Plastics are a valuable and versatile commodity in our society that meet a multitude of unique needs for a variety of final applications in different sectors.
However, as plastics have evolved to meet society’s needs, we face growing challenges meeting increased production and disposal requirements. Production can generate undesirable carbon emissions, while we continue to grapple with a waste issue globally. With anticipated forthcoming legislation that will mandate targets for incorporating recycled content, the entire plastic industry is evaluating ways to reduce the environmental impact that plastic solutions have today while balancing the value and benefits they bring to society.
Trinseo sees the value in plastics waste—and that is why we continue to advance mechanical, physical and chemical recycling technologies. As we prepare for regulations and mandatory targets, Trinseo is taking steps to help our customers be ready for those changes. A critical component of this plan is our polymethyl methacrylate (PMMA) depolymerization facility that will be opening this year in Rho, Italy.
Recycling Technologies: Mechanical, Physical and Chemical
As we invest in recycling technologies, we are helping to cultivate a circular economy that can generate new products from pre- and post-consumer wastes. Recycling enables us to recapture the value of plastics from end products like car parts, consumer electronics, lighting, and more.
Historically, mechanical recycling has been the hallmark method of processing waste streams to produce recycled feedstocks. However, continued investment into recycling from the chemical industry and its value chain have enabled us to develop additional scalable solutions that are complementary to mechanical recycling: physical recycling and chemical recycling (also known as advanced recycling in the U.S.).
While mechanical recycling plays an important role in circularity, it has limitations. First, since the materials maintain their color and composition, any additives or contaminants to the original solution are not removed. This means they are only suitable for a limited set of applications. Upcycling then becomes a huge challenge in mechanical recycling.
Second, plastics can become degraded over time and there are limits on how many times they can be mechanically recycled.
And finally, certain materials—such as PMMA cast sheets—cannot be mechanically recycled due to their molecular structure and potential deterioration during the re-melting process.
By introducing new recycling technologies into the system, we can eliminate many of these limitations and begin to process more types of plastic wastes. We can also deliver more consistent and high-quality recycled feedstocks.
Trinseo’s Depolymerization Technology
One form of chemical recycling that Trinseo has advanced through its collaboration in the MMAtwo consortium is PMMA depolymerization. This recycling process enables us to capture high purity methyl methacrylate (MMA) monomers from acrylic waste. Through next generation depolymerization technology and further polymerization steps we can achieve recycled content containing PMMA with similar properties to virgin PMMA: optical clarity, durability, and performance. This means it can be used in many of the same applications, such as automotive taillights and caravan windows, consumer goods and electronics, and more.
Results of the MMAtwo consortium not only showed that the technology Trinseo adopts provides recycled MMA with similar properties to the virgin monomer, but also that there was a reduced environmental impact from the process. Most of the facilities that utilized depolymerization technology, and which were evaluated by the consortium, had at least a 70% reduced carbon footprint compared to facilities producing virgin MMA.1 Not only is this method helping to reduce our global waste issue, but it can also assist with decreasing carbon emissions.
Technologies like depolymerization can help us close the loop on plastics by complementing existing recycling processes. By advancing recycling technologies that yield high-purity results, such as our next-gen depolymerization recycling, we can build demand for recyclate-containing plastic solutions and maintain the necessary waste feedstocks to reduce our dependency on virgin materials.
You can find more information about the impact of depolymerization on circularity in a recent article I published with Sustainable Plastics.
1. PMMA chemical recycling reactor technologies. Polymer Circularity Roadmap: Recycling of Poly(methyl methacrylate) as a Case Study. Edited by D. D’hooge, Y. Marien, J.-L. Dubois. 2022 (65-86)
