Dec-2021

How to successfully upgrade plastic pyrolysis oil and make it suitable for a steam cracker (ERTC)

As the plastics industry is slowly taking action with recycling and renewables initiatives, the global demand for plastics continues to increase.

Sylvain Verdier, Christian Strebel, Milica Folic and Jesper Gottlieb
Haldor Topsoe A/S

Article Summary

This puts pressure on the industry to keep up, while also meeting increasingly tough legislative restrictions. In the last couple of years, the petchem industry has shown significant interest in specific feedstocks, such as plastic pyrolysis oil (produced by so-called “chemical recycling”) or fatty acid-based feedstocks. Indeed, using such feedstocks would help to decrease GHG emissions, and recycling of plastic waste could significantly help with plastic waste management.

However, several challenges are standing in the way for a successful and large-scale implementation of such solutions:
- Feedstocks: The amount of plastic waste available is significant and is about 150 Mt/y. However, not all types of plastic are suitable for technologies such as pyrolysis. Polyolefins are indeed the preferred feedstocks (high yield of plastic pyrolysis oil and paraffinic composition), but plastic sorting and high demand for PE and PP waste will increase pressure of plastic waste supply in a similar way to what was observed for renewable feedstocks (such as waste oils and fats).
- Solid to liquid technologies: Technologies such as pyrolysis or hydrothermal liquefaction are seen by some as not fully mature technologies. Even if it is not the case, scale can be an issue. Typical size of pyrolysis units would provide about 20,000 t/y of plastic pyrolysis oil and this could be seen as a “drop in the ocean”. Scaling up of such thermochemical technologies is of paramount importance for the successful implementation of chemical recycling.
- Upgrading of plastic pyrolysis oil to meet steam cracker specifications: Steam crackers can have very different feedstocks specifications when it comes to end boiling point, nitrogen content, concentration of halogens such as Cl or F, etc. Therefore, upgrading of plastic pyrolysis oil requires a tailored solution. This is what we offer with our PureStep™ hydroprocessing technology.

Indeed, with Topsoe’s groundbreaking solution PureStep, we can utilise our hydroprocessing knowledge to remove impurities from the liquified feedstock. This means new plastic can now be created from low-grade mixed waste, including tyres, household solid waste, and products containing PVC. From demonstration units to large-size plants, PureStep can fit all needs, although, like other hydroprocessing technologies, economy of scale is obviously a critical factor.

All of this helps keep the industry on the right side of future regulations and market pressure, as well as helping to create a stronger position, more sustainable profile, and wider offering. With 80 years of experience as a world leader in catalysts and proprietary technology, Topsoe is the first and only provider who can offer a solution of this capacity. What’s more, this solution can be fully tailored to specific needs, and together we can create a profitable and responsible circular economy.

For more information contact: ASLI@topsoe.com

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This short article originally appeared in the 2021 ERTC Newspapers, produced by PTQ / DigitalRefining.

You can view the Day 1 Newspaper HERE
You can view the Day 2 Newspaper HERE