and other technologies in our portfolio to enable these evaluations. While many research groups have published work on co-processing in the FCC using smaller-scale batch reactors, the continuous operation of the DCR offers a chance for many more significant insights. As an example, the continuous operation and larger scale of the DCR Pilot Plant allow for larger quantities
Figure 2 Grace’s Davison Circulating Riser Pilot Plant
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