PTQ Q4 2023 Issue

Transforming refineries’ opportunities through FCC

Pursuing a sustainable path for recycled and renewable feedstocks

Lucas Dorazio and James Fu BASF Corporation

T he integration of recycled and renewable waste streams into chemical value chains is a challenging topic driven by the need to make circularity in the pro- duction of chemicals and fuels a reality. Increased circularity in manufacturing will come from both chemically recycling fossil carbon from waste streams such as plastics or tyres and inserting renewable feeds such as lipid-based oils or oils from biomass wastes into refining processes. Using existing refinery processes for upgrading these materials will offer the opportunity to reduce implementation costs and allow for a gradual transition from conventional oils. However, the properties of oils derived from recycled and renewable wastes will vary considerably and, in some cases, depart significantly from the properties of conven - tional oils. Some feedstocks will be much more challenging to integrate into existing refinery assets. One process available to many refiners is fluid catalytic cracking (FCC). For more than 80 years, the process has proven valuable for converting heavy, low-value fractions of conventional oil into high-value products. Inherent in the design and operation of the FCC is a flexibility that will be valuable for upgrading renewable and recycled feedstocks. The combination of continuous catalyst regeneration, peri- odic catalyst replacement, and flexible catalyst design will

make the FCC process an attractive choice for introducing the new feedstocks into the refinery, particularly for the more challenging oxygenated feedstocks not suitable for other refinery processes. As more refiners begin to explore the incorporation of renewable and recycled feedstocks into their refining net - works, a detailed study of the chemistry associated with these different feedstocks and the implications it will have on refinery processes and needs for new catalytic materials to enable refiners to achieve their sustainability targets are discussed herewith. Chemistry of sustainable feedstocks Renewable and recycled feedstocks can be derived from many organic-based wastes. The chemistry of these dif- ferent wastes can vary considerably and impact how easily different materials can be converted into desired products. On one end of the spectrum will be polyolefin pyrolysis oils and Fischer-Tropsch waxes, having characteristics similar to conventional oil, making them more easily integrated into existing refinery processes. On the other extreme, highly oxygenated oils derived from biomass will behave much differently than conven- tional oils, potentially requiring significant pretreatment or

Vegetable oils

References

Biomass wastes

Recyclable materials

100%

C H O N S Ash Cl

80%

60%

40%

20%

Poly-olens

Other plastics

Figure 1 Ultimate analysis of various sustainable feedstocks illustrating carbon, hydrogen, heteroatom, and ash content

PTQ Q4 2023