Revolutionizing Recycling: From Tires to Roads and Beyond
For millennia, humanity has transformed wood into charcoal using pyrolysis. Today, Jean-Michel Douarre, a visionary in sustainable material research at a renowned French tire manufacturer, envisions adapting this ancient technique for a modern endeavor: converting worn-out car tires back into new ones.
Douarre spearheads a groundbreaking initiative aiming to steer the tire industry towards a more sustainable path. Tires, primarily composed of rubber and petrochemicals, are carbon-intensive. Their production involves burning fossil fuels, releasing significant greenhouse gases into the atmosphere. Pyrolysis, a process of decomposing materials at high temperatures without oxygen, offers a transformative solution. Unlike incineration, pyrolysis thermally breaks down materials, making them suitable for reuse.
This method aligns seamlessly with the European Union’s vision for a circular economy, promoting recycling and minimizing waste. Currently, while most end-of-life tires are collected in Europe, a negligible fraction is repurposed as raw materials for new tires. Douarre’s project, funded by the EU, demonstrates how pyrolysis can convert old tires into a purified form of carbon black, a crucial component constituting 20-30% of a tire. This substance, typically derived from fossil fuels, is essential for imparting color, UV protection, and durability to tires.
The project, dubbed BlackCycle, is a four-year endeavor set to conclude in June 2024. It employs pyrolysis to produce three outputs: a liquid, solid, and gas. By fine-tuning the conditions within the pyrolysis chamber, such as temperature and heating rate, the team can manipulate the quantity and chemical properties of these products. The BlackCycle researchers have adeptly optimized the process to yield substantial amounts of oil from old tires. This oil, akin to its fossil-fuel counterpart, is then transformed into high-grade carbon black.
The project doesn’t stop at carbon black production. Douarre emphasizes the holistic utilization of all byproducts generated during recycling. The gas from tire pyrolysis serves as fuel for the process, while the unconverted oil is earmarked for resin production, potentially contributing to future tire manufacturing.
Europe generates an estimated 3.5 million tonnes of used car tires annually. While the majority are repurposed, the recycling often results in low-value products like rubber granules for artificial sports fields or incorporation into civil engineering projects. However, there’s a growing ambition to create more valuable outputs from tire waste.
The world’s leading tire manufacturer, as per Douarre’s vision, commits to replacing all raw materials in its products with sustainable alternatives by 2050. Recycling tires is a cornerstone of this commitment, not only advancing sustainable practices but also addressing global microplastics pollution, with tires contributing significantly to marine microplastics.
Furthermore, pyrolysis is gaining traction in plastic recycling. Low-temperature pyrolysis transforms plastics into pyrolysis oils, further processed into hydrocarbons. Conversely, high-temperature pyrolysis, exceeding 700°C, enhances gas production, facilitating the breakdown of complex plastics into olefins, foundational elements of new plastics. This process, spearheaded by circular-economy experts, promises to green the plastics industry, with an EU-funded project, Plastics2Olefins, at the forefront, aiming to scale this technology for industrial use by 2027.
While high-temperature pyrolysis holds immense promise for revolutionizing plastic recycling, challenges remain. The quality of input materials significantly affects the process’s efficiency and the quality of the resulting products. The ongoing research aims to identify the lowest quality of plastic waste viable for the process, striving to minimize greenhouse gas emissions and maximize efficiency through renewable energy integration.
Once operational, the anticipated facility will focus on producing polyethylene and polypropylene, prevalent in everyday items, marking a significant stride in sustainable material production.
Disclaimer:
While diligent efforts have been made to ensure the accuracy and reliability of the information presented in this article, it’s important to recognize the dynamic nature of technology and environmental research. Readers are advised to seek additional, contemporary sources to fully comprehend the advancements and implications of pyrolysis in recycling and its broader impact on sustainability and industry practices.
