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Chemical Recycled ABS Materials for the Transition to a Circular Economy Model

The demand for new, sustainable ABS materials for drug delivery device applications is growing in the healthcare sector. However, because of the risk of cross-contamination, medical regulatory compliance requirements cannot be fully met with mechanically recycled ABS materials. Fortunately, new chemically recycled and bio-based ABS materials are already available, which possess the same chemical composition and properties of virgin medical ABS. This means that they fulfil the same medical applications and meet medical regulation requirements. All the colours that are available as virgin medical ABS can also be used in the bio-circular version, guaranteeing not only regulatory compliance, but also the availability of bright and intense colours in chemically recycled ABS formulations. These types of colours cannot be achieved with mechanical recycled content.

Some clarifications are needed to understand how it is possible for chemical recycled medical ABS to fully comply with medical applications and which are their main sustainability advantages versus medical ABS with entire fossil origin.

There are several types of chemical recycling technologies and different kinds of waste that can be chemically recycled. In this case we are talking about conversion chemical recycling, which is breaking down the target waste through pyrolysis (a thermal decomposition process without the presence oxygen) to obtain an oil like feedstock. Very important is the entrance point of this pyrolysis oil into the ABS polymer supply chain, which is at its very start (upstream). This means, not only before the production of ABS starting raw materials (Acrylonitrile, Butadiene and Styrene), but also before all the steps that are needed to produce such raw materials, without introducing any process change in them. The ISCC+ certification with a mass balance approach guarantees the sustainable nonfossil content, and the whole supply chain can benefit of this with the already existing

 production processes, without making first huge investments which would make this impossible from an economical perspective. Already the chemical recycling processes themselves, the transformations from waste into pyrolysis oil, are represented by different types of expensive alternative technologies that depend on the type of considered waste and that need to be optimised and scaled up to make chemical recycling economically feasible.

An example is the incorporation of pyrolysis oil obtained from used tires in the supply chain production of Styrene. The only change is the partial substitution of Nafta oil with Pyrolysis oil to feed the steam cracking process, that is needed to convert large hydrocarbons contained in the oil into smaller ones. As it happens in the case of 100% fossil oil, the same molecules such as Ethylene and Benzene can be extracted, as it occurs for several other ones. These can be used as reagents in the production of Ethylbenzene and use the same exact processes that is used since many years for the fossil version of these input substances. The next step in the supply chain is the production of Styrene, which is obtained starting from Ethylbenzene with its standard production process which is also the same and has been also optimised since many years. The only difference is that, if chemical recycled content from used tires is present instead of fossil content, each one of these supply chain steps must be certified by ISCC+ with a mass balance approach. The same occurs in the following production passage at the ABS manufacturer, where Styrene is used as raw material to be polymerised with Butadiene and Acrylonitrile to obtain ABS.