According to a recent study by Eunomia Research & Consulting, 85% of materials must be polyethylene (PE) and polypropylene (PP) to successfully utilize chemical recycling (also known as pyrolysis or advanced recycling). it won’t work.
The high levels of PE and PP required for proper use of chemical recycling put pressure on sorting facilities, making this recycling method either impractical or more labor intensive than worth the investment. will be split.
The Alliance to End Plastic Waste has a different opinion.
Alliance to End Plastic Waste (Alliance to End Plastic Waste) is a Singapore-based non-profit organization of companies working towards the common goal of reducing plastic waste by supporting recycling systems. It has been constructed.
The organization was formed in 2019 by multiple companies including BASF, Chevron Phillips Chemical, ExxonMobil, Dow Chemical, Mitsubishi Chemical Holdings, Procter & Gamble and Shell.
On behalf of the Alliance, Eunomia Research & Consulting has conducted a study on the raw material requirements for pyrolysis.
Entitled “Material Quality Guidelines for Pyrolysis of Plastic Waste,” the study interviewed 32 organizations or companies from across the plastic waste value chain in Asia, North America and Europe to optimize recycling. We have gathered information on how proper pyrolytic recycling can be implemented for Make and establish more coordination across the plastics industry.
“This study is intended to be the starting point for a comprehensive conversation about the types of systems that need to be developed.”
Before delving into the specific plastic requirements needed to adopt advanced recycling, the study first explains what this form of recycling entails.
“Pyrolysis is the process of breaking down plastic waste at high temperatures with minimal oxygen to produce pyrolysis oils that can be used to produce new plastics as an alternative to fossil raw materials,” the researchers explained.
Approximately 85% of the material entering the equipment should be PE or PP to achieve the desired results. This will vary depending on the specific facility and its individual equipment and systems, but a common threshold defined in the study is 85%.
In addition to this, advanced recycling is a fairly new field. This means that most facilities that can perform pyrolysis are in the process of formalizing the exact process of how plastics should be treated with a particular technology.
“It should also be noted that many pyrolysis operators are in the early stages of process refinement and optimization and feedstock requirements may evolve over time.”
With this in mind, the research conducted reflected the current state of advanced recycling facilities, which researchers used to advise stream improvements.
“The advantages of pyrolysis include that it is a relatively simple and flexible technique, and that it is typically intended for difficult-to-recycle and highly heterogeneous plastic waste, such as mixed polyolefin plastic waste and multi-material packaging. It includes being
Although relatively simple, attention to contamination levels remains an important factor in ensuring effective chemical recycling.
Nine different feedstock specifications were presented and laid out for pyrolysis.
Various average contamination allowances were provided as follows: PVC/PVDC limit is 1%, PET/EVOH/nylon limit is 5%, polystyrene limit is 7%, metal/glass/dirt/particulate limit is 7%, paper/organic limit is 10%.
Other suggested guidelines include moisture levels and the size of plastic pieces that can be handled.
These are all requirements that should be taken seriously.
To really benefit from the use of advanced recycling, the researchers noted that they had to fit within the already established system set by mechanical recycling.
“It is important to understand how the introduction of raw material specifications for advanced recyclers will interact with existing systems,” they wrote.
Pyrolysis enables the recycling of “difficult to recycle” materials. This means that you can recycle plastics with different grades, colors, odors, and various other additives that normally cannot be processed by mechanical recycling systems.
This means that chemical engineering can become a comprehensive recycling method for a wide variety of plastic products that cannot be processed through conventional recycling.
With all this information determined, the researchers in this study proposed reforming the collection, sorting, and recycling streams across North America and Europe.
Implementing chemical recycling in a way that fills all the gaps in the current recycling system requires an understanding of the overlap between what mechanical recycling of plastics cannot handle and what plastics (and their forms) can handle by pyrolysis. .
The full study can be downloaded here