Global warming is a critical consequence of using fossil feedstocks to produce plastics and energy. In addition, the reserves of fossil feedstocks are going to run out in the next decades considering the actual depletion rates. These, among other considerations, highlight the urgency for a quick transition towards more sustainable feedstocks alternatives, with the need of combining different complementary solutions, from biobased feedstocks to circular feedstocks.
The quickest way to scale up this transition can be reached by feeding the petrochemical cracking units with sustainable alternative feedstocks instead of fossil feedstocks. Such new feedstocks can come from advanced recycling routes from waste of different types (bio-based (e.g. organic waste, used cooking oil), circular (e.g. plastics waste) or mixed (e.g. used tyres with biogenic certified content) and can be added to the crackers in form of pyrolysis oil, hydrotreated vegetable oils, etc. substituting fossil oil in a certain percentage).
As first ABS plastic manufacturer to get the ISCC+ certification, ELIX Polymers includes in its polymerisation process input monomers with certified origin from pyrolysis oils (chemical recycled waste) or bio-based feedstocks. The types of waste and bio-based sources are the ones described above. The implemented ISCC+ traceability certification system guarantees the circular or bio-circular loop and the inclusion of waste as feedstock alternative. ABS with ISCC+ certified recycled or bio-attributed content has the exact chemical composition as virgin ABS from fossil feedstocks. For this reason, a medical ABS ISCC+ certified from recycled and bio-attributed feedstocks maintains biocompatibility properties according to ISO10993 and is fully compatible with all stringent regulatory requirements of the medical device sector. The adopted ISCC+ certification follows a mass balance approach.
In this article, we explain the importance of a mass balance approach for plastics production (note: not for fuel production), making specifical reference to ABS plastics production as example. This topic, called mass balance fuel-use exempt, has been already recognised by many associations in the plastics supply chain and exposed to the European Commission to take quick actions. With such approach, the recycled or bio-attributed content is formally assigned from raw materials to production lots that correspond to the orders of specific OEM customers and moulders.
These customers are only the ones who contribute to the switch from fossil feedstocks to sustainable feedstocks, including biobased feedstocks and chemical recycled waste. Because it is a pure accounting method, the sustainable feedstocks are physically distributed in all the material batches produced, including the ones that are supposed to contain only fossil feedstocks. Nevertheless, it would be an injustice to recognise the choice of sustainable alternatives also to those customer OEMs who are not making any effort for it. For this reason, the concept of sustainability credits is introduced, to grant only the OEM or moulder who specifically purchase them to get the sustainability benefits of ABS material in terms of CO2 emissions reduction, reduction of fossil depletion rate and chemical recycled waste content or bio-attributed content.
The mass balance approach exists because we are living a transition period from fossil to sustainable feedstocks. This transition would take too many years and much heavier investments to reach the scale of volumes required to make the difference. There is not enough time, since it is estimated that fossil feedstocks will run out in few decades counting from today. As previously mentioned, the sustainable feedstocks in form of oil (e.g. pyrolysis oil or hydro-treated vegetable oils) ISCC+ certified can directly substitute fossil oil. These oils are used to feed the petrochemical crackers, to produce the basic molecules (e.g. ethylene, benzene) that are used in the plastics supply chain, including ABS materials.
