Navigating the Energy Transition – Co-processing of chemical recycling products in Fluid Catalytic Cracking units

Written by:
Stefan Brandt, FCC Market Development Director, W. R. Grace & Co.
Rafael Gonzalez, Regional Marketing Manager, AP, W. R. Grace & Co.

As the Energy Transition progresses, multiple fronts are being considered to mitigate Global Warming as well as environmental pollution impacts from the use of fossil-derived products present at our modern daily life. At W.R. Grace & Co., we are paving the way to more sustainable refining and petrochemicals industries by investing in the development of technology solutions that will shape the refinery and petrochemical assets of the future. Meanwhile, we are also deploying strategies and products that can reinvent existing conversion assets like the Fluid Catalytic Cracking unit (FCC) –Figure 1-. Among all the initiatives, one important matter is recycling, particularly for waste plastics.

Waste plastics have been identified as one of the growing challenges globally. Key petrochemical feedstock demand like C2= and C3= mainly used as plastics precursors is expected to continue growing in the decades to come, with increased focus on integration between refineries and petrochemical sites to satisfy this growing demand – Figure 2-.

The valorization of plastic waste by mechanical or chemical recycling is considered to provide substantial benefits to the environment and the circularity of plastics. While mechanical recycling requires high purity of plastic waste, the limitations in collection and sorting of mixed plastic waste makes advanced chemical recycling another important route to eliminate pollution, enable circularity of plastics, lower dependency from fossil crude and produce lower carbon intensity products.

Global interest in advanced chemical recycling is growing and the process is expected to quickly develop at the commercial scale within the next decade -Figure 3-. Thermal and catalytic pyrolysis produce feedstocks for petrochemical and refinery processes like steam cracking, fluid catalytic cracking or hydroprocessing. Establishing strategic partnerships is key to shape new value chains for existing assets, like FCC units.

Risk mitigation planning is required to evaluate the feasibility of processing of advanced chemical recycling products in a crude refinery’s fluid catalytic cracking (FCC) unit and ensure that this opportunity is feasible and profitable. One of the challenges associated to these plastic-derived pyrolysis oils (PDPO) is the presence of contaminants that can severely damage catalyst performance. As seen in Figure 4, these contaminants can be present in remarkable contents and need to be properly evaluated as they can have huge impact on catalyst deactivation, impacting properties like for example diffusivity and activity [1].

In a recent collaboration with a European refining company [2] different PDPO qualities provided by a third party were evaluated as potential feed for their FCC units. One key risk identified was high contaminant content such as potassium (K), which could lead to stability deterioration even at low processing rates. Grace is currently developing a new solution with improved metals tolerance that would result in a better zeolite surface area retention -Figure 5-.

Bulk PDPO properties were suggesting good crackability relative to a traditional fossil-derived VGO, so once the contamination risk was tackled the co-processing potential was deemed as very promising, as can be seen in Table 1.

Table 1. Yield structure of FCC catalyst for different PDPO qualities evaluated at pilot plant and constant cat-to-oil.

In conclusion, PDPO cracking in existing assets like the FCC unit is a promising route in the chemical recycling value chain to convert waste plastic into valuable products such as lower carbon intensity transportation fuels and monomers for petrochemical production. A comprehensive risk management with a partner like W.R. Grace will help to identify the challenges and tackle them with the appropriate technology and technical service.

W.R. Grace continues looking ahead to the future of the refining industry and leading the technology advancements for challenges and opportunities ahead.

References

[1] Stefan Brandt et al, A promising new FCC feedstock: Heavy-cut pyrolysis oil from post-consumer plastic waste, Hydrocarbon Processing, June 2024.

[2] Stefan Brandt, The value of partnership in the Energy Transition. Co-processing of chemical recycling products in Fluid Catalytic Cracking units, LARTC, September 2024.

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